The poster session for the fifteenth 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 (1:00-2:00); even-numbered posters will be in poster session 2 (2:15-3:15). Students are generally grouped by major.
Click on the title of the student's poster to read the abstract and see any other research contributors.
Disciplines are noted to the side of each presenter: Arts and Humanities (AH), Social Sciences (SS), and Natural Sciences (NS).
Abstract: In brief, my research entitled "Machismo and Mama T'allas: Intersections of Policies and Personal Experience for Women in the Bolivian Andes" presents an exploratory look into the personal and political lives of women living in rural agricultural communities in the municipality of Pocoata in the department of Norte de Potosí, Bolivia. My ethnographic style interviews center around the life histories of the women and their understanding of the current politics of the Evo Morales' administration and the perceived effects of seemingly more progressive policies related to education, female leadership, land rights, maternal/child health, and interpersonal violence prevention in their lives. My interviews include a sampling from female leaders and government workers in Pocoata who elaborated on both the progress and constraints facing women in the current political, economic, and social context. Through a diverse range of interviews, I piece together a collective story arc of the contradictions between the limitations and agency women experience in political representation, voice, and legitimate policy implementation. My research ends in a series of questions that could be probed further to explore ways that more meaningful bridges could be built between macro-level policies and the personal lives of women in this specific local of the Bolivian Andes.
Abstract: This experiment compared the pharmacokinetics of PRINT ® nanoparticle-bound cisplatin (Print-platin ®) to that of free cisplatin (a common chemotherapeutic drug) in mice with the LKB498 lung cancer strain. PRINT ® is a nanoparticle formulation tool invented by Dr. Joseph DeSimone. The objective of incorporating a chemotherapy drug into a nanoparticle is to target the drug more directly towards the tumor, thus increasing the effectiveness of the treatment and reducing systemic toxicity. Mice infected with the LKB498 cancer strain were used to investigate this effect in this experiment. Half of the mice were injected with PRINT-platin ® and half were injected with free cisplatin at the same dosage. At 5 time points after injection (5 min, 30 min, 1 hour, 6 hours, and 24 hours), 3 mice treated with PRINT-platin ® and 3 mice treated with free cisplatin were euthanized for organ harvesting. Organ samples were then analyzed for platinum concentration using an inductively coupled plasma-mass spectrometry apparatus. Changes in platinum concentration were representative of changes in cisplatin concentration over time after injection. Experimental data showed that, compared to free cisplatin, PRINT-platin ® circulated in the bloodstream for longer and accumulated in the tumor more effectively. It also showed that PRINT-platin ® accumulated in the kidney less than free cisplatin, which is important because cisplatin has significant renal toxicity.
Abstract: Isolating desired cell lines from a sample is a critical step in a lot of biomedical research. There are multiple to isolate and sort cells, such as fluorescence-activated cell sorting and microarrays containing releasable, magnetic plastic rafts. The latter technology was studied to optimize the thickness of the arrays to maximize imaging quality while also maintaining the efficiency and reliability of isolating a desired cell line. This was done by varying the thickness of the microwell arrays and quantifying the number of attempts to release a raft as well as the number of additional, undesired rafts were released. It was found that thicker arrays improved imaging quality by reducing sag of the arrays and also retained the reliability of the raft release.
Abstract: Triple Negative Breast Cancer are invasive, metastatic tumors that lack the three cellular receptors that are most commonly targeted by current chemotherapies: Estrogen Receptor (ER), Progesterone Receptor (PR), and Human Epidermal Growth Factor Receptor- 2 (Her2). With limited treatment options, this diagnosis typically carries poor prognosis. The CXCL12/CXCR4 signaling pathway is known to play a role in breast cancer metastasis. G protein coupled receptor kinase 3 (GRK3) is a negative regulator of CXCR4 activity. We show that GRK3 knockdown breast cancer cells exhibit a more metastatic phenotype in vivo than wild type cell lines. Additionally, we have found cells that expressed lower levels of GRK3 may express higher transcript levels of matrix metallopeptidase-9 (MMP9) or Vascular endothelial growth factor (VEGF), two genes known to be associated with metastasis. AMD3100, a current chemotherapy drug in the clinical trial stages, is a CXCR4 antagonist. We have tested the effect of this drug on both in vitro gene transcription and in vivo metastatic potential. The metastatic potential of GRK3 knockdown breast cancer cells was evaluated using the non-invasive method of bioluminescent imaging. In vivo data suggests that AMD3100 treatment has no effect on metastatic potential in our mouse model and may, in fact, exacerbate tumor growth and metastasis. Our results show a role for GRK3 in the regulation of CXCR4 signals that relate to breast cancer metastasis.
Abstract: Autophagy is a survival mechanism utilized by all eukaryotic cells during nutrient starvation in which the cell recycles cytoplasmic components to the vacuole to degrade and release. Understanding this mechanism can potentially improve cell survival after stroke and heart attack, thus minimizing tissue damage. Macroautophagy,the better known pathway,involves recycling cellular components via a double-membrane bound vesicle, whereas microautophagy is poorly understood and involves the vacuole directly engulfing the cytoplasmic components. Previous internal studies showed glucose starvation inhibited macroautophagy in S. cerevisiae cells; yet, some autophagic activity was detected by an enzymatic assay. To determine whether this activity was due to microautophagy, we deleted a critical gene for macroautophagy, Atg5, and genes that potentially influence microautophagy, Vtc1 and Vtc2, in a Pho8Δ60 strain, allowing us to measure autophagy quantitatively through the Pho8Δ60 enzymatic assay. We starved these strains for nitrogen, glucose, or both nitrogen and glucose for 30 hours and found that Vtc2, not Vtc1 or Atg5, was required for autophagic activity in glucose-starved cells. We concluded that microautophagy occurs in glucose-starved cells, and some of the genes in the vacuolar transporter chaperone (VTC) complex are more important in glucose-starved cells than others. Currently, we are testing selective microautophagy of organelles during glucose starvation.
Abstract: Chronic pain disorders affect over half of the American population and costs the economy billions of dollars in lost productivity. Current research establishes a possible relationship between orofacial pain, chronic headaches, and other chronic pain disorders within a female population. The aim of this study was to further investigate any possible comorbidity between these pain conditions through the use of survey data from a registry of chronic pain patients. The data was comprised of 1473 survey responses that were administered from 2007 to 2013 at UNC Hospitals. The survey established whether or not the respondent was formally diagnosed with a pain condition such as Episodic Migraines, Tempromandibular Joint Disorders, Vulvar Vestibulitis, or Fibromyalgia; and if the respondent was diagnosed or self-reported a variety of urogenital, gastrointestinal, musculoskeletal, sleep-related, or psychiatric disorders. Of the 1204 female registrants, consenting to study participation, 983 (82%) had some form of a pain condition. The average respondent had 2 conditions across the 5 categories, indicating a general comorbidity amongst the chronic pain conditions. The findings of this study show that most patients experiencing some form of chronic pain in one area of the body will also experience pain localized to another area. Therefore, it is important for health care providers to take a holistic approach to chronic pain management versus separate treatment for each condition
Undergraduate Co-Authors: Rachel Swiver
Abstract: Calcium/calmodium dependent protein kinase II (CaMKII) is a post-synaptic density protein that plays a key role in neural plasticity throughout the brain. A primary goal of our research is to understand neuroadaptations in this molecular signaling protein and its association with chronic voluntary ethanol (EtOH) drinking. Our objectives were (1) to address whether a schedule of voluntary access that promotes high EtOH intake (>20g/kg/day) can elicit anxiety-like behavior during withdrawal; and (2) to elucidate the neuroadaptations in CaMKII activity occurring in reward-related brain regions associated with differing schedules of EtOH drinking. Subjects were male C57BL/6J mice, separated into three cohorts; water, continuous and intermittent EtOH groups. A voluntary 2-bottle choice paradigm was used, with water and a second bottle containing either water or EtOH was available, depending on treatment condition. After 26 days, mice in Exp. 1 were tested 8 hours into withdrawal using two behavioral measures of anxiety-like behavior. Parallel mice in Exp. 2 were rapidly decapitated 8 hours into withdrawal. Their brains were harvested and tissue from the prefrontal cortex (PFC) and amygdala (AMY) was homogenized and used for Western Blotting for tCaMKII and pCAMKII protein. Intermittent access to EtOH showed higher EtOH preference and dose consumed/day than mice with continuous access. Activity in the open field did not differ, but the mice in the continuous group had significantly more anxiety-like behavior than water drinkers in the EPM. Both schedules of EtOH intake increased phosphorylation of CaMKII alpha and beta isoforms in the PFC, and a reduction in function of tCaMKIIalpha in the AMY of intermittent drinkers only.
Abstract: We are currently working on a new method that use the affinity of biotin/streptavidin in order to more effectively understand and study the microorganisms that reside in marine sediments. This method could be used to identify genes expressed in response to particular conditions, or ? in low-energy environments such as the deep subsurface ? to investigate whether RNA is turned over at all. This method uses the ?click? chemistry reaction in order to identify the RNA transcripts being produced at a particular time in marine sediments. This process involves the uptake of the RNA analog 5-ethynyl uridine (EU) into incubated cells. After incubation of samples with EU label, total RNA is isolated, tagged with desthiobiotin-azide, and tagged RNA captured with T1 streptavidin beads for further analysis. Our results have shown that this method has been successful in labeling and capturing RNA in various forms of cultured bacteria including E. Coli and B. Subtilis. While yielded results were not as strong for B. Subtilis, the positive results from E.Coli suggest that this method can indeed be used to label and capture RNA from prokaryotic cells. We are currently applying this method now to real samples to determine the plausibility of it?s use and are currently sequencing captured RNA to more comprehensively determine the effectiveness of this method and the types of RNA being captured.
Abstract: Many variations in phenotype between individuals are the result of single nucleotide polymorphisms(SNPs). If a SNP occurs in a regulatory region, it can lead to changes in gene expression levels. Such SNPs which affect mRNA levels are called expression quantitative trait loci. I sought to find eQTLs whose mechanism of action directly affects RNA, as opposed to pre-transcriptional regulation, specifically by altering the binding of small interfering RNA or RNA-binding proteins. Changes in these processes can be due to RNA conformational change or changes in recognition sites, and are important in finding causes of RNA diseases. I computationally analyzed overlap of eQTLs with regulatory sites using SNP data from HapMap and 1000Genomes, eQTL data from the NIH GTEx Project, and regulatory sites from the ENCODE project and other public databases. My goal is to find eQTLs whose mechanism of action directly affects RNA.
Faculty/Postdoc Contributors: Adam T. Melvin
Abstract: The protein p53 plays a role in cellular functions such as DNA repair, cell cycle modulation, and apoptosis. Mutation or inactivation of p53 is a hallmark in many cancer types, affecting up to 22 million people. About half of these patients exhibit decreased p53 levels due to overexpression of its regulatory enzyme murine double minute 2 (MDM2), which decreases p53 levels by facilitating its proteasomal degradation. Due to vital involvement in cellular function, p53 and MDM2 have become targets for new therapeutic designs. As such, there is a need for reporters on MDM2 activity and p53 control via the ubiquitin proteasome system (UPS). Such reporters require the incorporation of a degradation sequence (degron) of p53, which targets the probe to its functional destination, the UPS. This project used a shotgun approach to create a fragment library of a p53 domain, necessary for MDM2 mediated degradation, to identify this minimal degron. Substrates were synthesized using Solid Phase Peptide Synthesis, purified with High Performance Liquid Chromatography (HPLC), and tested via an in vitro assay for their degree of ubiquitination to identify the smallest functional degron. Gel electrophoresis of assay samples demonstrated two substrates that were strongly ubiquitinated and are hypothesized to contain the smallest functional degron. In order to obtain more quantifiable results about substrate ubiquitination, further work is being done to analyze assay results with analytical HPLC.
Faculty/Postdoc Contributors: Anthony Fulford, Raj S. Kasthuri, Andrew M Prentice, Nancy Fisher, Steve M Taylor, Carla Cerami
Abstract: Iron deficiency and malaria are co-morbidities in significant portions of the developing world. Iron deficiency is easily reversed by oral iron supplementation. WHO guidelines recommend universal iron supplementation. However, epidemiological evidence that iron deficiency is protective against malaria infection and that iron supplementation may increase the risk of malaria calls into question the recommendation. Despite clear evidence that iron deficiency is protective against malaria; the biological principles governing the protection have remained elusive. We hypothesize that the erythrocytic stage of malaria infection, which is responsible for all symptoms of disease, is affected by iron deficiency. To address our hypothesis, we compared the growth of the malaria parasite in RBCs donated by individuals with iron deficiency anemia to growth of the parasite in RBCs donated by iron-replete individuals. We observed that malaria growth was significantly reduced in iron deficient RBCs due to (i) decreased invasion of the malaria parasite into iron deficient RBCs and (ii) reduced production of infectious daughter merozoites by parasites within iron deficient RBCs. We conclude that malaria propagation is attenuated in iron deficient RBCs. This may contribute to protection from malaria associated with iron deficiency anemia.
Faculty/Postdoc Contributors: Sandra O'Buckley, Terrence Wong, Andrea Nackley
Abstract: Constitutive activity of NF-κB-associated IKK enhances inflammatory pain sensitivity Objectives: We sought to understand if enhanced IKK activity increases inflammatory pain induced by complete Freund?s adjuvant (CFA) at acute (1 h ? 1 d), subchronic (3 d - 7 d and chronic (9 d -13 d) post-injection time points. We hypothesized that mice with enhanced IKK activity (and thus, NF-κB signaling) would display heightened pain response to CFA as measured by mechanical and thermal pain sensitivity compared to mice with endogenous IKK activity. Methods: Mice received an intraplantar (i.pl.) injection of either CFA (20 L) or control incomplete Freund?s adjuvant (IFA; 20 L). Following injection, mice were assessed for responses to punctate mechanical and thermal heat stimuli over a 13-day period. Results: IKK neg mice exhibited mechanical allodynia, mechanical hyperalgesia, and thermal hyperalgesia only during the acute phase following CFA injection. In contrast, IKK ca mice exhibited mechanical allodynia, mechanical hyperalgesia, and thermal hyperalgesia throughout the acute, subchronic and chronic phases following CFA injection. Conclusion: Here, we find that sustained elevations in IKK, a positive regulator of NF-κB, increase pain sensitivity in an animal model of inflammation. Future studies will explore the molecules downstream of IKK and NF-κB (e.g., catechol-O-methyltransferase (COMT)) that contribute to inflammatory pain.
Abstract: We and others reported the generation of mouse induced cardiomyocytes (iCMs) from cardiac fibroblasts (CFs) or tail tip fibroblasts (TTFs) using cardiac reprogramming factors Gata4, Mef2c and Tbx5 (GMT), which marked an exciting path to regenerating the damaged heart. However, current reprograming approaches involve the introduction of GMT via retroviral transduction, which delivers the factors by genomic integration. Under this approach, adverse effects such as disruption of biologically important endogenous genes cannot be ruled out. Our study aims to develop an non-viral and integration-free delivery method for iCM generation. We intend to take advantage of episomal oriP/EBNA-1 vectors, which are large plasmids that reside and replicate in the host nuclei extrachromosomally, thus resolving the issue of integration. To this end, we generated episomal vector constructs containing the reprogramming factors Gata4, Mef2c, and Tbx5. Using optimized electroporation conditions for primary mouse fibroblasts, we show that the episomal system is able to confer robust expression in mouse cells. In addition, reprogrammed cells express reporter gene as well as cardiac markers in a manner comparable to iCM generation by retroviral transduction. Taken together, our data suggest that the episomal system can be used as an alternative approach for safer generation of iCMs, taking iCM technology closer to future clinical applications.
Abstract: The main challenge for clinical translation of chemosensitizers is how to deliver them selectively to tumors while sparing normal tissue. While traditional drug delivery approaches is unable to accomplish such goal, nanoparticle (NP) drug delivery vehicles is ideally suited for chemosensitizers. NPs are known to accumulate in tumors while having low distribution in normal tissue. In this project, we utilized an established NP platform to deliver wortmannin, a known chemosensitizer. Performing in vivo and in vitro studies on lung cancer cell lines, we found that nanoparticle wortmannin had a significantly decreased toxicity and increased efficacy when compared to free wortmannin as a chemosensitizer for clinically approved chemotherapeutic drugs.
Abstract: Approximately 6,300 new HIV-1 infections occur daily. HIV-1 entry into host cells depends on the Env protein?s use of both the CD4 receptor and one of two co-receptors, CCR5 or CXCR4, with the majority using CCR5. Maraviroc (MVC) serves as a potent antagonist of the CCR5 co-receptor. Due to evidence that transmitted viruses use CCR5, Dr. Garcia-Lerma?s lab at the CDC used a macaque model to investigate efficacy of MVC as a pre-exposure prophylaxis (PrEP) drug. After receiving oral MVC, macaques were challenged with a SHIV (a combination of Simian Immunodeficiency Virus and HIV-1) infection to evaluate the efficacy of MVC in preventing rectal transmission. The trial failed, with 5/6 test subjects becoming infected along with 3/4 controls. We are evaluating the source of this failure. We received samples from 7 of the trial monkeys and of the infecting SHIV, SHIV162P3. Phylogenic trees and highlighter plots were generated from single genome sequencing to represent genetic diversity, which proved low. The env gene from nineteen amplicons has been cloned as a representative sample. Infectivity of affinofile cells with variable CCR5 expression levels will be evaluated in the presence and absence of MVC to determine if high CCR5 expression levels allowed SHIV infection despite MVC?s presence. Work is ongoing, and results are expected within the month. Conclusions will then be drawn regarding the role of CCR5 expression levels in determining MVC?s efficacy as HIV-1 PrEP drug.
Abstract: The Tat pathway is one of two major protein export pathways found in mycobacteria, and is essential to the growth and viability of M. tuberculosis. By targeting the Tat pathway, a new drug could inhibit the virulence and fitness of M. tuberculosis. Previous work has shown that the Tat pathway is required for M. smegmatis growth, a model organism for M. tuberculosis, when using succinate as a carbon source. In order for the bacteria to use succinate as a carbon source, succinate must first be transported from the extracellular environment into the bacterial cytoplasm. The Dct system of carbon transport has been studied extensively and offers a starting location for targeting succinate transport. We hypothesized that the Dct family of proteins, specifically DctP1 and DctP2, would be responsible for succinate import in M. smegmatis, similar to what is seen in other bacteria. Additionally, we hypothesized that DctP1 and DctP2 would be exported through the Tat system, therefore, in the absence of Tat export M. smegmatis would be unable to import succinate. Through the SURF program I was able to make progress in determining which Tat exported proteins in M. smegmatis are responsible for the import of succinate. Results suggest that DctP1 and DctP2 are both transported through the Tat pathway, but are not responsible for succinate transport. The protein DctA, in the same family of proteins, provides the next best possibility for research into Tat export.
Abstract: MicroRNA-137 (mir-137) is a brain-expressed regulator of gene expression that has been associated with schizophrenia. In order to determine mir137?s role in brain development we characterized a mouse with a targeted disruption of mir137?s host gene. We acquired a commercially available gene-targeted mouse for mir137 and characterized its effects on development, behavior and gene expression. Through a series of breeding experiments, we determined that targeting of this gene results in embryonic lethality in the homozygous state (P < 0.001). Matings from heterozygous x heterozygous mice resulted in a significantly increased number of resorbed embryos at embryonic day 11.5 (P<0.0001). Our attempt to rescue embryonic lethality by conditional knockout was unsuccessful?likely due to the gene construct. The behavioral phenotype revealed no clear differences between wild type and heterozygous animals. Allele-specific gene expression data from heterozygous mice revealed little expression from the targeted allele but expression from the wild type allele. The overall levels of mir-137 micro RNA were not different between heterozygous and wild type animals. In conclusion, mice homozygous for the targeted allele must die after implantation but before embryonic day 11.5. Mice heterozygous for the targeted allele must upregulate expression of the remaining allele as indicated by gene expression and behavioral data. Therefore, the mir-137 host transcript is critical for proper development.
Abstract: Primary failure of eruption (PFE) is characterized by non-syndromic eruption failure of secondary teeth in the absence of mechanical obstruction. Recent studies have supported the association between mutations in the Parathyroid Hormone 1 Receptor (PTH1R) and PFE. Clinical differentiation between PFE and ankylosis presents a challenge in orthodontics, and phenotypic studies have shown a broad spectrum of clinical characteristics. Objective: The objective was to investigate the causal relationship of PTH1R mutations in multi-generational families with PFE. Method: Pedigree analysis by inspection and assessment of clinical records was completed for one multi-generational family (N=10) with 8 affected and 2 unaffected individuals. Genetic samples were obtained for 4 affected individuals; direct sequencing of PCR products to analyze the coding regions and intron-exon boundary of the PTH1R gene was completed for 3 samples. Result: Pedigree analysis revealed a familial segregating autosomal dominant trait. A c.1389 T>C variation was found in the coding region of the PTH1R gene for affected individuals (N=3). This known heterozygous alteration is a putative non-functional alteration. Conclusion: PFE results in the failure of the eruption mechanism and orthodontic response of affected teeth ? which makes appropriate diagnosis and treatment imperative. Identification of the putative PTH1R SNP that segregates with the phenotype warrants further investigation to determine causality.
Abstract: Dating ancient shorelines that coincide with periods of warmth on Earth help in predicting the current changes in sea level. Strontium Isotope Stratigraphy (SIS) is one method used for dating, which uses calcium-carbonate shells from organisms found in ancient shoreline deposits. The ratio of 87Sr/86Sr in a shell is measured by using a mass spectrophotometer, and then is compared to modern Sr-isotope ratios in seawater to determine the age. This method of shoreline dating depends on the shells maintaining their original 87Sr/86Sr ratios. By using entire powdered shell samples for analysis, we are assuming that the shell will be entirely homogenous in its original strontium isotope ratio. We predict that some of these calcium carbonate shells, especially the older ones, could have partly altered strontium isotope ratios due to diagenesis in an environment with different Sr-isotope ratios; this would lead to inaccurate dating when sampling the entire shell in the mass spectrophotometer. We are using a Micromill to drill linear samples of cross-sections of shells of different ages, from the outer to the inner, in order to test for changes in 87Sr/86Sr isotopes. We hypothesize that the outer parts of older shells, due to their prolonged contact with the environment and the seawater, will have different 87Sr/86Sr ratios than the inner, more preserved parts of the shell. If this is the case, sampling these whole shells for SIS will lead to inaccurate dating.
Abstract: Mutations in chromatin remodeling complexes are commonly associated with cancer1. More specifically, defects in the SWI/SNF chromatin remodeling family are commonly associated with Hepatocellular Carcinoma, the third most common cancer leading to death1. The SWI/SNF chromatin remodeler family contains two distinct complexes, BAF and PBAF2. These two complexes are differentiated by the ARID domain containing subunit that is present along with core SWI/SNF subunits2. BAF contains ARID1A and PBAF contains ARID22. We set out to understand what happens when levels of ARID1A and ARID2 are lowered by RNAi in Hepatocellular Carcinoma cell line HepG2. Growth assays determined that loss of ARID2 significantly decreases the rate of growth. Coupled with this finding, we also show that expression of other growth regulators are significantly changed when ARID2 and ARID1A are mutated. Immunofluorescence, western blots, and quantitative PCR were employed to validate data from RNA-seq experiments that analyze changes in RNA expression after treatment with siRNA against either ARID1A and ARID2. References 1. Li M. et al. September 2011. Inactivating Mutations of the Chromatin Remodeling Gene ARID2 in Hepatocellular Carcinoma. Nature Genetics. 43:828-29 2. Clapier C., Cairns B. 2009. The Biology of Chromatin Remodeling Complexes. Annu. Rev. Biochem. 78:273-304
Abstract: The development of biofilms, or microbial communities formed within a self-produced extracellular matrix, is an important function for many microbes. Biofilms not only increase antibiotic resistance, but also the ability of microbes to adhere to both abiotic and biotic surfaces. As a consequence, the biofilms of pathogenic bacteria are able to form in biological hosts and on abiotic surfaces such as IV catheters. Quorum sensing has been recognized as an important aspect of communication between bacteria, with these signals ranging from small molecules to proteins, serving a myriad of functions, such as regulation of gene expression. In a previous study, a variety of Bacillus species were found to induce biofilm formation in Bacillus subtilis via small molecule secretion. Taking a complementary approach, I used a co-culture screen to identify soil microbes that inhibit biofilm formation in B. subtilis. This screen uses a strain of B. subtilis with a fluorescent reporter gene that is expressed when biofilm matrix genes are being inhibited. By growing B. subtilis alongside other bacterial isolates on a medium that induces biofilm formation; biofilm-inhibited colonies are easily identifiable via fluorescence. Using fluorescence and phenotypic evidence, I have identified two soil Pseudomonads that inhibit biofilm formation. Current work is now focused on isolating and characterizing the compound(s) responsible for this biofilm inhibition.
Abstract: Synthesis-dependent strand annealing (SDSA) is a DNA repair process closely associated with the generation of non-crossover outcomes during homologous recombination. Based on previous studies, Blm, the Bloom?s syndrome helicase gene, is thought to be an essential regulator of SDSA. The purpose of my research is to evaluate another candidate regulator called rtel, the Drosophila ortholog of human RTEL-1, which is hypothesized to play a non-essential but significant role in SDSA repair. My study utilizes a novel genetic construct to measure levels of SDSA repair occurring in the brains of Blm and rtel mutant larvae through changes in cellular fluorescence. Successful SDSA repair of double-strand breaks in the construct result in a visible change in cell color from red to green. So far, results support the initial hypothesis and the assay has been found to be a useful in-vivo method of studying SDSA in Drosophila.
Abstract: The transcription factor Sox2 plays a key role in neural development where its expression is necessary in neural stem cells for maintaining pluripotency. Sox2 expression has also been associated with various cancers, including glioblastoma (GBM), the most aggressive and common form of primary brain cancer that remains incurable. The underlying mechanism of GBM origination and proliferation are poorly understood, and the function of Sox2 still remains unknown. The consequences of Sox2 depletion were investigated in glioblastoma stem cell (GSC) lines derived from genetically engineered mice that contain genetic alterations most commonly found in human GBM. Sox2 knockdown was achieved through activation of a shRNA hairpin directed against Sox2 and led to more than 70% depletion of Sox2 protein in all cell lines, although the functional outcome differed. Cells with disrupted control over the G1/S cell cycle checkpoint entered into cell cycle arrest and stopped proliferating. Additional constitutive activation of the Ras-MAPK pathway did not overcome cell growth inhibition. However, the additional deletion of the tumor suppressor PTEN resulted in insensitivity to Sox2 deletion. These results suggest that GSC with the complex genetic lesions, as found in GBM, can evade the downregulation of Sox2 and maintain characteristics of neural stem cells. Future research will determine how these GSC maintain stem cell characteristics in absence of the essential transcription factor Sox2.
Abstract: Centrosomes are highly regulated microtubule-organizing centers which serve as the primary site of microtubule nucleation in the cell. The fundamental ability of centrosomes to nucleate and anchor microtubules has important implications in many cellular processes such as organization of the microtubule cytoskeleton and regulation of cell division. Thus, tight regulation of centrosome composition and number is imperative in maintaining healthy cells. Our lab is interested in determining the structure and biochemical composition of key proteins involved in regulation of the centrosome. My current research focuses on the purification of the scaffolding protein Asterless (Asl) in two analogous systems, Drosophila melanogaster and Homo sapiens. By crystallizing Asl, structural determination through X-ray crystallography can be performed. Biochemical assays will also be conducted to determine the endogenous conformation of Asl. Previously, I have shown a novel localization of the third fragment of Asl to the centrosome. Asl has also been shown to recruit Plk4, the master regulator of centrosome duplication. Therefore, current experiments focus on finding the minimal domain of this third fragment that will localize to the centrosome in order to identify the possible region of interaction between Asl and Plk4. Through structural and biochemical assays of these key proteins, we hope to gain insight into the structural basis and the important regulation mechanisms of the centrosome.
Abstract: Dopamine (DA) is a neurotransmitter implicated in reward/motivational neurocircuitry which includes a primary pathway connecting the ventral tegmental area (VTA) and nucleus accumbens (NAc). Prior studies have revealed that dopaminergic VTA neurons projecting to the NAc are implicated in cue-response behavior in humans and rats. Microdialysis rodent studies have shown that the administration of an amino acid mixture lacking tyrosine (and its precursor, phenylalanine) (Tyr/Phe-) results in temporary depletion of tonic DA in the NAc. This study tested the effectiveness of the Tyr/Phe- mixture on phasic DA transient activity in same brain region. We hypothesized that the Tyr/Phe- mixture would decrease the frequency and amplitude of spontaneous DA transients in the NAc of rats while a control mixture containing tyrosine and phenylalanine (Tyr+/Phe+) would have no effect on spontaneous DA release. We used fast scan cyclic voltammetry (FSCV) to measure spontaneous DA transients release in the NAc of rats at baseline and after injection of the Tyr/Phe- or Tyr+/Phe+ mixture. We found that administration of the Try/Phe- mixture led to a decrease in both the number and amplitude of DA transients while administration of the Tyr+/Phe+ mixture had no effect of frequency of DA transients. The verification of the mixture?s effectiveness in rats allows further studies to be conducted on role of DA in cue-response behavior in both rats and human subjects.
Faculty/Postdoc Contributors: David Pfennig
Abstract: Coral snakes and their mimics often have brightly colored banded patterns, generally associated with warning coloration or mimicry. However, these color patterns have also been hypothesized to aid snakes in escaping predators through a ?flicker-fusion? effect. According to this hypothesis, banded color patterns confuse potential predators when a snake transitions from resting to moving because its bands blur together to form a different color. To produce this motion blur, a moving snake?s bands must transition faster than the critical flicker-fusion rate at which a predator?s photoreceptors can refresh. It is unknown if coral snakes or their mimics meet this requirement. We tested this hypothesis by measuring the movement speed and color patterns of two coral snake mimics, Lampropeltis triangulum campbelli and L. elapsoides, and comparing the frequency of color transitions to the photoreceptor activity of the avian eye. We found that snakes frequently produced a motion blur, but moving snakes created a blurring effect more often in darker conditions, such as sunrise, sunset, and nighttime when these snakes are most active. Thus, at least two species of coral snake mimics are capable of achieving flicker-fusion, indicating that their color patterns may confer an additional defense aside from mimicry.
Abstract: Among women in the United States, breast cancer is the most commonly diagnosed cancer and the second leading cause of death. During breast tumor progression, the surrounding breast tissue, largely composed of adipose tissue, becomes hardened and fibrotic, promoting inflammation and angiogenesis in tumors. However, the origin of the fibroblasts, major stromal support cells, remains uncertain. My hypothesis to explain the increase in fibrotic tissue and the decrease in adipose tissue is that the adipocytes de-differentiate into fibroblasts. I have isolated mature adipocytes from mouse mammary fat pads and performed in vitro characterization of these cells. The morphology and adipocyte and fibroblast gene expression are compared before and after co-culture with tumor cells. To track the fate of the adipocytes in vivo during tumor growth, Adipoq-cre mice are crossed with ZS-green reporter mice to produce Zs-greenAdi-cre mice whose mature adipocytes are tagged with the fluorescent protein ZS-green. I have optimized a mammary tumor spheroid model that accurately represents clinical tumor growth for injection into the mammary fat pads of the Zs-greenAdi-cre reporter mice. Tumor-associated adipose tissue will be harvested and the gene expression and morphology will be compared to normal adipose tissue. Determining the origin of tumor-associated fibroblasts will offer potential means of cancer therapy by targeting stromal support cells.
Abstract: Glial cells that reside at the midline of the fruit fly Drosophila melanogaster?s central nervous system (CNS) have many important functions, including guiding and supporting neurons. Studying Drosophila midline glia will inform research on vertebrate nervous system development, because Drosophila glia are in many ways similar to glial cells in vertebrates. Since numerous D. melanogaster genes are related to those in humans, knowledge of fly gene functions may be applied to the study of human genetic disorders. Some mutant fly strains have altered midline glial development, including defects in midline glial migration and wrapping neurons. Mutant flies may have glial cells that have moved to the wrong location, or have unprotected neurons that are not properly covered by glia. My research was focused on identifying the genes that are affected in these mutants, then finding out what roles these genes have in midline glial development. My genes of interest were CG9336, CG14968, Cpr78Cb, and tap. All of these genes are expressed in midline glia, except tap, which is expressed in midline cells adjacent to the glia. Essentially, the goal of the work is to test whether these four genes are required for midline development, such that the loss of the genes cause the mutant phenotypes. My question for this ongoing project: How do these genes and their protein products function, and how are they responsible for the correct development of Drosophila midline glia?
Faculty/Postdoc Contributors: Shawn Ahmed
Abstract: After multiple cellular divisions, uncapped, critically shortened telomeres are often healed by end-to-end chromosome fusions, genome rearrangements commonly found in tumors. Previously, breakage-fusion-bridge (BFB) cycles have been the sole model for the generation of chromosome fusions. This study attempts to further validate a telomere repair mechanism in Caenorhabditis elegans, the Fork Stalling and Template Switching model (FoSTeS) that results in shortened, uncapped telomeres invading interstitial telomere sequences followed by promiscuous DNA synthesis. This model may explain the multiple inverted DNA repeats found between fused chromosomes. This method has been applied to the first interstitial telomere sequence (ITS) on the right arm of the X chromosome (XR-1) in telomerase reverse transcriptase deficient mutant strains (trt-1 mutants), as ITS-telomere recombination events indicate fusion and have consistently been found using polymerase chain reaction (PCR) analysis. The results of this study support the FoSTeS model by showing that interstitial telomere sequences on the left arm of the second chromosome also exhibit these recombination events.
Abstract: Adrenergic alpha 2A receptors (ADRA2A) are known to play an important role in descending pain pathways and in the generation of stress-induced analgesia. However, the influence of ADRA2A genetic variants on acute pain severity after motor vehicle collision (MVC) has not been assessed. In this study we hypothesized that a genetic variant in the 3?UTR of ADRA2A, rs3750625, affects acute pain outcomes by determining the binding efficiency of a pain-related microRNA, miR-34a. The association between rs3750625 allele and acute post-MVC pain outcomes was assessed using a study of 948 European Americans who presented to the emergency department (ED) for evaluation after MVC. The rs3750625 genotype was determined from patient blood ED samples. miRNA binding was assessed using a luciferase reporter assay consisting of a miR-34a expression cassette and individual ADRA2A 3?UTR-luc reporters with either the minor or major allele. In regression models adjusted for age, sex, and study site, the minor allele (A) of rs3750625 was associated with greater ED pain severity and more body regions of pain. Luciferase reporter assays demonstrated that miR-34a binds the 3?UTR of ADRA2A and that the amount of knock-down is significantly more efficient when the minor allele is present. These results suggest that genetic variant rs3750625 in the 3?UTR of ADRA2A affects individual vulnerability to acute pain after traumatic events such as MVC, and that this influence may be mediated by miRNA binding.
Abstract: Our Goal is to develop a new series of catalytic initiators of cascading cyclization of poly-olefins into fused-ring structures. Efficient synthesis of functionalized fused-ring molecules could lead to the creation of steroid and hormone-type treatments for pharmaceutical use. We are exploring the use of platinum complexes and attempting to develop a catalyst that is capable of turnover in the presence of mild one-electron reductants.
Abstract: AMP-activated protein kinase (AMPK), a sensor for the cell's energy status, detects changes in cellular AMP:ATP and ADP:ATP levels. When the ATP concentration is low, AMPK turns on catabolic pathways and turns off anabolic pathways. AMPK is a proposed therapeutic target for a number of diseases, for example, diabetes. In my research, I examine the signaling pathway between AMPK and the mammalian target of rapamycin complex 1 (mTORC1) in autophagy. AMPK inhibits mTORC1's activity. A method to test this activity is through Western blot analysis of S6 kinase because mTORC1 phosphorylates and activates S6 kinase. In addition, a possible subsequent relationship between mTORC1 and the transient receptor potential mucolipin-1 (TRPML1) is examined. TRPML1 plays an important role in autophagy and is required for the completion of autophagy. Loss-of-function TRPML1 leads to a lysosomal storage disorder (LSD). My hypothesis is that mTORC1 directly interacts with and regulates TRPML1 activity, thereby forming an additional mechanism of feedback during the autophagy process that may also compensate for the loss of AMPK activity. Using Drosophila as a genetic tool, the relationship between AMPK, mTORC1, and TRPML1 is examined using AMPK alpha-RNAi, TRPML1-RNAi, AMPK alpha loss-of-function alleles, and TRPML1 loss-of-function alleles and yeast-fed and starved flies.
Abstract: The investigation of direct acid reduction is an essential requirement in order to better understand and represent the effectiveness of organometallic catalysts that serve to evolve hydrogen from aqueous solutions. Utilizing a combination of metal-derived catalysts and electrical stimulation to evolve hydrogen from an acidic system has the potential to provide insight in the production of hydrogen, an attractively clean fuel. The means by which this is approached requires a variety of synthetic and electrochemical techniques. Cyclic voltammetry was the primary technique in analyzing these complexes. Preliminary electrochemical data revealed, however, a potential source of error previously uninvestigated and unaccounted for that skewed quantitative results. As such, the effect of direct acid reduction on glassy carbon electrodes was evaluated such that future catalytic studies can account for alternative sources of error.
Abstract: Membrane proteins are molecules existing within and/or anchored to biological membranes, such as that of a cell or organelle. These proteins act as cellular receptors and transporters, making them particularly significant to the medical and pharmaceutical fields. However, these proteins are difficult to analyze due to their insolubility with traditional solvents and instability outside of a biological membrane environment. Therefore, this research focused on the development of specialized extraction, purification, and digestion techniques required for membrane protein identification. The application of various solvents and detergents were tested to improve solubility, as well as multiple purification techniques to successfully extract and isolate membrane proteins from their native environment. Optimized conditions were selected for each step of the analysis. First intact proteins were separated using high-pressure liquid chromatography and the resulting fractions collected were enzymatically digested. The resulting peptides were then separated via ultra-high pressure liquid chromatography coupled with mass spectrometry and the resulting spectra were used to identify the proteins present. It was found that utilizing sonication throughout the process, along with various solvents and detergents, resulted in an increased number of membrane protein identifications.
Abstract: Neisseria Gonorrhoeae is the strain of bacteria that causes the sexually transmitted infection, gonorrhea. The infection has been difficult to treat due to the bacteria's ability to go undetected by the immune system as well as develop resistance to many antibiotics that have been used to treat the infection in the past. The LpxK protein, investigated in this project, is a membrane-associated lipid kinase involved in an essential lipid A biosynthetic pathway which is highly conserved across nearly all Gram-negative bacteria, including N. Gonorrhoeae, and a pathway that has not been previously studied as a target for antibiotics. If LpxK is determined to be essential for the perpetuation of N. Gonorrhoeae, it can begin to serve as a reliable target for antibiotics to kill the bacteria and lead to a novel, penetrative treatment of the infection.
Abstract: Vinculin is an essential cytoskeletal protein present in focal adhesions and cell-cell adhesions that plays an important role in cell adhesion, motility, and force transmission, by binding to multiple ligands. The interaction between the tail domain of vinculin (Vt) and the phospholipid, phosphatidylinositol 4,5-bisphosphate (PIP?2) at the cell membrane is thought to have an important role in PIP2 signaling, a pathway significant in cell movement. This study sought to determine the specific residues involved in PIP2 binding by lipid co-sedimentation assays and to develop a PIP?2-bound vinculin structure by x-ray crystallography. Three residues in Vt were identified as having a critical role in PIP2 binding. Vinculin variants containing mutations of these residues were tested in lipid binding and co-sedimentation assays with PIP2-containing liposomes and were found to significantly disrupt binding and membrane insertion of vinculin. To date, x-ray crystallography of these variants has not yielded a conclusive structure. Optimal conditions for crystal growth are currently being studied to develop larger crystals that will yield brighter x-ray diffraction patterns and a conclusive structure.
Abstract: The existence of operational inefficiency in the U.S. airline industry, combined with rising costs and financial problems, has long prompted airlines to find ways to consolidate through mergers, and to cooperate through codeshare agreements and alliances. While the price and competition effects of mergers and codeshare agreements are well documented by existing research, there is comparatively little literature over a merger?s impact on the codeshare products between the merging firms, and on markets abundant in codeshare passengers. This paper seeks to fill this research gap by analyzing price data for 75 million passengers, aggregated into 75,000 products and 50,000 markets, from four consecutive quarters before and four consecutive quarters after the United-Continental Airline merger. After accounting for changes in market demographics, cost of fuel, market concentration, and industry-wide prices, the results indicate a statistically significant price increase in formerly codeshare products, which is especially pronounced in markets with lower market concentration. The results also indicate a positive relationship between the proportion of codeshare passengers and market prices. In light of the extensive airline consolidation in recent years, and the fact that over one-third of passengers fly on codeshare tickets, these findings can help inform policy-makers in making decisions concerning mergers, as well as in overseeing future codeshare agreements and alliances.
Abstract: The human health threat posed by multi-drug resistant bacteria necessitates an understanding of the mechanisms underlying the spread of this resistance. Bacteria can propagate genes encoding antibiotic resistance through a process known as conjugative plasmid transfer (CPT). To initiate CPT, conjugative proteins assemble into the relaxosome, a multi-protein complex necessary for sequence-specific plasmid transfer. The relaxase, a component of the relaxosome, nicks DNA at the plasmid origin of transfer (oriT) and a helicase subsequently unwinds the DNA for cell-to-cell transfer. In Salmonella typhimurium plasmid pCU1, the conjugative protein TraK is hypothesized help form the relaxosome and play a central role in binding and stabilizing DNA. TraK oligomerization and site-specific binding affinity to the pCU1 oriT were analyzed through atomic force microscopy and fluorescence-anisotropy based DNA binding assays. We found that TraK primarily exists in a tetramer-dimer equilibrium and weakly binds to multiple regions of the pCU1 oriT. Further assessments are currently underway to elucidate TraK structure as well as its specificity and mechanism of DNA binding essential for CPT.
Abstract: The academic and social impacts of fraternal organizations on college campuses have become a topic of more fervent debate in recent years. Recruitment websites for Greek life often claim that fraternity and sorority members achieve greater levels of campus involvement and academic success. Contrastingly, critics of the Greek system point to reputed negative social impacts, including contributions to rape culture, dangerous hazing of new initiates, and incidences of alcohol poisoning, and common media stereotypes to refute these claims. Using data from the National Longitudinal Survey of Freshmen (NLSF), this paper investigates the effect of participating in a Greek organization on academic outcomes for students at fairly selective postsecondary institutions, namely grade point average (GPA) and graduation rates. Employing propensity score matching (PSM) with a nearest neighbor caliper method allowed for the resampling of survey data to account for self-selection bias into fraternities and sororities. Following PSM, ordinary least squares and probit regressions were used to determine the effect of participation in Greek organization on GPA and graduation rates. A negative relationship was found between Greek membership and cumulative GPA of roughly half of one letter mark (0.15 GPA points on a 4.0 scale), though participation in the Greek system is correlated to an increased chance of graduating within four years and within six years.
Abstract: Traditionally in a public goods model, individuals decide whether or not to contribute to the good based off of the actions of their neighbors, and a pre-determined payoff parameter that will tend to be uniform for all actors in the network. This decision-making process for an individual actor to contribute to a public good has historically been instrumental in providing the theoretical framework for the conservation of public goods. In this study, an existing popular proposition in the literature claiming that if the absolute value of the minimum eigenvalue of the adjacency matrix is less than the inverse of the payoff parameter, then there is a unique Nash equilibria, is tested. In this process, the condition that one payoff parameter must be utilized for all the agents in the network is relaxed, and is tested on two randomized network models: the Erdős?R?nyi and Stochastic Block Models. Then, the existence of both unique and multiple Nash equilibria, and their location as interior solutions are explored in relation to the number and range of the different payoff parameters. While the final analysis is still in progress, it has become apparent that the number of Nash Equilibria notably increases once the payoff parameters in the network rise above a ?threshold? value.
Abstract: Although health care access in China has improved in the past thirty years, there are still problems for many potential patients in the population. Health care access is important for chronic diseases such as digestive diseases and cardiovascular diseases because knowing one?s diagnosis allows one to change habits that have been shown to decrease severity of disease. Using the China Health and Nutrition Survey, this study looks at the impact that different health care access factors have on a patient?s ability to get a diagnosis. It will also address whether that diagnosis will translate into a change of habits for the person in terms of nutrition and physical activity. The study will use simultaneous equations to investigate the effects at each stage. Previous literature has not looked at the ability to get a diagnosis or the diagnosis?s effect on a person?s habits. Further estimation is still required, but the current findings suggest that health care access does affect one?s ability to get a diagnosis.
Abstract: Although racial differences among NBA player salary have been studied extensively prior to 2000, the NBA has become more diverse in the last 15 years with an influx of international players. Many advanced performance statistics have also been introduced in the last decade. Therefore, exploring the influence that these new factors have on player salary will be useful to understand the important determinants of player salary. This study aims to extend existing literature by using player performance data from the 2012-13 season. The factors that influence salary are investigated by building upon existing econometric models with additional explanatory variables. In my research, the economic model being used to estimate salary is a function of a vector of explanatory variables. These include an indicator for race, performance statistics, and local market variables such as per capita income and population in metropolitan statistical areas. The dataset consisted of 468 observations, which encompassed all players in the NBA during the 2012-13 season. A Tobit regression was performed to estimate the salary model because the dependent variable is non-negative and truncated at the NBA?s minimum player salary. As such, 62 observations were left censored. The results indicated that significantly positive influences on salary include race, age, position, and minutes played. Significantly negative influences on salary are personal fouls and population in a metropolitan statistical area.
Abstract: Traditional economic theory suggests that decision makers should not allow sunk costs to shape future actions. However, empirical studies have found a commensurate relationship between sunk costs and future expenditures when expected marginal costs exceed expected marginal benefits, an idea referred to as the ?escalation of commitment.? With large sunk costs annually incurred through player drafts, executives in the high-stakes business of professional sports may be particularly prone to the escalation of commitment. This research will specifically examine the National Basketball Association (NBA), evaluate teams? personnel decisions and determine the prevalence of escalation of commitment in the league. Previous studies on this topic have not utilized the most accurate performance measures, have not been updated through the recent Collective Bargaining Agreements (CBAs) and have not fully encompassed the theoretical literature. This study anticipates that a careful consideration of the latest theory and improved models will lead to less escalation of commitment than what has been found in previous studies. In effect, this study anticipates finding more rational behavior among NBA decision makers. Early estimation shows that escalation is lower in magnitude and shorter in duration than in previous studies.
Abstract: While China experienced rapid economic growth in the past decade, development of health care lagged in comparison. After the collapse of the previous insurance system in the late 1970s, a New Rural Cooperative Medical System was implemented in 2003 to continue healthcare support for rural households. Although research has been done to assess the outcome of the program, limited studies have been done to analyzed the decision-making factors by rural consumers. This study aims to investigate the impact of healthcare access on insurance participation rate. The data for this study will be extracted from the China Nutrition and Health survey, a longitudinal dataset collected by Carolina Population Center at UNC. Probit regressions will be utilized to identify the relationships and to take account of other control variables. Preliminary result shows that the cost of travelling is not statistically significant; however, the travel time to a medical facility decreases the probability to have insurance. On the other hand, the availability of necessary medicine increases the participation rate. Other factors, such as level of education, income and presence of chronic illness, also increase the probability to have insurance. Although additional modifications to the model and data management technique will be determined, the preliminary results indicate that improving access to healthcare should be integrated as a part of the new system to maximize insurance coverage.
Abstract: This paper explores the intergenerational socioeconomic consequences of incarceration. Through a structural equation model with latent variables, it analyzes four waves of data from the National Longitudinal Study of Adolescent Health to explore how paternal incarceration influences children?s school success and early labor market outcomes. Paternal incarceration affects children?s performance in school through decreased family earnings, reduced parental involvement, and worse mental health. It also negatively affects their school performance directly. These educational consequences play out in young adulthood through decreased chance of earning a high school degree, reduced earnings, and increased chance of unemployment. Punishment in America reverberates across generations. The findings suggest that mass incarceration may partly explain low rates of socioeconomic mobility in the United States.
Abstract: Introduction- Cardiovascular disease is the leading cause of death in India. Accessibility to healthcare is particularly limited in rural India. Telemedicine utilizing a smartphone application may be a useful screening tool in rural areas. Methods- Patients seeking medical care at several rural villages outside of Pune, India were screened for dysrhythmia using a smart phone application (AliveCor, San Francisco, CA). A single-lead ECG was transmitted remotely to an expert cardiologist (University of North Carolina) and assessed within 24 hours. For any ECG abnormality identified, the patient was contacted and provided with a referral to receive follow-up care. Results- During one month (July, 2013), 221 patients were screened. The mean (SD) age of the cohort was 35.0 (14.4) years and 71.8% were male. Comorbidities included hypertension (4.5%), diabetes (10.9%), and smoking (36.4%). On cardiac review of symptoms, 14.5% of patients had chest pain, 2.3% lightheadedness, 2.7% syncope, 5.9% palpitations and 8.2% dizziness. Of the 221 patients, 219 (99%) had ECGs taken with a clearly interpretable rhythm (Figure). Of the 219 patients, 4 were recommended for follow-up care. One of these 4 had atrial flutter and the other 3 had sinus tachycardia. Conclusion- AliveCor provides a high quality single-lead ECG that can be rapidly transmitted and interpreted. A smartphone ECG is feasible as a screening device to provide early identification of potential cardiac illness.
Abstract: This paper examines the portfolio response to scheduled macroeconomic news events using both daily and high frequency data. This is accomplished by comparing Sharpe ratios of portfolios formed using naive forecasting methods for expected return and volatility with those formed using ex ante knowledge of the release value as an additional term in the conditional mean and conditional variance equations. For tractability, the unconditional covariance is used to forecast the covariances required in Modern Portfolio Theory. The workhorse Autoregressive (AR(1)) and Generalized Autoregressive Conditional Heteroscedasticity (GARCH(1,1)) models are used to forecast expected return and variance respectively. The hypothetical portfolio is created at the end of the period before the release, and sold at the end of the period of the release. This paper finds that from the time period 2003-2012, there is little evidence to support the claim that knowledge of the release value improves portfolio performance. It is concluded that, although macroeconomic news events do affect the assets studied, there is no way to systematically include knowledge of the release values into your portfolio.
Abstract: This research investigates the relationship between EU Emission Allowance price changes and the stock performance of European electricity firms. The EU Emission Trading Scheme (ETS) began in 2005 as a cap and trade model to help meet the binding carbon emission reduction obligations set by the Kyoto Protocol. An existing study in the literature used a multifactor model which included the return of the market, the change in electricity prices, the change in oil prices, and the change in EU Emission Allowance prices as factors determining the return of individual European electricity firms from 2006-2009. My research uses this multifactor model for 2010-2012 data to see if the increased development and strictness of the ETS has caused a change in the relationship between the price developments of the carbon allowances and the stock return of European electricity firms. I also use a modified multifactor model which includes the country the electricity firms are headquartered as a significant variable?this is included due to the decentralized structure of the ETS. If investors believe that the added cost imposed on electricity firms for having to purchase carbon allowances is able to be passed onto consumers then a positive correlation is expected between the variables studied.
Abstract: Most of the economic and sociological literature on the outcomes of children of immigrants uses income or years of education to measure the extent to which human capital is transferred from parent to child. This paper examines the role of parent human capital and levels of ethnic community human capital in predicting participation in science, technology, engineering, and mathematics (STEM) fields. This paper finds that parent human capital strongly predicts child participation in these fields. Ethnic community characteristics produce a weaker effect, but their effects are mitigated when controlling for neighborhood and source country characteristics.
Abstract: My project examines the Digital Humanities and its place in the modern higher-level literature classroom. I take a critical look at cyber theory in practice and whether or not it upholds the transformative goals of early digital humanists, including: decentralization in learning, greater student-based production of knowledge, and collaboration. By examining the successes and failures of multiple case studies grounded in the use of digital tools, and by observing, first-hand, an undergraduate class at UNC that engages with digital tools, I hope to highlight the value of this emerging literary field, which, I argue, lies in its potential to level the hierarchical structure of academia, and alter the way in which we view the literary process itself. Rather than using these tools to simply supplement a traditional textual interpretation, how might the Digital Humanities dismantle this tradition in a meaningful way? What is lost and gained in this transition? How can we use the Digital Humanities to engage with texts in a new and interesting manner? And, of course?.what is it??
Undergraduate Co-Authors: Christina Wall, Maida Salihovic
Abstract: Regardless of background, all individuals experience insecurities that plague their self-esteem. When anxieties intensify, they can manifest themselves as vultures, which subconsciously attack people when they are weakest. Through our research, we sought to determine if and to what extent vultures are transmitted through social media and how transmission correlates to self-concept. We utilized surveys to gauge our participants? vultures, analyzing the results in conjunction with their Facebook posts. Through observation, we found that vultures are palpable in online communications with such regularity that we were able to create a model illustrating specific types of vulture transmission. Through follow-up surveys, we also concluded that users are generally unaware of this transmission. This lack of awareness suggests several important implications regarding the nature of online communication. First, despite common assumptions that digital interactions lack the social cues present in face-to-face communication, online interaction is far richer than generally thought. Second, this lack of awareness is implicated in one?s identity management, as our research suggests that individuals are largely oblivious to the ways their vulture transmission affects their online personas. This deficiency in awareness and its impact on identity management also indicates that, in an age where online confidentiality is increasingly valued, people are unknowingly threatening their own privacy.
Abstract: I conducted this research the summer of 2013 with the help of a SURF grant. My project examines depictions of reproduction in the work of American writer Djuna Barnes, whose explorations of topics like polygamy, homosexuality, and maternal death have intrigued and perplexed readers since the early twentieth century. In my work I link Barnes's portrayals of physical reproduction to her allusive and imitative writing style, which utilizes a form of literary reproduction. I explore the manner in which both sexual and textual reproduction can be employed to either undermine or uphold dominant cultural ideologies. My research draws upon Barnes's four major works, as well as primary documents including her early drafts and personal correspondence.
Abstract: Rising atmospheric carbon dioxide concentrations will continue to cause mean global surface seawaters to increase in temperature and decrease in pH. Although previous experimental studies indicate that ocean warming and ocean acidification will continue to compromise coral calcification, uncertainty remains as to the effect of feeding on the skeletal growth response of corals. Indeed, the existing literature reports variable levels of feeding in laboratory-based experiments with few studies accounting for the ambient zooplankton concentration that corals experience in their natural environment. The lack of a standardized feeding metric across these experiments decreases the applicability of the findings and hinders efforts to better understand the calcification response of corals to climate change. The temperate scleractinian coral Oculina arbuscula is found throughout the coast of the mid-Atlantic and southeast United States. This species is considered facultatively symbiotic, existing in a range of forms from zooxanthellate to azooxanthellate. Therefore, O. arbuscula, as with all scleractinian corals, depends not only on photosynthesis of the algal symbiont, but also on heterotrophic feeding which provides nitrogen, phosphorus, and other nutrients not supplied by photosynthesis. Here, six colonies of O. arbuscula were collected at Radio Island in Beaufort, NC and transported to the University of North Carolina at Chapel Hill. Currently underway is a laboratory-based experiment in which four feeding treatments (zero, low, ambient and high) are used to quantify the effects of feeding newly hatched Artemia sp. nauplii on the skeletal growth of O. arbuscula at the current mean annual temperature of 20°C and at the predicted end-of-century summer temperature of 28°C using a buoyant weight method. Ambient zooplankton concentration for this region was determined using a value reported by Fulton (1984). The results of this study will reveal how feeding affects skeletal growth in this species, both under present day and predicted temperature conditions. Additionally, this study will highlight the need for a standardized feeding metric that will foster a more accurate interpretation of the effects of climate change on the calcification response of scleractinian corals.
Abstract: Diatoms are single-celled phytoplanktons that produce approximately 40 of the oxygen in the atmosphere. As they photosynthesize, die, and fall to the bottom of the ocean they also provide a significant carbon sink, further establishing their ecological and biogeochemical importance. In many regions of the ocean, the trace element iron limits the growth of diatoms. In this study, we examined the tolerance to low iron conditions among several diatoms originally isolated from coastal and oceanic environments, including iron-limited regions. The growth rates and photosynthetic efficiencies of the diatoms were measured through an assessment of changes in chlorophyll a fluorescence over time and variable fluorescence kinetics using a Fluorescence Induction and Relaxation (FIRe) fluorometer. Our findings suggest oceanic diatoms are much more tolerant of low iron conditions than their coastal diatom counterparts. In addition, although the oceanic centric diatom Thalasiosira oceanic is often used as a model low-iron tolerant species in iron limitation experiments, our findings suggests the oceanic pinnate diatom Pseduo-nitzchia granii is able to grow as much lower iron concentrations, suggesting further adaptations to coping with iron stress.
Abstract: The nutrient and vitamin concentrations in Earth?s oceans will likely change in the coming years due to global climate change caused by anthropogenic forcings. It is important to study how the changing environment will affect marine phytoplankton because they play an integral role in atmospheric carbon uptake through primary production. The purpose of this study was to determine how the phytoplankton community changes in the NE Pacific with the addition of iron (Fe) and vitamins (B12 and B7). Water samples were collected along the well-studied coastal to open ocean transect known as Line P, and seawater was spiked to create six different treatments: Fe, Fe and B7, Fe and B12, B12, B7, and a control group. The methods utilized in this study were light microscopy, 18S clone libraries, and flow cytometry. The light microscopy results indicate that with the addition of Fe, diatoms thrive and become the most abundant phytoplankton in the water samples. Using the Shannon Diversity Index, this study concludes that the overall diversity of the phytoplankton community decreases with time for all six treatment groups. The normalized diversity was highest in the control group after 96 hours but there was a negligible difference in diversity among the other five treatments. This indicates that the changing vitamin and Fe concentrations in the world?s oceans will have an effect on the overall biodiversity of phytoplankton communities in Fe limited regions of the NE Pacific.
Abstract: Light-absorbing organic carbon is an important climate warming agent that contributes to positive radiative forcing, but to date it is generally not represented in current climate models in part due to lack of understanding in its sources and formation processes. Secondary organic aerosol produced from heterogeneous reactive uptake of isoprene epoxydiols has been found to substantially contribute to the organic aerosol mass over the Southeast U.S. where SOA formation from isoprene is significantly enhanced by biogenic/anthropogenic interactions. Brown carbon in rural areas in this region has been reported to be associated with secondary sources in summer when influences from biomass burning are low. Chemical analyses of light-absorbing SOA constituents using diode array detection and mass spectrometric techniques indicate the formation of Isoprene-derived Brown Carbon is strongly associated with 3-methyltetrahydrofuran-3,4-diols, which are products of acid-catalyzed intramolecular rearrangement of isoprene-epoxydiols in the particle phase. Field observations of these conjugated oligomers from the rural southeast U.S. support the atmospheric relevance of this secondary Brown Carbon source. These results illustrate a previously unknown relationship between isoprene, the second most abundant atmospheric hydrocarbon, and the radiative budget with major implications for air quality and climate models.
Abstract: The North American Renewable and Neutral Energy Alliance (NARNEA) is a network of renewable energy power plants aimed at generating 400GW of electric power, thus eventually eliminating coal-powered electricity generation in North America at a cost of less than one trillion dollars over 15 years. We have researched the current renewable infrastructure to create a loose budget for the costs of this network. Our research indicates that this initial goal can be met using primarily thermal solar and geothermal energies. Biofuel from algae, hydropower, wind, and tidal resources complete our vision of the project. We expect that the public?s support will decidedly weigh on the governments of North America to fund the project in the near future. We believe that North America is the perfect place to apply such a grid because we have seen the United States, Mexico and Canada sign international agreements in the past, such as NAFTA. When this project starts to become a reality, it will create a huge job market for the construction of the new power plants as well as the long-term operating positions. NARNEA will help to stimulate the economy, mitigate negative public and environmental health issues, and help strengthen national security by promoting energy independence for North America. Those are the goals that have motivated us to do this research and fight for this idea, now we just need support.
Abstract: A one-time Core Stability Intervention Protocol will be put into place to determine whether such an exercise regimen elicits changes in reducing anterior pelvic tilt, trunk flexion, hip internal rotation, hip adduction, and knee valgum during dynamic movement. Twenty physically active individuals will have their lower extremity kinematics measured while performing two trials of five repetitions of the Overhead Squat Assessment separated by the Core Stability Intervention Protocol. Five paired samples T-tests will be utilized to analyze any significant changes in pre and post Core Stability Intervention Protocol. Significant changes may have implications for clinical use of such a Core Stability intervention for patients with Lower Back Pain.
Faculty/Postdoc Contributors: T Michell
Abstract: Athletic taping techniques have been identified as a way to prevent excessive foot pronation, which can cause overuse injuries including plantar fasciitis, medial tibial stress syndrome, and tendinitis. This study examines the effect of the Michell Arch Tape on lower extremity movements that are related to excessive pronation compared to no intervention. It is hypothesized that the arch taping will limit predictors of excessive pronation: knee internal rotation, medial knee displacement, and ankle frontal plane displacement. A randomized controlled trial was conducted. Subjects were selected based on a weight-bearing lunge task to identify subjects with limited ankle dorsiflexion. The Foot Posture Index-6 (FPI-6) was used to identify the amount of static pronation in each subject. Subjects (n=21) were randomized into a treatment (n=13) and control group (n=8). Three-dimensional lower extremity biomechanics were assessed before and after taping during a gait, overhead squat, and lunge task. There was no evidence to suggest that the taping intervention significantly limited predictors of pronation, including ankle eversion, knee internal rotation, and knee valgus, in any of the tasks. The FPI-6 score was not correlated with a reduction in pronation for the taping intervention group. The Michell arch taping technique may or may not be effective in reducing pronation.
Abstract: This study attempts to gain perspective from current women's rugby players on elevating club teams to the varsity level. USA Rugby, the governing body of all rugby organizations in the US, supports the elevation initiative and has invested time and resources to the cause, but the conversion rate remains low. By surveying current club student-leaders, I aim to determine whether the lack of progress is due to a lack of interest or a lack of awareness. For universities, elevating rugby to a varsity sport could be beneficial for Title IX compliance. For USA Rugby, this study could help to shape new strategies for elevating the sport if there is significant interest. Using Qualtrics software, a survey was distributed to the population of women?s rugby club student-leaders to gauge interest in and awareness of the NCAA sport elevation process. The data was cross-tabulated to analyze interest, awareness, perceived benefits and drawbacks of NCAA participation and club teams? goals and values. I predict that teams may feel stifled by NCAA regulations and may value the social camaraderie that the culture of rugby offers over the desire to hold varsity status. Conversely, many teams may be unaware of their ability to elevate to varsity status as there have not been effective marketing methods utilized to raise their awareness.
Abstract: Eccles? expectancy-value model explains that parental beliefs influence a variety of child outcomes, including sport involvement (e.g., Fredricks & Eccles, 2005). Perceptions of costs and benefits are central to this model, but of particular interest to sport are safety concerns, which warrant specific attention in the contact sport of youth football. Accordingly, the goal of this study was to examine associations between parent and child perceptions of football-related costs, benefits, safety, and child psychosocial outcomes. Guided by Eccles? model, we hypothesized that parent safety concerns would moderate relationships among parent cost/benefit perceptions, child cost/benefit perceptions, and child outcomes of sport motivation and enjoyment. Youth football parents (N = 105, M_age = 42) completed valid and reliable online assessments of study variables during the fall 2013 season. Though the data did not support the safety concerns moderation hypothesis, correlational analyses of perceived costs, perceived benefits, and football outcomes were consistent with the theoretical model. Further exploration showed parent and child safety concerns to mediate some model pathways. Of note, parent concerns for head safety were not associated with child cost/benefit perceptions or psychosocial outcomes. The results expand on this existing model of family sport socialization and provide valuable insight into current parental and child attitudes toward youth football safety.
Abstract: Objective: To determine whether or not wearing a functional knee brace during rehabilitation affects ankle mechanics in patients six months following ACL reconstruction surgery. Hypothesis: It was hypothesized that wearing a functional knee brace would increase vertical ground reaction force, decrease ankle range of motion, and increase ankle moments. Methods: Twenty adolescent patients who had undergone ACL reconstruction surgery were recruited for the study. All subjects were assessed through motion analysis for a stop jump task. Subjects first completed the task while wearing an extension-limiting functional knee brace on the surgical limb and then without wearing the brace. For all subjects, data were collected six months following ACL reconstruction surgery. Results: There were no significant differences observed between the braced and non-braced conditions. Conclusions: Functional knee bracing seems to have no effect on the mechanics of the ankle on the surgical side.
Abstract: Purpose: This study assessed the influence of estrogen (E2) on skeletal muscle creatine kinase (CK) and cardiac muscle CK (CK-MB) responses to prolonged aerobic exercise. Elevations in these biomarkers are indicative of muscle trauma-damage. Methods: Eumenorrheic women (n=10) who were physically active completed two 60-minute treadmill running sessions at 65% maximal intensity during low E2 (midfollicular menstrual phase) and high E2 (midluteal menstrual phase) hormonal conditions. Blood samples were collected prior to exercise, following supine rest, immediately post-, 30 min post-, and 24 hr post-exercise to determine changes in muscle biomarker. Resting blood samples confirmed appropriate E2 hormonal levels Results: CK concentrations increased following exercise and at 24 hr post-exercise were higher in the midfollicular phase (p<0.001). However, CK-MB concentrations were unaffected by E2 level or exercise (p=0.442). Conclusions: E2 levels influence the CK biomarkers response for skeletal but not cardiac muscle following prolonged aerobic exercise. These findings imply elevated E2 is protective of skeletal muscle from exercise-induced damage.
Abstract: Understanding glacier volume and ice thickness is very important for many glaciological studies, yet it is difficult to obtain this information from direct measurement. This research presents an application of a new method that utilizes satellite surface velocity and thinning rates to produce a model of the bed topography. By using an estimate of ice flux to solve the continuity equation between adjacent glacier flowlines, we calculate ice thickness across the entire glacier. We then produce a model of the bed topography beneath the glacier using this ice thickness. This study is conducted on the Taku Glacier, a tidewater glacier on the Juneau Icefield in Southeast Alaska, which provides a unique opportunity to test this method on a large advancing glacier. By considering the calculated bedrock slopes and how thickness change propagates through a glacier, we can also then examine the stability of the Taku Glacier?s current advance.
Abstract: From the research so far, it appears that the editorial reactions from the Jewish papers regarding American participation in the 1936 Olympic Games focused not on the persecution of Jews in Nazi Germany, but on the debates among Americans and within the American sport organizations concerning participation in the Games. It is clear that the editors of the Jewish papers used in this study were aware of the situation for Jews in Germany. While specific events in Germany such as the passage of the Nuremburg Laws caused the editors of these three Jewish papers to react in uproars, the editorials and letters to the editor focused more on the events themselves and did not relate them to the Games. The strongest editorial reactions in these papers targeted the decisions made by Avery Brundage, the American Olympic Committee, and the Amateur Athletic Union. Editorials were generally published in the weeks leading up to meetings of these organizations and reactions were posted shortly thereafter. In the summer of 1935, reactions to the upcoming meeting started earlier than usual, and editorials were more frequent, most likely due to the realization that this was the last chance to change the course of events.
Abstract: Density, extension, and calcification have been regarded as some of the most useful measurements for calculating coral growth, which changes with and, thus, can be used as a record of past climate changes. Therefore, it is important to use the most precise and advanced image technology when taking these measurements. Whereas most studies of coral growth have relied on annual growth measurements extracted from x-ray images relying on heavy front end calibration, the recent utilization of CT scans for coral cores has opened new possibilities for speed, accuracy and, through RunningcoralGUI and OsiriX, the ability to extract semi-annual growth measurements from any cross sectional slice of the core. Having the freedom to ?slice? a coral core not only provides a more exact evaluation of coral growth, but will also allow the user to select the clearest cross section of the core for analysis. We stress the importance of taking advantage of the CT scan image technology in the study of coral growth to gain faster, more detailed, and more accurate measurements.
Abstract: Previous tomography in the southern Appalachians by Wagner et al. (2012) reveals a deviation in the expected Mohorovicic discontinuity, raising questions of what material is convoluting the crust-mantle boundary. The work presented here seeks to resolve the two models presented in that paper through gravity modelling along two transects in the same area. The Bouguer gravity anomaly for the surrounding eight states was tested against surficial geology, elevation, and crustal thickness to test if any of these variables control the anomaly. Results from the cross-sections are inconclusive, since these new gravity models can reasonably support the possibility of a dense eclogite root at 40 to 60km depth or a homogenous mantle. However, in all models, a sharp increase in overall crustal thickness seems to be required underneath the valley and ridge province of the southern Appalachians. This thickening can be attributed to one of the three orogenies that built this mountain belt, but the presence of an extensive eclogite slab cannot be proven with gravity modelling.
Abstract: The mineralogy and petrology of Parsa, an EH4 enstatite chondrite, was analyzed with an emphasis on the rare mineral roedderite (K,Na)2(Mg,Fe)5Si12O30) using an SEM, a JEOL Hyperprobe, and a Raman spectrometer. The dominant minerals in Parsa include enstatite (Mg2Si2O6), kamacite (Fe-Ni alloy, >90 wt% Fe), and troilite (FeS), indicating formation under highly reducing conditions. Secondary minerals include taenite (Fe-Ni alloy, >20 wt% Ni) albite (NaAlSi3O8), quartz (SiO2), daubreelite (FeCr2S4), caswellsilverite (NaCrS2), and roedderite. The minerals are fragmented, creating a brecciated texture, with only the primary minerals forming crystals >0.5 mm. All minerals are surrounded by FeO(OH), a weathering product of iron-containing minerals, likely in the goethite phase. Both kamacite and taenite contain up to 15 wt% silicon, with more partitioned into taenite. The kamacite has quartz inclusions; the taenite does not. The strong exsolution of iron and nickel indicates a slow cooling history. Roedderite occurs as elongated euhedral crystals, commonly as inclusions in troilite. All crystals are <15 microns across. K and Na typically occur in a 1:1 atomic ratio with no apparent zoning. Roedderite contained within troilite typically forms euhedral-subhedral, unbrecciated prisms with aspect ratios of ~5; roedderite crystals surrounded by brecciated silicates are typically anhedral. This difference in morphology may reflect differences in the physical properties of the minerals.
Undergraduate Co-Authors: N/A
Graduate Student Contributors: N/A
Faculty/Postdoc Contributors: N/A
Abstract: Cyclic variations in global climate can impact the stratigraphic record by: (1) causing expansions and contractions in ice sheet volume, which in turn cause cyclic variations in global sea level (eustasy) (2) causing cyclic changes in the width and position of Earth?s climate belts. The cyclic changes in the width and position of climate belts triggered changes in precipitation rates which lead to cyclic variations in sediment supply/discharge in the drainage basins of terrestrial fluvial systems. . The experiment is completed by comparing the synthetic stratigraphic sections to the stratigraphic record measured in the field in an area of southeastern Kentucky that contains Pennsylvanian age strata. The goodness of fit of the synthetic stratigraphic sections to the measured stratigraphic sections will reveal which sets of conditions were responsible for influencing deposition in the Appalachian Basin during the Pennsylvanian Period. Results should yield insight into Earth?s response to the last time that global climate made the transition from ice house conditions, similar to modern times, to the green house conditions of the future.
Abstract: The Deep River Basin in central North Carolina is one of a series of Triassic rift basins along the east coast called the Newark Supergroup. Although the east coast lies on a passive plate margin, there is recorded seismicity within all of the coastal states. However, this seismicity is conspicuously absent around the Deep River Basin and most of North Carolina east of the Appalachian Mountains. In March 2012 we installed a 12 station broadband seismic network surrounding the Sanford Sub-Basin of the Deep River Basin to measure previously unrecorded seismicity. Through fifteen months of data collection, we have confidently detected and located more than 160 low magnitude seismic events within the array. However, the event locations cluster in four locations - three of which are near local rock quarries and one is near an unidentified anthropic feature. Further, these events consistently occur between the hours of 9am and 6pm local time, Monday through Friday indicating that they are anthropogenic. The Deep River Basin is one of the most likely places east of the Appalachian Mountains in North Carolina to be seismically active, yet we have measured no natural seismicity. Additionally, using the recorded blasts as known sources, we have confirmed the effectiveness of our velocity model in locating local hypocenters within 2km of error.
Abstract: Background: Recreational waters can be contaminated by pathogens found in the fecal matter of humans and animals. These pathogens can cause gastrointestinal illness at a very low doses and it is difficult and costly to detect these pathogens in recreational waters. Therefore, indicator organisms that are abundant in the intestinal tracts of humans and animals are used as surrogates to indicate potential fecal contamination. Male-specific (F+) coliphages are viruses that infect E.coli and are used as viral indicators because they are morphologically and functionally similar to enteric virus, prevalent in wastewater and the intestinal tracts of humans and animals. EPA Method 1601 is a standard method used for detecting coliphages in water. However, the current method does not include divalent cations in spot plates, which are hypothesized to facilitate coliphage attachment and/or nucleic acid transfer to E.coli hosts. To test this hypothesis, MgCl2 or CaCl2 were added to spot plates as divalent cations and results were compared to spot plates with no divalent cations. Method: A total of 165 seawater samples were analyzed with EPA Method 1601. Samples were analyzed with spot plates containing no divalent cations, 0.01M MgCl2, 0.02M, 0.01M, and 0.002M CaCl2. Results: Among all spot plate divalent cations conditions tested, 0.01M MgCl2 had the highest level of coliphage detection, followed by 0.01M, 0.002M and 0.02M CaCl2 and lastly no divalent cation. Conclusions: Adding MgCl2 or CaCl2 as divalent cations to spot plates significantly increased F+ coliphage detection. Spot plates with MgCl2 had the highest level of detection. EPA Method 1601 should be revised to include divalent cations in spot plates for improved F+ coliphage detection.
Abstract: A theory presents an inclusive framework for discussing how and why several variables may be interrelated. Formal theoretical models are developed and used to inform smoking cessation interventions. The current study seeks to review theoretical models of smoking cessation, including both established tobacco methods and methods informed from other addictions and academic disciplines. A literature search of several online databases was completed to determine the most frequently used theories and to identify gaps in the literature as avenues for future research.
Abstract: This research investigated the development and growth of online gaymer communities by analyzing archived posts on gayming sites, UseNet, and through interviews with gaymers. Groups of gaymers began to form online in the 1990s but did not coalesce into major sites until the 2000s. In addition to a desire to network and play with like-minded individuals, gaymer communities formed to resist rampant homophobia and sexism in mainstream gaming communities. In addition to the homophobia of gamers, anti-harassment policies of game companies, which often either failed to prevent harassment or denied gaymer?s the ability to express their LGBT identity, shaped gaymer?s decisions to identify as LGBT in their game environments and profiles. As gaymer?s visibility increased, representations of LGBT characters and themes in both major video game titles and independent titles increased as well. By 2013, the gayming community had grown large enough to support multiple major communities, to fracture and have a cross-community dispute over the trademark on the term ?gaymer,? and to hold a major convention, GaymerX. There are also now out gay pro-gamers in e-sports, which is recognized by the United States government as a professional sport. Overall, in the past decade, the gaymer community has grown rapidly and its increase of visibility has shaped the policies of game companies and their products, which, in turn, have shaped the gayming community.
Abstract: My research question is, How have the tensions over how have tensions over racial equity in Chapel Hill-Carrboro City Schools evolved since the 1960s? Through oral histories, school board minutes, and newspaper records, I examined the discussion surrounding race during the desegregation era, the 1990s, and the 2000s. I found that since desegregation, the Chapel Hill-Carrboro Schools repeatedly promoted the status quo, in which white students were the most successful. National trends of individualism, meritocracy, and colorblindness have hindered the recognition of racism in Chapel Hill and equity in the schools. Only in moments when the school system acknowledged institutionalized racism did it move closer to racial equity. In the first chapter, I explore how desegregation of schools in Chapel Hill privileged the experiences and customs of white students and parents, laying the groundwork for later dissatisfaction. In the final two chapters, I describe how gifted programming was often a flashpoint for racial tension, as gifted classrooms were disproportionately white, and the efforts of school district administrators to correct resources imbalances between white and black students. A Summer Undergraduate Research Fellowship from the Office of Undergraduate Research at the University of North Carolina at Chapel Hill funded this research.
Abstract: The Kenya Emergency (1952-1960) was declared in response to an anticolonial rebellion involving disparate actors who were grouped by officials under the appellation ?Mau Mau.? The British and Kenyan governments brutally suppressed the rebellion in a sustained counterinsurgency. The Emergency caused tremendous social disruption: almost the entirety of Kenya?s Kikuyu population was interned or forcibly relocated. Throughout the campaign against Mau Mau, a liberal-paternalist rhetoric of ?rehabilitation? worked to conceal systematic violence and abuses. My project addresses the relationship between knowledge and the state in the British counterinsurgency efforts and examines the role played by postwar developmentalist thinking in British constructions of ?Mau Mau.? Many Europeans interpreted the rebellion as a regression into ?savage barbarism? and as a challenge to British efforts to create ?modern? Africans by means of development projects; some argued that it was the inevitable result of an encounter between ?primitive? and ?civilized? societies. A 1945 Sessional Paper had set as the general framework of the Kenyan Government ?to meet efficiently and expeditiously the complexity of post-war conditions and the primary problems of development and reconstruction.? I argue in part that this discourse of ?reconstruction? had a deep history in British imperial thinking since the First World War and helped determine the contours of the British reception of Mau Mau.
Abstract: The process of language learning involves acquiring an array of intricate patterns, both conscious and subconscious and in areas such as phonology and morphology. Pattern learning (or categorization) has long been studied in cognitive psychology and many experiments have investigated its effects in visual learning. However, the relatively complex process of pattern learning in language is not well understood. Fundamental questions of whether the same cognitive processes are used for non-linguistic and linguistic learning and how various factors may affect learning have yet to be answered. This study takes a preliminary look at these questions through a web-based experiment. Pilot tests investigated the relative salience of the chosen stimuli and the relative difficulty of morphological learning given various pattern structures.
Abstract: Languages have rules about which sounds can come next to other sounds within words. For example, in English, the word ?bnick? would not sound as good as the word ?blick?, even though neither is an actual word. This preference is a result of constraints in English. Hayes and White (2013) explored how well people learn natural and unnatural constraints in their language. Natural constraints are motivated by what sound combinations are physically easier to produce. If Language is an entirely learned skill, like riding a bike, then different types of rules in languages should be equally learnable. However, Hayes and White?s findings suggest that natural constraints could be learned more easily by speakers of English. This implies that there could be an innate bias causing people to prefer these particular rules. The current study seeks to explore other variables that might have contributed to Hayes and White?s findings besides the naturalness of their constraints. Past work in Linguistics and Psychology has shown that people learn simpler patterns better than they learn complex ones, even patterns that involve sound patterns in made-up languages (Shepherd et al 1961, Pycha et al 2003). Online experiments were used to test complexity as a factor that might be confounding Hayes and White?s findings. The results suggest that naturalness does people?s ability to learn real world sound patterns and that complexity does not.
Abstract: The concert ticket business consists of two players, the primary ticket seller and the scalpers. Ticketmaster is the dominant primary ticket seller. It has attempted several projects in hopes of breaking into the secondary market. In this research, we first investigate its merger with Live Nation, a concert promoting business. Many opposed the merger due to the combined company?s control of ticket sales and concert venues; however, the merger was approved by the U.S. Department of Justice in 2010. The word ?scalper? is usually associated with sketchy men standing outside venues selling tickets at exorbitant prices. Through the increasing presence of online ticketing, scalpers are now equipped with new technology. Consumers have to compete with ?ticket bots,? virtual robots programmed to buy up tickets to be sold at a higher price. The secondary ticket market is currently a four billion dollars a year business. The research in this project also examines the welfare effect of ticket resale under demand uncertainty. In our research, we model the ticket buyers, which include ticket scalpers and regular consumers, as a mixed distribution: scalpers are consumers whose valuation for the ticket coincides with its resale value. We compare the results with existing research that only model consumers without resale opportunity. After solving for the equilibrium of the ticket selling game, we will determine under which conditions should there be legal restrictions limiting ticket resale.
Abstract: This study investigates the relationship between women?s preconception health status and the health of the next generation. 49% of all pregnancies in the United States are unintended which presents a significant public health challenge as women often do not start necessary healthy practices until they find out about their pregnancies. Women?s health status during the preconception period is essential because the greatest effect of several risk factors that affect fetal development often occurs before women gain awareness of their pregnancies. In this study, pregnancy outcome variables include the way pregnancies ended, gestation, and birth weights of babies and women?s preconception health status is measured using general health status variables, Body Mass Index, and smoking regularity. The effect of women?s preconception health status on pregnancy outcomes is investigated by jointly estimating several equations simultaneously. This study uses data from all four waves of the National Longitudinal Study of Adolescent Health. Specifically, instead of using the responses at each wave, information in the survey was used to identify the timings of all births independent of the survey year. An annual data set is constructed with information on mothers? health multiple years prior to pregnancy. Although final results are pending further estimations, this new way of utilizing the data set allows a yearly hazard model of pregnancy.
Abstract: The purpose of ?A Tale of Two Classrooms: A Comparison of Female Students? Experiences in High School Mathematics Classrooms in China and the United States? was to analyze the environments of American and Chinese mathematics classrooms with a special focus on female students? attitudes, performance and perceived confidence towards mathematics. Through classroom observations and interviews, it was found that both countries had female students who responded less positively to mathematics than their male peers. The Chinese females were driven by the fierce competition of their education system while American females most often commented that they are more interested when mathematics has relevance with their long-term goals. Both nations? female students expressed a mutual increased interest in mathematics when the classroom dynamic is more conversational and open, as opposed to a setting in which a ?black-and-white? and right verses wrong approach to solving mathematics problems is taken.
Abstract: Prior research has found that mindfulness and attention are positively correlated, as are attention and time perception (Ruocco & Direkoglu, 2013; Mioni, Mattalia, & Stablum, 2013; Mullins, Bellgrove, Gill, & Robertson, 2005). A previous study also found that the measure of ?now? is longer for meditators than non-meditators (Sauer, Lemke, Wittmann, Kohls, Mochty, & Walach, 2012). The direct relationship between mindfulness and time perception was examined in the present study in order to find whether increased mindfulness is related to a longer and more accurate perception of time. Seventy undergraduate students at the University of North Carolina at Chapel Hill engaged in time perception tasks and self-reports of time perception and mindfulness. A positive relationship was found between trait mindfulness and self-reported time affluence that indicated that people higher in mindfulness felt ?wealthier? in time. Additionally, a positive trend was found between one time perception behavioral task and state mindfulness. As state mindfulness increased, Weighted Average Production times also increased. Findings supported a hypothesis that greater mindfulness is linked with more time affluence, and perhaps a longer perception of time, as well.
Abstract: A robust measure of decay and dispersion for the wave equation is provided by the localized energy estimates, which have been essential in proving, e.g. the Strichartz estimates on black hole backgrounds. We study localized energy estimates for the wave equation on 5D Myers-Perry space-times, which represent a family of rotating, axially symmetric, asymptotically flat black holes with spherical horizon topology and generalize the well-known Kerr space-times to higher dimensions. The Myers-Perry family is parameterized by two angular momentum parameters, which we assume to be sufficiently small relative to the mass of the black hole. This investigation is motivated by the nonlinear stability problem for the Kerr family of black holes, which may be easier to understand in higher dimensions. Typically, the localized energy estimates are proved by commuting the wave operator with a suitable first-order differential operator and integrating by parts. However, the underlying black hole geometry introduces a number of difficulties related to the trapping phenomenon, which is a known obstruction to dispersion and necessitates a loss in decay. On the Myers-Perry space-time, the nature of the trapped set is quite complicated in the sense that a single differential multiplier is insufficient to prove the desired result. As in the work of Tataru-Tohaneanu, we instead commute with an appropriate pseudodifferential operator to generate a positive commutator near the trapped set.
Abstract: Using a circularly polarized 30 MeV gamma ray beam at the High Intensity Gamma Source Facility at the Triangle University Nuclear Laboratory, the two-body photodisintegration of longitudinally polarized 3He will studied by measuring the spin-dependent asymmetry along with the differential and total cross sections. A highly pressurized 3He target will be used that is polarized via spin exchange optical pumping with alkali metals. The emitted protons from the photodisintegration will be detected using 72 silicon surface barrier detectors positioned in the reaction plane at 4 different angles between 45 and 120 degrees. The asymmetry and cross-section measurements will be used to test state-of-the-art three-body calculations and serve a more important goal of working towards determining the contribution of the two body threshold to the GDH pion production threshold.
Abstract: The Whitehurst lab utilizes a pan-genomic loss of function screening platform to identify novel genetic targets within malignancies that can be leveraged for potential clinical benefit. Through use of this platform the Whitehurst lab has previously identified a group of aberrantly expressed gametogneic genes that contribute to tumor cell viability and proliferation. These genes belong to a larger cohort referred to as Cancer-Testis Antigens (CTAs) that consists of genes whose expression is normally restricted to the testes and other gametogenic tissues, but that are also frequently expressed in tumors from a variety of cancer lineages. My work focuses on one member of this group FATE1 (Fetal and Adult Testes Expressed 1). Previous work has shown that FATE1 is necessary to maintain cell viability in H1155, a non-small cell lung cancer-derived cell line but is non-essential in immortalized human bronchial epithelial cells indicating a large potential therapeutic window. Preliminary work in the lab has demonstrated that FATE1 has an anti-apoptotic effect within malignant cells. Through the use of siRNA-mediated gene depletion I have shown that depletion of FATE1 leads to the induction of apoptosis and a long-term loss of cell viability in a number of cancer backgrounds. Future studies will investigate the role this interaction plays in the functional requirement of FATE1 within tumors and if this dependency is recapitulated in vivo using xenograft mouse models.
Abstract: Academic stereotypes can influence motivation and achievement negatively through stereotype threat and disidentification. In addition, traditional stereotypic beliefs may have a large impact on the development of a student?s self-concept and as a result, play a crucial role in academic identity development. Furthermore, parents influence the development of a child?s beliefs and judgments. Therefore, endorsement of traditional academic stereotypes by both parents and students may be detrimental to Black students and their development of a strong academic identity. I examined (1) the influence of parents? racial stereotype endorsement on Black students? 7th grade beliefs and later 10th grade self-concept and (2) the relationship between students? stereotype endorsement in 7th grade and their 10th grade self-concept. The results showed that parent beliefs did not predict youths? beliefs. However, boys in 7th grade with a more positive perception of Blacks? verbal abilities had a higher verbal self-concept in 10th grade. In addition, boys with a more positive perception of Whites? verbal abilities had a lower verbal self-concept in 10th grade.
Abstract: Meiotic recombination is the process by which homologous chromosomes exchange genetic material during gamete production by ?crossing over.? This shuffling of parental chromosomes is not only thought to be important for increasing genetic diversity in a population, but also a necessary step in segregating chromosomes appropriately during meiosis. Plant breeders may find it desirable to preserve advantageous gene combinations in their crops through generations and, in this context, manipulation of recombination can have a significant impact in breeding methods. Most eukaryotes, including humans and plants, require at least one crossover (CO) per chromosome to avoid non-disjunction and resulting genetic disorders associated with chromosome mis-segregation. Nonetheless, evidence of crossover-independent meioses have been observed in many organisms including insects such as Drosophila males, mammals, and plants. In all sexually reproducing species studied thus far, including plants, the topoisomerase-like protein SPO11-1 initiates meiotic recombination by catalyzing DNA double-strand breaks (DSBs) to initiate crossing over. Thus in the absence of SPO11-1 recombination does not occur, resulting in a sterile phenotype. My project seeks to find a SPO11-1 mutant that maintains fertility in the absence of recombination through a chemical mutagenesis screen.
Abstract: This research was inspired by the development and rapid growth of Massive Open Online Courses (MOOCs). The project sought to answer the question of whether MOOCs can and are effectively engaging their students in a way that is worth the investment from the Universities and professors who organize the courses. A survey based on the National Survey on Student Engagement (NSSE) was created and distributed to the participants of 8 different MOOCs via discussion forum, including courses in the social sciences, mathematics, computer science, and humanities. Overall, the data indicated courses are challenging the students to a similar level as University courses, but the students do not engage with each other or the professors/teaching assistants to the same extent as traditional University class (even with the efforts taken in MOOCs to provide ?meet-ups?, discussion forums, and virtual office hours) . The findings demonstrate that MOOCs are not yet to the point of replacing higher education, but are more likely to serve as a supplement to the more engaging, traditional University courses. With regards to future directions, findings indicate that efforts can be focused on encouraging honorable student collaboration and more interaction with professors/teaching assistants. Additionally, collecting and comparing data from a survey of traditional online courses with the data from MOOCs would shed light on whether MOOCs.
Abstract: Many reports have been aimed at addressing the degree of automaticity involved in implicit sequence learning. Deroost et al. (2008) showed evidence that during the Serial Reaction Time (SRT) task, participants can implicitly acquire sequence specific knowledge of a complex relevant sequence, while concurrently learning an equally complex irrelevant sequence they are told to ignore. We aimed to investigate the temporal onset of irrelevant sequence learning by extending this paradigm to measure the amount of irrelevant information learned at different time points during the SRT task. In Experiment 1, participants were presented with a complex second order relevant sequence and a simple first order irrelevant sequence and learning was measured after 7 and 12 blocks in separate conditions. In Experiment 2, participants were presented with a complex second order sequence for both relevant and irrelevant stimuli, and learning was measured after 14 and 19 blocks in separate conditions. Results indicated that across all 4 conditions between the two experiments, no significant learning of the irrelevant sequence was found. These results are not in line with the findings of Deroost et al. (2008). We suggest that simultaneous learning of an irrelevant sequence, whether complex or simple, is not as robust as previously suggested.
Abstract: Aphasia is a language disorder resulting from neurological impairment. For those with aphasia, producing fluent speech is difficult, due to problems with word finding, syntax, or speech motor programming (apraxia of speech [AOS]). Several fluency-inducing conditions, including rhythmic stimulation and masking auditory feedback with noise, have led to improved fluency in both adults who stutter and those with aphasia. Rhythm has been indicated as especially beneficial for speakers with nonfluent aphasia. The hypothesis in this study is that speakers with nonfluent aphasia and AOS will have fewer disfluencies under metronomic stimulation than in masking or control conditions, with little change in fluent speakers. Five participants with aphasia produced 20 sentences in each of five conditions, including control, masking, and metronomic stimulation conditions. Results on the fifth speaker and analyses of clinical brain scans are currently underway. Preliminary results indicate that one of four speakers responded with a significant decrease in average disfluency time under rhythmic stimulation (Wilcoxon Z= -3.26, p < .01). No speakers significantly improved during the masking condition. Three of five speakers had fluent aphasia, and the only significantly positive responder had transcortical motor aphasia, a type of nonfluent aphasia. These results suggest that metronomic stimulation may increase fluency in speakers with nonfluent aphasias, and warrant more research.
Undergraduate Co-Authors: Michael Humphries
Abstract: Methods: Patients aged 2-17 years who were admitted to the general pediatrics inpatient service at least 24 hours prior were approached based on random selection and consented. Parent of participant completed survey on home sleep behavior. A video camera was set up, and recording occurred in the patient's hospital room continuously from 20:00 until 08:00. Video was reviewed by assistants, and data related to sleep initiation, duration, interruptions, and associated factors were extracted. Information was extracted on age, race, sex, insurance, diagnoses, and medications; a severity of illness score was assigned to each participant. Analysis included chi square and ttest as appropriate. Results: In enrolled patients (n=51), mean time of sleep initiation was 22:29 (range 21:35-22:42), attempted sleep duration was 524 minutes (range 487-561), and duration of actual sleep was 466 minutes (range 421-511). Subjects were awakened an average of 2.6 (standard deviation=0.7) times per night. The vast majority of awakenings were due either to medical personnel or equipment. Sleep timing was not significantly correlated to age, illness severity, or quality of sleep at home. Later bedtime was associated with less time awake during the night (p=0.009) but less total time asleep (p=0.03). Conclusions: Hospitalized children go to sleep very late at night and have frequent awakenings. Future research should examine if sleep quality can be improved and the impact on patient outcomes.
Abstract: Unhealthy contingencies of self-worth, or areas in an individual's life which predicts rises and falls in self-esteem, such as appearance or academic competence, can lead to unfavorable outcomes, such as body image issues, financial problems, and low self-esteem and well-being. This study demonstrates how a simple writing task focused on a healthier contingency of self-worth such as family support can increase momentary positive emotions. Positive emotions can combat the negative consequences of an unhealthy contingency of self-worth by broadening and building an individual's momentary and personal resources, leading them on an upward spiral of well-being. Our results show that the experimental writing task significantly increased positive emotions in both individuals with healthy and unhealthy contingencies of self-worth, as opposed to individuals who wrote a control essay.
Abstract: Previous studies have shown that prenatal nicotine exposure is linked to an increased risk of developing attentional deficiencies such as ADHD (Horst et al., 2012). The auditory evoked K-Complex is a brain electrophysiological response that is analogous to the attention -response during wakefulness, and it can be indicative of the amount of sensory processing that is occurring (Andreassi, 2007). The K-complex can first be seen in infants around 4 months of age (AASM Manual for Scoring Sleep, 2007) and may represent an antecedent to normal attention maturation in children. In this study, a paired-click paradigm was used to elicit auditory K-Complexes during a nap in 3 groups of children: Control infants, infants exposed to environmental tobacco smoke, and infants exposed to nicotine prenatally. . EEG during Stage 2 sleep was analyzed, and amplitude of the K-complex potential was extracted. Results revealed that the amplitude of the prenatal nicotine exposure group appears to be significantly smaller than the amplitude of the potential in the control and environmental tobacco smoke groups. Findings suggest that the K-Complex can represent an early biomarker for attention deficiencies in high-risk infants with exposure to nicotine.
Undergraduate Co-Authors: Sandy Joyner, Kaitlyn Cartwright
Abstract: News companies, textbook authors, magazines, journal articles and bloggers all want the information that they present to be readily accepted and easily accessible. However, sometimes this information is skewed or blatantly false, and the reader accepts it as true. This research seeks to figure out what about how the medium of communication influences consumer's judgement. There are multiple factors that come into play when a reader makes a judgment on the validity of information, such as source credibility and context. For this study, we wanted to examine whether the quality of writing affects the immediate judgment of validity for news articles, both with real and fictitious content. We found that there was a significant effect of quality of writing and perceived validity, as there was a significant effect on content and perceived validity. However, these two factors were found to not interact. There are limitations to this study, ranging from a small sample size to a lack of generalizability across other age groups and media sources.
Abstract: The purpose of this research project is to collect, record, and report the life story of Kenneth, a man who has severe depression and has been in mental health care in one form or another for most of his 63 years. ?The Life Story of Kenneth? includes his early years growing up in a privileged family and flows into his college years spent at Stanford, where he begins to experience symptoms of depression. His first contact with mental health professionals and his subsequent experiences with mental hospitals and outpatient treatments are accounted in detail. Kenneth?s story then reaches a sort of climax with his time spent without a stable residence in Florida. Kenneth?s historical influence as a founding member of Club Nova, a mental health community center in Carrboro, is also explored. The narrative concludes with where Kenneth thinks he will go from here and some more general reflections on his own life. The primary research material used is three 30-40 minute interviews conducted with Kenneth at Club Nova.
Abstract: Biomedical and social science research largely finds that being married is associated with favorable physical and mental health outcomes. A number of causal mechanisms have been proposed to link marriage to better health, including greater economic resources, stricter adherence to healthy behaviors, higher levels of social integration and social support, more sexual satisfaction, and more purpose and meaning in life among married individuals. Unfortunately, most social science and health research treats the experience of marriage as similar across all population groups, failing to consider the structural and interpersonal factors that influence both marital status and health outcomes. The earliest work in this regard examined how gender shaped the relative mental health benefits of marriage, revealing that marriage improved the mental health of men but diminished that of women, though more recent work finds positive effects for both men and women. Despite the importance of this line of research, very few studies explore whether the marriage-mental health association is similar for Blacks and Whites, and even fewer explore other intersections such as socioeconomic status. We use secondary data from the 2002-2003 Study of Families and Relationships to explore these questions.
Abstract: The present study examines various factors and theories related to the entertainment-education strategy in addition to revisiting Ajzen's (1991) theory of planned behavior in a narrative context. Entertainment education is a health communication strategy that involves educating and persuading individuals regarding health issues by incorporating health information with a story. In addition, when readers identify with a character in a narrative, they are more likely to adopt the character's attitude, beliefs, and goals. The present study employs Batson et al.'s (1997) work on perspective taking. This study utilizes a 2x2 factorial design, as the first manipulation is whether the participant is instructed to remain objective or imagine how the character feels. It is predicted that participants identifying with the character will report higher intentions to exercise. In addition, Courneya et al. (2000) found that social support was a stronger predictor of intentions than subjective norm in the exercise context. The second manipulation is whether a participant reads a narrative about a student who receives social support to exercise, or a student who receives social pressure to exercise. It is predicted that participants reading the social support narrative will report less perceived pressure, higher social support, and higher intentions to exercise. Data are currently being analyzed and will be reported in the final poster, along with implications of results.
Faculty/Postdoc Contributors: Flavio Frohlich
Abstract: Transcranial alternating current stimulation (tACS) is a method of noninvasive brain stimulation in which weak electric currents are applied to the brain. tACS has the potential to be used as a neuropsychiatric treatment. Because of the oscillating waveform of tACS, it may be possible to apply tACS at the same frequency as a patient?s neural activity. It is not yet known which waveforms have the best effects for treatment. To simulate the effects of tACS on ongoing neural oscillations in vitro, we applied optogenetics and weak electric fields to cortical slices and recorded multiunit spiking activity using a multielectrode array. Slices were taken from mice whose Layer V pyramidal cells express channelrhodopsin. We used optogenetic stimulation to entrain the cortical network at 1Hz with pulses of light. Simultaneously, we applied weak electric fields at the same frequency (1Hz) and surrounding frequencies (0.8Hz, 1.2Hz, 2Hz) to mimic tACS. We hypothesized that the effect of tACS would be stronger when the internal and applied oscillations frequencies were matched. We successfully entrained cells in Layer V and surrounding frequencies at 1Hz. Cells did not entrain at surrounding frequencies. These results suggest that 1Hz is a preferred firing rate for Layer V pyramidal cells and that tACS may be used to enhance ongoing network activity. Our findings emphasize the importance of determining individual oscillation frequencies when using brain stimulation as a treatment.
Abstract: People describe positive and negative emotional states with varying degrees of precision, which is known as emotional granularity (Barrett, Gross, Christensen, & Benvenuto, 2001). Recent research from our lab indicates that people are more granular in describing negative emotions as opposed to positive emotions (Rice & Lindquist, 2013) but the reason for this ?valence asymmetry in emotional granularity? remains unclear. The present study thus examined the mechanisms underlying this asymmetry. We predicted that people with more complex conceptual knowledge about positive emotions would also be more granular for positive emotions compared with those with less conceptual complexity. To measure the complexity of participants? concept knowledge, sixty participants (ages 18-22) completed a card sort task (Showers, 1992; Rafaeli-Mor, Gotlib, & Revelle, 1999; Linville, 1985) in which they sorted up to 50 cards each labeled with an emotional attribute into as many emotional categories as they could think of. This task was counterbalanced with a lab-based measure of granularity in which participants viewed an evocative image and rated the extent to which they felt 16 different emotions in 48 trials. We predict that participants who demonstrated greater complexity for positive emotions in the card sort task will show greater granularity for positive emotions in the lab-based measure compared with those participants who exhibited less complexity for positive emotions.
Abstract: Research in recent years has touted the benefits of positive emotions. However, new studies suggest that actively trying to be positive can backfire, leaving a person feeling worse than before. In this study, the efficacy of implicit goals of positivity as an alternate mechanism for mood improvement was investigated. All participants completed a negative mood induction before completing a thought task while being exposed to either positive or neutral environmental cues. During the task, participants were either asked to try to ?improve their mood? or to list whatever thoughts came to their mind. A variety of measures, including number of thoughts, thought automaticity, thought valence, and degree of mood repair were collected across conditions. Despite research to the contrary, most participants experienced greater positivity when given an explicit goal to try to be positive. However, among participants prone to rumination, implicit goals were comparatively more effective in generating positivity. Though the implicit mechanism of environmental cues may not be effective for all people, it seems to be preferable for those with a tendency to dwell on negative thoughts. The possibilities for follow-up research and for practical applications of such findings are discussed.
Abstract: An enhanced sensitivity to fearful faces is evolutionarily advantageous; however, it is unclear at what level of neural processing this bias is realized. There are conflicting results from studies investigating whether the face-specific N170 event-related potential (ERP) component is enhanced for fearful faces. Studies have also shown that task irrelevant fearful faces elicit an ERP index of attentional selection (N2pc), reflecting attentional capture by fearful faces. The present study examined how early perceptual processing related to attentional capture for fearful and neutral faces. Here, we investigated the N170 and N2pc, as well as an ERP index of attentional reorienting (the ?IIN?). Participants performed a modified version of the attentional cueing task, in which a pair of face images preceded the target stimulus. The ERP analyses indicated that the N170 did not differ for fearful and neutral faces, suggesting that fear did not affect this early level of visual processing. Fearful faces did not elicit an N2pc and the targets appearing at the uncued location did not elicit an IIN, suggesting that fearful faces did not capture or hold attention. Overall, these results suggest that neither early visual processing of, nor attentional orienting to faces is necessarily affected by fear.
Undergraduate Co-Authors: Michael H. Parrish
Graduate Student Contributors: Christopher T. Smith
Faculty/Postdoc Contributors: Mary Katherine Kelm
Abstract: Striatal dopamine (DA) has been extensively implicated in reward related processes. We assessed striatal DA variations and delay discounting (DD) behavior in humans by investigating two functional polymorphisms in genes associated with striatal DA signaling. First, the DA transporter (DAT), which is the primary mediator of DA clearance in the striatum; a variable nucleotide repeat polymorphism in the DAT gene is associated with variation in DAT expression, with the 9 repeat variant yielding greater DAT expression relative to longer repeats. Second, a single nucleotide polymorphism in the DA D2 receptor (DRD2) gene linked to variation in striatal DRD2 availability, with the ?T? variant showing greater DRD2 availability relative to ?C? variants. We assessed intertemporal monetary reward choice behavior using a DD task and investigated whether these genetic variations could account for significant inter-individual variance in DD behavior. Among emerging adults (ages 18-25), we observed a significant DAT?DRD2 interaction effect on the sensitivity of intertemporal choice to reward magnitude that followed a quadratic function of genetically predicted tonic striatal DA. Those with genetically predicted intermediate DA showed greater reward sensitivity relative to those with predicted high and low DA phenotypes. This relationship was not observed among adults (ages 26-40). These results suggest that striatal DA signaling modulates reward-related decision-making in emerging adults.
Undergraduate Co-Authors: Melisa Menceloglu, Scott Oppler
Abstract: Alcohol use disorders (AUDs) are highly heritable, with twin studies showing that 40-60 % of AUD risk is genetic. Therefore, family history of alcohol abuse or dependence is an important indicator of risk for the development of an AUD. To date, no neuroimaging studies have examined differences in intrinsic brain connectivity based on AUD family history status in adults. We used intrinsic connectivity MRI analysis to assess the coactivation of predefined brain regions in identified intrinsic networks during the resting state in healthy adults, comparing the neural circuitry of those classified as family history positive (FHP; n=22) or family history negative (FHN; n=36). All participants were screened for psychiatric diagnoses, including any lifetime substance use disorders. The FHP and FHN groups did not differ in terms of age, sex, socioeconomic status, education, IQ, or substance use. Covariation in activity between the right frontoinsular cortex (rFIC), a salience network (SN) node, and frontoparietal nodes of the central executive network (CEN) were compared between FH groups. The SN-CEN connectivity of FHN individuals was significantly greater than that observed in the FHP group (t(56)=2.99, p= .004). These findings predict impaired switching between exogenous and endogenous attention networks in FHP individuals, and provide preliminary evidence that resting state connectivity between frontoparietal and insular regions is a novel biomarker for AUD risk in adults.
Abstract: Obsessive Compulsive Disorder (OCD) is an anxiety disorder characterized by unpleasant, intrusive thoughts or images, obsessions, and ritualized actions or compulsions, which aim to decrease the anxiety caused by the obsessions. This study examined partners? behaviors in response to patients? OCD prior to participating in a couple-based treatment intervention for OCD. The extent to which partner behaviors in response to OCD beyond general relationship functioning affects treatment outcome is of interest. High levels of accommodation at pre were hypothesized to correlate with less improvement. 16 couples with one partner meeting diagnostic criteria for OCD enrolled in the study. An observational coding system was adapted to measure partner behaviors during videotaped interactions, including Promotion of Change, Acceptance/Validation, and Accommodation. Higher levels of partner Accommodation at pre were indicative of poor treatment outcomes, and an interaction effect between high levels of Promotion of Change and low levels of Acceptance/Validation were associated with better outcomes. Together, the main and interaction effects explained up to 44% of the variance in OCD treatment outcome and replicate prior findings that in response to psychopathology, partners who demonstrate ?tough love? create the best environment for improvement. Limitations are discussed. Results emphasize the importance of the interpersonal context of OCD and possible directions for future clinical work.
Abstract: Human embryonic stem (hES) cells are unique?they are the precursors of life but are also primed to undergo rapid cell death by apoptosis. Recent findings show that hES cells maintain an important pro-apoptotic protein called BAX at the Golgi apparatus in a constitutively active state that promotes their ability to undergo rapid cell death. The present study explored two groups of proteins in the BCL-2 family known to interact with BAX in other cell types in order to understand whether these proteins function in hES cells to maintain BAX in a constitutively active state and keep active BAX from triggering cell death in the absence of appropriate stimuli. The proteins of inquiry include pro-apoptotic BH3-only proteins BID, BIM, and PUMA and anti-apoptotic BCL-2 family proteins BCL-2, BCL-Xl, and MCL-1. Immunofluorescence and immunoprecipitation techniques were used to visually and qualitatively confirm protein interactions with BAX. The results suggest that pro-apoptotic proteins BIM and PUMA colocalize with active BAX at the Golgi apparatus in hES cells, indicating an interaction with active BAX. They are also localized to some extent at the mitochondria. Furthermore, some of the total cellular BIM and PUMA protein is binding directly to active BAX, indicating a direct interaction. Neither BID nor the anti-apoptotic proteins were found to localize to the Golgi apparatus or bind to active BAX. Overall, these findings help to illuminate more about the basic biology of hES cells.
Undergraduate Co-Authors: Ashley Creese
Faculty/Postdoc Contributors: Alana Campbell
Abstract: Estimates show that up to half of recent combat veterans with traumatic brain injury (TBI) also meet criteria for posttraumatic stress disorder (PTSD). Both TBI and PTSD are characterized by deficits in executive functions, such as poor attention, cognitive control, and inhibition. TBI and PTSD also share symptoms related to affective processing, particularly affective control, hyperarousal, irritability, anger, and anxiety. The goal of the current project is to examine electrophysiological correlates of executive and affective functions in PTSD/TBI patients and compare these correlates to clinical symptoms. The P3 event-related potential is an electrophysiological component elicited in oddball tasks and related to executive functions. Electroencephalogram (EEG) was recorded while Patients completed an oddball task in which they responded to an infrequent target amid frequent standard stimuli. In one task version we introduced emotional stimuli to distract from target detection. We examined the P3 response to the target stimuli in both tasks to assess their relationship to severity of clinical symptoms in PTSD and TBI. The results suggest that affective information diminishes executive responses. These results provide information regarding the neural underpinnings of executive functions, affective processing, and PTSD/TBI.
Abstract: While distressing, intrusive thoughts are experienced by 84 percent of the population, individuals with Obsessive Compulsive Disorder experience greater distress and feel a greater sense of the importance and need to control their thoughts. Thus, it is worthwhile to investigate what differentiates clinical symptoms from everyday thoughts at the cognitive level. This study improves on previous research on the relationship between dysfunctional beliefs, maladaptive thought control strategies, and OCD symptoms by employing the Dimensional Obsessive Compulsive Scale (DOCS). We also employed data from the Thought Control Questionnaire (TCQ) and Obsessive Beliefs Questionnaire(OBQ) to measure coping strategies and cognitions, respectively. We used a sample of 103 participants diagnosed with OCD and receiving treatment at Rogers Memorial Hospital in Wisconsin. First, we examined simple Pearson correlations between the TCQ subscales, OBQ subscales, and DOCS subscales. Also, we conducted partial Pearson correlations between the TCQ subscales and OBQ subscales controlling for trait anxiety (STAI T) and depression (BDI II). When partialing out for these two factors, there was a significant relationship between punishment and unwanted thoughts as well as punishment and the importance of and need to control thoughts. This suggests these relationships are specific to OCD and treatment should be tailored to addressing this thought control strategy.
Abstract: Life as a college undergraduate comes with numerous social, psychological, academic, and physical stressors, which can often trigger disordered eating behaviors. Approximately 11-20% of college women in America are within the clinical range for disordered eating and endorsement of extreme weight control behaviors. Disordered eating behaviors can quickly spiral into eating disorders, which are severe mental illnesses with serious consequences that require psychological and medical treatment. Early intervention is most ideal for full recovery. The Internet has proven to be an effective tool in reaching out to young adults regarding mental health interventions. Today?s college students spend much of their time on social media networks such as Facebook. The overarching goal of the present study was to survey college-aged women on their Facebook engagement and examine associations between self-reported Facebook activity and eating psychopathology. We identified individuals who may be in need of enhanced care by examining whether Facebook activity was associated with disordered eating behaviors. Ultimately, social media outlets could be used as a supplemental diagnostic tool, which could lay the groundwork for a future digital safety net to ease students into the transition away from reliance on parental monitoring of nutrition.
Abstract: Bullying and harassment within the K-12 school setting, based on research studies continues to be a problem with great consequences for the victims such as depression, suicidal thoughts, lower grade point averages, high truancy and high drop-out rates. There has been research exploring the bullying and harassment of students based on social identities such as race/ethnicity, ability status, gender/sex assigned at birth, gender identity &/or gender expression, and sexual orientation. While there has been some examination of the frequency of harassment and the impact of bullying and harassment on disparate aspects of identity in isolation, the reality is that people who hold multiple marginalized identities often experience harassment based on multiple identities. Far less research exists on the academic impacts of harassment based upon multiple intersecting identities simultaneously. This study attempts to address this gap in the literature by assessing the frequency and severity of harassment based on race/ethnicity, ability status, gender/sex assigned at birth, gender identity &/or gender expression, and sexual orientation and the role it plays on aspirations for pursuing higher education. This voluntary,non-compensated online survey allows students to provide input on changes to schools, which will fosters an inclusive and safe environment that promotes academic success.
Abstract: This research project is a study of the impact of the Katosi Women Development Trust (KWDT) on the rural communities in the Mukono District of Uganda using both the goal attainment approach and the systems resource approach as measures of NGO service evaluation. More specifically, this project aims to: outline the goals of KWDT as defined by the organization and assess to what level the goals have been attained, use the systems resource approach to analyze sources of funding and how those resources are used, test the effectiveness of humanitarian assistance by analyzing both the outcomes of KWDT projects and the means with which they achieve results. It is estimated that 24.5% of Ugandans currently live in poverty, thus KWDT?s activities continue to have particular relevance, with the group serving as an example of a typical African non-profit organization (?2012 Statistical Abstract?, 2012). Obtaining knowledge about KWDT?s effectiveness can help shed light on the impact of development organizations in general and whether humanitarian assistance achieves desired goals. My finding will be a significant contribution to the literature on ?aid? as there are divergent ideas about the effectiveness of aid by researchers such as Sachs and Moyo (2009), and hence there is continuing research to understand whether aid works.