VOLUME 109, NUMBER 5, September–October 2021 American Scientist

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How hormone-like pollutants DISRUPT MENSTRUAL CYCLES

AMERICAN

Scientist September–October 2021

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Volume 109 • Number 5 • September–October 2021

Feature Articles

258 From the Editors

296

259 Letters to the Editors 262 Spotlight Fixing broken biological clocks • Economics and public health during a pandemic • Baseball spin doctors • The wild heart of the Milky Way • Briefings 270 Sightings Giants in traffic 274 Perspective Tunnel vision Dean J. Tantillo 278 Engineering What lessons will be learned from the Florida condo collapse? Henry Petroski 282 Arts Lab Etching the landscapes within Kim Moss

Scientists’ Nightstand 312 Book Reviews Finding hope in community-based conservation • Addressing global pollution in a capitalistic world • Chalkophilia

From Sigma Xi 317 Sigma Xi Today Of roots and fruits • Sigma Xi installs two new chapters • Distinguished Lecturers • Student Research Showcase award winners • Conference breakout sessions

288 288 The Shift to a Bird’s-Eye View Remote sensing technologies allow researchers to track small changes on a large scale and enable studies of far-flung places from the comfort and safety of home. Elizabeth M. P. Madin and Catherine M. Foley 296 How Endocrine Disruptors Affect Menstruation The ubiquity of phthalates and other substances known to interfere with hormonal pathways disproportionately harms people with periods. Kate Clancy 304 Designed for Change Active products that adapt to fit users’ needs can be stronger, cheaper, and more comfortable than traditional, static objects. Skylar Tibbits

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The Cov er Bora Bora in French Polynesia has the reputation of being a pristine paradise, but tourism has altered the island’s ecosystem. A coral atoll encircles the island group, creating a gentle lagoon in the middle of the Pacific Ocean. Luxury hotels have built villas directly over the water, and one resort even created an artificial island to accommodate more guests. Snorkeling tourists might not recognize the signs of an unhealthy ecosystem, but remote sensing technologies such as satellites provide ecologists with an overview of the changes. This view from above can help researchers identify areas in distress so that they can develop intervention strategies before it is too late. In “The Shift to a Bird’s-Eye View” (pages 288–295), ecologists Elizabeth M. P. Madin and Catherine M. Foley detail how remote sensing technologies have changed their approaches to researching isolated coral reefs and inaccessible penguin populations. The techniques they describe are not limited to ecological projects; remote sensing tools have also helped document humanitarian crises, and they are fundamental to the transition that many researchers have made from the field to their homes in order to maintain social distancing during the COVID-19 pandemic. (Cover image from GeoEye/Science Source.)

From the Editors

AMERICAN

Scientist

Beautiful Data

www.americanscientist.org VOLUME 109, NUMBER 5

I

n this issue’s Sightings column (“Giants in Traffic,” pages 270–271), I spoke to a group of Chilean researchers about their study that tracks blue whales and ships. The team used multiple types of data to create detailed maps for their peer-reviewed paper, but for social media, they created a GIF of a week in the life of one whale, showing how it had to constantly duck and dodge around boats. The GIF raised questions from other scientists about the scale, the speed of the display, whether it was real data or an animation, and whether the whale’s position was at the surface or at depths below the boats—points that were all addressed in the researchers’ paper. But for most of the people who viewed the GIF, which was widely shared, the whale’s plight simply evoked sympathy and awareness. As a member of the research team, Luis Bedriñana-Romano, said to me, “You can put up a lovely chart with graphics and it’s going to only reach the scientific community. But if you have a nice data visualization, it can reach everyone.” Data scientist Kurt D. Bollacker, who wrote in our pages in 2010, has become his own internet meme for having said, “Data that is loved tends to survive.” Bollacker’s quote sticks with people, because it clearly expresses the idea that data only become useful if they are seen and understood. The theme of how to express data so it is immediately accessible runs across many articles in this issue. Tracking whales with satellites and tags comes up again in “The Shift to a Bird’s-Eye View” (pages 288–295), by Elizabeth M. P. Madin and Catherine M. Foley. These researchers discuss the many ways that remote sensing technologies have changed the data that are available to scientists, from studies of coral reefs and penguin colonies, to refugee displacement and pollutant monitoring. Making health data approachable is also the goal of Kim Moss in this issue’s Arts Lab, “Etching the Landscapes Within” (pages 282–287). Moss uses a different path to data visualization by etching microscopic body processes onto glass plates and illuminating them with colored lights, a beautiful and memorable way to consider tissue damage and repair processes. And in this issue’s Q&A (pages 266–267), economist Micah Pollak describes his efforts to take complicated data sets related to the pandemic and create visualizations that he can share on social media, both to make the data understandable and to spark discussion and iterative revision of graphics to address public questions. Understanding processes on scales too small to be seen is a central idea in Perspective (“Tunnel Vision,” pages 274–278) in which Dean J. Tantillo uses the metaphor of tunneling through hills to make a quantum mechanical phenomenon more relatable. And on a metabolic level, in “How Endocrine Disruptors Affect Menstruation” Kate Clancy displays how chemicals such as phthalates can alter the function of endometrial cells. In Spotlight (“Fixing Broken Biological Clocks,” pages 262–264), Katie L. Burke details how biological clock cycles are tied into a particular cell receptor pathway. In our July–August issue, the data visualization that went into space as a message to potential aliens on a plaques carried by the Pioneer 10 and 11 spacecraft was a point in “Who Should Speak for the Earth?,” by John W. Traphagan. In the print version of the article, the caption about Pioneer 10 contained an error that was introduced in editing, which is corrected in this issue’s errata section as well as online. In the interest of correct data transmission to our readers, we apologize for the error. Data can take us from the smallest to the largest phenomena, and we return to space in this issue’s Infographic (“The Wild Heart of the Milky Way,” page 272). A breathtaking new image of our galaxy’s center has been impressing scientists, and our senior consulting editor Corey S. Powell breaks down just what the new image shows. We hope you’ll join us on this issue’s tour of remarkable data at all scales. —Fenella Saunders (@Fenella Saunders) 258

American Scientist, Volume 109

Editor-in-Chief Fenella Saunders Managing Editor Stacey Lutkoski Senior Consulting Editor Corey S. Powell Digital Features Editor Katie L. Burke Senior Contributing Editors Efraín E. RiveraSerrano and Sarah Webb Contributing Editors Sandra J. Ackerman, Carolyn Beans, Emily Buehler, Christa Evans, Jeremy Hawkins Editorial Associate Mia Evans Art Director Barbara J. Aulicino SCIENTISTS’ NIGHTSTAND Book Review Editor Flora Taylor AMERICAN SCIENTIST ONLINE Digital Managing Editor Robert Frederick Publisher Jamie L. Vernon EDITORIAL CORRESPONDENCE American Scientist P.O. Box 13975 Research Triangle Park, NC 27709 919-549-4691 • [email protected] CIRCULATION AND MARKETING NPS Media Group • Beth Ulman, account director ADVERTISING SALES [email protected] • 800-243-6534 SUBSCRIPTION CUSTOMER SERVICE American Scientist P.O. Box 193 Congers, NY 10920 800-282-0444 • [email protected] PUBLISHED BY SIGMA XI, THE SCIENTIFIC RESEARCH HONOR SOCIETY President Robert T. Pennock Treasurer David Baker President-Elect Nicholas A. Peppas Immediate Past President Sonya T. Smith Executive Director Jamie L. Vernon American Scientist gratefully acknowledges support for “Engineering” through the Leroy Record Fund. Sigma Xi, The Scientific Research Honor Society is a society of scientists and engineers, founded in 1886 to recognize scientific achievement. A diverse organization of members and chapters, the Society fosters interaction among science, technology, and society; encourages appreciation and support of original work in science and technology; and promotes ethics and excellence in scientific and engineering research. Printed in USA

Letters Special Issue Feedback

SPECIAL ISSUE

WHISTLEBLOWERS • ETHICAL AI • PUBLIC HEALTH ALIEN RIGHTS • INCLUSIVE STEM • GENOMICS

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Scientist www.americanscientist.org

July–August 2021

TRUST WORTHY SCIENCE

July–August 2021

To the Editors: I had just renewed my membership to Sigma Xi when I received the July–August special issue of American Scientist.

To the Editors: Your July–August issue was very disappointing; very little science and a lot of fluff about ethics! Maybe your magazine just isn’t for me. I want to learn something new

Volume 109 Number 4

Judith Stribling Salisbury, MD

Maria Stacewicz-Sapuntzakis Sterling, VA

American Scientist

To the Editors: The special issue on Trustworthy Science (July–August) was the best of many outstanding editions of American Scientist. I was astounded at the honesty, intelligence, insight, and deep understanding of the complexity of the relationship between science, scientists, and society. Every article brought clarity and focus to issues of deep importance. It’s as if subjects such as whistleblowers and trust in science are examined and presented for the first time, because no one before has treated them with such care and humanity. The beautiful quote from Chanda PrescodWeinstein’s book The Disordered Cosmos (Nightstand) could describe much of what is contained in this issue: “What goes undiscussed is that it is not the only way to understand the origins of the world.”

I hope the future issues will be more scientific and less political or I will regretfully cancel my membership.

about science, not read rants about someone’s opinions about ethical issues. Stephen Hepp Montesano, WA Editors’ note: During the COVID-19 pandemic, the hypotheses, conclusions, and best practices for dealing with the disease were revised (and revised again) in light of new data and circumstances. Some malicious groups jumped on these revisions to cast doubt on mask wearing, vaccines, and science in general. Many researchers responded that this iterative process is how science works: You reconsider your hypotheses and reevaluate your conclusions when new evidence becomes available. The evolving approach to the pandemic shows that science and peer review are working, not that science is unreliable or “wrong.” Science itself must be held to the same standards of rigor and honesty. When it becomes clear that large parts of society have been excluded from involvement in science, or that some data have been gathered in a biased manner, or that some conclusions have been based on assumptions rather than on empirical findings, scientists should be eager to reconsider past work and present practices, no matter how established they might be. The processes of

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An Antidote to Climate Despair

Venus Tectonics Look Like Pack Ice

Earth’s nearby neighbor seemed inactive, but new maps and models have exposed its complex volcanic and crustal deformation surface features. www.amsci.org/node/4826

The book All We Can Save is an anthology of essays and poems by a diverse group of feminist climate experts and activists. A project has grown out of the book that aims to nurture a climate community “rooted in the work and wisdom of women.” www.amsci.org/node/4815

Trees of Life

Data Communication

The second episode of “D&I ComSci,” American Scientist’s science-for-all podcast, examines how scientists can visualize data inclusively—speaking to audiences of different cultures, visual abilities, and scientific experience levels. www.amsci.org/node/4804 Bettering the Lives of Animals

In her book Animals’ Best Friends, Barbara J. King, an expert on animal cognition and emotion, suggests steps we can take to begin living more harmoniously with our fellow creatures. www.amsci.org/node/4821

Art and Environmental Education

Jennifer Landin, an associate professor at North Carolina State University in the Department of Biological Sciences, explores how art and science can work together to help humanity tackle seemingly overwhelming problems, such as climate change. www.amsci.org/node/4802

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Timothy P. Sheahan, an assistant professor of epidemiology at the University of North Carolina at Chapel Hill Gillings School of Global Public Health, discusses how the generation of robust in vitro and in vivo models of coronavirus diseases is essential to accelerating the development of drugs and vaccines. www.amsci.org/node/4825

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To the Editors: After reading “Plants as Teachers and Witnesses” by Beronda Montgomery (January–February), I could feel the author’s love for the beauty and complexity of trees. The article was beautifully written, which made it fun to read as well as informative. I will now forever look at a tree not just for its aesthetics, but with an understanding of the complexities of its life. I would like to thank the author for such an interesting perspective. Donald Leonhardt Bay Shore, NY

Erratum http://www.amsci.org/blog/

Preparing for Tomorrow’s Pandemics, Today

doing science and communicating about science are now their own fields of study with their own deep literature. They are as worthy of discussion as any other new discovery or result, especially because findings in these fields have important implications for every other discipline. Ethical research practices should be of concern to anyone who wants to be certain that their medicine, infrastructure, food, and water are safe; that science is accessible to the widest range of minds; and that there are mechanisms for speaking up effectively if something goes awry. There is no partisan implication to the goals of health, safety, and opportunity.

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In “Who Should Speak for the Earth?” by John W. Traphagan (July–August), the last sentence of the caption on page 211 should read as follows: “When message-carrying spacecraft such as Pioneer 10 are launched, they establish a precedent and set a challenge to do better with future communications.” We have corrected the digital and online versions of the article.

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Spotlight | Circadian biology, sleep research, and neuropharmacology

Fixing Broken Biological Clocks Scientists are looking for pharmaceutical ways to mimic the effects of light on the brain’s clockwork. At one point or another, we’ve all hit the wall of sleep: the point when you are so exhausted that you cannot stay awake, no matter how bright it is outside or how much caffeine you have consumed. Until recently, though, no one understood the exact molecular mechanisms responsible for this ubiquitous experience. Circadian biologists have long been aware that exposure to light can shift a mammal’s sleep-wake cycle, but they haven’t been able to work out why light exposure becomes ineffectual when an animal is sleepdeprived. Sleep researchers have also known that caffeine delays sleep by blocking the action of a molecule called adenosine. As an animal uses energy while it is awake, adenosine builds up in the body—for example, through the breakdown of a key metabolic molecule, adenosine triphosphate (ATP)— and induces a sense of sleepiness. But until recently, no one had determined how adenosine made that happen. A study published in Nature Communications in April, led by neuroscientist Aarti Jagannath, circadian biologist Russell Foster, and pharmacologist Sridhar Vasudevan, all at Oxford University, marks a major advance in untangling the roles of adenosine and light in sleep. In the process, the researchers discovered a drug that may mimic the effects of light exposure, with potential applications to health problems ranging from sleep dysfunction after eye injuries to schizophrenia. This interdisciplinary realm of research spanning the team members’ careers has led them to the realization that the sleep-wake system draws from all the key neurotransmitter systems, and that the sleep-wake cycle is a global brain event. We all have a built-in clock system that keeps our sense of time and determines when we are active and when we are sleepy. Light entrains this clock system when it is detected by specialized nerves in the eye, called photo262

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sensitive retinal ganglion cells, which were first identified in 2002, setting off a flurry of research on light entrainment over the following two decades. These nerve cells send signals to turn on key genes called Per1 and Per2 in the brain’s “master clock,” the suprachiasmatic nuclei. This master clock in turn regulates through molecular signaling many aspects of the clock system in various tissues throughout the body. Animals are particularly sensitive to light at dawn and dusk, when exposure to light can delay or advance our sleep-wake cycle—a trait that we can use to help alleviate jetlag (see “Adapting Your Body Clock to a 24-Hour Society,” November–December 2017). Diurnal species experience big delays in our sleepwake cycles when exposed to light at dawn, and small advances at dusk. Nocturnal species such as mice are the opposite: Light exposure at dusk delays wakefulness substantially, whereas at dawn it brings on sleep a bit sooner (see the phase response curve on the facing page, top panel). “A mechanistic explanation for that wasn’t appreciated before,” Foster says. “But we can explain that phenomenon almost exclusively within the context of adenosine.” What the research team found was that as adenosine builds up during the time one is awake, it triggers a signaling pathway that results in feeling sleepy—the same signaling pathway, indeed, that light acts upon. Light turns on this pathway (though it has a mechanism for turning itself off, so that the clock’s sensitivity remains heightened for a short period); adenosine inhibits this pathway. Adenosine receptor antagonists such as caffeine or the drug Jagannath’s team tested disrupt this pathway, so that the feeling of sleepiness is delayed. “One of the interesting outcomes of this paper is that they show how the chemical adenosine is able to code for how tired you are, and that can then feed back to the circadian clock to in-

fluence how the clock responds,” says Michael Antle, a psychologist at the University of Calgary who has also studied circadian clocks and adenosine and who was not involved with the study. “You respond one way when you’re tired, and in a different way when you’re not tired.” Jagannath and Foster first teamed up as they tried to figure out the molecular pathways by which light influences circadian rhythms. They later brought Vasudevan into the collaboration to explore drugs that could act on the same pathways. The team started off by looking at compounds that shift the clock in cells in culture. They noticed that drugs that disrupt the binding of adenosine to its receptors had big effects on the cells’ expression of biological clock genes. “This was around the time when these studies on caffeine were coming out, showing that caffeine could affect circadian rhythms in humans, and also in mice,” Jagannath says. Because caffeine is an adenosine receptor antagonist (that is, it inhibits adenosine from binding to its receptors), she and her team wanted to figure out how adenosine and the clock system were talking to each other. They found that adenosine signaling is a fundamental part of the machinery that regulates the body’s sense of time. Light can advance (+) or delay (–) sleep onset in a mouse depending on its day-night and sleep-wake cycle (top, phase response curve). During the time the mouse is awake at night, adenosine builds up, inducing a sense of sleepiness. Light and adenosine both act on a two-pronged signaling pathway (shown in the purple expansion box) affecting the expression of the genes Per1 and Per2—adenosine inhibits the pathway, whereas light or adenosine receptor antagonists activate it (bottom panel). On one prong of the pathway, light or adenosine receptor antagonists activate a cellular messenger molecule called cyclic adenosine monophosphate (cAMP), which is a derivative of ATP, and a transcription factor that regulates gene expression called cAMP response element binding (CREB). On the other prong, they activate calcium (Ca2+) signaling, followed by a master regulator of DNA transcription called extracellular regulated kinase (ERK), as well as another transcription factor called activator protein 1 (AP-1). These two prongs, cAMP and AP-1, come together to result in the full expression of clock genes Per1 and Per2, which are responsible for shifting the clock.

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Adding adenosine antagonists reverses this inhibitory signaling and mimics the effects of light, adding to the light sensitivity of the clock.

photosensitive retinal ganglion cells adenosine receptors in SCN

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adenosine receptors phase response shift Ca2+ and cAMP pathway inhibited. Per1 and Per2 production stops. Ca2+ cAMP

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Barbara Aulicino

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clock sensitivity high mouse stays awake longer

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“This space of adenosine receptor antagonists is fairly well explored in terms of the pharmacology,” Jagannath explains. “There are drugs out there that are in the clinic, or at least in clinical trials, in this space. We said, ‘Can we try any of them, and see if they have an effect on shifting rhythms in mice?’” What Jagannath’s team worked out is that light and adenosine both act on a two-pronged signaling pathway affecting the expression of Per1 and Per2: Adenosine inhibits the pathway, and light or adenosine receptor antagonists activate it (see infographic on previous page). These two prongs (cAMP and AP-1) come together to result in the full expression of clock genes Per1 and Per2, which are responsible for shifting the clock. Once the team worked out the pathway in cell culture, they moved to testing how an adenosine antagonist drug affected the sleep-wake cycle of mice. Just as would be expected with light exposure at different times of day, giving the drug to mice at early dusk caused their clock to shift later, whereas giving it in the middle of the day (when mice are usually asleep) caused their clock to shift earlier. “Importantly, if you antagonize the A1 and A2A receptors [two adenosine receptors] in combination with the light pulse, the light pulse will have a much bigger effect on the clock,” Jagannath says. (See graph on the bottom right of the infographic.) It took about five years to work out the molecular pathway by which adenosine and the biological clock interact. “The signaling pathways that we decoded turned out to be not as simple as we thought,” Jagannath says. “For example, we needed to do a transcription factor binding assay, and that involved assaying 3,000 different transcription factors with a high-throughput screen, which Ueli Schibler at the University of Geneva had developed. The actual delineation of that pathway was a monumental amount of work. Part of what’s been holding this field back is that people would have tried smaller experiments on different sides and seen conflicting things that they couldn’t quite put together. We needed to hammer at it for a long time before we managed to understand what was going on at the full scale.” The work also brings together two disciplines that, as Foster puts it, “simply didn’t go to the same meetings.” But finally bringing together sleep research, which has a medical history, and circadian biology, which has focused on 264

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ecology and evolution, has yielded exciting returns. “This paper shows how you can consider advances from both fields, put them together, and make the bigger picture much clearer,” Jagannath says. The team is now working with Blind Veterans UK to find clinical trial participants who have lost the ability to maintain a consistent internal clock. “The consequences of losing the eyes completely is getting up a bit later and later and later, about 10 or 15 minutes each day,” Foster explains. “Can we give the

The circadian rhythm affects not just sleep but such things as metabolism, mood, and alertness. drug to those drifting individuals and fool their clock into thinking it’s seen light?” Although many people who are born blind have photosensitive retinal ganglion cells and can entrain their biological clocks even though they cannot see, people who sustain eye injuries, such as blinded veterans, often have these nerve cells damaged as well. Antle notes that differences between mice and humans need to be considered when interpreting this study’s results. “Adenosine levels in a mouse will be highest in the later part of the night, when they are exposed to dawn light, whereas for us, our adenosine levels will probably be highest around dusk,” he says. “So the responses they’re seeing [in mice] can be different than what you might expect in a person.” He also points out that “adenosine pharmacology is really complex,” and that more work is needed to fully understand how this system works in mice and people, and where in the body the drug is acting to result in the outcomes the Oxford team has observed. The team is planning to begin clinical trials in blind veterans in the fall through their spinout company, Circadian Therapeutics, because the drug they tested in mice has already been shown to be safe in humans when tested for another purpose. “The adenosine A1 and A2A antagonist has a rich history of evaluation for Parkinson’s disease,” Vasudevan says. “However,

for those disorders, the drug failed in phase 3. But what we knew was that the drug was safe for human use. That’s basically saved us 5 to 10 years in the process and a lot of money as well.” Although caffeine is also an adenosine antagonist, the authors say it doesn’t work well for treating dysfunction in the regularity of the sleep-wake cycle. “Caffeine has some other effects than just engaging with adenosine receptors,” Vasudevan says. “Its half-life is between four and six hours. With our drug, you hit the receptor, make the change you want, and then it’s out of the system.” The authors plan to explore treatments for not only those who have lost their eyes, but also other health problems that include issues with sleep regularity as a symptom. Foster’s lab and colleagues have made strides in the past 10 years showing that disrupted circadian rhythms are an aspect of many mental health disorders, such as schizophrenia and bipolar disorder. “There’s a genuine mechanistic overlap between the pathways that generate normal sleep and the pathways that generate normal mental health,” Foster says. “Daniel Freeman [a psychiatrist at University of Oxford] was able to partially stabilize sleep-wake in schizophrenia [patients] and reduce levels of delusional paranoia by 50 percent. That suggests that the sleep-wake systems represent a new therapeutic target.” What these researchers have come to appreciate is that if you have a neurotransmitter defect that predisposes you to mental illness, it almost certainly affects sleep. Exactly how the underlying causes of such disorders are related to the sleep systems is not yet known, but is an exciting area of research. “Whenever there’s a circadian rhythm disorder, often it manifests as sleep disturbance,” Vasudevan says. “When you go to your GP and say, this is a problem, you get a hypnotic or a sedative that puts you to sleep. The circadian rhythm extends far beyond sleep. It controls metabolism, your mood, how sharp you are at what time of the day, your alertness, all kinds of things. But your existing medication doesn’t fix any of that. The fact that we can make a fundamental drug that can treat the underlying cause of the disorder is exciting, because it’s a whole new treatment paradigm.” —Katie L. Burke Am

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| Micah Pollak

Economics and Public Health During a Pandemic An issue that has loomed large in public discourse about the COVID-19 pandemic is the question of how the various shutdowns and stay-at-home orders have affected the economy. Micah Pollak has been trying to answer that question through research and the creation of data visualizations that put the pandemic in context. Pollak is an associate professor of economics and the director of the Center for Economic Education and Research in the School of Business and Economics at Indiana University Northwest in Gary, Indiana. His research interests cover a wide range of topics, including data analytics, health economics, financial economics, and regional economics. Pollak says that the rich data available in nearly real time throughout the pandemic have created an unprecedented opportunity for social scientists to study changing trends. He has been applying his teaching experience toward communicating his findings to the public using graphs and other visualizations on social media. Pollak spoke with Scott Knowles, a historian of risk and disaster at the Korean Advanced Institute of Science and Technology, on his daily podcast, COVIDCalls. On the podcast, Knowles speaks to guests about their research and the far-reaching effects of the pandemic. This interview is part of an ongoing collaboration between American Scientist and COVIDCalls. It has been edited for length and clarity. What can be said at this point about the effect of this pandemic on the national economy?

What forms of conventional wisdom have been provoked and pushed during the pandemic?

In some ways we’re surging back much faster than we would have expected, because nothing was permanently altered. But in other areas, in particular labor, we’re seeing big consequences. I don’t think it’s a coincidence that national headlines have focused on labor—such as unemployment insurance and extensions of benefits—because that’s where I think we’ll see the most long-term changes as a result of the pandemic.

Early on, whenever a region or a nation shut down, there was this automatic reaction, “That’s going to kill the economy.” A lot of economists, including myself, felt that wasn’t the case. Our economy was hurting because of the pandemic. The way that you address that economic problem is by dealing with the pandemic. You need to lower the spread to the point where people feel comfortable again.

How do you think about the discourse last year around the relief payments in the United States?

The relief payments were an equalizer, in the sense that there was a minimum amount of money that you could count on. There is pretty strong evidence that they had a significant effect on people’s livelihoods. They kept many people out of poverty and probably saved lives as well. I’m sure the payments will be the focus of research in years to come. In a sense, we had a miniexperiment with universal basic income. And I think that changed people’s perspectives on what income is and how the government could help people. 266

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How has the economy of Indiana, where you work, been affected by the pandemic?

Northwest Indiana is an industrial region: a lot of steel mills and manufacturing. The steel mills remained open as much as possible. There were instances where there was an outbreak and sections would have to be closed down. Before COVID, we were in a trade war, which created challenges in Northwest Indiana, because we export a lot of steel and soybeans [which were subject to international tariffs]. The trade war is still going on. Certainly, in terms of employment, we don’t see jobs coming back rapidly here. We’re still well below the prepandemic level. I think that surprises a lot of people, especially because

we’re not just talking about food service jobs, we’re also talking about manufacturing jobs and higher-paying jobs. How have you approached taking complicated data sets and rendering them into something that a nonexpert can understand?

My goal has been to create visualizations that help people understand the data. One of the first visualizations I made, which created lots of controversy, was comparing flu deaths in Indiana by week with COVID deaths, just putting them side by side. Objections people raised online included: We don’t test flu and COVID in the same way. And: We don’t have a vaccine for COVID, but we do for flu, so you have to adjust for whether people are vaccinated or not. So I refined my visualization and said, “Okay, if you don’t like this part of the assumptions, we can change them a bit and make it more compelling.” It’s an iterative process. The objections fit with what I was trying to do perfectly fine, because I’m trying to distill the information. The first graph I made used last year’s flu data. Then, someone pointed out that last year was an unusually light year. So I said, “Let me go back and find the deadliest flu season in the past 20 years in Indiana, and use that instead.” And then

I slowly whittled away at the objections. Some people you’ll never convince, but if you can preemptively deal with as many objections as possible, then that makes the visualization more effective. Social media can be somewhat of an echo chamber, but I do think that it’s hard to disassemble something that has gone through multiple iterations, has had feedback from lots of different people, has been improved upon, and has sources listed. One well-designed visualization has the potential to demolish a lot of misinformation. It does take more work to make one good visualization, but once it’s created, it’s hard to argue with, because everything is laid out clearly.

everything under the Sun was happening. Some places were sticking with 100 percent e-learning the whole year; other places were in-person full time. We saw this as a natural experiment

You and an interdisciplinary team of colleagues published a paper in Clinical Infectious Diseases on the effect school reopenings had on the spread of SARSCoV-2 in Indiana. This local study has broad implications regarding the return to school in the middle of a pandemic. What did you learn?

where we can see whether districts that were mostly in-person had a lot of cases, and whether those that were doing e-learning reduced spread. [For a summary of research on this topic, see “Does InPerson Schooling Contribute to COVID-19 Spread?” at amsci.org/node/4753] There had been studies about inperson instruction, but they mostly focused on the classroom itself. Those studies are problematic because there were all sorts of issues with data col-

Indiana didn’t standardize how schools were going to reopen—it was left up to the local school district and the county health department, which meant that

www.americanscientist.org

“One well-designed visualization has the potential to demolish a lot of misinformation.”

lection. Schools had an incentive not to encourage parents to test their kids as much, and parents sometimes didn’t want to get their kids tested, because at the time the test was invasive. We came up with a study idea looking at school districts and counties to see how they reopened, and then at the community spread. If there’s spread that’s happening in the classroom, then we’ll see a rise in cases in the community as well. We found that during the 90-day period after schools opened, the additional students would have added about 1 percent more cases. I think the true value of the study was that it put a numerical value on the risk of opening schools in person. And then it’s up to the individuals to decide whether that’s a risk they’re willing to take or not. We’re hoping that the study will be helpful for policy decisions, but the circumstances have changed. We did this study before the Delta variant, and we have more variants coming. We also have a large percentage of the population vaccinated. Am

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Spotlight | Grasping for more torque

Baseball Spin Doctors Sticky substances can improve a pitcher’s grip and enable throws with greater spin, leaving batters at a disadvantage.

Cheating in baseball is as old as the game itself, and pitchers’ modification of the ball’s surface is part of that long history. Adding to the lore of cheating is a new scandal involving pitchers who may be applying sticky substances—what players refer to as “sticky stuff”—to baseballs. Major League hitters are striking out this season nearly one in every four times they step to the plate, compared with one in six times in 2005. As a sports physicist and longtime baseball fan, I’ve been intrigued by news reports that applying sticky substances to balls can make pitches spin faster. And if pitchers can throw their fastballs, curveballs, and sliders with more spin than in previous years, their pitches will be tougher to hit. How does science explain all this? Increased Friction and Torque If you want to understand what all the sticky fuss is about, you need to know some friction basics. You’ve surely tried to unscrew a lid from a stubborn jar. If there isn’t enough friction between your fingers and the lid, you may not be able to exert enough torque—the rotational analog of force—to get the lid to turn. One way to get more torque on the lid is to increase the frictional force. In my home, we use a circular piece of rubber to increase friction and help open tough jars. Pitchers want more friction between their fingers and the baseball, and they are supposedly using some interesting substances to accomplish this. According to a June 4, 2021, article in Sports Illustrated by Stephanie Apstein and Alex Prewitt, substances that pitchers have experimented with include drumstick resin, surfboard wax, Tyrus Sticky Grip, Firm Grip spray, Pelican Grip Dip stick, and Spider Tack—”a glue intended for use in World’s Strongest Man competitions and whose 268

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advertisements show someone using it to lift a cinder block with his palm.” The article noted two instances of these doctored balls making their way into a dugout: One was so sticky that players could see fingerprints on it, and the other would stick to the downward-facing palm of an open hand. All of these sticky substances increase friction and thus give pitchers a better grip on the ball.

A batter swings where he thinks he’ll make great contact, but because of the sticky stuff and extra spin, the ball crosses the plate lower than expected. More Spin Equals More Strikes Today’s sticky fingers are the latest attempts by players to gain an unfair advantage. But how does sticky stuff make a pitch harder to hit? It helps increase spin rate. Unless the pitcher is throwing a knuckleball, which has very little spin, a baseball leaves a pitcher’s hand spinning at well over 1,000 revolutions per minute. That spin creates a force—let’s call it the spin force—that causes baseballs to move and curve in ways that can throw off hitters. As air smashes into a moving baseball, it doesn’t wrap completely around the ball—it separates off the

surface before reaching the back of the ball. Think of water flowing along the sides of a moving boat. The water doesn’t smoothly wrap around the back of the boat—there is a wake of turbulent water flowing out behind it. But when a rudder turns the boat, the wake moves off to one side. Newton’s third law states that for every action, there is an equal and opposite reaction. So if the boat pushes water in one direction, water has to push the boat in the opposite direction, causing the boat to turn. The same idea applies to a spinning baseball. If the baseball is spinning, the wake of air behind the ball will be asymmetric. So the spin force pushes the ball in the opposite direction from which the wake of air is pushed. Consider an overhand curveball. In this pitch, a Major League Baseball pitcher pulls down on the front of the ball when he releases it, generating topspin. A topspinning curveball pushes air upward off the back of the ball, just like a wake coming off one side of a boat. Because the ball pushes the wake of air upward, the air’s force on a curveball is downward. Curveballs thus experience a push downward on their way to the plate, all thanks to the spin force. How Effective Is Sticky Stuff? Here is where the alleged cheating comes in to the story. As with pitchers in the past, a Major League pitcher today could potentially put sticky stuff on his fingers in the locker room, stick some to his uniform, or even get some from a teammate. The substances starring in the current scandal would help create more spin. A good pitcher can throw a curveball at 137 kilometers per hour (85 miles per hour) and with a spin rate of 2,400 revolutions per minute with about 89 newtons of friction force between the pitcher’s fingers and the ball. Freely available pitch data show that some pitchers have increased their spin rate by about 400 revolutions per minute on curveballs compared with previous seasons. That’s a 17 percent increase in spin rate and requires a 17 percent increase in—or more than 13 additional newtons of—friction force, which could be the result of sticky substances.

Associated Press/AP Images

A substance can be seen on the throwing hand of New York Yankees pitcher Michael Pineda in this April 10, 2014, photo of him delivering a pitch in a game against the Boston Red Sox. Two weeks later, in another game against the Red Sox, an umpire found pine tar on Pineda’s neck, which he was presumably applying to his hand to improve his grip on the ball. Pineda received a 10-game suspension for violating Major League Baseball’s rules against pitchers doctoring baseballs.

For an overhand curveball, an extra 400 revolutions per minute of topspin can lead to more than 5 centimeters of additional vertical drop—which

just happens to be the thickness of the sweet spot of a baseball bat. In other words, a Major League Baseball batter familiar with a pitcher’s curveball

might swing where he thinks he’ll make great contact, but because of the sticky stuff and extra spin, the ball will cross the plate 5 centimeters lower than the batter expects. He’ll either miss the pitch or hit a weak grounder. Strikeouts are happening at an alltime high rate, and sticky stuff may be one of the culprits. Major League Baseball has been contemplating what to do about all the reports of sticky fingers and as a result it announced in June that umpires will be periodically checking pitchers during games. Preliminary data released in early July showed that the prospect of increased enforcement of the rules against sticky stuff had already caused average spin rates to drop. But the cat-and-mouse game between players seeking enhanced performance and the league trying to catch them will no doubt continue, adding to the rich lore of cheating in baseball. —John Eric Goff

John Eric Goff is a professor of physics at the University of Lynchburg. This article is adapted from The Conversation (www.theconversation.com). Email: [email protected]

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Sightings

Giants in Traffic A data visualization quantifies the stresses that boats put on blue whales. lue whales are always on the go. These marine giants feed mostly on tiny krill, consuming 2 to 8 tons a day. “They need areas where krill congregate, to find big swarms for it to be profitable to engage in a dive,” explains Rodrigo Hucke-Gaete, a marine biologist at Universidad Austral de Chile and Centro Ballena Azul, a nongovernmental organization. About 20 years ago, Hucke-Gaete and his colleagues identified a particular area of Northern Chilean Patagonia as a rich feeding area for blue whales, and they have been working to get protected status for the area ever since. But the same area is also attractive for aquaculture, not to mention boats for fishing, tourism, and transport. The region is thus pretty congested, and whales are competing for space in which to move around. In a February 1 paper in Scientific Reports, the team showcased a new analysis of the whales’ predicament.

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The researchers used their whale data obtained from tags and visual surveys, and combined it with marine data (such as sea surface temperature, thermal fronts, and chlorophyll levels) of conditions favorable to krill. They overlaid vessel location data, which Chile requires fisheries, aquaculture, and transport boats to provide. The resulting maps showed the relative probability of a vessel encountering a blue whale (RPVEW); the map at right is specifically for aquaculture vessels, which make up 80 percent of the boat traffic in this area. But in addition to the maps, team member Luis Bedriñana-Romano created a data visualization of the life of one whale during one week. (Stills are below; see our website for video.) The animation (which does not depict the boats or whale to scale) demonstrates how much time and energy a whale (blue dot with streak showing movement) must expend avoiding

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aquaculture vessels (red dots with streaks showing movement). “It’s not only about the possibility of ship strikes, but exposure to noise, and just annoyance to the whales,” says Bedriñana-Romano. “If whales need to spend a lot of time trying to feed to get the energy required for migration, and they have to waste energy dodging boats all day, even if the boats don’t strike the whales, that’s a huge deal for a population that is recovering.“ Hucke-Gaete explains that whales don’t simply dive to avoid boats because whales travel at the surface when moving between feeding areas, which is faster and uses less energy. Also, krill go to the surface at night, so at dawn and dusk the whales feed there. “When you see a blue whale feeding at the surface, it’s like someone who hasn’t eaten for a week,” he says. “You don’t care what’s happening around you when you’re a 30-meter animal feeding on very small crustaceans.”

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The study has raised awareness about boat traffic and whales, says Bedriñana-Romano: “Chile has a lot of environmental issues, but traffic was not on the list so far, and in Chile there is no regulation on the speed of boats. It’s just the tip of the iceberg, but a concrete, specific thing that we can do now is requiring vessels navigating in a blue whale area to reduce speed.” The animation caused a stir on social media about the whale’s apparent stress. “We’ve gotten a lot of sympathy for what was happening to that whale,” says Hucke-Gaete. “Science needs to flow and to cross blockages that scientists ourselves sometimes provoke by talking about complicated stuff, and this video had so much impact.” The group next plans to incorporate more detailed data from international ships, satellites, and upgraded whale tags. The team is also looking to better quantify the migration routes and breeding grounds of the whales. “It’s very important that we now have the ability to congregate this kind of data, because the application for conservation is huge,” says BedriñanaRomano. “Data visualization is providing an aid that we didn’t have before. In terms of outreach or communicating something that is sensible for conservation, it’s the best, because it makes everything clear, you can reach everyone, and that’s cool.” —Fenella Saunders

Infographic | Corey S. Powell

The Wild Heart of the Milky Way “The center of our galaxy is complex, extreme, and violent,” says Daniel Wang of the University of Massachusetts, Amherst. To make sense of it, Wang combined radio imagery (purple-gray) from the MeerKAT observatory in South Africa with x-ray data (orange and blue-green) from the Chandra space telescope into an unprecedented panorama.

1. Sagittarius A* is the supermassive black hole at the heart of our galaxy, 4 million times as hefty as the Sun. It is calm compared with the black holes in many active galaxies, but it may have been much more active in the past.

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2. The Arches Cluster is the densest star cluster in the galaxy. Winds blowing from hot, newborn stars collide at high speeds here, creating the observed x-rays.

3. Bright blobs are x-ray

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4. Filaments are mysterious radio structures that trace the lines of the galactic magnetic field. At fine scales, they display complex structures, indicative of turbulent interstellar gas. The filaments may be energized by electrons from pulsars or supernova explosions.

5. G0.17-0.41 is a new kind of

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filament identified by Wang that is powered by magnetic reconnection—opposing magnetic fields that combine, releasing tremendous energy. It glows in both radio waves and x-rays (inset). The x-rays should fade in a century or so, leaving behind a long-lived radio filament. This structure is about 20 light-years long.

6. Plumes of hot gas flow from the galactic center. Over millions of years, such plumes may have blown out enormous lobe-shaped structures, called Fermi bubbles. 272

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X-ray: NASA/CXC/UMass/Q.D. Wang; Radio: NRF/SARAO/MeerKAT

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binaries: an ordinary star orbiting a dense neutron star or a black hole. Radiation from matter sucked in by the neutron star or the black hole reflects off intervening dust, producing a halo.

Briefings

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Medical engineers have created a nanoparticle that can help oncologists detect cancer through a simple urine test; the test can also identify the organs affected. The key to this development is a nanosensor that is delivered to a patient intravenously. As it passes through the body, the nanosensor reacts to proteases (enzymes that break down proteins) in malignant tumors, and biomarkers from that interaction are evident in the patient’s urine. The particle is attracted to the acidic environment common among cancerous tumors, and it contains radioactive copper-64, which shows up in positron emission tomography (PET) imaging. If a urine test indicates that the nanosensor has encountered cancer in the body, a subsequent PET scan can locate where the nanoparticles are collecting to pinpoint the tumor’s location. In mouse models, these tests successfully identified metastatic colon cancer and were able to track how the mice responded to chemotherapy treatments. This method would provide a less invasive way to diagnose cancer and could help with early detection of the disease.

Exoplanet Moon Creation

ALMA (ESO/NAOJ/NRAO)/Benisty et al.

For the first time, astronomers have found convincing evidence of a moon forming in a disc of dust around a newborn planet. Astronomers have theorized that moons originate in such discs, much as planets form in the larger discs around young stars, but nobody had seen the process in action. Researchers using the European Southern Observatory’s Very Large Telescope in Chile had previously detected two protoplanets (planets in the process of formation) in the PDS 70 star system, which is 370 light-years away and just 5 million years old—a stellar infant. Both protoplanets are gas giants several times more massive than Jupiter. A

team led by Myriam Benisty of the University of Grenoble used the Atacama Large Millimeter/submillimeter Array (ALMA, a collection of radio dishes in Chile) to zero in on the star system and found a dusty disc surrounding one of the protoplanets, PDS 70c; such a protoplanetary disc had never been observed clearly before. Some moons may have already begun forming around PDS 70c, but if so, they are too small for us to see. Observing the development of this young star system and its planets will help astronomers understand how our Solar System—in particular, the moon systems of Jupiter, Saturn, and Uranus—was formed. Benisty, M., et al. A circumplanetary disk around PDS70c. Astrophysical Journal Letters doi:10.3847/2041-8213/ac0f83 (July 22). www.americanscientist.org

Hao, L., et al. Microenvironment-triggered multimodal precision diagnostics. Nature Materials doi:10.1038/s41563-021 -01042-y (July 15).

Cooperative Plants An Australasian fern species may engage in division of labor in much the same way that some insects, such as ants and bees, separate tasks within their colonies. This type of division of labor by caste within a species is called eusociality. In addition to insects, it has been documented in crustaceans and two mole rat species, but until now the behavior had not been observed in plants. The fern, Platycerium bifurcatum, is an epiphyte, which means it grows on other plants but derives its nutrients from the air and rain (unlike a parasite, which draws nutrients from its host). Biologist Kevin Burns of Victoria University in New Zealand noticed that the plant grows in colonies of about 25 individuals and that they produce two types of fronds, which he calls strap fronds and nest fronds. The green strap fronds grow like long, thin leaves outward from the nest fronds, which are brown and anchored to the plant host. Burns and colleagues found that about 60 percent

of the strap fronds they studied were reproductively active, whereas the remaining strap fronds and all nest fronds were reproductively inactive; this division of reproductive labor is a hallmark of eusociality. The outer nest fronds are

CC-BY-SA 4.0/Krzysztof Ziarnek

Noninvasive Cancer Diagnosis

n this roundup, managing editor Stacey Lutkoski summarizes notable recent developments in scientific research, selected from reports compiled in the free electronic newsletter Sigma Xi SmartBrief: www.smartbrief.com/sigmaxi/index.jsp

large and waxy, and they shunt water to smaller, hydrophilic nest fronds in the interior. A root system then distributes the collected water throughout the colony. The identification of a eusocial plant challenges previous assumptions that this type of behavioral coordination requires a brain, and it raises the possibility of convergent evolution of that characteristic in plants and animals. Burns, K. C., I. Hutton, and L. Shepherd. Primitive eusociality in a land plant? Ecology doi:10.1002/ecy.3373 (May 14).

Reviving Pleistocene Life A multicellular organism that was trapped in permafrost for approximately 24,000 years is still alive. Lyubov Shmakova of the Soil Cryology Laboratory at the Pushchino Scientific Center for Biological Research in Russia and her colleagues thawed a bdelloid rotifer—a ubiquitous microscopic creature known to withstand extreme cold—from a sample collected in northeastern Siberia. The researchers radiocarbon-dated microbes that were frozen alongside the rotifer, which allowed them to estimate its age. Once it had been defrosted, the rotifer was able to reproduce asexually, which means that its DNA and other critical biomarkers remained intact after all those years. In 2018, another team successfully revived a 30,000-year-old nematode. These resilient multicellular organisms provide opportunities to study the biomechanics necessary to survive in low temperatures, which could lead to advances in cryobiology and biotechnology. Shmakova, L., et al. A living bdelloid rotifer from 24,000-year-old Arctic permafrost. Current Biology doi:10.1016/j.cub.2021.04 .077 (June 7). 2021

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Perspective

Tunnel Vision In outer space and within living cells, quantum mechanics allows molecules to take mind-bending journeys that would be impossible by the rules of classical physics. Dean J. Tantillo

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f you’re out for a stroll and reach a hill, the most obvious paths to the other side are over or around. But under the right set of circumstances—such as when there’s a convenient tunnel—sauntering through can be the simplest path forward. Chemical reactions must traverse hill-like barriers, too—in this case, energy penalties for reaching products. The path over requires enough energy to reach the hill’s peak or transition state. It takes a certain amount of energy, usually from heat, for a chemical reaction to happen. Normally, that allows the molecule to wiggle enough to climb over the energy hill. But the counterintuitive rules of quantum mechanics sometimes offer a tunnellike third option, so that the reaction can happen even without the added energy. Tunneling reactions are forbidden by classical reactivity rules, but by studying reaction rates, chemists can discover instances in which these prohibited reactions occur. That insight allows us to understand the nature of some biochemical reactions, the complex chemistry in interstellar clouds, and the practical chemistry of molecule synthesis. Because most reactions involve surmounting energy barriers the way hikers do when they climb over hills, reactions with lower barriers have faster rates than those with higher ones. But sometimes there isn’t enough energy available. For molecules, that means the barrier might be too high or tem-

peratures might be too cold. Alternative pathways can also be blocked or might not exist. Chemists have done many elegant experiments to show that reactions occur through tunneling and to determine how frequently molecules use this reaction path compared with over-thebarrier processes. Theoretical chemistry has been indispensable in interpreting the results of such laboratory experiments, because understanding tunneling requires quantum mechanics. Chemists map how reactions occur using diagrams that show both the heights of these hills (on the y-axis) and how much the molecule’s structure changes (x-axis). To understand how reactions happen, chemists mostly focus on the pathway over the hill. But quantum mechanics tells us that the width of the hill—the difference between the reactant and the product—matters, too, for tunneling to occur. Quantum mechanics comes in because molecules are small enough to be influenced by both their particle-like and wavelike properties. This characteristic is captured in the Heisenberg uncertainty principle, which states that one cannot accurately determine the momentum and position of a particle simultaneously. To account for quantum mechanical behavior, theoretical chemists express a particle’s position as a probability, which is related to the square of a socalled wave function. The Schrödinger

equation connects wave functions to molecules’ internal energies, allowing theoretical chemists to predict the energy-versus-structure curves you see in the diagram on page 276. This is where our hill climber/ molecule analogy begins to break down. In the example on page 276, there is a very small but greater than zero percent chance that a reactant molecule has a product-like structure, because the tail of the wave function resides in the product region. And the narrower the hill, the greater that possibility is. When tunneling occurs, no actual hole has opened in the hill, but rather the hill does not eradicate the probability that the reactant is just the product. By contrast, in the macroscopic world, there is no chance that a human climber, when standing in front of the hill, could be inside the hill or on its far side. That’s because people don’t behave much like waves. Tunneling is always one possible reaction path, but it’s an unlikely one when temperatures are high and molecular hills are relatively easy to climb. But at very low temperatures, such as those close to absolute zero, any reactions that occur must result from tunneling. Tunneling is also more likely under circumstances where a chemical reaction produces a small structural change, which means the reaction has a narrow barrier—such as the movement of a single small atom within a large, complex molecule.

QUICK TAKE In tunneling reactions, molecules follow quantum mechanical rules rather than classical ones to travel through energy barriers rather than climbing over them.

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Molecules use heat energy to vibrate, which allows them to travel over energy barriers. Therefore, tunneling reactions are more likely to dominate under extremely cold conditions.

Tunneling probability increases for reactions that involve small structural changes, such as moving a tiny hydrogen atom within a large complex molecule.

Courtesy of Alexey Sergeev

Most chemical reactions require a molecule to climb an energy hill to transform into a product. But quantum mechanics provides another option, through a process called tunneling, which is a bit like the tunneling done through actual hills that are difficult to scale, such as Gull Rock Tunnel (pictured here) in Newport, Rhode Island.

Outer Space Outer space, where baseline temperatures hover below −270 degrees Celsius, is so cold that molecules can barely vibrate. With almost no thermal energy available to propel chemical reactions over traditional barriers, most reactions can’t occur under classical conditions. But despite frigid temperatures, many chemical reactions do occur in space. And laboratory experiments suggest that tunneling plays a key role in determining which chemical reactions predominate in giant interstellar clouds of gas and dust. Dwayne Heard and his coworkers from the University of Leeds wanted to understand more about which reactions occur and why within dense molecular clouds, which are hydrogen-rich clouds, up to hundreds of light-years wide, where new stars can form. For example, hydroxyl radical (HO•) can steal a hydrogen atom from methanol (HOCH3) to form water via tunneling. Under space-like laboratory conditions (very low temperatures), the team www.americanscientist.org

observed a reaction rate that was much faster than expected for an over-thebarrier reaction in such extreme cold, leaving tunneling as the only viable option. Radio telescopes have observed these molecules, offering evidence that tunneling shapes astrochemistry. Interstellar chemistry is wonderfully complex and produces complex organic molecules that we associate with life. Another unusual interstellar organic molecule is CH5+, which has challenged the very notions of molecular structure because, unlike most molecules, its geometry can’t be pinned down. This molecule seems to violate a cardinal rule of earthbound organic chemistry— that a carbon atom can only make up to four bonds at a time. But the real constraint is not four atoms bonded to carbon but the total number of electrons involved: no more than eight. CH5+ includes three two-electron covalent bonds within a CH3+ unit, but that group interacts with an H2 unit that brings two more electrons to the party. Those two electrons are shared

among the two hydrogen atoms and the carbon atom in a three-center, twoelectron bonding array. In addition, the five hydrogen atoms of CH5+ constantly scramble their bonding roles, interconverting between two-center and threecenter arrangements. This constant shifting involves swapping equivalent structures and uses tunneling, too. Inner Space In the frigid depths of space with almost no thermal energy, it’s clear why reactions might predominantly occur via tunneling: Often, there simply is no other way over the energy barrier. But tunneling is also a significant factor in much warmer environs, such as living cells, where tunneling pathways facilitate important biochemical reactions. In these situations, molecules are taking advantage of the small change in structure between the reactant and product. In such situations, the width of the reaction barrier is narrow, which makes passing through easier. For decades, chemist Judith Klinman of the University of California, Berkeley, and her coworkers have used a range of elegant experiments to show how tunneling pathways can contribute to the overall rates of some hydrogen transfer 2021

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reactant wave function

energy barrier

tail of wave function in product region

lower barrier

relative energy

relative energy

transition state structure

reactant structure product favored by over-the-barrier reaction

Chemists use these types of diagrams to map how reactions occur. Most often, a molecule follows the classical pathway (black line), taking advantage of heat energy to vibrate over the energy barrier (red arrow). Quantum mechanics provides an alternative, competitive route (green line). The bell-shaped curve shows the range of probable structures that can exist. When the red barrier is high and the width of the barrier is thin, the range of probable structures can span from reactant to product.

reactions—frequent, important, and subtle reactions that shuttle these smallest atoms from one carbon atom to a near neighbor—facilitated by enzymes. These types of reactions are involved in metabolism, for example converting fats into oxygenated molecules involved in cell-to-cell signaling. Estimates of how often tunneling occurs in biology vary widely. Some chemists think enzymatic tunneling is a rare phenomenon. But in a 2018 article in Chemistry World, Klinman estimated that up to a third of enzyme-promoted hydrogen transfers occur via tunneling. After all these years, we are still learning how much of our own life processes depend on the subtleties of quantum mechanics. A key tool for studying and understanding these tunneling pathways is the kinetic isotope effect approach. (For a detailed dive into kinetic isotope effects, see "Hacking Hydrogen," January–February 2020.) Chemists can replace a critical atom in a molecule with a heavier isotope, such as trading a hydrogen atom for its twice-as-heavy isotope, deuterium. If a reaction pathway involves traversing a traditional energy hill through a transition state, the deuterium transfer can be up to a factor of 10 slower than a hydrogen transfer because of its greater mass. However, with some enzymecatalyzed reactions that involve hydro-

product favored by tunneling

structural change during reaction (reaction coordinate)

structural change during reaction (reaction coordinate)

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higher probability of forming product via tunneling

reactant

product structure

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In this more complex diagram, a chemical reaction can lead to two different products depending on reaction conditions. Traditionally, chemists have predicted which product is preferred based on the energy barriers (red arrows) or the energy of the products (location of the black curve’s troughs). But tunneling (green line) can also help determine which product forms. Chemists can change reaction conditions to favor or restrict tunneling and thus influence which reaction occurs.

gen transfer, swapping in deuterium can slow reactions down far more than that—by a factor of nearly 100 in some cases, based on Klinman’s work. Tunneling can explain these extreme slowing effects. Deuterium’s greater mass lowers the energy of its vibrational states compared with those of hydrogen. Reacting

Tunneling is always one possible reaction path, but it’s an unlikely one when temperatures are high and molecular hills are relatively easy to climb. via a lower vibrational state means facing a lower part of the barrier, and the barrier is always wider where it is lower. Consequently, tunneling with a deuterium atom is much more difficult than tunneling with a hydrogen atom.

Many of Klinman’s studies of tunneling in enzymes have been done by studying kinetic isotope effects in a common family of enzymes known as lipoxygenases. These enzymes are found in organisms ranging from protists and fungi to animals, including humans, and these enzymes can show very large kinetic isotope effects. Lipoxygenases add oxygen atoms to polyunsaturated fatty acids, opening up pathways for these molecules to fragment into smaller ones. These enzymes are important in cell signaling and are linked with some cancers, cardiovascular disease, inflammation, and metabolic diseases. Some lipoxygenases are also used commercially, in fragrance production for instance. Although tunneling has been documented most thoroughly in reactions that involve making and breaking bonds to hydrogens, thin-barrier reactions— those in which bonds are made to and broken from heavier atoms—can also occur via tunneling. For example, molecules with systems of alternating short and long carbon–carbon bonds can undergo a reaction that exchanges their bonding patterns. Because the lengths of the short and long bonds are often only 10 percent different, the barriers between reactants and products are thin, which makes tunneling viable. This area of research is ongoing, and chemists

NASA, ESA, M. Robberto (Space Telescope Science Institute/ESA) and the Hubble Space Telescope Orion Treasury Project Team Protein Data Bank/Scouras, A.D., Carr, C.A.M., Hu, S., Klinman, J.P.

In interstellar clouds such as the Orion Nebula, interesting chemical reactions take place but there is little thermal energy to fuel them. Tunneling provides an avenue for these reactions to occur even at the very low temperatures found in interstellar space.

Chemist Judith Klinman and her colleagues have studied tunneling extensively in the pictured enzyme, soybean lipoxygenase. Their studies of reaction rates show that the enzyme takes advantage of tunneling to transfer hydrogen atoms, and Klinman estimates that this process occurs in many other similar enzyme-catalyzed reactions.

have described examples of so-called heavy-atom tunneling that involve oxygen, nitrogen, and fluorine atoms, too. Tuning In to Tunneling The vast majority of chemical reactions have rates that are not dominated by tunneling, but tunneling always contributes, at least a little bit. But in the past, most chemists only considered the effects of tunneling when they enwww.americanscientist.org

countered unexpected results. That approach can get one pretty far, but such blinders can lead to missed opportunities, particularly for reactions in which changing conditions such as temperature or the time of reaction can change the mix of products. For example, within the past several years Peter Schreiner from Justus Liebig University Giessen in Germany and his colleagues have shown that one can design reactions in which particular products can be selected for by tunneling. Up to this point, we haven’t considered situations in which a single reactant can travel two wildly different chemical pathways to distinct products (see facing page, diagram on right). In some cases, the barrier to one product is comparatively low but wide, whereas the barrier to the other product is high but thin. In such a scenario, the preferred product will depend on whether tunneling dominates. At relatively high temperatures, energy barriers can be surmounted, so the reaction with the lower barrier will be preferred. But when temperatures are too low to surmount the barriers, products will be formed by tunneling through barriers. Under those conditions, the pathway with the thinner barrier—a smaller structural difference between reactant and product—will prevail. So, by controlling the temperature, one can select for either product. Schreiner and his colleagues have shown that when chemists understand both the relative “heights” and “widths”

of barriers, they can use that information to steer reactions toward the products they want, and exclude others, based on differences in tunneling contributions. Until recently, synthetic chemists generally exerted this control by considering the relative height of the barriers—how fast the products form—or the energies of the molecules at the end point of each pathway, the relative stability. Schreiner’s work adds tunneling as a third factor to consider, a so-called third paradigm of selectivity control. The doors have now been thrown open, and many chemists will no doubt walk through them to design new chemical processes. Some researchers are refining models of tunneling to better capture the fundamental physics involved, whereas others are applying the working models of tunneling to problems in reaction design. Quantum chemical phenomena steer many important chemical reactions—ones that are occurring in you, in the organisms and atmosphere that touch and surround you, and in exotic realms lightyears above your head. Something to think about while out for a stroll. Bibliography Castro, C., and W. L. Karney. 2020. Heavyatom tunneling in organic reactions. Angewandte Chemie International Edition 59:8355–8366. Klinman, J. P., and A. R. Offenbacher. 2018. Understanding biological hydrogen transfer through the lens of temperature dependent kinetic isotope effects. Accounts of Chemical Research 51:1966–1974. McMahon, R. J. 2003. Chemical reactions involving quantum tunneling. Science 299:833–834. Schreiner, P. R. 2020. Quantum mechanical tunneling is essential to understanding chemical reactivity. Trends in Chemistry 2:980–989. Shannon, R. J., M. A. Blitz, A. Goddard, and D. E. Heard. 2013. Accelerated chemistry in the reaction between the hydroxyl radical and methanol at interstellar temperatures facilitated by tunnelling. Nature Chemistry 5:745–749.

Dean J. Tantillo loves to study the complexity associated with his young children and with the mechanisms of chemical reactions. He does both in Northern California, as a professor of chemistry at the University of California, Davis. Email: [email protected] 2021

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Engineering

What Lessons Will Be Learned from the Florida Condo Collapse? The deadly catastrophic failure has put a lens on building maintenance. Henry Petroski

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he condominium complex known as Champlain Towers is located in the town of Surfside, Florida, just north of Miami Beach and about 10 miles northnortheast of downtown Miami. Until recently, it consisted of three 12-story buildings containing collectively a total of 342 apartments, ranging in size from one to four bedrooms. The building designated Champlain Towers South occupied prime oceanfront real estate and contained 135 condo apartments. In the very early hours of June 24, 2021, a wing of the Towers South building, which contained 55 condos, collapsed suddenly into a pile of rubble. Virtually all of the occupants, most of whom were presumably asleep at the time, were crushed to death. Exactly how many victims there were remained uncertain for weeks, because there existed no accounting of which residents had been at home or what guests might have been staying over at the time. The confirmed death toll rose slowly as bodies were recovered from the pancaked floors. For a while, it looked as though the death toll might surpass that in the 1981 collapse of elevated walkways in the Kansas City Hyatt Regency Hotel, whose 114 victims had marked the most lost in any American structural failure. But at the time of this writing, the Surfside death toll stands at 98. The search-and-rescue operations that began within hours of the condo collapse had to proceed slowly, lest the pile of broken and crushed concrete and exposed and twisted reinforcing steel become un-

Henry Petroski is the Distinguished Professor Emeritus of Civil Engineering at Duke University. Email: [email protected] 278

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stable and do further harm to any survivors buried within it. There was also concern that the part of the building that remained standing could fall at any time and harm the rescuers. To minimize this risk, the remaining structure was monitored carefully for any movement that would signal imminent collapse. In the meantime, Tropical Storm Elsa had developed in the Atlantic and was threatening to strike south Florida with high winds, which could trigger another collapse. To obviate further disaster, Surfside, Miami-Dade County, and other government officials, in consultation with engineers, decided to demolish the section of the building that loomed over the pile of rubble. Demolition experts assured the decision makers that careful placement and detonation of explosives could bring the building down in a controlled manner so that it would fall away from the area of active search-andrescue operations. The demolition on the evening of July 4th, 11 days after the initial building collapse, went exactly as planned, and the search for human remains resumed within hours. Condo Rules Champlain Towers South was only one among a seemingly countless number of high-rise condominium buildings in the area, almost all of which are no more than 40 or 50 years old. Individual ownership of apartments in multiunit buildings in the United States was encouraged by the National Housing Act of 1961 and quickly endorsed by every U.S. state. This act led to a building boom during the 1970s and 1980s, when condominium and co-op apartment units were built (or converted) at a rate of 100,000 per year. Today, more than

10 million Americans—1.5 million in Florida alone—live in such units. Governance—including matters of local code compliance, capital improvements, and repairs—is overseen mainly by owner associations, whose representatives usually have little or no experience in operating and maintaining a large structure. Champlain Towers South was built in 1981, and as such was subject to a Miami-Dade County requirement that it had to be recertified when it reached 40 years of age. The rule was established in the wake of the collapse in 1974 of a federal building in downtown Miami. An investigation traced that spontaneous failure to the presence of chemical salts in the concrete, which accelerated corrosion in the reinforcing steel known as rebar. The pervasive hot and humid seaside environment in which Champlain Towers South sat for decades was also not favorable to the rebar that had been used to tie its floor slabs to columns and form the building’s structural skeleton. As the recertification deadline was approaching, the Champlain condo board engaged consulting engineer Frank Morabito, of Maryland-based familyrun Morabito Consultants, to evaluate the building’s structure. According to a July 5 Washington Post article, professionals familiar with Morabito’s work describe him as “careful and thorough.” In his 2018 report to the board, Morabito described finding, among other problems, “major structural damage” in the concrete slab that formed the pool deck and the columns that supported it. Furthermore, because this slab was perfectly horizontal, water did not drain properly, thus affecting the waterproofing and further aggravating the corrosion problem. Morabito’s estimate that it would cost

Gerald Herbert/AP Images

Champlain Towers South was one of the many high-rise apartment buildings that line the coast of the Atlantic Ocean in Surfside, Florida. At about 1:30 a.m. on June 24, 2021, a large part of the condominium collapsed suddenly, burying 98 occupants beneath a pile of rubble. Many theories have been proposed to explain the massive structural failure, but a final determination of the cause of the collapse will not be arrived at for some time.

$9 million to correct the problems understandably shocked the condo board. Deciding what to do was complicated by the fact that Morabito’s recommendation that the repairs be done “in a timely manner” was contradicted by a separate assessment in November 2018 from Surfside’s chief building official, who assured Champlain Towers South owners their building was “in very good shape.” During two years of haggling, progress was made only in the deterioration of the structure, and the estimated cost of repairs needed to deal with corrosion, waterproofing, and drainage problems rose by several million dollars. Owners of larger units in the building were facing a six-figure special reassessment. When there finally was agreement that the work had to be done, and done urgently, the condo association engaged Morabito as supervising engineer to prepare the necessary documents relating to the repairs, to help select a contractor, and to monitor the work. Shortly before the collapse, repair work had begun on the roof; shortly after the collapse, lawsuits were filed claiming that Morabito, the condo association, and city building officials should have warned owners that the building was in danger of falling down. www.americanscientist.org

Answers in the Rubble As is the case following any structural failure, there arose—in Surfside, seemingly even before the concrete dust had settled—the question of what caused the tragedy. Everyone—condo owners, victims’ families, government officials, regulators, members of the news media, lawyers—wondered exactly what caused the condo wing to collapse and who was to blame. The rubble was expected to hold physical clues, and paper documents—in the files of architects, engineers, contractors, inspectors, and others who had a hand in the construction and maintenance of the building—promised to provide intellectual clues to help interpret the physical ones. Such documents include construction contracts, design calculations, blueprints, and related correspondence among the parties involved. Parties whose culpability might be implicated in such papers are not always forthcoming with them, but pressure from the news media can often force their release, if not voluntarily then by order of the courts. The State of Florida has especially strong “sunshine laws” that require the release of many such documents to the public.

Newspapers such as the Miami Herald and New York Times, with reputations for doing in-depth investigative reporting, can be counted on to disseminate thoroughly and quickly as much information about a tragedy as they can find. But a news story about a failure with implications for construction around the world conveys more credibility when it quotes authoritative experts. A story about a building collapse that quotes only unnamed experts can be as suspect in its completeness and reliability as a political story that relies solely on anonymous sources. Although engineers in general have a reputation for not seeking to aggrandize themselves, most are not shy about opining about a topic that falls within their specialty. Structural engineers are naturally the most obvious choices to interview for background on and interpretation of any type of structural failure. However, codes of ethics caution engineers not to comment on projects with which they are not familiar. This mandate keeps some engineers from commenting altogether. But many whose expertise is so closely related to the circumstances of a particular recent failure do feel comfortable likening it to historical examples and elaborating on their causes. They may also feel qualified to hypothesize about what appears to be an analogous failure. And these engineers attest to their confidence in their speculations and interpretations by 2021

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Town of Surfside Public Records

Part of the building collapse was captured by a surveillance camera, which provided professional and amateur engineers alike with evidence of how the failure proceeded. In this drawing, the footprint of the intact building is outlined. The color overlays indicate sections of the building that appear in the video to have fallen in sequence (red, orange, green, blue), and the subsequent debris fields, but the exact details and root cause of the failure remain open to discussion.

their willingness to be quoted by name in newspaper and magazine articles, which are the sources of the following. One engineer who was willing to be named is Glenn Bell, a retired senior principal and former chief executive officer of the Waltham, Massachusetts– based consulting firm Simpson, Gumpertz & Heger, which has a strong reputation in failure analysis. Bell is a former president of the Structural Engineering Institute of the American Society of Civil Engineers and is currently a director of Collaborative Reporting for Safer Structures US, which is modeled after a successful program established in the United Kingdom. In the immediate wake of the condo collapse, Bell cautioned engineers “not to speculate too much on the potential causes.” He noted that “most catastrophic collapses happen either during construction or early in the life of the structure, indicating there were systemic, inherent structural problems.” The fact that the Champlain tower stood for 40 years strongly suggests that something else may have caused it to fall. Bell, who was involved in the investigation of the Hyatt Regency walkways collapse, is a proponent of putting forth testable hypotheses by imagining “a video of the structure collapsing in a certain sequence that’s along a certain failure hypothesis that you have” and asking, “Would it wind up in a pile that you’re 280

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seeing on the ground here? Or is that pile not consistent with your theory?” If not, a different theory must be found. To Bell, a pile of debris such as that on the Champlain Towers site is evidence to be sifted through for clues that could help confirm or refute a working hypothesis. According to Bell, forensic engineers like to say that “to the trained eye, the structure will talk to you.”

The building likely did not collapse for one reason. Often three or four things have to happen for a collapse to occur that is so catastrophic. One thing that was clear to Bell was that “the investigation will take time.” This familiar sentiment of experienced forensic engineers was echoed by Roberto Leon, a professor of construction engineering at Virginia Tech, who the day after the collapse also stated the familiar thought that “it is way too early to tell” what caused the failure. He did not think “the building collapsed just because of one reason. What we tend to find in forensic investigations is that

three or four things have to happen for a collapse to occur that is so catastrophic.” In the days following the tragedy, the views and theories of structural engineers named and unnamed were quoted both directly and indirectly in news media of all kinds. A comprehensive article on the Surfside condo failure appeared on June 28 in Engineering News-Record, a construction industry magazine with a long and distinguished history of reporting on failures, and quoted 80-yearold Allyn Kilsheimer, founder of the Washington, D.C., firm KCE Structural Engineers, whose experience includes involvement in structural investigations following the September 11, 2001, terrorist attacks on the Twin Towers of the World Trade Center. He was retained by the City of Surfside to investigate the condo collapse. In talking about it on the record, he was careful not to speculate on a failure regarding which “there are lots of questions.” He acknowledged the helpfulness of video from a surveillance camera mounted nearby that captured all but the first few seconds of the event as it occurred, but he laments that the recording did not begin the moment the collapse began and provides only a single point of view. He expressed the hope that other videos might emerge to allow engineers to gain a three-dimensional understanding of the exact manner in which the building fell. As the collapse occurred in the early morning hours, it was not likely that anyone was standing on a nearby balcony with a video camera running. However, one resident did report that just before the catastrophe, she saw that “a section of the pool deck and a streetlevel parking area had collapsed into the parking garage below.” (She had left her apartment to complain about the noise, and so survived the subsequent collapse.) A later victim, Cassie Stratton, who was looking out the window of her fourth-floor apartment while talking on the phone with her husband, described to him what she was seeing in real time. According to a June 27 story in the New York Times, he reported her saying she saw “a hole of sorts opening near the pool” before the call was dropped. Indeed, on July 5 the Times published photographs and diagrams showing the pool deck, complete with vehicles that had been parked on it, lying atop the basement floor. It had clearly fallen almost intact, leaving the columns by which it had been supported now poking through it. These images were strong

evidence of what is termed a punching shear failure, and it is usually attributed to insufficient reinforcing steel having been used to connect a concrete slab to its supporting columns. A close-up photo of one column showed bent strands of rebar emanating from it as if the slab had pulled away from the rebar as it fell. Engineers who compared these strands with design drawings strongly suspected that a less-than-adequate quantity of reinforcing steel had been used in the column-floor system. Closer inspection under controlled conditions of samples of the concrete, steel, and subassemblies retrieved from the wreckage should confirm or refute such an interpretation. But even if confirmed, this evidence alone would not rule out other factors having played a role in the overall failure. Many Theories Once experienced engineers have access to design and construction documents, including building plans, they can test their theories and more reliably imagine how a structure might fail. But just as a person whose only tool is a hammer sees every problem as a nail, so an engineer’s area of specialization can narrow his or her focus to look within it for failure scenarios. Structures are, of course, built from the bottom up. The need to build on a firm foundation is, indeed, a virtual cliché. The nature of the ground on which Champlain Tower South was founded naturally became one place to look for a culprit. Sandy beachfronts do not make for good foundations, and so to build tall beside the ocean requires digging down into the underlying ground to reach some solid resistance. If it can’t be found, then an array of long columns or piles can be cast or driven into the sand until the resistance encountered in driving them further down is considered sufficient to support a structure of considerable weight, such as one of the Champlain Towers or its neighboring high rises along the beachfront. If a foundation is not firm, whatever rests upon it can sink or settle over time. If such subsidence occurs slowly and uniformly, it may only amount to the inconvenience of having to alter the transition from sidewalk to building from time to time. According to Shimon Wdowinski of the earth and environment department of Florida International University, Champlain Towers South was sinking in the late 1990s by about 2 millimeters per year, or about a centimeter www.americanscientist.org

Miami-Dade Fire Rescue

Clues as to what may have triggered the collapse and how it proceeded have been found in the rubble. Engineers have focused on such details as the column numbered 72 in this photo, taken before a controlled demolition of the remaining structure. The photo strongly suggests that this section of parking deck, along with the vehicles on it, fell intact onto the floor of the underground parking garage. The bent and twisted steel reinforcing rods sticking out of the damaged column (red circle) are evidence that so-called punching shear was the mode of failure at this location.

over five years. Had such settlement been other than uniform, cracks would have been expected to open up in the building’s floors and walls. Although one condo owner did complain about rain entering her unit through a cracked outside wall, there did not appear to be widespread cracking in the condo units. Engineering News-Record on July 5 credited an unnamed engineer with imagining that a sinkhole may have opened up beneath the building, allowing one or more concrete piles to drop into the hole and so cease to carry their share of the load, thereby initiating the progressive collapse of the entire building. Another theory was put forth by the founder and president of S. K. Ghosh Associates, a Chicago-area consulting firm with expertise in building codes and the seismic behavior of structures. Although there was no suspicion that the Surfside collapse had anything to do with an earthquake, an engineer such as Ghosh could imagine that if a sizable portion of the concrete deck slab fell virtually intact onto the floor slab of the underground parking garage, the impact might have sent out a shock wave that could have broken some weakened columns, which in turn would overload nearby columns and cause them to fail, leading to a progressive collapse of the entire structure. The reinforced-concrete building was located just 100 yards from the ocean,

which provided the kind of salty and humid environment that is highly corrosive to steel. However, as long as the concrete protected the steel reinforcing bars from the moist air, the structure should have performed as designed. But concrete is prone to cracking, which can expose its rebar to the elements. When this happens, the steel begins to corrode and the accumulating rust expands against the concrete, which causes it to crack more, and chunks of it fall off, in a process known as spalling. This process is well known, and if allowed to proceed unchecked, it can be responsible for bringing a whole structure down. Morabito appears to have observed such damage. At the time this issue is going to press, it is too early to tell with full certainty which of the many theories proffered is the most probable. It is unlikely that any one of them alone will fully explain what actually happened. Jack Moehle, a professor at the University of California, Berkeley, a school with a historically strong structural engineering program, has said of the collapse, “It will be a long time before this has been thoroughly studied and thoughtfully considered.” Only after that has happened will engineers be able to draw definitive conclusions about the collapse’s most probable cause and to outline the lessons that may be learned from the tragedy. (References are available online.) 2021

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Arts Lab

Etching the Landscapes Within Visual depictions of healing can encourage positive change. Kim Moss

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esiliency. If 2020 has tested anything, it is how well we can stand up to hard times. Of course, as we look forward, we will continue to navigate how to bounce back from recent and new challenges. Our health and well-being are enfolded into the concept of resiliency, and I believe that being resilient requires mental fortitude in combination with a strong physical base. This mind–body connection is something that informs my art practice and is the basis for my installation, The Landscapes Within. Although I created the work before the pandemic, COVID-19 has given me reason to refocus on this theme. I have been reminded of how our actions and outlook, in conjunction with quiet time for contemplation, can help us face difficulties. The work, comprising three stacked series of hand-etched glass panels (approximately 0.5 meter by 1 meter each), addresses resilience and plasticity in the body—a theme of damage and repair. Frequently, we aren’t aware of the agents that attack us because our defenses work well. With knowledge of these incredible internal defenses and repair processes, we can augment and connect their efficacy to our actions and lifestyle habits. We can bolster our own resiliency and empower positive change. Therefore, the three pieces in The Landscapes Within highlight different examples of how the body responds to health issues in positive ways when coupled with beneficial lifestyle choices. The first panel series, The Innate Immune Response, shows alveolar macrophages, or white blood cells of the lungs, fighting against inhaled infectious agents (see page 286). These industrious cells, which are part of the defense system we are born with, often go un282

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noticed as they protect us around the clock. Sometimes, however, these “do good” cells are also part of the complications of disease. They have been tied to issues of a hyperresponsive immune system. Additionally, pollutants such as tobacco smoke, ozone, and aerosols diminish the power of alveolar macrophages to engulf and destroy unwanted elements. Understanding how these cells respond to infection and the reversibility of their positive and negative responses can help viewers re-

Visualizing microscopic processes points to the interconnected systems at work, as though they are an ecosystem in the body. flect on their own ability to support this defense system through actions such as mask wearing and promoting clean air. The second panel series, Cells in Transition, conveys the plasticity of the cells lining the esophagus (see facing page). Esophageal cells form one type of epithelial tissue, which lines the surfaces of our bodies. These lining tissues include layers that specialize in response and repair. Acid reflux is a common condition and presents as the well-known symptom of heartburn. Time and again, the esophagus recovers from damage caused by gastric acid that splashes up above the diaphragm into the esophagus. If acid reflux becomes chronic, however, normal cells can transition to abnormal metaplastic cells, which can be a precursor to esophageal cancer.

In this piece, the panels show normal esophageal cells, gastric acid, and abnormal tissue. The piece can be viewed both ways through the glass, showing the layering from normal to abnormal or the opposite. This design reflects the reversibility of negative effects; abnormal cells can differentiate to normal again. Regular monitoring of the esophagus and healthy lifestyle choices, such as a good diet and avoiding overeating and smoking, bolsters this tissue’s response to damage, and healthy tissue can be restored. It is my hope that viewers will look at these panels and consider how resilient these tissues are and how it’s often not too late for people to engage in healthy lifestyle choices that will make a difference in their lives. The hippocampus, a critical structure found within the human brain’s temporal lobe, is the topic of the third panel series, Response to Stimulus (see page 285). This part of the brain is connected to learning, memory, and emotion. Prolonged stress, as in post-traumatic stress disorder (PTSD), has been shown to damage the hippocampus and affect memory retention. My work invites viewers to consider how their own positive actions can support hippocampus function. Research suggests that exercise and positive affirmation can counter damage to the hippocampus and improve memory. A positive outlook can enhance clear thinking and promote curiosity and problemsolving. The hippocampus is also an area researchers are investigating for adult neurogenesis—the ability to Layers of glass etchings set aglow with colored lights celebrate the body’s resilience in Cells in Transition, and in other works from the author’s art installation The Landscapes Within.

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In the The Landscapes Within, viewers can approach each piece from many directions (below) in a contemplative space that the author hopes will spark curiosity and self-reflection (above).

generate neurons later in life, improving cognitive function. Stem cells representing this potential are shown as structures imbedded in a diverse array of neuron types within the curved etched area in the panels. The density of cells and the colors in this work do not come close to capturing the real density and complexity of cells within the brain, but it is my hope that the viewer starts to see how this network enhances the brain’s resilience. Each of the three pieces in this installation is composed of multiple glass

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panels stacked vertically to convey cellular elements in a three-dimensional space, or layers and depth of overlapping tissues. The works are illuminated by colored lights at the perimeter, which are refracted at different angles and change as the viewer moves across and around the piece, creating a dynamic and shifting effect. The colors and light quality also look different depending on the light quality of the room. I wanted these panel series to counter the anxiety that often accompanies complex or negative topics. For me,

making sense of complex health issues like the COVID-19 pandemic requires picturing the problem. Visualizing microscopic processes points to the interconnected systems at work, as though they are an ecosystem in the body. I want to draw out the innate systems of defense that we rely on daily and visualize the key characters at work. I am also now researching how to create a similar etched panel on coronaviruses and vaccines that might distill some of the complex science behind the disease and offer a nonconfrontational way for viewers to consider the efficacy of vaccination. With all of my etched glass works, I aim to engage viewers in learning and

introspection from a backdoor approach. The key mechanism here is to spark curiosity and draw viewers into topics concerning their health and wellness, uninhibited and with an open mind. The framework for this experience is best when it includes an environment that is devoid of distractions and encourages slowing down, or slow learning. I am interested in creating an immersive experience that provides a medium for self-reflection, contemplation, honest assessment, and an open format for flexible thinking and decision-making. With this approach, rather than a clear didactic presentation, it is okay if some viewers struggle at first with what the content is or means. s a biomedical artist, I work in many art forms. I am trained as a medical illustrator, which entails translating and communicating medical content visually through media such as textbook illustrations, animations, interactive web content, augmented and virtual reality, instructional design, and more. I also work as a scientific illustrator, depicting an array of bo-

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tanical, entomological, and other scientific content. I often feature micro-macro connections in the environment, or the fascinating complexity of a particular organism. Some of my work is didactic with a very specific intention to inform the viewer, whereas other pieces are more open to interpretation. I also have a background in fine art, and love to explore the ways different disciplines and types of visual work intersect to reap unique depictions, new ways of understanding, and unexpected benefits. For example, in another body of work called Backbone Unearthed, I blend cartography, fine art, and science illustration to connect the macro and micro elements of Iowa’s Backbone State Park. The result simulated my experience of walking in the park—how I could get a sense of the

topography while looking closely at the small organisms at foot level. In creating The Landscapes Within, I drew upon a visual and scientific theme that never fails to fascinate and resonate with me: “Form fits function.” I am captivated by processes within the human body that serve as models of resiliency, and sometimes even reversibility. As I consider cellular mechanisms, the forms make sense and provide a stimulating springboard for creating art, both abstract and representational. When viewed on a microscopic level, individual cells are visually striking, presenting a diversity of forms, and tissue layers resemble a dynamic landscape. Many biological processes are mechanisms of healing and disease that are tied to how we engage in self-care,

Response to Stimulus depicts the hippocampus, a region of the brain that can be damaged by prolonged stress, affecting memory. The author aims to draw attention to how exercise and positive affirmation can counter that effect. In the detail (right), excitatory neurons, which promote signal transmission, are prominent. In a view of the panel’s reverse side (below), astrocytes—which help in memory formation—and stem cells are more visible.

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In The Innate Immune Response, white blood cells in the lungs use tentacle-like projections to engulf bacteria, pollen, and other foreign bodies. By helping viewers better understand these cells that protect us daily, the author wants to inspire positive changes such as mask wearing and promoting clean air.

decision-making, treatment plans, and a positive outlook. Resiliency is premised on connecting what we do on the outside to microscopic functionality on the inside. My attention to understanding disease processes and treatments snapped into focus a decade ago when my father was diagnosed with esophageal cancer. I understood that navigating his treatment and recovery would require personal health literacy, which the Centers for Disease Control and Prevention defines as “the degree to which individuals have the ability to find, understand, and use information and services to inform health-related decisions 286

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and actions for themselves and others.” Trained as a medical illustrator, I knew how to delve into treatment options and research on the disease. Yet I found I was not immune to challenges of health literacy; cycles of concern interrupted my focus and made it hard for me to help my father. I also discovered that I longed for visual material that went beyond literal illustrations of biological structures—art that encouraged self-reflection or a quiet contemplation of the complexity of the matters affecting and related to disease and healing. I created The Landscapes Within to develop this visual space for self-reflection and to test a new type of art that could

help others wrestling with their own health-literacy issues. It’s difficult, even terrifying, to process information about life-threatening disease. It is common to have heightened anxiety, and to not fully process what is going on because it is happening within our bodies at a level we cannot see with the naked eye. In other words, stress about our health affects our health literacy, our ability to heal, and our resilience. For some people, confronting information on complex issues and challenges shifts them into a problemsolving mode. They become focused on information gathering, analysis, decision-making, and strategic thinking. For others, the same issues and information initiate a closed circuit of worry. Upon hearing bad news, they plunge into a vortex of questions, concerns, and hypothetical outcomes—a process that overshadows the ability to make sense of a situation in difficult times. This response can inhibit flexible thinking and the ability to identify a pathway to viable solutions.

Art can play a productive role in the above scenarios. But various types of artwork could inhibit or promote either response. For example, approaching a realistic surgical illustration versus a less literal artwork may elicit different frames of mind in different people depending on how anxious it makes one feel. But the renowned work of engineer and psychologist

Stress about our health affects our health literacy, our ability to heal, and our resilience. Don Norman has shown that being attracted to something we find aesthetically pleasing promotes a positive mindset and opens the door to comprehension. It is my hope that viewers are drawn to The Landscapes Within because it piques their curiosity and leads to positive change while reducing anxiety. For all these reasons, it was important to me that The Landscapes Within be in a public setting and accessible. I appreciate the feedback I have received thus far from presenting the work in museums such as the Science Center of Iowa, and I greatly valued its inclusion www.americanscientist.org

From this angle, Cells in Transition shows normal esophageal cells (blue-violet) transitioning to metaplastic cells (red-orange), a precursor to cancer, in response to chronic acid reflux (solid red-orange in background). Viewed from the opposite side, the same work displays the process of healing as metaplastic cells differentiate to normal ones.

among inspiring pieces by other artists combining science and art at the Sigma Xi STEM Art and Film Festival in Madison, Wisconsin, in 2019. I hope to continue exhibiting this installation in public health settings, offering people at clinics, hospitals, or elsewhere an opportunity to de-stress, learn, and reflect. The work will be on display this summer and into the fall at the William R. Bliss Cancer Center and the Cancer Resource Center at Mary Greeley Medical Center in Ames, Iowa. There, I plan to conduct a study into the work’s efficacy for providing an opportunity for self-reflection and combating health literacy issues. I will collect quantitative and qualitative information from those visiting the center through a survey that will inquire into viewers’ stress levels, reasons for being there, and comprehension of the subject matter, as well as any actionable outcomes. For example, I’m curious to see if the work motivates anyone to adopt new habits, such as using a positive outlook more frequently to improve memory. I am also interested in finding a permanent home for the installation after my study is complete.

With works like The Landscapes Within, I aim to show people that they can take a step back from their daily worries. I want to offer viewers an opportunity to hold a sustained focus, slow down to think, and open themselves up to positive actions that make the body more resilient. References Brand, S., T. Reimer, and K. Opwis. 2007. How do we learn in a negative mood? Effects of a negative mood on transfer and learning. Learning and Instruction 17:1–16. Fredrickson,  B. L. 2000.  Cultivating positive emotions to optimize health and wellbeing. Prevention & Treatment 3:1–25. Migliaccio, C. T., and A. Holian. 2010. Inflammatory cells of the lung: Macrophages. In  Comprehensive Toxicology, vol.  8, second edition, eds. C. A. McQueen and G. S. Yost, pp. 93–113. Elsevier Science.  Norman,  D. A.  2004.  Emotional Design: Why We Love (or Hate) Everyday Things.  New York: Basic Books.  Suzuki, W. 2015. Happy Brain, Happy Life. New York: HarperCollins Publishers.  Kim Moss teaches at Iowa State University in the Biological/Pre-Medical Illustration Program and the Department of Art and Visual Culture. View more of her work at www.kimmossart.com. Email: [email protected] 2021

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The Shift to a Bird’s-Eye View Remote sensing technologies allow researchers to track small changes on a large scale and enable studies of far-flung places from the comfort and safety of home. Elizabeth M. P. Madin and Catherine M. Foley

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here was a period in my life when my job title might as well have been professional fish watcher. Every day, I (Madin) would wake up, head out to a coral reef, and watch fish. Endless numbers of fish. Traveling halfway across the world to the remote Line Islands archipelago in the middle of the Pacific Ocean, I would spend days and weeks floating in the clear waters above the reef, recording details such as the exact number of bites a tiny fish takes. Imagine counting how many times a chicken pecks at the ground; it was a bit like that. These close observations of fish were a central part of my doctoral research on marine ecosystems. My goal was to understand whether humans, by harvesting the large, predatory fish, led the smaller, normally timid fish to become more daring in their nibbling of seaweed and foraging on coral reefs. The larger purpose was to understand a disturbing transition: Human activities have been transforming coral reefs from pristine, predator-filled oases bursting with colorful marine life into seemingly inert brown seascapes covered in seaweed and slime. This pattern has been observed on reefs throughout the world in recent decades, but the nuances of why and how this happens are not always clear. It was my hope that by investigating the mechanisms of change, my research would help guide wise decision-making and conservation policies, which in turn would help to ensure a sustainable supply of seafood for the hundreds of millions of people

worldwide who depend on coral reefs for food and jobs. But one can only be a professional fish watcher for so long. The time, expense, and logistics of traveling to these remote coral islands proved particularly difficult once my first child was born in 2009. Luckily, a chance conversation with fellow graduate student Thomas Adam (now an assistant research biologist at the Marine Science Institute at the University of California, Santa

Courtesy of Elizabeth M. P. Madin

At the beginning of her career, ecologist Elizabeth M. P. Madin (pictured in Palmyra Atoll, Line Islands) counted the nibbles of individual fish to calculate their effect on coral reefs. Now, she uses satellite images to study changes on a larger scale.

Barbara) led me to a dramatic shift in perspective. I discovered that the collective result of the fish behavior patterns that I had spent countless hours documenting underwater could also be seen . . . from space.

The huge, sandy rings surrounding coral reefs, where small fishes have eaten away all the seaweed, are visible in satellite imagery. The rings are created by interactions among predators and their prey and are indicative of healthy, well-functioning reef ecosystems. These rings are too big to be observed in their entirety underwater, so I had been—unknowingly— documenting them piecemeal. A space-based view opened up new opportunities to apply my research to the real-world question of how fishing affects coral reefs. It also presented new possibilities for studying Earth’s ocean ecosystems more broadly, which triggered a paradigm shift for my research. The broad perspective of satellite imagery allowed me to identify larger trends by observing changes on a global scale and comparing ecosystems over time and across space. View from Afar Remote sensing is the process of detecting and measuring phenomena without being physically present. Common remote sensing technologies include satellites and drones that observe the Earth from above, as well as radar, sonar, and lidar, which measure characteristics of far-away objects. Other forms of remote sensing include infrared camera traps that monitor nighttime wildlife without human interference, and tags that allow researchers to track animals; those methods let researchers get up close and personal with their subjects, but the monitoring occurs remotely. Although one of us (Madin) discovered the possibilities of remote sensing

QUICK TAKE Satellite images and other remote sensing technologies can provide information about global shifts and tiny phenomena—both the proverbial forest and the trees.

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These methods enable researchers to virtually visit regions that would otherwise be inaccessible, either because of the difficulty of travel or because of potential danger.

During the COVID-19 pandemic, remote sensing and monitoring technologies allowed researchers to continue their work while maintaining a safe social distance.

Catherine Foley

Drone video footage captured this turtle swimming above a coral patch reef in Kāneʻohe Bay, Hawaiʻi. Overhead images give ecologists a wider perspective on changes to coral reef ecosystems than can be obtained through close examination alone.

relatively late in her research career, I (Foley) relied on the technology from the start. My doctoral research applied remote sensing technologies to the formidable problem of counting seals and penguins in the subantarctic. In the early 2010s, many researchers assumed that penguin and seal populations were recovering from the extensive harvesting of the 18th and 19th centuries, but nobody knew for sure (and the answer is still somewhat unclear). There was a good reason for that uncertainty: Subantarctic travel is no small undertaking. South Georgia Island in the Southern Ocean, for example, is accessible only by ship; there are no permanent residents or airstrips, and the weather is extremely inhospitable. The obstacles to accessing the region make its animal populations incredibly difficult to study. And if you do manage to get to South Georgia Iswww.americanscientist.org

land, time is of the essence; spending weeks observing penguin colonies is simply not an option due to tricky logistics and tight research budgets. To circumvent these limitations, researchers use time-lapse camera traps to study changes in penguin colonies that occur over weeks or months. However, this approach does not answer the question of how large the total penguin populations are, or how those populations change over time. Although it was impossible for our research team to live at these penguin colonies for years at a time, we discovered that we could “visit” them frequently via satellite images and observe how colonies were changing in size, shape, and composition over time. Because satellites have been continuously orbiting the Earth for decades, we could even go back in time to start our observations and then continue to monitor these pen-

guin populations in near-real time from anywhere in the world. Problem solved. Our (the authors’) paths up to that point had set us on a trajectory to collaborate. In 2020, one of us (Madin) realized that she wanted to tap into the power of remote sensing in a way that went beyond her own skill set. She wrote an ad to recruit a postdoc with remote sensing chops who shared her interest in applying those skills toward conservation of ocean wildlife; the other of us (Foley) replied. Today, we are combining our vastly different skill sets to tackle new ecological questions that would be impossible to address separately. Our projects range from using satellites and drones to quantify how seagrass meadows recovered from a reduction in recreational boat use during the COVID-19 lockdown, to using head cams mounted on Hawaiian monk seals to understand how the activities of this threatened species affect the behavior of its prey. We are finding that the more we look, the more our eyes open to the seemingly limitless 2021

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penguinmap.com/NASA

Cuverville Island off the coast of Antarctica is inaccessible to humans for much of the year, but satellite images allow researchers to study the island’s penguin populations regardless of season. Although the individual birds are not visible, reddish-brown splotches of guano on the white snow indicate gentoo penguin colonies. Remote sensing techniques that groups such as Penguin Watch have relied upon for years were used more broadly during the pandemic because they allowed researchers to visit field sites virtually while adhering to stay-at-home orders.

possibilities for applying the rapidly evolving suite of remote sensing tools. Hidden in Plain Sight The first satellite images were captured in 1959. They were comparatively low in quality and resolution, but technology developed quickly, and

power, provided more opportunities to monitor animal populations via remote methods. The resolution of satellite images is now so sharp that we can sometimes even identify individual large animals. We can detect the migration of caribou and musk oxen across Alaska and the Arctic via publicly

Motion sensors and accelerometers can recognize how animals are oriented in the water and how fast they are moving, allowing researchers to identify specific behaviors even when they can’t see them. soon the images provided enough detail to detect the presence of animals. In 1980, for example, scientists used satellite imagery to detect areas of bare ground in South Australia, a telltale sign of wombat burrows. Advances in satellite imagery, as well as improvements in computing 290

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available images from Landsat—a joint program of NASA and the U.S. Geological Survey—which maintains the longest-running continuous spacebased record of the Earth. Newer, higher-resolution satellite imagery can also identify animal migrations over the African savannah. Researchers are

also using remote sensing to monitor species that are not readily apparent to humans even when we are nearby. For example, in 2019 a research group from ecologist Heather Lynch’s lab at Stony Brook University demonstrated that machine learning algorithms are capable of detecting large whales in satellite imagery. The algorithms search satellite imagery for signs of whales at the surface of the water—large, dark, shiny bodies in the middle of the ocean—and can provide researchers with a relative number of whales in an area. When this type of information is paired with behavioral data collected in the field, it provides an incredibly powerful tool for monitoring massive spatial areas. Remote sensing technologies have revolutionized whale research in other ways as well. These mysterious creatures of the deep have long puzzled scientists, who only grasp brief glimpses of their lives at the sea surface. Now, researchers use satellite tags to track where they migrate and move. Three-dimensional motion sensors and accelerometers can recognize how the animals are oriented in the water and how fast they are moving, allowing researchers to identify specific behaviors, such as lunge feeding, even when they can’t see the whales. These data are especially useful when paired with video from animalborne cameras. By mounting small video cameras (often referred to as crittercams) directly onto animals, researchers can observe how they hunt and move through environments that would otherwise be invisible to us. Many other species have proved equally challenging to observe, but for different reasons. Polar bears are important to monitor as they face the threat of a changing climate and melting ice. These large predators cannot be studied up close because they are too dangerous to approach, but their camouflaged pelts make them difficult to observe from afar. In 2015, conservation biologist Michelle LaRue (now at the University of Canterbury in Christchurch, New Zealand) and her colleagues found a way to assess the population of polar bears on Rowley Island, Canada, entirely with satellite imagery. The team used a technique called automated image differencing, which compares images at the pixel level to identify minute changes, to pinpoint polar bear locations and population density.

Zooniverse Penguin Watch

Cameras mounted in Antarctica during the austral summer enable year-round monitoring of various penguin populations. Zoologist Tom Hart and his Penguin Watch team install standard trail cameras on semipermanent stands (left, with a colony of gentoo penguins). The images from these cameras are made available on the Zooniverse platform to citizen scientists, who help track the location and movements of different groups of penguins. In the photograph of chinstrap penguins (right), colored dots represent individual clicks from volunteers.

The creative use of satellite imagery for tracking animal populations doesn’t stop there. In 2014, Lynch and LaRue teamed up to tackle a much smaller problem: Adélie penguins. Although individual Adélies are too small to identify in satellite images, it turns out that when they group together, they produce a lot of guano. And Adélie excrement is particularly festive—it is bright pink, making it easily identifiable in satellite imagery. Lynch and LaRue conducted the first global census of Adélie penguins and based their findings entirely on the presence of guano stains in satellite imagery. In their analysis, Lynch and LaRue discovered 17 Adélie penguin colonies that were previously unknown to scientists, and 13 that appear to have disappeared from the Antarctic continent. Penguin science has been a hotspot for innovation in the use of remote sensing methods. While working in the Lynch lab, one of us (Foley) extended the team’s area of interest to include king penguins on subantarctic South Georgia Island. In 2018, the lab began supplementing satellite data with images collected by uncrewed aerial vehicles (also known as drones) from a remote region of Antarctica called the Danger Islands. As implied by their ominous name, these islands are difficult to reach and are therefore rarely visited by scientists. Lynch’s lab used highly overlapped photo transects from drones and a prowww.americanscientist.org

cess called photogrammetry to create 3D reconstructions of the islands. Imagine a mown lawn where each pass of the lawn mower had about 90 percent overlap with the one before. The photos that Lynch collected overlapped in a similar manner, and variations in the angle of the images brought out the features in the landscape. Photogrammetry uses matching points on multiple images and applies the rules of geometry to reconstruct a 3D surface. By using this method, Lynch’s team was able to recreate a 3D model of the Danger Islands and identify them as critically important habitat for seabirds. Aerial surveys are not the only technology on the leading edge of remote sensing in ecology research. Oxford University zoologist Tom Hart leads the Penguin Watch research project, using time-lapse cameras to monitor breeding activity in hundreds of penguin colonies around Antarctica and the Southern Ocean, all from the comfort of his sofa. Hart uses trail cameras—similar to ones you might set up in your backyard—mounted on semipermanent stands. Currently, Penguin Watch has 92 cameras mounted across the region, with an additional 40 cameras installed and maintained by collaborators. With Hart’s help, several more “Watch” projects have launched on the Zooniverse citizen science platform, including my (Foley’s) own project, Seal Watch, which applies the methods Hart developed to the task of identifying

breeding activity among subantarctic seals. The Seal Watch team uses this data to monitor the timing of breeding events and establish relative estimates of breeding success across rookeries. This information is critical to our understanding of population dynamics and recovery in species that were once hunted to the brink of extinction. The same tools and techniques used to observe whales, polar bears, and penguins can also monitor some of the smallest animals on Earth. Corals are marine invertebrates, each typically only a few millimeters long, which collectively can form large, reef-building colonies. Currently facing the menacing and synergistic effects of increases in sea temperature, stronger and more frequent storms, and ocean acidification, corals have gained increased attention and concern for their precarious state on a rapidly changing planet. One of our current projects uses drones to create 3D maps of reefs during and after coral bleaching events, when hotter-than-normal water temperatures cause corals to turn a ghostly white before either dying or, if lucky, recovering. The maps allow us to virtually revisit and remeasure with great precision the exact same coral colonies year after year and track their demise or recovery. (Even for most coral experts, trying to re-find an individual coral colony on a reef is a bit like trying to relocate a particular tree in a rainforest.) We’re in the process of developing an artificial intelligence algorithm to automatically identify bleached corals from drone imagery, which will enable faster, cheaper, and easier detection of coral bleaching in near-real time. Our work dovetails with the Allen Coral Atlas, a collaborative project that 2021

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441 kilometers Map data: Google, USGS, USDA, ESA

Satellite images from Google Earth demonstrate the dramatic change to Kayford Mountain in West Virginia between December 2008 (top) and September 2015 (bottom). Mountaintop removal mining exposes coal seams from above, making it unnecessary to tunnel underground. Because satellites such as Landsat have been surveying the Earth for decades, researchers can compare images of landscapes over time and see the long-term effects of human actions on ecosystems.

includes the University of Arizona and the University of Queensland in Australia. The project is using satellite imagery paired with machine learning algorithms and in situ survey data from around the world to build the world’s first high-resolution global coral atlas. Both efforts will help document how coral reefs around the world are changing in response to human activities. Surveying Changing Landscapes Mining operations are among the most ecologically devastating human activi292

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ties on the planet. Unregulated mining can cause complete ecosystem loss, rapid degradation of air and water quality, and the pervasive release of pollutants. Advances in remote sensing methods have allowed for the rapid identification of harmful mining operations as well as monitoring of their direct and indirect effects on surrounding ecosystems. A 2018 study led by Andrew Pericak (now a geographic information systems analyst at the Tennessee Department of Transportation) used Landsat satellite imagery and the Google Earth

Engine to show that between 1985 and 2015, 2,900 square kilometers—an area larger than Rhode Island—had been newly mined in Central Appalachia. Cumulatively, the mining footprint within the region was 5,900 square kilometers, meaning that nearly half of that area was mined in a 30-year period. The researchers have made their algorithm and data publicly available to the scientific community, fostering a collaborative environment to document changes. With increases in technological innovation and computing power, we may soon have the ability to monitor landscapes in real-time and use the technology to target interventions and raise public awareness, perhaps sparking policy changes that could halt the destruction. Remote sensing is also providing a clearer picture of the ways that farming, overgrazing, rising temperatures, and diversion of water resources can lead to drought events and desertification. Climatologist Arden Burrell of the Woods Hole Research Center and his colleagues constructed a time series of satellite images to study global land use data between 1982 and 2015. They found that during this time, human-induced climate change degraded nearly 13 percent of the world’s drylands—a region equivalent to half the area of Europe. In a paper in Nature Communications, they estimate that these ecosystem changes affect 213 million people, the vast majority (93 percent) of whom live in developing economies. Continued desertification poses a serious threat to roughly 40 percent of terrestrial habitats—an area populated by approximately 1 billion people. (See “Dying for a Drink,” September–October 2019.) A less direct effect of anthropogenic climate change is the way it is changing fire patterns across the world. Imagery from satellites and drones has proved invaluable at predicting, detecting, monitoring, responding to, and recovering from wildfires globally. Using remotely sensed environmental data on wetness, wind, rainfall, and vegetation, researchers are able to create risk maps for wildfire outbreak in near-real time, providing local authorities with the necessary information to prepare and potentially prevent loss of life and property. When fires break out, it becomes essential for firefighters and residents to know where active fires are burning and where smoke and ash could potentially threaten human health. When

rampant wildfires ravaged the Pacific Northwest in the autumn of 2020, the U.S. National Oceanic and Atmospheric Administration (NOAA) satellites played a pivotal role in pinpointing active fires and understanding how the resulting smoke was affecting regional and national air quality. Satellites are also used in the aftermath of devastating fire events to monitor and manage damaged lands. In 2017, the grasslands of the U.S. Great Plains faced a devastating wildfire that burned thousands of acres of grazing lands. Scientists monitored satellite imagery to assess the region’s recovery and to guide land management policies that would prevent overgrazing of recovering areas. As anthropogenic climate change intensifies, the frequency and severity of wildfires is predicted to increase as well. In a 2020 study published in Remote Sensing, environmental scientist Jingjing Li of California State University, Los Angeles, and her colleagues used Landsat imagery to evaluate wildfires occurring between 1984 and 2017. Their results validated the predictions of climate models, showing that both fire frequency and the area affected are increasing at a statistically significant rate in every region of the United States with the exception of the Northeast. Bird’s-Eye View of Displacement Remote sensing technologies have applications well beyond monitoring the natural world; they can also be used to track humanitarian crises and geopolitical issues. Using satellite imagery and other remote data, researchers can identify violence, estimate displaced populations, and track the movement of refugees. Often, the first step in solving humanitarian crises is to gain widespread recognition of the problem. Doing so can be especially challenging when they occur in remote areas. Images from remote sensing technologies can bring attention to these events, which might otherwise go unnoticed by the wider world, and in turn galvanize assistance or even intervention. The authors of a 2014 study in the International Journal of Remote Sensing, for example, used satellite images of nighttime light pollution to estimate destruction and displacement associated with the Syrian civil war. They found that from 2011 through 2014, nighttime light declined in Syria by 74 percent, www.americanscientist.org

NOAA

Real-time images from Landsat of wildfires showed the spread of smoke in California in October 2020. This type of information can alert emergency workers to new or growing problems and inform residents of threats to air quality that are heading their way. (The white line indicates the boundary between California and the Pacific Ocean.)

and that regional declines in nighttime light were correlated with the estimated number of refugees departing. A 2008 study published in the same journal documented the genocide occurring in the Darfur region of Sudan by surveying 352 villages using NOAA’s publicly accessible Landsat data. The satellite images showed that from 2003 through 2004, half of the villages in Darfur had been burned and razed, as identified by a sharp drop in albedo (reflected light) in the affected areas. Some humanitarian efforts are now pairing remote-sensing information with mass outreach to spur public awareness. An early example came in

lages that had been burned, clusters of displaced persons, and the resultant refugee camps. Despite the many benefits of remote sensing, the technologies have the potential to be used for nefarious purposes. How might bad actors make use of democratized remote sensing information that was intended for good? The approximately 25 million closedcircuit television (CCTV) cameras in operation worldwide are one form of remote sensing technology that has provoked controversy. On the one hand, in the United Kingdom there is roughly one CCTV camera installed for every 14 people.

Without remote sensing technologies, we would have lost an entire year’s worth of critical penguin population data. the form of the “Crisis in Darfur” project, in which the U.S. Holocaust Memorial Museum Genocide Prevention Mapping Initiative teamed up with Google Earth to shine a spotlight on the Darfur genocide. Remotely sensed data, on-the-ground information, photo and video imagery, and eyewitness accounts were compiled to enable users (including policy makers) worldwide to locate and visualize instances of past, emerging, and potential genocides geographically, including vil-

Although there has been some dispute over the widespread use of domestic surveillance, the approach has generally received support. A 2014 survey found that 86 percent of British citizens approved of the use of CCTV cameras in public places to increase safety. The March 2021 death in South London of Sarah Everard, a 33-year-old marketing executive, seems to have heightened the call for increased surveillance as a means to protect women and girls. That same month, the British government 2021

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Two satellite images showing nighttime light in Syria in March 2011 (left) and February 2014 (right) indicate that the country’s population decreased sharply over that period. Despite widespread news coverage of the Syrian civil war, it can be difficult to understand the effect of the drawn-out conflict. The dramatic reduction in nighttime light in Damascus, Homs, and Aleppo provides a stark illustration of the drop in population in those cities during the humanitarian crisis.

pledged £25 million to increase lighting and CCTV coverage in public spaces. On the other hand, CCTV cameras and other remote monitoring systems could be used for surveillance and to combat democratic efforts. Since protests began in Hong Kong in the spring of 2019, CCTV footage has helped the government identify thousands of people, who were subsequently arrested under colonial-era public assembly laws and may face up to 10 years in prison. In a country dominated by government surveillance, protesters are facing an uphill battle to maintain anonymity. This deep divide will only be exacerbated as technologies advance. In 2020 the Moscow government deployed newly available facial recognition software on the city’s 160,000 CCTV cameras. But these facial recognition algorithms are highly contested, and studies have demonstrated that they often have an alarming gender and racial bias. (See “The Dark Past of Algorithms That Associate Appearance and Criminality,” January–February.) Monitoring the Pandemic During the COVID-19 pandemic, various remote sensing technologies have been deployed to track the disease and its cascading effects. On the scale of individual humans, thermal scanning has been used to monitor the body tem294

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peratures of large numbers of people simultaneously—for example, in Wuhan, China, where thermal cameras were mounted on drones. At the population level, monitoring of mobile phone networks in Turkey was used in the first wave of the pandemic to gauge how well physical distancing measures were working. Likewise, mobile phone apps, such as the COVIDSafe app implemented by the Australian government, use Bluetooth to track people with whom a user may have had close contact and then alert the user if any of those people tests positive for COVID-19. Globally, a dramatic reduction in greenhouse gas and other emissions as a result of widespread human confinement—the “COVID anthropause”— and their subsequent return to prepandemic levels are clearly observable via satellite images. For example, when nitrogen dioxide levels in various cities in China before, during, and after COVID-19 lockdowns on human movement and factory work are compared, a striking correlation emerges: There is a dip in nitrogen dioxide levels when the lockdowns occurred, and a rebound after they were eased. The dip gave a brief respite to human health and to the climate, both of which are negatively affected by excess levels of this and other trace gases in the atmosphere. These data are vi-

sually stunning and demonstrate just how vast the cascading effects of the tiny SARS-CoV-2 pathogen really are. The myriad effects of this anthropause on biodiversity are also evident through the “eyes in the sky” that satellites provide. For example, we can track the number and movement of fishing vessels over the global oceans via satellitederived data from transponders originally designed to prevent at-sea collisions. These transponders are installed on large, oceangoing vessels and regularly broadcast the geographic location of each vessel to a satellite, resulting in a publicly available database. By continuously collecting the nearly halfmillion vessel tracks, data scientists are now able to create a map of global fishing effort across the world’s oceans, something that would have been impossible even 10 years ago. Remote sensing has also offered solutions for scientists and others whose ability to do their job has been compromised by the pandemic lockdowns. Many ecologists, for example, cannot conduct field work while stay-at-home orders and social distancing measures are in place. This problem is particularly acute for marine scientists who travel to their study sites on boats where social distancing is often impossible. Many scientists have had to get creative and pivot to the use of remote sensing approaches to keep their work going. In our own experience, whereas previously we would have gone out on the water in boats to count the number of recreational fishing vessels visiting our seagrass-recovery study sites in

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Kāneʻohe Bay, Hawaiʻi, we are now completing these tasks using frequent, very-high-resolution satellite imagery. Planet, Inc.’s PlanetScope satellites now provide on a daily basis high-resolution images in which each pixel is equivalent to 3 meters on Earth; these images allow us to measure the extent of changes in seagrass beds, which are frequently damaged by recreational boats and visitors. Similarly, most national Antarctic programs and universities did not participate in the most recent Antarctic field season. Whereas in a normal year, one of us (Foley) would have voyaged south to set up experiments and to change cameras, this year the team watched the penguins from space. Without remote sensing technologies, we would have lost an entire year’s worth of critical penguin population data. These necessary changes to the way research was conducted during the pandemic may have lasting effects on fieldwork, just as some companies are adjusting their policies and procedures to allow remote work for their employees over the long term. Our current ability to monitor changes in biodiversity and landscapes, and to identify and respond to humanitarian and geopolitical tensions, is far-reaching. However, as new technologies continue to develop, our ability to use remotely sensed data will likely be limited only by our imaginations. Academics have already proposed the deployment of dedicated constellations of small, relatively inexpensive CubeSats (which can be www.americanscientist.org

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European Space Agency satellite images captured levels of tropospheric nitrogen dioxide (NO2, a gas that has been linked to asthma and other respiratory illnesses) over China in February of 2019, 2020, and 2021. As governments issued stay-at-home orders during the COVID-19 pandemic, many people speculated about possible environmental benefits from reduced travel. These images demonstrate that there was a pandemic-related reduction in NO2 levels, but that the change was temporary.

mounted with a selection of sensors) exclusively for scientific endeavors and disaster management in remote corners of the globe, allowing scientists the ability to completely control the timing and acquisition of data for specific projects. We will no doubt face future pandemics and episodes of massive social unrest, while also continuing to confront issues related to climate change, the alteration of landscapes and seascapes, the dwindling of resources and space, geopolitical tensions, and humanitarian crises. Documenting the scale of the many resulting problems will, in many cases, require a “macroscope” of the sort that remote sensing can offer. Bibliography Borowicz, A., et al. 2019. Aerial-trained deep learning networks for surveying cetaceans from satellite imagery. PLOS One doi:10.1371/journal.pone.0212532. Burrell, A. L., J. P. Evans, and M. G. De Kauwe. 2020. Anthropogenic climate change has driven over 5 million km2 of drylands towards desertification. Nature Communications 11:3853. Dornelas, M., et al. 2019. Towards a macroscope: Leveraging technology to transform the breadth, scale and resolution of macroecological data. Global Ecology and Biogeography 28:1937–1948. LaRue, M. A., et al. 2015. Testing methods for using high-resolution satellite imagery to

monitor polar bear abundance and distribution. Wildlife Society Bulletin 39:772–779. Li, X., and D. Li. 2014. Can night-time light images play a role in evaluating the Syrian Crisis? International Journal of Remote Sensing 18:6648–6661. Lynch, H. J., and M. A. LaRue. 2014. First global census of the Adélie Penguin.  The Auk 131:457–466. Madin, E. M. P., E. S. Darling, and M. J. Hardt. 2019. Emerging technologies and coral reef conservation: Opportunities, challenges, and moving forward. Frontiers in Marine Science 6:727. Pericak, A. A., et al. 2018. Mapping the yearly extent of surface coal mining in Central Appalachia using Landsat and Google Earth Engine. PLOS One doi:10.1371/journal.pone.0197758. Prins, E. 2008. Use of low cost Landsat ETM+ to spot burnt villages in Darfur, Sudan. International Journal of Remote Sensing 29:1207–1214. Salguero, J., J. Li, A. Farahmand, and J. T. Reager. 2020. Wildfire trend analysis over the contiguous United States using remote sensing observations. Remote Sensing doi:10.3390/rs12162565.

Elizabeth M. P. Madin is an assistant professor at the Hawaiʻi Institute of Marine Biology, University of Hawaiʻi. She researches how the intersection of human activities and animal behaviors can lead to cascading effects through food webs. Catherine M. Foley is a postdoc at the Hawaiʻi Institute of Marine Biology. Her research is concerned with developing the use of emerging technologies for marine conservation and management in a variety of ecosystems. Email for Madin: [email protected] 2021

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How Endocrine Disruptors Affect Menstruation The ubiquity of phthalates and other substances known to interfere with hormonal pathways disproportionately harms people with periods. Kate Clancy

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n 2017, a Korean media outlet decided to investigate the chemicals found in commercial menstrual pads, based on the advocacy and awareness-raising efforts of the Korean Women’s Environmental Network, who had pointed out that menstruating people seemed to be developing rashes, discomfort, and even infertility from the pads. This group sent samples to reproductive toxicologists Jodi Flaws and Jay Ko at the University of Illinois, where I am also employed. Flaws and Ko found volatile organic compounds and phthalates in every single sample of sanitary pads and disposable diapers they received, and published their results in Reproductive Toxicology. The products they sampled were made in 2017 and came from Korea, the United States, Japan, Finland, France, and Greece; the researchers were kept ignorant as to the sources of their samples as they were conducting their analyses, to avoid bias. Although the quantities of volatile organic compounds were not too alarming—they weren’t too different than what we are already exposed to, and you can reduce them by letting these products air out a bit before using them—the phthalates were another story. Phthalates, a class of endocrinedisrupting chemicals, are widely known to be harmful to human health. Phthalates are very common in plastics, cosmetics, and apparently men-

strual pads, because certain phthalates (there are many of them) can help a substance dissolve or can make plastics harder to break. Women, femmeidentified gender minorities, and children are most vulnerable to exposure because phthalates are so often found in the products they are more likely to use: cleaning products, cosmetics, baby toys, and more. (To be clear, this is a general statement based on how gender roles inform and even constrain choices.) Additionally, people who experience incontinence, from babies and toddlers to postpartum people to elders, are going to be exposed to diapers, and menstruating people (including nonbinary people and transmen) to menstrual pads. These put phthalates right up against our thin genital skin. Endocrine-disruptor exposure also comes from the food we eat: Foods that are encased in plastic (wrapped produce, plastic water bottles) are likely to have absorbed the chemicals used to give that plastic its structure or softness. Some prescription and over-the-counter medicines are even coated in phthalates. When we receive intravenous fluids in the hospital, those fluids have been sitting in plastic made with phthalates, and although these injections do not seem to have significant short-term effects, rodent studies suggest that those literal injections of phthalates can have

intergenerational effects on the health of our children and grandchildren. Whenever I find myself discussing this issue with others, I tend to encounter two main reactions: Either people immediately want to know what they should throw out (and what they should use as replacements), or people throw up their hands at the futility of avoiding endocrine disruptors. I understand and have harbored both of these viewpoints at times. However, I think a third reaction is possible, one where we step back and recognize the broader structural problems that have brought us here. We must consider our varying responsibility and power within those structures that have put all of us at risk, but some of us especially so based on sexism, racism, and ableism, and sometimes just based on physiology. This approach means sitting with this knowledge for a minute, rather than immediately reacting. After all, these endocrine disruptors are not going anywhere soon; we have the time. Periods on Phthalates Krakow, Poland, is one of my favorite cities on the planet. It is one of the first places I ever visited on my own, and is the closest city to the rural mountainous region where I have conducted much of my fieldwork on menstrual cycles. I remember being picked up at the airport on my first visit in 2002 by my mentor and collaborator, public

QUICK TAKE Women, gender minorities, and children are most likely to be exposed to endocrine disruptors because of the products they are more likely to use.

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People are exposed to many different types of endocrine disruptors, from phthalates to lead. Many are known to be harmful to human health.

The solution is not as simple as deciding on acceptable thresholds of chemicals or replacing ingredients. The key question is: How were these materials permitted in the first place?

Portia Munson

Portia Munson’s art installation Pink Project (1994–ongoing) displays the overwhelming number of pink plastic products marketed to girls. Women, gender minorities, and children are particularly vulnerable to exposure to endocrine disruptors, such as phthalates, because these chemicals are found in the products they are more likely to use, including plastics, cosmetics, menstrual pads, cleaning products, diapers, and baby toys.

health researcher and anthropologist Grazyna Jasienska of Jagiellonian University, in part because of where she had parked in the city. Jasienska lived in a lovely apartment in the Old Town, and as a resident, she had a special permit to drive and park in the central part of the city. Although some of the initial decisions to limit traffic in Krakow were about tourism and support for local residents, one of the by-products of these driving and parking restrictions has been that it may reduce some local pollution. Because Krakow sits in a valley, air pollutants can drift in from surrounding industry and linger, and traffic emissions can stagnate there as well. The Old Town area is gorgeously preserved, with stone buildings that are many hundreds of years old and a city center with churches, flower sellers, and www.americanscientist.org

booths of traditional souvenirs such as amber jewelry and embroidered blouses. Air pollutants are bad for the buildings, bad for the inhabitants, and bad for tourism. The air pollution from traffic, particularly from higher-emission cars, comes from particulate matter (bits of dust, soot, and smoke of varying origins), sulfur dioxide, carbon monoxide, and nitrogen oxides. (See “Air Pollution and Sunlight Q&A,” January–February 2016.) A 2017 paper in the International Journal of Environmental Research and Public Health by Anna MerklingerGruchala of Krakow University, Jasienska, and Maria Kapiszewska, also of Krakow University, looked at these different types of air pollution together, to try and understand whether fossil fuel combustion from industry and heating, traffic fuel emissions, or both

together produce cumulative effects on the menstrual cycle. The sampling period was 2001 to 2003, right around the time of my first visit to Poland. My colleagues looked at the air pollution measures in Krakow at that time, based on municipal ecological monitoring data by the state, and menstrual cycle characteristics from 133 research participants living in the city. In this study, there were no effects on the menstrual cycle when considering any one pollutant on its own. However, the authors found that particulate matter and sulfur dioxide exposure together were associated with a shortened luteal phase (the second half of the menstrual cycle, starting at ovulation and ending at menses). These pollutants derive mostly from fossil fuel emissions—the kind that come from older heating units and factories. The effects on the menstrual cycle of the other pollutants studied—carbon monoxide and nitrogen oxides—were not statistically significant in this sample. The authors mathematically estimated that exposure to air pollution 2021

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Benny Mazur. (CC BY 2.0)

In the late 1970s, artist Jay Critchley began finding tampon applicators on his local beaches around Cape Cod, Massachusetts, and making art out of them. At first, he didn’t know what the items were (locals called them “beach whistles”). When he found out, he began to bring awareness to the issues surrounding menstrual product waste by dressing up as Miss Tampon Liberty (right), as described in a recent piece on the waste-focused research website Discard Studies. Menstrual products made with plastic not only expose menstruators to endocrine disruptors, they also play a major role in the ubiquity of modern plastic pollution. Jay Critchley

at the level found in this study led to a shortening of the luteal phase by a third of a day. Given that nearly all embryo implantations occur within a three-day window in the middle of the luteal phase, a disruption by a third of a day could represent a significant biological event. A shorter luteal phase also means a shorter menstrual cycle, which means in the long run more ovulations and more periods. Some research has suggested that a higher frequency of ovulation may be associated with an increased risk of reproductive, particularly ovarian, cancer. A number of other papers have looked at the effects of air pollution on fecundability (the probability of conception in a given cycle), fertility (number of offspring), and fetal and infant health, and they have all reached similar conclusions. Several studies looked at people who are occupationally exposed to certain pollutants. Nail salon workers experience occupational exposure to phthalates, phthalate alternatives, and volatile organic compounds; recent work published in Environmental Science and Technology found the problem may lie not only in nail product formulations but also in nail salons not adhering to proper ventilation guidelines. What’s 298

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more, the volatile organic compounds emitted from salons are probably contributing to volatile pollution more broadly, according to a 2019 paper in Indoor Air. Traffic police are exposed to particulate matter and other airborne pollutants; these subjects have been found to have lower estradiol concentrations (a type of estrogen), and higher follicle stimulating hormone concentrations (a hormone important to ovulation) than controls who are less exposed. Another study, published in 2017 in Human Reproduction, looked at mostly middle class white women from Michigan and Texas, and even with their relatively low exposure to air pollution compared to other people, the authors found some weak associations between acute exposure to some pollutants and how many cycles it took for couples to conceive. Similar research, published in 2018 in Human Reproduction, has shown reduced in vitro fertilization rates with increased exposure to certain air pollutants. Then there are the endocrine disruptors in our water. Many communities in the United States are exposed to lead, cadmium, arsenic, and other heavy metals in the water they drink. (See “Arsenic, the ‘King of Poisons,’ in Food and Water,” January–February 2015;

“First Person: Mona Hanna-Attisha,” September–October 2019; and “Moving Forward After Flint,” May–June 2016.) In many parts of the country, these exposures are considered to be under an acceptable threshold by, say, the U.S. Centers for Disease Control and Prevention (CDC), but not necessarily by the members of those communities. The CDC’s reference value for the acceptable quantity of lead in the blood, for instance, is 5 micrograms per deciliter and under. This is a recent shift from 10 micrograms per deciliter and under, and other experts recommend moving down this value even further to 2 micrograms per deciliter. Experts at the CDC and elsewhere are clear that there is no actual acceptable amount of lead or any other endocrine disruptor in the body: The tightrope they are walking is one of risk assessment (more on that later). I found examples in Korea, Mexico, Canada, and the United States where lead exposure that led to a blood concentration of less than 5 micrograms per deciliter still had a negative effect on children’s cognition, growth, and development. And despite the known risks, much higher exposures are experienced by kids in Nigeria whose cough syrups are often contaminated

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In a study based in Krakow, Poland, exposure to particulate matter and sulfur dioxide, which are mostly derived from fossil fuel combustion, was associated with a shortened luteal phase, the second half of the menstrual cycle from ovulation to menses. A shortened luteal phase can decrease the time during which egg fertilization can occur and, in the long run, can mean more periods over a person’s lifetime. A higher frequency of ovulation may also be associated with an increased risk of reproductive cancers. (Figure from A. Merklinger-Gruchala, G. Jasienska, and M. Kapiszewska, International Journal of Environmental Research and Public Health 14:816.)

with lead, or by child laborers in Pakistan who work in battery recycling plants, an occupation with significant exposure to lead. These kinds of effects, from learning disabilities to shorter stature to delayed growth or menarche (age at first period), have downstream effects. Although lead is discussed most frequently in terms of the significant harm it causes to child development, this endocrine disruptor can also influence the reproductive systems of adults. Lead exposure does not seem to lower the concentrations of estrogens in the body; instead, it interferes with estrogen receptors in a way that can block ovarian follicle development or embryo implantation, and suppress hormone secretion during puberty. From here, we could find ourselves going back to where we started: the endless endocrine disruptors found in plastics, cleaners, cosmetics, and food. Bisphenols and phthalates, parabens, polychlorinated biphenyls, heavy metals, and all sorts of other chemicals are in our pesticides, packaging, and porerefining serums. (See “Plastics, Plastics Everywhere,” September–October 2019.) Exposure to some endocrine disruptors seems to delay menarche, yet exposure to others largely accelerates it. Phthalates and bisphenols in particular are implicated in endometriosis and endometrial cancer because both, as weak estrogens, can disrupt the natural estrogen-to-progesterone ratio www.americanscientist.org

in the body and therefore encourage extra growth of uterine tissue. Phthalates, even at lower doses, influence adult reproduction in mice. Most of us are exposed to many different types of endocrine disruptors that may all exert slightly different and even opposing effects, so it is hard to say for sure which ones cause the most harm, or, if you are a company relying on these chemicals, whether they really cause any harm at all. Endocrine disruptors even have effects across generations. In the case of lead, much of it is stored in bone. Because bone turnover increases in

prenatally exposed generation, but also in the unexposed offspring of the following generation: the grandchildren of the originally exposed parents. Exposure to endocrine disruptors, then, can affect generations of children who are completely unexposed, which means that even with tighter regulation today, some populations may continue to experience disruptions of development, puberty, menstrual cycle function, and reproduction for years to come. Many of us in the United States, with our individualistic culture, continue to think of these problems as ones that affect individuals, and therefore as having individual solutions. In addition to the fact that I now vent my disposable menstrual pads in my bathroom to let them release volatile organic compounds before I place them against my body, I have switched my toddler to a combination of reusable and disposable bamboo pullups, and my kids

Phthalates and bisphenols are implicated in endometriosis and endometrial cancer. pregnancy and because lead can pass through the placenta, fetuses can experience significant lead exposure if their mothers were previously exposed. Researchers have just started measuring the epigenetic effects of phthalates across the generations—that is, the ways in which the expression of genes can be modified, and those modifications passed down, even without changes to the DNA itself. Epigenetic effects have the potential to occur not only in, say, a

now eat off stainless steel instead of using plastic plates and utensils. But you might also have noticed that although many of these exposures come from household objects we are bringing into our homes, other exposures are not up to us. Air and water pollution get into our homes and can be found not only in our food and water but also in the dust under our beds. There are ways our built environment, landscape, and neighborhoods can protect us, but even 2021

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Nail salon workers experience occupational exposure to phthalates, phthalate alternatives, and volatile organic compounds. A study of 10 nail salon workers compared concentrations before and after their shifts (green and orange, respectively) with females in the general U.S. population (blue). Most compounds were similar or higher in the general population. But metabolites of the phthalate alternative di-2-ethylhexyl terephthalate (DEHTP), MECPTP (mono-2-ethyl-5carboxypentyl terephthalate) and MEHHTP (mono-2-ethyl-5-hydrohexyl terephthalate), showed the greatest change in concentration in nail salon workers. The problem may lie not only in nail product formulations, but also in nail salons not adhering to proper ventilation guidelines. (Graph adapted from J. A. Craig et al., Environmental Science and Technology 53:14630.)

here we can see that gender and race continue to play a role in who can access risk-reducing resources. Going Green When I was in graduate school, the nearest park with running paths was eight blocks from my apartment. Between union organizing, teaching, and lab work, I had a lot of long days and so I often wanted to work out early. But the nearby East Rock Park in New Haven, Connecticut, was a bit creepy to run in alone, so I tended to go to the gym or run with a friend; even with a friend along, we often opted to run at 300

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the nearby high school track instead of going to the park. Green spaces are supposed to be good for us: They provide ways to reduce air and noise pollution, avoid indoor pollution, and get some physical activity. These are all good for menstrual health. But who can use them? Women, gender diverse, and gender nonconforming runners do not feel comfortable running alone in many settings, for good reason: They have both legitimate and acculturated fears for personal safety. I’ve had cars pull over and men yell at me to smile; an acquaintance recently shared a time a driver pretended to hit

her in a crosswalk. And sexism is not the only factor that can put you at risk when you try to enjoy the outdoors. Tamir Rice was playing in a park. Ahmaud Arbery was going for a run. Green spaces are supposed to be places for people to reduce their psychosocial stress and improve their mental health, but people who are not men don’t necessarily experience them that way. In one study, published in 2014 in Landscape and Urban Planning, researchers had participants go through a classic stress test, and then exposed them to realistic, three-dimensional videos of neighborhoods with varying amounts of greenery to measure whether greenery exposure had any effect on participant recovery from the stress test. The researchers found that the men who participated had mild improvements in recovery, but the women did not. In another paper, published in 2014 in the Journal of Epidemiology and Community Health, researchers looked at green space availability within neighborhoods as well as a number of mental health indicators: Again, there were different relationships between mental health and green space by gender. For men, the relationship was linear, meaning the more green space in their neighborhoods, the better their mental health. For women, however, the relationship was U-shaped, where better mental health was associated with moderate rather than low or high green space. The greatest benefit of green space for mental health in men was seen starting in their early thirties and remained fairly stable throughout their lives; for women, there was no benefit of green space until their mid-forties, and the benefit then increased with age. As a woman in my forties, I can say that my experience with street harassment has dropped off considerably, and I can’t help but wonder if that helps explain the gender difference. When it comes to endocrine disruptors, one of the main things a green space should do is serve as a literal buffer between a person and these pollutants. And this buffering has been supported in two recent studies published in Environmental Research, one out of the United States and one out of Iran. These papers have shown that exposure to air pollutants is associated with lower anti-Müllerian hormone levels—this hormone is often used as a rough estimate of one’s “ovarian age,” and a lower value of anti-Müllerian

hormone generally corresponds to fewer eggs. This finding matches the aforementioned literature that many endocrine-disrupting pollutants can compromise menstrual health. Both studies have also shown that green space in one’s neighborhood is associated with an increase in antiMüllerian hormone; in the U.S. sample, the green space effect was only true if the air pollutants were also low. Air pollution and green space are differentially distributed in the United States by socioeconomic status and race. So, not all communities with access to green space are able to reap their health benefits (which extend far beyond buffering from pollution exposure), because of the ways air pollution or safety concerns nullify any of the effects. Is Resisting Phthalates Futile? If any of you are like me, you’ve hit this portion of the article and wanted to go on a shopping spree to replace all the plastic in your home. A menstrual cup might reduce one’s exposure to some endocrine disruptors—but only when one buys the most expensive cups, because medical-grade silicone is not a strongly regulated material and in some cases could still contain endocrine disruptors. These cups can still leak, so a heavier bleeder will need a backup, but most disposable and many reusable backups also contain plastic. Green space will help—but only if one is rich enough to live in a lowerpollution area, and if one’s body (usually white, usually male) is not threatened regularly. Maybe some of these things will reduce your exposure. But this framing around individual product replacement is a scam for two reasons. First, this idea of personal responsibility tends to be gendered, falling in particular on women and gender-diverse people. Women often perform the labor of minding risks and trying to reduce them, and many studies of intergenerational harms are framed in ways that blame mothers for their own exposures. The second reason is that this individual framing misses out on the chance to notice the structural one. To see the structural problem clearly, it

helps to look back to a time when plastics were not widely disposable or a major source of pollution. In 1956, Lloyd Stouffer, then-editor of the magazine Modern Packaging, encouraged a room full of attendees at a conference of the Society of the Plastics Industry to start thinking about one-time

for the Society's annual conference reflecting on that talk and where plastics had gone. “It is a measure of your progress in packaging in the last seven years that this remark will no longer raise any eyebrows. You are filling the trash cans, the rubbish dumps and the incinerators with literally billions of plastics bottles,

The temptation so often when dealing with pollutants is to imagine an “away” where they do no harm. use plastics as the key to get continuing customers. “The future of plastics is in the trash can,” he said, meaning that disposable plastics would gain more consumers and make more money than multiuse plastics that one buys only once. In 1963, Stouffer wrote a review

plastics jugs, plastics tubes, blisters and skin packs, plastics bags and films and sheet packages—and now, even plastics cans.” He continued, “The happy day has arrived when nobody any longer considers the plastics package too good to throw away.”

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Wasted Reality

The Wasted Reality Arts Collaborative creates wearable trash art out of single-use plastics collected over one week in a person’s household. Single-use plastics were not the norm until the plastics industry began promoting them in 1956. 2021

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Effects of Exposing Endometrial Cells to Phthalates

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Phthalates and bisphenols, which are found in products and contexts such as those shown above, are implicated in endometriosis and endometrial cancer because both, as weak estrogens, can disrupt the natural estrogen-to-progesterone ratio in the body and therefore encourage extra growth of uterine tissue. A 2021 review in Reproductive Medicine and Biology found that exposing endometrial cells to phthalates causes inflammation, invasion, changes in cytokines, increased oxidative stress, cell viability, resistance to hydrogen peroxide, and proliferation.

Because that’s just it, isn’t it? The temptation so often when dealing with pollutants is to imagine an “away” where they do no harm. But as Max Liboiron of Memorial University in Canada says in their recent book Pollution Is Colonialism, there is no “away.” (For more on Liboiron’s work, see “How Climate Science Could Lead to Action,” January–February 2020.) People live near landfills; people rely on polluted waterways for food and income. Pollutants from landfills leach into groundwater. We are at the point where we have polluted our planet, affecting not just our species but entire ecosystems. In the early days of conservation efforts by settler scientists in the United States, researchers applied locational data on the Ohio River to our understanding of how pollution gets into 302

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• inflammation • oxidative stress • immune system molecules called cytokines • cell invasion and migration • cell viability and proliferation

(and supposedly out of) our water more broadly. They developed a threshold model, where there is a quantity of pollution you can pump into a river, under which the river can still recover. As Liboiron points out, both the eager corporate development of disposable plastics and the well-meaning conservationists’ threshold model assume one has access to Indigenous Land to put pollutants. Here, Liboiron does not just mean current tribal lands and reservations, but rather the land that was originally occupied by Indigenous peoples, and that settlers took from them. The assumption that this land is available to take and use as settlers wish, and that they consider some parts of the land acceptable for storing pollutants (to protect some but not

all people, places, and beings), undergirds the entire mitigation strategy of the United States. In other words, the disposable model from the plastics industry and the threshold model from conservationists are both permissionto-pollute models that never really asked permission. Pollution, then, is an ongoing and essential component of colonialism. “Colonialism is more than the intent, identities, heritages, and values of settlers and their ancestors,” Liboiron writes. “It’s about genocide and access.” And although endocrine disruptors are everywhere, they are unevenly distributed, causing additional violence toward Indigenous communities.

Max Liboiron

Max Liboiron’s 2008 interactive art installation The Dawson City Trash Project is a miniature diorama of the garbage sites in Dawson City, Canada, built from material found at those dumps. Because the garbage came from the community, people were allowed to take away any piece of it, symbolizing how a landfill disperses into people’s lives. People were generous in how they took pieces—for example, taking only one thing or taking something plentiful rather than a unique piece. Liboiron says people’s responses demonstrate alternative social economies outside of a market-driven system, ones where people are “generous, creative, and even daring in their relationship to each other and trash.”

When scientists participate in pollution science, or in a discussion, say, about phthalate exposure, we enable a process of what Patricia O’Brien, in her classic 1993 Professional Biologist article “Being a Scientist Means Taking Sides,” called assimilative capacity assessments rather than alternatives assessments. An assimilative capacity assessment would ask how much pollution scientists have decided the planet can tolerate, whereas an alternatives assessment would entail imagining a path where scientists and nonscientists together decide that no harm to people, other beings, or land is acceptable. As of now, most of the replacements for phenols and phthalates appear to be as bad, if not worse, than the originals. An alternatives assessment here is not as simple as replacing an ingredient. We need to reconsider the ubiquity of endocrine disruptors in our society as a whole. Taking this broader view, you could consider getting a menstrual cup (not everyone can tolerate them and it www.americanscientist.org

takes time to find the right one), and also teaching others to use them, because there is a significant learning curve. Maybe get a water filter if you can afford one (the ones that filter lead can be expensive), and also discuss with your local politicians about allocating more funds to your community’s infrastructure. Changing the frame allows us to see and act in solidarity across many communities and constituencies affected by the production, distribution, and dumping of polluting substances. What do you see when you change yours? Bibliography Clark, L. P., D. B. Millet, and J. D. Marshall. 2017. Changes in transportation-related air pollution exposures by race-ethnicity and socioeconomic status: Outdoor nitrogen dioxide in the United States in 2000 and 2010. Environmental Health Perspectives 125:097012. Eveleth, R. 2020. The best menstrual cup. Wirecutter. New York Times. (Updated December 11, 2020) www.nytimes.com /wirecutter/reviews/best-menstrual-cup

Hernández-Díaz, S., et al. 2013. Medications as a potential source of exposure to phthalates among women of childbearing age. Reproductive Toxicology 37:1–5. Iavicoli, I., L. Fontana, and A. Bergamaschi. 2009. The effects of metals as endocrine disruptors. Journal of Toxicology and Environmental Health, Part B 12:206–223. Kim, S. H., et al. 2015. Possible role of phthalate in the pathogenesis of endometriosis: In vitro, animal, and human data. The Journal of Clinical Endocrinology & Metabolism 100:E1502–E1511. Meeker, J. D., S. Sathyanarayana, and S. H. Swan. 2009. Phthalates and other additives in plastics: Human exposure and associated health outcomes. Philosophical Transactions of the Royal Society B: Biological Sciences 364:2097–2113. Rattan, S., and J. A. Flaws. 2019. The epigenetic impacts of endocrine disruptors on female reproduction across generations. Biology of Reproduction. 101:635–644. Richardson, S. S., et al. 2014. Society: Don’t blame the mothers. Nature 512(7513):131–132. Shadaan, R., and M. Murphy. 2020. EDC’s as industrial chemicals and settler colonial structures. Catalyst: Feminism, Theory, Technoscience 6:1–36. Wolff, M. S., et al. 2017. Associations of urinary phthalate and phenol biomarkers with menarche in a multiethnic cohort of young girls. Reproductive Toxicology 67:56–64. Kate Clancy is an associate professor of anthropology at the University of Illinois at UrbanaChampaign. She studies how environmental stressors influence menstrual cycle functioning, and is writing a book on periods for Princeton University Press called Life Blood: How the World Changed Menstruation. Twitter: @KateClancy, Website: kateclancy.com 2021

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Designed for Change Active products that adapt to fit users’ needs can be stronger, cheaper, and more comfortable than traditional, static objects. Skylar Tibbits

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ost products, just like pieces of infrastructure and much of the humanmade world around us, have one thing in common: They are designed to be stable and static. They are engineered to fight against all the forces around them—gravity, vibration, temperature, moisture, and so on. They are designed to be robust. They are generally not designed to be lean and adaptive, or flexible, or reconfigurable. Today’s products often don’t take advantage of their material properties and aren’t programmed to have any of the lifelike qualities that are possible with active matter. We compensate for the lack of adaptability or lifelike qualities in our products by creating so-called smart versions of them: smart thermostats, smart clothing, smart shoes, smart cars, and even smart bassinets that sense babies’ sleep patterns and adapt the sounds or motion accordingly. These smart products are often more expensive, heavier, and more complicated to build. They become easier to break and more difficult to use, and they consume more power. Our goal should be to make active products, by which I mean products, objects, or materials that can move, reconfigure, transform, assemble themselves, or adapt to their surroundings. To achieve active products, we need to reconsider the way we think and talk about our (statically designed) world. One of the fundamental principles of engineering has always been that any product or system ought to be designed to resist the forces that may lead to its

destruction—in other words, designing for robustness in the traditional sense. The result is that systems tend to be overengineered, and intentionally so. For example, various safety factors exist in buildings, bridges, cars, or planes to ensure that structures will withstand more than the weight we anticipate they will bear. Of course, this principle is extremely important for safety. But from a materials perspective, it’s wasteful. Perhaps it’s time that we rethink or expand what we mean by robust—and redefine smart in the process, too. A structure that is robust could also be active, lean, adaptable, and error correcting. A number of researchers have built morphing, self-adapting bridges and slab structures that can change dynamically as load is applied. These structures, although currently built electromechanically, demonstrate extremely lightweight and more materially efficient structures that can span and cantilever significant distances. They are one step closer to this dream of higherperforming structures with minimal materials while adapting to complex dynamic situations—without more components, more material, or more rigidity. In the end, less is smart: The more we can do with less, the smarter our systems will become. Built-In Flexibility The principle of error correction is critical to creating active products and structures. It allows us to ensure that accurate products are assembled in the factory, and it can also inspire us to design structures that improve over time. We can actively engage, enhance, and make the

most of this principle. The challenge is to figure out how to design for error correction in the products around us. We can start by looking for timeless design and material functionalities. Think of classic furniture, vintage cameras, or classic cars: The designs of these products have lasted through time and often still look as radical yet elegant today as they once did. Materials and functionality can last as well— and even get better. Concrete, counterintuitively, is a material that can grow stronger with age due to the hydration process and interaction of the material elements. We can imagine designing systems of all sorts—manufacturing, products, or environments—where we impart energy and just the right conditions to promote error correction and overall improvement over time. Natural systems exhibit characteristics of robustness and resilience—they are lean, soft, and agile, and can adapt to changes in their environment. These systems resist failure very differently compared with the ways we typically engineer systems. For example, bone grows with variable density and stiffness depending on its location in the body and the weight an individual carries. An astronaut’s bones will adapt and reduce their mass, and then regrow when they get back to Earth. Many natural systems, including our bodies, can regrow, adapt, and correct errors when needed. In other words, error correction itself is a form of robustness. To understand how error correction can work in everyday objects, let’s look at the simple example of building a circle. One manufacturing approach is to

QUICK TAKE Smart products don’t need to be hightech. Objects made with basic materials, such as rocks and string, can be more robust and adaptable than technology-heavy versions.

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Products made with active materials and techniques can adjust to changing circumstances, giving them the potential to be more reliable than their static counterparts.

Active textiles transform mass-produced clothes into custom garments that can adjust to different conditions to keep the wearer comfortable in various climates.

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Self-Assembly Lab, MIT/Google

This zigzag wall was built out of loose rocks and coconut husks using a technique called granular jamming, which allows disordered particles to transition from a liquid-like state into a solid-like state. This fast, efficient, and reversible method produces structures that grow stronger with use as the materials pack closer together, yet are flexible enough to adapt to changing conditions.

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Granular jamming creates structures that are strong, flexible, and reversible. Two members of the MIT Self-Assembly Lab construct a wall by evenly distributing loose rocks and string inside a wooden mold (above left). Structures made by this method are stable enough to be rotated flat, as demonstrated by the column-turned-beam (above right). Tightening the wooden boards at either end compresses the beam into an arch strong enough to walk across (opposite page, left). When no longer needed, the structure can be “switched off,” and the materials will fall back into their original forms: loose rock and string (opposite page, right).

make the components with extreme precision, with the exact angle needed for the exact number of parts. If you start to connect the parts with rigid and strong connections, you will need to build in some error tolerance. If the weather changes, or the moisture or temperature increases, the parts may become slightly larger or smaller than originally designed. The machine that was used to

A second approach is to build each part so it can pivot or flex where it meets the neighboring part—building error correction into the system. With flexible connections, as the parts of the circle come together, they adjust to one another. As the last part goes into the circle, all of the others can adjust their angles to create perfection. Adding simple flexibility in the connections

The jammed rocks and string behaved like a solid structure, but once we removed the top and bottom plates, it instantly dissolved, which meant that we could switch the structure on or off at any time. fabricate them and the materials themselves all have some amount of error tolerance. If you have just a few components, it might work. But as you increase the number of parts, tolerance propagates, and it is likely that the last part won’t fit perfectly. Even if the parts fit or can be forced together, fluctuations in the environment may create differential expansion or contraction, causing the circle to buckle or bulge. Every piece has only one place in the finished circle, and each one needs to be made with 100 percent precision to create the perfect circle. 306

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allows the circle to find its own equilibrium. When the environment fluctuates, these units will adapt and adjust, always maintaining the perfect circle. Flexibility serves as a form of error correction that provides us with more robust structures without adding more material or complexity to the design. Similarly, when we are assembling something with bolts, we are often told not to overtighten the first bolt. Rather, we hand-tighten all of the bolts and then go back around and tighten the rest. This process ensures that all of the bolts are

tightened evenly and are well aligned. Or when bolting a tire onto a car, it is recommended to follow a star pattern of tightening to ensure that the tire sits perfectly snug. If you overtighten one side substantially more than the other, then the initial side will be tightened off-axis. These simple techniques allow structures to have some flexibility and to self-align, falling perfectly in place without measurement or precise machines. Fast, Strong, and Reversible In my role as the founder and codirector of the Massachusetts Institute of Technology’s Self-Assembly Lab, I often strive for less material and less complexity in our designs, but there is also a case for material redundancy if we view the term in a different light. If you have more material than necessary, you can sometimes create a very simple system that may be fast, inexpensive, and easy to build. Think of a bird’s nest—it can be expediently assembled, often with a lack of precision. The geometric intricacy of the nest can be robust and create breathability and flexibility—features that a more rigid structure may not achieve. So we can sometimes counteract a lack of efficiency in material usage if we can increase speed, improve material placement, and decrease cost by using simple and imprecise components to create a robust and adaptable structure. The Self-Assembly Lab in collaboration with Gramazio Kohler Research at ETH Zurich developed a project that highlights this principle of material redundancy and adaptability: a system of granular jamming that uses rocks and string to create load-bearing columns or walls. Granular jamming is a material phenomenon that allows disordered particles to transition from a liquid-like state into a solid-like state and back again. Think of coffee in a vacuum-

sealed package: That package is typically very stiff and feels like a rock. But when you open the package, the coffee easily flows out. We took advantage of this principle; however, we developed a granular jamming system that doesn’t require a vacuum or a membrane. Given that membranes are susceptible to puncturing and vacuums are energy intensive, we wanted to find a new technique for granular jamming that could be used as a construction method. In order to build the jammed structure, we created an elegant balance of forces by depositing the right mix of loose rock and continuous string, layer by layer, within a bounding box. After a layer of rock was poured into the box, a robot unspooled a series of loops of string, then another layer of rocks, then string, and so on. When we removed the bounding box, only the rocks that were near the string got stuck, while the rest of the rocks fell away. The rocks couldn’t go anywhere when the bounding box was removed because the rocks took the compressive forces, and the string took the tensile forces, which made the structure jam into a solid object. This technique creates a load-bearing structure without using structural members, connectors, adhesives, or other binders. Our most recent approach to this research advanced our goal of letting the material do the work, making it as easy and fast as possible to build. In this latest version, we used a simple unspooling technique whereby a spool of string uncoils itself into perfect circles, the size of which depend on the spool and its height above the ground. This method uses off-the-shelf spools of string and replaces the precise robot deposition with a simple principle of physics: Let the string make precise patterns on its own. We then simply www.americanscientist.org

poured the rocks and unspooled the string to make columns and walls. Through granular jamming, structures can actually become stronger with load because the rock and string increasingly act more like a solid. We realized that if we used a top and bottom plate and compressed the structure with a threaded rod, we could jam it into solid structural components and move them around. We built a column and then rotated it into a beam or a bridge, as well as a wall that we rotated into a slab, and then we walked across the beam and slab structures. The jammed rocks and string behaved like a solid structure, but once we removed the top and bottom plates, it instantly dissolved, which meant that we could switch the structure on or off at any time. We could build these structures extremely fast, make them load bearing, and then instantly switch them off, so they fall away into a pile of rocks and string. Going one step further, we realized that if we continuously compressed the horizontal beam, it would start to morph, like a semisolid material, into an arch, which we walked across and loaded at various points. This exploration showed us the fascinating and strange ways that simple materials like rocks and string can behave: They can act like solids, semisolids, liquids, and even switchable devices with reversible properties. We can make extremely strong structures with minimal construction time, or soft structures that can be sculpted into shape. Each of these granular jamming techniques works only because of the redundancy of the material system. Because it’s not feasible to place and position every single rock (there were hundreds of thousands of rocks in the experiment), we can’t be certain that the connection of the rocks or the

location of the fiber is perfect. We can, however, employ rock and fiber in just the right amounts to ensure the stability of the structure. This type of redundancy can also make a robust system, even though we have very little control over the precision or the details. So rather than robustness being about more control and attempting to fight the forces of failure, as is the typical case with a structural beam or component, robustness can also be achieved through expedience of construction, and more materials yet less control over their placement. In this way, the system is working in harmony with the forces of compression and tension to get stronger. We are certainly using more material than necessary, but the construction process is far faster than if it involved manual placement or poured concrete. In other words, we can sometimes gain speed or performance by letting go of control in the process. Active Products With material capabilities and fabrication processes advancing rapidly, research teams are increasingly demonstrating a new class of products that are no longer static and passive. At the Self-Assembly Lab, we have created a number of examples of active products, such as a flat wooden sheet that jumps into a table, assembling itself from its flat-packed box; a shoe that forms itself, eliminating molding or manual forming in the factory; and a knit garment that adapts to the shape of the body and changes porosity and thickness to keep you comfortable in any environment. Underlying many of these examples is a technique we developed for transforming flat sheets into three-dimensional shapes. To do this, a piece of stretchable textile, such as Lycra, is initially pulled tight and wrapped around a plate. The 2021

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Christophe Guberan/Carlo Clopath/Self-Assembly Lab, MIT

Active shoes spring from a single, two-dimensional sheet into functional footwear. A piece of fabric is stretched taut and then printed with material of various thicknesses (above left) in a specific pattern (above right). When the fabric is released, it folds and curls into a shoe (bottom right). This process eliminates the many pieces and specialized skills normally required to make shoes.

prestretching process embeds and stores energy in the material, to be released later on. The pattern of stretch can also bias the final transformation. For example, if the textile is stretched in a uniform manner, it will shrink uniformly when released. If the textile is stretched more in one direction, however, it will undergo a greater shrinkage force in that direction when it is released. After stretching the textile, we add rigid or flexible material layers, such as nylon, on top of it. These layers embed the geometric information and pattern that will direct the precise transformation of the shape.

into a saddle-like shape called a hyperbolic surface. The pattern of the material can be used as a geometric code to promote complex surface transformations. This technique triggers the precise self-forming process, transforming an ordinary flat sheet of textile into a useful shape. We recently applied this technique to developing active shoes. Traditional shoe manufacturing is an example of an industry that produces static objects by manually assembling different parts: the uppers, insoles, outsoles, and other

The textile instantly jumped into its 3D shape, encoded with the shoe’s curvature to self-form into a foot-like shape. The type of material, the thickness of the layer, and the 2D or 3D pattern placed onto the textile all influence how it behaves next. If the material is rigid or thick, the layer will likely have greater force than the shrinkage of the stretch textile, and it will significantly constrain the material from transforming. To take advantage of the stretch textile force, the deposited layer can be flexible or thin in certain areas to add flexibility and allow for the 3D transformation. The 2D and 3D shape of the deposited layer also influences the pattern of transformation. For example, if you deposit a circle onto the textile and stretch the textile in a uniform way, then when you release it from the rigid plate, it will jump 308

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components. If we consider just the uppers, for example, there are usually quite a few components, such as the vamp, the outside quarter, the inside quarter, the strap, and more. Each of these components requires a significant amount of manual labor to assemble. The components need to be die-cut or laser-cut from leather or other materials. This cutting is one of the most complex and labor-intensive aspects throughout the entire process. If the shoe is going to be made out of leather, the parts need to be arranged on a piece of leather, keeping in mind that the right and left shoe need to go together. Natural leather has a different amount of stretch across the different regions of the piece, which

means that the various components of the shoe require a skilled hand for precise placement in order to meet all of the stretch requirements. After carefully cutting the components, someone needs to form, sew, glue, and assemble them. This process can take many people, many machines, and many minutes, depending on the complexity of the material and the shoe. The manufacturing of shoes is still today mostly a manual process even for the largest and most technologically sophisticated companies. Similarly, the design process is traditionally separate from the fabrication and manufacturing process. Even in the most recent advances of 3D industrial knitting for shoe uppers, such as Nike’s Flyknits, the final product is designed to be static, it is not customized to the user, and it requires manual bonding or assembly for the sole of the shoe. Only recently have design and manufacturing started to inform one another and blur the lines between conception and creation with active materials. The process of manually forming shoes is precisely what we targeted in a collaboration between our lab and product designers Christophe Guberan and Carlo Clopath. We wanted to see how we could simplify the assembly process by taking advantage of material transformations. To design an actively self-forming shoe, we had to identify the geometric code that we would print onto the stretched textile that would allow it to transform into a shoe. First, we stretched the elastic textile around a

Mass-Produced Tailoring Recently, we looked at the adaptability of our textiles to address changing functionality or comfort requirements while the product is in use. We wanted to go beyond just the shape change of a textile and create porosity change, with new functionality built directly into the textile from the filaments, fibers, and yarns all the way up to the garment. To accomplish this goal we worked in collaboration with the clothing company Ministry of Supply and other researchers on a project through an organization called Advanced Functional Fabrics of America. The first development was focused on a single-direction transformation, where the textile could transform only once and never again. This type of transformation was geared toward tailoring and creating customized products that fit an individual’s body. Typically, tailoring is only possible either by manufacturing a custom garment, which is often logistically complicated, expensive, and slow, or by manually cutting and sewing in a traditional tailoring process, which is often labor intensive and expensive. For these two reasons, mass-produced garments use standard sizes—such as small, medium, large, and extra-large—that don’t fit any individual perfectly. Similarly, www.americanscientist.org

Self-Assembly Lab, MIT/Ministry of Supply/Hills Inc./Mechanosynthesis Group, MIT/Iowa State University

rigid plate in a uniform manner. We then printed a polymer onto the stretched textile in a specific pattern. The textile was stretched in a uniform manner, and the material properties were kept constant while the design variable that we adjusted was the printed pattern. The printing process allows for custom patterns and complete control over the shape while testing it out; once a shape is defined, it can be laminated, bonded, sewn, or otherwise combined with the textile. We designed the printed pattern to create all of the curvature of today’s shoes with a single piece of textile wrapping the foot from the toe to the heel. We went through many iterations and tested patterns to promote the precise transformation. Ultimately, we identified a pattern, printed it onto the textile, and released it from the plate. The textile instantly jumped into its 3D shape, encoded with the shoe’s curvature to self-form into a foot-like shape. As an extension of this process, we also created the sole of the shoe by promoting further curvature and wrapping from the bottom up around the sides.

Active textile tailoring can give mass-produced garments a bespoke look and feel. Clothes made in factories come in standard sizes (such as small, medium, and large) that fit a range of people, but are not tailored to individual bodies. Active textiles use yarns with specific material combinations knit into geometric structures that contract when exposed to heat or moisture (bottom). Strategic application of heat transforms a loose sweater (top left) into a custom-fit garment (top right).

even the same product and same size can be completely different depending on what factory it came from. With our research, we showed that we could still mass-produce garments, taking advantage of the speed, scale, and efficiency of industrial knit textile manufacturing, yet we could activate garments to selftransform around the customer. There are a number of examples where companies are trying to mass customize textile products using industrial knitting, either flatbed knitting or circular knitting. The dream is that you

can go from a 3D body scan of the customer, and then directly manufacture a unique garment and ship it to the customer’s door. This process is extremely challenging logistically, however, because the custom program to run the knitting machine is not automated and because of the lack of dimensional precision in textile manufacturing, which makes this an unsolved problem. Our approach was to avoid the custom program and custom manufacturing challenges and focus on embedding the customization intelligence directly into 2021

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Climate-active textiles respond to external temperature and moisture levels so that the wearer is comfortable in a variety of environments. In an air-conditioned office, the fabric contracts to become dense and warm (left), but in a hot car it loosens to become lighter and cooler (right).

the textile, not the machine. This shift allows us to mass-produce standard-sized garments, but when they arrive at the store, the garment can be activated with heat or moisture and will then transform itself, adjusting directly to the customer’s body. In this way, the customer receives a uniquely tailored garment that fits perfectly, without the complexity and cost of custom manufacturing or cut-and-sew tailoring. This

printing, we can change materials at every “pixel” (which in this case is a stitch in the textile) in a 3D garment. By changing the materials in relation to one another, we can finely tune the various material properties, designing them to expand or contract based on external temperature or moisture changes. Natural materials such as wool or various polymer fibers will shrink with a certain temperature or

By changing the materials in relation to one another, we can finely tune their various properties, designing them to expand or contract based on external temperature or moisture changes. type of single-direction transformation will happen only once; the garment will not return to the original shape and won’t transform accidentally when the customer wears or washes it. It is only designed to adapt for their perfect fit. In the more recent developments of this research, however, we have been able to demonstrate reversible, bidirectional transformations of textiles that are designed more for climate adaptability, allowing the textile to transform based on fluctuations in the external environment or the customer’s body temperature. These approaches also utilize industrial knitting technologies where we can swap the fiber, filament, or yarns, on a stitch-by-stitch basis, across the entire garment. That means, much like multimaterial 3D 310

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moisture activation. We can then vary the knit structure, stitch by stitch, across the garment to change the way that the textile will move. A contracting zone can pull open certain pores, or lift a vent flap to adjust breathability. Some fibers will shrink, while others will bulk and expand in cross section. We can use these behaviors to transform the global shape of the garment, creating zones that are thicker or thinner for insulation, comfort, breathability, or better fit. With this development, we can create knit textile garments that adapt for thermal comfort: If someone walks from their warm and cozy house into the brisk, cold outdoors, their lightweight and breathable sweater can close its pores and get thicker to help insulate and warm their body. Or vice versa, if

they are in a cool air-conditioned office and they walk outside on a hot summer day, their garment should be able to open up and become more breathable and thinner, more lightweight, to help cool their body and keep them comfortable in both temperature extremes. This type of active, self-transforming textile garment is bidirectional and can continuously adapt, going back and forth, adjusting to the ever-changing temperature dynamics that we experience every day. Moving Out of the Lab Self-forming footwear and active textiles offer new perspectives on the agency of our materials, arguing for a more dynamic and ever-changing performance relationship with our products. Although some of these products currently exist only in the lab, not on the market, that is likely not because they are more difficult to produce or more expensive or less durable. Their scope is limited today mainly because manufacturers and consumer cultures haven’t yet made room for thinking about active products in this new way. But that will eventually change. These materials, unlike the static products of our everyday world, do not resist all forces; instead, they become highly active, take advantage of the forces around them, and make use of their inherent material properties. Products shouldn’t sit around passively—they should adapt to our needs, react to the environment, and push us to perform better and live healthier lives together. Skylar Tibbits is a designer and computer scientist whose research focuses on developing self-assembly and programmable materials within the built environment. Tibbits is the founder and codirector of the Self-Assembly Lab and associate professor of design research in the architecture department at the Massachusetts Institute of Technology. This article is adapted from Things Fall Together: A Guide to the New Materials Revolution by Skylar Tibbits, copyright 2021 by Skylar Tibbits. Reprinted by permission of Princeton University Press. Email: [email protected]

Flashback, 1890 First Women Members A major accomplishment in the early 1890’s was the Society’s induction of five women scientists—a truly remarkable breakthrough during a period when women studying and working in science and technology was extremely rare. The five pioneering women inducted into the Society included entomologist and illustrator Anna Botsford Comstock, zoologist and neurologist Susanna Phelps Gage, Harriet Groteclass Marx, botanist Julie Warner Snow, and mathematician Mary Margaretta Wardwell. (Photos left to right: Anna Botsford Comstock, Susanna Phelps Gage, and Julia Warner Snow.) A few noteworthy women members include Getty Cori, 1947 Nobel Prize winner in Medicine; Barbara McClintock, 1983 Nobel Prize winner in Medicine; Maria Goeppert-Mayer, 1963 Nobel Prize in Physics; Sally Ride, physicist and 1st American woman astronaut; and Jennifer Doudna, 2020 Nobel Prize winner in Chemistry. Today, 52% of Sigma Xi members are women.

“Nominate a woman of inspiration for membership who is making an impact on scientific research or engineering to continue the tradition of great Sigma Xi members.” Email: [email protected]

www.sigmaxi.org Robert R. Morris. 2011. Sigma Xi, The Scientific Research Society 1886–2011. Marengo, Illinois: Walsworth Publishing Company.

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The Scientists’ Nightstand, American Scientist’s books section, offers reviews, review essays, brief excerpts, and more. For additional books coverage, please see our Science Culture blog channel, which explores how science intersects with other areas of knowledge, entertainment, and society: americanscientist.org/blogs /science-culture. ALSO IN THIS ISSUE THE CONTAMINATION OF THE EARTH: A History of Pollutions in the Industrial Age. By François Jarrige and Thomas Le Roux. page 313 DO NOT ERASE: Mathematicians and Their Chalkboards. By Jessica Wynne. page 315

ONLINE On our Science Culture blog: americanscientist.org/blogs /science-culture Plastic Pollution and Land Relations Katie L. Burke reviews a new book by Max Liboiron, Pollution Is Colonialism, which urges that scientific practice take an anticolonial approach in order to become better aligned with Indigenous concepts of land, water, and ethics.

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Finding Hope in Community-Based Conservation Paul S. Sutter WE ALONE: How Humans Have Conquered the Planet and Can Also Save It. David Western. 310 pp. Yale University Press, 2020. $30.

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s an environmental historian with a deep interest in the history of conservation, I greeted David Western’s new book, We Alone: How Humans Conquered the Planet and Can Also Save It, with enthusiasm, hoping to learn cutting-edge lessons from a conservationist whose career has been marked by taking African peoples and communities as seriously as the animals with whom they share the landscape. Western is a renowned wildlife scientist and a pioneer in communitybased conservation who has worked for more than half a century in East Africa, with a particular focus on Amboseli National Park and the Maasai lands of the Kenya-Tanzania border region. At its core, We Alone is a deeply personal book that traces the arc of his intellectual evolution from a hunter to a wildlife ecologist and conservationist, and it examines the lessons that he has learned from Maasai herders and other African peoples who have made a living from the land while also conserving its resources. The book is at its best when it springs from Western’s own experience and expertise, his thoughtful positions, and his own learning across time. But grafted onto that story is another book, much more sweeping in its ambitions and less successfully realized—a book that hopes to explain, as its subtitle suggests, how humans conquered the planet and can also save it.

We Alone is divided into three parts. Part I, “The Roots of Our Success,” takes as its primary purpose an examination of how, over the past several hundred thousand years, the human species evolved, grew in number so successfully, spread across the globe, and came to dominate the planet. The exploration of this question is peripatetic, a bit too evolutionary in its orientation, and, in the end, not entirely convincing. Central to this section, however, and ramifying throughout subsequent sections, is the defining question of the book, a much more interesting one to my mind: “Why, at the pinnacle of our ecological success, did we begin to conserve some of the very species we had conquered?” Western recognizes that this impulse is a product of a certain moment in history, and of a certain privileged place in that moment, and he freely admits that his Maasai friends and informants, though conservation-minded in their own ways, do not share his modern conservation sensibility. In this way, he thoughtfully interrogates his own evolving conservation commitments, questioning the role they ought to play in responding to human domination of the planet, and he clearly recognizes that the Maasai have other interests and struggles. Part II, “The Human Age,” is the shortest section and purports to chart the more recent history of the epoch that some now call the Anthropocene and the forces of globalization that are driving it. Western explains many of the disturbing trends of this era, during which humans are diverting huge amounts of biological productivity to their ends and fouling their own nest (to use one of his favored metaphors). However, his discussion here is often quite derivative (he is overly fond of summarizing the many books he has read), and a bit too selective and superficial. He is also surprisingly fatalistic about these trends and at the

David Western, who grew up in Tanzania, started out in life as a hunter, but at age 14 he traded his gun for a camera, and as an adult he began studying and saving wildlife in the Amboseli game reserve on Kenya’s border with Tanzania. He is shown here holding a cheetah orphan. Photo courtesy of David Western. From We Alone.

same time sanguine that they may be our salvation. “Despite its leveling force,” he writes, “globalization is both inevitable and our best hope for bettering our lives and sustaining planetary health.” Part III, “Our Once and Future Planet,” turns to ostensible solutions— ways of managing the Human Age for greater human and environmental well-being. As with the previous two sections, this one is most satisfying when Western is talking about his own rich experience and wisdom as a practicing conservationist and the many challenges that we now face in conserving other species. Western founded and chairs the African Conservation Centre in Nairobi, and his other career milestones have included heading the international programs of the Wildlife Conservation Society, establishing Kenya’s Wildlife Planning Unit and directing Kenya’s Wildlife Service, and serving as founding president of the International Ecotourism Society. His leadership in communitybased conservation really shows in his complex understanding of the social and cultural challenges to be met in www.americanscientist.org

the world of species conservation, and in his recognition that social justice and human well-being are essential to success in conserving other species. Aware of the desires that many Maasai have for more comfortable and modern lives, he poignantly notes that “the rich world is expanding the meaning of conservation to include biodiversity and cultural heritage as the poor world is struggling to escape them.” But the solutions Western proffers often seem naively optimistic. They partake too much of species thinking (the “We” in his title) rather than contending with social conflict and division, and they often ignore the political and economic channels of power that have most profoundly contributed to the problem. Capitalism, for instance, as a powerful historical force and the engine of globalization, is all but ignored in this book. In the end, We Alone tries to do too much. It wants to be both a book about the history and prospects of ecological conservation in a radically changing world, and one that grapples with a set of sweeping historical problems that have led us into the Anthropocene and for which species conservation is only a small part of the solution. I wish Western had stuck with what he knows best, communitybased conservation and its future, for those are the most insightful and satisfying parts of We Alone. Western is admirably aware that modern wildlife conservation makes most sense to those in positions of modern material affluence. However, his solution seems to consist in bringing that level of material affluence to the entirety of the world’s population; he is confident that people’s values will then pivot to his form of conservation. He is to be applauded for linking conservation to development in this way, but in my estimation he has too much faith that development can solve the problems of global inequality and ease pressures on the global environment. Paul S. Sutter is a professor of history at the University of Colorado Boulder. His current book project is an environmental and public health history of the construction of the Panama Canal. His other books include Let Us Now Praise Famous Gullies: Providence Canyon and the Soils of the South (University of Georgia Press, 2015) and Driven Wild: How the Fight Against Automobiles Launched the Modern Wilderness Movement (University of Washington Press, 2002).

Addressing Global Pollution in a Capitalistic World J. R. McNeill THE CONTAMINATION OF THE EARTH: A History of Pollutions in the Industrial Age. François Jarrige and Thomas Le Roux. Translated by Janice Egan and Michael Egan. 459 pp. MIT Press, 2020. $39.95.

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he value of this idiosyncratic book rests primarily on three things, the first two of which are at odds with each other. First, it attempts to be synoptic and global in covering its topic—an admirable ambition, but one very imperfectly realized here. Second, it contains a wealth of specific information about French pollution history, most of which was previously unavailable to those who don’t read French. Third, it focuses particularly on the role of chemical industries, which deserves more attention from historians than it has received. The Contamination of the Earth: A History of Pollutions in the Industrial Age is a translation of a French edition published in 2017, authored by French historians who specialize in the environmental and social history of industrial France. Although one might harp on the fact that the book does not live up to its stated goal of providing a global view of modern pollution, I think it more appropriate to appreciate the authors’ attention to their home country. Most of what the book has to say about pollution history in Britain, Germany, and the United States has already been said in publications familiar to anglophone environmental historians. The attention given here to Russia, Japan, South Africa, Mexico, and other lands with significant pollution history is thin. But Jarrige and Le Roux—with the help of their translators, Janice Egan and Michael Egan—illuminate the history of French pollution more fully, and more insightfully, than anyone has done before in English. The translation has rendered the French text into smooth English. The authors, and their translators, insist on using the awkward-sounding plural pollutions to emphasize the diversity of substances and processes involved. 2021

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This photograph by Olya Koto shows a mural by street artist Pasha Cas on the side of an apartment building in the industrial city of Temirtau in Kazakhstan (see art by @Pashacas on Instagram). The project, which was curated by Rash X, has a Russian title that translates as Dancing (2016); it is reminiscent of Henri Matisse’s famous painting Danse and warns against idolizing the wealth derived from oil. In the background, the smokestacks of metallurgical plants emit lead pollution that reaches levels five times the authorized amount. The photo is reproduced in black and white in The Contamination of the Earth.

That usage has merit and deserves to catch on. Some references that perhaps needed no explanation in the French edition will probably be obscure to most readers of this one: for instance, the Leblanc process (for the manufacture of soda ash) and the Second Empire (which refers to the reign of Napoleon III, 1852–1870). Few readers outside the south of France are likely to know that Gardanne is a town of 20,000 people just north of Marseille. But with few exceptions, the translators have produced a readable, accessible text. The authors’ research, reflected in 83 pages of endnotes (but no bibliography), emphasizes both French- and English-language secondary sources. This is not an archivally based book that brings fresh information to light. Instead it organizes masses of information, reveals broad patterns, and provides access to those who do not read French to the findings and insights of the estimable francophone literature on pollution history. The structure of the book is broadly chronological. Part I treats early industrialization, 1700–1830, and is strong on the legal and regulatory responses to pollution in France and Britain. Part II covers the period from 1830 to 1914 and shows, among other things, how scientists, physicians, and the law 314

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worked to disarm critics of pollution, again mostly in France and Britain. Part III deals with what the authors call “The Toxic Age,” 1914–1973, a crescendo of contamination. It includes strong chapters on warfare, energy systems, and consumption as they relate to pollution. Nuclear contamination, oil spills, and air pollution from coal combustion come in for particular attention, as do the accumulation of plastic debris and the chemical wastes from mining and agriculture. Part III is less focused on northwestern Europe than are the earlier parts. The epilogue, which amounts to a full-scale chapter, brings the story up to 2017 and at last realizes the authors’ aim of a genuinely global approach to their subject. Merits of the book include its attention to changing and contrasting legal regimes. By and large, the authors contend, polluters have managed to get rules that allow them to avoid serious consequences for the damage they do. They have done so in different ways in different countries, but their success usually has involved finding and supporting scientists and other experts who were seeking to refute claims of ecological or health impairment, or at least to muddy the waters so no clear judgments could result. The example treated in greatest detail

here is the asbestos industry, which from the 1940s through the 1970s funded scientists and publications willing to deny, or at least cast doubt on, the fiber’s role in undermining human health. The authors excel at showing the degree to which such experts were, and are, creatures of their cultural and political contexts. Jarrige and Le Roux recognize how important military industry has been to the history of pollution. Early chapters show how entwined certain industries, especially chemical and metallurgical ones, were with military procurement in the 18th and 19th centuries. Governments frequently exempted the relevant industries from whatever limits to pollution did exist. During the protracted warfare between France and Britain, 1793–1815, governments did their best to liberate iron, chemical, leather, and other industries from any constraints, on the grounds that acidified rivers and toxic air were a small price to pay for a better chance at victory. Indeed, the political atmosphere of these wartime decades helped to “normalize” industrial pollution in these countries. These broad patterns continued into the 20th century, as shown in detail in the chapter on warfare since 1914. Environmental histories and histories of industry sometimes fail to take proper note of military institutions and the pressures they impose, but that is not the case here. The authors note, for example, that with 1967’s Six-Day War, the Israel Defense Forces became exempt from many environmental regulations. On a global scale, peacetime operation and maintenance of military machinery accounted for 6–10 percent of air pollution during the Cold War. The book also contains numerous details that I found educational and fascinating. I would not have guessed, for example, that in 1966 petroleum alone accounted for 53 percent of the total value of world trade, nor that today 10 percent of France’s electricity production goes to maintaining data storage centers, and especially not that, as of a few years ago, the energy consumed by one hour of humankind’s email traffic equals that of 4,000 round-trip airplane flights from Paris to New York. As far as I can tell, the authors made very few errors. Most are trivial. The least so (that I noticed) is that they mistakenly place Henry Ford’s develop-

ment of the Model T Ford and assemblyline methods of production in the 1920s. (Production of the Model T on a moving assembly line actually began in 1913, five years after the car’s debut.) The final message of the book is gloomy. The authors adhere consistently to what environmental historians call declensionism, meaning narratives in which things are always getting worse—and not just in the bad old days. In their view, the environmentalism of the past 50 years has met with minimal success. They maintain that when environmental movements seeking to reduce pollution demand that “economic decisions should be constrained by the planet’s ecological rhythms,” those movements are “invariably marginalized and ignored.” The root cause of enduring pollution, and the failure of efforts to check it is, in a word, capitalism. “Entrepreneurs insist on small individual gestures and good practices without ever calling into question the global organization of the world and its productive and consumerist model,” complain Jarrige and Le Roux. “While pollutions accentuate inequalities and global injustices, their regulation requires a radical reshaping of power and expertise.” I, however, would like to believe that replacing a fossil fuel–based energy regime with something more benign, and radically reducing industrial pollution in the process, can be achieved without the bloodshed and mayhem that the overthrow of capitalism might entail. Capitalism has proved durable, and the most successful efforts at countering it gave birth to the Soviet Union and Mao Zedong’s China, neither of which, as the authors recognize, did much of anything to check pollution. So if it is indeed true that large-scale reduction in industrial pollutions will require the abolition of capitalism, the odds appear sharply unfavorable— both because capitalism is hard to abolish, and because abolishing it would not guarantee a better result. J. R. McNeill is an environmental historian and University Professor at Georgetown University, and a former president of the American Historical Association. He is the author of several books, the most recent of which is The Webs of Humankind: A World History (W. W. Norton, 2020, 2 volumes), and is coauthor with Peter Engelke of The Great Acceleration: An Environmental History of the Anthropocene since 1945 (The Belknap Press of Harvard University Press, 2014). www.americanscientist.org

Chalkophilia Brian Hayes DO NOT ERASE: Mathematicians and Their Chalkboards. Jessica Wynne. With an afterword by Alec Wilkinson. 227 pp. Princeton University Press, 2021. $35.

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halk is the fossil fuel of modern mathematics. It was formed in the Cretaceous period, roughly 100 million years ago, when the seas swarmed with foraminifera and other planktonic organisms whose calciumrich skeletons accumulated in thick beds of the soft, white stone. Now the chalk is quarried, refined, and pressed into crayon-size sticks that mathematicians delight in stroking across smooth slate. A chalkboard is the preferred medium of expression for many kinds of mathematical discourse: solitary ruminations, teaching, presenting work to colleagues, collaborative research sessions. Do Not Erase presents more than 100 specimens of the mathematical chalkboard, in color photographs made by Jessica Wynne, who is on the faculty of the Fashion Institute of Technology in

Conspicuously absent from the images are the mathematicians who made all those white-on-black squiggles. No faces or hands stray into the frame. This austere aesthetic can be frustrating at times; we would like to see the artist behind the work, or better yet the artist at work. Nevertheless, I think Wynne chose the right strategy. She forces us to look at the chalkboards themselves, to see them as documents or artifacts, without the irresistible distraction of human presence. Among the unseen mathematicians are many celebrities, including five recipients of the Fields Medal, which is typically described as the mathematical equivalent of a Nobel Prize. But I am delighted to report that there are also lots of grad students and postdocs and junior faculty, whose blackboard scribblings are every bit as interesting as those of the illuminati. Wynne came to this subject not as an adept or an aficionado of mathematics, but through an accident of geography: Her summertime neighbors on Cape Cod are Amie Wilkinson and Benson Farb, mathematicians at the University of Chicago. One day she found it intriguing to watch Farb work for hours in his notebook on a complex problem.

Are we now living through the last great days of chalkboard culture? New York. Each photograph occupies a full page. The facing page holds a capsule biography of the mathematician whose work is on exhibit, and a few paragraphs of commentary or explanation. Some of the chalkboards were clearly produced specifically for the occasion of the photographer’s visit, but most of them are candid records of recent or ongoing work. The photographs generally show the entire board and little else—perhaps a chalk tray, an eraser, or the “Do Not Erase” placard that gives the book its title. For each photograph, the camera has been placed squarely in front of the chalkboard, accentuating its rectilinear geometry. As Wynne herself puts it, “I photograph in a literal, objective, straightforward way—showing the chalkboards as real objects—capturing their texture, erasure marks, layers of work, and all forms of light reflecting off their surfaces.”

Later she visited Jaipur, India, where she photographed elementary school blackboards filled with lessons in the Hindi language. Looking at the photos on her return, she was reminded of the mathematical symbols in Farb’s notebook. What the Hindi and the mathematics had in common was their inscrutability to someone from outside the culture. She was excited by these patterns that both drew her in and pushed her away, and thus was launched a project. She set up her tripod in departments of mathematics at two dozen American universities as well as a few institutions farther afield—in Paris and its suburbs, and in Brazil. “Inscrutability” is a word that may well cross the reader’s mind when looking at some of these images, where dense thickets of Greek and Roman letters sprout superscripts and subscripts. Often, however, there’s at least a hint of sense and substance, something for 2021

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The art of writing and drawing with chalk and the art of doing mathematics seem to be closely linked. In Do Not Erase, Jessica Wynne presents photographs of chalkboards created by more than 100 mathematicians. Many of them resist all interpretation, but this one, by Benson Farb of the University of Chicago, invites the viewer to try reconstructing what’s going on in the mathematician’s mind. A series of drawings all show three dots, enveloped in loops of pink or yellow chalk. Repeated transformations (labeled a and b at the upper left) twist the loop like taffy, but even in the final, intricate maze of folded loops, two dots are inside and the third remains outside.

the viewer to grab hold of—a revealing diagram, or perhaps a few lines of explanatory text amid the bristling equations. Blackboards were once standard equipment in all kinds of classrooms and academic environments. Chemists drew their molecules with chalk, and grammarians diagrammed their sentences. But most fields have moved on, willingly or not, to whiteboards or to PowerPoint. The mathematics community is the last holdout, clinging stubbornly to their dusty, distinctly old-fashioned chalkboards. The mathematicians quoted in this volume are proud of that recalcitrance. They praise chalk in terms of “tactile experience” and “sensual pleasure.” The chalkboard is a fluid and informal medium of expression, they say. If you change your mind about something, you can smudge out a symbol with the heel of your hand. Impermanence becomes a virtue. Nathan Dowlin of Columbia University writes that “on a chalkboard the idea can evolve gradually, the way it does in your mind. 316

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There is no pressure to get it perfect the first time, or even to get it right, since it’s going to be erased in an hour or two anyway.” On the subject of erasure there’s this further comment from Virginia Urban of the Fashion Institute of Technology: “A blackboard has a special quality— while incorrect or discarded ideas are easily erased, the haze is still visible as a reminder of the work that went into arriving at the solution.” Chalk is even praised for slowing the pace of mathematical work. When giving a “chalk talk,” a mathematician can go no faster than he or she can write equations on the board. Paul Apisa of Yale University explains: “A virtue of chalk, and talks that use it, is that it checks the Icarian desire of a speaker to communicate too much, heedless of the capacity of the listeners to comprehend.” A few of the comments even suggest that without chalk, mathematics itself might be in jeopardy. “The chalkboard is the glue that holds together this community and its rituals,” writes Nicholas G. Vlamis of Queens College of the

City University of New York. Benson Farb declares, “Chalkboards are a major part of my life. I couldn’t live without them.” In these statements I hear a note of anticipatory nostalgia, born of the fear that we are now living through the last great days of chalkboard culture. And it may be true. Natural slate boards are hard to come by, and the mathematicians’ favorite brand of chalk, called Hagoromo Fulltouch, was unavailable for a while a few years ago. The writing is on the wall, so to speak. Peter Woit of Columbia University takes an optimistic stand: “I’m willing to bet that a hundred years from now, mathematicians will still be using chalk and chalkboards.” I don’t share his confidence, but I do have faith that a hundred years from now mathematicians will have an effective way to communicate and collaborate, whether or not it involves fossilized foraminifera. Whatever the medium might be, I hope it can also provide those sensual and tactile satisfactions enjoyed by ardent chalkophiles. Perhaps it will even lend itself to a sumptuous book of fine photographs— assuming that medium survives. Brian Hayes is a former editor and columnist for American Scientist. His most recent book is Foolproof, and Other Mathematical Meditations (MIT Press, 2017).

Volume 30 Number 05

September–October 2021

Sigma Xi Today A NEWSLETTER OF SIGMA XI, THE SCIENTIFIC RESEARCH HONOR SOCIETY

New Term Begins for Distinguished Lecturers

From the President

With the start of the fiscal year in July, Sigma Xi welcomes in the 2021–2022 cohort of its Distinguished Lecturers. The 12 new and returning speakers were selected by the Committee on Lectureships to connect Sigma Xi chapters and members with science and engineering thought leaders. This year’s cohort of Distinguished Lecturers includes:

Sigma Xi has deep roots. The 2021 Annual Meeting and Student Research Conference, scheduled for November 4–7, will take place in conjunction with the Assembly of Delegates, which dates back to 1893. The long, rich history of the Society’s promotion of research excellence is well known, but the roots I have in mind run deeper still—the scientific virtues that ground the integrity of research practice. This year’s conference theme, Roots to Fruits: Responsible Research for a Flourishing Humanity, highlights these values and how they serve society. Deliberations about ethics and science are a regular part of Sigma Xi meetings and have stimulated my own participation. In Vancouver in 1998, I attended my first Sigma Xi Annual Meeting and gave a talk about justice and attribution of credit in research publications. In 2000, at the Albuquerque meeting, I organized a session on bioethics and gave a paper about how the virtuous scientist should address ethical concerns about human cloning. It was a small part of that year’s conference theme of New Ethical Challenges in Science and Technology. Such discussions help us make science better. Often the phrase “ethical challenges” in this context is used to suggest areas in which research or its applications may need to be curtailed or adjusted to avoid something that is morally problematic. This is important, but not doing harm is only part of the challenge. Ethics also challenges us to do good. This year’s theme of Roots to Fruits provides an opportunity to consider how to grow efforts toward the ideal. How can cultivation of the deep scientific virtues contribute not only to a flourishing research culture but also to the larger goal of human betterment? Conference tracks will focus on our responsibility as scientists in research and discovery, technology innovation, and STEM education. The lovely poster created for the conference (see inside back cover) illustrates the theme with the image of a tree. The fruits of science—discovery and innovation—are fed by the virtues that root the tree—curiosity, honesty, objectivity, and others. These values provide the integrity that gives the tree trunk its strength. The image also depicts some of the tasks that we must share as caretakers of the tree—watering its roots and pruning dead branches to maintain its vigor. The annual meeting is one venue where the scientific community gathers to contribute to this vital work. Registration for the conference is now open. I hope to see you there to help Sigma Xi continue to nurture the tree of science and its valuable fruits.

Julie Demuth National Center for Atmospheric Research

Andrew Fisher University of California, Santa Cruz

Agustín Fuentes Princeton University

Sir Christopher Lange State University of New York, Downstate Medical Center

Kristie Macrakis Georgia Institute of Technology

Oge Marques Florida Atlantic University

Heather McKillop Louisiana State University

David Pfennig University of North Carolina at Chapel Hill

Luisa Rebull California Institute of Technology

Federico Rosei Institut national de la recherche scientifique

Corinna Ross Texas A&M University–San Antonio

Danielle Wood Massachusetts Institute of Technology

Chapters and potential event hosts can book individual lecturers at sigmaxi.org/lecturers. Sigma Xi Today is managed by Jason Papagan and designed by Chao Hui Tu.

www.americanscientist.org

Of Roots and Fruits

Robert T. Pennock

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MEMBERS AND CHAPTERS

Sigma Xi Installs New Chapters at Whitworth University and Midwestern University On May 5th, a virtual ceremony was held to install the new Sigma Xi chapter at Whitworth University in Spokane, Washington. The ceremony was presided over by Sigma Xi’s Immediate Past-President, Sonya Smith. It was a celebration of the new chapter’s officers, members, and commitment to growth and advancement of the university’s research enterprise. Aaron Putzke, a professor in the biology department at Whitworth, leads the 10 founding members of the new chapter—faculty hailing from disciplines that include biology, chemistry, computer science, mathematics, psychology, communications, English, and education. In establishing the new chapter, the founders presented a three-year plan that includes recurring meetings, sponsorship initiatives, outreach, promotional events, and a STEAM Café lecture series. “The opportunity to expand our network, bring highprofile speakers to our campus, and present students with new grant opportunities, will strengthen and enhance our undergraduate research program,” said Putzke. “We look forward to growing our chapter and contributing to the outstanding reputation of Sigma Xi.”

On May 18th, Sigma Xi installed its newest chapter at Midwestern University in Glendale, Arizona. The inperson ceremony was presided over by Sigma Xi’s President Robert Pennock. John C. Mitchell, professor and associate dean for research at Midwestern, spearheaded the efforts of the university in its petition to form the new chapter. He will lead a group of 19 founding members through the initial years of the chapter’s development. As a medical and health sciences institution, Midwestern has a strong record of student-faculty collaborative research. The university is also well known for its public outreach programs. Mitchell anticipates that the new Sigma Xi chapter will enhance and support collaborative research, promote collegiality among fellow scientists, and provide a prestigious venue for presentation of science topics to both the institution and the public. The founding members presented a three-year plan that includes recurring meetings, sponsorship initiatives, lectures, and promotional events. The in-person ceremony included election of officers, a networking dinner, and a presentation of the official charter upon installation of the new chapter.

Grants in Aid of Research Recipient Profile: Nirmalya Thakur

Grant: $2,500 in Fall 2020 Education level at time of the grant: PhD Student Project Description: This project has aimed to develop a sensible and intelligent assistant (SIA) to help visually impaired people navigate and perform activities of daily living (ADLs) in an independent manner in pervasive living environments (such as Smart

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Homes). There are about 285 million visually impaired people worldwide, and they often need assistance in carrying out ADLs. Technology-based intelligent solutions are needed to assist living and improve quality of life. The project has aimed to explore and integrate the latest technologies from the fields of artificial intelligence, robotics, human-computer interaction, machine learning, pervasive computing, and related disciplines. It is expected to advance and contribute new knowledge to the research domains of activity recognition, human behavior, indoor localization, indoor navigation, and assisted living technologies. What is the most significant outcome of the project? The funding through the Grants in Aid of Research (GIAR) program helped support my ongoing research significantly. I developed a new computing methodology—

Pervasive Activity Logging (PAL)— that was presented in a paper at the 4th International Conference on Data Science and Information Technology in July 2021. PAL methodology can mine, study, track, analyze, and interpret the dynamic and diversified nature of both macro and micro components of user interactions during different and dynamic activities performed within the confines of a pervasive environment. PAL is expected to have multiple applications and use-cases to advance knowledge in the above-mentioned research fields in the next few years. Where are you now? I am currently working as an instructor in the Department of Electrical Engineering and Computer Science at the University of Cincinnati. I serve on the review board of many conferences and journals and have been the recent recipient of several research excellence awards.

PROGRAMS

Congratulations to the 2021 Student Research Showcase Award Winners Sigma Xi presented 10 monetary awards and 13 honorable mentions across three divisions in this year’s Student Research Showcase, an annual science communication competition. The virtual event included 274 student participants and more than 250 total presentations. First and second prizes were awarded in the high school, undergraduate, and graduate divisions, and top presenters were named in 13 disciplines. Additional prizes were given for the top overall winner of the competition and a people’s choice award, determined by public vote outside of the judges’ evaluations. The Student Research Showcase aims to build students’ science communication skills so they can convey the impact of their research to technical and nontechnical audiences. Participants submitted abstracts for entry into the competition in early spring. During a monthlong evaluation period, students built websites, videos, and slideshows to present their research to a panel of judges and public audiences. Judges’ evaluations were based on how well the students communicated enthusiasm for their projects; explained the significance of their research; used text, charts, and diagrams; and responded to questions.

Overall Winner – Harrison Ngue

Overall Winner ($500) sponsored by HappiLabs, Inc.

High School Division

Undergraduate Division

First Place – Undergraduate Division ($500) Harrison Ngue — Harvard University Cell Biology and Biochemistry Post-Transcriptional Regulation of Mitochondrial Ribosomal Proteins Confers Chemoresistance in Quiescent Cancer Cells

First Place ($500) Chloe Sow — The Downtown School Physiology and Immunology

Second Place ($250) Julie Lee — University of North Carolina at Chapel Hill Microbiology and Molecular Biology

People’s Choice Award ($250) Shrey Joshi and Ishaan Javali — Plano East Senior High School Geosciences GLAS: A Global Landslide Analytics System

Second Place – Tie ($250) Joseph Lee — Monta Vista High School Physiology and Immunology Ashwin Sivakumar — Flintridge Preparatory School Ecology and Evolutionary Biology Amith Vasantha — Basis Independent Silicon Valley Microbiology and Molecular Biology

Graduate Division First Place ($500) Sonia Patel — The University of Texas MD Anderson Cancer Center Physiology and Immunology Second Place ($250) Cori Fain — Mayo Clinic Graduate School of Biomedical Sciences Physiology and Immunology

Top Presenters by Discipline (Honorable Mentions) Selin Kocalar and Aylin Salahifar — Leigh High School and Carlmont High School Agricultural, Soil, and Natural Resources Harrison Ngue — Harvard University Cell Biology and Biochemistry Tyler Shern, Jessica Guo, Emily Zhou, and Varun Nimmigadda — Mission San Jose High School, Ward Melville High School, The Harker School, Novi High School Chemistry Ashwin Sivakumar — Flintridge Preparatory School Ecology and Evolutionary Biology Irfan Nafi, Eugene Choi, and Raffu Khondaker — Thomas Jefferson High School for Science and Technology Engineering Sonja Michaluk — Carnegie Mellon University Environmental Sciences

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Vanessa Swenton — Portland State University Geosciences Emilin Mathew — American Heritage School, Plantation Human Behavioral and Social Sciences Isaac Singer — Pine Crest School Human Behavioral and Social Sciences Mihir Rao — Chatham High School Math and Computer Science Julie Lee — University of North Carolina at Chapel Hill Microbiology and Molecular Biology Amanda Hao and Justin Hou — Aragon High School and Henry Gunn High School Physics and Astronomy Sonia Patel — The University of Texas MD Anderson Cancer Center Physiology and Immunology

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EVENTS

Sessions on Ethics and Scientific Integrity at Annual Meeting and Student Research Conference The theme of this year’s conference is Roots to Fruits: Responsible Research for a Flourishing Humanity. When we convene this November in Niagara Falls, New York, for the hybrid event, attendees will take part in compelling sessions that address scientific virtues, contemporary ethical challenges facing the research community, and social responsibility associated with scientific expertise. The following is a preliminary list of breakout sessions based on the conference’s theme, as well as other topics included in the professional development track. More sessions will be posted at sigmaxi.org/amsrc21. General Research Ethics Track Oral Presentation: Ethical Concerns with Advances in Medical Technology and Genetics — Subrata Saha, University of Washington Responsible Research and Discovery Track Virtual Workshop: Cultures of Excellence — CK Gunsalus, National Center for Professional & Research Ethics and Dena Plemmons, University of California, Riverside Responsible STEM Education Oral Presentation: Using Human Rights Issues to Engage Students in STEM Courses — Brian Shmaefsky, Lone Star College–Kingwood

Science Communication, Education, and Public Engagement Track Workshop: Responsibility: Where Science and Communication Collide — Allison Coffin, Washington State University and Kirsten (Kiki) Sanford, Science Talk Workshop: Paths to Science Policy Engagement in Your Local Community — Christopher Jackson, Engineers & Scientists Acting Locally Research Enterprise and Professional Development Track Workshop: Thriving When Facing Academic Politics — Noah Weisleder, The Ohio State University

College and Graduate School Fair Pursuing Solutions to Pressing Global Issues This year’s Student Research Conference will feature new interdisciplinary research categories focused on developing solutions for national and global challenges. Crucial issues such as climate change, cybersecurity, and vaccine advancement cannot be surmounted without engaging the innovative minds of today’s young researchers. Special Interdisciplinary Research Awards will be given to the top five students who have designated their presentations under one of the following categories: • Understanding the Universe (Astronomy and Space Sciences) • Biology and Biotechnology (Understanding the Brain, Origins of Life, Understanding Biological Systems) • Environmental Challenges (Providing Access to Clean Water, Mitigating Climate Change, Food Security, Sustaining Clean Air, Preserving Biodiversity) • Human Health (Advancing Drug Design and Limiting Drug Resistance, Advancing Health Informatics, Advancing Vaccines, Preventing Pandemics, Cancer Detection & Therapy) • Advances in Computation (Cybersecurity and Artificial Intelligence) • Design, Construction, and Manufacturing (Improving Urban Infrastructure, Advanced Materials, Making Solar Energy Affordable) • Critical Breakthroughs (Energy from Fusion) • Tools for Science, Education, and Personalized Learning • Human Sciences and Policy

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Sigma Xi Today

Are you an academic institution looking for a great way to connect with prospective STEM students? Register to be an exhibitor at the Sigma Xi College and Graduate School Fair! Held on November 6 as part of the 2021 Annual Meeting and Student Research Conference, this event invites colleges and graduate schools to showcase their programs to the best and brightest students interested in pursuing undergraduate or graduate degrees in science, technology, engineering, math, or health professions. 50% discount for institutions with Sigma Xi chapters. Visit sigmaxi.org/cgsf21 to learn more and register today!

November 4–7, 2021 sigmaxi.org/amsrc21