Spring 2019 -- Consequences of Maladaptive Perfectionism

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Carolina Scientific

scıentıfic Spring 2019 | Volume 11 | Issue 2

Consequences of Maladaptive Perfectionism —FORESEEING THE FUTURE OF EATING DISORDERS— full story on page 10 1

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Work for Carolina Scientific!

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If you are interested, please contact carolina.scientific@gmail.com Find us on facebook facebook.com/CarolinaScientific Follow us on twitter @UNCSci Check out our website carolinascientific.org

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scÄąentific Mission Statement: Founded in Spring 2008, Carolina Scientific serves to educate undergraduates by focusing on the exciting innovations in science and current research that are taking place at UNC-Chapel Hill. Carolina Scientific strives to provide a way for students to discover and express their knowledge of new scientific advances, to encourage students to explore and report on the latest scientific research at UNC-Chapel Hill, and to educate and inform readers while promoting interest in science and research.

Letter from the Editors: The world is changing faster than we can comprehend.

The rate at which scientific knowledge is being produced and technological advancements are changing society is only accelerating. In this issue of Carolina Scientific, we invite you to pause for a moment and dive into a snapshot of the incredible scientific research taking place around UNC-Chapel Hill. In this issue, you can read about what tree rings can reveal about climate patterns (page 12), about the mysterious lives of hydrothermal vent microbes (page 16), and about physical activity and its relationship with cognitive decline (page 24). We hope you enjoy!

- Esther Kwon and Adesh Ranganna

on the cover

Executive Board Editors-in-Chief Esther Kwon Adesh Ranganna Managing Editor Akshay Sankar Design Editors Alexandra Corbett Associate Editors Janet Yan Ricky Chen Sara Edwards Marwan Hawari Andrew Se Copy Editor Aubrey Knier Treasurer Elizabeth Smith Associate Treasurer Sidharth Sirdeshmukh Publicity & Fundraising Chair Sophie Troyer Online Content Manager Rhea Jaisinghani Faculty Advisor Gidi Shemer, Ph.D. Contributors Staff Writers Violet Beaty Sara Bernate Megan Butler Mehal Churiwal Sara Edwards Kaia Findlay Lauren Gill Harrison Jacobs Madison Miller Divya Narayanan Janie Oberhauser Sophie Troyer Janet Yan Zelong Yin

Illustrators Tatiana Gonzalez-Argoti Taylor Thomas Laura Wiser

Copy Staff Aneesh Agarwal Anna Arslan Sara Bernate Coleman Cheeley Peter Cheng Elizabeth Coletti Robert Fisher Candice Greene Jie He Divya Narayanan Designers Sidharth Sirdeshmukh Elizabeth Coletti Melanie Stewart Brianna de la Houssaye Zarin Tabassum Tatiana Gonzalez-Argoti Sophie Troyer Taylor Thomas Wilfred Wong

Researchers look into the factors that influence eating disorders and anxiety. The findings may help to better predict who is at risk and to make better potential treatment plans.

Full story on page 10. Illustration by Tatiana GonzalezArgoti.

carolina_scientific@unc.edu carolinascientific.org facebook.com/CarolinaScientific @uncsci 4

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Public Health 6

contents

Technology and Innovation

Moms Matter: Stepping Up Research on Motherhood

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Practice to Policy: Stregthening Public Healthcare Systems

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Foreseeing the Future of Eating Disorders

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Megan Butler

Violet Beaty

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Ecology

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Paint Your Lung with Hyperpolarized Gas Zelong Yin

Lauren Gill

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Running Shoes and Parkinson’s Disease Divya Narayanan

Janet Yan

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How Pelicans Can Teach Students to be Data Scientists

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Individualized Injury Prevention

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The Waltz of Subatomic Particles

Janie Oberhauser

Written in Rings Kaia Findlay

‘Laying’ the Groundwork for Ecological Research Sara Bernate

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Our Oceanic Secret Saviors

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Air Pollution and Climate Change

Harrison Jacobs

Medicine and Health 32

Sophie Troyer

Chemistry Links Metabolism and Medicine Madison Miller

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Sara Edwards

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Silent Attacks

Mehal Churiwal

public health

Illustration by Laura Wiser

MOMS MATTER Stepping Up Research on Motherhood

By Violet Beaty

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The goal of this project is to surround moms with a “village” of support in every form. The 4th Trimester Project actively strives to bring postpartum maternal care into the spotlight and is centered around the experience of minority and underserved moms. They work in many ways to accomplish their goals, partnering with individual moms, reaching out to clinicians, and bringing these public health issues to politicians and the media. They not only want to be a voice for moms, but also provide a space for moms to share their experiences. Dr. Verbiest shared that “mothers often opt to suffer in silence for fear that they aren’t ‘normal’.”1 It is through facilitating conversations among women that this group of moms hopes to normalize conversations about the difficult parts of motherhood such as emotional and physical pain, depression, anxiety, and isolation so that women do not feel ashamed or embarrassed about their mental, physical, and emotional experiences.

The research compiled by this group of mom and baby advocates indicates that a new approach to motherhood must be developed, guided by a few key findings:

ehind every new baby is a new mother who has just as much to learn as her little one. With few accessible or relevant resources to turn to for support about her health and wellbeing it is pretty clear that most mothers have to go it alone on one of the toughest journeys a woman faces. 1.6 million moms do not receive a postpartum follow up doctor’s visit and 85% of new moms who reported feelings of postpartum depression do not seek help.2 Thankfully, groups such as the 4th Trimester Project, a partnership between UNCChapel Hill’s Jordan Institute for Families and the Center for Maternal and Infant Health, are working to change the statistic and bring the challenges of motherhood to light. This is a “mom for mom” partnership that centers motherhood around both mom and baby as a singular and inseparable unit.

Dr. Sarah Verbiest is a clinical associate professor in the UNC-Chapel Hill School of Social Work who earned her DrPH, MPH, and MSW from UNC. She has two children named Kylie and Tai and a supportive partner named Dirk. She is an avid runner, activist, and mom. It is the latter of these identities which drives her to advocate for maternal and child research and support. She is one of the team members striving to provide new moms with support through the 4th Trimester Project, a partnership between the Jordan Institute for Families and Center for Maternal and Infant Health which aims to change the way America treats new moms. As Dr. Verbiest stressed, this is a project centered on and “fueled” by moms.

1. Postpartum care is too little, too late for many women.

2. Postpartum health care, education and services should be tailored to women’s experiences, preferences and con straints.

3. Active listening, strengths-based approaches, and shared

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Figure 1: Concerns which the 4th Trimester Project team is working to investigate. Image courtesy of Dr. Sarah Verbiest and the 4th Trimester Project.

public health

Figure 2: The 4th Trimester Project Team at work. Image courtesy of Dr. Sarah Verbiest. women feel like they have to make it work on their own.

Research in the maternal and infant care field must expand in order to address the concerns of real women who want to know more about what to expect from their postpartum experience. Groups such as the 4th Trimester Project are working hard to not only find funding for such research, but also to ask tough questions that will guide researchers towards discovering valuable information to help moms. Allowing women to be at the heart of the discussions which concern their health and that of their babies is important in restructuring the way in which postpartum care is approached.

Moms deserve more knowledge about what is happening to their bodies after having a baby. They can only have access to such information if more funding and interest is directed towards understanding the complexities of the issues that women face. Dr. Verbiest and the 4th Trimester interdisciplinary team are working to find funding to explore the most pressing topics which new moms face. According to Dr. Verbiest, it is important to “listen to the issues which women are struggling with right now and work to address those.”1 Mainstream research provided in the expecting and new mom selfhelp books just does not address the real-life everyday problems moms have to face.

The 4th Trimester Project is striving to bring new and innovative knowledge to moms in order to allow them to restructure the way in which they approach their lived experience as moms. Research in the fields of public health, women’s health, infant health, emotional health, and mental health need to be revamped and pushed to the top of the list of priorities. Additionally, information on postpartum care must become more accessible and relevant in order to best benefit the needs of modern moms. After all, where would we be without our moms?

decision-making are essential.

4. Healthcare should be compassionate, equitable and cul turally sensitive.

These themes address many of the experiences most new mothers have. Women collectively seem to feel that they are unprepared for the toll of motherhood on their bodies, minds, and families. Women have inadequate knowledge about their changing bodies, inadequate work place treatment, and inadequate resources to make the transition into motherhood less trying. By identifying these key overarching issues that are apparent in many women’s experiences the 4th Trimester Project has the information necessary to begin to combat these problems directly.

Many of these issues deal with things that are hard to talk about. One such issue is that one in four women are obligated to return to work only 10 days after having their baby or they could face unemployment. 58% of expecting and new moms leave their job due to the fact that their employers do not meet their needs.2 Furthermore, and unsurprisingly, the biggest concerns most women have to deal with surround the intimate emotional and mental tolls a new baby can bring.

Moms do not want to talk about the feelings of unimportance and neglect they often feel when all of the attention shifts from them to the baby once delivered. They also do not want to admit that they are overwhelmed and sometimes challenged to balance care for themselves, their families, and their new babies. Because of the lack of discussion about the topic of motherhood and the lack of investment in Dr. Sarah Verbiest research about moms,

References

1. Interview with Sarah Verbiest, DrPH, MPH, and MSW. 2/5/19.

2. The 4th Trimester Project. https://jordaninstituteforfamilies.org/innovate/the4thtrimesterproject/ (accessed February 5th, 2019).

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Practice to Policy

Strengthening Our Public Healthcare Systems

By Janet Yan

Image courtesy of Creative Commons

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difficulties in dealing with competing priorities.1 As a result, she “[feels] much more grounded in the work that needs to be done in local, state, and national agencies” and is able to “connect researchers to the practice more effectively.”1 Conversely, as an academic, her partnerships with public health agencies allow her to “take what they do in [academia] and bring it into the community to improve people’s lives and community well-being.”1 Dr. Cilenti’s interest in MCH stems from its focus on “[intervening] early with women of childbearing age, infants, and young children to set the trail for their lifetime health,” because “repeated exposures to risk factors that can worsen your health accumulate over a lifetime.”1 Dr. Cilenti frequently engages with Title V agencies, organizations at the state level that receive federal grants to work on issues related to MCH, through her role in directing the National Maternal and Child Health Workforce Development Center based in Gillings. With a “focus on health equity and engaging families and communities,” the Center aims to build capacity among public Dr. Dorothy Cilenti

imited funding, countless issues to address, competing priorities, a volatile political climate – these are all difficulties that government and state-funded public health agencies encounter. To make the best use of their resources, many turn to evidence-based solutions that can be implemented to fit their communities’ specific needs in addition to training their workforce to have the necessary skills that are crucial to the success of the organizations and their initiatives.

Dr. Dorothy Cilenti, an associate professor in the Department of Maternal and Child Health (MCH) at the Gillings School of Global Public Health, works closely with local, state, and national public health agencies to provide training for public health professionals and contextualized implementation support. Through her extensive past and current involvement with the state and various local health departments, she has come to define governmental public health as “the cornerstone for our public health system.”1 In addition to having worked in the Division of Public Health within the North Carolina Department of Health and Human Services, she served as the health director for several counties in North Carolina, overseeing the operations of the health department, identifying health issues of the county and how they’ll be addressed, and engaging various stakeholders to work toward a common goal. Through her experiences as a public health practitioner, Dr. Cilenti developed an “understanding of what it [meant] to work in government and deliver these services,” including the

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Figure 1. (Left and right) Dr. Cilenti at a learning institute with public health practitioners. Images courtesy of Dr. Dorothy Cilenti. health practitioners and provide coaching and consultation the social determinants of health to observe how they vary services to assist Title V agencies in “[promoting] high qual- geographically and to determine “which populations are beity evidence-based health systems” and implementing health ing disproportionately impacted by poor health outcomes.”1 transformation.1 Typically, a state will reach out to the Center They look at twelve different factors, including access to prowith a particular challenge, such as “implementing develop- viders and availability of healthy foods, along with the intermental monitoring and screening to identify children with ventions to determine whether the root causes of poor health special needs.”1 The Center will be involved in several ways, outcomes are being addressed effectively.1 including performing needs assessments, observing grants Throughout Dr. Cilenti’s work, there is a clear commitreviews to determine capacity needs, training practitioners, ment to using evidence in approaching and solving public and providing technical assistance. Additionally, they have a health issues. As part of the Strengthening the Evidence inirobust evaluation system, where they interview the agencies tiative with Georgetown University, Dr. Cilenti and the Center at various time points and regularly “[use] the feedback to im- consolidate research into an “evidence repository based on a prove their services.”1 set of measures that are required to While Dr. Cilenti oversees partbe included in grants.”1 Using this nerships with many different states evidence, they are able to efficiently as part of the Center, one of her more determine best practices and further local research projects focuses on improvide implementation support. As proving community health outcomes Dr. Cilenti says, “it’s not enough to in women and children in five comjust figure out what to do, it’s how munities across North Carolina. With you do it in your context effectively.”1 their funding appropriated by the With much of her work instate, the projects “pilot implementavolving the training of public health tion of evidence-based strategies in practitioners, Dr. Cilenti recognizes communities where there are high the importance of building capacinfant mortality rates and children’s ity among students and finds workhealth outcomes are not where they ing with them to be energizing. She need to be.”1 Dr. Cilenti and her feltries to design her courses with an low researchers provide implementaapplied focus, integrating case studtion support, collect data, and then ies and real-world challenges, and use these data to drive improvement. They discuss important connect students with practitioners through their practicum questions with the community collaboratives: what’s working, or research opportunities. For students hoping to go into the what’s not working, what do these data mean in the context field, she notes the importance of understanding and enof the community, and how can they do better? As with many gaging communities, as well as building one’s network and of Dr. Cilenti’s projects, there is an emphasis on health equity; seeking opportunities to “gain exposure to community-led the projects use a health equity assessment tool to determine initiatives.”1 Moving forward, Dr. Cilenti hopes to write up and whether the interventions are improving outcomes without publish data that have recently been collected to “build the leaving any groups behind. For example, although the ma- science” and contribute to strengthening existing evidence or ternal mortality ratio in NC is decreasing overall, this may be identifying new evidence-based strategies. a result of a decrease in maternal mortality in black women and an increase in maternal mortality in white women.1 Along References with the NC Institute for Public Health, Dr. Cilenti also maps 1. Interview with Dorothy Cilenti, DrPH. 02/08/19.

“The Center aims to build capacity among public health practitioners and provide coaching and consultation services to assist Title V agencies in ‘[promoting] high quality evidence-based health systems.’”

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Foreseeing the Future of Eating Disorders

By Lauren Gill

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ith new research, we may now be able to predict when someone will get an eating disorder. In research labs around the country, studies are search for causes of the ever-growing epidemic of eating disorders and work to develop better treatment and prevention plans.

These are becoming increasingly important as eating disorders become more frequent (Figure 1). These research studies focus on many kinds of eating disorders, like anorexia nervosa, bulimia nervosa, binge eating disorder, and eating disorders not otherwise specified. They also investigate potential causes for these disorders, with theories ranging from genetics to upbringing to personality traits.

One such study occurred at UNC-Chapel Hill in 2017

by Dr. Anna Bardone-Cone. Dr. Anna Bardone-Cone, a professor and researcher at UNC-Chapel Hill, conducts research on a variety of psychological topics. She is currently working on 5 research projects, most of which relate to eating disorders.

Bardone-Cone’s team researched perfectionism and contingent self-worth in relation to eating disorders and anxiety. As many know, certain mental illnesses and disorders, such as depression and anxiety, are often comorbid, or occur simultaneously. Bardone-Cone’s research looks at the comorbidity of perfectionism, eating disorders, and anxiety, and the results are intriguing.

In this study, which aimed to discover if perfectionism could predict eating disorders and anxiety, undergraduate females were studied. Participants’ ages ranged from 17 to 24, and 69.1% were Caucasian/White.1 Their average BMI, body mass index, was 22.27. Though eating disorders do occur in men, Dr. Bardone-Cone only included women in her study “because there are more females than males who would admit to having disordered eating behaviors, and therefore, including males in the study would lead to extremely skewed data.”

In addition to potential skew, including men would require a larger sample with increased variability than the sample obtained, because men are less likely to have eating disorders.

However, Dr. Bardone-Cone is currently developing studies that include male participants.

She also discussed the potential effect of nearly 70% of the participants being Caucasian/White. Research has been done with AfricanAmerican populations and shows similar scores to Caucasian/White people for perfectionism. She acknowledges that perhaps other groups, Dr. Anna Bardone-Cone such as Asian populations, may score higher for perfectionism, particularly maladaptive perfectionism, due to high parental expectations. For disordered eating, most women across races and ethnicities have similar rates of bulimia, while African-American women having slightly lower rates of anorexia than other groups. Contingent self-worth may be more relevant for certain groups than others, such as individuals who are from collectivist cultures.

Collectivist cultures are those that value family and work group goals above individual needs or desires.

Dr. Bardone-Cone also elaborated on the high education and socioeconomic status of the participants’ parent(s) contributing to their maladaptive perfectionism, eating attitudes, and anxiety levels. Though it is popular opinion that eating disorders are an “upper class phenomenon”, studies have disproven this. As Dr. Bardone-Cone said however, “bulimia and binge eating disorders are actually connected to low income individuals because binging allows for an escape in an

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Figure 1: Eating disorder statistics. Image courtesy of Creative Commons. easy and inexpensive way.” She also said that “socioeconomic ing perfectionism and contingent self-worth in prevention status could be more relevant in looking at perfectionism and treatment efforts for eating disorders could lower risks and parental concern over mistakes and strictness. Appear- for developing disordered eating patterns or increasing those ance-contingent self-worth may also be connected to high already in place. socioeconomic status as a marker of expectations, and relaWhile we now know that perfectionism and low selftionship-contingent self-worth may rely on the sense that ed- worth increase the likelihood of having an eating disorder, ucated parents may be concerned with their children focusing we do not have any definite predictors for anxiety, one of the on school rather than relationships. Inversely, low socioeco- goals of the study. Further research could be conducted in an nomic status could mean expectations to find a partner and attempt to find a link between anxiety and other personality settle down rather than focusing on school.” Appearance-con- traits, as well as replicating Bardone-Cone’s study with a more tingent self-worth is when self-worth diverse population in an attempt to relies entirely on perceived appearfind any difference in results. Conance, while relationship-contingent “It is popular opinion that tinuing research in Bardone-Cone’s self-worth is when one’s self worth is eating disorders are an lab includes the Road to Recovery determined by whether or not they from Eating Disorders (RRED) Study, are in a relationship. This means that ‘upper class phenomenon.’ a National Institute of Mental Health being single often also shows a de- [However] bulimia and binge (NIMH)-funded study looking to decrease in self-worth. eating disorders are actually fine recovery and understand the Bardone-Cone’s 2017 study process in more detail.2 also assessed maladaptive perfec- connected to low income The implications of Dr. Bartionism, or perfectionism not help- individuals because binging done-Cone’s research are interesting ful for the environment or situation, to consider. While it has given us valualong with appearance contingent allows for an escape in an able information, it also raises more self-worth. Appearance contingent easy and inexpensive way.” questions. The research clearly shows self-worth is how one’s appearance that certain traits, e.g. perfectionism positively or negatively affect selfand contingent self-worth, can preworth. An example of maladaptive perfectionism would be dict disordered eating. This narrows the field for research, and stressing so hard about getting a 100 on a test that the per- allows us to ask questions of what increases or buffers the risk. fectionist beats themselves up over a 98 and thinks that they Looking at these interactions gives a more nuanced picture of are worthless. The study also assessed relationship contingent who is at risk and how we can better help them to reduce their self-worth, measuring dependence of self-worth on being in negative outcomes. For researchers, this opens avenues in the a romantic relationship. The Eating Attitudes Test-26 assessed realm of eating disorder research, while for healthcare profeseating pathology. The STAI, Spielberger State-Trait Anxiety sionals, it means the potential for better treatment plans for Inventory, which measures anxious tendencies, was used to current patients and better prevention efforts. For the general assess anxiety symptoms using the trait anxiety subscale. Re- population, it means that we may soon see increased efforts searchers assessed these measures in order to determine how in schools and other public spaces to raise awareness of disorindividual’s traits may predict mental illness in the future. dered eating and work towards preventing it.

Results show that maladaptive perfectionism is positively associated with disordered eating and anxiety. In addi- References tion, both appearance and relationship contingent self-worth 1. Bardone-Cone, A. M.; Lin, S. L.; Butler, R. M.; Behav. Ther. interact to predict increases in disordered eating. This means 2017, 48, 380-390. that traits of perfectionism and contingent self-worth predict 2. Bardone-Cone, A. M.; Hunt, R. A.; Watson, H. J. Curr. Psydisordered eating. However, neither of the interactive models chiat. Rep. 2018, 20, 79. predicted changes in anxiety. Findings suggest that target- 3. Interview with Anna M. Bardone-Cone, Ph.D. 10/8/2018

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Photo courtesy of Creative Commons

Written in Rings

By Kaia Findlay

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he wooden core is thinner than a pencil and about a foot long. Across its length are alternating bands of light and dark brown wood, some wide and easily visible, others no more than a few cells thick.

The bands are the cross sections of a tree’s rings. This five millimeter core, pulled from a living, growing specimen, holds that tree’s life history, including its age and what precipitation, temperature, and climatic events it experienced each year as it grew. Amazing as that is by itself, when this core is examined in context with cores from other trees, it plots a climate record for periods of history way before any instrument or scientist existed to observe it. For 21st century scientists, this historical data gives a crucial perspective on what’s happening to the climate right now.1 “If you hear something like, it’s the warmest it’s been in the last 1,000 years, the reason we know that is because of tree rings,” said Dr. Erika Wise, a professor in the Department of Geography at UNC-Chapel Hill.2 Dr. Wise studies broad climate patterns, particularly those relating to moisture like storms, droughts and the El Niño phenomenon, by analyzing the information in tree rings.

This study of trees is known as dendrochronology.

Imagine the cross-section of a tree, the light and dark concentric circles radiating outwards from the core.

The tree puts on the light layer of growth in the early part of the year, and the darker and denser part later on, so it follows that scientists name these two kinds of growth as earlywood and latewood.

Taken together, a pair of light and dark rings represents one Dr. Erika Wise

year. In addition to marking the age of the tree, the rings hold climate information. Each year a tree doesn’t get enough sun, water, or nutrients from the soil, which are also called limiting factors, it can’t add on as much earlywood and latewood to its next ring. Scientists like Dr. Wise look for these variances in the size of the rings and extract information about what happened in the environment during the year.

But how exactly does a tree minding its own business in the forest tell a scientist how much water was flowing in a nearby stream in 1656?

First off, it has to be the right tree. Dendrochronologists prefer old trees – centuries of growth means hundreds of rings for a scientist to tap into for data. In cores from old trees, widely-spaced rings are near the center, but they get thinner and closer together near the outer edges. “Basically, if the rings are too small to see, that’s a good sign,” Dr. Wise said.2 The oldest trees in the world are found in the western United

Figure 1. Erika Wise studying a tree core at her lab in Coker Hall at UNC-Chapel Hill. Photo courtesy of Dr. Erika Wise.

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Figure 2. Wise drills a tree core with an instrument borer in Washington state. Photo courtesy of Dr. Erika Wise.

States, where Dr. Wise focuses most of her research. They are also the best trees for studying paleoclimate, because, unlike the dense forests in the East, forests in the West are sparser and more sensitive to climate.2 The perfect tree will be found in one of these sparse forests where one particular limiting factor influences the growth of the trees in that area. Since Dr. Wise studies climate patterns related to moisture, she doesn’t look for trees in lush, grassy pastures. Those trees, which have a plentiful water supply, will react to limits in other factors like sunlight and nutrients but won’t change their growth patterns as much to changes in water. Dr. Wise looks for water-stressed trees, like those on steep, rocky slopes, where any rain that falls quickly drains away. She added that trees at these sites are often protected from the saws of loggers, as their locations are too difficult for machinery to navigate.

Sometimes it takes a while to find a good site. It’s even one of the most difficult parts of the field research for Dr. Wise.

“It’s a lot of driving around and maybe getting out and hiking to this really hard-to-get-to place,” she said. “If you don’t find the old trees you’re hoping for, which is most of the time, then you hike back out.”2 Disappointment and frustration can run high in the group during the hunt, but it’s undermined by the excitement of finding a great field site.

Once she’s found an old, water-stressed tree, Dr. Wise drills into the trunk with an instrument called an increment borer to extract a core. The tree doesn’t mind. The core is about the same diameter as a straw, causing no more damage than the tree is used to from insects. After taking several cores and completing her field work, Dr. Wise heads back to the lab. There, she examines the cores and assigns an exact date to every ring by counting back from the current year and comparing between cores to account for anomalies. It’s a long process, but after many years of sampling, there are certain years—like 1632 or 1747, which were drier years in the West— that Dr. Wise can pick out instantly for reference. “It’s so neat to actually be able to see these years over and over in your cores,” Dr. Wise said. “You’re going back in time on a new core, and you’re like, yeah, there’s 1747.”2

Figure 3. Wise and Matt Dannenberg, a then-PhD candidate at UNC, study a tree core in Washington state. Photo courtesy of Dr. Erika Wise.

After the dating process, Dr. Wise sands the cores and places them into a machine called a Velmex to magnify and measure the width of the rings.2 The final step is building a model that matches the width of the tree ring to a climate variable. Dr. Wise builds the model with tree data and climate data recorded from instruments, then uses the patterns determined from that model to reconstruct climate data for times before instrument readings were available.

But trees can only tell stories from their own perspective. Dr. Wise’s current research delves into making a detailed climate record of the 1800s in the West by combining data from tree rings with diaries and historical documents from 19th century pioneers to the region. Because despite the fact that all of the dendrochronologists across the world pool their data into a source known as the International Tree-Ring Data Bank, Dr. Wise finds there are still many unanswered questions. The trees are out there, waiting to help answer them.

References

1. Wise, E. K.; Dannenberg, M. P. Sci. Adv. 2017, 3, 1-8.

2. Interview with Erika K. Wise, Ph.D. 2/7/19.

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Figure 1. Molas Pass, Colorado. Photo courtesy of Wikimedia Commons.

‘Laying’ the Groundwork for Ecological Research

By Sara Bernate

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ompetition among siblings is often an unfair battle.

With the exception of twins, the age difference between siblings causes an imbalance in their ability to compete with one another. The oldest usually bears the greatest strength, wit, and experience throughout childhood, ensuring a greater advantage over the youngest—how else would they win every wrestling match?

According to a recent research experiment conducted

by Dr. Keith W. Sockman, an associate professor of Biology at UNC-Chapel Hill, humans and Lincoln’s Sparrows are alike in their sibling rivalry and their tendency to establish a hierar-

Figure 2. A Lincoln’s Sparrow. Photo courtesy of Dr. Keith W. Sockman.

chy.1 Lincoln’s Sparrows, the focus of Dr. Sockman’s research, also vary in their competitive ability. For these bird siblings, however, a championship title is not all that is at stake. Their competition is essential for survival.

Lincoln’s Sparrow, a type of songbird, lay one egg per day. The average nest contains four eggs. Once the female lays the first egg, she begins to incubate, or provide adequate conditions for development and growth by sitting on the egg.

The female Sparrow continues to incubate the growing nest as she lays the remaining eggs.2 When ready, the eggs hatch sequentially rather than simultaneously, referred to as hatching asynchrony. This sequential hatching usually follows their laying order, or their oviposition.3 For years, although untested, scientists have long assumed the following hypothesis: hatching asynchrony is caused by the direct relationship between an egg’s oviposition and incubation exposure.3 The first laid egg is exposed to incubation before its siblings, which gives it a head start in development. A delayed onset of exposure to incubation causes a greater delay in the development of each subsequent egg, evident after hatching. The egg that hatches last, or the youngest bird, is usually the smallest and the weakest.

These qualities are disadvantages in the competition for parental care and the overall chances of survival.1 This assumed hypothesis and its subsequent effects has been referred to as the oviposition hypothesis.1

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Figure 3. Both photographs feature the same siblings. The top was photographed on the day of hatching and the bottom was photographed 7-days post hatching. The strong variation in growth among siblings is evident in just their size.

Photo courtesy of Dr. Keith W. Sockman.

Dr. Sockman’s five-year experiment is the hypothesis’ first demonstration. His interest in this topic stems from his time as a PhD student, in which he says to have devoted to “understanding, in part, the physiological mechanisms that drove the onset of incubation behavior.1” To demonstrate the hypothesis, the research study compared the first laid eggs of two groups: the experimental and the control nests. Within the experimental group, Dr. Sockman switched the first laid egg of one nest with the fourth laid egg of another nest. Dr. Sockman only performed this switch with eggs laid on the same day. This switch resulted in a first laid egg positioned fourth in a foreign nest, causing the egg’s delayed onset to incubation.3 In the control group, Dr. Sockman switched the first laid egg of one nest with the first laid egg of another nest. Because the eggs remained in their same position, but in foreign nests, both experienced simultaneous onset to incubation.

This switch controlled for factors other than oviposition and hatching asynchrony, such as the genetic makeup of the egg, that otherwise could have affected the experimental results.1 Once the eggs hatched, Dr. Sockman and his team of undergraduate students and lab technicians collected a variety of measurements, such as body mass, body size, and bill width gape.1 In the results of each experimental nest, the eggs that were laid first in their original nest but placed last in foster nests hatched last. In the control group, the majority of the switched eggs, laid first and positioned first, hatched first.3 Although these results were of no surprise to Dr. Sockman, they were important because “this was the first demonstration, experimentally, that what everybody assumed is correct is correct.”1 That is, that the order in which the eggs are laid and exposed to incubation determines the order in which they hatch.3 Most exciting to Dr. Sockman were the implications derived from the experimental results. The first laid eggs, posi-

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Figure 4. Two Lincoln’s Sparrow hatchlings. Photo courtesy of Dr. Keith W. Sockman. tioned last, hatched the smallest birds among the nests. The differences in their physical nature limit their access to food and parental care, and thus their future survival.1 The results expanded to account for the effects of oviposition and hatching asynchrony on a Lincoln’s Sparrows’ quality of life. For instance, the first laid but last hatched birds developed a wider bill, or beak, than its siblings. Songbirds depend on their bill for the production of sexual songs to attract mates and reproduce. The birds’ resulting wider bill negatively affects their song performance, thus decreasing their reproductive success.3 Beyond adding to the scientific discoveries within developmental biology research, Dr. Sockman’s experiment aids in the understanding of the ways in which the environment induces gene expression and forms incredibly varied individuals. He is looking forward to future projects, hoping to further investigate the effects of hatching asynchrony on the growth and development of young Lincoln’s Sparrows. Specifically, he wants “to explore the relationship between bill morphology and male song production, among other projects.1 In essence, his future research will focus on a larger Dr. Keith W. Sockman battle: one fought among adult and his daughter male birds in their search for a mate.

References

1. Interview with Keith W. Sockman, Ph.D. 2/01/19.

2. Ehrlich, P. R.; Dobkin, D. S.; & Wheye, D. Hatching Asynchrony and Brood Reduction. In The Birder’s Handbook: A Field Guide to the Natural History of North American Birds: Including All Species That Regularly Breed North of Mexico, Simon & Schuster: New York, 1988; pp 307-309.

3. Sockman, K. W. Biol. Lett. 2018, 14, 20180658.

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Our Oceanic Secret Saviors

By Sophie Troyer

Illustration by Taylor Thomas

T

he last frontier, the depths of the ocean: a place on Earth very few people have been. The life there is largely undiscovered. It is like nothing else. Large mats of microbes, colored by sulfur, cover the seafloor and feed on the elements released by hydrothermal fluids. Riftia, the genus of giant tube worms, cover surfaces of hydrothermal formations, forming what looks like an underwater garden. This dark underwater landscape, Guaymas Basin, at a depth of 2000 meters in the Gulf of California, Mexico, contains hydrothermal vents that spew hydrocarbons.

Guaymas Basin is a young and active rift basin, where new seafloor is created as the underlying ocean crust spreads apart. Thick sediment layers cover the hot spreading center and are interlaced with freshly emplaced layers of basaltic lava, also called volcanic sills. Around the sills, heat from the magma transforms organic material embedded in the sediment into gases, including CO2, methane, low-molecular weight organic acids, ammonia, and various hydrocarbons.

The transformation of sedimented biomass, mostly derived from plankton that settles on the seafloor, into petroleum hydrocarbons makes Guaymas Basin unique. These deeply sourced fluids that migrate up towards the seafloor bring petroleum hydrocarbons to the microbial communities that break them down and use them.1 By transforming fossil carbon compounds into microbial biomass, they are reinjected into the food web of the hydrothermal ecosystem, and returned to the biosphere.2 The minerals dissolved in hydrothermal fluids, especially sulfides, carbonates, and siliDr. Andreas Teske

cates, solidify when the hot fluids encounter the cold deepsea water. The result is the formation of massive hydrothermal mounds, tall hydrothermal edifices 10 to 20 meters high, and delicate chimney- or flute-like structures that are surrounded by microbial mats and Riftia.1 Research on Guaymas Basin combines the fields of geology, chemistry, and biology. Therefore, it is important to understand each of these individual aspects to understand the big picture of hydrothermal vents and their impact on the surrounding environment. Dr. Andreas Teske from the Department of Marine Sciences at UNC-Chapel Hill stresses the importance of understanding the ocean as an interconnected system: biological, physical, geochemical, and other factors all work together. His research focuses on marine microbiology and biogeochemistry. He uses molecular techniques, such as genomic analysis, to study microbial diversity and how it interacts with the biogeochemistry of the environment. He sees the general importance of his research as extending the diversity of microbial life and understanding the range of processes

Figure 1. Guaymas Basin microbial mats. Photo courtesy of Woods Hole Oceanographic Institute.

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Dr. Teske became interested in this research by seeing the Guaymas Basin during deep-sea submersible dives as a postdoctoral researcher in 1998. It was fascinating for him to see the bizarre geological formations, microbial mats, deep sea life, and how they are all interconnected. It is a deeply complex biological system with geological roots—therefore its research requires a multidisciplinary perspective. Evolutionarily, this research involves discovering new branches of the tree of life and new processes encoded in microbial genomes that no one knew microorganisms could perform. The full natural diversity in microorganisms is unknown, and there are life forms in this relatively unexplored environment that remain to be discovered. Dr. Teske explains that working in the field and visiting the field site are some of the most enjoyable parts of his research. Very few people have seen this with their own eyes, so it feels similar to exploring outer space.2 However, working in the field is only a small part of the research process. Research cruises require only a few weeks to collect samples on an expedition, but take many years to fund and to organize. During the interim at the home lab, the research team analyzes these samples and crunches data.

Geochemical measurements, microbial studies, and genomic analyses require months or years of research in the home lab.

In addition to the obstacle of organizing cruises and acquiring funding, working in the Basin requires Mexican collaboration—good relationships with Mexican scientists and their home institutions are essential to the research. Notably, Guaymas Basin is a Mexican underwater biosphere preserve, and destructive sampling has to be avoided.2 According to Dr. Teske, the significance of his work is the potential for working with microbes that cycle organic carbon and fossil carbon. Genomic investigations are carried out to identify the makeup of the microbial communities. Since these microbes can recycle fossil carbon into biomass and reinject it into the biosphere, investigating them allows for the exploration of the natural pathways that are available in nature for changing carbon fluxes. Current applications of this research include isolating microorganisms that break down hydrocarbon compounds under anaerobic conditions and high temperatures. This knowledge can help with the understanding of processes that could impact climate change. Investigating these microorganisms could lead to applied solutions for hydrocarbons. Only microorganisms are consuming the Deep Horizon oil spill; perhaps this could be used to the advantage of cleanup efforts. More generally, understanding what exists in Guaymas Basin in terms of microbial life forms and capabilities makes it possible to understand how the interactions of extreme microbial life with biochemical properties shape the biosphere. These are the “microbial architects of planet Earth.”2 An understanding of the geological and chemical setting is necessary to understand how the biology in the area of a hydrothermal vent works. According to Dr. Teske, “In marine science, interdisciplinary work is practically a way of life. If you try to stay strictly within the boundaries of one discipline you won’t get very far. You need to understand some knowledge of subjects nearby.” These interdisciplinary perspectives, like

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the ones of Dr. Teske’s research, are essential to understanding the world around us.2

References

1. Teske, A., et al. Front Microbiol. 2016, 7, 1-23.

2. Interview with Andreas Teske, Ph.D. 2/12/19.

Figure 2. (Top and middle) Guaymas Basin hydrothermal edifices and chimneys. (Bottom) Guaymas Basin Riftia, during Alvin submersible dive 5000. Photos courtesy of Woods Hole Oceanographic Institute.

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Figure 1: Burning fossil fuels results in both climate-warming greenhouse gases and the pollutants most dangerous for human health.

Image courtesy of Ralf Vetterle.

Air Pollution and Climate Change: A Dangerous Mix

By Sara Edwards

W

e might not think a lot about the air we breathe, but when air quality is poor, our bodies notice. And climate change will probably make it worse.

Dr. Jason West’s research focuses on the interactions between climate change and air pollution. As a climate scientist, he knows how important it is to bring solid facts to the table when talking about his work. Dr. West chooses his words deliberately and precisely: “As climate changes, it changes air pollution. It wouldn’t be the case necessarily that every place in the world would be worse as a result of climate change. But many places would be.”1 The good news is the solution to both climate change and air pollution is the same: reducing greenhouse gas emissions.

“Many of the things that we would do to address air pollution do not necessarily have a big effect on climate change,” West says. “But most of the things that we would do to address climate change would have a big effect on also reducing air pollution.” Mainly, decreasing the consumption of fossil fuels.

By reducing emissions through improving public transportation or switching to renewable energy sources, we can mitigate climate change and improve air quality.

In 2013, West and his team did something unprecedented—they used a global model of the atmosphere to

Dr. Jason West simulate how pollution might move around the world under future climate scenarios.2 They wanted to see how reducing greenhouse gases (GHGs) might affect the amount of pollution in the atmosphere and, consequently, reduce the number of deaths or illnesses—the “co-benefits” of GHG reduction. No other co-benefit studies had looked at a global scale before, and most never took the effects of climate change into account because they only focused on regional or local impacts.

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Figure 2: Change in fine particulate matter (left) and ozone (right) concentrations in 2050 because of global GHG reductions.

The spatially smoother picture for ozone reflects that most ozone reductions in the US come from foreign and methane emission reductions, whereas most fine particulate matter reductions come from domestic GHG reductions. Image courtesy of Dr. Jason West.

West’s model contained two future policy scenarios: a “business as usual” scenario and another that simulated a global carbon tax. By comparing the two scenarios, the researchers could see how effective global action to reduce emissions could be in preventing deaths related to air pollution. It took an interdisciplinary effort to build and analyze the scenarios, West said: “We needed to know something about energy and economics, about greenhouse gases and mitigation options, and about atmospheric science and epidemiology for what it means for health effects.”1 Using this model, West showed that by the year 2100, the global carbon tax scenario reduced premature deaths by up to three million—a value of $50 to $380 per metric ton of carbon dioxide removed.2 For the next step in the study in 2016, West’s Ph.D. student Yuqiang Zhang zoomed in for a closer look at the United States.3 What the researchers found was not entirely what they had expected.

To understand the significance of West’s research, it helps to understand how air quality affects human health—and how climate change might threaten both.

There are two main air pollutants that impact human health: ozone and fine particulate matter. Ozone, a component of smog, is formed when sunlight reacts with emissions from our vehicles and smokestacks. When we breathe ozone, it causes inflammation of our lungs and worsens conditions like asthma and heart disease.4 On the other hand, particulate matter is made up of microscopic, airborne particles like soot

that can get deep inside our lungs and cause cancer.4 Both ozone and particulate matter are produced through burning fossil fuels—the main culprit behind climate change. West says climate change will make air pollution worse in many places in the United States because of increased temperatures.1 Higher temperatures in the atmosphere make chemical reactions move faster, which produces higher concentrations of ozone and particulate matter.

In their 2016 study, West and Zhang used the same groundbreaking global model and emission reduction scenarios to see how GHGs affected air quality in the U.S. But they took it a step further by teasing out the effects of domestic versus global reduction efforts. What surprised them was that, while reducing domestic particulate matter concentrations had the biggest health impact in the U.S., the health impact due to ozone was mostly influenced by emissions blowing over from other countries. In other words, air quality in the U.S. partly depends on what the rest of the world is pumping into the atmosphere.

“And so, we do have this sort of global commons thing, a global background of air pollution that affects everybody,” said West. “Especially when we look over long term scenarios, what’s happening in other countries becomes even more relevant for the United States as time goes by.”

The implications of this research are important when it comes to combatting climate change and its impacts on our

What surprised them was that, while reducing domestic particulate matter concentrations had the biggest health impact in the U.S., the health impact due to ozone was mostly influenced by emissions blowing over from other countries.

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ecology health. While previous studies often ignored the global movements of pollutants, West and his team revealed that they do not stay confined within the borders of any one nation. The future of air quality in the U.S. depends on whether global efforts to reduce greenhouse gas emissions succeed.

For Dr. Jason West, the question is, what’s next? As a nation, “we’ve sort of addressed air pollution without taking big strides to address climate change at the same time,” he said.

“Going forward now, do we continue to ratchet down air pollution, which is a good thing for health, but leave greenhouse gas emissions alone? Or do we think about other strategies that would address both problems at the same time?”

Movement to a low- or even a zero-carbon future, he believes, would go a long way towards reducing air pollution in this country and around the world—a win-win situation for the climate and human health.

References

1. Interview with J. Jason West, PhD. 2/07/19.

2. West, J. J.; Smith, S. J.; Silva, R. A.; Naik, V.; Zhang, Y.; Adelman, Z.; Fry, M. M.; Anenberg, S.; Horowitz, L. W.; Lamarque, J. F. Nat. Clim. Change 2013, 3(10), 885-889.

3. Zhang, Y.; Bowden, J. H.; Adelman, Z.; Naik, V.; Horowitz, L. W.; Smith, S. J.; West, J. J. Atmospheric Chem. Phys. 2016, 16, 9533-9548.

4. American Lung Association. Health Effects of Ozone and Particle Pollution. https://www.lung.org/our-initiatives/ healthy-air/sota/health-risks/ (accessed February 18, 2019).

Figure 3: Co-benefits of global GHG reductions for avoided air pollution mortality in 2030, using a high value of a life (red) and low value (blue) compared to the cost of GHG controls (green). Image courtesy of Dr. Jason West.

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How PELICANS Can Teach Students to be Data Scientists

By Megan Butler

Figure 2. Photo of pelicans used in the pelican problem to simulate a sample from one pelican colony. Photo courtesy of Daniel Petrescu.

M

ath is hard—but is statistics math? The short answer is not really, no. While it’s a hot topic for debate within the STEM community, many view statistics as a science that simply uses math to compile evidence that leads to some conclusion. However, the subject has long fallen prey to the traditional nature of math education: a teacher stands at the front of the classroom and talks at the students, forcing the students to learn strictly through mimicking. Though this lecture method can still be valuable, recent pedagogical research has been largely in favor of a more interactive classroom in which the students have an active role particularly through statistical modeling—the process of using mathematical approaches to make sense of real-world phenomena.1 Introductory statistics courses have typically been treated as solely a “math” class; the students use their calculators to produce numbers that have some meaning and then move on.

Dr. Jeffrey McLean was hired in the Fall of 2018 to take part in the redesign of UNC-Chapel Hill’s introductory statistics courses in an effort to align teaching with how students best learn statistics. As it turns out, it may be most effective to put students in the role of a data scientist, a position that includes sorting through and making meaning of data in a real-world situation.2 Dr. McLean originally pursued his Ph.D. in math. As a TA, he volunteered to teach a statistics course because no one else wanted to do it—they were all math people, after all.

And he struggled with the experience. Since he saw statistics as strictly a “math” class, he didn’t like the way he knew how

to teach the course. The next thing he knew, he was writing a dissertation not about algebra or topology, but about how to improve introductory statistics education by providing students with hands-on learning experiences.2 In his early research, Dr. McLean focused on teaching statistics through simulation, specifically with a method of resampling—drawing many samples from an original sample —called bootstrapping (Figure 1). Resampling has typically been taught with a more mathematically complex approach.

However, thanks to improvements in technology, the much simpler process of bootstrapping can be simulated almost instantaneously, making this new educational approach easily accessible and a growing trend.3 The purpose of bootstrapping is to be able to make claims about a population based on just a sample. Bootstrapping starts by looking at one sample from an unavailable population, one you can’t see. Imagine you have 10 apples as your singular sample: 4 green and 6 red. To bootstrap, you take one apple, record its color, and then put it back (this is called sampling with reDr. Jeffrey McLean

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Figure 1. Visualization of a method of resampling called bootstrapping. Image courtesy of Dr. Jeffrey McLean. placement) and repeat this until you record as many apples as your original sample. The 10 apples you recorded is called the bootstrap sample, and it can be composed of any combination of green and red apples due to sampling with replacement.

Many bootstrap samples can be taken and each can produce a statistic—like a proportion of red apples—and those multiple proportions create a bootstrap distribution.3 The range of the distribution is likely to contain the actual proportion of red apples in the whole population. So, even though you only saw one sample, you could still predict something about the whole population, and that is the power of bootstrapping!

While this idea might sound complicated at first, it is vital for making statistics more realistic because an entire population is often not available to look at.

Since teaching statistics through simulation and modeling is such a young field, Dr. McLean wanted to investigate how people can learn about the resampling process.

Rather than simply lecturing about bootstrapping, he first had students attempt to explore on their own what to do with one sample and no population. Through various modeling activities, Dr. McLean found that students were able to apply what they already knew about taking samples and making inferences with an available population to construct a process similar to bootstrapping.3 In the activities, students developed their own reasoning to make sense of the data they were given—they learned by trial and error as opposed to having a teacher explicitly tell them how to correctly solve a new problem.

Currently, Dr. McLean and his collaborators are looking at how various groups of individuals perform a certain modeling activity to understand how different people can develop statistical reasoning. The activity is all about everyone’s favorite large water bird, the pelican. Participants are given two pictures that represent samples from pelican breeding grounds (Figure 2). They are also given the maps of the breed-

ing grounds (Figure 3). The goal is to estimate how many pelican nests are in each of the colonies.2 The data in the pelican activity is simply an image, which models how vague data usually is in reality. The question is what data you need, and in the case of the pelicans, how you can get that data from the image. As Dr. McLean says, “A lot of times in statistics classes you have very perfect data that fits your exact situation and you can use it to get an answer. [But] that’s not how it ever is in the real world.”2 Originally, the pelican problem was a middle school activity about proportions and area. But Dr. McLean and his fellow researchers instead saw it as an opportunity to look at how individuals would go about solving something with limited information and what assumptions they would make. So far, the researchers have looked at 4th and 6th graders, high schoolers, engineering students in Mexico, preservice teachers, math coaches, and statisticians. It is clear that the way those groups approach the problem will diverge, but being able to make sense of how different people tackle this activity will enable researchers to begin to answer the question Dr. McLean posed: “When I put people in the role of a data scientist, what type of learning happens?”2 Going forward,

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Illustration by Taylor Thomas

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Figure 3. Colony maps for the pelican activity that students are challenged to find the area of. Image courtesy of Aran Glancy. that question will guide much of his work.

Dr. McLean is in the process of redesigning the introductory statistics courses at UNC to develop a data science/ inference course about actually using statistics, not just performing computations of statistics. Activities like the pelican problem are going to be integral to this curriculum development; Dr. McLean hopes to focus the class around such modeling and problem solving because it asks students to engage in the same kind of data analysis that happens in the real world.

His research is particularly exciting for him because he can see its direct impacts through his own teaching. However, he sees implementation as a significant obstacle because a class like the one he is creating is such a departure from the norm.

While many people view research as primarily being in the hard sciences, STEM education research broadens the field as a whole, giving more people a chance to engage in STEM by teaching it the way all students will have the best opportunity to learn.2 Remember when you’re sitting in class —a lot of thought goes into what happens during those 50-75 minutes, even when your lesson seems to be just about pelicans.

References

1. Garfield, J.; delMas, R.; Zieffler, A. ZDM Mathematics Education 2012, 44, 883-898 2. Interview with Jeffrey A. McLean, Ph.D. 2/5/19.

3. McLean, J. A; Doerr, H. M. A Bootstrapping Approach to Eliciting Student’s Informal Inferential Reasoning through Model Development Sequences. In Mathematical Modeling and Modeling Mathematics; Hirsch, C. R., McDuffie, A. R., Eds.; Annual Perspectives in Mathematics Education; National Council of Teachers of Mathematics: Reston, VA, 2016; pp 163-173.

Training the next generation of medical leaders

of times in statis“ Aticslotclasses you have very perfect data that fits your exact situation and you can use it to get an answer. [But] that’s not how it ever is in the real world.

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Whole-person approach to patient care

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technology and innovation Figure 1. Network interactions in patients with Parkinson’s disease, as recorded using restingstate functional MRI. Image courtesy of Dr. Eran Dayan.

Running Shoes and Parkinson’s Disease

By Divya Narayanan Dopamine: a tiny, easily overlooked molecule. However, this twenty-two-atom compound plays a huge role in human activity as a messenger between neurons, or nerve cells, in the brain. From movement to emotion to addiction, dopamine is involved in many of our daily behaviors.1 A particular region of the brain, the substantia nigra, produces the dopamine that assists in beginning movement and speech.1 As the cells in the region die, people often have trouble initiating movement, which can give rise to some of the characteristic symptoms of Parkinson’s Disease.

Parkinson’s Disease (PD) is a nervous system disorder that includes symptoms such as tremors, slow movement, and balance problems. While PD itself is not fatal, its complications can be. Additionally, the cause of the disease remains unknown. “Parkinson’s Disease may also give rise to non-motor symptoms, such as cognitive dysfunction, including memory issues, and problems in decision making,” said Dr. Eran Dayan, an assistant professor in the UNC-Chapel Hill School of Medicine’s Department of Radiology.2 “What we attempted to find out is whether physical activity can possibly mediate some of this cognitive decline.”

One of the most challenging aspects of treating Parkinson’s Disease is the declining effectiveness of drugs on advanced-stage patients.

Current common pharmaceutical treatments are designed to enter the brain and be converted into replacement dopamine. Although patients may see an initial significant improvement with the dopamine-replacement drugs, the effects may ultimately diminish or become inconsistent.1 Dr. Eran Dayan This presents clinicians

and patients with a lack of effective treatments. Researchers like Dr. Dayan search for hidden pieces in the Parkinson’s puzzle in order to better understand the disease and hopefully create better treatments.

Dr. Dayan, along with Dr. Nina Browner and Dr. Miriam Sklerov of UNC Neurology and postdoctoral fellow, Dr. Chia-Hao Shih, aimed to find out “the extent to which the association between dopamine transporter availability in the striatum, a collection of regions in the brain, and cognition in PD is affected by physical activity.”2 The team of researchers set out to analyze data from nearly two hundred patients with Parkinson’s in order to determine the links between the three factors: dopamine transporter ratio, cognition, and physical activity. Dopamine binding ratios were found for each patient from a brain imaging scan of the caudate and putamen, regions of the brain that facilitate voluntary movement. A decrease in dopamine transporter availability is an emerging marker for Parkinson’s Disease due to the transporter’s essential function in moving dopamine from space surrounding the cell to within the cell. Researchers also observed the cognition of patients with a test that assesses attention, memory, visuospatial ability, and general executive function.3 Just as the team of researchers hypothesized, there was a clear statistical mediation effect by physical activity in the association between SBR and global cognition rating.

Higher scores in each category were associated, while lower scores also occurred concurrently. “Maybe not a direct, causal effect, but certainly an indirect, statistically significant association between the variables, that is what we found,” said Dr. Dayan in regards to his findings.2 The results suggest that physical activity may have neuroprotective effects in countering cognitive decline. A neuroprotective event is one that can slow down or even salvage or regenerate cells in the nervous system. A similar process might be at work in neurodegenerative diseases in general—although the functional mechanisms by which it occurs are not currently well understood. But the question

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Figure 2. Network interactions in patients with Parkinson’s disease, as recorded using resting-state functional MRI. Image courtesy of Dr. Eran Dayan. remains: what about physical activity leads to the favorable association between cognition and dopamine availability? Dr. Dayan proposes the answer of neuroplasticity, consistent with the apparent neuroprotective qualities of exercise in relation to dopamine. “We think it has to do with neuroplasticity, essentially how the brain can adapt and reorganize. It could be that being physically active is inducing this new creation of dopamine.”2 The association articulated in Dr. Dayan’s study could have far-reaching consequences in terms of current medical treatment for symptoms of Parkinson’s Disease. Since physical activity mediates striatal dopamine transporter ratio and cognitive scores, physical activity as a treatment is not unreasonable. PD patients are largely less active than other individuals of the same age.4 Therefore, more research and emphasis should be invested towards creating methods of improving and increasing physical activity in PD patients in order to treat their cognitive and motor symptoms.

References

1. Brookshire, B. Explainer: What Is Dopamine? Science News for Students. www.sciencenewsforstudents.org/article/explainer-what-dopamine (accessed February 1, 2019) 2. Interview with Eran Dayan, Ph.D. 2/1/19.

3. “Parkinson’s Disease.” Mayo Clinic, Mayo Foundation for Medical Education and Research, www.mayoclinic.org/diseases-conditions/parkinsons-disease/diagnosis-treatment/ drc-20376062 (accessed February 1, 2019) 4.Shih, C.; Moore, K.; Browner, N.; Sklerov, M.; Dayan, E. Parkinsonism Relat. Disord. 2018.

Figure 3. Classification of prodromal Parkinson’s disease using multimodal MRI and a machine learning approach. Image courtesy of Dr. Eran Dayan.

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technology and innovation

Paint Your Lung with Hyperpolarized Gas

By Zelong Yin

Image courtesy of Creative Commons

D

o you know what the scene is like when a patient needs a lung check? Usually the doctor will put a tube (which is connected to a device called a spirometer) in their mouth, and they will be asked to blow into the tube’s small hole. This sounds a little old-fashioned, but this process, called a Pulmonary Function Test (PFT), is exactly what one might encounter when being tested for lung disease. You may be wondering: how can physicians rely on a single tube for such a critical diagnosis? Indeed, a primary problem with PFTs is their inability to detect early changes taking place at the level of small airways.1 Fortunately, scientists can now peer into these “void zones” of lungs with the help of a new appealing technique called the Hyperpolarized Gas Magnetic Resonance Imaging (HP Gas MRI).

Dr. Tamara Branca at UNC-Chapel Hill is currently working with the Marsico Lung Institute to use this technique to image the lungs. This technique takes advantages of a method called Spin-Exchange Optical Pumping to increase the MR signal by 5 orders of magnitude, thus making things, such as gases, that are normally invisible in MR images, visible. The inhaled gas can then provide a detailed 3D image of the airspaces in the lungs—revealing the location of the ventilation, or air supply, defects which are common in patients with pulmonary diseases. The team (see Figure 1) is currently quantifying lung ventilation function on a regional level in subjects with cystic fibrosis (CF), in which disease progression or response to therapies can only be assessed at the global level using traditional approaches like PFTs. If one were to take a MRI scan, they would be asked to lie down flat on a panel as they are transported inside the

chamber of a big machine, all while remaining completely still. Do you ever wonder how the buzzing machine works?

The images are typically of water, or more specifically, images of the nuclear spins of 1H (hydrogen) atoms. The nuclear spins are like little bar magnets that can be aligned or “polarized” when placed under a magnetic field—that is, some invisible lines shoot out from the pole of a magnet. The MRI scanner produces an extremely strong magnetic field (usually 1.5-3 Tesla)—strong enough to lift a car—that polarizes the nuclear spins in the body. However, instead of being exactly aligned at the polarized direction, they tend to revolve around this direction, a process called precession (see Figure 2). To spatially encode the spins and generate images, the machine produces magnetic field gradients which change the magnetic fields at different locations such that nuclear spins at different locations oscillate at varying frequencies.

The collective signal produced by spins precessing at different frequencies is then analyzed using a mathematical tool called Fourier Transformation, which provides intensity information at difDr. Tamara Branca ferent frequencies

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Figure 1. A photograph of Professor Branca (second from left) with her team members in laboratory. The huge white device with a lying panel is the MRI scanner. Photo courtesy of Dr. Tamara Branca.

Figure 3. Hyperpolarized Gas MRI scanning. MRI produced using the signal from HP Gas (left). Conventional MRI of the same subject (right). Small branches of lungs clearly visible in HP Gas MRI scan. Photo courtesy of Dr. Tamara Branca.

that correspond to different parts of the body. Therefore, a plot of intensity reflects the structure of the body—the denser the tissue, the brighter it appears on the plot.

So, why bother to use Hyperpolarized Gas Magnetic Resonance Imaging (HP Gas MRI) when hospitals have MRI scanners? The answer is that although typical MRIs reflect body structures fairly well, they are sensitive to the types and amounts of matters in your body. “When you do a MRI, what you detect is basically water,” explained Dr. Branca, “and that is because there are lots of hydrogen atoms in your body in the form of water, whose nuclear spin is detectable by MRI.” 2 Other atoms that are MR-visible, like carbon-13, are less abundant and, as a result, their signal is much weaker. In addition, due to thermal equilibrium, a great portion of atoms do not polarize well under the magnet, making the signal even weaker. “The difference in energy between spins that are aligned or antialigned by the main magnetic field is comparable to thermal energy, practically making these two (low and high) energy levels equally populated,” said Dr. Branca, “as a result, the signal you would get from a million spins (influenced by thermal energy) is equivalent to the signal that you would get from just one polarized spin.” To account for this inefficiency, Dr. Branca and her team use a technique called nuclear spin hyperpolarization (NSH), which forces the nuclear spins to stay on one of the energy levels, thus increasing spin polarization.

Usually NSH can be achieved by placing the spins in an extremely large magnetic field and very low temperatures, but this approach is clearly unfeasible for humans. So, the solution is gas hyperpolarization via SEOP, a technique which polarizes

the gas without the need for high magnetic fields or low temperatures. This technique produces hyperpolarized gases that polarize into the same energy level extremely well, reaching nearly a 100% proportion. For example, you can easily polarize noble gases such as 3He and 129Xe, which are chemically stable and fit well into human body. Once polarized, the gas is inhaled into the lungs and emits extremely strong signals under the MRI scanning to create clear pictures of the cavity.

As shown in Figure 3, the details of the lungs are made clearly visible by contrast of the signal from the HP gas that fulfills every corner of the lungs.

The utilization of Hyperpolarized Gas in MRIs, especially 129Xe, has a lot of promise for making qualitative diagnoses and assessments of respiratory diseases, including asthma, chronic obstructive pulmonary disease, and pulmonary fibrosis. “It can provide spatial information on lung function that cannot be obtained by any other means” says Dr. Branca. It also serves as a biomarker that monitors relative drug efficacy and stratifies treatment.3 Currently, Dr. Branca is working with the UNC Cystic Fibrosis Center & the Marsico Lung Institute on the functions of Hyperpolarized Gas MRIs in clinical applications. This technique has been proved useful for diagnosing cystic fibrosis, according to Dr. Branca, since it is done “without exposing the patient to radiation, a particularly important point for patients with CF, who are generally young.” Hopefully, in the future, this technique will be put into commercial use and become a key diagnostic tool for lung diseases like cystic fibrosis.

References

Figure 2. Illustration of the precession of magnetic dipoles inside the varying (gradient) magnetic field. Photo courtesy of Wikimedia Commons.

1. Roos, J. E.; McAdams, H. P.; Kaushik, S. S.; & Driehuys, B. Hyperpolarized Gas MR Imaging: Technique and Applications. In Magnetic resonance imaging clinics of North America, 2015; Vol. 23, pp 217-29.

2. Interview with Rosa T. Branca, Ph.D. 1/28/19 3. Barskiy, D. A.; Coffey, A. M.; Nikolaou, P.; Mikhaylov, D. M.; Goodson, B. M.; Branca, R. T.; Lu, G. J.; Shapiro, M. G.; Telkki, V. V.; Zhivonitko, V. V., et al. NMR Hyperpolarization Techniques of Gases. In Chemistry (Weinheim an der Bergstrasse, Germany), 2016; Vol. 23, pp 725-751.

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technology and innovation

Individualized Injury Prevention

By Janie Oberhauser Figure 1. Computer-generated 3D image of low-density bone structure. Photo courtesy of Shuttershock.

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he scene is as familiar as it is devastating; a fallen figure lies splayed out on the court, or the field, or the ice as the crowd falls silent and the sporting event in question comes to a screeching halt. A flock of trainers and coaches surround the player, and the onlookers collectively hold their breath. Unfortunately, while stretchers and emergency medical visits often accompany such incidents, good news rarely follows. Season and even career-ending injuries represent the worst nightmare of any athlete or sports fan. However, a team of researchers in the Exercise and Sports Science Department’s neuromuscular research lab are working to reduce the prevalence and severity of sports-related injuries through the implementation of PRIME testing, or a physical readiness and integrated movement efficiency evaluation.1 Dr. Darin Padua, the project’s primary investigator, emphasizes that the research his lab performs surrounding this evaluation focuses on understanding, “what puts a person at risk for suffering an injury while participating in exercise or sports.” From there, he and his team work to develop strategies with which those risks can be mitigated.1 This preventative approach requires the establishment of a baseline physical profile for each individual athlete, and this is where PRIME comes in. Dr. Padua and his lab first implemented the testing among UNC’s varsity athletes in an effort to see if the they could boost individual and team performance by means of injury prevention, a process which has proven beneficial so far. Athletes participate in the screening during their preseason, a process which requires them to progress through several types of tests.

The first stage of PRIME testing comes in the form of a

biomechanics evaluation, where athletes are recorded preforming a series of basic functional tasks.

For example, a computerized plate built into the floor of the lab allows researchers to track the magnitude and distribution of the force an athlete applies to it while performing a routine exercise, such as a squat. Not far from the plate sits a network of cameras and dot-sized sensors reminiscent of the set-up Hollywood directors use for motion capture before the raw footage is Dr. Darin Padua transformed via CGI. This equipment serves a similar purpose, allowing the precise angles and patterns of an athlete’s movements to be tracked, rendered, and quantified. The second stage of testing involves a series of mobility and range of motion testing that targets the various joints of the body. The team dials in on anything from the underlying trends in an athlete’s functional movements to a lack of flexibility in a certain area; any of these signals conjure figurative red flags when it comes to predicting injury risk.1 The final component of the testing assesses the athlete’s bone mineral density, muscle mass, and overall body composition using a DEXA scanner: an instrument that consists of a cushioned table set below an X-ray beam. The scanner emits low doses of radiation in order to create a visual and statistical readout of the athlete’s physical structure and

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Figure 2. The DEXA Scanner. Photo courtesy of Wikimedia Commons.

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Figure 3. A subject performing a jump landing on the force plate. Photo courtesy of Dr. Darin Padua.

how it has responded to years of training.1,2 Again, Dr. Padua’s screening not only in the upper echelons of collegiate and proteam catalogues weak spots and generates a general biologi- fessional athletics, but also for those who exercise on a more cal profile for the athlete in order to predict where the athlete recreational level. According to WHO, the dangers of sedenruns the greatest risk of injury. With this data, they generate tary living represent a growing threat to the global populaa list of ways in which the individual can minimize that risk tion, with approximately 2 million related deaths each year.3 by improving their basal ratings in areas such as flexibility, or And as Dr. Padua points out, “Injury is very often the greatest body composition. This report is then passed on to coaches, barrier to staying physically active.”1 He and his team hope to trainers, and sports medicine staff members in the hopes that break this barrier with the information and recommendations any recommendations can be integrated into the athlete’s provided by PRIME testing. After all, whether an individual is a training program.1 varsity athlete or a more casual sports enthusiast, avoiding in“It’s very much a team approach,” Dr. Padua emphasizes. jury motivates improved performance and the full enjoyment He points out that what makes the PRIME system work so well of all the benefits that accompany remaining physically active. here at UNC is the “partnership” beWith this in mind, the Padua tween the Exercise and Sports Sci- “Just as the body type of a foot- lab’s campaign for injury prevenence department, which includes tion has already begun to make student researchers, and the uni- ball player varies from that of a significant strides off campus. The versity’s athletic departments.1 In tennis player, a profile detailing Department of Exercise and Sports fact, a large number of UNC’s varScience has also hosted several sity athletics programs already par- the most prevalent injury risks scaled-down screening opportuticipate in PRIME testing, including for a gymnast will not necessar- nities for youth sports programs, the football program, cross counsuch as the Triangle United Soctry, men’s and women’s basketball, ily provide an accurate picture of cer Association and North Carolina soccer, and lacrosse.1 the physical maladies that might Football Club, in the Raleigh-DurHowever, because PRIME ham area. These events instruct testing and the implementation sideline a softball player, or a young athletes in proper warmup of the prediagnostic information it techniques and other methods of swimmer, midseason.” provides requires such widespread injury prevention in order to keep buy-in and represents something new for both athletes and young athletes on the field and embracing a healthy lifestyle.1 coaches, universal implementation requires an adjustment The response has been overwhelmingly positive, and Dr. Padperiod. Dr. Padua also points out that there remains plenty ua and his team hope to continue the expansion of PRIME to of work to be done in regard to optimizing the screening to an increasingly wide range of people. Perhaps someday in the benefit different types of athletes with different sports-spe- near future sports-related injuries will threaten careers and cific challenges and needs.1 After all, just as the body type of limit aspiring athletes no more. a football player varies from that of a tennis player, a profile detailing the most prevalent injury risks for a gymnast will References not necessarily provide an accurate picture of the physical 1. Interview with Darin Padua, Ph.D. 2/06/19. maladies that might sideline a softball player, or a swimmer, 2. Dexa Use in Sports Medicine. https://www.fsem.ac.uk/ midseason. The same is true regarding the implementation of position_statement/dexa-use-in-sports-medicine/(acinjury-prevention techniques into athletes’ training regimens, cessed Feb. 13, 2018).

3. Physical inactivity a leading cause of disease and disabilwhich must also be tailored to the individual and their sport.

In the meantime, the preventative benefits of PRIME ity, warns WHO. https://www.who.int/mediacentre/news/ testing suggest an abundance of future directions for the releases/release23/en/ (accessed Feb. 14, 2018).

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technology and innovation

The Waltz of Subatomic Particles

By Harrison Jacobs

Image courtesy of Pixabay

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ver since the Industrial Revolution, societal use of nonrenewable resources—most notably fossil fuels—has led to severe environmental consequences, including depletion of the ozone layer and melting of the polar ice caps.

As such, the search for a new source of energy to power the world has caused many scientists to pursue the study of inorganic chemistry in order to create new mechanisms for solar fuel cells. Included among this group is Dr. Jillian Dempsey, an associate professor in the UNC-Chapel Hill Department of Chemistry, whose lab studies proton-coupled electron transfer (PCET) for environmental applications in energy production.

A fundamental component to many energy conversion processes are oxidation-reduction reactions, in which both protons and elecDr. Jillian Dempsey trons are transferred

to various compounds and change the chemical and structural properties of them. PCET is an example of an oxidationreduction reaction, but is unique in that it allows for buildup of multiple redox equivalents used in multielectron reactions, and is done without using high energy intermediates due to the simultaneous transfer of protons and electrons.1 Many of Dr. Dempsey’s projects center on PCET reactions, since PCET enables solar fuel generating reactions by splitting water molecules via electron and proton management.2 In one of her lab’s projects, catalysts are being studied to determine how they can be used to mediate the movement of protons and electrons to create fuel.3 Catalysts are typically composed of a central metal ion that is bonded to charged or neutral molecules called ligands. Researchers in the Dempsey Lab can alter the ligands used for a catalyst by accessing the active site that a reaction will be carried out under. The ability to make such vast alterations causes a wide range of varying physical structures and reactivity for catalysts, which subsequently changes the dynamics of a reaction.

Dr. Dempsey’s research focuses on methods of probing reaction mechanisms like PCET, as the lab looks at “mechanisms of reaction and how, for instance, catalysts mediate the production of fuels, which provides an opportunity to not just evaluate catalysts on bulk metrics (i.e. how fast does it do this reaction, what’s the percent yield), but rather to understand

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Figure 1: Proton-coupled electron transfer mechanisms.

Image courtesy of Proceedings of the National Academy of Sciences of the United States of America. the individual steps.” Having the ability to study intermediates of a reaction—the “mechanistic picture and information of the kinetics of the individual step”—allows for specified stepwise manipulation of a mechanism via the re-designing of a molecule.4 Within the lab, many different parameters can be varied to mediate reactions. Take the production of H2 fuel cells from electrons and protons, for example. To obtain protons, the strength of the acid used in the reaction can be varied.

Similarly, the source of electron transfer occurs through a reductant that can either be strong or weak—the strength of the reductant alters the force of a reaction. Another primary component of reactions are catalysts. As aforementioned, catalysts can be altered by attached ligands, so as to open up access to an active site. Variance among catalysts leads to largescale differences in the mechanisms that a reaction follows.

In a paper published in 2015, the lab discovered that “PCET reactivity that is promoted under electrocatalytic conditions [ultimately] leads to degradation and formation of a heterogeneous active species.”3 The work done by the Dempsey Lab draws from a wide variety of chemistry sub-fields. While most would consider the

technology and innovation

work to be solely inorganic, there are organic components to the research, as the addition of ligands to metal centers is organic synthesis. Furthermore, the lab’s use of spectroscopy, a technique from physical chemistry, allows them to characterize the electrode surfaces of catalysts. Aside from pure chemistry problems related to energy production, the research done in the Dempsey Lab has far-reaching applications to biology, as “syrosine, tryptophan and quinones are known to undergo PCET reactions in nature.”4 In past studies done in inorganic chemistry and within the Dempsey Lab, systems were studied through their reaction to a given stimuli, and how probes were used to decipher the natural mechanism of a reaction. In the future, the lab would like to be able to intentionally control through which pathway a system reacts. Specifically, Dr. Dempsey hopes to “design a new molecule to go through a particular pathway.

[They have] learned that there are PCET reaction pathways that are more energy efficient, as they don’t have high energy intermediates and [therefore] don’t have to pay energy penalties.”4 However, while optimizing a PCET reaction, a common challenge is that, with a lot of systems, one might want to modify a part of a molecule so that something about its function will improve, but sometimes it will inadvertently change another component of the molecule. As a result, it is important to thoroughly study how structural variations arise and how they can be mediated. Furthermore, it is important to decide the order of transferring electrons and protons. Both electrons and protons are sent at the same time to avoid intermediates, therefore resulting in a one-step reaction. This is also ideal because it has one-electron reduced radicals that are reactive and can lead to reactions with different pathways which lead to varying byproducts and degradation.

Dr. Dempsey’s work may someday lead to improving the means by which energy is acquired and used through PCET. The potential in such a venture is endless in the energy landscape and could affect millions of people if properly harnessed.

References

1. Huynh, M. H. V., et al. Chem. Rev. 2007, 107, 5004−5064.

2. Dempsey Group Research. UNC Department of Chemistry.

3. McCarthy, B. D., et al. Chem. Sci. 2015, 5.

4. Interview with Jillian Dempsey, Ph.D. 2/7/19.

“The search for a new source of energy to power the world has caused many scientists to pursue the study of inorganic chemistry in order to create new mechanisms for solar fuel cells.”

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medicine and health

Chemistry Links Metabolism and Medicine

By Madison Miller

Figure 3: Precision nutrition is a science that tailors a diet specific to different groups of people based on their genetics, lifestyle, and environment to defend wellness. Image courtesy of Creative Commons.

D

id you know there are billions of molecules in your body acting as mini fortune tellers that can divulge information on your future health? We can use metabolomics to communicate with these molecules in our tissues to understand what they can tell us about our health.

Formally, metabolomics is the science of analyzing small molecules to study the chemical processes behind metabolism. These small molecules, called metabolites, can be extracted from almost any kind of human sample, such as blood, tissue, or even hair. Once extracted, they are analyzed using mass spectroscopy to develop a graph that displays all of the compounds in a given sample (Figure 1).

In the mass spectrometer, each molecule produces a series of signals that are used to determine the amount of each distinct chemical compound in the sample.

Dr. Susan Sumner, a professor of nutrition at UNC-Chapel Hill and the director of the National Institutes of Health (NIH) Common Fund Eastern Regional ComprehenDr. Susan Sumner

sive Metabolomics Research Core, uses mass spectroscopy in her metabolomics research to understand the links between health and metabolism. Through conducting her research at the UNC Nutrition Research Institute (NRI), Dr. Sumner focuses on looking at different chemical markers that are indicative of an individual’s health. Understanding how a metabolite’s abundance affects health and finding deviances from normal levels of a compound could predict changes in one’s state of health before they get a disease.1 A chemist by trade, Dr. Sumner applies her knowledge of mass spectroscopy in her nutrition research at the NRI. From almost any biological sample—whether it be urine, blood, or tissue from a biopsy—metabolites can be analyzed using mass spectroscopy to compare their abundance in healthy individuals to their abundance in unhealthy individuals.

Groups of compounds in a sample correspond to different phenotypes, which detail patterns of gene expression.

Phenotypes are the center of focus in studies conducted at the NRI—where researchers seek out the chemical characteristics of a given disease. Once a mass spectrum is produced, researchers isolate compounds known to be associated with their target phenotype. The research team then approaches the complicated task of identifying compounds in a phenotype. Oftentimes, “we don’t know what they all are,” says Dr. Sumner.1 To discern signals in mass spectra, the NRI has a library of standard signals. A standard signal is well-defined and consistently produced by a known substance. These sig-

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Figure 1. (Left) Chemical structure of Loxapine drug. (Right) Mass spectrum for Loxapine drug. Images courtesy of Wikimedia Commons. nals can be used as a base of comparison to determine unknown signals.

In a recent study, Dr. Sumner worked with a team that used metabolomics to detect metabolites that can predict prenatal maternal health. Placental abruption is a disorder that occurs during pregnancy characterized by the complete or partial separation of the placenta from the wall of the uterus before a baby is delivered. Premature separation of the placenta decreases the amount of oxygen and nutrients that get to the baby from the mother and can cause heavy bleeding in the mother.2 Though it only affects about one percent of births, it is a serious complication that puts both the baby and mother at risk.3 From previous studies, it is known that certain compounds involved in metabolism are associated with the development of placental abruption. From these known compounds, the study focused on compounds that are naturally present in the body that assist in metabolism, called endogenous metabolites (Figure 2). Blood samples from mothers in their second trimester were analyzed for these endogenous metabolites. Half of the mothers went on to have placental abruptions later in their pregnancy and the other half had no complications. Comparing the presence of 188 compounds in the blood samples, it was found that nine metabolites were present in significantly different concentrations between mothers who went on to have a placental abruption and those who did not.2 Some of the metabolites that differentiated mothers who did and did not have placental abruptions were compounds that can be regulated through the diet.4 This is an important discovery for the NRI as it supports nutrition as a form of preventative healthcare (Figure 3).

More clinical trials need to take place to validate the correlation between metabolite presence and placental abruption. Currently, there are “no means to diagnose placental abruption until it [has] occurred.�1 This research gives the potential to diagnose mothers in their second trimester with high likelihoods of developing a placental abruption later in their pregnancy. The analysis Dr. Sumner conducts on metabolites in biological samples has enabled targeted, molecular descriptions to help predict disease. By analyzing metabolites,

the research also aids in the development of nutrition as a preventative treatment for diseases that develop when certain metabolites are at abnormal concentrations.

Dr. Sumner’s work in using metabolites to predict placental abruption is just the beginning of her path to use metabolomics to predict various diseases and nutrition as method for preventative medicine. While focusing on pregnancy complications and maternal and childhood health, Dr. Sumner continues to look to thousands of tiny compounds to predict and defend against disease.

Figure 2: Glucose is an example of an endogenous metabolite and is the main source of energy in metabolism. This metabolite gives off a unique set of peaks in a mass spectrum.

Image courtesy of Wikimedia Commons.

References

1. Interview with Susan C. J. Sumner, Ph.D. 2/12/19.

2. Placental Abruption. https://www.mayoclinic.org/diseases-conditions/placental-abruption/symptoms-causes/ syc-20376458 (accessed February 22, 2019).

3. Gelaye, B; Sumner, S. J.; McRitchie, S.; Carlson, J. E.; Ananth, C. V.; Enquobahrie, D. A.; Qui, C.; Sorensen, T. K.; Williams, M. A. PLoS One. 2016, 11, e0156755.

4. Precision Nutrition. https://precisionmedicinealliance. org/index.php/precision_nutrition/ (accessed February 16, 2019).

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medicine and health

Silent Attacks

Image courtesy of Pixabay

By Mehal Churiwal

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very year, approximately 200 million adults undergo non-cardiac surgical procedures. However, 10 million of these patients experience cardiac complications during their surgery.1 A heart attack, also known as a myocardial infarction, is one of the most common complications in noncardiac operations. Even though patients are anesthetized during surgery, the body endures acute stress throughout the procedure. The stress of surgery activates the body’s sympathetic nervous system, a set of acute involuntary functions that prepare the body for potential danger. This is the same system that is activated when we feel our heartbeat intensify after getting scared or having an adrenaline rush. This increased heart rate is designed to provide more oxygen so the body has the necessary energy for a “fight or flight” response.2 While the extra bout of energy may be useful to run away

Dr. Priya Kumar

from a bear, it can be dangerous while asleep on an operating table. An elevated heart rate and blood pressure can result in an increased intake of oxygen for the heart muscle, myocardium. Healthy patients can handle the stress, but high-risk patients—like those with diabetes, vascular disease, and heart disease—might not be able to keep up with the large intake of oxygen, therefore leading to a demand-supply mismatch. This lack of oxygen delivery in the face of an increased demand is what leads to a myocardial infarct in 10 million non-cardiac surgical patients annually.

Given that these cardiac complications occur among the presence of many doctors, one would think that they could be immediately detected and treated. In reality, of the 6% of heart attacks that can occur in high-risk surgical patients, two-thirds of them are “silent” without any warning signs or symptoms due to being under the influence of anesthetic medications. Unrecognized damage to the heart muscle in this patient population can lead to poor outcomes after surgery, including death.

Cardiac anesthesiologist, Dr. Priya Kumar, M.D., has been researching interventions to reduce the risk of cardiac events during non-cardiac surgery.3 She is part of an international research team that has been working on a project called PeriOperative Ischemic Evaluation (POISE) for several years, with the goal of identifying and preventing myocardial infarction in non-cardiac surgical patients. The first project, called POISE, focused on medications to control fast heart rates during surgery. The study found that beta blockers, a class of drugs commonly used to control cardiac activity, helped lower heart rates but also lowered blood pressure, which led to an increased occurrence of strokes. Therefore, the researchers proceeded to POISE-2. Patients in the clinical trials were administered clonidine, a medication that slows down the heart and controls blood pressure, and aspirin, which prevents clots from forming in the blood vessels. However, it was found that

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Figure 1: Aspirin did not significantly reduce the risk of having a cardiac event in high-risk patients. Image courtesy of Devereaux et al. 2014.2 clonidine can cause a dangerous blood pressure drop while aspirin can increase the risk of bleeding in these patients. Although aspirin reduced the risk of heart attack, the potentially fatal side effect could not justify the minimally-reduced risk of a cardiac event.4 They have begun their third study, called POISE-3, which is utilizing biomarkers like troponin to identify silent heart attacks. Troponin, which is released by the heart muscle under stress, can help physicians identify and intervene with highrisk patients to prevent further heart damage. Blood loss reduces the capacity to carry oxygen to the heart muscle. In the continued search for a safe and effective approach to prevent heart attacks in non-cardiac surgical patients, POISE-3 focuses on minimizing blood loss during surgery and preventing the blood pressure from dropping too low. POISE-3 is an international study that will ultimately include a total of 10,000 patients who will be monitored closely in the hospital at 30 days and at one year after surgery. Such massive trials would not be possible to conduct independently.5 Dr. Kumar says, “I believe in collaboration; I believe that you need a very strong team. It takes a village to do a study, so you need a strong team that is highly motivated.” It’s impossible for a single center to study a large number of patients in a short period of time to provide meaningful and reliable results. International collaboration among diverse centers is necessary to produce reliable, high quality and unbiased data. Furthermore, fulltime clinicians like Dr. Kumar have most of their time devoted to patient care rather than research. Partnering with researchfocused colleagues is their only opportunity to expand into

the realm of clinical research. Collaborative data spanning a number of centers provides a motivated team and a diverse sample to produce reliable and generalizable conclusions. Not only does clinical research help further the patient’s quality of healthcare, but it also provides physician researchers an avenue to continue to ask questions.

If a patient suffers a heart attack during surgery, they are in a hospital setting in which all the proper resources are available to them. Therefore, it is imperative that these heart attacks are detected and treated promptly with the use of biomarkers like troponin because an ounce of prevention is worth a pound of cure. Dr. Kumar plans to continue her research, constantly asking questions about finding ways to reduce the risk of heart attack during surgery to further improve the outcomes of her patients.

References

1. Devereaux, P. J. Am. Heart J. 2014, 167, 804-809.

2. Devereaux, P. J.; Mrkobrada, M.; Sessler, D. I.; Leslie, K.; Alonso-Coello, P.; Kurz, A.; Yusuf, S. N. Engl. J. Med. 2014, 370, 1494-1503.

3. Graham, M. M.; Sessler, D. I.; Parlow, J. L.; Biccard, B. M.; Guyatt, G.; Leslie, K. Ann. Intern. Med. 2018, 168, 237–244.

4. Kumar, P. Endeavors. https://endeavors.unc.edu/priyakumar/ (accessed February 8, 2019) 5. Devereaux, P. J. PeriOperative ISchemic Evaluation-3 Trial (POISE-3). https://clinicaltrials.gov/ct2/show/study/ NCT03505723?term=POISE3&rank=2 (accessed February 8, 2019).

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“Science is fun. Science is curiosity. We all have natural curiosity.

Science is a process of investigating. It’s posing questions and coming up with a method. It’s delving in.”

- Sally Ride

Image by Ildar Sagdejev, [CC-BY-SA-3.0].

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Spring 2019 Volume 11 | Issue 2

This publication was funded at least in part by Student Fees which were appropriated and dispersed by the Student Government at UNC-Chapel Hill as well as the Carolina Parents Council.

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