Fall 2019 -- The Key To Life: Angiogenesis

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Carolina Scientific

scıentıfic Fall 2019 | Volume 12 | Issue 1

The Key To Life: Angiogenesis A LOOK AT THE DEVELOPMENT OF BLOOD VESSELS full story on page 6 1

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Mission Statement:

Executive Board

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.

Editors-in-Chief Sidharth Sirdeshmukh Sophie Troyer Managing Editor Andrew Se Design Editor Alexandra Corbett Associate Editors Aneesh Agarwal Divya Narayanan Copy Editor Divya Narayanan Treasurer Andrew Se Faculty Advisor Gidi Shemer, Ph.D.

Letter from the Editors: What do we know? How do we know it? Researchers at Carolina use science to answer these fundamental questions. UNC ranks 5th among all universities in the US for research funding, and was also recently awarded the title of 6th Most Innovative University. Carolina Scientific magazine is a celebration of these topical academic achievements and a product of the vast history of research-related accomplishmnets on our campus.

Take a deep dive into this edition of Carolina Scientific to learn more about the cutting edge scientific advances being made on our campus this semester. In this issue, you can read about how bacteria competes for resources in squid (page 8), the impact of climate change on ecosystems and habitats of the Galapagos (page 14), and about modern trends in coronary heart disease (page 34). We hope you enjoy this edition of Carolina Scientific!

-Sidharth Sirdeshmukh and Sophie Troyer

Contributors Staff Writers Kayla Blades Kylie Brown Megan Butler Mehal Churiwal Rajee Ganesan Katie Giffin Eve Golecruz Shriya Haravu Harrison Jacobs Rhea Jayaswal Julie Kim

on the cover

Sarah Kim

Illustrators and Designers Alexandra Corbett Bethany Ebbitt Anushkaa Jain Aubrey Knier Copy Staff Mehal Churiwal Elizabeth Coletti Jesse Dahringer Jasmin Ferido Nisha Lingham

Aayush Purohit

Scientists at UNC use in vivo and in vitro methods of studying the formation and development of blood vessels in the human body.

Full story on page 6. Photo courtesy of Dr. Bautch

Fiona Shaw Maia Sichitiu Ashwin Srinivasan Sylvia Wang

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

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contents

Life Sciences 6

The Key to Life: Angiogenesis

8

Bobtail Squid, Bacteria, and an Illuminating Battle

Sarah Kim

Medicine and Health 26

Eve Golecruz

Katie Giffin

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How Far is Too Far? The Ethics of Personalized Genomics Looking Outside the Bacteria for Answers to Resistance Aayush Purohit

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The Galapagos: Chaos and Discovery in Paradise Assessing the Utility of Conserving Evolutionary History Fiona Shaw

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32

Narrative Medicine’s Place in the Hospital

Kylie Brown

At the Heart of the Trend Mehal Churiwal

Psychology and Neuroscience

Surprises from the Past Shriya Haravu

The Universe at Your Fingertips Megan Butler

Visualizing the Intricate Femtosecond Pump Probe Microscopy Harrison Jacobs

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How Poverty Gets Under the Skin

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Physical Sciences 22

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Julie Kim

Ashwin Srinivasan

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From Your Grandmother’s Health to Yours Rhea Jayaswal

Rajee Ganesan

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Fountain of Youth: How Loving-Kindness Meditation Can Slow Aging

Opening the Black Box: Breaking C-H Bonds via Proton-Coupled Electron Transfer Kayla Blades

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36

The Brain Orchestra

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The Puzzle with infinite Pieces

Sylvia Wang

Maia Sichitiu

Figure 1. Dr. Bautch and her lab attempt to study the role of the nucleus and centrosome in endothelial cell sprouting and vascular remodeling, focusing on how they are able to regulate cell-to-cell junctions, cell polarity, and mechanotransduction. Courtesy Dr. Bautch.

life sciences

the key to life:

angiogenesis H

By Sarah Kim

ave you ever wondered where all your blood vessels come from? How and when are they developed?

What factors affect blood vessel formation and development? These are some of the questions that one may ask when seeking to understand the human body and, more specifically, the circulatory system. As one of the key components in organisms, blood vessels can be found all throughout the body. Arteries are responsible for transporting blood away from the heart, while veins bring blood back from the rest of the body towards the heart. Connecting the network of arteries and veins are capillaries, which are essential in carrying and absorbing oxygen and nutrients. This intricate network of blood vessels is crucial in the human body as it ensures that blood is thoroughly distributed and transported throughout the body to maintain the constant supply of oxygen and nutrients that are necessary for life. Hence, it is equally important

to study where blood vessels come from and to understand the system behind blood vessel formation and development.

Dr. Victoria Bautch, a professor in the UNC-Chapel Hill department of biology and the co-director of UNC McAllister Heart Institute, focuses her research on how blood vessels form during embryonic development, how they change over the course of development, and how they become quiescent, or “settle down,” as we develop into adults. Her lab employs both in vitro and in vivo methods of analysis to study the formation and development of blood vessels. According to Dr. Bautch, the in vitro approach “[helps] us better understand the mechanisms, the underlying molecules, pathways, and processes,” as it is relatively easy to manipulate the systems and gain a general sense of what is going on in blood vessel development, which is called angiogenesis.2 For instance, the mouse embryonic stem cells used in her lab are able to differ-

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Bautch lab has utilized mice that develop mammary tumors as a result of some genes being expressed inappropriately. Her team manipulated genes and introduced mutations in these mice models, allowing her team to identify the important and not so important components of the process. More recently, Dr. Bautch and her team have started to investigate other diseases such as aneurysms, which are “bulges in the blood vessels, usually in arteries, that can lead to hemorrhage, stroke, and disrupted blood flow.”2 Literature results have indicated that some human patients with aneurysms seem to have inherited a trait that made them predisposed to the disease. The causative gene of that trait, SMAD6, turned out to be the gene Dr. Bautch was interested in studying in mice. Although she does not currently have mice models that develop aneurysms, her research on mice lacking the SMAD6 gene confirmed that mice without this particular gene do indeed have problems with blood vessels during development. Her lab also studies other genes and pathways that they believe have a role in developing aneurysms.

Another new and exciting project in Dr. Bautch’s lab right now centers around the role of nuclei and centrosomes of endothelial cells in angiogenesis. Dr. Bautch explained, “endothelial cells in blood vessels are very flat. They are almost like pancakes.”2 She proceeded to describe how cell nuclei protrude like bumps in a row of blood vessels, causing blood to occasionally collide with them. The force at which blood bumps into and flows over the endothelial cells then yields a response in the nuclei. It is this response in the nuclei that intrigues Dr. Bautch, and her lab is studying these responses and how they may affect the development of new blood vessels.

In addition to her hopes to further her research on the role of the nucleus and centrosome in angiogenesis, Dr. Bautch also expressed her excitement to study how the cell cycle affects the ability of endothelial cells to respond to a signal, and how the ways in which cells respond to a signal may depend on what stage of the cell cycle they are in.

She believes that being able to understand the regulation of pathways involved in angiogenesis can yield great applications to repress or activate blood vessel formation in humans. “We are interested in everything,” she said.2 With a plethora of intriguing projects and ideas, it is hard to even imagine what the future holds for Dr. Bautch and Dr. Victoria Bautch her team.

Figure 2. Blood vessel diagram. Courtesy of Britannica.com. entiate into various cell types as they communicate with one another to induce new cell types to form. The differentiated endothelial cells that make up the inner lining of the blood vessels can then be observed to study the different stages of early blood vessel formation. In contrast to the in vitro system of analysis, the in vivo approach involves the use of actual mice and zebrafish models to study angiogenesis. The in vivo approach provides biological relevance that allows Dr. Bautch and her team to test ideas from the in vitro system in real life models. Additionally, genetically disrupting the genes of cells and organisms both in vitro and in vivo allows her lab to observe adverse effects on the signaling pathway, whether that be an increase or decrease in the signaling, or even a complete prevention of the signaling that will then affect how blood vessels form. It is important to understand how too much or too little cell signaling could weaken the organism’s control over the formation and continued development of blood vessels.

“Additionally, genetically disrupting the genes of cells and organisms both in vitro and in vivo allows her lab to observe adverse effects on the signaling pathway, whether that be an increase or decrease in the signaling, or even a complete prevention of the signaling that will then affect how blood vessels form. It is important to understand how too much or too little cell signaling could weaken the organism’s control over the formation and continued development of blood vessels.”

References

Not only is Dr. Bautch interested in the fundamental systems behind the creation and development of blood vessels, but she is also intrigued by more specific questions that arise from the process. Her research aims to study how the process of blood vessel formation is disrupted by the development of pathological situations such as cancer. In the past, the

1. Argosy Publishing, Inc. (n.d.). Blood Vessels: Circulatory Anatomy. Retrieved from https://www.visiblebody.com/learn/circulatory/circulatory-blood-vessels.

2. Interview with Victoria Bautch, PhD. (9/25/19).

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Bobtail Squid, Bacteria, and an Illuminating Battle

By Katie Giffin

Courtesy Flickr Creative Commons

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ost people think of bacteria as an enemy to combat with hand sanitizer and Chlorox wipes. But for the Hawaiian bobtail squid, bacteria are a vital part of everyday life because they rely on a species of bioluminescent bacteria, Vibrio fischeri, for camouflage.1 In return, the bacteria gain a home and protection from predation. This symbiotic relationship turns out to be the perfect model for studying the social lives of bacteria.

Dr. Alecia Septer, an assistant professor in the Marine Sciences department at Chapel Hill, investigates how bacteria compete for space and resources. The bobtail squid is a perfect model for studying bacterial competition because, as she put it, “these bacteria are literally fighting each other for this very sweet home inside an animal.”2 The squid house the bacteria inside a light organ, a cozy cave hidden under the ink sac. The organ is composed of six chambers called crypts, each of which have a tiny tunnel leading in from the ocean. Squid hatch without any bacteria, but within 12 hours, the baby squid are fully colonized by V. fischeri and begin emitting light from their bacterial companions.

There are thousands of strains of the bioluminescent V. fischeri in seawater, yet only a few strains are found inside the adult squid. Research has shown that when juvenile squid are exposed to two different strains of V. fischeri, only one will be present in each crypt of the light organ.3 This is partly because of the anatomy of the squid.

The channel into a light organ is tiny: It can only let in a single cell at a time, so space is limited inside the cozy atmosphere of the squid. The lucky bacteria that get to live there are fed by protein and sugars made by the squid while simultaneously being protected from the horrors of the open ocean. It is valuable real estate and competition is fierce.

However, nobody knew how the bacteria were outcompeting each other. Dr. Septer and her team set out to determine the exact mechanism that allows these bacterial strains to compete for the limited space inside the squid. “There are several ways to compete,” she said. “One strategy… you can just be fast.” While there is evidence that being fast does benefit some squid symbionts, the Septer lab took a different approach by focusing on interference competition. In this method, the bacteria actually interfere directly with another competitor.⁴ To tease out the molecular details of this competition, the researchers first had to identify strains that would outcompete each other.⁵ They isolated several different strains from the wild and incubated them with a well-known strain called ES114. Using florescence as a marker to distinguish between strains, they found 3 strains that outcompeted ES114 and 3 strains that were able to peacefully coexist with ES114.

Next, they tested two potential ways the competitive strains could exclude the other strain. The first hypothesis was that lethal strains simply grew faster and were able to crowd out ES114. However, the growth rates for each strain

“These battles may be tiny, but the impact is huge.”

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these different sites in and on our bodies and when they fight it out, who wins is important. If it’s a pathogen, you’re gonna get sick. If it’s good bacteria you might benefit from it.”

Dr. Septer was also quick to point out that we aren’t the only organisms that will benefit from this line of work: “Understanding how bacteria compete for resources has implications for all sorts of life, not just squid or humans.”

Figure 1. The bobtail squid’s light organ minimizes their shadow at night. Courtesy Dr. Septer. were similar when incubated apart. Maybe the competitive strains were able to reduce the growth rate of ES114? It turns out that over 90% of the ES114 cells were destroyed within just 5 hours of incubation with the other strains. In other words, those bacteria were killers. The question is– how are they killing their neighbors?

One hypothesis is antibiotics, which Dr. Septer described as “diffusible chemicals that kill the bacteria next to them or stop them from growing to get outcompeted.” This mechanism does not require cell-to-cell contact, but other methods of killing competitors do. The researchers decided to separate the two strains with a filter that allowed potential antibiotics to flow through but prevented contact with other cells. ES114 cells could survive this setup, meaning that the bacteria killed through direct contact.

Armed with the knowledge that lethal strains required direct contact to kill, Dr. Septer turned to the genome. A geneticist by training, she discovered two gene clusters in the lethal strains that encode for a molecular weapon called a type VI secretion system. She described this method as a “little molecular syringe.”

The process is surprisingly violent: “When two cells come into contact with each other, one stabs the other one with toxic proteins and then the other one will die within an hour.” Dr. Septer determined that these battles occur within the squid’s light organs. The currently model is that juvenile squid collect several strains of V. fischeri, which live peacefully until the crypts become crowded. Then, the bacterial strains armed with the molecular spear kill their competition and become the exclusive strain within each crypt.

These secretion systems are common in the bacterial world even beyond these squids. “I think bacteria fight all the time!” Dr. Septer said. Her lab is currently in the process of expanding the study of bacterial competition in the ocean where they’ve found promising results indicating the use of similar molecular weapons elsewhere, as well. Dr. Septer is energized by this new line of exploration, explaining that “I think the more we look in the environment, the more we will find these killing mechanisms in diverse bacteria.”

Understanding bacterial competition has important ramifications for human health because these bacterial battles “happen on all animals, including us,” explained Dr. Septer.

“These bacteria are coming into contact with each other in

Figure 2. (Top) Bobtail squid. Courtesy Dr. Septer.

Figure 3. (Bottom) Vibrio fischeri. Courtesy Dr. Septer.

References

1. O’Brien, M.; Walton, M. Glowing Squid. https://www.nsf. gov/news/special_reports/science_nation/glowingsquid. jsp (Accessed September 23rd, 2019).

2. Interview with Alecia Septer, Ph.D. 9/18/19.

3. Sun, Y.; LaSota, E. D.; Cecere, A. G.; LaPenna, K. B.; Valoncia, J. L.; Wollenberg, T. M. Appl. Environ. Microbiol.

2016, 82 (10), 3082-3091.

4. Bongrand, C.; Ruby, E.. Curr. Opin. Microbio.l 2019, 50, 15-19.

5. Speare, L.; Cecere, A.; Guckes, K.; Smith, S.; Wollenberg, M. S.; Mandel, M. J.; Miyashiro, T.; Septer, A. N. PNAS 2018, 115 (36), E8528-E8537.

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How Far is Too Far? The Ethics of Personalized Genomics

By Rajee Ganesan

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ioethics turns up across nearly all fields of medical and biological research; it is a multifaceted field that consists of a variety of problems that people from multiple disciplines can begin to address. How far is too far when editing the genome? How can we effectively place people into risk groups and further personalized medicine? The field was born at the beginning of the 1970s after a series of biomedical debates such as the Tuskegee Syphilis study, the concept of “brain death,” and recombinant DNA technology. The first bioethical research study was funded by the NIH through the Ethical, Legal and Social Implications (ELSI) Program at the National Human Genome Research Institute (NHGRI), and was received with mixed emotions; some researchers were under the notion that bioethics was a waste of resources, while others agreed that as the project entered the uncharted territory of genomics, it was important to take ethical considerations into account. However, bioethics was and is a field that is pertinent to researchers and scientists, and has begun to be studied as such.

Dr. Eric Juengst started out as a Biology major in the ‘70s during the first instance of using recombinant DNA techniques to splice genetic information. Almost immediately, researchers brought into question the growing need for governing bodies and the extent of how these gene-editing technologies should be used. From there, Juengst moved on to complete his Master’s and his Doctorate degree in Ethics at Georgetown University, and eventually went on to work at UC San Francisco’s Medical School within the Division of Medical Ethics,

researching at the frontiers of prenatal diagnosis. He also took some time before working at UNC-Chapel Hill as the Director of the Bioethics program to direct the ELSI program at the NHGRI. Dr. Juengst performs research under the UNC Center for Bioethics here at UNC, explaining that nearly all Dr. Eric Juengst projects in the field begin with some form of fact-gathering and then identifying an unbiased clinical sample or case study to illustrate the conclusion and given facts. From there, the ethical analysis can be performed. However, he does stress that the entire process is not just an individual sitting at a desk – philosophical study and research is made rich by a wide range of opinions and outlooks so collaborators usually meet to discuss and develop an argument together. His research interests include discussion of concepts of health and disease which affects public health policies and genomic ethics. He explains the difference between genomic ethics and general medical ethics and as while medical ethics seems clear, with tenets as to not lie to patients, genomic ethics is driven by new questions in technology and medical issues.

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Courtesy of Flickr Creative Commons

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There are a number of topics that one could potentially searchers, clinicians, insurance companies and employers can focus on in bioethics given the plethora of research topics do with genomic data. currently being studied. Issues Juengst considers to be parFor example, biobanks are huge collections of bioticularly interesting in bioethics logical samples and data that are “Within gene editing, today include gene editing, the used widely internationally—one “eugenomics,” the eugenic genomic revolution, and personthat is particularly popular is the applications of genomics, has UK Biobank. However, there are alized genomics. Within gene editing, “eugenomics,” the eugenic suddenly become an open question a wide range of bioethical issues applications of genomics, has - the line at which the proce- in consideration, such as how suddenly become an open ques- dure goes from preventative to biobanks can be constructed tion—the line at which the pro- editing for genetic advantages and maintained. Currently, there cedure goes from preventative is wide interest in going beyond is murky.” to editing for genetic advantages single gene-testing and creatis murky. Another large issue is ing polygenic risk scores, which dealing with the Genomic Revowould require large amounts of lution, specifically what it means genetic data to build. The US is to have this much genomic and currently attempting to build its genetic information and how to own biobank, the “All of Us” projinterpret it efficiently in a clinical ect spearheaded by the NIH, with setting. Personalized genomics the goal of developing a large also comes into question given bank of diverse groups and poputhe state of the pharmaceutical lations that researchers can use industry, as well as the placement in large genomic data. However, of individuals into risk categories there are a number of issues that and how to accurately and effeccome up, including how to enFigure 1. DNA bands in gel electrophoresis. Courtesy tively stratify patients into these roll patients, what kind of control of Flickr Creative Commons. groups without continuous bias. they will have, what consent they In one of his more recent works, Juengst draws the will have to give, and what kind of information the samples distinction between basic medical care and personalized will return after projects are executed. These are the types of medicine. Personalized medicine was later identified to be questions Juengst hopes to answer in his research. less about tailoring medication for each individual, but inWhen asked what he hopes to achieve with his research stead about categorizing patients into risk groups in order to in the future, Juengst’s describes his hope to provide clarity more precisely diagnose and treat patients. This would later on murky situations for people doing the field work, such as lead to precision public health as the same risk analysis uti- genetic counselors and doctors, and then to potentially influlized in clinical medicine could also be reused in identifying ence practice and public policy by providing sound arguments population risks and where to organize interventions. How- and positions for these situations. He believes that bioethics ever, genomic research remains largely externally regulated will always be useful regardless of the situation, as it provides by the scientific community and federally mandated systems. the ability to anticipate problems before they happen. He also The national academies of science act as spokespeople for plans on beginning future research projects on the bioethics the scientific community, but only hold moral authority of a of using somatic cell gene-editing for preventative measures, peer group, and have no legal or international oversight on as well as potential governance initiatives to regulate research the regulation of clinical research on human gene editing in personalized genomics. until governments establish their own policies. In the United States, there have been laws such as the Genetic Information References Non-Discrimination Act that do provide oversight for what re- 1. Interview with Eric Juengst, M.S, PhD., 09/10/2019.

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Looking Outside the Bacteria for Answers to Resistance

By Aayush Purohit Courtesy Flickr Creative Commons

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obody likes getting sick, but we all definitely love getting better, and oftentimes we can thank wonderous antibiotics for helping us recover. Without a doubt, antibiotics have been one of the greatest human discoveries of all time. Without them, millions would still suffer from extremely high mortality rates due to infectious diseases. Their development and emergence has enabled us to strike a devastating blow to infections on a huge scale. Unfortunately, it did not take long for those same infections to begin retaliating in the form of antibiotic resistance. The bacteria that we had thought would be eradicated for good underwent changes, becoming stronger and more resilient, eventually rising again to continue taking a heavy toll on the human population.

For example, respiratory disease is among the top causes of death throughout the world, largely as a direct result of antibiotic resistance. Substantial research is being conducted to improve current antibiotics, make more accurate models of certain bacteria and drugs to better understand them, and more. However, Dr. Gauri Rao, an assistant professor at UNC’s Eshelman School of Pharmacy, says that these approaches are too simplistic and one dimensional, concentrating solely on the bacteria themselves. She argues that we need to be able to “understand how interactions between the host immune response and the bacteria are changing over time.”1 Dr. Rao believes that if we could potentially take into account the host’s immune response along with the bacteria’s dynamics, we could learn much more about the ways in which infections themselves function and adapt.

It is essential to study the progression of a disease’s dynamics and how it changes and is affected over time by the host—something that has often been overlooked with past research and models—because in a live system like a patient in a hospital, the actions of bacteria and the immune response from the host are not completely static, but are rather adapting and changing in response to one another. For this reason, a key aspect of the work being done in Dr. Rao’s lab involves looking at the mechanisms of infection overtime to properly

understand all the underlying factors that are at play.1 These factors were observed by using blood samples, bronchoalveolar fluid from the lungs (for analyzing lung tissue penetration), and hist o p a t h o l o g y, which provides Dr. Gauri Rao a view of all the different immune system components that were at work through a microscopic analysis of tissue. As a result, they were able to clearly see the specifics of the immune response, such as where and when in the progression of the infection were cells such as neutrophils and B cells, cells that are essential in attacking and destroying invading pathogens, activated.2 Modeling can provide a lot of valuable insight into the dynamics of bacteria and their potential interactions in humans, without actually having to insert the bacteria itself into humans. Dr. Rao’s team developed the first mechanismbased model that works to depict the host-pathogen interactions present over time in a system infected with A. baumannii pneumonia, a bacterium resistant to multiple antibiotics.2 To develop an accurate and reliable model Dr. Rao and her team first collected data by using bacteria extracted from a patient who had been infected, performing analysis in the lab, and then introducing the bacteria directly into the trachea of thelungs of rats to ensure that there would be a higher success rate of infection for the study.1 From this point, there are three main aspects of interest: the bacteria’s behavior, the host’s immune response, and interaction’s effects on the bodi-

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Figure 1. Model of the time course of cytokines, proteins secreted by various immune cells, during the pneumonia infection over 7 days. Courtesy of John Diep. ly environment at the site of infection.2 Putting these pieces immune system activates some cells to defend itself. However, together enables the development of a thorough model that due to conditioned tolerance, translating this data to a model describes the entire experience of the bacteria as it infects the may not be accurate.1 It could turn out that in a human syshost across a certain time period. tem, a far lower concentration of bacteria would be required An important aspect of the experimentation and meth- to provoke the exact same response, thus producing some inodology used by Dr. Rao is that while the way that an antibi- consistencies and incorrect findings. Currently, Dr. Rao’s lab is otic interacts with a pathogen will remain relatively constant looking at bacteria-host interactions in guinea pigs, since their regardless of what kind of a living system it is in, for the most respiratory system and lung pathology shares many parallels part, the host’s immune response could be vastly different to humans as the immune cells and signals that are provoked from one species to another. Laboratory rats are an easy in the furry creatures are very similar to those provoked in our means of working with and testing host-pathogen interac- own bodies, allowing for the creation of an even more accutions, but by this point in time, they have been somewhat rate model for developing human antibiotics.1 conditioned to certain conditions, such that their immune As for the future, Dr. Rao is optimistic about the progsystems are much more tolerant towards dangerous patho- ress being made with pharmacotherapy: “the number of adgens and infection. This can pose some research challenges, vancements that have been made in areas such as biotechnolespecially on the modeling side. For example, it may appear ogy is very high, with examples like laser mass spectrometry that at a certain concentration of bacteria in its body, a rat’s being used for high throughput screening of patients’ samples which help medical professionals identify infections in a clinical setting, enabling them to get a better idea of what they’re dealing with and how antibiotics can be made to defend against those cases. The necessary technology is at our disposal or waiting to be put out. The question that remains is how do we utilize it in the right way.”1 Drug therapy will always be adapting and improving, and with research like Dr. Rao’s, the future will most definitely be healthy.

References

Figure 2. Photo of Acinetobacter baumannii. Courtesy of Matthew J. Arduino at the CDC.

1. Interview with Gauri G. Rao, Ph.D. 09/20/19 2. Diep, J.K.; Russo, T.A.; Rao, G.G. Mechanism‐Based Disease Progression Model Describing Host‐Pathogen Interactions During the Pathogenesis of Acinetobacter baumannii Pneumonia. American Society for Clinical Pharmacology and Therapeutics. 2018, 7, 8, 507-516.

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The Galápagos: Chaos and Discovery in Paradise

Figure 1. Marine iguanas, among the most threatened Galápagos species by climate change.¹

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By Ashwin Srinivasan

ff the coast of Ecuador lies a biological and ecological treasure like no other: the Galápagos Islands. Despite being very well-known by the general public, they are still no less unique or special in terms of their wildlife and habitats. Their famous residents include giant tortoises, marine iguanas, flightless cormorants, and the most northern-living penguins on Earth. In turn, all of these distinctive animals live in an ecosystem made of volcanic lava barrens, forests of giant daisy trees, and underwater algal fields. And finally, all of these ecosystems and their residents exist right on the border of the Equator, the great hypothetical line that divides the planet into two. But despite these special characteristics, the Galápagos and its unique denizens stand to lose everything from global climate entering uncharted territory due to humanity’s actions. UNC-Chapel Hill biology professor John Bruno has been studying the impacts of climate change on the Galápagos in the field, and has made many surprising discoveries, some joyous, some grim.

The waters of the Galápagos are well-known for their calm, mild climate year-round, very unlike the wet, rainy climate seen throughout the rest of the tropics. This climate is what is largely responsible for the great diversity in marine fish seen around the islands, originating from the several major Pacific Ocean currents that merge in the area, each of which brings its own mix of cool or warm water to mingle with that of the others. While something as grand and immutable as the oceans’ daily currents may seem unstoppable, climate

change is defying these rules. As the ocean gets warmer, currents may disappear and/or change direction, essentially blocking the Galápagos’ waters from receiving the essential water they need to be home to so much life. We don’t have to look too far into the past to see the devastation that even a temporary change in the region’s climate can bring. Just over 30 years ago, in the mid-1980s, a particularly large and powerful El Niño turned the water surrounding the Galápagos into a hot soup, eradicating all the coral reefs in the southern Galápagos islands and destroying plankton stocks. This, in turn, led to the possible extinction of the Galápagos damselfish, a formerly abundant little fish that lived only in the waters surrounding the islands, and may have been the first marine fish to be completely wiped out on humanity’s watch. Was this devastation from a natural change in the ecosystem? Or was it an early symptom of human-caused climate change on the islands?

In the modern day, it’s particularly difficult to study the effect of climate change on the islands when there’s no huge event like an El Niño happening, as the effects won’t be immediately obvious to researchers. However, Bruno and his team have studied the underwater ecosystem of algal meadows and the animals that depend on them, such as the islands’ famous marine iguanas. They have uncovered an unsettling but understudied aspect of how climate change affects marine ecosystems: the process of “speeding up”.1 The vast majority of animals living in the Galápagos’ marine ecosystem are ecto-

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Figure 3. Collected samples of green, brown, and red algae Figure 2. A specimen of an undescribed species of red at UNC’s Galápagos Science Center.² algae.² what we all fear is coming”.1 thermic, meaning that their internal temperature regulation is Despite the grim forecasts of Dr. Bruno’s studies, evbased on external sources, and cannot be regulated internally. ery cloud has a silver lining, though it’s up to us to keep the They include animals such as sea turtles, iguanas, most fish, keep the lining shiny and pure. Studies by Dr. Paul Gabrielson, and invertebrates. As the waters surrounding them warm, the a world expert on marine algae and a colleague of Bruno’s, metabolism of these animals also speeds up, meaning that have revealed that many of the marine algae taxa studied they grow, feed, and breed much quicker. This, in turn, leads to

by Bruno’s team are commany more hungry mouths “Studies by Dr. Paul Gabrielson, a world pletely undescribed spefeeding on the ecosystem at a much faster, highly un- expert on marine algae and a colleague of cies, a huge surprise in such a well-studied area as the stable rate. As the unsusBruno’s, have revealed that many of the Galápagos.2 Most of these tainability gets out of hand, there will be less food for all, marine algae taxa studied by Bruno’s team taxa were formerly either hastily synonymized with leading to many animals of are completely undescribed species, a huge other algae species from sea and sky dying in a futile attempt to adapt. Such surprise in such a well-studied area as the elsewhere on Earth, or were genuinely never assigned a changes and others from cliGalápagos.” name before. Dr. Bruno has mate change have the abilcollected specimens of many of these species and donated ity, according to Dr. Bruno, to “fundamentally change the Gathem to phycologists (algae specialists) such as Dr. Gabrielson lápagos’ marine food web”.1 Marine animals and algae that are so that they can eventually receive a proper species descriptypically found in tropical areas and have ranges restricted by tion.

Unfortunately, as with almost all Galápagos taxa, many barriers of cool water may be able to overcome these barriers of these algae taxa are highly threatened by climate change, as the water warms, colonizing areas they never had before even before they’ve been described to science.

But this issue and “tropicalizing” the local ecosystem, pushing out many of won’t go away if we respond to this crisis by doing nothing, the species who have lived in those cool ecosystems for thousands, if not millions, of years. “If we don’t find better ways to making empty gestures, or blaming others for a problem that reduce our carbon emissions”, Bruno says, “we have little hope we all contribute to, all while climate-threatened taxa go exof staving off the social, economic, and ecological impacts of tinct one-by-one. The denizens of the Galápagos, shaped into such unique forms over millions of years of evolution, do not deserve to die off in such a pointless and anticlimactic way.

For their sake, and ours, we need to fight back like never before in order to preserve the world’s biodiversity and prevent a mass extinction. In the end, we can only achieve things if we stand up and act for the future of our planet.

References

Figure 4. The Galápagos Damselfish: An extinction from a natural event? Or Galápagos’ earliest recorded climate casualty?³

1. Bruno, J. (2018, October 25). Troubled waters in the Galápagos. Retrieved from https://www.washingtonpost.com/ news/theworldpost/wp/2018/10/25/Galápagos/.

2. Interview with Dr. Bruno (September 19, 2019).

3. Simons, E. (n.d.). The Fish We Never Knew - The Weird, the Rare and the Ugly. Retrieved from https://baynature. org/biodiversity/Galápagos-damselfish/.

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Courtesy Flickr Creative Commons.

life sciences

Assessing the Utility of Conserving Evolutionary History

By Fiona Shaw

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lass jars filled with countless tiny creatures are lined up the future.3 She explains, on shelves. Various species of zooplankton can be seen “We can look upon some growing, developing, feeding, some swimming quick- gradient of…water abilly around their environments, others floating around idly. Dr. ity to the rainforest and Caroline Tucker, an assistant professor in the Department of we look at rainforest trees Biology, runs a busy, thriving lab at UNC-Chapel Hill. Dr. Tucker and you see that…they received her Ph.D. from the University of Toronto before work- have traits which are reing as a visiting researcher at Stanford University and did post- ally adaptive to that endoctoral fellowships at the University of Colorado Boulder and vironment and that those the CNRS in France.1 At UNC, she now examines ecological things are general. They questions in two main areas. One area of her research involves go beyond…knowing how the functional traits of zooplankton individuals alter spe- about specific species.

Dr. Caroline Tucker cies’ interactions within communities.2 Functional traits can be We can just say, ‘if a comexplained as visibly apparent traits of an organism that can munity looks like this, it’s probably from this environment’… influence the organism’s fitness. Additionally, she studies how and so then we can make predictions about what’s going to evolutionary history can aid in conservation biology.2 happen to different systems or species based on just looking Dr. Tucker’s work is both significant and critical at a time at their characteristics.”3 This work is performed in her lab by when the future of speraising communities of zoocies’ diversity is unknown “Though the importance of species for the plankton and creating miand threatened by climate or small replicas future environment or to fulfill human needs crocosms, change. In an interview with that mimic the conditions cannot always be predicted, using her, she talks about how of local aquatic environher research on functional evolutionary history information can help con- ments, she explained.3 Pretraits examines their utility vious ecological research in servationists be strategic about which as a more efficient way of this area was focused more understanding species and on categorizing species, but species they direct their efforts towards.” making predictions about studying functional traits growth, reproduction, and provides more information survival.3 She explains how she is particularly interested in than can be obtained by just studying species, Dr. Tucker says.3 examining human impacts on communities and hopes that Another branch of Dr. Tucker’s research involves evoluby relating how communities respond to these impacts to the tionary history, which can act as a valuable tool in conservatraits present in the community, it is possible to make gen- tion efforts. Evolutionary history can be explained as the hiseral predictions about how natural systems will change in tory of all of the evolutionary changes that have happened, or

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ons.

Carolina Scientific as a branching set of relationships among species. Dr. Tucker also discusses how conservation efforts are often focused on protecting either rare species or sites with the most species, but species with long or unique evolutionary backgrounds— which might also be associated with accumulation of great variation in form and function over the course of evolution— may be especially important to protect.3 Though the importance of species for the future environment or to fulfill human

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examines the effects of climate change on ecological networks and evolutionary responses.3 Fitting into the broader discussions about the current and future effects of climate change, Dr. Tucker said, “the reason people are excited about using traits is because the hope is they allow us to make predictions. And, making predictions right now, for ecology, is just so important because everything is changing so fast.”3 This statement is incredibly relevant coming just days after

Figure 1. (Left) Microscopic image of algae. Courtesy of Dr. Tucker.

Figure 2. (Right) Imaging of algae (Chlamydomonas) in microcosms. Courtesy of Dr. Tucker. needs cannot always be predicted, using evolutionary history information can help conservationists be strategic about which species they direct their efforts towards, she says.3 Dr. Tucker explains, “By looking at relationships between species and understanding where they are on the tree of life, we can say something about how many millions of years of evolutionary history are going to be lost if we lose this place or…if we lose this species, we are going to lose a hundred million years of evolution.”3 In a 2019 article, Dr. Tucker’s team expanded on this area of study by discussing the major arguments surrounding the importance of measuring evolutionary history and explaining how it relates to phylogenetic diversity: the amount of evolutionary diversity that is present in a specific phylogeny or species.⁴ They explained that evolutionary history, as measured by phylogenetic diversity (PD), can serve as an additional resource in guiding the preservation of biodiversity.⁴ For example, a species family may have a very rich evolutionary history, so it would be especially valuable to protect it because of the amount of phylogenetic diversity it represents.

Dr. Tucker is now also exploring a new area of research which

Rosenburg et al. reported in Science that North America today has nearly 3 billion fewer birds than it did just 48 years ago.⁵ Given the current state of the environment, reports such as this will likely become more prevalent. Dr. Tucker’s work, and the work of other ecologists, is incredibly important right now and will only continue to be so as scientists strive to understand the incredible diversity of life that is still left on earth and how to best protect it.

References

1. Tucker, C. ResearchGate. 2019.

2. Caroline Tucker: Ecologist at UNC. http://carolinemtucker.com/ (accessed September, 2019).

3. Interview with Caroline Tucker, Ph.D. 9/10/19.

4. Tucker, C. M.; Aze, T.; Cadotte, M. W.; Cantalapiedra, J. L.; Chisholm, C.; Díaz, S.; Grenyer, R.; Huang, D.; Mazel, F.; Pearse, W. D.; et al. Biol Rev. 2019, 94, 1740-1760.

5. Rosenberg, K.V.; Dokter, A.M.; Blancher, P.J.; Sauer, J.R.; Smith, A.C.; Smith, P.A.; Stanton, J.C.; Panjabi, A.; Helft, L.; Parr, M.; et al. Science. 2019.

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physical sciences Courtesy of Flickr Creative Commons

SURPRISES FROM THE PAST

By Shriya Haravu

T

he ideas of changing the past and controlling the future are undeniably intriguing. These far reaching goals have constant reminders: from the well renowned classic Doctor Who, the Marvel movie Antman and the Wasp, and H.G. Wells’ Time Machine, which all shine light on this intriguing concept. However, so much of the essence of time travel is overlooked.

As Einstein proved many years ago, the universe is shaped by a fabric of space-time. While it may not be intuitive, Dr. Gerald Cecil at UNC-Chapel Hill has brought attention to the fact that time travelling occurs when collecting astronomical data. The speed of light is so quick, that residents of Earth almost consider it a negligible amount of time.

However, even with a speed of 3.0x108 m/s, the time it takes light to travel becomes more defined and apparent over long distances like those separating our Milky Way from another galaxy.

At the heart of the observational astronomy and modeling done by Dr. Cecil and the team is the discrepancy in time between measurements of the occurrence of a black hole’s flare at the center of our galaxy and the occurrence of the event in its own frame of reference.

The figurative telescope to this black hole’s activity was a stream of clouds and gas being ripped off of a nearby galaxy in orbit around the Milky Way. This

brighter-than-expected stream of gas, also known as the Magellanic Stream, whose various properties were determined with telescopes like Hubble, was the driving force behind the research.1,2 The results of the project have been astounding, revealing that energy dispersed by Sagittarius A*’s (the Milky Way’s central black hole) flare at the center of our galaxy about 3.5 million years ago caused ionization of particles within its field of influence.1,2 Its area of influence is spread like a cone, hence the term “ionized cones” is used to describe the flare’s area of impact.1,2 The Magellanic Stream was used as evidence not only to affirm that Sagittarius A* must have exploded but also to determine when the explosion happened on the universe timescale. The team’s analysis supports the occurrence of this landmark event and takes a quantitative approach to understanding and grounding the initial qualitative observations of increased brightness or luminosity of the stream.

The Big Bang, which occurred billions of years ago, is thought of as our universe’s time of most enthralling large-scale energy release, electron recombination, emission of light, and activity. However, our galaxy 3.5 million years ago was evidently still alive with action. While Sagittarius A, specifically, is not as active anymore, our universe may

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not be as void of exciting cosmic activity as one may expect.

This black hole has been at the center of the Milky Way galaxy since the beginning of the universe. As a continuous stream of gas fed into it from its surrounding accretion disk, Sagittarius A* was triggered to release large amounts of energy and radiation.1 How was the flare discovered? The Magellanic Stream happened to be in the area of influence and its analysis thus provided evidence of the flare which is also known as the Seyfert explosion when referring to this specific flare that occurred in the very center of our Milky Way. Dr. Cecil’s use of the term “mirror”1 helps visualize the role of this Magellanic stream. As a light reflector, it provides information about the intensity of light being emitted from the galactic center half a million years ago. The gas from the stream possessed a luminosity much higher than expected, even for ½ a million years ago, and it was understood that there must be some significant source of energy. The only plausible source was found to be the flare of the supermassive black hole mentioned above.1,2 At the core of the research was analysis of data taken from multiple ground and space-based telescopes like Hubble, each of which was able to capture different niches of radiation.1

Carolina Scientific Hubble was essential to the capture of UV radiation and thus the absorption spectrum of the ionized cones in the Magellanic stream.1 An absorption spectrum indicates which wavelengths of light are absorbed by the stream, providing greater insight into its chemical composition.

For example, the intensity of a spectral line corresponding to Carbon would tell the ratio of different ions of carbon, I.e. carbon atoms with different numbers of electrons stripped off, present in the gas.1 Spectroscopy performed on the ionized cones led to an understanding of the Carbon, Silicon, and Nitrogen ion ratios.1,2 The team developed Mappings, a modeling program, from this understanding to find the correct parameters of gas density, temperature, and radiation such that each of these dependent

the reactions that take place from a projection of photons on a gas cloud with given specifications.1,2 The Magellanic stream lies 0.25 million light years away from Earth and another 0.25 million light years away from the galactic center, meaning the light intensity of Sagittarius A* initially recorded by researchers was from about half a million years ago.1 Intensive calculation modeling was employed not only to determine parameters relating to intensity and brightness of the Magellanic Stream, but also to extrapolate the data over longer times and to conclude that the explosion took place 3.5 million years ago.1,2 The modeling was the basis for a series of conclusions not only identifying the Seyfert explosion as a source of

physical sciences field.1 Dr. Cecil and his team of researchers have now found an all-star: the supermassive black hole flare which took place 3.5 million years ago at the center of our galaxy and can be detected from anywhere in the Milky Way. Even so, there is more to explore.

Dr. Cecil mentioned multiple future courses of action. Among them are goals to refine the Mappings program and study the inner workings of black holes in more detail with respect to how they accrete matter, remain active, and derive their energy.1 The main aim of the team as they look to the future is the need for more telescopic data from the UV range, especially from the Hubble Space Telescope which is nearing the end of its lifetime with no immediate successor in line.1 The use of such instrumentation,

Figure 1. (Left) The line almost tracing out a circle is representative of the Magellanic Stream, which is being pulled into the Milky Way. The stream can be seen overlapping with the ionized cones (black hole’s area of influence). Figure 2. (Right) In this model created by the team, the ionized cones (blue regions) can be seen extending from the center of the Milky Way. The ionized cones are the regions affected by the explosion. The black hole’s area of influence is cone shaped rather than a perfectly straight jet because of “blocking” from the hole’s accretion disk. Both images courtesy of Dr. Cecil and team.

elemental ion ratios would result.1,2 An understanding of the gas parameters is important because they correlate to electron recombination times and thus provide insight into the rate of change of brightness of the stream, allowing for more quantitative analysis and traversal of time.1 Other evidence supporting the existence of an energizing source includes ground telescope data indicating regions of ionized hydrogen 5-6 times higher than they would otherwise be.1,2 The magnitude of the supermassive flare needed to produce the corresponding spectrum and brightness was found using Mappings, which simulated

radiation but also determining when the flare occurred and how long it lasted.1 Since the increased intensity of the stream could have been attributed to other sources of radiation, a thorough investigation of these possibilities was carried out. All except the supermassive black hole flare in Sagittarius A* were deemed insufficient. For example, ultraluminous x-ray sources did not penetrate far enough to impact the stream’s luminosity.2 Until recently, more common and well-known fountains of radiation, like dying stars and the ultra-luminous X-ray sources discussed above, were thought to be some of the biggest players on the

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shared worldwide, makes this project demanding not only in modeling and analysis but also in planning and implementation. As can be seen, the major concerns for the future arise from the means of collecting data.

References

1. Interview with Cecil Gerald, Ph.D., 9/24/19 2. Bland-Hawthorn, Joss, and Philip R. Maloney, and Brent Groves, and Ralph Sutherland, and Magda Guglielmo, and Wen Hao Li, and Andrew Curzons, and Gerald Cecil, and Andrew J. Fox, Draft-Research Paper, The LargeScale Ionization Cones in the Galaxy, 2019.

Figure 3. Picture of the moon taken by a Skynet telescope which could be uploaded to Afterglow.

Courtesy of Dan Reichart.

physical sciences

the universe at your fingertips

By Megan Butler

T

he days of astronomers staring into telescopes, wondering what they are looking at and what it all means, are numbered. Thanks to Dr. Dan Reichart and his system of fully automated telescopes called Skynet, scientists are getting to know the universe from the comfort of their laptops.

What started as a project to observe a specific astronomical event turned into an international network of robotized telescopes used nightly by hundreds of researchers and students.

From cultivating interest in astronomy to making important discoveries, Dr. Reichart and his team have revolutionized the way we can study and understand space.

Skynet began as an investigation into gamma-ray bursts (GRBs), the brightest electromagnetic events known in the universe caused by massive exploding stars that “live hard and die young.”1 If you are quick enough, the burst leaves a remnant of visible light – unfortunately, humans are not that quick. Luckily for astronomers like Dr. Reichart, technology is. He figured if we can open a telescope with the push of a few buttons, why can we not write code to completely automate that process? His mission became creating a network of completely robotic telescopes that observe space in ways we cannot.

As a graduate student at The University of Chicago in the late 1990s, Dr. Reichart studied GRBs since they were “the hottest things in astronomy back then.”1 He was initially trained as a modelist, figuring out how to best interpret data.

However, he decided that instead of solely predicting or analyzing astronomical events, he wanted to discover them. Despite being “really bad” at making telescopes, he was lucky (and resourceful) enough to have funding to hire professionals who could build his vision.1 In 2000, he predicted with his advisor that GRBs would be detected farther than anything

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else in space. He came to UNC-Chapel Hill in 2002, started Skynet, and then, in 2005, he and his students successfully identified the most distant explosion in the universe – a GRB – using Skynet and other UNC-affiliated telescopes.2 After that discovery, the money flew in, and Skynet spread to other places in the United States, Canada, Europe, and Australia. A subset of Skynet is called PROMPT, consisting of the highest-quality telescopes at the best viewing sites.

The main PROMPT telescope location is the Cerro Tololo InterAmerican Observatory in the Chilean Andes (Figure 1), a twomountain observatory that often functions above the clouds (Figure 2). Skynet shares the mountains with other governmental and international organizations – a new telescope in the works for Cerro Tololo is going to map the entire sky every three days.

Skynet has hundreds of users every night. As a result, the research team has developed a smart system that organizes all of the requests to get everyone the best data possible. Housed here at UNC, the hub of the network receives input from the main portal and then communicates with the other telescopes across the world. Since its conception, hundreds of thousands of researchers and over 50,000 students have used Skynet and PROMPT telescopes. Now, Dr. Reichart is still the director and main fundraiser for Skynet, so he spends a lot of time writing grants. Although they sell use-time to get some of the money to run the network, annual costs are $300,000 to $350,000 on average. However, the benefits to the scientific community are priceless. The international group of researchers using data from Skynet and PROMPT (meaning he is not writing all of his 750 plus listed papers) publish in peer-reviewed journals about every three weeks.

Carolina Scientific Dr. Reichart’s mission is split between research and education, so the Skynet team runs numerous educational programs. Skynet’s role in an actively collaborative project, Innovators Developing Accessible Tools for Astronomy (IDATA), is to make their systems compatible with blind and visually impaired students and deaf and hard of hearing students. All of Skynet’s interfaces can perform screen reads, and the research team has been working on image sonification. On their newly updated Afterglow 2.0 interface – Skynet’s web application for making fundamental measurements from Skynet images (Figure 3) – there is the option to sonify pictures. The different light sources function as a piano, with low-frequency sounds indicating the left side of the image and high-frequency on the right, which then moves up the photo. Blind and visually impaired students can quickly learn how to identify image profiles from the sounds.

Using Skynet equipment, Dr. Reichart personally leads a radio astronomy education retreat, showing students the

physical sciences

comes in?” and then said “making the big discoveries.”1 According to him, those discoveries just keep coming. The last major finding was a year and a half ago in detecting gravitational waves–disturbances moving through spacetime at the speed of light, originally predicted by Albert Einstein in his theory of general relativity. The waves are usually impossible to see because they mostly occur when two black holes merge, which is undetectable. In this special case, two small and dense neutron stars merged and created a flash, and Skynet was one of six groups to discover the flash simultaneously.

It was the first visible light confirmation of gravitational waves.

This paper was the biggest one ever written in astronomy: it has over four thousand authors, about one-third of all practicing astronomers.3 The most recent developments in Dr. Reichart’s research lie in preparing for the next visible light confirmation of a gravitational wave event. The team has developed a program called the Campaign Manager which, once a neutron

Figure 1. (Left) PROMPT telescopes at the Cerro Tololo Inter-American Observatory, Chile. Courtesy of Dan Reichart.

Figure 2. (Right) An above-the-clouds view of the Cerro Tololo Inter-American Observatory in Chile. Courtesy of Dran Reichart.

invisible world of supernova explosions and star formation (Figure 4). He also spearheads the undergraduate educational program called Our Place in Space!, developing laboratory sequences for UNC’s Astronomy 101 labs. Once he introduced the almost entirely Skynet-based curriculum, lab enrollment increased by about 150%, lecture by 100%, and major enrollment for the Astronomy track by 300%. There are now professional educational researchers studying Skynet to determine why it has been so impactful to incorporate into classrooms, especially for Astronomy 101, which Dr. Reichart calls “the last science course most people ever take.”1 Therefore, the study of Skynet-based education is less about traditionally emphasized learning gains and more about attitude gains – do students leave the class with a positive attitude towards astronomy and science as a whole? The preliminary studies have shown that using Skynet was one of only two things in a list of many college course elements (office hours, textbooks, active learning, etc.) that had a positive impact on attitude. As Dr. Reichart says, “There’s something about it [Skynet] that’s special.”1 That certainly seems to be the case for researchers, students, and teachers alike.

When asked what his favorite part of his research is, Dr. Reichart replied, laughing, “Other than when the money

star merger is detected, can communicate to all of Skynet instantly. It can decide how long specific telescopes need to expose and how that changes throughout the merger, readapting the entire network to best record the event. Dr. Reichart also hopes to open Skynet to the public in a cost-recovery mode, “not to make a profit, but imagine if you can log in, and for pocket change, take a few pictures with professional quality telescopes at some of the world’s best observatories.”1 Not only could that inspire widespread interest in science and astronomy, but it could provide an influx of data from those who typically would not have access to technology like Skynet. If Skynet does go public, then anyone could make the next big astronomical discovery.

References

1. Interview with Daniel E. Reichart, Ph.D. 9/18/19.

2. Haislip, J. B.; Nysewander, M. C.; Reichart, D. E.; Levan, A.; Tanvir, N.; Cenko, S. B.; Fox, D.B.; Price, P. A.; Castro-Tirado, A. J.; Gorosabel, J.; et al. A photomeric redshift of z = 6.39 +/- 0.12 for GRB 050904. In Nature 2006, 440, 181-183.

3. Abbott, B.P.; Abbott, R.; Abbott, T.D.; Acernese, F; Ackley, K.; Adams, C.; Adams, T.; Addesso, P.; Adhikari, R. X.; Adya, V. B.; et al. Multi-messenger Observations of a Binary Neutron Star Merger. In ApJ 2017, 848, L12 (59 pp).

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physical sciences

visualizing the intricate: femtosecond pump probe microscopy

By Harrison Jacobs Courtesy Flickr Creative Commons

"What I find exciting is doing things that people haven’t done before. In the context of our research, that’s building instrumentation. Being able to ask and answer questions that will change the way that we think about materials."

Dr. Papanikolas n many undergraduate-level courses in the sciences, models to interpret physical systems are idealized and simplified to allow for better understanding of a given material for students. However, in reality, systems are often complex in nature and difficult to characterize due to high amounts of microscopy and frequent variability. Within

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the field of material sciences and physical chemistry, Dr. John Papanikolas and his group work on creating instruments that can effectively characterize a given interaction which may otherwise have been difficult to do.

When first arriving at UNC-Chapel Hill, Dr. Papanikolas used ultrafast spectroscopy to describe the dynamics of complex systems.1 In a broader sense,

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spectroscopy is a way to illustrate matter through excitation or emission of electromagnetic radiation, which yields a spectrum of light separated by color that corresponds to energy levels.2 Specifically, ultrafast spectroscopy involves extremely quick lasers that send pulses to a sample measured on very small time scales by a detector.2 Through experimentation, Dr. Papanikolas realized that the technology commonly used in ultrafast spectroscopy was not up to par with the specificity required with nanoscale samples, especially as complexity of a system increases with heterogeneity.1 Heterogeneous mixtures are difficult to quantify dues to the diverse content that is not uniformly distributed within the material. As such, Dr. Papanikolas sought to develop a new technology that gave both temporal and spatial resolution to be able to connect the dynamics of the system to its structure.

Over time, Dr. Papanikolas implemented a two laser pulse technique— on the order of femtoseconds—in a microscopy mode, wherein a pump

Carolina Scientific pulse of 425 nm wavelength is initially emitted to excite electrons to the conduction band of a material, creating electron hole pairs.1 This first laser pulse causes a photoinduced transparency which excites an electron to the point of electron transfer within a band. Following, there is a “pump-probe delay” in which the band relaxes and the electron falls back into the valence band (Figure 1). After, the researcher sends a probe pulse of 850 nm to measure pulse intensity, which can be correlated to known standards in characterizing the material.

This, in turn, has led to more focused measurements, as measurements can be taken on shorter time scales and with greater certainty than before. Such a system can allow for examination in different locations of a structure, like the middle section versus the end, or the straight region versus the bending. The applications of this technology are multifold, but one in particular that is pertinent to material sciences is the bending of small microstructures of macroscale matter. When bending occurs at a microscopic level, there is an increase in irreversible defects in materials and

Figure 2. Bending of material at microscopic level. Non-uniform energetics of a material are due to such phenomenon, as there are high levels of variation in energetics within straight and curved regions found dispersed throughout the material. Courtesy of Dr. Papanikolas. straining of molecules, both of which alter the energetics of the material (Figure 2).

The work described above has been done with elements such as silicon and germanium and will lead to layered materials studies so as to correlate electronic dynamics from pump-probe experiments to different kinds of defects in materials.3 In the case of silicon (Si), nanowires are used as metal-insulatorsemiconductor transistors, which helps with the energy efficiency of electronics due to coupling the effects of an insulator and a semiconductor.⁴,⁵ Si wires have also been shown to be effective in device reconfiguration, in solar cells, and as anodes in lithium-ion batteries.⁴ Further, understanding a given metal’s properties shows variations amongst and within materials and leads to new questions and answers about materials in ways that people have not thought of before.

When asked about his research, Dr. Papanikolas said, “What I find exciting is doing things that people haven’t done before. In the context of our research, that’s building instrumentation.

Being able to ask and answer questions that will change the way that we think about materials.”3 He went on to say

References Figure 1. Excitation and subsequent relaxation of electron in two laser pulse technique. During relaxation, electron’s intermediate states vary by material, which can aid researchers in describing the dynamics of the system.

Courtesy of Dr. Papanikolas.

physical sciences

that the study of materials is “constantly evolving as we learn about new phenomenon and new ways of describing matter and chemical systems,” informing scientists as to how size and shape affect various properties.3 The potential for novel understanding is multifold, as materials make up everything in life.

Whether its understanding how the large metal PET-CT scan heats and cools to allow for radiation treatment, to how a bullet proof vest can absorb a bullet, the importance of material properties is critical to making sense of the ability for a material to perform a given task.

Dr. Papanikolas has been at UNC since 1997. Since then, he has taught thermodynamics, quantum chemistry, and graduate level courses. He says that while not directly related to his research, the same ideas hold true that modeling systems is an ever-changing process in both the classroom and lab. As his research allows for further understanding of materials, his students gain a deeper knowledge of the class through similar use of mathematical and physical models. If any follow in his footsteps, we may one day be able to characterize the vast unknown within the field of material sciences.

1. Papanikolas, JM. Visualizing Carrier Dynamics in Semiconductor Nanowires using Femtosecond Pump-Probe Microscopy. UNC Department of Chemistry seminar 2019 2. Kulesa, C. What is Spectroscopy? University of Arizona.

3. Interview with Papanikolas, Ph.D. 9/13/19.

4. Mikolajick, T; Weber, WM. Chapter 1 Silicon Nanowires: Fabrication and Applications. Semantic Scholar 2019 5. Mudusu, D. RCS Advances. 2017, 7, 11111-11117.

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physical sciences

Opening the Black Box:

Breaking C-H Bonds via Proton-Coupled Electron Transfer

By Kayla Blades Courtesy Flickr Creative Commons Carbon-hydrogen bonds—or C-H bonds—are pervasive in organic molecules as carbon is the basis for all organic molecules and compounds. Organic molecules are essential because they can be found in almost all living matter: they even can be found in the cells that make up our body. C-H bonds in particular are unique in that they are strong, nonpolar bonds that are highly unreactive.

The search for ways to break C–H bonds in order to alter their functionality has been a highly active area of research in the scientific community. Current methods of breaking C-H bonds, also referred to as C-H cleavage, typically involve highly reactive species that often produce several side products.

The creation of these side products makes it difficult to tell if C-H bond cleavage has been achieved.

Dr. Erik Alexanian is a professor for the UNC-Chapel Hill Department of Chemistry whose research group focuses on reaction development and chemical synthesis. Dr. Alexanian searches for more effective methods of C–H bond cleavage and has recently published research involving the alkylation of an aliphatic C-H bond.

Reactive intermediates such as free radical species are commonly used in hydrogen atom abstraction of C–H bonds.

However, these highly reactive species can produce a variety of side products. Dr. Alexanian’s research was initially geared towards investigating the use of a catalytic system, which involves increasing in the rate of the chemical reaction by decreasing the amount of energy required to obtain the desired products. The catalytic system would be used to create a tuned nitrogen-centered radical species capable of selective C-H bond abstraction. In other words, the catalytic system is designed to have more predictability in what C-H bond was abstracted.

But his research changed course when his team discov-

ered that the catalytic system could cleave the bond by itself.

What the group discovered is that proton-coupled electron transfer (PCET), a type of chemical reaction, could be used to cleave the C–H bond without involving a highly reactive free radical.

In this C–H bond PCET process, an iridium catalyst with a coordinated phosphate base Dr. Erik Alexanian simultaneously removes an electron and a proton from the substrate C–H bond, which lowers the reaction barrier to cleavage of the C-H bonds. This new elementary step to C–H bond cleavage offers a mild, catalytic method of activating unreactive bonds and limiting undesired side reactions compared to previous approaches. In these studies, the Alexanian group used the catalytic process to alkylate hydrocarbons. Dr. Alexanian noted that the most important part of this research is the process by which the catalytic system breaks the C-H bond due to its broad implications in synthetic chemistry and catalysis.

Chemists can often see both the reaction and the products, but the reaction mechanism is often harder to determine. One of the most significant challenges Dr. Alexanian faced in his research was trying to determine the mechanism of the bond cleavage. Although he was receiving the desired result, “what actually happened in the flask was a black box”.2 Dr. Alexanian worked in collaboration with Dr. Robert Knowles and his group in the Department of Chemistry at Princeton University to determine the reaction mechanism of this new process (Figure 1).1 During his research, Dr. Alexanian

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Figure 1. Mechanism for C-H Alkylation via Multisite-Proton-Coupled Electron Transfer. Courtesy Dr. Alexanian. discovered that removing the sulfonamide–which was intended to produce a reactive nitrogen-centered radical–had no effect on the outcome of the reaction, and the yield actually increased when it was not present. This revelation showed that the mechanism they were studying had a different elementary step, which was essential in understanding the reaction that is taking place and how to optimize it. Through the use of time-resolve spectroscopy, the groups were able to study the

physical sciences

mechanism of the reaction. A significant part of this research was the site-selectivity of bond cleavage because of the pervasiveness of C–H bonds in organic substrates. They were able to determine that bond cleavage would most likely to occur at weaker C-H bonds or more acidic sites. For example, they found that catalytic cleavage of C–H bonds at the benzylic position was very effective.

Dr. Alexanian aims to continue the development of new catalytic transformation that uses C–H bond cleavage to install different functional groups in a range of hydrocarbons.

One of the ways he intends to accomplish this is by working with Dr. Leibfarth, another professor in the Department of Chemistry at UNC. They plan to use this catalytic system of bond cleavage to introduce functionality to commodity polyolefins, which would give them the capability to change the properties of the polymer.

The largest implications of this research program are the opening the black box of the mechanism of C-H bond cleavage and the discovery of a new elementary step for catalytic C–H cleavage. This unlocks a new world of possibilities for a range of important hydrocarbon functionalization under mild conditions. This capability can alter the chemical properties of simple and complex hydrocarbons that are among the most widely available compounds for chemical synthesis.

References

1. Morton, C. M.; Zhu, Q.; Ripberger, H.; Gautier, L. T.; Toa, Z. S. D.; Knowles, R. R.; Alexanian, E. J. J.Am.Chem. Soc. 2019, 141 (33), 13253-13260 2. Interview with Erik J. Alexanian, Ph. D. 09/20/19

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medicine and health

Fountain of Youth: How Loving-Kindness Meditation Can Slow Aging

By Eve Golecruz

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dvertisements are full of products that “make you look young again” or tips on how to stay fresh at age 50. And apart from heavy medications or an intense gym-and-diet complex, there aren’t a lot of viable methods to combat the byproducts of aging. But what if there was a solution that requires less physical effort than going to the gym daily, or a solution less expensive than having to buy hundreds of dollars’ worth of cosmetics? UNC Psychology professor Dr. Barbara Fredrickson investigates the effects of maintaining positive emotions and how it could lead to reducing biological aging in one of her most recent studies on loving-kindness meditation.

What is the biological effect of positive emotion on the human body, in addition to its social and mental effects?

Why do we have positive emotions? Dr. Fredrickson investigates these questions with her team under the Positive Emotions and Psychophysiology (PEP) Laboratory.1 The research program aims to explore the effects of regulating emotions and the different strategies which hone these emotions toward positive trajectories.2 In a 2019 study, Dr. Fredrickson and her team explored how the loving-kindness meditation for positive

emotions shows correlation with reducing telomere attrition.3 (Figure 2) Telomeres are the DNA caps located at the ends of each chromosome which protect the genome from degradation or fusion during genetic recombination.4 Attrition occurs when these protective caps diminish, resulting in aging and age-associated diseases, such as cataract and osteoporosis.4 Dr. Fredrickson and her team want to study the relationship between positive emotions and its biological effects, focusing specifically on how certain meditation alters telomere attrition.

Mindfulness meditation is described as focusing on the awareness of the mind (thoughts) and body (breathing). It is the observance and acceptance of emotions without particularly trying to feel other, more positive ones.2 In contrast, loving-kindness meditation focuses on directing social cognition, such as empathy, and cultivating specific, positive emotions as opposed to openly accepting one’s present emotions.3 This type of meditation assumes that “there are certain [emotional] states worth cultivating, like kindness and warmth and openness” and that these states are brought via extending these states toward others.2

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Dr. Fredrickson and her team conducted a twelve-week study in which participants between 35-64 years old attended a 6-week meditation workshop, sepaDr. Barbara rated into mindFredrickson fulness meditation and loving-kindness meditation.3 The loving-kindness meditation was fundamentally taught towards “warmth, kindness, and social connection,” while mindfulness meditation focused on “facilitate[ing] viewing one’s experience with more clarity and objectivity.”2 Each group learned their assigned practice and were encouraged to do individual meditation, having to record daily assessments of their emotions and the number of times they meditated. At the conclusion of the study, blood samples of the participants were obtained to measure telomere attrition.

After compiling the results, Dr. Fredrickson and her team found that telomere attrition occurred as expected between those in the control and

Carolina Scientific mindfulness meditation group, while the loving-kindness group had buffered and reduced the magnitude of attrition.2 In addition, participants in the experimental groups reported no adverse effects, and the duration and frequency of meditation among the three groups increased in the order: control, mindfulness meditation, and loving-kindness meditation.2 (Figure 2) This finding could be fundamental in opening the doors to understanding the evolutionary aspect of positive emotions in an individual and how to obtain them for improved biological function, specifically towards reducing telomere attrition. Shorter telomere lengths have been found to be associated with numerous diseases like vascular dementia and coronary artery disease, since attrition essentially destroys the protective barrier that slows cells from dying.4 Apart from pharmacological solutions, research into meditation and positive emotions could prove to be a natural reductant to telomere attrition, bypassing the need for medication and chemical agents. Her research could be the stepping stone to learning how to naturally reduce cellular aging, along with the health effects and diseases that result from telomere attrition.

While substantial evidence suggests that loving-kindness meditation indeed has an effect in reducing telomere attrition, some researchers question the mechanism by which meditation produces this biological effect. In a previous study, Dr. Fredrickson inves-

Figure 1. Retrain your brain to prioritize positive thoughts. Courtesy Google Creative Commons.

tigated the difference between the two types of meditation, finding that lovingkindness meditation increases positive emotions while mindfulness meditation only reduced negative emotions.5 The data from this study showed that there was no reported difference in positive emotions between the two methods.2 Yet interestingly enough, loving-kindness meditation was associated with reduced telomere attrition than mindfulness meditation.3 From these observations, Dr. Fredrickson and her team wondered how they can explain the difference in biological effects with respect to what emotions the subjects felt and how much they practiced each meditation technique.5 While loving-kindness meditation did result in reducing telomere attrition, the current evidence is unclear as to why the meditation had those outcomes.3 Dr. Fredrickson and her team hope to continue exploring telomere attrition through psychological and behavioral differences, and have begun this next step by involving new samples which are more focused on individuals who faced early life adversity.2 Overall, she states that meditation is one tool of many that people use to “develop new skills for regulating their emotions” and “chang[ing] their [positive] emotion trajectories over time.”2 And while her most recent study has opened the prospects for linking loving-kindness motivation

References

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Figure 2. The graph compares the measured telomere length from the start of the study to the end in each participant, grouped by the experimental group. Note the significant difference in change in telomere length (TL) between the lovingkindness meditation group (LKM) and both the control and mindfulness meditation group (MM).³ Courtesy of Nyungen et al.

and positive emotions with reduced telomere attrition, Dr. Fredrickson hopes to continue her research encompassing the different techniques that regulate positive emotions, answering the same questions that stemmed from her research in meditation and emotions.2 Her research into attrition foreshadows the prospect of studying positive emotions.

And although the mechanism itself is yet to be fully understood, we’re one step closer to finding a true solution to slowing biological aging.

1. Research. (2019). Retrieved from http://peplab.web.unc.edu/research/. (accessed 09/25/19) 2. Interview with Dr. Barbara Fredrickson, PhD. 09/25/19 3. Nguyen, K. D. L., Lin, J., Algoe, S. B., Brantley, M. M., Kim, S. L., Brantley, J., … Fredrickson, B. L. (2019). Corrigendum to “Loving-kindness meditation slows biological aging in novices: Evidence from a 12-week randomized controlled trial” [Psychoneuroendocrinology 108 (2019) (October) 20–27]. Psychoneuroendocrinology. doi: 10.1016/j.psyneuen.2019.05.020 4. Babizhayev, M., Kasus-Jacobi, A., Vishnyakova, K., & Yegorov, Y. (2014). Novel Neuroendocrine and Metabolic Mechanism Provides the Patented Platform for Important Rejuvenation Therapies: Targeted Therapy of Telomere Attrition and Lifestyle Changes of Telomerase Activity with the Timing of Neuron-Specific Imidazole-Containing Dipeptide-Dominant Pharmaconutrition Provision. Recent Patents on Endocrine, Metabolic & Immune Drug Discovery, 8(3), 153–179. doi: 10.2174/1872214808666140608145810 5. Fredrickson, B. L., Boulton, A. J., Firestine, A. M., Cappellen, P. V., Algoe, S. B., Brantley, M. M., … Salzberg, S. (2017). Positive Emotion Correlates of Meditation Practice: a Comparison of Mindfulness Meditation and Loving-Kindness Meditation. Mindfulness, 8(6). doi: 10.1007/s12671-017-0735-9 6. Barbara Fredrickson. (0AD). Retrieved from https://www.wlu.edu/questioning-passion/speakers/barbara-fredrickson.

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FROM YOUR GRANDMOTHER’S HEALTH TO YOURS

By Rhea Jayaswal Courtesy of Flickr Creative Commons Shiny rings, music boxes, outlandish self-portraits – Grandpa and Grandma may have passed on some unique heirlooms. Recent findings show that you may also inherit something else from your grandparents: epigenomic alterations.

To study the biological processes that control epigenetics, Dr. Folami Ideraabdullah focuses on maternal vitamin D deficiency (VDD), a worldwide problem without a clearcut explanation for its mechanisms or the magnitude of effect upon the child. Pregnant women are also at a higher risk for VDD. Global prevalence rates range from 7% in South Africa to 100% in parts of Northern Europe.¹ Numerous studies have suggested that maternal VDD results in poorer child health, ranging from direct effects such as low birth weight to worsened neurological and metabolic health later in life. The central question in Dr. Ideraabdullah’s lab is: how? Studies have demonstrated the adverse effects of maternal VDD, but the underlying genetic processes of how maternal diet connects to later life outcomes remain unclear.

Recently, her lab has focused on a possible epigenetic link.

An individual’s genome, or genetic makeup, is an important determinant of who they are, from appearance to health, both determined at conception from both parents’ DNA. The result is etched into stone with little exception. Unlike the genome, the epigenome is responsive to influence from the environment, and can affect whether or not certain genes are expressed. While the genome is strictly inherited from mom and dad, the epigenome instead regulates how those genes

are used by the cell to impact health and disease.

One key influence is diet. “Availability of nutrients can affect epigenetic states,” Dr. Ideraabdullah explains. ² Nutrients play a key role in epigenetic functions through a variety of processes, including donating essential compounds or even acting as signaling molecules that affect how genes are expressed.

One of the most widely studied mechanisms by which Dr. Folami Ideraabdullah the epigenome regulates the genome is DNA methylation, the process of attaching a methyl group – a type of chemical compound – to DNA.³ Doing so can either activate or repress a gene, comparable to an on/ off switch. The epigenome can be altered throughout an individual’s life, but certain epigenetic markers are established during development and stably maintained into adulthood.

In order to shed light on the possible connection between insufficient vitamin D and epigenetic outcomes, researchers used mouse models.⁴ The mice allowed for a controlled physical environment and genotype. Because they metabolize the vitamin similarly to humans, they provide a clearer comparison with our species. Two different strains of

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mice were fed either a control diet with vitamin D or a diet and converting the nutrient into a usable form for the devellacking in vitamin D. The female mice were fed their dietary oping child. treatment for several weeks before mating and throughout Ultimately, this body of research emphasizes the necesgestation and weaning in order to ensure vitamin D deple- sity of regulating maternal vitamin D intake, and more broadly, tion. Their children and grandchildren were fed normal rodent the significant role maternal nutrition plays in epigenetic and chow, so that only the original mice lacked vitamin D in their phenotypic outcome in offspring over multiple generations. diets. Researchers measured DNA methylation states, body For Dr. Ideraabdullah, the work continues. These inweight, and body composition in all generations. strumental findings are the result of the combined efforts of Dr. Ideraabdullah’s lab was already the first to show herself, undergrads, graduate students, postdocs, technicians, that VDD during development alters adult offspring’s epigen- and collaborators from other labs. Their research has made etic state, but this most recent research expanded on those strides, but there are still many questions she looks to answer findings further. at the growing in“This preliminary evidence is part of a growing body of reearch show- tersection of geIn the experimental group with the ing that environmental influences as far back as grandparents can netics and nutridetermine the epigenomic alterations carreid today. This mice lacking vitation. min D, the first and emerging concept, known as multi-generational epigenetic inheriCurrent resecond generation search examines tance, is changing the way we look at the health of individuals.” have altered DNA whether other methylation states(Figure 1). In other words, two successive common environmental factors exhibit similar long-term ingenerations showed altered epigenetic states that coincided fluences on offspring epigenome. Particularly, the lab focuses with differences in body weight and body composition. on certain pesticides and deficiency of methyl donor nutrients “Without additional deficiency, just being deficient dur- ¬– for example folate, methionine, and choline. This research ing that one initial [developmental] stage can affect children will provide a better understanding of how early-stage enviand your children’s children,” says Dr. Ideraabdullah. This pre- ronmental disruptions lead to heritable disease. liminary evidence is part of a growing body of research showAnother potential area of exploration involves zebrafing that environmental influences as far back as grandparents ish. Because environmental insults during development such can determine the epigenomic alterations carried today. This as VDD can occur regardless of species, different animals have emerging concept, known as multi-generational epigenetic unique potentials for study. Zebrafish provide just one develinheritance, is changing the way we look at the health of in- oping model in the field – they reproduce quickly, produce dividuals. Additionally, researchers found that the offspring’s large populations, and provide access to more developmental response to Vitamin D depletion depended more upon the stages than mice. maternal and grandmaternal genotype than those of the faRodent models are continuously improved to better thers, theoretically because the mother is the one providing mimic human populations, especially the genetically divergent strains developed here at UNC, known as the Collaborative Cross – the same kind used in this study. Dr. Ideraabdullah hopes that, alongside her central research, her lab can help generate improved animal models for studying environmental exposures. Primarily, the overarching goal is to improve people’s long-term health through early interventions, such as additional or personalized vitamin D supplementation based on one’s genes.

“As a geneticist, I think about generations of people,” says Dr. Ideraabdullah. By focusing not only on the relationship of health to an individual’s epigenome, but also parents’ and grandparents’, Dr. Ideraabdullah takes a new approach to illuminating the biological processes driving the developmental origins of health and disease.

References

Figure 1. DNA methylation states for two different genes in Grandchildren mice from either the control (CON) line or lacking vitamin D (LVD) line. Differences are statistically significant and specifically linked to grandparent of origin as opposed to diet. 1 and 2 refer to different crossbreeds of mice.⁴ Courtesy of Xue et al.

1. Ideraabdullah F.Y.; Belenchia A.M.; Rosenfield C.S; Kullman S.W.; Knuth M.; Mahapatra D.; Bereman M.; Levin E.D.; Peterson C.A. J Endocrinol. 2019, 241(2), R65-R80.

2. Interview with Dr. Folami Y. Ideraabdullah, PhD. 9/23/2019.

3. Xue J.; Gharaibeh R.Z.; Pietryk E.W.; Brouwer C.; Tarantino L.M.; Valdar W.; Ideraabdullah F.Y. Epigenetics. 2018, 13(9), 959-974.

4. Xue J.; Schoenrock S.A.; Valdar W.; Tarantino L.M; Ideraabdullah F.Y. Clin Epigenetics. 2016, 8, 107.

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How Poverty Gets Under the Skin

By Kylie Brown

Courtesy Flickr Creative Commons

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ake a moment to reflect on the stressful moments in life; running late for work, cramming for an exam, undergoing a drastic life change, and many more. If you thought all those stressful times stopped impacting you the moment your stress was relieved, think again. It turns out that any kind of negative social experience can affect the brain and lead to negative health outcomes, and for individuals, such as those with low socioeconomic status, who experience chronic stress, the impacts on health and the brain are tremendous.

Dr. Keely Muscatell, an assistant professor in the Department of Psychology and Neuroscience, runs the Social Neu-

In her review paper Socioeconomic Influences on Brain Function: Implications for Health, Dr. Muscatell examines how socioeconomic status (SES) impacts neural activity and the resulting health consequences. There are various avenues through which SES may influence brain function, including psychological and neighborhood factors. There are also correlations between SES and neural activity in response to factors such as stress and reward processing. Low SES individuals experience chronic stress and have fewer opportunities to engage in a healthy lifestyle. As a result, neural activity in certain regions of the brain is heightened, which may lead to long-

“Lower SES individuals follow a set of norms that include greater engagement in social interactions and a more empathetic nature.

However, studies have found that these traits may actually make such individuals more susceptible to negative health outcomes such as higher levels of inflammation.” roscience and Health lab where they investigate how social experiences impact physical health and well-being. There is a specific focus on understanding the pathways through which social experiences can influence health, particularly the brain.

Dr. Muscatell’s research is important because it demonstrates how negative social experiences like stress can “get under the skin” and impact the brain.1

term health risks including greater production of cortisol and overconsumption of drug and tobacco products.2 Research of this nature is significant because it connects “broad societal level issues like economic inequality or poverty to things that are happening inside people’s heads and inside their bodies” by adding a biological mechanism through which these negative health outcomes occur.1

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In order to reach such meaningful conclusions, Dr. Muscatell and her lab synthesized existing neuroscience literature exploring the pathways connecting SES, brain function, and health .Three notable pathways were identified; psychological stress, cultural orientation, and neighborhood contexts (Figure 1).2 Results of various studies found that individuals from lower SES environments exhibited greater responses to psychological stress, especially in respect to inflammation and the autonomic nervous system. Lower SES individuals follow a set of norms that include greater engagement in social interactions and a more empathetic nature. However, studies have found that these traits may actually make such individuals more susceptible to negative health outcomes such as higher levels of inflammation.2 The pathway of neighborhood contexts demonstrates that low SES individuals have fewer opportunities at a community level to promote positive health behaviors. This lack of opportunity is due to food deserts, a lack of public facilities to encourage physical activity (such as parks), and a greater prevalence of drug and tobacco Figure 1. The connections between socioeconomic status (SES) and health outcomes. products.2 While these pathways link SES to neural activity and health, research synthesized by Dr. Mus- dividuals, negative health behaviors like overeating are prone catell and her team can provide further evidence on the ef- to develop, resulting in long-term risks to a healthy lifestyle.

One of the most fascinating methods mentioned in fects of certain stimuli such as threats/stress and reward on this paper was the process of gathering evidence linking SES brain function. Certain regions of the brain are activated in and stress.

Dr. Muscatell and her team described a study by response to threats/stress. For example, increased activity in Gianaros and colleagues in which individuals were shown a the amygdala corresponds to an increase in cardiovascular, series of angry and neutral faces while researchers measured inflammatory, and cortisol (stress) responses. These responses reactivity in the amygdala. The results showed that individuals can lead to negative health outcomes in the long term, such as who deemed their parents as having a lower social standing cardiovascular disease.2 SES also influences how the brain reshowed greater reactivity to the angry faces. Muscatell and sponds to rewarding her lab confirmed these results by demonstrating a negative stimuli. While heightcorrelation between family SES and amygdala reactivity to anened activity in the gry faces.2 In other words, a lower family SES corresponded to reward center of the a heightened response to angry faces in the amygdala. brain reduces stress The most recent development associated with this in the short term, in project is the process of successfully bringing together many the long term it can different puzzle pieces of information in order to connect such result in difficulties seemingly different subject matters as neuroscience and SES.1 controlling behavDr. Muscatell hopes that her research can be used by iors such as eating other scientists to “improve health equity and promote better in excess. Therefore, people who struggle health outcomes.”1 Although science can take a long time to with obesity must eat evolve from a basic demonstration to being implemented in more than the aver- people’s lives, the ultimate goal of her research is to be used to age person in order improve the health of society as a whole. to reach the same “‘reward threshold.’”2 References As stress continually 1. Interview with Keely Muscatell, Ph.D. 9/18/19. stimulates low SES in- 2. Muscatell, A.. N.Y. Acad. Sci. 2018, 1-19.

Dr. Keely Muscatell

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Narrative Medicine’s Place in the Hospital

By Julie Kim

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edicine is more than healthcare or care of health; it is care of person.

Medicine can serve as an archive of records—or stories—of patients’ symptoms, pain, injuries, and progression of life. Yet, in modern practice, there is a tangible absence of emphasis on narratives, which can be defined as subjective accounts of one’s life experiences and subsequent interpretations. As some medical professionals strive to push the envelope of interdisciplinary practice, it is difficult to ignore the necessity of integrating the more abstract, multifaceted humanities into the starkly rigid, scientific realm of lab coats and sterile instruments. Physician, author, and professor Terrence Holt is an esteemed contributor to the growing movement of embracing the “art of medicine.”

An emeritus professor of Geriatric Medicine and an associate professor in Social Medicine, Dr. Holt was fundamental in establishing an interdisciplinary MA program in medicine and literature at UNC-Chapel Hill. Furthermore, Dr. Holt is a prominent author, with his book Internal Medicine standing out among his numerous publications as a mark of how narrative and medicine can not only coincide, but complement one another. Internal Medicine is the manifestation of one of Dr. Holt’s primary interests: how narrative offers insight into the physician’s career and can potentially break down narrow stigmas that represent medical professionals today. It is a book that blurs the lines of fiction and non-fiction, written in the form of a memoir from the perspective of a hospital resident. The book points to the benefit of storytelling and story writing for doctors. Holt explains that writing stories helps him to “make sense of things…”1 It is important to mention Holt’s argument that the “way we are taught how to… understand a story gives the impression that a story is this device that the writer uses to hide ideas in—in the same way a nurse might stick a pill inside a cup of pudding.”1 But Holt says, “that’s not really it at all.”1 Instead, all that he tries to achieve in writing a story is “some sense of coherency. It’s out of that coherency that people are able to find what we think of as meaning…”1 Internal Medicine is a product of Dr. Holt’s attempt to process the hospital, his role in it, and the ways he could improve upon patient-care, an exercise that other physicians could greatly benefit from if integrated into their training.

Narrative holds a definitive place in the training of future medical practitioners. Holt makes the striking statement, “I think a doctor that has done nothing but study science throughout his or her undergraduate career is crippled from the start and may never recover.”1 He says that the study of exclusively STEM subjects is “good training for being a technician… but not for anybody who has to deal with human beings.”1 Holt emphasizes the threat that such training poses for physicians and patients alike, as the principal feature of medicine is its all-encompassing focus on dissimilar human beings, and intervening in their lives. Hence, “you can’t just treat people… as if they’re terms in an equation or reagents in a piece of glassware. They are not going to behave predictably,”1 Holt explains. A physician who seeks to provide the most appropriate care for individuals in need, must “have all the tools for understanding people that [one] can possibly lay hold on.”1 These tools, Holt believes, “are most powerfully developed, most diverse and rich in their potential in the humanities.”1 In addition to helping physicians interact with patients in the most favorable ways, education in narrative can aid in a physician’s own mental health and journey of medical practice. In Internal Medicine, Holt says, “these are stories about how you take a human being through the process—the very inhuman process—of becoming a doctor and how you do that and still retain your hu-

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Figure 1. Pencil. Courtesy Flickr Creative Commons.

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Figure 2. (Left) hospital records. Figure 3. (Right) transcription. Both images courtesy of Pexels.com creative commons. manity.”1 Holt’s statement is a striking reminder that often prove to be consequential to physicians. Holt underlines that physicians, in the midst of receiving constant criticism for apa- writing one’s story “in a form that feels true, that feels honthy, carry their own need of empathy. est and yet makes sense”1 is challenging, but vital. Ultimately, The limitations of physicians are actively acknowl- articulating one’s experiences in a cohesive and reflective edged in writing, and a physician’s own written deliberation manner is a rewarding practice, especially for physicians. The of medicine’s restraints can aid in improving approaches to insight that is attained, Holt explains, “is the most important patient-care. Holt emphasizes that one primary limitation thing any clinician can bring to the patient encounter.”1 Thus, to physicians is the inevitability of death. The omnipresence a self-aware physician can be confident in responding to the of death in the hospital is portrayed in the chapter “Orphan” challenges of patient care. Holt highlights the value of physiof Internal Medicine when the narrator says “I was assigned cian introspection, which can arise from actively composing to the oncology service. I hated it. Any service on which pa- written accounts—or stories. Holt says, “so that’s what I think tients routinely die during morning rounds upsets me.”2 Al- the utility of storytelling might be for doctors—story writing.”1 though medicine has developed immensely over the last few From mortality to limited statistical evidence, to the absence decades, Holt emphasizes that physicians cannot guarantee of a single-defining statement of medicine, there are plenty of always knowing “the right move”: a challenge which “simple, limitations surrounding healthcare. The abstraction however, technological advance[s]”1 cannot help. Consequently, the can be embraced with the incorporation of the humanities, “right” solution or outcome varies with each case in medicine. such as literary training.

Holt states that another limitation of evidence-based mediThe insight that Dr. Holt provides from the perspective cine is that it is based upon statistical analysis, and statistics of a practicing physician and writer is significant to modern can only describe behaviors of large groups. Thus, evidence- medical education, practice, and the growing interdisciplinbased medicine is severely restricted, as it is difficult to know ary academic field of the health humanities. Holt says that the whether a patient is appropriately described by the available role of narrative in training future physicians should be found statistical information. This limitation is seen in Internal Medi- in the undergraduate education, and that even at the admiscine as the narrator describes patient Muriel Wallace, saying, sions process, medical schools “should be looking for more “It’s impossible to read how the body came to be there, what people with diverse backgrounds that are strong in the hulife it left behind. Just… the slow accumulation of data as labs manities.”1 After all, according to Dr. Holt’s words, “medicine is and vital signs and consults and imaging fill up the chart, tell- an applied humanity.”1 Holt also believes that medical schools ing nothing about the person they surround.”3 Another limita- would “do better to admit people with serious backgrounds tion of medicine is its defini- in literary studies,”1 citing how “the medical curriculum is too tion—or lack thereof. Holt crowded as is”1 to require medical literature courses. Lastly, says that one paradox of Holt claims that stories can be found everywhere.1 An intemedical education is that gral part of every life and every personhood, narrative should one “cannot define what a be all the more accepted into the medical education of future good doctor is…”1 He says clinicians. that the goals of medical care are frequently unclear References but one thing that is clear is 1. Interview with Terrence Holt, MD, Ph.D. 9/24/19. that “medicine remains to a 2. Holt, T. Orphan. In Internal Medicine: A Doctor’s Stogreat extent an art far more ries; Liveright Publishing Corporation: New York, 2015; pp than anything else,”1 and 59. with the training that is nec- 3. Holt, T. When I Was Wrong. In Internal Medicine: A essary for effective writing, Doctor’s Stories; Liveright Publishing Corporation: New Dr. Terrence Holt the utility of narrative can York, 2015; pp 123.

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at the heart of the trend

By Mehal Churiwal

Courtesy Shutterstock Commons

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he heart is the center of the chest, the organ of central focus, the pump that is responsible for circulating blood to every cell within the body -- however, even though the heart pumps blood to the rest of the body, it also needs that blood for its own proper functioning. Thus, blood is supplied to the heart by three major arteries called the coronary arteries. Dr. Sameer Arora, a cardiology and preventive medicine internist who is also completing his master’s degree in epidemiology from UNC-Chapel Hill’s Gillings School of Global Public Health, conducts research focused on disease associated with these coronary arteries. Complications in these arteries are often highly prevalent in populations, like heart attacks caused by a blockage of an artery. One primary component of his research is on coronary disease, one of the most common and highly studied forms of heart disease.

From past research, we know that overall heart disease, specifically coronary artery disease, has gone down over the past two to three decades in the United States. However, other research and studies show that the prevalence of diabetes

risk factors are risk factors for heart disease”.1 To test and understand this hypothesis, he analyzed massive amounts of data from the Atherosclerosis Risk in Communities (ARIC) study, the second-largest population-based cohort study, which has been going on in the United States since 1987, providing one of the world’s most valid and Dr. Sameer Arora appreciated data sets.

ARIC not only investigates the causes of atherosclerosis but also measures how risk factors, medical care, and outcomes

“Heart disease is the most common cause of morbidity and mortality in the world, especially in the United States.” and hypertension has actually gone up in young populations.

Dr. Arora and his colleagues hypothesized that the trends in coronary disease may not be equally distributed; he “wanted to see whether these trends of diabetes and hypertension have actually transferred into heart disease since all these

vary by age, sex, place, and time. By collecting widespread community surveillance and cohort data, ARIC has collected data about heart disease from 400,000 adults that has been used to structure many clinical guidelines and publish over 1,800 scientific articles. Looking across the entire population,

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Carolina Scientific Dr. Arora categorized patients between 35 and 54 years old as young and between 55 and 74 years old as elderly, then looked at trends over the past 20 years in coronary disease.

He found that the overall trends for coronary disease have declined when specifically focused on older populations, but not in younger populations. Obviously, there was a suspicion that this is due to the prevalence of diabetes and hypertension rising in younger populations. However, in order to further study the trend, he categorized younger individuals into male or female. Surprisingly, he found that in young males, there is a decline corresponding with the older generation, but not in young women. Dr. Arora came to the conclusion that there is a concerning trend in young females that is giving rise to this overall trend in young populations of increasing coronary artery disease.

Generally, males are considered to have a higher risk of heart disease than women due to genetics. Through his clinical knowledge and experience, Dr. Arora says that “there is a general perception that if a woman comes in with chest pain, [physicians] might not think that it is a heart attack”.1 Thus, he wanted to study whether women are being treated fairly. Indeed, he found that young females were not as likely to be treated by evidence-based medications or by coronary angiography (a procedure in which the patient goes to a catheterization lab to get blockage cleared by having a stent inserted into the coronary artery) for heart attacks. Other social determinants of health, such as poverty and psycho-social stressors, are also known to be more prominent in females. The study also found that women are more likely to have diabetes and hypertension in the overall population, putting them in a higher risk profile and therefore underscoring the importance of proper preventative care. More importantly though, re-

medicine and health

“We should actually formulate guidelines specifically focused on women because the risk factor profile is different, the way they are treated is different, the way they present is different, so maybe the guidelines for females should be a little different for females as compared to males.”

differences and accumulate funds to further study these disparities, their underlying causes, and other associated factors such as poverty or psycho-social stressors. More specifically, he is advocating that “We should actually formulate guidelines specifically focused on women because the risk factor profile is different, the way they are treated is different, the way they present is different, so maybe the guidelines for females should be a little different for feFigure 1. (A) There is a decline in heart males as compared attacks among men but not among to males”.1 Such a women. (B) The population of heart project is also neattack patients has been aging for both cessitated by the sexes. (C) However, the percentage of lack of representaheart attacks attributable to younger tion in research, as populations has been increasing, with “65-70% of the pathe greatest increases in women. Courtients in clinical tritesy Dr. Arora. als for heart attacks are traditionally men, so there has to be more equality in favor of more female recruitment in these clinical trials.”1 Advocating for more equality in clinical trial recruitments would likely translate to the formation of guidelines specifically for women and improve awareness regarding their differences. “For undergraduates who are interested in clinical research, this is a good subject to research. Heart disease is the most common cause of morbidity and mortality in the world, especially in the United States”.1 Even if one is not interested in clinical research, there are always ways to be involved in community outreach and work with the American Heart Association to get this message across and promote heart health in female populations.

search proves that the presentation of heart attacks is slightly different in females. Men are more likely to present with very typical symptoms--an exertional chest pain that goes away with rest and then slowly progresses back again. Females are more likely to present with atypical symptoms; they might have chest pain at rest that goes away and comes back unexpectedly. Dr. Arora’s study re-emphasizes the message that physicians have to see the entire picture, not ignoring atypical symptoms, especially in women.

Going forward, Dr. Arora’s priority is to get this message out to people, that such trends and disparities exist. He advocates outreach in the community to talk about these

1. Arora, Sameer. “Carolina Scientific.” 14 Feb. 2019.

2. Arora, Sameer, et al. “Twenty Year Trends and Sex Differences in Young Adults Hospitalized With Acute Myocardial Infarction.” Circulation, U.S. National Library of Medicine, 19 Feb. 2019, www.ncbi.nlm.nih.gov/pubmed/30586725.

3. “Atherosclerosis Risk in Communities (ARIC) Study.” National Heart Lung and Blood Institute, U.S. Department of Health and Human Services, www.nhlbi.nih.gov/science/ atherosclerosis-risk-communities-aric-study.

4. “Sameer Arora, MD.” School of Medicine - Family Medicine, Department of Family Medicine, www.med.unc.edu/ fammed/directory/sameer-arora-md/.

References

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Figure 1. Emboidery brains. Courtesy of Flickr Creative Commons.

psychology and neuroscience

The Brain Orchestra

By Sylvia Wang

T

here are as many neurons in the human brain as there are planets in the Milky Way galaxy.1 Each neuron communicates with thousands of other neurons through small electrical currents. These electrical currents sync up to produce brainwaves.2 But what if these brainwaves were too strong? What could that mean? And how would we go about resyncing the brain back to a more normal state?

These questions are the basis of the research conducted at the Carolina Center for Neurostimulation,3 directed

by Dr. Flavio Frohlich. Dr. Frohlich’s interest in electrical stimulation had its early starts in engineering. “When you build something, you don’t want it to oscillate,” says the neuroscientist. “Something that goes back and forth makes no sense.

It’s hard to control. Why would the brain generate these really strong rhythmic signals that can be measured through the skull? Definitely not for our convenience.”4 Prior research in the field of brain electrical activity has shown that patients with psychiatric illnesses, such as depression, exhibit abnormal brain waves.5 Dr. Frohlich and his team hypothesize that altering these brainwaves to a more normal state through weak electrical stimulation could result in an

“The openness of the clinicians should really be highlighted in this.

I think it’s also a bit unique about Carolina.

The idea that I can go to a world expert in mood disorders and say, ‘You know I have this crazy idea about weak electric Dr. Flavio Frohlich currents, do you want to work with me and help with this study?’

It requires a certain climate and a certain openness of the clinical researchers, and that fills me with a lot of gratitude.”

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urtesy mons.

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Carolina Scientific improvement in clinical symptoms.

And in an early clinical trial, the data showed just that.6 Dr. Frohlich’s research utilizes a specific type of neurostimulation called transcranial alternating current stimulation, or tACS for short. Electrodes are attached to specific locations on the scalp and weak electrical signals are used to target specific brainwave abFigure 2. tACS in a clinical trial. normalities. After a Courtesy of Dr. Frohlich. double-blind study on a small patient population with major depressive disorder (MDD), the results suggested that those treated with tACS that targeted the overactive brainwaves in depression had decreased symptom presentation than those treated with placebo or tACS that did not target the overactive brainwaves in depression.6 “It’s a very unusual concept that very weak input – small, low doses of something – can have a big clinical effect,” says Dr. Frohlich. “We use very weak electricity – 1000 times weaker than electroconvulsive shock therapy – to sync in with rhythmic signals.”4 The fact that the electrical stimulation is so weak means that the method is relatively safe for clinical trials – it is not like a new pharmaceutical concoction with potential side effects to vital organs. And the safety and current lack of side effects enables tACS to be an improvement to current psychiatric treatments, if future studies are successful.

Depending on the psychiatric illness, the location, and the type of electric stimulation changes, Dr. Frohlich hopes that tACS can revolutionize psychiatric treatment. Follow-up studies within the Carolina Center for Neurostimulation are examining the effect of tACS on symptoms of schizophrenia and chronic pain – and they all look promising. “The key is stimulation and clinical improvement, but our focus is on the biology in between to focus on the science behind the rhythmic activity pattern that predicts the clinical response,” Dr. Frohlich says. “There’s a fundamental change where we’re really putting a lot of neuroscience into these studies.”4 Dr. Frohlich’s research puts much more than just neuroscience into the clinical trials. His research into tACS also warrants a deep understanding of biological systems, as well as mathematics and physics to obtain correct wave forms. “My approach is really one of synthesis,” says Dr. Frohlich. His research also utilizes the assistance of several clinicians within the UNC Health Care system. “The openness of the clinicians should really be highlighted in this. I think it’s also a bit unique about Carolina. The idea that I can go to a world expert in mood disorders and say, ‘You know I have this crazy idea

psychology and neuroscience

about weak electric currents, do you want to work with me and help with this study?’ It requires a certain climate and a certain openness of the clinical researchers, and that fills me with a lot of gratitude.”4 But his research into the neural network of brains does not stop at tACS. Dr. Frohlich is also interested in other possible modes of therapy, such as music therapy. In doing so, he is currently exploring how the brain activity of a group of musicians synchronizes to form a new network. “Ultimately, everything is back to how networks are configured.”4 For Dr. Frohlich, his goal is to continue studying the effects of tACS in clinical trials to revolutionize psychiatry and heal patients. “It is possible to have a successful career, to mentor the next generation of scientists to be successful in their own right, by pursuing a seemingly crazy and unusual idea and by really seeing it through and bringing all these different expertise and perspectives together.”4

Figure 3. Clinical Symptoms of Depression Following tACS Treatment. Courtesy of Dr. Frohlich.

References

1. Cassan, A,; Kubas, D.; Beaulieu, J.-P.; Dominik, M.; Horne, K.; Greenhill, J.; Wambsganss, J.; Menzies, J.; Williams, A.; Jorgensen, U.G., et al. Nature 2012, 481, 167-169.

2. von Bartheld, C.S.; Bahney, J.; Herculano-Houzel, S. The Journal of Comparative Neurology 2016, 524, 3865-3895.

3. Carolina Center for Neurostimulation, carolinaneurostimulation.org (accessed September 23rd, 2019).

4. Interview with Flavio Frohlich, Ph.D. 09/20/19 5. Leuchter, A.F.; Cook, I.A.; Hunter, A.M.; Cai, C.; Horvath, S. PLoS ONE 2012, 7.

6. Alexander, M.L.; Alagapan, S.; Lugo, C.E.; Mellin, J.M.; Lustenberger, C.; Rubinow, D.R.; Frohlich, F. Translational Psychiatry 2019, 9, 106.

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psychology and neuroscience

The Puzzle with Infinite Pieces

By Maia Sichitiu

Figure 1. Picture Stimulus from 2014 Transfer Verbs Project. Courtesy Dr. Arnold.

H

as there been a major question crawling at the back of your mind? A daunting one that spawns dozens of other inquiries? If so, you’re stumbling onto a fruitful path: the path of research. Although society frames research as an impressive feat of structured work and answers, it is forgotten that the basis of research relies on beginning with a question that builds with years of work and new implications into a flurry of questions, each more intriguing than the last. This hectic and rewarding process is highlighted by one of UNC-Chapel Hill’s own cognitive science researchers, Dr. Jennifer Arnold,

who has recently found an extremely promising direction after grappling with a question that she has been working on since her grad school days.

As to what one of her most recent projects entails, there is an abundance of linguistic and behavioral complexities to search but consider this example: Jane impressed Sarah because she is a good dancer. As a reader, you probably reached the conclusion that the ‘she’ in the sentence refers to Jane.

Verbs like the word impressed and other indicators in our everyday conversations help us make these leaps.

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Dr. Jennifer Arnold For decades, Dr. Arnold has been interested in unearthing the subconscious phenomenon of how speakers make such conclusions based on the context of a conversation. She began to conduct research for her dissertation on several different questions specifically about using and understanding pronouns in context. One chapter of her dissertation narrowed the focus to how transfer verbs, which include words such as ‘gave’ or ‘received,’ created a certain expectation for readers and how they would refer to characters in the scenario in later conversations. In this case, she would pose a sentence such as Jane received

Carolina Scientific

psychology and neuroscience

a text from Sarah and she took a screen- It instead continued to fuel her work as story was aided by visual aids created by shot. As a reader, you can assume that a researcher for years to come as she another student, Hilary Jaap. The team Jane is the ‘she’ because she is the one of strove to reinforce her early findings wove transfer verbs into the story withreceiving the text; from this expectation, and ask even more questions based on out the knowledge of the subject. The you establish Jane as the ‘goal character.’ those findings with new methods. students were asked questions about When subjects were asked to talk about Thirteen years after her initial the story and evidence was gathered Jane and Sarah in Dr. Arnold’s passage work with verbtypes and transfer verbs, from there. In their final paper, strong continuation method, she would record Dr. Arnold began to work on another evidence was found to support their whether they would then use the word project with UNC graduate student Elise thesis. In addition, Dr. Arnold recognized ‘she’ or the name Sarah or Jane to refer Rosa. While studying transfer verbs, Dr. the potential behind their new methodto characters. She took note of a stir- Arnold and Ms. Rosa wanted to explore ology that passage continuation did not ring effect that other researchers were new research techniques. Both reached allow for in her graduate school work; unable to replicate when experiment- the conclusion that the typical method she decided to use her newly formed ing with this same question; subjects that psychologists use is far too manu- method to test the effect that was origiwere likely to use vague pronouns such factured. This old method they were nally shown in her dissertation. as ‘she’ when referring to the goal char- referring to was passage continuation, Now in 2019, Dr. Arnold has an acter [Jane] “We had this instinct that maybe we would be more likely up and comand the name ing paper that to get these effects if we put people in a situation that was shows promisSarah when more like natural conversations” referring to ing evidence to Sarah. Dr. Arnold concluded that this which involves giving the subject a sen- support her thesis that verbtype does, was because subjects had a stronger tence fragment such as “Jane impressed indeed, have a direct effect on how and connection to the goal character and Sarah because….” before asking them when speakers use pronouns. The revwould therefore be likely to assume that to continue the story. This method was elation that people use pronouns more others listening would already know created to allow the readers to rely on when talking about something that is who vague pronouns such as ‘she’ would their own thoughts, which in turn was more predictable based on the meanbe referring to. Dr. Arnold was one of the supposed to mimic natural conversa- ing of the previous sentence is newly first in her field to ask questions about tion. However, Dr. Arnold and Ms. Rosa realized and relatively unexplored. Relanguage in context in such depth, and had a different idea about how this searchers across the field had been unshe was also one of the first to replicate methodology was not applicable in pro- able to come to this conclusion until this effect in her dissertation. Previous noun research — “people who use this now. Dr. Arnold’s new conclusion now researchers had stated that their work method [passage continuation] would raises new questions in cognitive scishowed that speakers do not use pro- just repeat the names they are given,” Dr. ence and linguistics fields. First, why is nouns more when the referent is pre- Arnold explained, going on to say, “We there this effect? The results born from dictable; Dr. Arnold’s work, on the other had this instinct that maybe we would her lengthy but rewarding process now hand, showed a small but noticeable be more likely to get these effects if we have the potential to spawn dozens of effect that established that speakers put people in a situation that was more new projects for people across the field. do use pronouns more when the refer- like natural conversation.”2 With a smile, she said she is thrilled at ent is predictable. This was a fascinating With this in mind, they for- the prospect: “This is a pretty interesting find at a time when work on a speaker’s mulated a fascinating new method. In finding because it’s so new, and there expectations was undefined. She pub- their original approach, they led their is so much more to explore.”2 Keep Dr. lished her findings with her dissertation subjects into a room while setting up a Arnold’s essential process and results in in 2001.1 This question about a speaker’s scenario in which they played the role mind next time you’re finding yourself induced expectations from prior con- of a detective. The story unfolded from dismissing an ambitious question. text did not end with her graduate work. there as they investigated a murder. The

References

1. Arnold, J. E. (2001). The effects of thematic roles on pronoun use and frequency of reference. Discourse Processes, 31(2), 137-162. (Accessed 9/17/19) 2. Interview with Dr. Jennifer Arnold, PhD (9/10/19) 3. Weatherford, K., & Arnold, J. E. (under review). Semantic predictability of implicit causality can affect referential form choice. Ms., University of North Carolina (Accessed 9/17/19)

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Carolina Scientific Executive Board

Sophie Troyer Editor In-Chief

Sidharth Sirdeshmukh Editor In-Chief

Divya Narayanan Copy Editor Asssociate Editor

Andrew Se Managing Editor Treasurer

Alexandra Corbett Design Editor

Aneesh Agarwal Associate Editor

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Carolina Scientific

PAST EDITIONS OF CAROLINA SCIENTIFIC

Check out all of our previous issues at issuu.com/ uncsci. As the organization continues to grow, we would like to thank our Faculty Advisor, Dr. Gidi Shemer, for his continued support and mentorship.

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“The virtues of science are skepticism and independence of thought.”

- Walter Gilbert

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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