The poster session for the eighteenth annual Celebration of Undergraduate Research will be held in the Great Hall of the Frank Porter Graham Student Union. Odd-numbered posters will be in poster session 1 (1:15-2:15); even-numbered posters will be in poster session 2 (2:30-3:30).
Advisor: Claudia Yaghoobi (Asian Studies)
Abstract: In Alia Mamdouh's novel, The Loved Ones, the portrayal of the relationship between mother and son as a source of pain for both parties is revolutionary because it exposes a woman's multifaceted view on a relationship that is often oversimplified by male authors. From the child's perspective, Mamdouh juxtaposes Nader's memories of his mother's overbearing love with his memories of war in his home-country of Iraq. From the mother's perspective, Mamdouh compares Suhaila's physical pain and illness to the emotional pain she felt from her son's abandonment and her loss of identity as a mother. This complicated feminine perspective is critical for an audience of women seeking comfort and community in what is often an isolating part of life. Additionally, in order for men to understand and empathize with the challenges women face they must first be exposed to women's views on their own experiences and identities. Mamdouh's novel disrupts a female narrative that men all too often dominate. This will be portrayed on our poster through direct quotations in the novel, visual imagery, and information from previous articles about women's multifaceted views.
Advisor: Claudia Yaghoobi (Asian Studies)
Abstract: In the aftermath of the Second World War, the Iranian government and sociopolitical sphere were set into turmoil by a 1953 coup d'etat assisted by the United States CIA, which put the authoritarian regime of Reza Shah Pahlavi in power. Reza Shah focused on modernization and Westernization to present a more "advanced" image of Iran to his Western allies, but his policies did little to actually help the impoverished and disenfranchised, and heavily restricted political freedoms. Born in 1935, Forugh Farrokhzad came of age under the rule of Reza Shah, and thus had a firsthand understanding of the social and political climate of the time: as a woman, she particularly was caught in the tug of war between the competing interests of traditionalism, nationalism, and secularization. Through her poetry, she affirmed her own identity and autonomy in the face of the regime's repressive platform. In our research, we analyze her use of eye and mirror imagery as a reclamation of self-sovereignty and the reversal of the male gaze in her poems "Another Birth," "The Gift," "Green Phantasm," and "Earthly Verses". We argue that Farrokhzad uses this kind of imagery to subvert the typical state women are placed into as the object of desire, instead presenting herself as the subject, turning her own gaze onto herself to contemplate alienation and her role as a woman, bringing female sexuality to the public eye, and also onto men, placing them in the position of desired object.
Advisor: Kurt Gray (Psychology and Neuroscience)
Undergraduate Co-Authors: Thomas Savransky
Abstract: People are poor for different reasons. Some reasons are unfair circumstances, such as severe illness and mass unemployment, whereas other reasons seem more like personal failings, such as laziness and addiction. Previous research shows that individuals who express prejudice against poor people attribute poverty more to personal failings and less to unfair circumstances. However, recent research shows that people imagine both poor people and "welfare recipients" as African-American, regardless of their reported attitudes toward poor people. Thus, when people report their attitudes toward poor people, these attitudes might actually be about poor Black people. We tested whether reported attitudes about "poor people" reflect attitudes about poor Black people. In study 1 (N = 100), we asked participants to make poverty attributions for photographs of ostensibly poor Black and White people, then indicate their attitudes about poor people. We found that attitudes about poor people only predicted poverty attributions for Black targets. This finding had two consequences: one, those who reported higher prejudice against poor people made harsher poverty attributions for poor Black targets. Two, those who reported lower prejudice against poor people made harsher poverty attributions for poor White targets. This study supported our predictions and showed that those who endorsed non-prejudiced beliefs about poor people actually show harsher judgments of poor White people.
Advisor: Claudia Yaghoobi (Asian Studies)
Abstract: Middle Eastern women's writing in the context of intersectionality will be addressed through the analysis of Sahar Khalifeh's novel, The Inheritance. The novel investigates the struggle to discover and define identity within the confines of two radically different cultural spheres. The story of the protagonist, Zeynab, explores the adversity of double "othering" within her cultural backgrounds - Palestine and America - as a woman. The American perception of Palestine has been tainted by the lenses of Orientalism. The values of her Palestinian cultural background conflict with this new American culture in which she has been immersed. This causes the protagonist to struggle with understanding who she is supposed to be within these societies, with particular regard to the responsibility of carrying her Palestinian cultural traditions. Beyond the matter of cultural conflict, she must also navigate these cultures adversities as a woman, presenting a third-layer of estrangement. The poster focuses on issues of feminism, the position of the individual in diverse societies, navigating the obstacles that come with the predisposition of a mixed identity, and attempting to define an independent identity while faced with factors of cultural assimilation and historical agents.
Advisor: Rebecca Kreitzer (Public Policy)
Undergraduate Co-Authors: Kathryn Townsend
Abstract: Undocumented immigration has been a major modern political debate, yet there have been few immigration policies achieved since the Immigration Reform and Control Act of 1986. One of the few progressive policies passed, the U Visa, was established in 2000. The U Visa allows undocumented victims of certain violent crimes, one of which is domestic violence, a pathway to legal residence, and even citizenship, with certification that the survivor has cooperated with law enforcement. This research seeks to determine the degree to which the U Visa has had an impact on Latina victims' decision to report their domestic violence victimization to law enforcement, and for whom the effect was relevant. I have found that, with the establishment of the U Visa in 2000, there was only a statistically significant increase when controlling for the relationship with the abuser and, with the implementation in 2008, there was actually a statistically significant decrease in the likelihood that a Latina survivor would report victimization from domestic violence to law enforcement. This provides evidence to signify that the U Visa has been ambiguously unsuccessful in encouraging Latina survivors to involve law enforcement, although it can be improved with policy changes including, but not limited to, specific, fair, and transparent guidelines for who will receive the U Visa that remove some disproportional power from law enforcement and a higher cap on the U Visa applications.
Advisor: John Bruno (Biology)
Abstract: Course-based undergraduate research experiences (CUREs) engage students in hypothesis driven research early in their college careers. Due to their classroom context and few barriers to enrollment and participation, CUREs are often cited as a way to involve more students in research earlier in their college careers. At the University of North Carolina, approximately half of the undergraduates majoring in biology have the opportunity to conduct research during their college career, and the majority of these students must actively seek these experiences. In an effort to involve more students in research, engage students who might not normally seek research opportunities, and enrich the academic experience of biology majors, we developed and implemented a CURE called "Seafood Forensics." We used a mixed methods approach to evaluate the efficacy of the first implementation of this CURE in order to inform future iterations of course design. For the quantitative component of our study, we used instruments previously validated for undergraduate populations to assess 1) outcomes known to result from participation in research that are related to academic success and persistence in science, and 2) course design as experienced by the students. To collect qualitative data, we a) conducted two focus groups post-class participation and B) asked students to respond to six open-ended questions at the end of the class. We report results that characterize students' experience and outcomes.
Advisor: Kelly Ryoo (School of Education)
Abstract: Interactive visualization technologies, such as simulations, can automatically collect massive data on how students interact with tools while learning science. Grouping and comparing such data can identify students' interaction patterns which can be used to create more personalized learning environments. Existing methods for analyzing and comparing interaction data are often inflexible and hard to incorporate in newly developed visualizations. The purpose of this study is to explore the effects of a new computational method that uses numerical encoding and Levenshtein edit distance, developed to be simple and flexible for encoding and comparing student interaction data. The study involved linguistically diverse 8th-grade students from a low-income middle school. Students engaged in predict-observe-reflect activities using interactive simulations to explore chemistry concepts. All students' interactions with the simulations were automatically logged, including the order of various button clicks. Reflection questions were scored based on a rubric evaluating content, claim, and evidence provided by the student. Students were grouped based on reflection score and, upon processing the interaction data with the proposed method, statistically significant differences were found between mean edit distances of each score group. The results suggest that this new method shows promise for comparing interaction data as differences in learning patterns were found between the score groups.
Advisor: Elliott Moreton (Linguistics)
Abstract: To make a noun plural, one writes a "s" at the end, but the pronunciation of "s" actually depends on the word -- Sometimes it's buzzy like "z" as in "dogs". This is determined by the sound-patterns that English-speakers acquire. These patterns target sounds that are grouped by common properties and features. The pronunciation "s" depends on whether the final sound of a word has vibrating vocal cords. Prior studies find that language-learners show biases towards acquiring certain patterns in second languages. This study proposes feature activeness to be one source of linguistic bias. Active features are those used in a large number of sound-patterns. This study consists of a corpus study testing for within-language activeness biases, and an online artificial language-learning task where 100 subjects learn sound patterns using features of various activeness in the English language. This second task assesses whether activeness biases apply in second-language learning. The experiment will be completed in early-mid March. In the corpus study, frequency distributions generated by a rich-get-richer algorithm were fitted to the data and tested for equivalence with the observed feature distribution for five unrelated languages. Results suggest within-language feature frequency distributions for each of these languages exhibit rich-get-richer effects, and that languages prefer to reimplement active features. This offers a new perspective on the mental organization of language.
Advisor: JingJing Li (Chemical Biology and Medicinal Chemistry)
Abstract: The American Cancer Society reports that this year there will be an estimated 600,920 deaths due to cancer in the United States. Current cancer research includes the use of biomarkers on the surface of cancer cells to distinguish the cancerous cells from normal body cells. Molecular cloning can enhance these biomarkers. Over the past thirty years, molecular cloning has progressed immensely. From digestion to plasmid insertion, the possibilities are endless. The AAV (Adeno Associated Virus) CXCL12(C-X-C Motif Chemokine Ligand 12) is a Protein Coding gene that shows great promise with cloning and plasmid insertion. Our project aims to use this gene to bind tightly to biomarkers on the surface of cancer cells. However before this optimal binding can occur, it is essential to know more about the AAV CXCL12 Gene itself. For this reason, our project includes multiple gel electrophoresis assays, plasmid insertion/digestion assays, and PCR purification. From the results of these assays, the efficacy of AAV CXCL12 to bind to cancer biomarkers will become clear. In particular, the cloning assay for the AAV CXCL12 gene holds great potential, as it is possible to clone extraneous DNA into a different host. If extraneous DNA can be cloned into a different host, then there is the possibility of that DNA binding to a biomarker on a cancer cell.
Advisor: Michele T. Berger (Women and Gender Studies)
Undergraduate Co-Authors: Sue Leichliter
Graduate Student Contributors: Katherine McKibbon
Faculty/Postdoc Contributors: Moriah Glenn
Abstract: This project is a continuation of a Bass Connections project that brings together Duke and University of North Carolina-Chapel Hill faculty and students, Communities in Schools of Orange County, the Chapel Hill/Carrboro Public Schools and Y.O.G.A. for Youth NC for a multiyear quantitative and qualitative research study. We are analyzing the effects of a regular yoga and meditation practice on middle school students' mindfulness, emotional regulation, self-esteem, stress response, resilience, physical health, academic performance, and social behavior. In 2016-2017, we continue working on building our research successes by focusing on developing original scales and instruments to support the empirical study of yoga and mindfulness in schools. We also host a day long conference every year called the Embodied Learning Summit. This event brings community members, students, yoga teachers and practitioners, and all interested to discuss the intersections of yoga and social justice.
Advisor: Joaquin Drut (Physics and Astronomy)
Abstract: We investigate two numerical techniques applicability towards quantum many-body problems. Specifically we explore there usefulness for those problems which suffer from the numerical sign problem. Initially a Numerical Recursive Integration Technique was tested following the 2016 paper by Ammon, Genz, and Hartung. The method was tested against the 1-D topological oscillator for which it performed well, however the method gets considerably more complex and cumbersome for higher dimensional problems lacking in symmetry. As such, it was determined to be ill-suited for tackling the sign problem in many body physics. Next the much more promising Complex Langevin Method was investigated. Many other studies have shown the method is quite effective at tackling the sign problem inherent in many body problems. To see for ourselves it was tested on a repulsive 2-D Hubbard Model. As of now the code/tests are still running. As the research moves forward we hope to be able to use this method to model high Tc superconductivity in the 2-D Hubbard model as well.
Advisor: Ryan Shaw (School of Information and Library Science)
Abstract: In today's "information age," across the globe digital technologies are transforming people's everyday lives. These advances have depended on computer science, so it becomes important to ask who will be the next generation of computer scientists: who gets early access and a head start into CS, and who lacks such access. High school CS education plays an important role. In this study, I examined various literatures on how the U.S. and China responded to the opportunities and challenges of bringing CS to high school students. I took a cultural studies approach: cultural studies' concept of articulation-the artificial association of distinct notions, provided a framework for analysis. By looking at how CS is articulated with distinct notions such as race, gender, power, and citizenship, I analyzed the reasoning and struggles behind the classroom scenes. I traced through a brief history of K-12 CS education in both countries, and analyzed how various education practitioners (industry, academia, government, nonprofit) approached high school CS education with slightly different roles and motivations. The comparison between countries showed that although currently CS education resources are distributed unevenly, education practitioners in both countries think that CS should be for everyone: it is no longer enough to simply teach students how to use software, but students should be creators of software and drive future innovations.
Advisor: Peter Gordon (Psychology & Neuroscience)
Abstract: The ability to use more than one language and the impact it may have on the brain has raised questions about how monolinguals differ from each other. Patterns of priming provide a way to assess the similarity of representations for language in the minds of monolingual and multilingual individuals and to determine the overlap of the lexicons for different languages in the minds of multilingual individuals. Researchers who have used priming to understand the connectivity of two languages in a bilingual have found that repetition priming is equivalent to cognate priming. Cognates are words that are identical semantically and similar phonologically and orthographically. The focus of this study is to determine the basis of repetition and cognate priming with the goals of determining if the two types of priming really have the same magnitude in addition to understanding how cognate pairs are processed and represented in the bilingual brain in comparison to repetition pairs. This research will contribute to understanding the structuring of the lexicons of a bilinguals two languages. Key Words: Priming, Cognate Pairs, Repetition Pairs, Lexicons
Advisor: Peter Ornstein (Psychology & Neuroscience)
Abstract: The purpose of the present study was to examine teachers' use of cognitive processing language (CPL) as they teach language arts and mathematics. Instruction that is rich in CPL encourages the deep processing of material and metacognitive awareness and has been shown to facilitate first-grade students' strategy use in memory and math. More specifically, the question of whether teachers can be trained to increase their use of CPL during math instruction via a mid-year training session was explored. A total of 14 teachers and 87 students were recruited to participate in this study: eight teachers were assigned to the "experimental" condition (receiving the mid-year training) and six teachers were assigned to the "control" condition (delayed, end-of-year training). Previous findings from this area of research were replicated, showing that teachers vary naturally in the extent to which they incorporate CPL during math instruction. Furthermore, initial evidence was found to suggest that the use of CPL is malleable, such that teachers can be trained to use greater amounts of specific features of CPL. We are currently in the process of analyzing child-level outcomes to examine whether students whose teachers were (a) naturally high in their usage of CPL, or (b) showed increases in CPL after the mid-year training were more adept at using strategies to solve math problems and/or remember new information at the end of the first grade year than were their peers in low-CPL classrooms.
Advisor: Richard Faldowski (Allied Health Sciences )
Abstract: to be completed later
Advisor: Gary Glish (Chemistry)
Faculty/Postdoc Contributors: Gary Glish
Abstract: Aerosolized compounds are of interest to many industries, particularly those centered around cigarettes and e-cigarettes. Aerosols may contain compounds with adverse health effects, so there is a need for an efficient and accurate means of aerosol analysis. Extractive electrospray ionization mass spectrometry (EESI-MS) is one method that can be used for sampling of aerosols in real-time. EESI involves electrospraying through a nebulized sample to extract the compounds into electrospray solvent. Coaxial EESI is a variation of EESI developed in our lab that can be used for aerosol analysis and improves upon many aspects of EESI. A Thermo Scientific Ion Max electrospray ionization (ESI) source was investigated as a potential means of performing coaxial EESI. This commercial design has concentric capillaries for optimization of gas flow, but has not been previously used for aerosol analysis. The Thermo ESI source was tested for EESI using an aerosolized standard of levoglucosan on a linear trap quadrupole and Fourier transform mass spectrometer. In this case, the electrospray solvent was spiked with 5 mM lithium acetate. The mass spectrum obtained revealed the presence of a lithiated levoglucosan peak characteristic of EESI. This confirmed using Thermo ESI as a viable means of performing coaxial EESI. Further experiments have shown that for a pyrolyzed sample of cellulose, a characteristic mass spectrum can be obtained from coaxial EESI using a Thermo ESI source.
Advisor: Dan Reichart (Physics & Astronomy)
Undergraduate Co-Authors: John Martin, Logan Barnes
Abstract: Collecting data and taking measurements has always been the most fundamental concept in science. Unfortunately, this data can often become contaminated and radio astronomy is of no exception to these contaminations. A combination of exceedingly sensitive detectors on modern radio telescopes and crowding of the radio spectrum due to the use of everyday devices (cell phones, Wi-Fi, etc.) has caused contamination of astronomical data to become a serious concern. The scope of this project aims to reduce these contaminants to sub-noise levels by using a combination of local modeling and a rigorous outlier-rejection algorithm. These common contaminants can be separated into three categories: En-route signal drift, radio-frequency interference (RFI), and elevation-dependent signal. Preliminary simulation-based testing shows that the algorithm is effective at removing large-scale structures. For example, en-route drift and long-duration RFI are reduced by factors of ~61 and ~590, to ~5% and ~36% of the noise level when using a 6-beamwidth scale, respectively. Large-scale astronomical and elevation-dependent signals are reduced by factors of ~510 and ~710 to ~9% and ~5% of the noise level, respectively, when using a 6-beamwidth scale.
Advisor: David Plaisted (Computer Science)
Abstract: Many automated theorem proving applications rely on the DPLL algorithm for deciding the satisfiability of a set of propositional logic formulae. This algorithm exhaustively enumerates ground clauses within the Herbrand universe below an incrementing size-bound. From even a cursory investigation of these enumerated clauses, it is evident that many of them have multiple repeated terms. Here, we explore a potential method for exploiting the size-bound by "cheating in'' larger clauses with many repeating terms that may be relevant to the proof.
Advisor: Scott Warren (Applied Physical Sciences)
Abstract: host material's carrier concentration and optical properties. While these optical properties have been previously modeled for potassium-intercalated graphite (KC8), a reliable model for the optical behavior of few-layer KC8 remains relatively unexplored. We apply the Drude model to predict the transmission and reflection of few-layer graphene KC8 over the visible and near infrared wavelengths, and compare our simulated reflection and transmission spectra to experimental data of few-layer KC8. With these results we address the validity of the Drude model in both the visible and near infrared spectra. The generalizability of the Drude model may provide a route to improving simulated optical properties of electron-donating intercalants in few-layer graphite structures.
Advisor: Priscilla Layne (German and Slavic Languages and Literatures)
Abstract: Keywords: identity, place, history, culture, background, Germany, creative writing, illustration I grew up hearing stories about Steegerhof, the house in which my grandparents lived in their native Germany, and the home in which my father had spent some of his childhood. It has been in my family for four generations, and I knew it was not only surrounded by stories and superstitions and full of historical artifacts from around the world, but also the reason why, in several cases, members of my family settled where they did. I began wondering: how did the house affect the history of my family, and how did my family change the history of the house? What could I learn about my family and the history of that region of land from studying the house? How could this information serve as a model, or inspiration, for others who want to learn more about their families and themselves by studying a place? To answer these questions, I spent the summer living in the house and recording my own experience in it, interviewed family members and family friends, looked at primary source documents such as letters and notebooks, and conducted historical and cultural research to supplement what I found. Throughout four generations, Steegerhof has shaped the lives of the individuals who spent time there in many ways, and each individual left their mark on the house in return. Steegerhof shares history with, and has influenced, the community around it. The art book I produced, The Waiting and Weepin
Advisor: Jason Metcalfe (Mathematics)
Abstract: Wave equations model a wide variety of phenomena in diverse fields such as optics, geology, and cosmology. Therefore, it is of interest to determine which wave equations have solutions defined for all time given small initial data, and which exhibit blow-up of solutions in finite time for arbitrarily small initial data. In this project, a coupled system of semilinear wave equations is considered, and a small data global existence result related to the Strauss conjecture is proved. Previous results have shown that one of the powers may be reduced below the critical power for the Strauss conjecture provided the other power sufficiently exceeds such. The stability of such results under asymptotically flat perturbations of the space-time where an integrated local energy decay estimate is available is established.
Advisor: Gregory Flaxman (English and Comparative Literature )
Abstract: The presentation will contain material from my English Seniors Honors Thesis. In my research I went back to one of the most influential philosophers for modernity, Friedrich Nietzsche. I investigated what themes drove the core of his work. Because Nietzsche was a scholar of Ancient Greece, not only did he possess an enduring admiration for their culture, but their way of everyday life. He looked to the Greek god, Dionysus as the starting point for many of his most significant questions. Marcel Detienne, in his work Dionysus at Large, explores the being of Dionysus. I used this work to shed light on the labyrinth of Nietzsche's mind, and in the attempt to reveal more in Nietzsche's own work. I found that Nietzsche went from a radical change in his philosophy. In the Birth of Tragedy, Nietzsche had the view that Dionysus was a force in Greek culture meant to be constrained by the form and control of Apollo. In his later works, he sees the chaos of the Dionysiac as something grounding the nature of life: a nature of chaos, multiplicity, and eternal change. This made Nietzsche more sympathetic to science in his later works, radically shifting his views on the world, and its direction into the 20th century. For Nietzsche, Dionysus is all and nothing. He represents pleasure and appearance, as well as madness and strangeness. The great paradox of Dionysus is that he can reveal much about ourselves, while also revealing little. Dionysus has no identity, save that he was born fr
Advisor: Karl Castillo (Department of Marine Science)
Abstract: Coral reefs are increasingly threatened by anthropogenic climate change stressors such as rising seawater temperature, ocean acidification, nutrient enrichment, sedimentation, and overfishing. These stressors have led to significant declines in the health of coral reef communities around the world, particularly those in the Caribbean Sea. These anthropogenic impacts have caused shifts in reef communities from coral-dominated communities to algal-dominated communities. As coral community health, cover, and diversity decrease, so does architectural complexity. It is important to study the 3D structural complexity of reef-building corals since certain, more complex, coral communities offer niche habitats for many aquatic species and contribute greatly to the biodiversity of marine ecosystems. In the past, reef complexity has been studied by techniques that rely heavily on estimation with survey divers rating complexity on a scale of 1 to 5. These methods, however, are somewhat subjective and semi-quantitative and can vary based on the individual conducting the survey. New imaging methods now allow for 3-dimensional reconstructions to produce metrics that are far more accurate than previous, more subjective estimations. In this project, we seek a reliable method for producing these reconstructions from diver survey videos using Agisoft PhotoScan.
Advisor: Carl Mummert (Mathematics)
Abstract: We study the number of mates of latin squares which are powers of cyclic squares. For k > 1 the cyclic square C_k is the Cayley table of Z_k. The power square (C_k)^n is obtained by taking a repeated Kronecker product of C_k with itself. In this work, we consider the power squares (C_k)^n for k > 2 and n > 1. For each of these squares, we enumerate a family of mates of a particular form. This gives an asymptotic lower bound for the number of mates that a latin square can have in terms of its size.
Advisor: Joel Hudley (Geological Sciences)
Abstract: Bivalve shells contain a record of their ontogeny (growth history), in the form of internal growth lines observed microscopically in sectioned shells (analogous to tree-rings). The analysis of these repeating shell structures (sclerochronology) has been shown to have considerable potential for recording environmental changes, (e.g. seasonal seawater temperature changes, storms, and disturbance) as well as anthropogenic perturbations (e.g. trawling activities). Recent temperature variations in the western Atlantic have impacted the biogeographic ranges of benthic, infaunal organisms and evidence of this thermal shift is likely encoded in the shells of long-lived organisms. The bivalves Arctica islandica, the ocean quahog, and Hemimactra (Spisula) solidissima, the Atlantic surf clam, are long-lived species often reaching ages of 20-200 years. Surveys conducted by the National Ocean and Atmospheric Administration Northeast Fisheries Science Center (NOAA-NEFSC) obtained live samples from across the Middle Atlantic Bight (MAB) during the summers of 1994 and 1997 and previous aging and growth studies have revealed maximum ages of 203 y for A. islandica and 26 y for S. solidissima. This work focuses on achieving cross-matching growth records from across the MAB for both archetypical bivalve proxies. By producing and then comparing these two separate bivalve chronologies, we may be able determine what local and regional environmental variabilities influence the species' shell inc
Advisor: John Bruno (Biology)
Abstract: The deliberate mislabeling of seafood products has been documented on a global scale, but with little data and few papers on the subject, trends and rates in seafood fraud have not been recognized. The goal of this paper is to estimate the rate of seafood mislabeling. This is a growing issue in the global seafood industry as fish consumption per capita increases significantly and fish stocks continue to decline with overfishing1, 7. Seafood distributors aim to maximize their profits by passing off less desirable seafood as more in-demand species, harming consumer's health and our marine environment alike2, 4. By conducting a systematic literature review and compiling data on seafood mislabeling from global studies, I found that 24.23% of 4,709 seafood samples were mislabeled. Our results indicate that Catfish and Snapper are the most commonly mislabeled seafood, and that cooked samples are more likely to be fraudulent than fresh or frozen samples. Rates of mislabeling by continent vary widely with South America having the highest rate of seafood fraud and Europe having the lowest rate. The United States was found to have a rate of mislabeling of 35%, with the Northeast region of the country having the highest prevalence of mislabeling. More data needs to be collected on mislabeling by type of product and by type of vendor to determine an accurate trend in seafood fraud, as well as how seafood labels such as"wild-caught" and "sustainable" affect mislabeling rates.
Advisor: Jason West (Department of Environmental Sciences and Engineering )
Abstract: Ozone is one of the most dangerous greenhouse gases and is prominent throughout the troposphere. Emissions of chemical species that can lead to the formation of ozone have been lessening in developed nations and growing in developing nations. Using the global chemical transport model CAM-chem changes in ozone concertation in the troposphere were analyzed in relation to different factors and variables. Specifically, the tropospheric ozone load was projected from 2010-2040 and emissions in different regions were manipulated in order to see the global effect. It is important to make the distinction between regional increases in anthropogenic ozone emissions and simple increases in magnitude. It is predicted that increases in ozone emissions in certain regions will have a greater impact on the total global ozone load. Specifically the results of previous studies which determined a greater significance to South and East Asian emissions shall be replicated with the projection into the next thirty years
Advisor: Gary Pielak (Chemistry)
Faculty/Postdoc Contributors: Gary J. Pielak
Abstract: The cellular interior is a complex environment where the concentration of macromolecules exceeds 300 g/L. Under these crowded conditions, proteins experience hard-core repulsions and chemical interactions with cytoplasmic components that are not present in buffered alone. Hard core repulsions arise from steric repulsions and stabilize to proteins. Chemical interactions can be stabilizing if repulsive and destabilizing if attractive. Studies of these interactions have broadened our understanding of protein chemistry in cells, but most use simple monomeric proteins. However, proteins rarely work alone, and protein-protein interactions give rise to complex protein architectures. A variant (T2Q/L5V/F30V/Y33F/A34F) of the B1 domain of protein G forms a domain swapped homodimer. I labeled the sole tryptophan of the domain with fluorine labeling and used 19F nuclear magnetic resonance (NMR) to quantify the effect of cosolutes on the dimer dissociation constant. Macromolecular cosolutes stabilize the dimer, suggesting the importance of hard-core repulsions. Experiments with some of the monomers indicate that chemical interactions are destabilizing. The effects of biologically relevant protein crowders show that they work through an intricate mix of hard-core repulsions and chemical interactions.
Advisor: Laura Moore (Geological Sciences)
Abstract: Coastal dune height can have important effects on beachfront properties by defending homes from storms, and limiting or allowing for valuable ocean views. Low dunes do not obstruct views but offer poor storm protection, while high dunes can block views but provide greater storm protection. My project explores if and how the value of beachfront property is influenced by dune height, and what trade-offs, if any, exist between view and storm protection. I analyzed dune height and sale prices of beachfront homes sold through 2013-2014 in the following Coastal North Carolina Counties: Carteret, Dare, Brunswick, and New Hanover. I used a comprehensive list of property sales records acquired from Dr. Sathya Gopalakrishnan from Ohio State University to select first-row, beachfront homes not within 1 km of an Inlet (n=271). I used cross sections of elevations from a LiDAR model to assess the dune height in front of each beachfront house. Using this data, I analyzed the relationship between home price and dune height. This study will produce important information about the relationship of dunes and the prices of beachfront homes. These findings are important to coastal community governments, economists, real-estate agencies, and buyers and sellers of oceanfront homes.
Advisor: Jonathan Engel (Physics)
Abstract: In this project, we calculate the contribution of the three-body effects on the neutrinoless double beta decay transition matrix element between the ground states of 76Ge and 76Se within a 2-shell model space under the influence of a model Hamiltonian constructed from the isospin generators of SO(5) x SO(5) (one set of generators for each shell). The contribution is calculated via the construction of an effective operator acting in a single shell that reproduces exactly some relevant matrix elements of the full two-shell operator; once the effective operator is constructed, the desired matrix element is calculated for the effective operator between the projections of the ground states onto a single shell. While the constructed Hamiltonian is not particularly realistic, it is of the form necessary to admit analytically tractable solutions, and solutions in this model still provide insight into the problem of calculating this matrix element in general. Dr. Jonathan Engel has previously worked out the contribution of two-body effects within this same schema, and this project seeks to extend these results and ascertain the comparative significance of three-body effects, as similar calculations in the simpler SU(2) x SU(2) construction of the problem have found that three-body effects in that schema were non-negligible compared to the two-body contribution.
Advisor: Karl Castillo (Marine Sciences)
Undergraduate Co-Authors: Alyssa Knowlton
Faculty/Postdoc Contributors: Colleeen Bove, Justin Ries
Abstract: Corals and the dinoflagellate algae Symbiodinium exist in an obligate symbiosis where photosynthetically derived nutrients translocated to the host from intracellular Symbiodinium can provide up to 100% of the coral's energy budget. Increases in sea surface temperature and decreases in oceanic pH reduce the competency of corals to maintain this symbiosis. As a result, increased coral bleaching events have been observed globally as climate change progresses. To quantify the immediate, transitional, and long-term physiological responses of coral hosts and algal symbionts to climate change stressors, we exposed the Caribbean corals Siderastrea siderea and Pseudodiploria strigosa to various temperature (28, 31 C) and pCO2 (280, 400, 700, and 2800 ppm) treatments for 90 days. Temperature and pCO2 were fully crossed and four fragments of each colony were maintained in each treatment. One colony fragment was removed at each time point (0, 30, 60, 90 days) and coral tissue protein and chlorophyll a concentrations were quantified as proxies for coral host and algal symbiont physiology. Preliminary results suggest that both host and symbiont physiology are negatively affected by temperature, however both partners appear resilient to changes in pCO2. The results from this study shed light on how pCO2 and temperature stress interact to affect the physiology of coral holobionts.
Advisor: Jim Cahoon (Chemistry)
Abstract: Improving the efficiency of solar cells is vital for easing and accelerating the transition from coal sources to sustainable energy. Here, we investigate using a high surface area, hierarchical ordered photocathode structure in dye sensitized solar cells (DSSCs). We propose that appropriately sized multilayered ordered structures will simultaneously increase overall transmittance and surface area, thus increasing the short circuit current (Jsc). Preliminary results utilize a polystyrene bead self-assembly template to form inverse opal films. Initial optical properties show increased transmittance with a strong green reflection which has translated to small improvements in Jsc and curvature changes in the incident photon to current efficiency spectra in lead titanate photocathode devices.
Advisor: Karl Castillo (Marine Sciences)
Undergraduate Co-Authors: Kinsey Fisher
Faculty/Postdoc Contributors: Karl Castillo
Abstract: Global climate change poses a significant threat to coral reef communities across the greater Caribbean Sea. Previous studies suggest that inshore corals are less impacted by ocean warming than offshore counterparts due to their history of exposure to highly variable environmental conditions. By examining the slow-growing calcium carbonate skeletons of long-lived corals, we are able to quantify how calcification rates have changed in response to decades of differing environmental conditions. ??We extracted cores from Siderastrea siderea (n=39) and Pseudodiploria strigosa (n=22), two abundant and widespread massive Caribbean reef-building corals, to investigate coral growth rates. In 2015, cores of each species were collected from inshore and offshore reef sites within the Bocas del Toro Archipelago, Panama. Using 3-dimensional computerized tomography, skeletal growth parameters were quantified by delineating high- and low-density annual growth bands. This investigation will allow us to compare multi-decadal scale inshore-offshore coral growth trajectories in to better understand growth differences for corals across a reef system as they respond to climate change.
Advisor: Carol Arnosti (Marine Science)
Abstract: Polysaccharides are major constituents of marine organic matter, fueling considerable heterotrophic production. Investigating the dynamics of carbohydrates in marine systems is difficult, however, because carbohydrates lack chemical characteristics that would allow them to be readily quantified or extracted. New advances in imaging techniques offer the opportunity to design novel probes which can be used to investigate the bioavailability of carbohydrates to microbial communities. We focused on the synthesis and characterization of alternative molecules for use in measuring the carbohydrate processing in marine systems. Our objectives were to label the disaccharide sucrose with an established fluorophore which fluoresces in the 530nm range and to test the efficacy of a new fluorophore that fluoresces in the 615nm range. Using a carbodiimide coupling reaction, the activated sucrose was reacted with the primary amine on the fluorescent tag to form a stable covalent linkage and NMR was used to characterize the reaction products. Texas Red cadaverine was chosen because it has minimal functional groups that could facilitate unwanted side reactions. Similarly to fluoresceinamine, its primary amine was used to form a stable covalent linkage to chondroitin-6-sulfate. This fluorphore's utility was also tested with laminarin. Unreacted tag was separated from the labeled polysaccharide and a stability test was carried out to measure shelf life of the labeled product.
Advisor: Brian Hogan (Department of Chemistry)
Abstract: Surface level water supplies in the Bocas del Toro region of Panama showed significantly higher fecal bacteria contamination than rain catchment or filtered systems, and common community surface level water supplies were utilized by households for cooking, cleaning, and bathing, in addition to drinking. The potential long-term effects of exposure to such contaminants, as well as the risk for novel pathogen exposure in such communities through these water sources, requires further investigation. Other environmental metrics showed varying amounts of human impact. Trash and non-degradable human waste accumulated more acutely within mangrove systems located near villages than isolated environments, although this was not the only factor correlated to the mangrove trees' health. Within a section of the archipelago, the sites along popular motorized boat travel paths possessed lower coral reef diversity and higher bleaching incidents, but preliminary sampling also indicates the potential for more generalized coral reef degradation throughout the region. Further analysis of the link between direct human activity and specific environmentals is necessary to understand the mechanism of environmental degradation and its specific risks on local communities.
Advisor: Tyson Hedrick (Biology)
Abstract: We developed a rotatable device for 3D videography and used it to film intraspecific territorial chases between eastern pondhawk dragonflies (Erythemis simplicicollis) in the field. We examined the dynamics of these chases and found that E. simplicicollis often uses similar strategies in intraspecific territorial pursuits as in prey pursuits, and additionally displays longer latencies during intraspecific chases than during prey chases.
Advisor: Scott Gifford (Marine Sciences)
Abstract: The ocean is an ever changing chemical environment with multiple functions, one of which being the storage of dissolved carbon. Much of this carbon is taken up by a diverse set of marine microbial life, so determining how it's cycled through bacteria is key in determining what happens to atmospheric carbon when it enters the ocean, and how changes in bacterial populations will affect ocean chemistry. My research focuses on determining which organic molecules are being used by Ruegeria pomeroyi (strain DSS-3), a member of the Roseobacter clade that can make up 10-20% of all oceanic bacteria. My goal was to identify which R. pomeoyi genes are involved in organic matter cycling. To do this I analyzed the genome of DSS-3 for genes annotated as carbon transporters. I found that DSS-3 contains an ABC transporter that has all the protein subunits necessary for making a complete transporter of glycerol. Based on this bioinformatic evidence, I hypothesized that DSS-3 is able to utilize glycerol as a carbon source. I devised one experiment involving DSS-3 growth in various concentrations of glycerol in both rich media (?? YTSS) and minimal media (marine basal media), and one involving growing R. pomeoyi plates with and without glycerol to compare growth. In both instances, it was proven that DSS-3 grows the best in the presence of glycerol as their source of carbon. The results further define the carbon niche of an important ocean bacterium and their impact on ocean biogeochemistry.
Advisor: Allen Glazner (Geological Sciences)
Undergraduate Co-Authors: Katherine Kelker, Elizabeth Brogden
Abstract: The Bishop Tuff is a Pleistocene ignimbrite whose outflow sheet covers ~1300 km2 in eastern California, extending from Mono Lake on the northern end to Bishop on the southern end. Owens River Gorge (ORG) runs through the tuff, providing well-exposed cross sections that allow the study of columnar jointing. Whereas the phenomenon has been extensively studied in basalts, it is almost undescribed in rhyolite. Our study aimed to gain a greater understanding of rhyolitic columnar jointing and its relationship to fumarolic mounds that surround the gorge, by forming a geologic model based on aerial drone photography, satellite imagery, and scanning electron microscopy in the area south of LADWP Powerhouse No. 1. Columnar jointing in ORG appears to be a modification of the standard three-zone model of basaltic jointing, with a lower colonnade, smaller entablature, and upper colonnade. Above the entablature is a section of thin, shorter joints that commonly radiate from a single point in a manner resembling saguaro cacti. Putnam (1960) proposed that these radiating joints occur below fumarolic mounds and record heat flow away from fumarolic pipes, but in our drone survey we found only a weak correlation. Pumice samples taken from the mounds exhibit secondary mineralization in the form of grape-like clusters of ~200μm spheres, with a tridymite shell enclosing altered volcanic glass. These spheres likely cemented the fragile volcanic ash to form a more coherent, erosion-resistant rock.
Advisor: Frank Tsui (Physics)
Abstract: Our collaborators have been able to make periodically-arranged organic molecules of around 100 nanometers in length. We term these assemblages "polymer brushes" and note their potential applications in electronics. Specifically, these brushes can preserve conduction electron spins, which may be used to convey information in next generation circuitry. To assess the usefulness of these materials, we intend to measure their responsiveness to applied ramping voltages from a Wavetek 30 MHz Sweep Generator. In order to collect these measurements on a computer, we need to interface with the function generator and a Tektronix TDS 3012 oscilloscope via a USB-6002 NI-DAQ board. We then need to acquire the waveforms from the oscilloscope for further analysis. The software to manage the data acquisition is written in LabVIEW, and we present the functionality of that code.
Advisor: Carol Arnosti (Department of Marine Sciences)
Faculty/Postdoc Contributors: Carol Arnosti
Abstract: Marine microbes secrete enzymes to initiate the degradation of organic matter, but the extent to which compositional differences of bacterial communities correspond with differences in enzymatic potential are poorly understood. The manner in which these relationships vary along salinity gradients and with particle association is understudied, despite important implications for river-to-ocean transfer of organic carbon. We build on a previous study that investigated microbial enzymatic activities (EEA) across different salinities and organic matter sources between the South Atlantic Bight and Mid-Atlantic Bight: at the mouth of Chesapeake Bay (CBM), Cape Lookout Nearshore (CLN), and Cape Hatteras Offshore (CHO). To investigate the relationship between bacterial community composition (BCC) and enzymatic potential, we coupled 16S rRNA gene sequencing analyses with previously measured EEA. Our results demonstrate that salinity differences underlie patterns of dissimilarity in both bulk and particle-associated communities at all sites, and these patterns parallel substantial variations in EEA at CBM (freshwater-influenced) versus CLN and CHO (marine), in bulk seawater as well as on particles. Additionally, taxonomic analyses reveal the enrichment of specific taxa on particles; these taxa differ at CBM versus CLN and CHO. Congruence in BCC differences and EEA suggest a link between structure and function???a relationship evident along salinity gradients and with particle-association.
Advisor: Tony Rodriguez (Marine Sciences)
Abstract: The TAZ, or Taphonomically Active Zone, is the zone of living oysters in a reef. The degree of ecosystem services provided by the oysters depend on the composition and growth of the reef. This project explored how reef composition is affected by differences in tidal regime and composition, and how, in turn, the degree of ecosystem services might be affected by such differences. Cores were taken from patch oyster reefs and fringing oyster reefs in order to compare the organic matter, shell content, TAZ thickness, and reef depth between sites. Differences were observed between study sites and within reef types. This project shows that reefs in a greater tidal range indicate that they can provide a greater degree of certain ecosystem services to the environment.
Advisor: Gabriela Valdivia (Geography )
Abstract: Refineri??a Esmeraldas greatly influences the well-being of Esmeraldas residents. Analyzing the extent of the refinery's influence on the local communities is important as it provides insight into the environmental suffering occurring in the city. In previous research, I found that residents of the city perceive that the impacts of the refinery are not always direct, but rather affect various aspects of their lives like health and household economies. A theme that emerged in this study was (Dis)Able Bodies, which depicts how oil refining negatively affects the bodies of people. Under the framework of political ecology, I seek to explain how biological, physical, and political environments affect the production of able and disable bodies. Health is important to residents of the city as it allows for greater economic productivity. In this research, I depict how health is affected in this space and across temporal scales, such as how epigenetics appear to be affecting the health of residents beyond one generation. I also compare the nature of environmental suffering taking place in Esmeraldas to other regions participating in any facet of extractive industries. This study has important implications for understanding the oil-driven world we have become comfortable with. It also indicates a need to restructure energy generation so that it does not continue to yield inequalities of such magnitude.
Advisor: Xiaoming Liu (Geology)
Abstract: On February 2nd, a water main break caused a severe shortage of potable drinking water in Orange County. While OWASA (Orange Water And Sewage Authority) worked to solve this problem, a sharp decrease in water pressure prompted Do-Not-Use and Do-Not-Drink orders which lasted until February 5th. While OWASA has published lab results within the allowable limits for fluoride, E. Coli, and pH, the decrease in pressure introduces a small possibility of trace metal contamination by backflow. In this study, drinking water samples taken from various locations around Chapel Hill before and after the water emergency are analyzed using ICP-MS (Inductively Coupled Plasma Mass Spectrometer). The results will allow us to observe any changes in the concentration of potentially toxic trace metals such as lead, chromium, and cadmium which may be attributed to contamination during the water emergency.
Advisor: Karl Castillo (Marine Sciences)
Abstract: Massive reef-building corals are increasingly used as valuable proxies for environmental records due to semiannual density growth bands deposited within their skeletons. The bands, arising from seasonal patterns in light and temperature, reflect both short-term variability and long-term trends in environmental conditions. Conflicting reports about the apparent timing of semiannual high- and low-density coral growth bands has led to uncertainty about the physiological and environmental factors driving their formation. Consequently, this uncertainty may confound the ability to interpret the source and timing of environmental signals reflected in a coral's growth history. Here, we analyzed 16 cores extracted from Siderastrea siderea colonies on the Florida Reef Tract to investigate how the timing of band deposition may be influenced by several factors that have previously been shown to play a role, including colony extension rate and size, tissue thickness, and gender. Growth records and the timing of density band deposition were obtained from the cores via computed tomography. Tissue thickness was measured at the top of the cores, and gender was determined using histological techniques. Preliminary results suggest that the current understanding of banding timing and the factors influencing it may be insufficient to resolve the observed discrepancies in our S. siderea cores.
Advisor: Gabriela Valdivia (Geography)
Abstract: Latin America possesses some of the earth's largest deposits of natural resources and oil reserves. In Ecuador, the petrochemical state grew with promises of oil investment helping the impoverished. Esmeraldas has Ecuador's largest state-owned oil refinery, it is home to a primarily Afro-descendent population. Despite the promises of economic well being from the refinery, the city lives in economic precarity (Valdivia, 2017). The residents of Esmeraldas deal with their precarity through many different ways, whether it's through dependence on the state for cash transfers or informally selling food and other products, the community struggles to make ends meet. By looking at 2014 household economic survey data, this research investigates the variability by which individuals in Esmeraldas make ends meet, and assesses whether oil-related policies of social investment affect income generation. Environmental injustices from extractive industries such as Esmeraldas' oil refinery can play out in number of direct and indirect ways, including through economic externalities. This research aims to explore the precarious conditions of employment in the city contrary to the proposed economic opportunity that the refinery is perceived to bring. Citation: 2017 Valdivia, G. "At the Margins of Citizenship: Uneven Development and the Revoluci??n Ciudadana in Esmeraldas, Ecuador." In Race and Rurality in the Global Political Economy, Michaeline Critchlow, ed., Fernand Braudel Center for the
Advisor: Leslie Hicks (Chemistry)
Abstract: Photosynthetic organisms use dynamic post-translational modifications to survive and adapt, which include reversible oxidative modifications of protein thiols that regulate enzymatic structure, function, and activity. This is particularly relevant for Chlamydomonas reinhardtii, a model alga for the study of photosynthesis and biofuel production. Identification of reversible oxidation sites are key, therefore, to maximize production by improving fitness and stress adaptability. Since reversibly oxidized thiols are substoichiometric and perturbed by experimental conditions, measurements of proteinaceous cysteines have been difficult to obtain. The optimization of a method for highly efficient and specific enrichment of reversibly oxidized cysteine residues from intact proteins is described.
Advisor: Laurie McNeil (Physics)
Undergraduate Co-Authors: Cordell Corbin
Graduate Student Contributors: Britta Gorman
Faculty/Postdoc Contributors: Xuezheng Cao, Timothy O'Brien, Paul Maddox
Abstract: The goal of this project is to measure the elastic constant of the extracellular matrix (ECM), which is primarily collagen, after cancerous cells have metastasized. This is a joint project with Cordell Corbin. I create samples, perform measurements on them, and collaborate with other contributors on the creation of a computer model to simulate and predict experimental results. For sample creation, I make an aqueous collagen solution with a concentration of 2.8 mmol/L and calculate the time and concentration of collagenase needed to split a given percentage of collagen bonds. The collagenase reaction is catalyzed by calcium chloride and quenched by EDTA. The elastic constant of samples with 12.5 ??? 75% of bonds split was then obtained via Brillouin Scattering, an optical technique that measures acoustic speeds in a non-destructive manner. These data will be used as a model for the expected effect of cancerous cells on the ECM. I will create more collagen samples and use cancer cells to split the molecular bonds in a similar manner to the collagenase, then measure the elastic constants of those samples. The LAMMPS Molecular Dynamics Simulator is being used to create a computer simulation of the experiments. The results of this project will provide insight into the effects of cancer on the surrounding matrix, which can show how a cancer metastasizes throughout the body.
Advisor: Laurie McNeil (Physics and Astronomy)
Undergraduate Co-Authors: Harry Heyworth
Graduate Student Contributors: Britta Gorman
Faculty/Postdoc Contributors: Xuezheng Cao, Tim O'Brien, Paul Maddox
Abstract: The goal of this project is to measure the elastic constant of the extracellular matrix (ECM), which is primarily collagen, after cancerous cells have metastasized. This is a joint project with Harry Heyworth. I create samples, perform measurements on them, and collaborate with other contributors on the creation of a computer model to simulate and predict experimental results. For sample creation, I make an aqueous collagen solution with a concentration of 2.8 mmol/L and calculate the time and concentration of collagenase needed to split a given percentage of collagen bonds. The collagenase reaction is catalyzed by calcium chloride and quenched by EDTA. The elastic constant of samples with 12.5 ??? 75% of bonds split was then obtained via Brillouin Scattering, an optical technique that measures acoustic speeds in a non-destructive manner. These data will be used as a model for the expected effect of cancerous cells on the ECM. I will create more collagen samples and use cancer cells to split the molecular bonds in a similar manner to the collagenase, then measure the elastic constants of those samples. The LAMMPS Molecular Dynamics Simulator is being used to create a computer simulation of the experiments. The results of this project will provide insight into the effects of cancer on the surrounding matrix, which can show how a cancer metastasizes throughout the body.
Advisor: Gary Glish (Chemistry)
Abstract: Paper spray is a relatively new ambient ionization technique used to generate ions for the detection by mass spectrometry. Analytes are deposited onto a paper substrate laser cut to a sharp tip, and ions are produced from the emitter when a spray solvent and high voltage is applied to the paper. The technique has been used for a variety of applications, however the amount of energy imparted to analytes ionized this way is not well characterized. Fragmentation occurs when ions gain enough internal energy to break bonds. The well-studied "thermometer ion" methoxybenzyl pyridinium is used to investigate the amount of internal energy imparted by paper spray ionization. Benzyl pyridinium salts have a permanent charge and fragment by simple cleavage, with the amount of energy required for fragmentation being related to the substituent on the pyridine. Both commercialized (Velox 360) and custom-built paper spray instruments are used to test variables that can affect the amount of fragmentation. Some of these variables include the distance from the tip to the inlet of the mass spectrometer in xyz directions, temperature of the inlet, and the total voltage applied.
Advisor: Gaorav Gupta (Radiation Oncology)
Abstract: Background: DDR is crucial for maintaining genomic stability by detecting and repairing damage to cellular DNA, and by eliminating cells with irreparable DNA1. Disruption of the DDR is observed in many cancers and is hypothesized to contribute to the mutagenic processes driving tumorigenesis2. We propose to implement a customized CRISPR library targeting 310 DDR genes to identify the genes that are essential for viability after DNA damage induced by IR, different classes of chemotherapeutics, and various inhibitors in a uniform cancer cell line model. Methods: 1) CRISPR pooled screening and library preparation is used to allow for lentiviral-based delivery of individual small guide RNAs (sgRNAs) into cells in order to perform large-scale functional genetic screens. 2) Growth-dependent changes in sgRNA representation is used to for selected chemotherapeutic drugs and ionized radiation. 3) For genes that are identified as required for repair of damage induced by the different DDAs, we analyzed TCGA using the cbioportal. Results and Conclusion: Treatment group to the control samples are compared to identify sgRNA sequences that are depleted specifically in the treated sample(s); These depleted sgRNAs are predicted to target genes that are essential for repair of DNA damage induced by that treatment.
Advisor: Barry Popkin (Nutrition)
Abstract: This study examines nutrition transition in Chinese adolescents aged 12 to 17 years old. Changes in macronutrient composition of diet and intake levels of sodium and potassium were analyzed for temporal trends. Dietary data was collected from the China Health and Nutrition Survey using individual level, consecutive 3-day 24-hour recalls from survey years 1991 (n=489), 2000 (n=677), and 2011 (n=253). Sodium and potassium were analyzed as Na/K ratios. Linear regression models of macronutrient and Na/K ratio intakes were constructed to predict means with respective standard errors and adjusted for covariate sociodemographic variables. From 1991 to 2011, energy intake decreased in low, middle, and high urbanicity cohorts (2592 kcal/d to 1691 kcal/d, p<0.001; 2382 kcal/d to 1804 kcal/d, p<0.001; 2358 kcal/d to 1938 kcal/day, p<0.001 respectively). Percent carbohydrate intake of daily calories decreased in all three urbanicity cohorts (68.1% to 57.9%, p<0.001; 61.7% to 53.6%, p<0.002; 62.0% to 53.2%, p<0.014 respectively). The low and middle urbanicity cohorts showed increased percent fat intake of daily calories (20.8% to 29.6%, p<0.001; 26.1% to 33.6%, p<0.004 respectively). For percent protein intake of daily calories, the low and high urbanicity cohorts showed significant increase (11.0% to 12.5%, p<0.001; 12.5% to 13.7%, p<0.0002 respectively). Na/K ratios decreased in all urbanicity cohorts (5.02 to 2.65, p<0.004; 4.21 to 3.49, p<0.0002; 3.41 to 2.33, p<0.0008 respectively).
Advisor: Natasha Snider (Cell Biology and Physiology)
Undergraduate Co-Authors: Deekshita Ramanarayanan
Faculty/Postdoc Contributors: Dr. Natasha T. Snider
Abstract: Chronic liver injury is one of the fastest growing pathologies in the United States. CD73, or ecto-5???-nucleotidase (NT5E), has been linked to liver injury in recent years. CD73 is a membrane protein that catalyzes the conversion of extracellular AMP to adenosine, and has been found to be upregulated in several human carcinomas. It was discovered to play a role in drug induced liver injury, and was also shown to have protective effects in ethanol-induced hepatic steatosis as well as other hepatocyte-specific injury. In order to determine the liver-specific function of CD73, we generated a hepatocyte-specific CD73 knockout mouse model using the cre/lox system. We characterized the properties of this mouse model through Western Blot, serum profiling, qPCR and enzyme histochemistry. We found that CD73 knockout mice were more prone to fatty livers, and to developing hepatic steatosis at a later age without inducing injury. We also found that the female knockout mice had decreased albumin levels, which is indicative of potentially compromised liver function. Through qPCR analysis, we found that components of the AP1 transcription factor complex are more highly expressed in the knockout mice. Characterization of these hepatocyte-specific knockout mice may result in determining the tissue specific or the non-enzymatic function of CD73, which would prove useful in targeting CD73 for therapy in different disease states.
Advisor: Johna Register-Mihalik (Exercise and Sport Science)
Faculty/Postdoc Contributors: Johna K. Register-Mihalik
Abstract: Most youth athletes do not have access to high-level medical care on the field due to their age. Coaches are often the initial care-providers in the case of injury. As such, it is important for youth sport coaches to have appropriate attitudes and knowledge about concussions to recognize potential injuries. Thus, the purpose of this study was to determine whether sport influences coach knowledge and attitudes about concussions. A convenience sample of 81 youth coaches from North Carolina and Arizona participated in this study. Cross-sectional surveys were distributed to coaches who represented three middle schools and 21 youth teams. 86.25% of coaches were male. 42.5% had received concussion education, and 45% coached football. Overall mean knowledge score was 19.5 (3.3) out of a maximum 29. Mean attitude score was 40.6 (2.7) out of 49. Two one-way ANOVA's were run to examine the effect of sport on concussion knowledge and attitudes toward concussion. There was insufficient evidence to conclude that sport has an effect on either concussion knowledge (p=0.7044) or attitude (p=0.8049) toward concussion in youth coaches. To improve overall concussion knowledge and attitudes, it is important to understand what factors contribute to baseline levels. These findings suggest that sport does not affect youth coaches' knowledge or attitudes toward concussion. However, knowledge scores overall were low, highlighting the necessity of concussion education in youth coaches across all sports.
Advisor: Darin Padua (Exercise and Sport Science)
Abstract: Context: Sport-related lower extremity injuries often occur when an athlete is not properly allocating attention during a functional task, such as landing and cutting. Little research has been done to determine how attention allocation may lead to injury or how an individual's lower extremity biomechanics during functional tasks respond when paired with a concurrent cognitive task. Given the importance of attentional focus and lower extremity biomechanics on lower extremity injury, it is crucial to understand how these variables interact. Objective: To determine the effects of a Symbol Digits Modality Test (SDMT) on jump-landing biomechanics in physically active males and females. Materials and Methods: 21 participants volunteered in a controlled research lab. Participants had to play football, rugby, soccer, basketball, or lacrosse at least once a week, have no history of lower extremity surgery, and been cleared for play for at least 6 months following a concussion. Participants completed baseline SDMT (3 trials); then an alternating jump-landing task during simultaneous SDMT (3 trials) and jump-landing task without simultaneous cognitive task (3-trials) in randomized controlled trials. An expert rater scored standard videos of the frontal and sagittal views using the landing error scoring system (LESS) to evaluate lower extremity biomechanics. Results/Conclusion: Results and conclusion to be stated upon completion of research study.
Advisor: Tamara Berg (Computer Science)
Abstract: Automatic video captioning is a task in which a machine must generate a sentence describing a given video sequence in a natural language (e.g., English) without human intervention. This can be useful for describing situations in which users cannot perceive a scene visually. Advances in artificial intelligence, computer vision, and natural language processing have made image and video captioning somewhat possible, but these generated captions still lack specificity and accuracy. I present work towards improving methods in video captioning by incorporating domain knowledge which can be learned from the Web. The task is isolated to videos in the cooking domain; there are a variety of sources of related knowledge on the Web from which we can draw information, such as cooking recipes and instructional videos. From these, we can computationally learn temporal relationships about states of cooking ingredients (e.g., a whole apple precedes a sliced apple) and visual models (e.g., an apple can be red or white depending on its state), and use both to improve the representation of the video for captioning.
Advisor: Jane Monaco (Biostatistics)
Abstract: Every year, the North Carolina State Center for Health Statistics (SCHS) collects data on women between the ages of 10 and 50 who died within a year of giving birth. These deaths are collectively referred to as "maternal deaths" and have a variety of causes, including drugs, automobile accidents, and the pregnancy or birth itself. This project uses SCHS data to analyze maternal deaths by cause from the years 1999 to 2013. According to these data, the number of deaths from year to year was between 36 and 75. Of those deaths, an average of 22 women died of pregnancy or birth-related causes each year. The question is: Has there been any consistent trend over time due to any particular cause of death? Analysis of these data is affected by several factors: small sample sizes, changes in regulatory requirements for reporting, and the need to maintain the privacy of the women and families involved. Descriptive statistics and linear regression models were calculated using statistical software (SAS 9.4). Initial findings indicate that there has been no linear increase or decrease in maternal deaths due to some causes, such as automobile accidents and homicide. However, there has been a statistically significant linear increase in deaths due to drugs. An objective statistical analysis of maternal death data is critical to developing public policy measures to prevent such deaths.
Advisor: Donita Robinson (Psychiatry at the Bowles Center for Alcohol Studies)
Faculty/Postdoc Contributors: Aric Madayag
Abstract: An increasing number of people experience addiction to substances, which often has profoundly detrimental cognitive, health, and social consequences. For that reason, investigation of the neural circuitry that can produce addiction vulnerability is exceedingly important. In this study, a rat model was utilized to try to delineate the functions of a specific cortico-striatal pathway in the brain. Optogenetics was used to activate the projection neurons from the lateral orbitofrontal cortex (lOFC) to the dorsolateral striatum (DLS), as both of these brain regions have been implicated in having an important role within the brain's addiction and reward circuitry. Stimulation was administered while rats completed a classical conditioning session in a behavior chamber. The paradigm of choice was Pavlovian conditioned approach, which allowed us to observe attentional biases to either a cue-predictive lever (interaction with which has been shown to be related to addictive tendencies) or a reward receptacle (interaction with which is indicative of goal-directed behaviors). It was originally posited that stimulation to this pathway would enhance negative feedback from the lOFC to the DLS, thereby inhibiting behaviors related to addictive tendencies (indicated by a cue bias towards the lever). However, the data seem to more strongly suggest that the role of this pathway influences goal-directed behaviors, as demonstrated by increased receptacle entries and decreased latencies.
Advisor: Jean-Louis Gariepy (Psychology and Neuroscience (Developmental))
Faculty/Postdoc Contributors: Nicole Garder-Neblett
Abstract: Racial discrimination may be conceptualized as a unique, chronic stressor that impacts the lives of African-American/Black individuals, and is associated with a multitude of negative mental and physical health outcomes. Specifically, frequent racial discrimination has been repeatedly associated with increased anxiety symptomology. The present study was designed to elaborate upon this relationship by assessing intraindividual differences in the autonomic reactivity of Black undergraduate students. These differences in reactivity were examined by the careful monitoring of changes in respiratory sinus arrhythmia (??RSA) and heart rate during a laboratory task designed to mimic a real-life encounter with racial discrimination. Participants completed both an online questionnaire and a laboratory visit in which electrocardiogram data were collected. Multiple regression analyses indicate that both ??RSA and heart rate reactivity significantly moderate the relationship between frequency of racial discrimination and anxiety symptomology, even when controlling for age, gender, and parental education. These results suggest that future research examining the negative effects of racial discrimination might profitably place more emphasis on autonomic reactivity in order to better understand and predict health outcome trajectories, as well as identify those individuals who may be at risk.
Advisor: Eric Brustad (Chemistry)
Abstract: All cells rely on oxidation-reduction reactions. These redox reactions generate a variety of reactive oxygen species (ROS), such as hydrogen peroxide (H2O2). ROS also have important implications in health and treating disease, as unbalanced levels of ROS in cells are linked to certain diseases. Current biological ROS sensors have high limits of detection and are restricted to specific species. ROS exist in cells for short bursts, making them difficult to measure. We were able to engineer a mutant enzyme that reacts with hydrogen peroxide to produce a detectable colorimetric signal. The unnatural amino acid p-boronophenylalanine (BoF) was incorporated into the active site of ??-galactosidase to act as a molecular ???switch??? to activate the enzyme in the presence of ROS. ??-galactosidase then catalyzes a reaction resulting in a fluorescent or colorimetric signal. While only qualitative data has been gathered, more quantitative kinetic analyses will be done in the future.
Advisor: Richard Loeser (Department of Cell Biology (School of Medicine))
Abstract: Osteoarthritis (OA) is the most common form of arthritis and one of the leading causes of pain and disability in older adults. Human chondrocytes that have high expression of Matrix Metallopeptidase 13 (MMP-13) experience matrix destruction, which results in cell deterioration and death. MMP-13 is key in OA since it is the enzyme that is primarily responsible for the degradation of type II collagen, a key structural protein in the joint. MMP-13 activity is regulated by mitogen-activated (MAP) kinase proteins, which also control multiple cell signaling pathways. The purpose of this study was to identify the role of the cytoskeleton in the release of MMP-13 in human chondrocytes using the reagent Cytochalasin D, a mycotoxin that restructures the cytoskeleton by the inhibiting actin polymerization. Levels of MMP-13 and reactive oxygen species release were measured and phosphorylation of MAP kinases was observed. ??It was seen that Cytochalasin D increases production of MMP-13. The findings of this study suggest that (1) correlation between inhibition of actin polymerization and release of MMP-13 and (2) the disruption of cytoskeletons results in the activation of catabolic cell signaling pathways in human chondrocytes. While other studies have demonstrated the effect of Cytochalasin D on the physical restructuring of the cytoskeletal networks, this study was the first to analyze the effects of the cytoskeleton rearrangement on MMP-13 levels in chondrocytes.
Advisor: Matthew Parrott (Radiology)
Abstract: The activation of tumor-infiltrating lymphocytes (TILs) has become a prominent immunotherapy technique for the treatment of various cancers. However, the ability to evaluate the patient response to these treatments has been limited because it relies on counting the number of immune cells that are recruited during therapy. One novel, unexploited approach for monitoring the efficacy of immunotherapy is to quantify immune cells by way of positron emission tomography-computed tomography (PET/CT) imaging. The CD3 antigen, which is uniquely present in T-cell receptors at all stages of T-cell development, makes it a useful target for the imaging of T-cells. Thus, the CD3 antigen is also a natural point of interest for the early evaluation of the efficacy of immunotherapy. To target the CD3 antigen, we use antiCD3 antibody fragments, rather than full antibodies, because they exhibit better tissue penetration, more rapid clearance from the blood, and thus less radioactive exposure to the patient. Overall, this project takes advantage of techniques in enzymatic proteolysis and antibody binding behavior to evaluate the biodistribution of an antiCD3-F(ab???)2 fragment in vivo ??? and serves as a basis for subsequent development of antiCD3 fragments as powerful diagnostic tools for evaluating the efficacy of cancer immunotherapy treatments.
Advisor: Mohanish Deshmukh (Department of Cell Biology & Physiology)
Abstract: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease where motor neurons die and eventually leads to the inability of the brain to initiate and control muscle movement. Approximately 10% of ALS cases are classified as familial ALS, as opposed to sporadic ALS (≈90%). Familial ALS has been associated with certain genetic mutations, many of which affecting the enzyme Superoxide Dismutase (SOD) and possibly leading to its destabilization. Therefore, drugs that stabilize SOD offer a potential therapeutic window for ALS. This study examines the effect of introducing several SOD-mutation plasmids into the motor neuron-like cell line, NSC-34, and assessing cell death. Our goal is to use this assay to test several SOD-stabilizing drugs on their ability to reduce cell death in the presence of SOD-destabilizing mutations.
Advisor: Chad Pecot (Medicine)
Abstract: The KRAS gene has been implicated as a driver mutation in nearly one third of all cancers. However, it remains an elusive target for molecular therapy and harder still to selectively knock down while sparing the wild-type allele. Thus, the purpose of this investigation was to determine the efficacy of novel custom mutant-specific (MS) siRNA sequences in targeting multiple mutant KRAS alleles over the wild-type. To do so, NIH 3T3 mouse fibroblasts that had been infected with wild-type, G12C, G12D, G12V, and G13D mutant human KRAS were reverse transfected with 3 control sequences, 2 sequences designed to be anti-sense to a single mutation each (G12C and G12D), and 12 novel MS siRNA sequences that target 3 mutations each. Levels of mRNA transcription were quantified using reverse transcription followed by real-time PCR. Current results indicate that the G12CD13D_1, G12CD13D_2, and G12CD13D_4 siRNA sequences exhibit higher knockdown of the mutant alleles while maintaining expression levels of WT KRAS that are comparable to the negative control siRNA. By contrast, neither of the single mutant siRNA sequences showed any particular affinity for their target mutants over either the other mutants or WT KRAS. As such, with their potential as an effective payload with mutant KRAS specificity, novel MS siRNAs present a promising avenue of pursuit for drugging the formerly "undruggable."
Advisor: Karin Yeatts (Epidemiology)
Abstract: Gastrointestinal diseases for children under 5 in Lima, Peru is endemic especially in lower-socioeconomic areas. The clinic of San Martín de Porres in the district Villa el Salvador, a lower socioeconomic area that used to be a slum has ~15% of children under 5 with Giardia lamblia, 3-5% with Ascaris lumbricoides, and 1-2% with Taenia solium (clinic statistics) which all cause diarrhea and dehydration. After working with the clinicians and observing in the laboratory, we developed a survey based on the clinic's interest in the main factors contributing to the spread of these diseases, including children's views on hand washing, handwashing frequency before and after certain activities, and stomach pains and sickness episodes per month. We distributed the UNC IRB exempted survey at a district wide health campaign and 20 children under 13 consented to participate. In addition to distributing surveys, a hand washing demonstration for all children (consenting to survey or not) was done based on the Peru Ministry of Health recommendations. We found that children who reported belief that hand washing prevents illness had less sickness episodes per month versus those who did not (means of 1.42, 1.86). The frequency of hand washing was also related to a mean decrease in sickness episodes and stomach pain episodes. We used our findings on the most pertinent issues and ideas about sanitation to create a hand washing poster for the clinic.
Advisor: Johna Register-Mihalik (Exercise and Sport Science)
Abstract: The quarterback (QB) is arguably the most valued player on any National Football League (NFL) team due to their role in decision-making and leadership. Thus, they are susceptible to impacts from opponents, possibly resulting in concussion. Post-concussion performance can indicate whether NFL QBs are recovering fully to their pre-injury performance level before returning to the field. The purpose of this investigation was to compare NFL QB performance in the 3 games prior to and following concussion describing the effect of concussions on passing performance. Performance was analyzed via completion percentage of passes thrown. Publicly available online databases were searched for injury reports and player statistics. 36 concussions were found over the past 5 seasons (x ??=7.2??3.27 per season) among QBs. The mean number of games missed due to concussion was 1.78??3.05. The data collected show an increase in completion percentage in the games post-injury (61.55??9.53 vs. 64.59??7.32). Of the 36 injuries, 9 resulted in the QB not returning to another game that season. These findings suggest that based on publicly available data, QB pass performance does not decline following concussion, perhaps showing that players and teams are taking proper safety precaution before returning to games. However, not all individuals were able to return to the playing field. More research needs to be done to explore specific reasons for why some athletes improve while others are unable to return.
Advisor: David Penn (Clinical Psychology )
Abstract: People with first episode psychosis (FEP) are often reluctant to seek treatment, resulting in difficulties engaging clients and high dropout rates. The therapeutic alliance (TA), the affective and collaborative bond between therapist and client, is predictive of better treatment outcomes for clients with FEP; thus, it is valuable to study the predictors of the TA to elucidate how best to foster a positive alliance and identify strategies to effectively engage these individuals in treatment. The current study examined baseline client characteristics including severity of symptoms, social functioning, duration of untreated psychosis, and demographic factors (age, race), as potential predictors of the TA within Individual Resiliency Training (IRT), the individual therapy developed for the NIMH Recovery After An Initial Episode Early Treatment Program. Subjects (n=146) were assigned to a trained IRT therapist, and sessions were audio recorded. Four undergraduate students were trained in using the Vanderbilt Therapeutic Alliance Scale to rate the TA between client and therapist for session 3 of IRT. Results indicated a significant positive relationship (t(137) = 2.91, p = 0.004) between positive symptoms, a significant negative relationship between negative symptoms and the TA (t(138) = -3.49, p = 0.0007) as well as excitative symptoms and the TA (t(137) = -3.02), p = 0.003), and a significant positive relationship between age and the TA (t(132) = 2.34, p = 0.02).
Advisor: Rachael Kang (Psychology and Neuroscience)
Graduate Student Contributors: Tate Halverson, Mian-Li Ong
Faculty/Postdoc Contributors: Eric Youngstrom
Abstract: Circadian rhythms, which are closely related to mood and energy, are controlled by blue light and can be disrupted by transmeridian travel. This study evaluates the efficacy of blue-light blocking glasses in reducing sleepiness and negative affect associated with jetlag. 18 participants were enrolled from a summer program at Korea University in Seoul, South Korea. They were randomly placed into either (a) blue-light blocking glasses group or (b) no glasses group. Participants were followed before and after their travel home, taking the Stanford Sleepiness Scale to measure sleepiness, and the Positive and Negative Affect Scale to measure mood. Independent samples t-tests indicated no significant differences between the sleepiness scores of the two groups (p>.01), and no significant difference in positive affect scores between the glasses group (Mp=25.55, SDp = 7.84) and the no glasses group (Mp=22.16, SDp=5.97); tp(117)=2.59, p=.011. There was a significant difference between the negative affect scores of the glasses group (Mn=11.98,SDn=3.61) and the no glasses group (Mn=13.92, SDn=3.74); tn(119)=-2.72, p=.008. These results suggest that while the overall sleepiness of the participants remained unaffected by the blue-light blocking glasses, their affect was less negative. The glasses triggering the release of melatonin could be consistent with this. The individual would receive the benefits of the increased melatonin in their systems, without actually getting more sleep.
Advisor: Gary Glish (Chemistry)
Graduate Student Contributors: James Keating, Sally Hunsucker
Faculty/Postdoc Contributors: Paul Armistead, Gary Glish
Abstract: T cell-based therapies offer a promising means of treating leukemia more selectively than commonly used radiation and chemotherapies. The efficient development of these therapies requires the ability to confirm the presence of immunogenic antigens in patient samples. The amino acid sequences of leukemia peptide antigens can be computationally predicted, but development of therapies for the huge number of computationally predicted peptides is unrealistic. Detection of these peptides in tumor cells would provide targets that could be realistically targeted for therapeutic development. Differential ion mobility spectrometry (DIMS) coupled to mass spectrometry provides a powerful platform for the detection of these peptides, as the sensitivity and selectivity of the mass spectrometer is complemented by the rapid separation and filtering capabilities of DIMS. Previous work in our group has confirmed the presence of a known leukemia peptide antigen, CG1 (FLLPTGAEA), in leukemia cell lines using DIMS-MS. Peptides isolated from the U937.A2 leukemia cell line were analyzed using CG1 as a positive control to understand the impact of peptide isolation work flow. Mixtures of the predicted peptide standards were used as models for DIMS separation. The effects of dispersion field strength, carrier gas temperature, and addition of solvent modifiers on the separation and transmission of peptide antigens were explored and used to optimize detection methods.
Advisor: Jon Abramowitz (Psychology)
Abstract: Anxiety sensitivity (AS), the fear of arousal-related physiological sensations, is a predictor of post-traumatic stress symptoms (PTS) following a traumatic event (Boffa et al., 2016; Olatunji & Fan, 2015), yet there is limited research on the relationship between AS and PTS among sexual assault survivors. Accordingly, the present study examined AS as a predictor of PTS symptoms among members of a campus community who reported experiencing a sexual trauma. A total of 54 adults completed an online battery of self-report measures of AS, general distress, and dysfunctional "posttraumatic" cognitions known to predict PTS. Three linear regressions were computed, one for each subscale of the PTSD Symptom Scale (PSS; i.e., re-experiencing, avoidance, arousal). All regression models explained significant variance in PSS scores. Posttraumatic cognitions were the only significant individual predictors of avoidance and re-experiencing, yet both AS and posttraumatic cognitions were significantly predicted arousal symptoms. Although cross-sectional, this study has potential implications for understanding the role of AS in PTS among sexual trauma survivors. In particular, AS appears to be associated only with the arousal symptom domain of PTS. Future directions and limitations of this study will be discussed.
Advisor: Gary Glish (Chemistry)
Abstract: Hexose sugars are monosaccharides, the basic functional units of all carbohydrates. This project focuses on using mass spectrometry to differentiate hexosamines and N-acetylated hexosamines, which are monomeric units of several structural polymers and prominent precursors of glycosylated linkages between carbohydrate, protein, and lipids. Mass spectrometry is an analytical technique that analyzes and separates complex mixtures based on the masses of the individual components. It is the ideal analytical method because samples can be analyzed much faster and without excessive preparation. Hexoses are isomers of each other, meaning they contain the same atoms rearranged differently. Isomers have the same molecular weight, so they are traditionally difficult to distinguish using mass spectrometry. However, we have developed a non-conventional mass spectrometric approach to allow the different ions to be identified.
Advisor: Abbie E. Smith-Ryan (Exercise and Sport Science)
Faculty/Postdoc Contributors: Abbie E. Smith-Ryan
Abstract: Lack of sleep, stress, and processed food consumption have been shown to compromise gastrointestinal (GI) health. PURPOSE: To explore the potential relationship between nutritional intake and body composition in hospital shift workers. METHODS: Twenty-eight female (Mean ?? SD; Age: 30.7 ?? 8.7 yrs; Height: 165.0 ?? 6.7 cm; Weight: 66.9 ?? 10.9 kg) rotating or night shift healthcare workers volunteered for the current study. Participants completed a 3-day food log to reflect habitual protein (PRO), fat, carbohydrate (CHO), and daily caloric intake. Body composition variables [fat mass (FM), fat free mass (FFM), and percent body fat (%BF)] were measured via bioelectrical impedance spectroscopy. Regional fat distribution was estimated using visceral fat depth from ultrasound (VAT) and waist-to-hip ratio (WH). The Harris Benedict equation was used to calculate estimated energy requirements (EER). RESULTS: There were no significant correlations between PRO, fat, CHO, or total calories and body composition outcomes (p>0.05). Visceral fat was significantly related to WH (R=0.647, p<0.001). Evaluation of total caloric intake and EER suggests that a majority of participants under-consumed calories (61%). CONCLUSIONS: Contrary to expectation, dietary intake was not significantly related to body composition variables. This suggests that other factors such as stress, impaired sleep cycles, or inconsistent food consumption may influence body composition and fat distribution in shift workers.
Advisor: Brian Pietrosimone (Exercise and Sport Science)
Abstract: Osteoarthritis is preceded by subclinical alterations in articular cartilage. Joint biomechanics are associated with changes in cartilage thickness and could predict risk for OA development. This study determined the associations between acute femoral cartilage deformation in the medial, lateral, and intercondylar compartments of the knee and peak vertical ground reaction force (vGRF) and instantaneous vGRF loading rate during walking in healthy individuals. Femoral cartilage thickness in the three compartments was measured with ultrasound before and after the walking protocol. Cartilage deformation was calculated as the percent change between the two measurements. Five walking gait trials were recorded in a motion capture laboratory to assess biomechanical variables. Participants walked for 5000 steps on a treadmill. Pearson product-moment correlations evaluated the associations between biomechanical and ultrasound variables. Instantaneous vGRF loading rate was significantly positively associated with lateral femoral cartilage deformation (r=0.335, P=0.039, n=38), indicating that less cartilage deformation associated with a higher loading rate. No significant associations were found between other measures. Lateral condyle deformation was more associated with rate of loading than magnitude of loading during walking. The lack of associations between other variables indicates that loading may differentially affect other portions of the femoral surface.
Advisor: Ronald Chen (Radiation Oncology)
Abstract: Often, when a patient is diagnosed with cancer, the patient's other medical conditions become ignored or considered less important. However, prostate cancer is a disease of the elderly, and many patients may have other important medical issues which need to be addressed during cancer treatment and in subsequent follow-up. In addition, a common form prostate cancer treatment, androgen deprivation therapy, can increase risk for heart disease and diabetes. In this project, patients from all 100 counties across North Carolina with newly-diagnosed prostate cancer were enrolled on a clinical study; the presence of other medical conditions was ascertained by reviewing their medical records. The well-established Charlson Comorbidity Index and the Adult Comorbidity Evaluation-27 were utilized to score the extent of comorbid medical conditions. The study shows a high prevalence of heart disease and hypertension among prostate cancer patients. Ultimately, this study supports the need for continued primary and preventive care in the cancer population to best manage these important medical conditions even after a cancer diagnosis.
Advisor: Abbie Smith-Ryan (Exercise and Sports Science)
Abstract: Purpose: To evaluate the effects of protein supplementation compared to standard care in bariatric surgery patients. Methods: Thirteen patients (Age: 42.9 ?? 10.4 yrs; Height: 162.5 ?? 6.2 cm; Weight: 323.2 ?? 72.9 lbs) volunteered for the study. Following random assignment to protein supplementation (PRO; n=4) or standard of care (SOC; n=3), seven patients completed a follow-up visit 3 weeks post-surgery. Resting metabolic rate (RMR) was determined via portable indirect calorimetry. Body composition [fat mass (FM), fat free mass (FFM), and percent body fat (%BF)] was measured via bioelectrical impedance spectroscopy. Functional fitness was determined from the 30-second chair stand test. Results: Baseline mean RMR was 2120.7 ?? 574.1 kcals. Mean FM=144.3 ?? 36.4 lbs, FFM=178.9 ?? 48.2 lbs, and %BF = 44.8 ?? 6.1%. Average chair stand was 12.2 ?? 3.7 repetitions. While there was no significant difference in RMR three weeks post-surgery (p=0.057), RMR in PRO was generally maintained (-26.3 ?? 175 kcals) and decreased in SOC (-552 ?? 275 kcals). There were no significant differences for FM (-5.3 ?? 9.6 lbs; p=0.321), FFM (-18.1 ?? 10.2 lbs; p=0.139), or %BF (-1.2 ?? 2.1 %; p=0.653). There was no difference in chair stand results between groups (p=0.627). Discussion: Despite being statistically nonsignificant, an RMR difference of over 500 kcals is meaningful in the context of weight loss. Reduced RMR may facilitate weight regain or prevent weight loss due to decreased caloric expenditure.
Advisor: C. Ryan Miller (Graduate Program in Pathobiology and Translational Sciences )
Graduate Student Contributors: Robert S. McNeill, Erin Smithberger
Abstract: Glioblastoma (GBM) is the most common and lethal malignant brain tumor. The phosphoinositide 3-kinase (PI3K) pathway is frequently mutated in GBM and its activation can promote tumorigenesis in preclinical models. PI3K is a heterodimeric kinase composed of both regulatory (PIK3R1) and catalytic (PIK3CA) subunits. Pathway activation occurs via phosphorylation of PIP2 to PIP3 by the catalytic subunit. However, PIK3CA mutations have not been studied in relation to gliomagenesis. We previously found that missense mutations in PIK3CA activate PI3K signaling and promote tumorigenesis in immortalized human astrocytes (NHA) and NHA with mutant RAS (NHARAS). We therefore investigated pathway inhibition and alternate pathway activation was investigated using the PI3K inhibitor (PI3Ki) buparlisib (BKM120) and the MEK inhibitor (MEKi) selumetinib (AZD6244) at different concentrations. Buparlisib inhibited proximal (pAKT) PI3K signaling while increasing MAPK (pERK) signaling independent of mutant PIK3CA or RAS status. Selumetinib inhibited MAPK in NHA and NHARAS lines independent of the presence of PIK3CA mutations or mutant RAS. Moreover, Selumetinib increased pAKT in all NHA lines, however, pAKT was only increased in NHARAS lines lacking PIK3CA mutations. These data suggest that PI3K and MAPK are reciprocal bypass pathways and that dual PI3K/MEK inhibitor treatment would be more effective than either drug alone.
Advisor: Stacey Daughters (Psychology and Neuroscience)
Abstract: Cocaine use disorder has wide-ranging social, economic, and health-related consequences, including changes to the neural stress networks that may be linked to deficits in goal-directed behavior. Distress tolerance (DT), or the ability to withstand negative affect during goal-directed activities, is implicated in maintaining substance use disorders. Low distress tolerance (measured behaviorally) has been linked to worse treatment outcomes, shorter abstinence attempts, and more days of substance use. Daughters et al. (2016) validated a measure of DT (the Paced Auditory Serial Addition Task, or PASAT) for an fMRI scanner to examine the neural correlates of DT. As a follow up, the current study used longitudinal data from a sample of 24 regular cocaine and nicotine users to determine if the neural correlates associated with stress could be used to predict future substance use 30 days post-scan. There was a positive correlation between the percentage of days used crack/cocaine and the bilateral amygdala activation in response to stress. This is in line with prior studies regarding the implication of the hyperactivation of the amygdala in anxiety and increased substance use frequency. Future research should utilize a treatment-seeking population of cocaine users to determine whether neural regions linked to DT can predict treatment outcomes and relapse frequency to potentially find biomarkers to target with treatment.
Advisor: Darin Padua (Exercise and Sport Science)
Abstract: Context: During exercise participation muscle mass is leveraged to control human motion. Objective: To investigate the relationship between lower extremity muscle mass and creatine kinase release during controlled exercise. Setting: Research Laboratory Subjects: 43 physically active, healthy, college-aged field or court sport female athletes. Methods: Participants underwent a baseline dual energy x-ray absorptiometry (DXA) scan to obtain body composition information. Blood samples were collected pre and post-exercise. During exercise participants completed 5 sets of a 5-minute graded treadmill run at 110-120% of their ventilatory threshold, followed by 10 jump-landing box jumps off a 30-cm box. Results: A significant positive relationship was observed between creatine kinase response to exercise and lower extremity lean mass normalized to body mass Conclusion: It appears individuals with greater relative muscle mass availability leverage a greater proportion of their muscle tissue volume during exercise compared to individuals with less muscle mass per unit body mass. These results suggest that individuals with greater relative muscle mass may be more mechanically efficient using metabolically active tissue to do work during exercise compared to individuals with less relative muscle tissue volumes.
Advisor: Cathi Propper (Psychology and Neuroscience)
Abstract: Infant physiological regulation was examined with a sample of 90 African American mother-infant dyads. The focus was on the extent to which infant reactivity in normal and stressful scenarios could predict future sleep quality and emotional reactivity. Home visits took place when the infants were 3 and 6 months of age; baseline cardiac data, including measures of respiratory sinus arrhythmia (RSA), were gathered, and sleep assessments (via actigraphy) were conducted during the following week. To gauge the infants' responses to a stressful situation, the still-face paradigm (SFP) was administered at 6 months. Results show 3 month baseline RSA for when infants are in mothers' arms to be significant with 6 month night sleep ratio at the 0.05 significance level (r = .392, p = 009.). Additionally, 3 month baseline RSA when infants are not in mothers' arms was negatively significant with infants looking away from mothers in the reunion episode of the SF at the 0.01 significance level (r = -.329, p = .029). Ongoing analyses will test the effect of sleep quality on 6 month emotional reactivity and physiological regulation in the SFP. This project was made possible (in part) by support from the Office for Undergraduate Research at UNC-Chapel Hill.
Advisor: Dan McKay (Biology)
Faculty/Postdoc Contributors: Aravind Asokan
Abstract: For gene delivery to the central nervous system (CNS), adeno-associated vectors (AAV) must cross the blood-brain barrier (BBB). Producing effective levels of gene expression in the CNS requires high vector doses and consequently can be harmful to non-target organs such as the liver. To increase specificity of AAV vectors to the CNS as well as lower the dosage required, we used residues of two AAV serotypes known for specificity and their ability to cross the BBB. These serotypes, AAV1 and AAVrh.10, were combined to form a library of recombinant capsids that would be specific and able to cross the BBB. Select AAVrh.10 residues were identified to create AAV recombinants that were administered intravenously. These recombinants were detargeted from peripheral tissues while still maintaining their ability to transduce the CNS in vivo. The avoidance of non-target tissues by these recombinants offers support for a safer and more effective viral vector for gene delivery.
Advisor: Gary Glish (Analytical Chemistry)
Abstract: Mass spectrometry using extractive electrospray ionization (EESI-MS) is a method for producing and measuring ions of different masses by intersecting an analyte-containing aerosol and an electrospray of the desired solvent in an applied electric field. Coaxial EESI is a variation of EESI developed in our lab that can be used to measure the complex components of pyrolyzed cellulose, tobacco and other compounds. Compounds in the aerosol are extracted based on solubility, thus the choice of solvent and added acid when performing EESI can greatly influence the mass spectrum obtained from an analysis. No systematic study of EESI solvents has yet been performed for aerosol analysis. This research aims to identify differences in the mass spectrum of pyrolyzed cellulose when different solvents are used for ionization, and identify the solvent mixture which gives the highest intensity and most diverse distribution of peaks. The solvents tested include different mixtures of water, methanol, acetonitrile, toluene, chloroform, and dichloromethane. The results show that many of these mixtures give similar spectra; however, more peaks in the higher mass range are observed with toluene, chloroform, and dichloromethane. To this point, the 50/50 water-methanol solvent mixture used for most EESI experiments gives the most reproducible, and significantly intense spectrum for the analysis of cellulose.
Advisor: Keith Burridge (Cell Biology and Physiology)
Abstract: I am investigating the mechanism by which the parasite Trypanosoma brucei crosses the microvascular endothelium of the blood-brain barrier (BBB) to cause Human African Trypanosomiasis. There are two stages of this disease: the acute stage is characterized by parasites confined to the blood and lymph, whereas the chronic stage is characterized by parasites aggregating in the brain parenchyma (Masocha et al., 2004). T. brucei crossing the BBB facilitates pathogenesis, disrupting circadian rhythms of sleep and is potentially fatal (CDC). While the acute stage can be treated with chemotherapy, deficient treatment for the chronic stage calls for a better understanding of how T. brucei crosses the BBB. Some studies have shed light on this mechanism, but it is not yet truly understood. In a mouse model, Mulenga et al. (2001) observed that T. brucei is able to cross the BBB without compromising endothelial tight junctions. Tight junctions exist between adjacent endothelial cells to prevent unwanted cells from passing through the BBB. In another study using mice, T. brucei has been shown to cross the BBB at the same location as lymphocytes, implying that T. brucei may employ a similar mechanism as lymphocytes use to cross during an immune response (Masocha et al., 2004). I am using immunofluorescence microscopy to observe T. brucei interactions with an endothelial monolayer in vitro, with the aim of assessing localized changes in junction proteins and cytoskeletal actin patterns.
Advisor: Jason Arnold (Medicine)
Abstract: Probiotics are live microorganisms which, when administered in adequate amounts confer a health benefit to the host. Intraspecies variability accounts for a large percentage of the diversity within microbial communities. Moreover, variability at the strain-level can result in differences in probiotic potential between isolates of the same species. Lactobacillus rhamnosus GG, a well-known probiotic, provides significant benefits, including immunomodulation and pathogen exclusion. Other strains of L. rhamnosus have also demonstrated capabilities of free radical scavenging. Accumulation of free radicals has been associated with various diseases. In this study, we investigated the antioxidant activity of our novel human isolates of L. rhamnosus, AMC010 and AMC143, compared to well characterized strains, HN001, LC705, and GG, and wild-type strains of Escherichia coli and Enterococcus faecalis. Antioxidant activity was measured using spectrophotometric analysis of 2,2-diphenyl-1-picrylhydrazyl (DPPH), a free radical compound that absorbs light at 517 nm until reduced, making it a useful compound to assess antioxidant activity. All tested strains exhibited variable antioxidant activities. LC705 exhibited greater antioxidant activity when compared to other strains, suggesting that the strain may generate more antioxidant compounds. No differences were identified between live and heat killed bacteria, suggesting that the antioxidant molecule is heat stable.
Advisor: Aysenil Belger (Psychiatry)
Abstract: Emotional regulation is a fundamental aspect of adaptive behavior that is often disrupted in patients with post-traumatic stress disorder (PTSD). The goal of the present study was to examine the neural correlates of social emotional processing in PTSD and their association with PTSD symptom severity.
Methods: 100 veterans with PTSD and 20 healthy controls without PTSD or military history underwent functional magnetic resonance imaging (fMRI) while completing an emotional face-matching task. Additionally, subjects completed the Clinician Administered PTSD Scale (CAPS), Barratt Impulsiveness Scale (BIS), and DKEFS Color-Word interference tasks. I hypothesized that the PTSD group would show greater emotional reactivity compared to control subjects in that veterans would show greater amygdala and limbic and less medial frontal cortex (mFC) activity. I further hypothesized that hyperarousal of the amygdala in the PTSD group would be associated with greater CAPS, BIS, and lower DKEFS Color-Word interference scores.
Results: Veterans demonstrated greater mFC and posterior temporal fusiform cortex (ptFC) activity than controls during faces, and greater mFC, ptFC, and orbito-frontal cortex (OFC) activity than controls in the shapes block. No differences were found in amygdala activation or error rates. There were many significant correlations between regional brain activation and clinical measures, notably, between the right amygdala and total CAPS scores.
Conclusion: Hyperarousal of the mFC and OFC in PTSD suggests a compensatory mechanism of affective regulation. Deficits in several regions correspond to more severe PTSD symptoms, indicating that these regions may be instrumental in emotional regulation. Increased activation to shapes corresponds to increased PTSD symptoms, suggesting that inappropriate limbic activation is associated with PTSD symptoms. Future research should explore white matter connectivity and volumetric differences, and how they relate to PTSD symptomatology, in order to develop more targeted interventions against PTSD.
Advisor: Sean Washburn (Physics & Astronomy)
Abstract: Diabetes currently affects over 422 million people globally. These patients are forced to regularly monitor their blood glucose level by pricking their finger multiple times a day, increasing their likelihood to bruising and infection. This project aims to find an alternative method to monitor blood sugar that is noninvasive using a combination of photoplethysmography and near infrared light. Previous studies have discovered a correlation between the peak value of the photoplethysmogram using a pulse oximeter and the concentration of glucose in a patient's blood. The components of this investigation include an Arduino microcontroller board, a pulse oximeter, and a computer with the Arduino program. Ultimately, a patient should be able to place their finger into a pulse oximeter and determine their glucose level based on the relationship discovered in this study and previous ones alike.
Advisor: Keely Muscatell (Psychology and Neuroscience)
Abstract: Stress is important to study because of the abundance of stressors and the potential impact it has on health. The impact of stress can vary based on the cognitive appraisal of the stressor. Lazarus and Folkman (1984) define cognitive appraisals as the process of interpreting an event and its different features, with respect to its impact on the individual. Cognitive appraisals consist of two types of appraisals: challenge and threat, which are associated with different affective outcomes. The main purpose of this study is to see if blocking sympathetic nervous system activity influences the types of cognitive appraisals made in the face of a stressor. The SNS is specifically examined because it plays a major role in physiological arousal. The SNS was suppressed via the beta-blocker propranolol to test whether participants who received the drug would have higher challenge appraisals. Participants were randomly assigned to either a placebo group or beta-blocker group, and both groups later completed the Trier Social Stress Test. An affect measure (PANAS) associated with performance on the TSST was given pre-and-post TSST. The main hypothesis that individuals in the propranolol condition will make higher challenge appraisals and lower threat appraisals than those in the placebo condition was not supported. However, propranolol did have an impact on affective differences between groups. Individuals in the propranolol condition had lower negative affect pre-stress and post-stress compared to the placebo. These findings are discussed in the context of health and depression.
Advisor: Johna Register-Mihalik (Exercise and Sports Science )
Abstract: As the multimodal approach to concussion assessment continues to develop, more time and attention are needed to complete a comprehensive assessment. This study is necessary to understand recreational athletes' perceptions of the concussion assessment battery (CAB) in order to inform use and interpretation of clinical results. All participants (Females=25; Males=5; ages 18-25) completed a comprehensive CAB including an assessment of symptoms, neurocognition, visual/vestibular function, and balance. Participants then completed a CAB opinion survey. Descriptive statistics were utilized to describe athlete perceptions. Overall, 66.7% (20/30) agreed that the battery was easy. Additionally, there was a significant, but weak correlation (r= -0.28, p=0.03) between total attitude score (TAS) and visual memory, such that the more positive a person's attitudes toward the overall battery, the worse their visual memory for geometric shapes. This work highlights that positive perceptions and attitudes toward the CAB do not always correlate with positive performance, and indicates that perceptions of and attitudes toward the CAB may not matter for success on the test. Therefore, it may not be clinically effective to change their perceptions to improve baseline performance. Future work should investigate factors that may influence performance and administration as well as how these factors may change post-concussion.
Advisor: Jonathan Abramowitz (Psychology and Neuroscience)
Abstract: The research reported here was designed to expand upon the understanding that cognitive and metacognitive theories offer explanations for the development of obsessive compulsive disorder (OCD) by contrasting predictions derived from these models. The Obsessive Beliefs Questionnaire (OBQ-44) was used to measure beliefs considered to be critical to the etiology of OCD from the cognitive perspective. The Metacognitive Beliefs Questionnaire (MCQ-30) was used to measure beliefs related to monitoring and evaluating thoughts. Each of these models has support in that both cognitive and metacognitive beliefs are linked to OC symptoms, but the extent to which the OBQ and MCQ account for various obsessive-compulsive (OC) symptoms has not yet been compared. Partial correlations and hierarchical regression analyses provided a framework through which to compare the utility of these tools in predicting OC symptoms, while holding general distress constant. The OBQ significantly predicted OC symptoms related to responsibility for harm and unacceptable thoughts, whereas the MCQ significantly predicted OC symptoms related to unacceptable thoughts and symmetry. Neither the OBQ nor the MCQ significantly predicted OC contamination concerns, however, across regression models the MCQ and OBQ did differ in the amount of variance in OC symptoms that they could each explain. This study offers additional insight into how cognitive and metacognitive models align with various OC symptom domains.
Advisor: Saskia Neher (Biochemistry and Biophysics)
Abstract: Proper functioning of many human lipases requires assistance from the protein Lipase Maturation Factor 1 (LMF1). The exact mechanism by which LMF1 functions is still under study, and LMF1 is also found in cells and organisms that do not secrete lipases, suggesting it has additional, unknown functions. Because no LMF1 homologs have known structures, resolving the structure of any protein in LMF1's family will offer insight into how this important protein works, as function can be inferred from structure. Homologs from Acidothermus cellulolyticus and Streptomyces avermitilis bacteria, both 40% identical to human LMF1, will be studied. Their expression was optimized by testing a variety of cell lines and growth conditions. Protein purification strategies using a variety of detergents and nickel-NTA columns were developed and binding, wash, and elution buffers optimized. Subsequent work will involve characterizing the three dimensional structures of the homologs using macromolecular crystallography.
Advisor: Greg Matera (Biology )
Abstract: MicroRNAs (miRNAs), a class of noncoding RNAs, have been examined as potential regulators of cancer cell progression and metastasis pathways. miRNAs bind to mRNA transcripts and target them for degradation or translational inhibition. The goal of this project was to develop tools to study miRNA function. miR-124 has been known to reduce the proliferation of the breast cancer cell, MCF-7. It is also the most abundantly expressed miRNA in neuronal cells. In this project, we used tRNA processing to generate tRNA intronic circular (tric)RNAs, which will serve as an exogenously expressed miRNA sponge. This sponge construct contains four mir-124 binding sites and will compete with endogenous targets for miR-124 binding, ultimately affecting the targets? regulation. Due to the stability of circular RNAs, we hypothesized that it would make a superior sponge to its linear RNA counterpart. The miR-124 sponge was transfected into HEK293T cells and the RT-PCR assay showed that the sponge was being expressed. The next step would be to conduct a cell growth assay to assess the growth profiles of miR-124 inhibited cells, and to assess changes in target expression profiles using RT-PCR and Western Blotting.
Advisor: Cathi Propper (Psychology)
Faculty/Postdoc Contributors: Cathi Propper
Abstract: Westernized societies generally believe bed-sharing negatively impacts a child's autonomy and independence. However, one study found that parent-child bed-sharing may protect against attachment insecurity. Thus, the current study assesses the relationship between bed-sharing and infant behavior during the Still-Face Paradigm (SFP), an early assessment of parent-child relationship quality. The sample consists of 50 African-American mother-infant pairs classified via observational data as bed-sharing (BS; n = 31) or solitary sleeping (SS; n = 19). Dyads within the bed-sharing group were also classified as proactively bed-sharing (PBS; n = 20) or reactively bed-sharing (RBS; n = 11). At 6 months of age, the SFP was conducted, filmed, and coded. Based off previous literature linking SFP responses with attachment security, we hypothesized that less negativity, more positivity, more gazes towards mother, and more self-regulatory behaviors would be observed in the BS infants, especially the PBS infants. Results indicated that SS infants displayed more negative affective expressions and negative vocalizations during the SFP, while BS infants displayed more self-regulatory behaviors. Additionally, PBS infants displayed more gazes towards mother during the SFP than RBS infants. These findings suggest that infant behaviors during the SFP vary based on early nighttime experiences, with bed-sharing, particularly proactive bed-sharing, potentially promoting the parent-child relationship.
Advisor: Jason Franz (Biomedical Engineering)
Abstract: The Achilles Tendon (AT) is a part of a human's musculoskeletal system that plays a role in the movement of the ankle and thus serves a function in locomotion. One measure of the effectiveness of the AT in force output is the AT moment arm. The AT moment arm is the distance from the line of action of the AT force and the center of rotation of the ankle joint. During the push-off phase of walking, the AT moment arm increases, although the mechanisms responsible for this change are poorly understood. Previous studies have only used isolated ankle exercises to quantify the AT moment arm, which may not represent dynamic movements. However, there is evidence suggesting that the AT moment arm exhibits complex behavior that is dependent both on ankle joint kinematics and dynamic muscle loading during movement. In addition, evidence suggests that the AT moment arm also varies between older and younger individuals. During these sets of experiments, we sought to investigate the mechanisms underlying this complex behavior by coupling quantitative motion analysis and dynamic ultrasound imaging of the AT and calf muscles. We hypothesize that the AT moment arm varies significantly due to muscle loading, governed by bulging during force generation, which is compromised by musculoskeletal changes due to aging effects. In order to investigate what causes AT moment arm to vary during isolated ankle exercises, three specific measurements were made using a Biodex machine.
Advisor: Darin Padua (EXSS)
Abstract: Background: Female athletes generally experience higher rates of noncontact ACL injury than men. Females typically have less lower extremity lean mass than men and experience more frontal plane knee motion, both of which may contribute to ACL injury. Aim: Investigate the association between lower extremity lean mass and changes in neuromuscular control of the hip and knee during jump landing in response to an acute High Training Load (HTL) in college-aged female athletes. Methods: 43 physically active college-aged females were enrolled in this study. Participant's lower extremity and lumbo-pelvic hip complex (LPHC) mass composition were measured using dual-energy x-ray absorptiometry (DXA) and were normalized to total body mass. Net internal sagittal and frontal plane hip moments during a jump-landing task were measured before and after a controlled HTL exposure. Pearson-product moment coefficients were calculated between body composition and hip moments. Results: There were significant correlations between the change in frontal plane hip moment (hip adduction moment) and subtotal lean mass normalized to body (r=0.315, p<0.05) and change in sagittal plane hip moment (hip extension moment) with Lumbo-Pelvic Hip Complex (LPHC) lean mass (r=0.326, p<0.05). Discussion: Individuals with greater LPHC lean mass appear to have a greater capacity to manage sagittal plane energy absorption at the hip following exposure to HTL.
Advisor: Donaldson Conserve (University of North Carolina at Chapel Hill Gillings School of Public Health (Health Behaviors))
Undergraduate Co-Authors: Allison Heather Gray; Matthew Louis Gilleskie
Abstract: Background:While African Americans represent 13% of the U.S. population, they constitute 44% of those newly infected and 43% of those living with HIV.Studies show a strong association between depression, medication non-adherence, risky sexual and substance use behaviors, and increased morbidity and mortality. Objective:To systematically review treatment interventions aimed at improving depression and HIV+ related outcomes among African Americans. Method:We searched PubMed, Web of Science, and PsycInfo to identify peer-reviewed studies from 2010-2016. The search terms included African Americans, HIV, and depression. Eligibility criteria will include: interventions designed to address depression among Blacks/African Americans living with HIV; publications that report depression treatment and health outcome effects; and published in English in a peer-reviewed journal. Result:Our search yielded 404 articles. Two authors will independently screen the search output, select studies, and extract data, resolving discrepancies by consensus and discussion. Cochrane risk of bias tools will be used to assess study quality, and additional studies will be identified by searching references of systematic reviews and reports. Discussion:Findings will provide guidance on the success of existing interventions and future research areas on depression among African Americans living with HIV.Given the associations between depression and poor HIV-related outcomes,more research is needed.
Advisor: Cathi Propper (Center for Developmental Science )
Abstract: Mothers with higher levels of depression and anxiety tend to report more sleep problems in their infants than mothers with lower levels of depression and anxiety. One mechanism by which maternal distress (i.e., depression and anxiety) could affect infant sleep outcomes is through the actions the mother performs as she readies her infant for nighttime sleep, referred to as maternal bedtime practices. Emerging literature links maternal distress with the practice of putting infants down for bed asleep, as well as greater amounts of close contact and directly arousing activities during the bedtime period. The interplay between maternal distress and bedtime practices has primarily been studied in Caucasian populations, even though African American children show worse sleep outcomes and are more likely to have mothers with depression. This study aims to examine the relationships between maternal distress (measured via self-report questionnaire), bedtime practices (coded from a video of the infant's bedtime), and infant sleep outcomes (determined by actigraphy), in an African American population. Findings indicate that higher maternal distress at 3 months predicts a use of directly arousing activities at 3 months, and that putting the infant down to bed awake more often at 3 months predicts better sleep outcomes at 6 months. This study supports and extends the current literature by demonstrating that maternal distress and bedtime practices play a role in infant sleep quality in African American populations.
Advisor: Johna K. Register-Mihalik (EXSS)
Graduate Student Contributors: Melissa C. Kay
Faculty/Postdoc Contributors: Johna K. Register-Mihalik
Abstract: Sport played as well as the location of impact of a concussion are common ways of describing a potential injury. By examining sport, location of impact, and resulting symptomology, medical staff have a more complete picture of the injury occurring. Studies have linked injuries to certain parts of the brain with a common group of symptoms. Therefore, the purpose of this abstract was to examine the influence of sport and location of impact on symptom, visual, and neurocognitive outcome measures acutely following concussion in adolescent student-athletes reporting to a family practice clinic. 306 subjects with concussive symptoms (n=181 males, n=123 females) underwent a standardized initial concussion assessment battery that included the following: vision, neurocognitive measures, and injury demographics (including mechanism of injury, location of impact, and sport). Mean participant age was 14 ?? 2.1 years old (min=8, max=18). Two sample T-tests (contact or non-contact sport) were run for each outcome (symptom total, Near Point Convergence average, ImPACT domains: Verbal and Visual Memory, Processing Speed, and Reaction Time). One-way ANOVAs were run to determine location of impact influence on each outcome. Outcomes did not differ by sport-type or location of impact (p>0.05). These data suggest that acute symptom, visual, and/or neurocognitive outcomes do not differ by sport or location of impact. Future research should examine how these factors are associated with recovery.
Advisor: Brian Pietrosimone (EXSS)
Abstract: Knee osteoarthritis (KOA) is the 11th leading cause of disability worldwide. A previous knee injury increases the risk of developing knee OA; approximately one third of individuals who sustain an anterior cruciate ligament (ACL) injury, and subsequently undergo an ACL reconstruction will develop KOA within ten years. There are many possible causes leading to the development of KOA following ACL reconstruction, including damage or inflammation to the infrapatellar fat pad (IFP). The IFP is a highly innervated and vascularized structure, primarily composed of adipose tissue, located in the anterior compartment of the knee. Although exact function of the IFP has yet to be characterized, it is known to assist in the biomechanics of the lower limb and contains a store of reparative cells following a knee injury. In addition, the inflammatory response that occurs in the IFP may aid in the development of KOA. This project will use magnetic resonance imaging to visualize and measure the volume of the IFP in patients that have sustained an ACL injury and have undergone ACL reconstruction. In order to quantify patient reported knee symptoms, the Knee Injury and Osteoarthritis Outcome Score (KOOS) will be used. The goal of this project is to determine the association between infrapatellar fat pad volume and patient reported outcomes 12 months following ACL reconstruction. We hypothesize that individuals with larger IFP, indicating more synovitis, will demonstrate worse KOOS.
Advisor: Melissa Munn-Chernoff (Psychiatry)
Abstract: Research has identified a group of individuals who purposely change their eating behaviors prior to alcohol consumption to save on calories or get drunk faster (in lay terms, "drunkorexia"). However, studies have not adequately characterized these individuals. This study aims to examine differences in demographic and psychological traits (e.g., sex, disordered eating) between individuals who do and do not report drunkorexia. Participants included 250 students (age range=18-25 yrs; 60.80% females) recruited from a psychology subject pool. Questions about changing eating behaviors prior to alcohol consumption, and reasons for these changes, were assessed via an online survey. We used descriptive statistics to investigate differences in these traits between students who reported drunkorexia vs. those who did not. Forty-seven (18.80%; n=31 [67.65%] female) individuals reported drunkorexia. Of these 47 individuals, 34 (72.34%) restricted their food intake prior to drinking to get drunk faster and 31 (65.96%) did so to prevent weight gain; 18 (38.30%) indicated both reasons. More females (n=23, 48.94%) than males (n=11, 23.40%) engaged in drunkorexia to get drunk faster. Similarly, more females (n=22, 46.81%) than males (n=9, 19.15%) engaged in drunkorexia to prevent weight gain. Drunkorexia is present among college students. Subsequent analyses will evaluate differences on additional demographic and psychological traits between individuals who do vs. do not report drunkorexia.
Advisor: Tamera Coyne-Beasley (Pediatrics- School of Medicine )
Graduate Student Contributors: Marni Krehnbrink
Abstract: Title: Race, Place, and Depression: How are adolescent demographics related to depression in North Carolina? Question: Is adolescent depressive symptom severity associated with gender, race, socioeconomic status and city? Background: Suicide is the second leading cause of death for adolescents aged 10-24 in the United States; injuries due to self-harm for those ages 15-19 are higher than in any other age group. Both suicide and self-harm are preventable and associated with depression. Depression in adolescents and young adults is underdiagnosed and undertreated. Intersectionality in race, gender, place, and socio-economic status create multidimensional and interplaying layers of disadvantage that may impact depression severity. Design/Methods: Data were obtained from patients, ages 11-21 at a pediatric clinic from 2012-2016. Demographics were abstracted through electronic medical records. A modified Guidelines for Adolescent Preventative Services survey was used to collect data on behaviors. PHQ9 was used to screen for depression; a score of ?11 indicated a positive screen. Insurance was used as a proxy for socioeconomic status. It was measured through record of public vs private vs no insurance for each patient (coded as 0, 1, 2). Sample characteristics were assessed with univariate analysis. Bi-variate chi-square analyses were then utilized to assess associations of depression with demographics and potentially protective behaviors; multivariate logistical regression assessed global associations between depression, demographics, and categorical risk taking behaviors to calculate odds ratios for depression. Results: 839 adolescents participated in the study, 48.8% male and 51.2% female. Participants were distributed with the following percentages: 18.4% white; 42.0% black; 31.0% Hispanic. About 12.21% were uninsured and 66.71% were publically insured. The mean age was 14.0 years. 11.32% screened positive for depression. Depression was significantly positively correlated with being female (OR=2.26, p=0.041), Hispanic (OR=2.92, p=0.045), and on public insurance (69.39% of 11+, p=.841). There is a statistically significant relationship between insurance status and geographic location (p=.031); more adolescents screened positive for depression (score 11+) category who are from Chapel Hill and Durham (24.49% and 28.57% respectively) (p=.85), than other locations (Raleigh, Hillsborough, and Burlington). Conclusion: In the sample of 839 adolescents, females, people of Hispanic origin, uninsured/publically insured individuals, and those in Durham, NC and Chapel Hill, NC were the most likely to report depressive symptoms. Hispanic publically insured females were the most likely to have the highest PHQ9 scores. These findings call for an increase in attention to adolescent groups that experience multiple facets of disadvantage and depression.
Advisor: Melinda Beck (Nutrition - Gillings School of Global Public Health)
Abstract: Post-menopausal women are known to have a decline in health due to numerous factors, including a decrease in estrogen production and levels in the body. Older women are also known to be more susceptible to various diseases. In this study, post-menopausal women's antibody response to the flu vaccine is analyzed to see if there is a correlation between the strength of their antibody response and their respective serum estrogen levels.
Advisor: Brian Pietrosimone (Exercise and Sports Science)
Abstract: Femoral cartilage deformation following acute loading is dependent on cartilage composition. This study was conducted to determine the magnitude of medial, lateral and intercondylar femoral cartilage thickness deformation following drop landings using diagnostic ultrasonography (US) in healthy individuals. 35 healthy volunteers with no history of knee injuries participated in this study. Medial, lateral and intercondylar femoral cartilage thickness was measured using US imaging before and after drop landings. Each participant completed 120 drop landings from a 62 centimeter box within approximately 45 minutes. Cartilage deformation was calculated as the percent change in thickness from pre to post drop landings in each compartment. Separate independent t-tests were used to compare pre and post thickness measurements. There was a significant deformation in cartilage thickness in the medial (P<0.001, pre=2.39mm, post=2.19mm, %Δ=-8.7%) and lateral (P<0.001, pre=2.31mm, post=2.16mm, %Δ=-6.4%) compartments of the knee when comparing pre and post drop landing thickness values, but the intercondylar compartment deformation was not statistically significant (P= 0.135, pre=2.30mm, post=2.25mm, %Δ=-1.3%). This study demonstrates how healthy cartilage deforms following a high magnitude loading task such as drop landings, which may allow for future studies to identify individuals who respond negatively to loading which may indicate early decline of cartilage health.
Advisor: Yuliya Pylayeva-Gupta (Department of Genetics)
Faculty/Postdoc Contributors: Nancy Kren, Yuliya Pylayeva-Gupta
Abstract: Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy with a consistently poor prognosis (with a <7% five-year survival rate). Oncogenic KRAS is the primary driver of PDAC, and has been previously shown to upregulate GM-CSF, a cytokine, contributing to a pro-tumorigenic, immunosuppressive microenvironment. Additionally, exosome secretion requiring Rab27a can also initiate formation of a pre-metastatic niche in organs distant to the pancreas (lungs and liver), priming them for tumor growth through similar immunosuppressive mechanisms. This project aims to see if the silencing of either GM-CSF, Rab27a, or both can slow tumor growth, dampen the recruitment of immunosuppressive cells in the pancreas and distant organs, and reduce metastatic potential in PDAC. This could identify Rab27a and GM-CSF as potential targets for therapeutics, especially immunotherapy.
Advisor: Mark Peifer (Biology)
Abstract: Coordinated cell adhesion and actin remodeling are required for normal development and tissue homeostasis. Regulatory proteins like Abelson tyrosine kinase (Abl) are essential for this coordination. Abl is a highly conserved, multi-domain protein, with a kinase domain, F-actin binding domain, and domains involved in assembly of signaling complexes. While the role of Abl's kinase activity is well understood during development and disease, such as Leukemia, the role of other domains remains largely unexplored. We began by dissecting the roles of different Abl functional domains during embryonic morphogenesis, using a fruit fly model. Surprisingly, a short, conserved motif (PXXP) in the linker region of Abl is more critical for morphogenesis than both kinase activity and F-actin binding. In mammals, this motif is a binding site for three SH3-domain proteins: Abi, Crk, and Nck. We find knockdown of Crk and Abi, but not Nck, produces phenotypes mimicking that of mutants lacking Abl or Abl's PXXP motif. I am following this by characterizing how loss of Crk disrupts embryonic morphogenesis and how varying Crk levels modifies abl mutant phenotypes, to reveal how Crk and Abl regulate morphogenesis both together and independently. To do so, we generated a crk mutant using CRISPR, and are characterizing phenotypes caused by loss of Crk, to determine Crk's role during processes that require coordination of cell adhesion and the cytoskeleton, including cellularization and CNS patterning.
Advisor: Greg Lewis (Psychiatry)
Abstract: The polyvagal theory explains how neural regulation of the heart through the vagus nerve can influence a child's psychological state and social interactions through either dysregulation or regulation of the heart by brain systems. Children who have dysregulation are at a higher risk of anxiety, depression, aggression, and other social problems. Premature birth is a risk factor for dysregulation, as completion of the myelination process for the vagus has not been achieved. ECG data from premature infants was obtained from the NICU at Columbia University. ECG data was processed through a combination of automated and visualized procedures to identify the peak of the R-waves. From there the interbeat intervals (IBIs) were extracted between each R-wave to reveal the respiratory sinus arrhythmia (RSA) of the infant. It was found that there was a positive correlation between mean IBI and RSA. The influence of sleep state (active and quiet sleep) on the coupling of RSA and mean IBIs was explored in the premature newborns. Sleep serves as a bidirectional interaction between the brain and the body. The physiological differences that occur between the two sleep states reveal the individual differences in the efficiency of the autonomic nervous system (ANS). It was found that regulation of the vagus nerve changes as a function of sleep state, revealing a difference in the function of the ANS and a measure of the functionality of the brain-vagus-heart regulatory system.
Advisor: Rita Tamayo (Department of Microbiology and Immunology)
Faculty/Postdoc Contributors: Danielle Fortune, Ph.D.
Abstract: The intestinal pathogenic bacterium, Clostridium difficile is a Gram-positive, spore-forming, obligate anaerobe. It is currently classified as an urgent public health threat and is a major cause of fatal nosocomial infections in the United States. Due to the high recurrence of C. difficile in previously infected patients, C. difficile virulence factors have become especially important to study. Literature suggests the bacterial second messenger, c-di-AMP is important in controlling sporulation in Bacillus subtilis. Because B. subtilis shares many similarities with C. difficile, we hypothesize that c-di-AMP may play a role in multiple important cellular processes such as sporulation efficiency in C. difficile. There are two diadenylate cyclases, DisA and DacA, and one phosphodiesterase, YybT, identified in C. difficile that are orthologs to c-di-AMP controlling proteins in B. subtilis. In order to examine the function of diadenylate cyclases, we expressed disA and dacA in E. coli through the use of an inducible expression system. Specifically, we cloned and expressed disA and dacA into an IPTG-inducible His-tagged expression vector. This resulted in a recombinant protein with a 6xHis fused to its N-terminus. We determined that the proteins were soluble and performed a small-scale purification using affinity purification. Future studies include using the resulting proteins for in vitro biochemical assays. Additionally, we aim to establish that DisA and DacA are functional diadenylate cyclases as well as identifying the biological significance of these proteins.
Advisor: Gabriel Dichter (Psychiatry; Psychology and Neuroscience; Carolina Institute for Developmental Disabilities)
Abstract: Background: To evaluate response to treatment in autism spectrum disorder (ASD), a robust measure is needed to compare an individual's social communication ability before and after social skills treatment.
Objectives: This project aims to evaluate whether a dynamic eyetracking (ET) paradigm may be used as a sensitive measure of treatment response in ASD.
Methods: 18 participants with ASD were recruited for an 8-week social skills group (SCIT-A) and 23 continued treatment as usual (TAU). SCIT-A participants completed the ET task before and after the social skills group and TAU visits were separated by 8 weeks. The ET task showed participants' visual preference for social stimuli and this was compared to existing measures of social communication. 22 control participants were recruited to determine test-retest reliability of the ET paradigm.
Results: Analyses of the social prioritization ET measure indicate good test-retest reliability (α=0.86; ICC=0.80, 95% CI [0.35, 0.93]). Controlling for visit, IQ, and group, none of the existing measures of social communication were significant predictors of the ET metric across visits.
Conclusion: The social prioritization ET score is reliable but it does not show significant relationships with currently used measures of social communication. The high quality of clinical care for TAU participants may make this comparison group too stringent to find a between-groups effect or this ET measure may simply not be sensitive to change over time.
Advisor: Amy Weil (Internal Medicine)
Undergraduate Co-Authors: None
Graduate Student Contributors: Jamie Jarmul, Margot Hedlin
Faculty/Postdoc Contributors: Amy Weil, Darren DeWalt
Abstract: Objective: The objective of this pilot study was to collect preliminary data on screening for health literacy in an inpatient setting, as well as patient-reported data on physician communication, scheduling of follow-up appointments, and quality of discharge instructions. Measures: Convenience sample of admitted medical patients categorized as either moderate or high risk of readmission. Health literacy was assessed using the Newest Vital Sign (NVS); quality of patient-provider communication was assessed using the Health Communication Assessment Tool (HCAT). We collected qualitative data on quality of discharge instructions and follow-up appointments through in-person and phone interviews. Patients were approached and consented when chart review indicated that they were within 1 day of discharge. Results: Enrollment of 10 patients in this pilot study; 8/10 patients had limited literacy. The mean of all HCAT questions was ??? 4.4, indicating that patients generally felt communication with their physicians during hospitalization was excellent. While the 8/10 patients felt prepared for discharge, 4/10 had not discussed follow-up plans with their physicians and 8/10 did not have a follow-up appointment scheduled when interviewed less than 24 hours before hospital discharge. We were able to contact 6 /10 patients for the follow-up phone interview; 4/6 were able to recall the primary diagnosis from their hospitalization and 3/6 had received written information about "red flags".
Advisor: Simon Meek (Chemistry)
Faculty/Postdoc Contributors: Michael Liang
Abstract: Methods of making stereodefined secondary alcohols are important in the synthesis of biologically relevant compounds. This project explores the formation of such an alcohol adjacent to a vinyl boronate ester from the deprotonation of diborylmethane and subsequent reaction with a stereodefined epoxide in the presence of a palladium catalyst. The products are afforded in good yield and high E:Z selectivity (>20:1). HPLC traces using pure and racemic starting material provide evidence of the mechanism proceeding without the erosion of enantioselectivity. The substrate scope explored a range of readily available aryl epoxides. This approach allows for further functionalization due to the versatility of boron in transformations into more useful products.
Advisor: Kristen Kucera (Exercise and Sport Science)
Abstract: Gymnasts execute complex and highflying feats that create unique circumstances that may put them at risk of sustaining catastrophic injuries. According to the National Center for Catastrophic Sport Injury Research (NCCSIR), male gymnastics had one of the highest direct catastrophic injury rates per 100,000 participants, ranking among sports like football and ice hockey. The purpose of this study is to describe the events, activities, and mechanisms behind catastrophic sport-related injury in high school and college level gymnastics. Cases were found using the NCCSIR surveillance system and included catastrophic sport related injuries among high school and college level gymnasts from 1982 to 2015 (n=31). A detailed review will determine injury characteristics including: event being executed (vault, beam, floor, etc.); activity leading to the injury (rotation, approach, landing, etc.); and mechanism of the injury (contact with matt, contact with vault, etc.). Results from this study will expand insight into the circumstances surrounding catastrophic injuries in gymnastics and inform future research and prevention measures focused on activities and mechanisms of greatest concern.
Advisor: Elizabeth Mayer-Davis (Nutrition )
Abstract: Background and Objectives: An effective strategy for type-1 diabetes self-management includes strategic planning of dietary intake and adjustment of insulin dosing, which requires educating patients about food composition and meal planning strategies to help maintain blood glucose levels. However, despite the availability of nutrition education materials for patients with T1D in Western regions, no educational meal planning materials are available for T1D patients living in China. The objective of this study was to investigate the facilitators and barriers to meal planning strategies among type-1 diabetes patients in Beijing, China. Methods and Study Design: Two online nutrition surveys were developed through Qualtrics Survey Software: one survey was created for T1D patients (n=100) and one survey was created for providers (n=11) from the Peking University People's Hospital in Beijing, China. Patients interested in participating were recruited through an online community and given a personal link to complete the survey. Providers were given an anonymous link sent by email by a collaborator of the project who is also an endocrinologist from the Peking Hospital (Dr. Wei Liu). While results are still currently being finalized (and will be fully ready by presentation day), data collected have so far suggested limited nutrition knowledge as a possible barrier to proper self-management of type-1 diabetes with dietary intake.
Advisor: Troy Blackburn (Exercise and Sports Science )
Abstract: Anterior cruciate ligament injury and surgical reconstruction (ACLR) incur a high risk of knee osteoarthritis (OA). While simultaneous activity of the quadriceps and hamstring muscles is required for normal walking gait, excessive co-activation may lead to altered biomechanics that contribute to OA development. Therefore, the purpose of this study was to evaluate relationships between quadriceps/hamstrings co-activation and gait biomechanics linked to knee OA development in individuals with ACLR. Walking gait biomechanics and electromyography of the quadriceps and hamstrings muscles were assessed in 26 individuals with ACLR. Quadriceps/hamstrings co-activation index, peak vertical ground reaction force (vGRF) magnitude and loading rate, and knee joint kinematics and moments were calculated during the preparatory and load acceptance phases of gait. The co-activation index was not correlated with vGRF characteristics. However, greater preparatory co-activation was associated with greater knee varus moment (r= 0.398, p = 0.046) and greater load acceptance co-activation was associated with greater knee varus moment (r = 0.392, p = 0.049) and peak knee varus angle (r = 0.404, p = 0.043). The varus motion and moment apply compressive force to the cartilage in the medial knee compartment where knee OA is more prevalent. As such, the results of this investigation suggest that greater quadriceps/hamstrings co-activation may play contribute to the mechanical pathogenesis of PTOA.
Advisor: J. Troy Blackburn (Exercise and Sport Science)
Faculty/Postdoc Contributors: Dr. Brian Pietrosimone
Abstract: Anterior cruciate ligament (ACL) injury and surgical reconstruction (ACLR) increase the risk of knee osteoarthritis (OA). Heightened loading rates have been observed following ACLR and are associated with greater cartilage damage in animal models. ACLR individuals also demonstrate somatosensory deficits that may contribute to higher loading rates. However, the relationship between somatosensory function and gait biomechanics has yet to be evaluated post-ACLR. The purposes of this study were to 1) compare joint position sense (JPS) and vibratory perception threshold (VPT) between the ACLR and contralateral limbs, 2) evaluate the relationship between JPS and VPT, and 3) evaluate the relationship between somatosensory function and loading rate during gait following ACLR. JPS, VPT, and gait biomechanics were assessed in 30 ACLR individuals. JPS was assessed as the ability to reproduce a specified joint angle. VPT was assessed as the minimum detectable vibration amplitude applied to bony prominences in the lower extremity. Loading rate was assessed from force plates embedded in a walkway as the peak of the 1st time derivative of the vertical ground reaction force (vGRF). No significant between-limb differences in JPS or VPT were observed, nor were any significant correlations between JPS and VPT or between vGRF loading rate and either JPS or VPT observed. These results suggest that current ACLR and rehabilitation sufficiently restores somatosensory function following rupture.
Advisor: Jason Mihalik (Exercise and Sports Science)
Faculty/Postdoc Contributors: Cassie Ford
Abstract: While athletic headgear can reduce the risk of catastrophic brain injury, little research has identified how different types affect an athlete's visual field. Vision is a key component of injury risk and performance, so understanding the effect of headgear on vision is critical for athletic safety and success. The purpose of this study is to determine if headgear affects visual and sensory performance in college-aged female lacrosse players. Twelve healthy female participants (age 20.6 ??0.9 yrs) completed ten assessments of visual and sensory performance on the Sensory Senaptec Station under three conditions: no headgear, full-helmet, and goggles. Testing was completed in one session, and condition order was randomized to minimize fatigue and learning effects. Results from the Senaptec tests were submitted to separate one-way repeated-measures ANOVAs with condition as the single factor. There was a significant effect of headgear on several of the sensory performance tests. In all cases, performance showed a decrement when participants were wearing goggles relative to no headgear; but there was no difference between goggles vs. helmet, or between helmet vs. no helmet. Additionally, there was no difference across conditions for the tests that measure visual performance. These results do not conclusively show that headgear diminishes performance; however, given that outcomes did decrease for some tests when goggles were present, they may not be the safest option.
Advisor: Cathi Propper (Psychology and Neuroscience)
Abstract: The current study examines associations between infant state, sleep quality, and future cognitive development. Differences in temperament and emotional reactivity may lead to changes in how children behave, learn, and interact with others. We see this early in life and it may already be affecting sleep quality, which may then lead to cognitive problems in later development. The sample consisted of 36 African-American mother-infant dyads. The current study hypotheses included (a) a negative correlation between distressed infant state and distressed infant vocalization with infant sleep duration; (b) a positive correlation between sleep duration at 3 months and cognition (assessed via the Bayley Scales of Development) at 6 months; and (c) a negative correlation between distressed infant state and vocalization at 3 months with 6 month cognition. Actigraphy was used to measure sleep quality, bedtime behavioral data were observed and coded to determine infant state, and the Bayley was administered to determine cognitive performance. No evidence was found for the hypothesized relationships in the current study, however we will present several potential limitations that may have contributed to these null findings. This project was made possible (in part) by support from the Office for Undergraduate Research at UNC-Chapel Hill.
Advisor: Darin Padua (Exercise and Sports Science)
Abstract: Background: An athlete's movement patterns directly influence the amount of stress placed on the body, therefore either increasing or decreasing injury risk. Purpose: The purpose of this study was to evaluate a link between biomechanics and physiological training load responses to high-intensity exercise (HIEE). Methods: Individuals were classified as "high injury risk" (LOW) and "low injury risk" (HIGH). Blood samples were collected pre and post-exercise. Serum cortisol, creatine kinase (CK-MM), and serum cartilage protein (sCOMP) were levels were evaluated using 2x2 mixed-model ANOVAs and 95% confidence intervals. Results: We observed a group-by-time interaction for CK-MM; LOW experienced a significantly greater increase (pre: 14.88 [7.62, 22.15] ng/ml, post: 20.14 [10.19, 30.09] ng/ml) in CK-MM when compared to HIGH (pre: 7.26 [6.64, 7.87] ng/ml, post: 7.73 [6.81,8.66] ng/ml). HIGH (205.08 [154.49, 255.68] ng/ml) exhibited significantly (F1,38=10.81, p<0.05) higher serum cortisol compared to LOW (128.92 [80.31, 177.53] ng/ml). Both groups experienced a significant increase (F1,39=4.39, p<0.05) in sCOMP in response to HIEE (pre: 457.04 [408.23, 505.84] ng/ml, post: 507.15 [451.90, 562.40] ng/ml). Conclusions: Individuals with HIGH exhibit higher overall stress levels (cortisol). Individuals with LOW load muscle tissue during exercise to a greater extent than individuals with HIGH, potentially offloading inert tissue that may not be resilient to higher mechanical stresses.
Advisor: Kristen Lindquist (Psychology & Neuroscience)
Faculty/Postdoc Contributors: Kristen Lindquist, Misha Becker
Abstract: Emotions are a part of everyday life however, how emotion language is understood and developed by children is an under researched area. According to linguistic research, syntactical bootstrapping is a domineering factor in a child's concept learning. Developmental research points to the importance of physical context in concept learning. From this stemmed two studies investigating the role of syntax and context in children's (3-5) ability to understand a novel word to be an emotion. Study 1, (N=114) children watched videos of puppets presenting a novel "alien" word in one of three syntactical structures (is, feels and feels about). After the video children completed a picture pointing task in which they could choose one of three images, either a state of being (cold), an action (running) or an emotion (surprised) to answer what the alien word meant. In study 2, (N=113) context was included in conjunction with the different syntactical structures. Children watched 7 videos, in each video an alien portrayed an emotional scenario. After each video the child again completed the same picture pointing task as in study 1. Preliminary results of a repeated measures ANOVA reveals significant 3-way interactions between age, syntactic structure and image choice, F(8, 414) = 2.07, p=.04, and between study, age, and image choice, F(4, 414) = 2.69, p=.03, suggest that emotion images are chosen consistently with age, syntactic structure, and that physical context increases emotion choices.
Advisor: Kristen Kucera (Exercise and Sport Science)
Abstract: According to the National Center on Catastrophic Sport Injury Research (NCCSIR), 66.5% of all direct catastrophic injuries among high school and collegiate female athletes from 1982-2013 are from cheer alone. NCCSIR relies on media monitoring and voluntary reporting which doesn't capture all events. Emergency department (ED) data can provide additional information about severe cheer injuries. This study will examine the epidemiology of severe cheerleading injuries seen in 100 U.S. hospital EDs between 2003-2015. The Consumer Product Safety Commission's National Electronic Injury Surveillance System (NEISS) database was utilized to examine severe cheerleading injuries seen in hospital EDs over the defined time period. There were a total of 250 severe injuries within this sample; with a national estimate of 4,777 total ED visits due to cheerleading injuries. Of these severe injuries, 70.8% required hospitalization, 18.4% were held for observation at the care center, and 10.8% were transferred. Additionally, 58.0% were among those ages of 12-16. The majority of cheerleading injuries (87.2%) occurred during school and extracurricular activities. Of the total injuries sustained, 52.4% were fractures, and 13.2% were concussions. According to this data, the injuries in cheerleading can be severe and justify surveillance and injury prevention measures.
Advisor: Scott Hammond (UNC-School of Medicine Cell Biology and Physiology)
Abstract: Dicer is a protein that broadly serves two functions: generates short non-coding RNAs (siRNAs and microRNAs), and recruit DNA damage response (DDR) factors for DNA repair. Human Dicer is a large multi domain protein about 200,000 Daltons in size 1. This protein serves a critical for RNA interference pathways; specifically for regulating post-transcriptional gene silencing. The protein synthesizes siRNAs and microRNAs by cleaving the precursors (dsRNA and pre-microRNA). The siRNA and microRNA then complementally bind to mRNA to alter translation or degrade mRNA all together. The Dicer protein also serves an important role in DNA damage response (DDR). Research shows that Dicer, Drosha, and ddRNAs are essential for recruiting DDR factors and amplify DDR signaling in response to the DNA damage The long-term goal of our research is to discover small molecules that inhibit Dicer protein translation, also determine molecules that alter Dicer's cleavage activity. By inhibiting Dicer, this will increase the spontaneous DNA damage in cancerous cells, which will reduce tumor growth and also increase the cell's sensitivity to chemotherapy drugs. However siRNA are not deliverable to the body and most of the tissues, making Dicer inhibition difficult. Therefore small molecules that alter Dicer's cleavage activity will be used to deliver to the body tissues. Using this strategy, the Dicer protein activity will be reduced and increase the cell's sensitivity to the chemotherapy drugs.
Advisor: Brian Pietrosimone (Exercise & Sport Science)
Abstract: Knee osteoarthritis is a costly condition that affects cartilage at the joint. Alterations in walking biomechanics are theorized as one cause of OA progression. Knee adduction moment (KAM) is interpreted as a measure of medial compartment load and is associated with OA progression. However, the association between KAM and acute cartilage deformation in healthy individuals remains unknown. Such research would provide valuable information regarding the healthy cartilage response to walking, which may help detect early declines in cartilage function in patients at risk for OA.??The purpose of this study was to determine the association between the magnitude of cartilage deformation immediately following walking and peak adduction moment (KAM) in healthy subjects. Healthy, active young adults participated in this study (n=37). Ultrasound imaging of femoral articular cartilage in the dominant limb was collected before and after walking on a treadmill for 5,000 steps. Walking biomechanics were determined in a motion capture laboratory. KAM was extracted for the dominant limb during the first 50% of the stance phase of gait. Pearson product-moment correlation (r) was used to determine the association between KAM and medial cartilage deformation.??There was no significant association between KAM and medial cartilage deformation after walking (r=0.181, p=0.285). More research is needed to determine which specific walking biomechanics are associated with cartilage deformation.
Advisor: Sarah Linnstaedt (Anesthesiology)
Abstract: Glucocorticoid receptor (GR) co-chaperone FKBP5 minor allele genetic variant rs3800373 predicts worse chronic posttraumatic pain (CPTP), and microRNA-320a directly regulates FKBP5 RNA and predicts CPTP in a stress-dependent manner. In this study we evaluated the hypothesis that rs3800373 alters miR-320a binding. Using a cohort of African Americans presenting to the emergency department after motor vehicle collision, we validated the association between rs3800373 and CPTP (n=907) used total RNA- and microRNA-seq data (n=96 and 172, respectively) to evaluate associations between FKBP5, GR, and miR-320a expression among individuals with and without the minor allele, and evaluated miR-320a/FKBP5 RNA binding in vitro and in vivo. Individuals with the rs3800373 minor allele experienced greater CPTP. In these individuals, FKBP5 and NR3C1 expression were highly correlated (r=0.67, p=9x10-6), suggesting glucocorticoid resistance, and, unlike those without the minor allele, no negative correlation between miR-320a and FKBP5 RNA was observed, suggesting escape from miR-320a regulation. Allele-specific miR-320a binding was supported by luciferase reporter assays, and in vivo SHAPE data suggested that differences in miR-320a binding are due to allele-specific changes in RNA secondary structure. The FKBP5 rs3800373 risk variant prevents stress-induced miR-320a downregulation of FKBP5, resulting in glucocorticoid resistance and increased vulnerability to chronic posttraumatic pain.
Advisor: Steven Buzinski (Psychology & Neuroscience)
Abstract: This research considers how goal progress and means set variability affect subsequent goal-congruent actions. People who have made little progress toward a goal are in a different psychological state than those who have made significant progress, causing different impacts of perceived means of goal attainment on goal pursuit. Therefore, we hypothesized that people with little goal progress would be motivated by a larger, more flexible array of means which should provide multiple opportunities for attainment. Conversely, people perceiving significant goal progress would be motivated by a smaller, more specific array of means which should provide minimal choice in order to continue successfully pursuing their goal. We investigated this hypothesis across 3 studies. Study 1 demonstrated that when in a goal progress mindset, participants indicated intention to pursue a goal when they had a larger means set available than a smaller means set. In Study 2, we manipulated perceptions of goal progress and found that though there was no difference in intention to pursue a goal with either a small or large means set in a low goal progress mindset, there was a significant difference when participants perceived significant progress. Perceptions of significant goal progress led to a preference for the smaller means set over the larger one. Study 3 replicated these findings on multiple dimensions of means variability (size and composition). Implications for self-regulation are discussed.
Advisor: Donald Lysle (Psychology and Neuroscience)
Undergraduate Co-Authors: n/a
Graduate Student Contributors: Meghan Jones
Faculty/Postdoc Contributors: Donald Lysle
Abstract: Post-Traumatic Stress Disorder (PTSD) is a debilitating mental disorder imposing severe fiscal and emotional costs on society. Current treatments for PTSD include cognitive and exposure therapies, and EMDR, but no FDA approved pharmaceutical treatment. One goal of our laboratory is to understand the neurobiological mechanisms driving PTSD to identify potential targets for the development of novel pharmaceutical treatments. To this end, we employ an animal model of PTSD, stress-enhanced fear learning (SEFL). SEFL is based on foot shock fear conditioning, but is a maladaptive form of hyperractive fear. In the model, a severe stressor changes how a future mild stressor is processed and induces generalized anxiety-like behavior. We have reliably established this model in our laboratory but, traditionally, have relied exclusively on male subjects, and post-stress behavioral patterns differ between male and female rats. The study's aim was to optimize the SEFL model for female subjects. Interestingly, in Experiment 1, female subjects did not exhibit enhanced fear learning to the mild stressor with the same stress parameters as male subjects. However, in Experiment 2, we showed that with an increase in the severity of the milk stressor, female subjects exhibited significant SEFL, comparable to male subjects. Using this model, we can study the neurobiological mechanisms driving PTSD in female and male subjects, and can explore potential sex differences in the neurobiology of PTSD.
Advisor: C. Ryan Miller (Pathology)
Graduate Student Contributors: Robert McNeill, Juanita Limas
Abstract: Glioblastoma (GBM), a grade IV astrocytoma, is the most common malignant primary brain tumor. The receptor tyrosine kinase (RTK) pathway, including its mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3K) effector arms, is frequently mutated in GBM. Moreover, mutational activation of PI3K and MAPK signaling via Pten/PIK3R1 mutations and constitutively active mutant RAS cooperate to promote gliomagenesis. Mutations in the catalytic subunit of PI3K, PIK3CA, occur across multiple domains in GBM. We previously utilized immortalized normal human astrocytes (NHA) with and without expression of oncogenic RAS to determine that helical and kinase, but not adaptor-binding (ABD), domains of PIK3CA mutations increased PI3K signaling and potentiated gliomagenesis in vitro and in vivo. Because there is extensive cross-talk between PI3K and MAPK pathways, we next tested whether PIK3CA mutations influenced response to PI3K or MEK inhibitors. PI3Ki and MEKi as single agents reduced growth, but activated the alternate pathway. Therefore, we also measured the effects of PI3K and MEK inhibitors in combination. We found that buparlisib and selumetinib were synergistic across all mutations, but most pronounced in cell lines harboring mutations in ABD and helical domains. Therefore, targeted combination therapy in vivo could be effective in treating GBM containing ABD or helical domain PIK3CA mutations.
Advisor: Mark Hollins (Psychology and Neuroscience)
Abstract: This research study explores the effects of a history of chronic pain on current pain perception and executive function. We asked subjects to report any chronic pain earlier in life and to indicate the ages at which it occurred. Two measures of executive function were used. The Operation Span (OSPAN) test measured the ability to move numerical and verbal information in and out of working memory, while the Stroop task tested the ability to suppress salient but irrelevant information in the form of color names. We also studied the ability of one pain to modulate another (conditioned pain modulation, CPM), a perceptual analogue of executive function (Yarnitsky, 2015). To measure CPM, we asked subjects to rate pressure stimuli on one arm while the opposite hand was placed either in painfully cold or thermally neutral water, and compared the two sets of ratings. Catastrophizing and hypervigilance were also measured, because these perceptual/cognitive habits can sometimes influence pain. Analyses will statistically compare these five measures of central processing in individuals with and without a history of chronic pain. This research will help to answer the question of whether chronic pain during childhood and/or adolescence has long-term effects on perception and cognition in young adults.
Advisor: Brian Pietrosimone (Exercise and Sports Science)
Abstract: The objective of this research is to determine the association between walking biomechanics and compartmental femoral cartilage area deformation using ultrasonography. Thirty-eight healthy participants with no history of lower-extremity injury volunteered for this study. Medial and Lateral femoral cartilage area was assessed with ultrasound before and after a treadmill protocol (i.e. approximately 5,000 steps). Cartilage deformation was calculated as a percent change from before to the walking protocol for both femoral compartments. Peak vertical ground reaction force magnitude (vGRF) and loading rate (vGRF-LR) were determined in our motion capture laboratory. Pearson product moment correlations were used to determine the association between femoral cartilage deformation (i.e. medial and lateral) and walking biomechanics (i.e vGRF and vGRF-LR). Greater medial femoral cartilage deformation was significantly associated with lesser vGRF-LR (r=0.404, p=0.012), but not with peak vGRF. Lateral femoral cartilage deformation was not significantly associated with peak vGRF or VGRF-LR. These findings indicate that rate of loading, rather than overall magnitude of load, is related to medial femoral cartilage deformation. More research is needed to determine if the cartilage in individuals following acute knee injuries responds differently than the cartilage of healthy individuals.
Advisor: Gary Glish (Chemistry)
Graduate Student Contributors: James Keating
Abstract: E-cigarettes are an emerging tobacco product that is rapidly gaining popularity, but little is known about the formulation of the e-liquids. Currently, manufacturers are not required to disclose product formulations, which makes it difficult to understand the public health impact of the emerging product. Mass spectrometry provides a highly sensitive and selective means of identifying compounds that are being included in these e-cigarette and e-liquid products. Artificial sweeteners and sugars have both been detected in flavored e-liquids, adding to our understanding of product formulations. Sucralose was readily identified based on the isotope ratio inherent to compounds containing three chlorines, and confirmed with MS/MS and a sucralose standard, using both positive and negative ion mode. The direct infusion ESI MS approach was used to screen a large number of e-liquids to gain an understanding of the frequency with which these sweeteners are being included in the products.
Advisor: Todd Thiele (Psychology & Neuroscience )
Abstract: The role of the lateral hypothalamus (LH) in reward and feeding behavior has been extensively examined in relation to its role in binge-like ethanol consumption. Studies suggest a linkage between norepinephrine and binge drinking behavior originating from the locus coeruleus (LC) and A2 region of the nucleus tractus solitaries (NTS). These two areas are known to play a role in both reward-seeking and consummatory behavior. Recent (unpublished) data shows a projection from these regions to the LH, suggesting that noradrenergic innervation of the LH may influence consummatory behavior including ethanol consumption. To assess this possibility, we chose to pharmacologically activate alpha-1 adrenergic receptors in the LH. Male and female C57BL/6J mice were stereotaxically implanted with LH-targeted cannulae. Mice were then run in consecutive 4-day "Drinking-in-the-Dark" (DID) cycles in Latin square fashion. Our manipulation revealed that alpha-1 agonism in the LH dose-and time-dependently reduces ethanol consumption but had no effect on sucrose consumption. The highest dose tested failed to alter locomotor activity in an open field test, but appears to be anxiogenic as measured by time spent in the center portion of the chamber. These findings suggest that alpha-1 adrenergic receptor activity may modulate binge-like ethanol consumption uniquely. Ongoing studies seek to elucidate the relative influence of A2→LH and LC→LH pathways in modulation of this effect via DREADD technology.
Advisor: Dr. Tamera Coyne-Beasley (UNC General Pediatrics and Adolescent Medicine)
Undergraduate Co-Authors: Marni Krehnbrink, Beatriz Vega, Emilie Kahdem
Abstract: Background: In 2015, 13% of U.S. teens aged 12-17 had at least one depressive episode. Low social support can be associated with depression. Objective: To determine if social support is associated with adolescent depression. Design/Methods: Data were from patients, ages 11-21 at a clinic from 2012-2016. Demographics were abstracted through electronic medical records; a GAPS survey was used to collect data on risky behaviors. PHQ9 was used to screen for depression; a score of ???11 indicated a positive screen. Chi-square analyses assessed associations of depression, demographics and social support. Results:839 males(48.8%) and females(51.2%) participated. Participants were diverse(18.4% white; 42.0% black; 31.0% Hispanic, 8.34% other); the mean age was 14 years. 11% screened positive for depression. Those with a positive depression screen were more likely to report not having someone to talk to about their problems(p<0.001) and were more likely to report problems at home (p<0.001). Depression was significantly associated with being female(p<0.041) and Hispanic(p<0.045). Hispanics were also less likely to have someone to talk about their problems(p<0.001) and more worried about problems at home(p<0.001). Conclusions: Some demographics and levels of social support may have associations with depression. Females and Hispanics had greater associations with depression when compared to their counterparts. Asking about adolescents' social support may be useful to assess depression risk.
Advisor: Adam Zanation and Corey Johnson ()
Abstract: The common carotid artery serves a major role in delivering oxygenated blood to the body's head and neck. It splits into two branches: internal and external, upon bifurcation at the superior border of the thyroid cartilage. The internal carotid artery (ICA) courses up to supply oxygen to the brain, while the external carotid artery (ECA) supplies blood to the external structures of the skull, such as the face. Restricting blood flow to either of these arteries can heave deadly affects and can potentially lead to a stroke and need for a carotid bypass surgery. The purpose of this study was to determine the surgical exposure of the ECA for potential bypass with progressive exposures as the primary outcome and to determine the number of identifiable ECA branches each dissection produces as the secondary outcome. Four male latex-injected cadaver heads and a total of eight consecutive dissections were used in this anatomical study using three progressive approaches: transcervical, with addition of submandibular gland removal, and with parotidectomy. There was a statistically significant difference when comparing the ECA exposure between the transcervical and submandibular dissection approaches, but not between the submandibular and parotid gland removals. Additionally, the submandibular gland removal provided the most significant increase in exposure of the ECA during progressive dissections.
Advisor: Brian Button (Marisco Lung Institute )
Abstract: Cough clearance is widely known for its significance in diagnosing breathing ailments, in helping to clear blocked airways and in maintaining health. In patients with Cystic Fibrosis, the high velocity and shear forces associated with cough may help to break away mucus from the lumen, and clear pathologic, concentrated and highly viscoelastic mucus. To better understand why cough-clearance fails in CF, we developed an in vitro "cough machine" which incorporates human bronchial epithelial cell cultures with endogenous mucus over a range of mucus concentrations to study effects of air flow rates in the cough regime. In this study, we investigated mucus clearance rates by airflow that simulated cough. The cough clearance of mucus was captured by observing particles that were stuck to mucus and by using a hi-speed camera during airflow pulses that lasted for a fraction of a second, which emulates a cough event. The results helped correlate complex relationships between various mucus properties such as mucus concentration, oncotic pressure, and rheological properties. Overall, we found that this in vitro cough clearance model elucidated cough clearance as a relationship with mucus solids concentration, which in turn predicted mucus oncotic pressure and rheological properties. We anticipate that drug therapeutics that modify viscoelastic properties may improve cough clearance rates for both mild and severe CF-like mucus concentrations.
Advisor: Ron Alterovitz (Computer Science)
Abstract: Previously, Jeffrey Ichnowski proposed a method for splitting the computation of a robot's motion-plan between the robot???s low-powered processor and a cloud-based high-powered compute-optimized server. We evaluate the experimental performance of this method with the compute service offered by Amazon across different robot-server scenarios to meet the dynamic requirements common in the environment of a home-assistance robot. Comparing across different data centers around the world, we investigate the network time elapsed during the plan-transmission process, the total time taken to complete a robot-scenario task, and the number of vertices and edges generated for each roadmap during the planning process. We use these results to estimate the cost of such pay-per-use cloud service in this new planning method to evaluate its economic desirability against a traditional capital-expense model. As we predicted, with one exception, network time and total solve-time increase with the geographical distance from the data center, whereas graph size decreases. We find that, ignoring upgrades in technology and expected performance-depreciations, using commercial cloud services becomes costlier once we cross a certain time-threshold. Furthermore, higher compute-power may not be most preferable when operating costs are considered. Finally, the exceptions indicate that better comparisons and benchmarks can be evaluated if they are controlled for more variables.
Advisor: Diane Pozefsky (Computer Science)
Abstract: This thesis details a novel approach to the rendering of a real-time 360-degree in-browser environment from a set of disjoint live camera feed. Developed to give police officers better visibility and reporting in the field, this study and the lessons learned during implementation demonstrate progress toward solving a high-stakes limited resolution and affordability problem that occurs when rendering panoramas from today's off-the-shelf 360-degree camera technologies.
Advisor: Prasun Dewan (Computer Science)
Abstract: This paper is concerned with implementing a tool for supporting collaboration between students and instructors in computer programming courses. I begin by abstracting this work flow to encompass other collaboration scenarios, then proceed to describe an architecture to support it which demonstrates proportional reuse; i.e. the architecture is reusable in different scenarios to the extent that they are similar to the driving problem. Next I give a detailed implementation of this architecture in the popular IDE Eclipse and evaluate how well it meets the design goals of being scalable and interoperating with existing technologies, both of which it satisfies. I also provide an implementation of the architecture for microcontrollers and online programming environments to evaluate if the architecture satisfies the proportional reuse requirement, which it does. I conclude with some remarks about the wide applicability of this architecture and ways in which its implementations can be extended.
Advisor: Blaire Steinwand (Biology)
Undergraduate Co-Authors: Rachel Peterson, Meredith McNairy
Abstract: The purpose of this research is to quantify mislabeling of shrimp sold on the North Carolina coast labeled as local shrimp. Seafood mislabeling is when one species of fish is sold as another type of fish, or when a species is stated as being from a place other than where it was actually caught. Consumers pay a higher price when they believe they are buying local shrimp, when in reality, it could be sourced from anywhere in the world, including areas where social justice issues, such as slave labor, indirectly contribute to shrimp farming, in addition to shrimp that could be collected through unsustainable means of fishing. In this study, we identified mislabeled shrimp by using DNA barcoding technology on 24 samples purchased during the summer of 2016 from fish markets, grocery stores, and restaurants. After comparing each sample???s DNA sequence to known species??? sequences, we found 67% of samples to be mislabeled. The lack of transparency in the shrimping industry implied by these results, in addition to unnecessarily high prices for consumers, may include contribution to human trafficking and continued unsustainable shrimping practices that thwart conservation efforts.
Advisor: Nicholas Law (Physics and Astronomy)
Abstract: We present a survey of approximately 50000 G-type stars in the southern hemisphere using the Evryscope (http://evryscope.astro.unc.edu), an array of telescopes located at the CTIO Observatory in Chile, capable of continuously imaging the entire accessible sky simultaneously. With the aim of identifying transiting exoplanets, we performed a box-least-squares (BLS) analysis on the light curves recorded for these stars. While the primary goal of this research is locating exoplanets, we also observe and catalogue types and abundance of variability in G stars, as well as transiting binary stars.
Advisor: John Bruno (Biology)
Undergraduate Co-Authors: Olivia Gorman, Allie Vansant
Abstract: Past seafood mislabeling studies have revealed significant inconsistencies in labeling practices. Such prevalent mislabeling raises public health, ecological, and conservation concerns. The purpose of our study was to measure seafood mislabeling in the Chapel Hill-Carrboro area. Samples of Red Snapper, Yellowtail, Yellowfin Tuna, Bluefin Tuna, and ???Whitefish??? were obtained from seven sushi restaurants and three different grocery stores. We used DNA barcoding to determine the genetic identity of 27 samples. Our results revealed two types of mislabeling, explicit mislabeling by species substitution, and ???soft??? mislabeling, in which the commercial label uses a generic name that does not identify one single species, e.g., ???snapper???. Of the samples identified, 56% were mislabeled, with seven explicitly mislabeled and eight falling under our definition of soft mislabeling. Our results were consistent with previous studies in that higher market value fish, like Red Snapper and Bluefin Tuna are often replaced by lower market value fish, such as Crimson Snapper and Yellowfin Tuna. Soft mislabeling reveals a similar trend, in which generic labels conceal the identity of lower market value fish. Overall, this research shows that both explicit and soft mislabeling are shockingly common occurrences, with many negative consequences in the area of public health, like concerns over allergens and mercury levels, and in the field of marine conservation.
Advisor: Nick Law (Physics/Astronomy)
Abstract: A recent data survey of 3313 Kepler planetary hosts from the Robo-Adaptive Optics team has provided potential insight into the effects of stellar multiplicity on exoplanet transit signals. Using two different methods we search for stellar companions to the observed target stars. Initially, team members scan each 8???x8??? frame for a visible companion within 4??? of the primary star. This ???by-eye??? method is followed by an automated photometry program which detects stellar companions. For the nearby (25 parsec) stars the overall probability rate for multiplicity is 14.5 +/- 0.8 %. For bright targets with magnitude 6 and below another ???by-eye??? search was performed to probe the likelihood that non-companion related signals such as cosmic rays, aperture effects, and large point spread functions will provide a false positive for a stellar companion. From the visual search these false-positives seem unlikely, however, further photometry is performed on the bright targets to compare their multiplicity rate (approx. 8.1 +/- 0.8 %) to the average. Finally, further data will need to be collected for the primary targets so that stronger correlations may be made between the multiplicity of a system and the evolution of its planets if it has any.
Advisor: Blaire Steinwand (biology)
Undergraduate Co-Authors: Nick Badhwa
Abstract: Seafood mislabeling is becoming an increasingly common problem worldwide. Beyond the ethical and economic concerns of seafood fraud, mislabeling also has far reaching health and environmental effects. Consumers with dietary allergies or restrictions can be negatively affected by eating the wrong species. This may be harmful because concentrations of mercury and other toxins in some fish may be higher than in other species. Furthermore, mislabeling can undermine programs protecting endangered species because it can increase fishing by creating the illusion of abundance. We used DNA barcoding to quantify mislabeling of seafood sold at grocery stores and restaurants in the Chapel Hill-Carrboro area over a four-month period. Our preliminary results have indicated 15 unique cases of mislabeling out of 27 collected samples. Of the 15 mislabeled samples, 7 were found to be of a completely different species while the other 8 were generically or vaguely labeled. Our results indicate that species like yellowfin tuna and yellowtail snapper are often correctly labeled, while Nile tilapia is often substituted for red snapper. The extent of mislabeling suggests that action needs be taken and policies must be developed to promote more sustainable and informed seafood consumption and curb the rise of seafood mislabeling.
Advisor: Nita Eskew (Chemistry)
Undergraduate Co-Authors: Paige Trexler, Madeline White, Jacob Stocks, Makala Moyer
Abstract: Portulaca olercera is a warm-climate plant grown in tropical and subtropical areas of the world. It is know as purslane in the United States and has developed into both a medicinal plant and a product in foods. Purslane has been identified as having antioxidant properties which remove reactive oxygen species during metabolic reactions. This study was conducted to determine if the concentrations of antioxidants in purslane will vary based on their growth environment. The antioxidant concentration of extracts of 2 homogenous mixtures of red purslane grown in Chapel Hill, North Carolina at two different locations were analyzed using a DPPH assay and UV/Vis Spectroscopy.
Advisor: Joyce Besheer, Ph.D. (Psychiatry)
Abstract: Alcohol use disorders (AUDs) are a major public health issue. As such, understanding the underlying causes of these disorders is an area of particular interest. Stress has long been associated with increases in alcohol drinking. During the body???s stress response, glucocorticoids (cortisol in humans and corticosterone (CORT) in rats) are released. Previous work has modeled the effects of prolonged exposure to CORT and examined its effect on alcohol self-administration in male rats. However, the role of sex in the effects of chronic CORT exposure on alcohol self-administration has not been studied. In the present study, adult male and female rats were trained to self-administer alcohol. After initial training, rats were given a week of either CORT or water exposure in the home cage. Rats were then tested to assess relapse-like responding to examine whether there were sex-related effects of CORT exposure on alcohol seeking and self-administration. A later reinstatement test was also given following protracted abstinence (41 days). Animals then self-administered alcohol normally in the weeks following the second test. While no significant differences were found during the first reinstatement test, differences emerged following the long abstinence period in both relapse-like behavior and subsequent self-administration, with CORT males significantly different than water males (females showed no differences). This data suggests differing long-term responses to stress between sexes.
Advisor: Leslie Hicks (Chemistry)
Abstract: While historical screening efforts on drug discovery have largely focused on small molecule constituents of natural products, the antimicrobial drugs made from these small molecules have cultivated resistance in many microorganisms. Recent studies have shown that ribosomally-synthesized, post-translationally-modified peptide natural products (RiPPs) have the potential to address this urgent need for new therapeutic compounds due to their target specificity, high potency and metabolic stability. While these bioactive RiPPs are ubiquitously expressed in nature, plants are a promising and largely unexplored source for these peptides. To expedite the search for novel bioactive peptides, the PepSAVI-MS (Statistically guided bioactive peptides prioritized via mass spectrometry) pipeline was developed in the Hicks Lab. This pipeline begins with zero knowledge about the peptide profile of the species, but quickly determines the most-likely bioactive peptide targets. In this project, plant species H. cordata and L. japonica were subjected to PepSAVI-MS. Our data showed that fractions of their peptide libraries exhibit strong bioactivity against E. coli, as well as the multi-drug resistant pathogens A. baumannii, K. pneumoniae, and S. aureus. The putative antimicrobial peptide candidates were identified using a hybrid LC-MS/MS and statistical analysis-based approach. Purification and structural characterization of promising targets will be carried out in the future.
Advisor: Nita Eskew (Chemistry)
Undergraduate Co-Authors: Annabel Chung, Haley Leazer, Mariah Moyer, and Jamie Rose
Abstract: Purslane (Portulaca oleracea) is known to be rich in antioxidants, vitamins, and fatty acids. To find out where the plant has the highest concentration of antioxidants, each individual part (leaves, stems, and roots) was examined. Each part was subject to extraction via reflux in ethanol and diluted. A DPPH assay was run to determine antioxidant activity, and each plant parts absorbance was recorded at 517 nm. The results show the highest amount of antioxidant activity in the roots of the plant, followed by the stems and leaves. Future research is needed to determine which antioxidants are present and the exact concentration.
Advisor: Joyce Besheer (UNC School of Medicine)
Abstract: The well-established sucrose-fading protocol is often used to establish operant alcohol self-administration in rodents. The standard sucrose-fading method requires water restriction and/or extended training to initiate lever responding in rats. The purpose of this experiment was to test whether food restriction during the sucrose-fading process would successfully increase alcohol self-administration and decrease variability in acquisition. Food restriction eliminates the need for water restriction, and motivates the rats to self-administer alcohol therefore reducing the length of training. Male (N=6) and female (N=5) Long-Evans rats were kept at 90% of their original body weight throughout food restriction. After successful completion of an overnight session, the rats began sucrose-fading. The final solution the rats received was 2 percent sucrose and 15 percent ethanol by volume. After three weeks, food restriction was gradually eliminated and and rats had unlimited food access. Ending the food restriction caused a significant decrease in responses, alcohol intake, and locomotor rate for both male and female rats. Therefore, while food restriction produces higher and more consistent alcohol intake, this level of alcohol intake does not persist once unlimited food access is introduced.
Advisor: Nita Eskew (Chemistry)
Undergraduate Co-Authors: Madeline Cooke, Hannah Richey, Grant Pieples, Julia Shen
Graduate Student Contributors: Megan Ford, Koty Swanson
Abstract: Portulaca oleracea, commonly known as purslane, is a herbaceous succulent plant with a diverse array of compounds that exhibit nutritional and medicinal properties. In particular, this plant is a rich source of antioxidants including vitamin A, omega-3 fatty acids, and α-tocopherols. We developed a procedure using ultrasonication to optimize the extraction of antioxidant compounds from red purslane leaf tissue. In particular we focused on the efficiency of different extraction solvents: water, ethanol, and acetonitrile. We employed the 2,2-diphenyl-1-picryhydrazyl (DPPH) radical scavenging assay to evaluate the relative concentration of antioxidants in our extract solutions. We concluded that the maximal extraction of antioxidants was produced via a water solvent. By optimizing an antioxidant extraction procedure for Portulaca oleracea, we hope to promote future research in the medicinal properties of this plant.
Advisor: Joyce Besheer (Psychology)
Abstract: Alcoholism is a substance abuse disorder that millions of Americans receive treatment for every year. Understanding the neural circuitry involved in the role of internal cues on modulating alcohol self-administration will provide important information about the neural mechanisms of alcohol seeking. The goal of this study was to investigate the functional role of the insular cortex (IC) and the insular cortex -> nucleus accumbens core (AcbC) projection in modulating alcohol self-administration. Previous studies have implicated the connection between IC and AcbC is important in deciding when the value in the incentive of drinking is high or not high enough to perform the behavior necessary to obtain the alcohol.If the incentive is high enough, the IC sends a signal to the AcbC, a contributor of dopamine production, increasing alcohol self-administration. Male Long-Evans rats were trained to self-administer alcohol and a chemogenetic strategy was used to silence the IC or IC->AcbC projections (hM4Di DREADDs).The incentive value of alcohol self-administration was increased using a low concentration alcohol loading dose prior to the self-administration session. We hypothesized that the rats with silenced IC or IC->AcbC projections would have a decreased response during alcohol self-administration after a preload dose is given, because the IC, which usually excites the AcbC more due to the higher incentive value of alcohol, would no longer be as active due to chemogenetic silencing
Advisor: Nita Eskew (Chemistry)
Undergraduate Co-Authors: Andrea Anuel, Andrew Cesmat, Sarah Chyriwski, Nancy Diaderas
Abstract: Purslane (Portulaca oleracea L.) has been reported to possess potent pharmacological activities due to its antioxidant properties and nutritional value. The main objective of this research was to appraise antioxidant attributes of two varieties of purslane, red and golden. The antioxidant activity was measured using 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. Activity was portrayed in measurement of absorbance values of DPPH and plants extracts. Golden purslane leaves show a third of the abosrbance value red purslane leaves exhibited. Overall this concludes that golden purslane leaves have higher levels of antioxidants.
Advisor: Sarah Linnstaedt (Anesthesiology)
Faculty/Postdoc Contributors: King T, Liberzon I, Lewandowski C, Hendry PL, Pearson C, Wang HE, Damiron K, Velilla MA, Domeier R, McLean SA
Abstract: PTSD and chronic widespread pain (CWP) are frequent co-morbid sequelae of trauma that occur at different rates in women and men. We sought to identify microRNA that may contribute to sex-dependent differences in vulnerability to these outcomes using in silico, human, molecular, and animal data. Monte Carlo simulations identified miRNA in which predicted targeting of PTSD or CWP genes was most enriched (p<0.05). Expression of the miRNA most strongly predicted to target PTSD and CWP genes in these simulations, miR-19b, has been shown to be influenced by estrogen and stress exposure. We evaluated whether peritraumatic miR-19b blood expression predicted PTSD and CWP development in a cohort of individuals experiencing motor vehicle collision (MVC) (n=178), and whether miR-19b was sex-dependent in an animal models of stress exposure. A sex-dependent relationship was observed between initial miR-19b levels and both PTSD development (miR-19b*sex interaction OR=1.41, p=0.039) and CWP development (miR-19b*sex interaction OR=1.46, p=0.031) 6 months following MVC. Sex-dependent expression of miR-19b was also observed in two animal models. The potential importance of miR-19b to PTSD/CWP pathogenesis is supported by further analyses indicating that: miR-19b targets are enriched in the circadian rhythm (CR) pathway, miR-19b expression is negatively correlated with key CR transcripts following MVC, such as CLOCK and RORA, and miR-19b directly binds targets in in vitro binding studies.
Advisor: Christian Iliadis (Department of Physics & Astronomy)
Faculty/Postdoc Contributors: Dr. Larry K. Benninger
Abstract: During the decay of radioisotopes, an unstable atom will release energy in an attempt to gain stability. This energy is often released in the form of ??-rays, which correspond to discrete changes in the energy level of the atom. For some radioisotopes, ??-rays can be measured in coincidence with each other, as the nucleus transitions through several energy states simultaneously. By using two NaI(Tl) detectors, a spectrometer can be built such that it only takes measurements when both detectors register a ??-ray simultaneously. By utilizing this criteria, a significant amount of background radiation can be reduced, as it will not act in coincidence with both detectors. Using the newly built ?? ?? coincidence spectrometer at the University of North Carolina Chapel Hill, radioactivity can be determined in samples of soil and food. Radiation caused by natural sources, such as uranium-238 and thorium-232, as well as their daughter isotopes, was investigated in samples of Brazil nuts, soil, and glossy paper.