Tuesday, October 27, 2020

Taking math by storm: Talea Mayo models how climate change may affect our coasts

"I use a computer to solve math problems surrounding the way that fluid moves during storms," says Emory mathematician Talea Mayo. "I don't study the atmosphere. I study the response of the ocean to the atmosphere."

By Carol Clark

Talea Mayo joined the Emory faculty in May as assistant professor in the Department of Mathematics. A computational mathematician, she specializes in developing numerical hydrodynamic models to help predict coastal hazards.  

By creating models for storm surge caused by hurricanes, for instance, she is able to investigate the potential impacts of climate change on coastal flood risks. The resulting data may help policymakers and others develop better plans for the safety and resilience of coastal communities. 

Among Mayo’s accolades are an Early-Career Research Fellowship from the National Academies of Sciences Gulf Research Program and the Early Career Faculty Innovator Award from the National Center for Atmospheric Research. 

In the following Q&A, Mayo talks about some of the environmental forces that helped shape her as a scientist and as an educator, and how she became what she describes as “a fierce advocate of accessible, inclusive science and education of all people.” 

You grew up in Littleton, Colorado. What were some of your early math and computer science influences? 

My mom was in software development and we always had a computer around. I don’t ever remember not having one nearby. Before I even started school, she bought me this really simple kid’s learning tool that was like a computer, with a keyboard and a screen. By the time I was in first grade, she was teaching me multiplication and I would practice on my “computer.” 

I liked school and most of the subjects. I especially liked that math and science subjects were objective. Your answer to a problem is either right or wrong. But I really thought I wanted to be a lawyer. 

How did you decide to attend Grambling State University in Louisiana? 

I wanted to go away somewhere different than Colorado. I applied to a few schools randomly but I got a scholarship to Grambling and so I went there. I loved being in the South. It was so green while Colorado is so dry. Also, Colorado’s population is about 4 percent Black. My experience with Black people was mainly limited to church and family. Grambling is an Historically Black College and University and probably 96 percent Black. It was nice to meet Black people from all over the country and from all different socio-economic backgrounds. I played the flute and piccolo and I joined Grambling’s famous marching band. The band is really tight knit and that made it easy for me to build community there. I really value that. 

I also valued how the professors interacted with students. I was a criminal justice major, but I took a high-level calculus class because math was important to me. The professor eventually called me into his office and said, “You should change your major to math.” I thought about it and I realized that he was right, so I did. 

What prompted your interest in modeling the coastal effects of hurricanes? 

I was a sophomore in 2005 when Hurricanes Katrina and Rita hit the Gulf Coast. The university is in northern Louisiana and we didn’t deal with the storm surges, but I remember the rain. And a lot of students were from places along the Gulf Coast. That allowed me to see the personal impacts of hurricanes. One of the band members was from New Orleans and his sister was killed in a shelter. I realized that it was people who looked like me on the news, sitting on roofs, and seemingly not being taken care of. Seeing that societal impact, particularly for my community, sparked my interest in trying to do something about it. 

The following summer I got an internship at the National Center for Atmospheric Research. I worked on a project to try to understand the relationship between the intensity of storms and atmospheric water vapor. I realized how much I loved research and doing something beyond analytical math that had a practical application. 

You went on to become the first African-American PhD student at what is now known as the Oden Institute for Computational Engineering and Sciences at the University of Texas. What was that experience like? 

The transition was very difficult. Initially, I felt isolated within the institute as the only Black person. You may not even be conscious of it, but if there is no one that looks like you who is studying or teaching in a program, it’s like a silent message. I had to get up to speed in computational math, there was this big learning curve, and I also was dealing with culture shock. I couldn’t relate to people on a personal level and I was intimidated, thinking everyone else was so far ahead of me. It took me a while to get myself together and adjust. 

UT Austin is mid-way between Dallas and Houston and near Louisiana, so it was relatively easy for me to connect with people that I knew, which was healthy for me. And once I got into my research things got much better. I loved working with mathematical models and computer coding. I had a really great advisor. The day I defended my dissertation went as smoothly as it could have gone. The timing, the way I answered questions, the way the sun looked when I walked out of the building. That was a perfect day. 

The net was positive. My initial struggles in graduate school make me a better mentor now. 

How do you sum up your research? 

I use a computer to solve math problems surrounding the way that fluid flows during storms. I work with a model that doesn’t have to depend on historical data from storms in coastal communities. I can change a variable in the model and determine how that may affect a storm’s impact. One of the scenarios that I look at a lot is variables due to climate change. 

I don’t study the atmosphere. I study the response of the ocean to the atmosphere. Many people get focused on the category of a hurricane, which tells you the wind strength. But there is also the hazard from water, via storm surge and inland flooding. The water hazards also pose a great threat to the built environment. And human deaths from hurricanes are usually related to water. 

What improvements would you like to see in national hurricane research?  

The hazards are multi-dimensional so we should not study the problems underlying them in isolation. Katrina was catastrophic not just became of the storm but because New Orleans is below sea level, it’s densely populated, and there was a failure of infrastructure. And there are bigger questions than those surrounding physical infrastructure. How do we develop the social infrastructure needed so that low-income people can evacuate in an emergency? How do we foster resilience? 

We need more science in politics if we want to protect coastlines. We need truly inter-disciplinary teams tackling the problems funded over 20-year timescales, so we don’t just do things halfway. As a nation, we’re so reactionary. But only one dollar in prevention equals six dollars spent on a reaction. 

Why did you decide to come to Emory? 

The faculty here really care about teaching and so do I. The students are well-supported, especially in the Department of Mathematics. And I feel valued as a truly inter-disciplinary researcher. I don’t belong in a box. Emory offers a lot of opportunity to grow as my interests evolve. I can collaborate with faculty from the Department of Environmental Sciences, the Department of Computer Science, the Rollins School of Public Health and elsewhere across campus. 

What do you hope will be your academic legacy? 

I want to make an impact scientifically. I want to write good papers and to advance knowledge. And, at the end of the day, I hope that people will say, “She was kind. She treated people well while she achieved those things.”

Related:

The Georgia Coastal Atlas: A portal to hidden stories

Climate change calls for a fresh approach to water woes

Responding to climate change

Monday, October 26, 2020

New lead screening method zooms in on highest-risk areas in Georgia

Click here to see an interactive version of the map of priority screening index scores for low-level lead exposure in Georgia. Emory researchers, in partnership with health officials, are offering free soil testing of lead levels for Georgia residents through November 15. Click here for details.

By Carol Clark

While many people think of lead poisoning as a problem of the past, chronic exposure still occurs in some communities that may be missed in limited screening programs for children’s blood lead levels. Now researchers at Emory University have developed a more precise screening index, illustrated with a map, which provides a fine-grain view of areas where children are most at risk for low-level lead exposure in the city of Atlanta and throughout the state of Georgia. 

Scientific Reports published their new method, including analyses that tested and showed its efficacy, using historical data. 

The new screening index is based on established risk factors for lead exposure, including poverty and housing built before 1950. The index pinpointed 18 highest-priority census tracts in metro Atlanta, encompassing 2,715 children under the age of six — or 1.7 percent of all children that age in greater Atlanta. 

These highest-priority areas include the historically black neighborhoods of English Avenue and Vine City, where Emory researchers had previously identified elevated levels of lead in the soil of some yards and vacant lots. 

“As we move forward into an age when acute lead poisoning is rare, we need better tools to monitor for chronic, long-term exposure to lead,” says Emory graduate Samantha Distler, first author of the paper. “We developed an interactive map that can be used by physicians and other health officials, and even by individuals who want to check their own children’s risk levels. You can easily zoom in to find an exact location, so there’s less guess work involved in assessing what is a high-risk area.” 

The method could be applied to any area in the United States, she adds. 

Distler led the work as an Emory undergraduate majoring in quantitative sciences on the neuroscience and behavioral biology track. She is now a graduate student of epidemiology at the University of Michigan School of Public Health. 

“Lead is a toxicant that is particularly dangerous to children and their developing brains,” Distler says. “Even low blood lead levels are associated with neurological deficits in children.” 

“One of the biggest problems concerning lead is that many people don’t know if their children are being exposed,” says Eri Saikawa, senior author of the study and associate professor in Emory’s Department of Environmental Sciences and Rollins School of Public Health. “Detecting lead exposure as early as possible is very important so preventative measures can be taken. The easiest way to do that is to screen the blood.” 

The Saikawa lab is offering free soil testing of lead levels for Georgia residents through November 15, in partnership with the Georgia Department of Health, the Agency for Toxic Substances and Disease Registry and Georgia Adopt-A-Stream. Click here for details of how to collect a sample and where to drop it off. 

In 2018, the Saikawa lab collaborated with members of Atlanta’s Historic Westside Gardens to test urban soil on Atlanta’s Westside for contaminants. That project uncovered high levels of heavy metal and metalloids in some yards, and even some industrial waste known as slag. The project led to an investigation by the U.S. Environmental Protection Agency, which in 2019 began decontaminating properties in the area by removing and replacing soil. 

In addition to neurological deficits, lead exposure is associated with immunological and endocrine effects and cardiovascular disease. Decades ago, federal regulations reduced lead in paint and gasoline and other common exposure sources. The resulting drop in children’s blood lead levels in the United States is considered one of the greatest public health achievements in the country’s history. 

Many people remain unaware, however, that lead persists in the environment. “It can linger for a really long time in everything from soil to water,” Distler says. “That puts some people at risk for chronic exposures to low levels over a long time.” 

The Centers for Disease Control and Prevention (CDC) estimates that at least four million households in the United States have children living in them who are being exposed to high levels of lead. And about half a million of those children aged one to five years have blood lead levels above five micrograms per deciliter, the level at which the CDC recommends initiating public health action. 

Despite this alarming statistic, many children in higher-risk areas are not screened for blood lead levels. In Georgia, data from the period 2011 to 2018 show that the proportion in various ZIP code tabulation areas who have been tested range from 1 percent to 67 percent, with a median of 13 percent. 

The Emory researchers realized that one problem may be that health officials focus screening efforts on a county-wide basis, rather than zeroing in on the highest-risk neighborhoods within those counties. 

In 2009, a team led by researchers at the CDC developed and published a priority screen index for Atlanta neighborhoods based on housing age and percentage of residents enrolled in Georgia’s Special Supplemental Nutrition Program for Women, Infants and Children (WIC), a proxy for poverty. 

For the current paper, the Emory researchers built on the efforts of the 2009 paper, drilling down from neighborhoods to more precise U.S. Census Bureau tracts. Data from the American Community Survey was used to assess the relative level of poverty and proportion of homes built before 1950. 

A priority screening index, ranging from two to eight, was applied to the census tracts. The areas of highest relative poverty and proportion of homes built before 1950 received the highest score. The researchers applied this index to census tracts across the state of Georgia and to the entire United States to identify tracts that consistently have the highest priority screening index values. 

“The visualizations of our priority screening index that we’ve created using interactive maps can empower physicians and health officials to better target children at high risk for lead exposure,” Distler says. “We hope our work will help lead to improved policies and actions to reach children who are most at risk for lead exposure and to improve their lives — not just in Georgia but throughout the United States.”

Related:

Thursday, October 8, 2020

Leading a new era in ancient DNA research

A new ancient DNA lab at Emory is mapping little-explored human lineages, studying genetics of the deep past to better understand modern-day populations of the Americas.

Emory junior Rosseirys "Ro" De La Rosa is helping analyze DNA that she extracted from ancient bones unearthed in Uruguay — the remains of an Indigenous people known as the CharrĂșa. “Very few remains of the CharrĂșa have been found,” De La Rosa says. “They were largely wiped out by colonialism and a lot of mystery surrounds them. Anything that we can learn is important.”

It may be possible to connect the ancient CharrĂșa to modern-day populations unaware of their link. “Culture matters,” says De La Rosa, who is continuing to work on the project remotely this semester. “Leaning about your own culture gives you a sense of unity and connection that you can pass down to others.”

De La Rosa is a member of the Lindo Ancient DNA Laboratory, headed by John Lindo, Emory assistant professor of anthropology. The state-of-the-art facility, funded by major grants from National Geographic Explorer and the National Science Foundation, opened in January in Emory's Psychology and Interdisciplinary Sciences Building. It is one of the few in the world involved in every step of the complex process of solving mysteries surrounding ancient remains. 

"We build projects from the ground up," Lindo says. "We extract DNA from ancient remains here, sequence it here, analyze it here, and publish the results."

Most previous ancient DNA work involves people of European ancestry. A focus of the Emory lab, however is exploring how environmental changes — including those caused by European contact — affected the biology of Indigenous and other populations of the Americas.

"Our work can connect people to ancestries they potentially don't know about," Lindo explains. "It can also give them insights into how historic, and even prehistoric, events may be affecting them today, especially in terms of health risks and disparities."

Read the full story.

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Monday, October 5, 2020

Gender parity review of psychological science shows progress and problems

Emory psychologists Sherryl Goodman and Stella Lourenco were among the 59 researchers, from nearly 40 different institutions, who co-authored a review of gender parity in psychological science.
 
By Carol Clark

When Sherryl Goodman joined Emory’s Department of Psychology in 1977, she was the sole female member of the faculty. “I was typically the only woman in the room,” recalls Goodman, now Samuel Candler Dobbs Professor Psychology. 

Things have changed over the decades, both nationally and at Emory — where the percentage of women faculty in the Department of Psychology is approaching half. Despite the great gains in numbers of women in the profession, much more work is needed to achieve true gender parity, Goodman says. 

Goodman and Stella Lourenco, Emory associate professor of psychology, are among the authors of a report on gender parity in psychological science, based on an extensive review of peer-reviewed studies. Perspectives on Psychological Science published the review, entitled “The Future of Women in Psychological Science,” co-authored by 59 researchers from nearly 40 different institutions from across the United States, Canada and Australia. 

The authors found that women are attracted to psychology in record numbers and earn more doctoral degrees in the field than men. And women who choose to enter the academy as assistant professors of psychology are even more likely than men to get hired and are as likely as men to obtain tenure. They also found, however, that women are less likely to apply for tenure-track positions. And fewer women attain the rank of full professor than men. 

Women also remain underrepresented in more senior ranks in psychology departments and they are less likely to receive salaries comparable to those of men in these senior positions. And women across their careers are less likely to submit, renew and hold grants or to have publication and citation rates comparable to their male colleagues. 

“When I was a graduate student, my adviser used to tell me about the gender discrimination she faced as a woman in science and how I had it so much better,” recalls Lourenco, who joined the Emory faculty just over 10 years ago. “She was right. There has been much progress in the field. At the same time, there is still much more to do.” 

Some well-intentioned policies may have even backfired for women, Lourenco notes. For instance, parental leave is now available for both female and male faculty. “There is evidence that men may benefit more from parental leave than women, with relatively more publications than their counterparts at institutions without parental leave,” she says. “To be sure, parental leave is a good thing. But if women take on more of the burden of childcare, they will publish less than men on parental leave. Institutions need to be aware of such issues when later evaluating women for tenure and promotion.” 

The review cites a 2016 survey in which U.S. mothers reported spending 75 percent more hours per week on childcare than fathers did. 

Academic careers are still not seen as “woman friendly,” Goodman notes. “We still lose a number of talented Ph.D. graduates who don’t even bother applying because they don’t see viable careers in academics for women. That’s sad and a loss to the field of psychological science, and to the academy more broadly,” she says. 

Among the recommendations that the review urges universities to consider are: Offer high-quality, affordable childcare; supplement the cost of egg freezing to expand women’s fertility windows; and provide support through more partner hires or benefits packages that include employment for a spouse outside the university. 

The authors also called for enabling women to improve salary negotiation skills and for greater transparency related to compensation. They cite a 2018 National Science Foundation report that found, across all institutions, women’s full professor salaries were 88 percent that of men, and their associate professor salaries were 92 percent that of men. 

The review focused on women in general in psychological science, while noting that women of color and people who are a minority in terms of gender orientation face extra challenges that also need to be addressed. 

Although the review did not include the impact of COVID-19, the pandemic highlights the problem of gender disparity more broadly, Goodman says. 

“Women tend to share more of the burden of taking care of a family, and suddenly, many of them also had to become teachers of their children,” she says. “The pandemic compounds the impact of an already existing problem. It may be another factor that causes some women to have to opt out of the workforce or to become less productive in their jobs.” 

The review authors sum up their findings in a concluding statement: “The need to address the issues facing women in psychological science coincides with a particular cultural moment in U.S. and global social history, one in which women are speaking out and taking action in an unprecedented way to address sexual harassment, financial and social inequality and gender biases. As a field committed to the science of equality, psychology has the opportunity to lead other disciplines in how best to create and maintain a culture of inclusion.”

Related:

Tuesday, September 22, 2020

'Firefly' method makes cellular forces visible at molecular scale

The image on the left shows the force activity of a cell at a resolution of about 250 nanometers. The image on the right shows how much clearer the image becomes with the resolution of 25 nanometers that is now possible with the new technique. (Microscopy photos by Alisina Bazrafshan)

Scientists have developed a new technique using tools made of luminescent DNA, lit up like fireflies, to visualize the mechanical forces of cells at the molecular level. Nature Methods published the work, led by chemists at Emory University, who demonstrated their technique on human blood platelets in laboratory experiments.

"Normally, an optical microscope cannot produce images that resolve objects smaller than the length of a light wave, which is about 500 nanometers," says Khalid Salaita, Emory professor of chemistry and senior author of the study. "We found a way to leverage recent advances in optical imaging along with our molecular DNA sensors to capture forces at 25 nanometers. That resolution is akin to being on the moon and seeing the ripples caused by raindrops hitting the surface of a lake on Earth."

Almost every biological process involves a mechanical component, from cell division to blood clotting to an immune response. "Understanding how cells apply forces and sense forces may help in the development of new therapies for many different disorders," says Salaita, whose lab is a leader in devising ways to image and map bio-mechanical forces.

The first authors of the paper, Joshua Brockman and Hanquan Su, did the work as Emory graduate students in the lab. Both recently received their PhDs.

Read the full story here.

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