Dissertations
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Item Embargo Using A Sexual & Gender Minority Health Disparities Framework To Examine Multi-level Influences On Bisexual College Women’s Sexual Health Communication About HIV(East Carolina University, July 2024) Muscari, EmmaPrior studies have consistently revealed that bisexual+ women are at an increased risk for numerous mental and sexual health disparities compared to individuals with differing sexual orientations, in part due to bierasure and binegativity—yet less is known about bisexual+ women’s approaches to obtaining information about partner sexual health and HIV status. My dissertation employed a mixed-methods approach to investigate sexual health communication strategies (i.e., requesting partner sexual health history) as a means of HIV prevention, and the multi-level psychosocial factors that underlie sexual health communication related to HIV. Specifically, I assessed the individual, interpersonal, community, and societal factors—informed by the Sexual & Gender Minority (SGM) Health Disparities Research Framework and the Theory of Planned Behavior (TPB)—that guide sexual health communication in bisexual+ college women. A total of 258 bisexual+ college women completed an online survey that assessed for multi-level factors that affect HIV-related sexual health disparities and HIV prevention behaviors. Across levels of influence in the SGM ecological framework, community level influence in the form of LGBTQ community connectedness predicted bisexual women's individual level experience of sexual identity outness (i.e., more LGBTQ community connectedness predicted more sexual identity outness). Societal level influence in the form of bierasure predicted medical mistrust on the interpersonal level (i.e., less bierasure predicted less medical mistrust). When examining ecological influences on variables associated with the TPB, more LGBTQ community connectedness and less internalized heterosexism predicted more favorable attitudes around having a shared sexual conversation. More LGBTQ community connectedness also predicted more perceived social pressure around having a shared sexual conversation. Examining TPB variables more focally, the TPB intermediate variable of intention was not only influenced by upstream TPB variables (more attitudes, norms, and self-efficacy predicted greater intention) but also predictive of TPB outcome variables of sexual safety strategies and request for partner sexual health history. A qualitative analysis of HIV prevention behavior (request for partner sexual health history) yielded three themes across participants who reported requesting history: 1) Style, 2) Content, and 3) Timing, and one theme across participants who did not request history: 1) Barriers. The Barrier theme had seven subthemes: Discomfort, Unaware, Managing Partner Reactions, Perceived Minimal Risk, Partner Initiated, Social Norms, and Perceived Lack of Relevance. Qualitative responses provided context for upstream TPB variables and elucidated specific attitudes, norms, and efficacy factors that are involved in shared sexual health conversations. Future research should continue to take a multi-level approach in capturing the numerous factors that influence HIV-related sexual health outcomes for bisexual+ women. HIV prevention programs should consider how fostering positive attitudes, favorable social norms, and self-efficacy influences request for partner sexual health history.Item Embargo Use of Modular Therapy to Treat Anxiety for School Age Students with Autism(East Carolina University, July 2024) Glenn, Melissa RegineAutism spectrum disorder (ASD) is a neurological disorder characterized by challenges with social communication, interpersonal skills, sensory stimulation, and restricted and repetitive behaviors. Because of these challenges, the social demands of school can produce anxiety in some children with ASD. Although practitioners use several evidence-based interventions to treat autism, there are few evidence-based treatments to address the anxiety symptoms commonly associated with individuals with ASD. This study aims to determine the extent to which perceived anxiety levels decrease for school-age children with autism who also present with anxiety-related concerns, the extent to which children with ASD rate the usefulness of the intervention, and measure parent and teacher satisfaction with the intervention and perceived behavioral outcomes. The school psychology researcher will use a modified version of the Modular Approach to Therapy for Children with Anxiety, Depression, Trauma, and Conduct Disorders (MATCH-ADTC) to include more visuals, schedules, and social stories. In addition, the researcher intends to determine the effectiveness of the intervention by collecting data on the students’ engagement (determined by the practitioner) and feedback on the students’ experience (determined by the student).Item Embargo Feasibility and Acceptability of a Behavioral Intervention Program Among Patients with Atrial Fibrillation to Promote Engagement in Physical Activity(East Carolina University, July 2024) Anthony, Scarlett LeighContemporary AF management includes rate control, rhythm control, anticoagulation, and lifestyle management. Lifestyle management remains aspirational for most clinical settings around the world. Achieving regular physical activity (PA) is daunting for patients and programs such as cardiac rehabilitation are often not available, or not covered as in the USA, leaving few treatment options for patients. This study employed a behavioral PA intervention focused on psychoeducation, aerobic exercise, and problem solving to examine the feasibility and acceptability of a brief PA intervention among patients with AF in a rural-serving clinic. 128 patients were approached in clinic and a total of 24 participated in the study. Accelerometer data revealed an average of 255 minutes of moderate and vigorous PA per week (36.4 min/day) at baseline and 298 minutes of moderate and vigorous PA per week (42.6 min/day) at the end of program. Accelerometer data showed an average of 18.24 hours per day of sedentary time at baseline compared to 17.18 hours per day at the end of the program. Despite increases in PA, overall symptom burden and quality of life scores remained consistent. The average rating of patient satisfaction of the program was 21.8 out of 25 indicating high satisfaction. High attendance rates and patient satisfaction ratings provide preliminary evidence of the feasibility and acceptability of a PA behavioral intervention for patients with AF. Findings suggest that programs have the potential to improve PA levels in rural-serving clinics.Item Embargo MICROBES AND AIRPLANES: INVESTIGATING MICROBIOLOGICALLY-INFLUENCED CORROSION OF SUBMERGED WORLD WAR II AIRCRAFT WRECK SITES(East Carolina University, July 2024) Bush, Dominic W.There is perhaps no better symbol of the destruction, technological advancement, and geographical scale of World War II than aircraft. Today, thousands of these wartime vestiges are located beneath the ocean’s surface, serving as a highly sought after form of material culture. While archaeologists tend to opt for in situ preservation strategies, there are those who have advocated for a different ‘preferred’ option, instead promoting recovery. Proponents of the latter perspective have levied charges of inaction against archaeologists, citing unchecked degradation as the impetus for salvaging submerged aircraft wreck sites. To counter these claims, and better understand the degradative forces that place these sites at risk, the totality of environmental factors needs to be comprehensively assessed. This includes a site’s microbiome, as previous research has indicated that colonizing microorganisms have the potential to detrimentally impact steel shipwreck sites and other forms of underwater cultural heritage. However, aluminum aircraft of World War II have yet to be the focus of similar investigations, leaving a void in the field’s understanding regarding in situ preservation threats. Thus, this dissertation is the first attempt to extend this line of research to submerged aircraft wreck sites, using four sites in Hawaiʻi. The first step involves characterizing the microbes present, which necessitated sound collection protocols for obtaining microbial samples. The methodology developed for this project was designed to be practical, affordable, and amenable to a variety of uses. The successful collection of biofilm, the main form of biofouling on submerged aircraft wreck sites, enabled DNA sequencing of the material from these samples. The sequencing results allowed for an interpretation of the microbial assemblages associated with corroded and non-corroded wreck surfaces. While no significant taxonomic differences were identified between corroded and non-corroded samples, the study succeeded in defining the microbial communities of submerged aircraft wreck site biofilm, which appeared compositionally-distinct from those of the surrounding seawater and sediment. In addition to identifying key constituents, the data indicated that environmental factors, including the background microbiome and sedimentary interactions, play a prominent role in shaping submerged aircraft wreck site biofilms. Ultimately, evidence of microbiologically-influenced corrosion of submerged aircraft wreck sites remains inconclusive, although significant strides were made in understanding the microbial communities associated with these sites. For archaeological management, the study provides a sound methodology for future collections, baseline data, and the identification of necessary approaches and additional lines of evidence. There is an inherent value in being the first to attempt to see what works, thus serving as a launching point for future, more sophisticated forms of analyses that strive towards developing definitive statements on the relevancy of microbiologically-influenced corrosion to the in situ preservation of submerged aircraft wreck sites.Item Embargo Evaluation of a Measure of Everyday Function in Older Adults; Use of a Rural-Serving, Outpatient Neurology Clinic Sample(East Carolina University, July 2024) Sorrell, Anne ElizabethBackground: Understanding a patient’s ability to complete instrumental activities of daily living (IADLs) provides valuable insight into the cognitive and functional decline associated with diseases of aging, such as neurocognitive disorders. Early and accurate evaluation of IADLs permits healthcare professionals to conceptualize level of impairment, track disease progression, and tailor interventions to support patients in preserving quality of life and, in some cases, slow decline for as long as possible. Revised in 2021, the Everyday Cognition scale (ECog-II; Farias et al., 2021) is a measure of IADLs, unique for its evaluation of everyday functioning relative to specific cognitive domains often examined in comprehensive neuropsychological evaluations and for its ability to be used both by patients and their informants. Purpose: The purpose of the present study was to evaluate the clinical utility of the ECog-II Patient- and Informant-Reports in an outpatient neurology clinic that primarily serves rural-living patients in the southeastern United States presenting with comorbid medical and mental health conditions. Methods: A total of 106 patients from an outpatient neurology clinic in Eastern North Carolina who were internally referred for neuropsychological testing were included in the present study. The sample included 52 patients with mild cognitive impairment (MCI), 48 patients with dementia, and six patients without any objective cognitive impairment. Patient reports and informant reports from the ECog-II were administered, which include a total Global factor score and six domain-specific factor scores: Everyday Language, Everyday Memory, Everyday Visual-spatial/perceptual abilities, Executive Functioning (EF): Everyday Planning, EF: Everyday Organization, and EF: Everyday Divided Attention. All patients also completed a neuropsychological test battery as standard of care, and age-normed standard scores were calculated for each measure. The study sought to examine differences between respondent types, evaluate construct and predictive validity, and develop cut-off scores for the global factor. Results: Evidence of convergent validity between ECog-II responses and gold standard neuropsychological measures of similar constructs was demonstrated. Observed trends are highlighted in the manuscript. Predictive validity between diagnostic severity, but not etiology, was established using informant reports. Global cutoff scores for ECog-II informant report data with adequate sensitivity and specificity were established. Data from patient self-reports were less significant overall, and predictive validity was no better than chance. As such, global cutoff scores were unable to be established based on patient-report data. Overall, results from the current study suggest that informant reports of patient IADLs and everyday cognitive functioning map on better to objective neuropsychological measures compared to patient reports. Discussion: Results suggest that when evaluating neurocognitive impairment in rural-living older adults with varying comorbid medical health conditions, objective neuropsychological assessment remains the gold standard as subjective reports are not as predictive of actual cognitive functioning. Patient reports of IADL functioning are encouraged for enhanced understanding of patient awareness and insight. Collateral reports are encouraged for use in clinical decision making to supplement, but not replace, neuropsychological test data. Future studies are encouraged to collect a larger, heterogeneous diagnostic sample to further understand cognitive and functional impairment in a predominantly rural-living, southeastern patient population.Item Embargo The Effect of Exercise Mode During Pregnancy on Maternal, Placental, and Cord Inflammatory Markers(East Carolina University, July 2024) Wisseman, Bree LynnABSTRACT Excessive inflammation during pregnancy is associated with adverse pregnancy outcomes. Specifically, increased pro-inflammatory tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), interleukin 1 beta (IL-1ß), interleukin-8 (IL-8), and c-reactive protein (CRP) have been associated with gestational diabetes, preeclampsia, intrauterine growth restriction, and preterm birth. Similarly, pathologies of the maternal-fetal interface, such as recurrent spontaneous abortion, are associated with high pro-inflammatory biomarkers. This also increases fetal exposure to high inflammation in utero, contributing to the increased risk of cardiometabolic and mental conditions later in life. In non-gravid adults, exercise is an effective method for reducing pro-inflammatory and increasing anti-inflammatory biomarkers, differing with exercise mode. Currently, no research has directly compared the effect of exercise modes during pregnancy on maternal, placental, and fetal inflammatory biomarkers. The purpose of this dissertation was to determine the effect of maternal aerobic, resistance, or combination (aerobic + resistance) exercise during pregnancy on maternal, placental, and cord inflammation. Samples from healthy pregnant women with singleton pregnancies that participated in a randomized control trial exercise intervention were obtained. The exercise intervention consisted of 150-minutes of moderate-intensity aerobic, resistance, or combination exercise per week from <16-wks gestation until delivery. First, we investigated the effect of exercise mode on inflammation in maternal plasma at enrollment (<16-wks) and 36-wks gestation. Second, we examined the concentration of inflammatory biomarkers in placental tissue. Third, cord blood was analyzed for inflammatory biomarkers. All studies utilized Luminex xMAP technology to quantify biomarker concentration. The second and third studies also identified protein and pathway differences with exercise using a label-free proteomics. Maternal, placental, and cord blood inflammatory biomarkers were similar between groups. However, these data revealed that other exercise metrics predicted inflammatory biomarker concentration. Specifically, increased weekly exercise duration predicted lower IL-6 and IL-8 and increased weekly exercise frequency predicted higher TNF-α in late pregnancy maternal plasma. Increased weekly exercise intensity predicted lower placental fibrinogen. Lastly, total exercise volume, exercise mode, and pre-pregnancy BMI predicted cord blood IL-6 and exercise mode and pre-pregnancy BMI predicted cord blood cortisol. Label-free proteomics revealed significantly different proteome landscapes in aerobic, resistance, and combination exercisers placental tissue and cord blood compared to controls. We identified multiple downregulated proteins in placentas of exercisers that related to inflammation and immunity. Similarly, there was a downregulation in cord blood pathways that related to innate and adaptive immunity, possibly indicating reduced downstream inflammatory biomarkers. Altogether the studies within this dissertation did not support our central hypothesis that exercise mode would differentially alter inflammatory biomarkers during pregnancy. However, our studies highlight the importance of monitoring all exercise metrics (e.g., frequency, intensity, time, type), as each related to changes in maternal, placental, and fetal inflammation. We were also able to identify other inflammatory proteins and pathways in placental tissue and cord blood, providing targets for future projects. Collectively, the studies within this dissertation support the safety of exercise during pregnancy, further emphasizing the possible benefits, regardless of exercise mode. The projects in this dissertation extend the knowledge on how antenatal exercise impacts inflammation during pregnancy, thus impacting maternal and infant health.Item Embargo Complementary Square Wave Voltammetry and LC-MS/MS Analysis to Elucidate Induced Damaged and Mutated Mitochondrial and Nuclear DNA from Biological Organisms(East Carolina University, July 2024) Lafave, Elizabeth RoseElectrochemical methods coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) were developed and applied to rapidly analyze DNA structure, sequence variations, and damage in biological systems. Square wave voltammetry (SWV) at pyrolytic graphite electrodes with immobilized DNA allowed detection of guanine oxidation peaks catalyzed by Ru(bpy)32+. Peak current differences compared to wild-type (WT) or unaltered samples indicated DNA structural changes, which were validated through LC-MS/MS base compositional analysis of hydrolyzed DNA samples. Breast cancer 1, early onset (BRCA1) gene codes for the DNA repair enzyme Brca1 and impacts skeletal muscle function when mutated. To study Brca1's role, inducible skeletal muscle-specific BRCA1 knockout (KO) mice were generated. Initial phenotypic assays indicated increased mitochondrial DNA (mtDNA) mutation frequency in KO vs wildtype (WT). Applying the electrochemical approach, mtDNA from Brca1 KO skeletal muscle displayed statistically significantly decreased oxidative currents vs. WT, consistent with guanine depletion due to mtDNA mutations. Conversely, nuclear DNA (nDNA) showed increased currents in KO samples, suggesting accumulation of oxidatively damaged guanine (p < 0.05). Subsequent LC-MS/MS composition analysis validated these hypotheses, allowing us to quantify suspected guanine variations, as well as detect the remaining DNA bases (adenine, thymine and cytosine) and commonly damaged bases (8-oxoguanine, fapyadenine). The electrochemical – LC-MS/MS approach was further utilized to study the role of overexpressed Brca1 in various muscle locations, detect and identify DNA variations in Ni2+- treated Caenorhabditis elegans, study genetic changes in additional mouse models (i.e. Col5a1 for Ehlers-Danlos, MDX for muscular-dystrophy), and monitor DNA change in Hydrogenophaga taeniospiralis, a benzene-exposed bacteria. Combining electrochemical and mass spectrometry techniques allowed for validation of DNA structural changes observed in phenotypic studies, while also providing a versatile approach to comprehensively investigate a wide range of biological questions, as well as chemical analyses of historical artifacts. Finally, further utilization of analytical methodology, predominantly LC-MS/MS, for historical medicines provided insight into often unlisted ingredients and potential contaminants, addressing lingering historical biases towards alternative treatments during the 19th century.Item Embargo Effect of Metformin Treatment in Gestational Diabetes Mellitus on Infant Mesenchymal Stem Cell Metabolism(East Carolina University, July 2024) Biagioni, Ericka M.Offspring born to women with gestational diabetes mellitus (GDM) experience long- and short-term health consequences that may be partially mitigated through effective and timely treatment of maternal hyperglycemia. Metformin is an effective anti-diabetic agent that is increasingly prescribed to pregnant women for the treatment of GDM. However, metformin readily crosses the placenta into fetal circulation and concerns regarding the potential impact on fetal development have not been adequately addressed. While investigations conducted in animal models have produced controversial findings, randomized controlled trials in humans have reported altered postnatal growth during infancy and childhood among offspring exposed to metformin in utero. Furthermore, the underlying causal mechanisms by which metformin exerts lasting effects on offspring remain unclear. Nevertheless, the use of human umbilical cord derived mesenchymal stem cells (MCSs) has recently gained recognition as a robust model for studying infant cellular outcomes, and current evidence demonstrates that outcome measures from infant MSCs are tightly correlated with longitudinal measures of infant clinical outcomes, such as adiposity measured from birth to 4-6 years of life; thus, infant MSCs present a unique opportunity to study infant cellular outcomes. To investigate the impact of in utero metformin on infant MSC energy metabolism, we collected infant MSCs from exclusively diet controlled (A1DM-MSCs) or metformin treated (Met-MSCs) GDM pregnancies. In aim one of this dissertation, we investigated the impact of in utero metformin exposure on infant MSC substrate oxidation and insulin action under basal conditions and in response to excess fatty acids using radiolabeled glucose, oleate, and palmitate tracers. Measurements of MSC lipid accumulation and mitochondrial content markers were also conducted, in addition to metformin concentrations in cord blood plasma samples. Met-MSCs displayed lower rates of oleate oxidation under basal conditions, compared to A1DM-MSC, despite no differences in mitochondrial content or lipid availability. Additionally, differences in oleate oxidation were no longer apparent under conditions of excess fatty acids. We also reported a large variability among cord blood plasma metformin concentrations, which did not associate with measures of maternal metformin dosing. In aim two of this dissertation, we examined the impact of in utero metformin exposure on infant MSC mitochondrial capacity and control of respiratory flux across physiologic energy demands in the presence of substrates specific to respiratory complex I (CI), CII, and fatty acid oxidation using cellular respirometry. We also investigated the relationship between metformin exposure measures and MSC mitochondrial outcomes. Met-MSCs exhibited lower mitochondrial maximal capacity and diminished CII-linked respiration and respiratory conductance compared to A1DM-MSCs. We also reported relationships between length of in utero metformin exposure and mitochondrial protein expression of CII and citrate synthase. Collectively, these data demonstrate that infant MSCs adaptively respond to in utero metformin exposure, as evident by the lasting effects observed in infant MSCs in the absence of metformin. These findings are clinically relevant and will help inform clinicians of the potential effects of prescribing metformin to pregnant women diagnosed with GDM on the developing fetus, thus increasing the level of care provided.Item Embargo An exploration of the effects of productivity, predators, and nutrient enrichment on metacommunity structure(East Carolina University, July 2024) Leavitt, Jasper SiemannTo understand patterns in biodiversity, we first need to understand how it is organized across the landscape. Diversity can be measured in a single patch of habitat as the number of species and number of individuals per species, but patches do not exist in isolation. By organizing the landscape into a collection of patches of habitat, we can define the broader diversity of the metacommunity. By identifying changes to diversity in a single patch (local diversity or alpha diversity) and determining the heterogeneity of diversity among patches (turnover or beta diversity), we can begin to can predict changes in diversity across the landscape (regional diversity or gamma diversity). The aim of this dissertation was to investigate how abiotic and biotic factors influence beta diversity across multiple spatiotemporal scales using a variety of diversity metrics. Using a long-term dataset, I was able to determine that the relationship between primary productivity and species turnover varied across years in part due to annual fluctuations in environmental conditions. To answer questions about how changes to habitat suitability affected community assembly, I conducted experiments in artificial ponds to test the effects of predation and nitrogen enrichment on macroinvertebrates. Fish presence in ponds had a stronger effect on prey diversity than newt or Anax presence, reducing overall richness while increasing abundance of lower-trophic level taxa with some differences across spatial scales. Moderate nitrogen enrichment in ponds increased taxonomic heterogeneity and the heterogeneity of traits present among patches in the metacommunity, but overall, there were signs of functional redundancy across the metacommunity. Together, these results show the breadth of applications of metacommunity ecology for predicting the effects of multiple environmental factors on biodiversity across spatial and temporal scales.Item Embargo Whole-Body Metabolic Flexibility is Discordant with Skeletal Muscle Metabolism(East Carolina University, July 2024) Krassovskaia, PolinaMetabolic disease continues to be a worldwide problem that affects all ages, sexes, and socioeconomic statuses. The development of metabolic disease is multifactorial with both genetic and environmental components. Because of this, interest has grown in the early identification of individuals susceptible towards the development of metabolic disease. Metabolic flexibility has gained standing as a metric of metabolic health and can be defined as the ability to appropriately adapt substrate utilization in response to substrate availability. Skeletal muscle (SkM) is a regulator of metabolic flexibility as it is the primary tissue responsible for post-prandial substrate handling, and metabolic inflexibility can be seen in the SkM of individuals with metabolic disease. As Western style diets are proportionally heavy in fats and implicated in the development of obesity, metabolic flexibility with lipids is of particular interest. High-fat diets (HFDs) are a common and successful approach for distinguishing differences in metabolic flexibility with lipids across populations. Some evidence exists for metabolic inflexibility in healthy, lean individuals, which suggests metabolic flexibility may be an innate component of SkM. Studies of individuals with overweight allow insight into the intrinsic characteristics of SkM that promote the development of metabolic disease, yet this population remains largely understudied. The current study aimed to assess metabolic flexibility in a population of healthy individuals with overweight with a 3-day HFD. In chapter 2, we show that the participants studied are sedentary, have overweight, and do not display evidence of dysglycemia or dyslipidemia. Participants did not differ in dietary habits before or during the diet. Metabolic flexibility was calculated as the change in SkM homogenate palmitate oxidation with the high-fat diet. Metabolically flexible individuals show almost a two-fold increase in palmitate oxidation with the diet, while inflexible individuals decrease oxidation by about one-third of pre-diet rates, and this occurs without any changes to pyruvate oxidation. Metabolic flexibility was not associated with skeletal muscle fiber type. The change in the respiratory quotient during a hyperinsulinemic-euglycemic clamp is a classical approach towards assessing metabolic flexibility; we found that this was not associated with metabolic flexibility when measured as the change in palmitate oxidation in homogenates with the diet. Additionally, flexible and inflexible participants did not differ in mitochondrial function. Taken together, this indicates that metabolic flexibility is an innate component of SkM and can be seen prior to any clinical evidence of metabolic disruption, and metabolic flexibility is not associated with either muscle fiber type or mitochondrial function. In chapter 3, we utilized primary human skeletal muscle stem cells (HSkMCs) of the same cohort of participants studied in chapter 2. We show that a 3-day HFD does not result in changes in HSkMC metabolism measured by substrate oxidation, glycogen synthesis, and protein content of mitochondrial markers and PGC1a. Cells were additionally incubated with a lipid cocktail for 24 hours, which has been shown to help distinguish differences in metabolic flexibility in HSkMCs. Even with lipid treatment, no effect of the HFD was seen. Although participants were stratified based off the change in palmitate oxidation seen in SkM homogenates, a main finding was that HSkMCs of flexible individuals show enhanced glucose metabolism seen as higher glucose oxidation efficiency. Interestingly, measures of HSkMC lipid metabolism did not associate with similar measures of homogenate lipid metabolism. Together, these data provide novel findings demonstrating that metabolic inflexibility is present in SkM prior to detection at the whole-body level and occurs without any clinical markers of metabolic disturbance.Item Embargo Identifying current and future fish spawning habitat for fisheries management applications via oceanographic models: Case studies for Nassau Grouper (Epinephelus striatus) and Southern Flounder (Paralichthys lethostigma)(East Carolina University, July 2024) Bartlett, Brian S.For many fish species, spawning habitat is a smaller, but critical subset of overall habitat range. Spawning habitat contributes to both recruit abundance and metapopulation connectivity. As a result of these contributions, an understanding of spawning habitat dynamics is critical for managers to effectively manage a species. Further, due to climate change, many fish species’ spawning habitats are likely to change, either in location or timing. The goal of this research was to utilize oceanographic models, coupled with biological models, to (1) assess the effectiveness of future spatiotemporal management on Nassau grouper under varying climate change, (2) investigate seasonal sea surface temperature changes as a biological cue for spawning under global warming, and (3) identify potential spawning grounds of southern flounder captured near Beaufort Inlet, NC. Results show that spawning habitat suitability declined by as much as 70% throughout the region by the end of the century compared to a historical baseline. Despite these declines, it was also shown that regions within marine protected areas had less severe declines than regions outside protected areas, suggesting that habitat refugia will be important for protecting Nassau grouper spawning habitat. It was also shown that the greater Caribbean Sea will experience uneven rates of temperature changes under global warming, with differences varying regionally and seasonally. Summer and winter experience the greatest changes, with species experiencing the highest impact from anthropogenic forces during the seasons they spawn. Finally, it was shown that the overall distribution of possible spawning sites of southern flounder varied from year to year, however the center of gravity was consistently in southern Onslow Bay, NC, across months and years. It was also shown that much spawning appeared to occur local to the capture site, but individual, long-distance dispersal events may help maintain genetic homogeneity throughout the stock. This research shows that utilizing climate models with biological modeling can provide important insight into fish spawning habitat currently, and under climate change. This work will be relevant to help protect species from overfishing and climate impacts via more knowledge-based management.Item Embargo Molecular insights into the regulation of complement protease C1s by the multi-specific SERPIN C1 esterase inhibitor(East Carolina University, July 2024) Garrigues, Ryan J.Functioning as a sentinel of the innate immune response, the complement system is an evolutionarily ancient proteolytic cascade that is involved in the recognition, opsonization, and lysis of foreign pathogens and apoptotic cells. Initiation of this system is paramount to the potency of the immune response but must be carefully controlled by negative regulators to mitigate aberrant activation. One such regulator, known as C1 esterase inhibitor (C1-INH), is the only canonical complement regulator that directly inhibits the initiating proteases of the classical pathway of complement C1r and C1s. C1-INH is part of a superfamily of serine protease inhibitors (SERPIN), which covalently react with target proteases through a substrate-like reactive center loop (RCL). In addition to its regulatory role in complement, C1-INH is multi-specific targeting a dozen proteases of the coagulation, contact, and fibrinolytic systems. Dysregulation of C1-INH is most apparent in congenital loss-of-function mutations of its encoding gene SERPING1 which causes a chronic debilitating disease known as hereditary angioedema (HAE). However, the molecular basis for C1-INH recognition of any of its cognate proteases including C1s has yet to be elucidated. Towards this end we aimed to characterize the SERPIN domain of C1-INH using a bacterial expression system and determine the molecular basis for C1s interactions. Utilizing structure-guided site-directed mutagenesis coupled to a novel surface plasmon based C1s binding assay we show that C1-INH relies on an extensive binding surface outside of the RCL for full affinity. The implications of this structure to the fields of SERPIN biology are discussed.Item Embargo COVID-19 AND COLLECTIVE TRAUMA: A QUALITATIVE DESCRIPTIVE STUDY EXPLORING THE EXPERIENCE OF A PANDEMIC FROM A NURSING PERSPECTIVE(East Carolina University, July 2024) Evans, Kara HedvigThe COVID-19 pandemic can be described as a collective trauma – a shared traumatic experience that will continue to impact physical, mental and psychosocial health for years to come. For nurses, the impact was compounded by existing workplace concerns including burnout, traumatic stress, and unhealthy work environments that also contribute to poor patient outcomes. While there is broad recognition of the importance of nurse well-being to public health, prior research emphasized individual-level causes and interventions that have had limited impact. Therefore, the purpose of this study was to explore the experience of nurses in the aftermath of the COVID-19 pandemic to develop knowledge of the structural and social factors that influence nurse well-being. This qualitative descriptive study employed collective trauma as a sensitizing framework and was conducted in two phases. Phase I results indicated that two years into the pandemic, disrupted connections between nurses and their peers, patients, and the community challenged participants’ sense of meaning and purpose. Phase II data, collected two years later, extended these findings by illustrating how the pandemic’s long-term impact on collective identity and social capital intersects with systemic deficiencies in the work environment to influence nurse well-being.Item Embargo The Effects of Self-Disclosure on Attitudes Toward Seeking Professional Psychological Help Among Black Males(East Carolina University, July 2024) Grandy, Jody CBlack American males reported sadness and hopelessness and that everything takes an effort at a higher rate than Black women, Caucasian males, and other groups. Although the statistics related to Black males’ depression are high, their attitudes toward seeking professional psychological help remain unfavorable. Black males are often grounded and socialized in traditional masculinity and ethnic ideologies, including those that prevent professional psychological care, a normative method of coping with distress. As men, they are socialized not to self-disclose their feelings, and as Black Americans, they learn the importance of social support within the Black community.Item Embargo Defining the Metabolic and Regulatory Properties of the mdo Operon in Pseudomonas aeruginosa PAO1(East Carolina University, July 2024) Adindu, Chukwuemeka StevePseudomonas aeruginosa PAO1 is an opportunistic human pathogen that is especially problematic for individuals with cystic fibrosis and immunocompromised patients. It is a leading cause of nosocomial infections and is responsible for 10% of all hospital-acquired infections. The CDC classifies the organism as a serious threat mainly due to its emerging development of multidrug resistance. Several virulence factors contribute to P. aeruginosa PAO1 pathogenicity including hydrogen sulfide. Sulfide (HS-) at sub-micromolar concentrations protects P. aeruginosa PAO1 from antibiotic-induced oxidative damage and host-produced reactive oxygen species. However, elevated sulfide levels result in cellular toxicity and affect the organism’s ability to form a biofilm. Therefore, HS- concentrations must be tightly regulated to balance the potential toxicity with bacterial virulence. In several organisms, toxic levels of HS- are converted to usable sulfur forms by the combined actions of dioxygenases and sulfurtransferases. Increased levels of HS- results in the formation of low molecular weight persulfides which are the substrates for the sulfide oxidation enzymes. In P. aeruginosa PAO1, enzymes expressed on the mdo operon have been identified but their mechanism of action and metabolic roles have not been elucidated. In P. aeruginosa PAO1, the mdo operon expresses 3-mercaptopropionate dioxygenase (MDO) and a sulfurtransferase (ST). MDO was initially characterized as utilizing 3-mercaptopropionate (3MPA) as a substrate; however, P. aeruginosa PAO1 could not utilize 3MPA in microbial growth studies to ascertain the physiological relevance of the thiol substrate. MDO was able to oxidize 3-mercaptopyruvate (3MPR), which is a physiologically relevant substrate and can also be linked with ST activity. Even though MDO is expressed from the same operon as an annotated ST, the functional role of the ST enzyme has not been recognized. ST enzymes have conserved cysteine residues that mediate sulfur transfer from a sulfur donor to a sulfur acceptor. These sulfur donors and acceptors are usually low molecular weight thiols that are ubiquitous in cells. The ST expressed on the mdo operon has four rhodanese domains with two of the domains containing putative catalytic Cys residues (Cys191 and Cys435) with the potential to mediate sulfur transfer through an enzyme cysteine persulfide intermediate. Cys435 was the only accessible thiol in thiol assays. Results from HDX-MS investigations supported a more solvent-accessible region surrounding Cys435. The accessible thiol was identified as Cys435 in HDX-MS investigations, which corresponded to the role of this residue as the sulfide mediator. Only Cys435 formed a persulfide intermediate with either thiosulfate or 3MPR as the sulfur donor in cysteine persulfidation assays. These studies support Cys435 as the catalytic cysteine with thiosulfate and 3MPR serving as the sulfur donor. ST showed a similar affinity for 3MPR and 3MPA suggesting that each substrate could serve as a putative sulfur acceptor for the enzyme to form a persulfide. MDO was able to oxidize the persulfides of 3MPA and 3MPR, suggesting a metabolic link between MDO and ST. Although 3MPA could bind ST and serve as a substrate for MDO, it was not a viable sulfur source in growth studies. Proteomic studies were performed to identify the changes in protein expression when the organism was grown in sulfur-free media supplemented with sulfide. When P. aeruginosa PAO1 is under sulfide stress, the genes that were high in abundance were those involved in biological processes including amino acid breakdown, arginine deaminase pathway, and tRNA metabolism amongst other pathways. The data from these investigations point to the potential of the enzymes of the mdo operon to mobilize and assimilate sulfide in P. aeruginosa PAO1 thereby enhancing its viability and pathogenicity. Understanding the strategies for the acquisition of sulfur from less preferred sources and their regulation provides insights into the metabolic versatility and pathogenicity of P. aeruginosa PAO1, highlighting potential targets for therapeutic interventions.Item Embargo Validation of the Nine Item AvoidantRestrictive Food Intake Disorder (ARFID) Screen within a Pediatric Gastroenterology Clinical Setting(East Carolina University, July 2024) Al-Hammori, DeannaARFID is a relatively new psychiatric diagnosis having been introduced in the DSM-5 in 2013. As ARFID is a relatively new diagnosis, there is little research on the etiology, prevalence, outcomes, assessments, and treatments. Of the assessments available, the NIAS is currently the only free, easily accessible, and brief self-report measure of symptoms available. The validity of the NIAS has only been assessed in adult and special populations until recently when the only peer-reviewed validation of the NIAS with a pediatric population was published. This research aimed to validate the NIAS in a pediatric gastroenterology clinic using child self-report. Using a retrospective chart review, 41 participants between the ages of 8 and 17 years old were identified. Participants were split between two groups, those with ARFID and those without. A ROC curve analysis was conducted to assess the sensitivity and specificity of the NIAS. The results of the ROC curve analysis indicate that the NIAS correctly identified ARFID in the patient population beyond chance when they presented with the Picky eating subtype, but not overall.Item Open Access Characterization of RAS Protein Using Raman Spectroscopy(East Carolina University, July 2024) Aryal, MakundaRas is a family of related proteins expressed in all animal cells, which is small GTPase anchors to the plasma membrane where it regulates signal transduction for cell proliferation, growth, survival, and other cell functions. Mutation of Ras makes it lost the ability to regulate signal transduction and causes cancer. Three different types of Ras (KRAS, HRAS, NRAS) and their isoforms have been identified in different human cancers. Understanding Ras protein functioning mechanisms is crucial in developing cancer drug and cancer therapy at the molecular level, which is highly related to its primary, secondary, and tertiary structures. At present, X-ray crystallography and NMR are the two major techniques to effectively measure Ras protein structures and its conformational geometries, but they cannot measure Ras protein conformations in cells under physiological conditions. In this study, we intend to develop label-free Raman spectroscopy methods to characterize and quantitate Ras isoforms and their structural conformations with their unique finger-printing vibrational spectra in vivo and in vitro, as well as to monitor the small drug molecule’s binding with Ras molecule in live cells, which is new to Ras based cancer biology. The first part of this dissertation work is to explore the capability of near-infrared Raman spectroscopy and multivariate analysis techniques for the characterization and differentiation of Ras isoforms and their structural conformations with their finger-printing Raman spectra. We have collected Raman spectra from different Ras isoforms. We have developed a principal component analysis (PCA), a discriminant analysis of principal component (DAPC), and Raman barcode methods, and demonstrated that Ras isoforms can be differentiated by their Raman spectra. We have studied the structural conformations of Ras proteins with GDP and GTP loading. By deconvolution of Raman spectra, we were able to obtain new information about Ras conformational structures including protein’s secondary structures, hydrogen bonding condition of phenol side chain, and hydrophobic nature of tyrosine doublet for each Ras isoforms. We have applied Raman spectroscopy for the study of the specific inhibitor (ARS1620 drug) and KRAS G12C interactions, offering new insights into Ras-targeted cancer therapies. These data allow generating a library of Raman spectra of Ras isoforms in vitro, which may serve as the control and platform for developing methods to detect the Ras Raman fingerprint inside a cell. The second part is to develop a vacuum-enhanced micro-Raman spectroscopy (VERS) for the detection of analyte molecules at relatively low concentrations in an aqueous medium. Although Raman spectroscopy is a powerful technique for analyzing biomolecules, the molecular cross-section of Raman scattering is very low, and thus, high analyte concentration in hundreds of mM is typically required for normal Raman spectroscopy. Since Ras proteins are generally available at low concentration either in vitro or inside the live cells, we intend to develop a novel label-free enhanced Raman spectroscopy for the detection of proteins and other molecules at relatively low concentrations. The VERS technique relies on the increase in the molecule’s concentration within the micron-sized excitation volume of laser focus by vacuum evaporation of solvents and does not cause the alteration in normal Raman spectra. We demonstrate that an enhancement factor of ~103-104 was observed for glucose and protein samples, and the enhancement factor depends on the size of the sample holder and the volume of the liquid sample used. We show that VERS can be used to detect ciprofloxacin antibiotics in human urine at a level of 2 μg/ml. We also show that the VERS technique is particularly useful for detecting biomolecules resolved in a solvent such as dimethyl sulfoxide (DMSO) that has an intense Raman background due to the evaporation of the solvent. Traditional enhancer materials like metal nanoparticles are not needed in VERS technique. The third part is to develop the surface-enhanced Raman scattering (SERS) spectroscopy and SERS-based super-resolution Raman imaging techniques for the detection and chemical imaging of analytes at the single-molecule level. Since the intrinsic Raman scattering of Ras protein and other biomolecules has very low probability and the intra-cellular concentration of Ras is extremely low (in nanomole level), we intend to introduce nano-sized metallic particles (SERS substrate) to bind with the target molecules and use their SERS signals to detect the target molecules with an ultrahigh sensitivity and precisely determine the spatial location of the molecules. We built a home-made experimental setup that allows simultaneous observation of the Raman images of hot spots and acquisition of time-lapse Raman spectra of a single hot particle. We explored the dynamic behavior of SERS of hot particles at the single-molecule level, focusing on the influence of environmental conditions and laser power on the stability of SERS Raman signals. It was observed that SERS intensity fluctuations were more pronounced at the atmospheric pressure than at a low pressure. The experimental data further revealed that as the laser power increased (~ 8.9 μW and above), there was a notable increase in SERS signal fluctuations and blinking, probably due to thermal or photo-induced changes in nanoparticle clusters. We proved that the use of bright field microscopy and Raman imaging for tracking hotspots together with ThunderSTORM software, was effective in accurately identifying and analyzing the change in hot particle’s center position. These findings underscore the importance of precise experimental control on both laser parameters and environmental conditions to optimize SERS applications at single molecule levels, which advances our understanding of SERS at the nanoscale, promoting its application in nanotechnology and materials science.Item Open Access Improving Sleep in Young Children(East Carolina University, July 2024) Rodriguez, MarieABSTRACT Sleep disorders are a serious problem in the United States alone, affecting between 50 and 70 million individuals. Between 20% and 30% of toddlers, infants and preschoolers around the world suffer from problems with falling asleep or staying asleep throughout the night. One of the most common sleep problems in young children is delayed sleep onset (DSO). This occurs when the child has difficulty going to bed within 20 minutes. Night waking episodes, when the child wakes up at least once per night and does not reinitiate sleep independently, are another common problem. DSO and night waking episodes in children can negatively impact caregiver sleep as well. Because these children lack the ability to self-soothe, their caregiver(s) have to wake up and help them fall back to sleep. One evidence-based intervention for DSO is letting the child “cry it out”, also called “extinction”. However, some caregivers are not comfortable with this method. Other interventions include moving the child’s bedtime back by small increments until the child’s desired bedtime is reached, called fading. Fading interventions have been effective when paired with response cost, but this has only been studied in the case of one typically developing child. This pilot study tested a novel fading intervention for typically developing children between the ages of two and six. During the intervention, caregivers moved the child’s bedtime back by 15 minutes every night and woke them at the same time every morning. Sleep was monitored using ActiGraphs to objectively examine frequency of night waking episodes and how well the intervention worked over 3.5 to 6.5 weeks. By implementing this pilot study of sleep, I aimed to determine the feasibility, acceptability, and preliminary effectiveness of a sleep intervention in promoting independent sleep onset (ISO) and less frequent night waking episodes in typically developing preschool aged children with DSO. While the two caregivers who completed this intervention demonstrated that it was feasible for some, it was not feasible for the 12 caregivers who declined to participate in either part or all parts of the study. The two caregivers who completed this intervention found it to be acceptable. The intervention was also effective at reducing night waking episodes in both participants. For one participant, diaries revealed night waking episodes were reduced from five episodes during baseline (an average of one episode per night) to zero at intervention and post-intervention. For the other participant, the sleep diary revealed eight night waking episodes during baseline, three episodes during the intervention, and the caregiver reported qualitatively that night waking episodes had ceased altogether post-intervention (the caregiver did not fill out diaries during post-intervention). The intervention was also effective at promoting ISO, which was found to continue past the post-intervention phase based on a follow up email survey for both participants. Both caregivers reported a decrease in the length of time it took their child to fall asleep independently from 30 minutes at baseline to 15 minutes at post-intervention. Limitations of this study included a small sample size, homogeneity of participants, unforeseen barriers to approval of the study, including difficulties with recruitment due to the COVID-19 pandemic, and multiple barriers to participants completing the study as written in the protocol. Future studies of sleep should include larger, more diverse samples, seek to reduce caregiver barriers to participation, and increase feasibility of sleep interventions for night waking and delayed sleep onset.Item Open Access Relational Biofeedback: Exploring the Role of Social Support in the Practice of Biofeedback(East Carolina University, July 2024) Knauss, Adrian WeldonBiofeedback is a health intervention that trains people to exert control over physiological processes through real-time monitoring and feedback mechanisms (Schwartz et al., 2016). The practice promotes self-regulation and can be used to improve physical and mental health (Tan et al., 2016). However, biofeedback interventions are often conducted individually and practitioners rarely utilize the patient’s social network to assist in the development of self-regulation skills (Frank et al., 2010; Schwartz et al., 2016). This is a notable omission since research has established that social systems impact patients’ psychophysiology (Kleinbub, 2017). Therefore, the purpose of this dissertation is to explore how social support persons can be utilized in biofeedback. This concept, which the authors refer to as relational biofeedback, is an underdeveloped, but promising future direction in biofeedback. The dissertation is comprised of six chapters: (a) an introduction to the dissertation, (b) a literature review on the practice and psychophysiological underpinnings of relational biofeedback, with a special emphasis on heart rate variability biofeedback, (c) a systematic review of the literature to identify attempts to use relational biofeedback interventions to date, (d) proposed methodology for an original research study, (e) the results of the mixed-methods research study comparing individual to relational approaches to heart rate variability biofeedback with romantic partners (N = 12), and (f) a series of recommendations for clinicians and researchers, with an focus on the role medical family therapists can play in the advocacy and advancement of relational biofeedback.Item Open Access A FOOD BOX INTERVENTION FOR FAMILIES EXPERIENCING FOOD INSECURITY AND TYPE 2 DIABETES: A PILOT PROJECT(East Carolina University, July 2024) Donelan, JenniferThe negative impacts of type 2 diabetes (T2D) can be exacerbated by food insecurity (FIS), contributing towards overall familial stress, poor health outcomes, and difficulties with diabetes management. Food box interventions may reduce some barriers to healthy eating, including access to fresh produce, transportation, and food cost. The current pilot project was designed to examine the feasibility, acceptability, and satisfaction of a produce food box intervention for families impacted by T2D and FIS, as well as any changes in eating habits and perceived stress. The pilot project was shown to be acceptable to families and participants indicated that they were satisfied with the intervention. Study feasibility was negatively impacted by participant recruitment and retention. Participant eating habits did not change; however, perceived stress was shown to decrease mid-intervention before rebounding post-intervention. Barriers identified throughout the pilot study, as well as via participant response are highlighted.