Master's Theses
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Item Embargo Traps and Other Stories(East Carolina University, July 2024) Tilley, WendyThis selection of four short stories treats low-culture plots, subjects, and storylines, with high-culture rhetorical techniques. Taking as its sources material B-movies, or Portuguese plays from the 16th century, this thesis believes that the distinction between high and low art is nonexistent, another binary created where binaries do not exist. Literature is for, and made of, drunks, prostitutes, and thieves, as much as many honorable people. It is also attempts to be American, in the sense that the plots hint at violence, aberrant sex, and Christianity, the American trinity.Item Embargo The Influence of Prenatal Exercise Mode on Maternal Cortisol Levels during Pregnancy(East Carolina University, July 2024) Smith, Savannah VictoriaBackground: Cortisol is essential for regulating metabolism, immune function, and stress response. During pregnancy, cortisol levels naturally rise to support fetal growth and development. However, elevated maternal cortisol levels are linked to adverse pregnancy outcomes, such as preeclampsia and preterm birth. While exercise is known to normalize cortisol levels in non-pregnant women, its impact during pregnancy remains unexplored. This study aims to examine the influence of different modes of exercise during pregnancy on maternal cortisol levels. Methods: This study consisted of women with singleton pregnancies, who were randomly assigned to one of four groups: aerobic (AE), resistance (RE), combination exercise (CE), or an attention control group (CON). Blood samples were collected at 16- and 36-weeks gestation to measure cortisol levels. Participant exercise sessions were supervised and tracked. Results: In all evaluated exercise types (AE, RE, and CE) the participants had normal levels of cortisol, normal birth outcomes, with no adverse pregnancy outcomes, and thus were deemed safe for pregnant women. The study observed different change patterns in cortisol levels from early to late pregnancy among exercising groups. At 16 weeks, all the maternal cortisol levels had a small effect size, which suggested the group values were similar. At 36 weeks, the AE and CE groups had a small effect size, which showed no difference between those values; but in the RE group, there was a large effect size, which showed a difference. The change scores of the maternal blood cortisol levels showed CON, RE, and CE groups increased from early to late pregnancy, however AE decreased from early to late pregnancy. Discussion: This study enhances the understanding of how exercise during pregnancy affects cortisol levels. While the RE group compared to the CON group showed a moderately strong increase at 36 weeks, this can be due to the large effect size. It provides insights into safe and beneficial exercise regimens, aiming to inform healthcare professionals and expecting mothers about the role of exercise in managing cortisol levels and promoting healthier pregnancy outcomes.Item Embargo The Influence of a Digital Weight Loss Intervention on Blood Pressure Outcomes(East Carolina University, July 2024) Maloney, Kallie R. StephensCardiovascular disease remains a highly prevalent disease that is consistently among the leading cause of death for Americans (Ahmad, 2023). Managing one’s blood pressure is a prominent recommendation in preventing heart disease (Olsen et al., 2016), but over 45% of the US population is classified as having hypertension (Benjamin et al. 2019). While the treatment recommendations for hypertension depend on hypertensive stage and ASCVD risk, lifestyle modification is recommended for all. Typical lifestyle changes include weight loss, diet modification, and increased physical activity (Whelton et al., 2018). Lifestyle intervention is not without challenge, however, with physician time constraints consistently emerging as a barrier to implementation. Digital health provides an avenue for assistance with lifestyle modification, something recognized by a majority of physicians (AMA, 2022). Digital health has shown to be effective in managing various physical health outcomes, including weight loss and diet modification. Little research, however, has focused on hypertension specific goals. Digital health also serves as an opportunity to reach underserved populations, such as those from rural or low-income environments. Preliminary research indicates that digital health interventions are feasible in these populations, but little research has assessed blood pressure outcomes. The aims of the present study, therefore, were to assess the influence of a commercially available digital health intervention for weight loss, Noom, on blood pressure related outcomes, determine what factors influence blood pressure, and determine if rurality and income environment influences rate of blood pressure decrease. It was hypothesized that systolic and diastolic blood pressure would decrease over the 16-week intervention. It was also hypothesized that weight, gender, and physical activity (steps) would be associated with blood pressure. Lastly, it was hypothesized that both rural users and users living in environments with a higher proportion of individuals from low income would display slower blood pressure decrease. User’s weekly blood pressure, weight, and steps were utilized for analysis. User zip codes were used to classify users as rural or urban using secondary Rural Urban Commuting Codes. Zip codes were also utilized to estimate the proportion of individuals from low-income households (<$25,000 annually) within a user’s zip code using 2019 IRS tax data. From there, conditional growth curve models were estimated to address all hypotheses. Systolic and diastolic blood pressure significantly decreased over the 16-week intervention. Baseline weight and physical activity were significantly associated with systolic blood pressure. Lastly, rurality status and income environment were not significantly associated with different systolic or diastolic blood pressure trajectories. While many findings were as expected, rurality and user’s environmental income not significantly slowing rates of blood pressure decrease were surprising. It is possible that the present sample of Noom users do not adequately reflect the average rural individual, or individuals from low income environments. Specifically, the cost associated with Noom and the voluntary nature of inputting blood pressure could have contributed to a sample that was more motivated for blood pressure change.Item Embargo The Effect of Maternal Exercise Mode on One-month Infant Motor Skills(East Carolina University, August 2024) Lilley, AshtonABSTRACT Purpose: To determine if the mode of exercise influences 1-month infants neuromotor skills. Methods: One hundred and seventy-two healthy, pregnant women between 18 and 40 years were randomly assigned to aerobic, resistance, a combination of aerobic and resistance exercise intervention or no exercise (control) group. Women in the exercise groups performed 50 min of moderate-intensity, supervised exercise, three times per week; those in control group maintained usual activity. Neuromotor skills were measured at 1 month of age using the Peabody Developmental Motor Scales, 2nd Edition (PDMS-2). Unpaired t-tests were used to compare infants’ PDMS-2 subtest percentiles, Gross Motor Quotients, and Gross Motor Quotient percentile between groups. Results: Infants of women with a pre-pregnancy BMI less than twenty-five in the aerobic and combination groups had higher PDMS-2 scores on 3 of the 4 variables analyzed relative to infants of the resistance group and nonexercisers. Infants of women with a pre-pregnancy BMI greater than twenty-five in the resistance group had higher PDMS-2 scores on 3 of the 4 variables analyzed relative to infants of the aerobic, combination, and nonexercising groups. Conclusion: Women who exercise during pregnancy may positively influence the neuromotor development for their infants. Earlier neuromotor development is correlated with higher activity rates in children. These findings could suggest that maternal exercise during pregnancy may reduce the risk of childhood obesity since physical activity is a modifiable risk factor for obesity. Key Words: CHILDHOOD OBESITY, MOTOR SKILLS, EXERCISE, PREGNANTItem Embargo Routes of transmission of gut bacteria in R. imitator tadpoles in an experimental context(East Carolina University, July 2024) Belduque Correa, NataliaThe gut microbiota provides important capacities for the host, and the relationship between host-microbiome could affect, bidirectionally, different traits of the history life. Therefore, it is important to know how the microenvironment of living beings is shaped and what factors influence the community and composition of bacteria. The mother–to–offspring microbiota transmission has been extensively studied in vertebrates, focusing on human primates. In amphibians, the understanding of diversity and community of bacteria has been biased to skin microbiome. In this research, we study whether R. imitator mothers, a neotropical poison frog from Peru that display prolonged parental care, are transferring microbes to tadpoles by feeding them with trophic eggs. We used 16S rRNA amplicon-sequencing of the gastrointestinal tract of captive R. imitator mothers and their tadpoles. The analyses showed that composition of microbes is different between parents and offspring. Also, the composition of gut bacteria of tadpoles included different bacterial phyla usually found in gastrointestinal tract of vertebrates. Although, phyla Bacteroidetes and Proteobacteria were also found in gut of fish food experiment, it was seen that the proportion of Proteobacteria are higher in tadpoles from switching and control experiments, which can suggest that the proportion of microbes that comes from the maternal diet is similar than the proportion that comes from the environment. This supports the assumption of mother’s role in parental care is not limited, exclusively, to provide nutrient resources.Item Embargo Rewilding the River: Assessing the Environmental Effects and Regulatory Influences of the Condit Dam Removal Process(East Carolina University, July 2024) Safari, NedaThe goal of dam removal projects is to improve river ecosystems by facilitating the restoration of natural water flows, sediment movement, water temperatures, and the ability of fish to migrate. However, if the removal of dams fails to be properly managed, it can also result in the movement of significant amounts of sediment and may have additional long-term impacts on the fish population and the environment. Although numerous dams have been removed in the United States, there is still a need for a comprehensive framework that mandates long-term and in-depth assessments regarding the ongoing ecological alterations and outcomes of restoration efforts on different fish species populations. Also, the current legal and regulatory frameworks that regulate the removal of dams could hinder the ability of government agencies to monitor and manage the post-removal conditions effectively. Multiple federal, state, and municipal permits are necessary, but regulations fail to sufficiently consider unexpected outcomes or provide clear guidance for issues such as ongoing monitoring obligations and expenses. Therefore, this research has three objectives: 1) analyzing the legal and regulatory structures that regulate the process of removing dams, with a focus on identifying areas that need improvement based on the analysis of the Condit case study; 2) examining the policies and strategies that influenced the decision-making process for the removal of Condit Dam as well as their effects on the physical alterations of the river after its removal; and 3) investigating the ongoing effects of dam removal more than ten years later, aiming to determine the impact of the regulation on the river's physical and ecological response. This research uses a combination of qualitative and quantitative approaches. The effectiveness of regulations pertaining to dam removal was evaluated using the Framework for Analyzing Public Policies, with a specific focus on the case study of Condit Dam removal. To address the second objective, semi-structured interviews were conducted with 16 participants who were involved in the Condit project. The data obtained from these interviews was then analyzed using Thematic Analysis. The effects of dam removal were evaluated using descriptive statistical analysis of fish population dynamics before and after the dam removal. The analysis of the fish population indicates that both species showed fluctuations; the Fall Chinook had a more dramatic peak and subsequent sharp decrease after the dam removal because of the sediment, followed by signs of possible recovery. The population of Spring Chinook salmon has shown reduced but consistent levels, with a drop in 2019 followed by a partial recovery. In addition, the interview findings were analyzed to determine key patterns and trends in stakeholder perspectives throughout the project. By analyzing both the policy dimensions surrounding the removal decision as well as the ongoing ecological responses of the river system post-removal, this study aims to provide insights for facilitating better dam removal processes and outcomes in the future. The findings highlight poor investment of funds and monitoring initiatives for assessing fish populations. Effectively managing the need for continuous assessments, especially after major events such as dam removals, poses a continuing challenge that requires increased financial support. The study’s results suggest that cooperation and standardizing processes across regulatory bodies might enhance the efficiency of dam removal efforts while maintaining environmental protection. Furthermore, a flexible and well-financed funding structure for dam removal projects, based on comprehensive pre-removal analysis and post-removal monitoring, could improve the effectiveness of river restorations accomplished through dam removals.Item Embargo Relationships among Cumulative Life Stress, Interoception, and Psychiatric Presentations with Somatic Features(East Carolina University, July 2024) Simon, AliaInteroceptive processes involve awareness and insight into one's physiological state, as influenced by the integration of sensations detected and interpreted by the nervous system. Since interoception involves ongoing communication between the brain and the body, research is beginning to investigate if interoceptive processes are influenced by past experiences that may have disrupted mind-body communication. For the current study, we sought to investigate whether one's accumulation of severe stressors across the lifespan may interfere with one's ability to perceive the integration of internal bodily signals accurately and adaptively, contributing to interoceptive dysregulation and bodily distrust. We sought to explore whether this dysregulation would ultimately contribute to adverse mental health outcomes that feature somatization. Research examining relations between cumulative life stress, interoceptive processes, and psychiatric presentations remains in its infancy with limited investigation. The current study sought to bridge the current gap in the literature by investigating interoceptive accuracy and interoceptive awareness as a dual mediator, partially accounting for the assumed relationship between cumulative life stress and symptoms of psychological disorders with somatic features. Given that interoceptive processes are a multidimensional construct, we examined interoceptive awareness (attentional style when interpreting and attending to internal bodily signals) and interoceptive accuracy (appraisal of one’s perceived accuracy when interpreting bodily signals). Key variables of interest were explored within emerging adults, given that this is a salient developmental period marked by identity exploration with a greater propensity for the emergence of psychological presentations. A total of 575 undergraduate students at a large Southeastern university completed an online survey that examined cumulative life stressor severity, interoceptive processes (interoceptive awareness and interoceptive accuracy), and screeners assessing for symptoms of psychological disorders with somatic features (i.e., social anxiety disorder, panic disorder, depression, somatic symptom disorder, post-traumatic stress disorder, eating disorders). To our surprise, interoceptive accuracy did not demonstrate significant relationships with stress or symptoms, failing to account for the relationship between stress and symptoms. In contrast, interoceptive awareness demonstrated a significant inverse relationship with stress and symptoms while also acting as a protective mechanism, reducing the translation of stress to symptoms. Ultimately, our findings support the protective utility of one’s ability to attune to bodily senses with a mindful, non-judgmental mindset as captured by interoceptive awareness. Gaining insight into interoceptive patterns associated with common psychological disorders provides insight for tailoring transdiagnostic psychometric tools and interventions informed by the mind-body connection.Item Embargo Nitrogen and Phosphorus Remediation in Mesocosm Floating Treatment Wetlands receiving Municipal and Aquacultural Wastewater(East Carolina University, July 2024) Barnes, Matthew ThomasAs populations shift and grow throughout the world, the amount of organic waste generated directly and indirectly by humans has increased. Wastewater treatment operations play a key role in helping to keep our natural surrounding water bodies clean by removing nitrogen (N), phosphorus (P), and other contaminants of concern from wastewater. Floating treatment wetlands (FTWs) may offer a low-cost energy efficient supplemental treatment option to existing wastewater treatment operations by removing nutrients from wastewater through plant uptake, adsorption, and microbial processes. The purpose of the study was to determine the N and P reduction capabilities of mesocosm FTWs from both domestic and aquaculture wastewater. The extent to which FTW plant species diversity (monoculture vs polyculture) influenced N and P removal was investigated, and the N and P removal dynamics throughout the growing season were characterized. Water samples and plant measurements were collected every week over the course of 14- and 10-week trials during 2022 and 2023, respectively. Mesocosm FTWs were located at the Greenville Utilities Commission Wastewater Treatment Plant for domestic wastewater research and the Marine Aquaculture Research Center of North Carolina State University for aquaculture wastewater research. For both trial 2 studies of the MARC and GUC-WWTP, there were no statistically significant differences among treatments of nitrogen (N) or phosphorus (P) removal. However, for all trials N was removed more effectively than P. The GUC-WWTP had removal ranges of 0.12 to 0.32g/m2/day for N and 0.01 to 0.08 g/m2/day for P. The MARC trial 1 had removal ranges of 0.49 to 0.95 g/m2/day for N and 0.02 to 0.04 g/m2/day for P whereas the trial 2 study has removal ranges of 0.21 to 0.43 g/m2/day for N and 0.004 to 0.02 g/m2/day for P. Overall, the late summer growing season (MARC 1) had higher nitrogen removal rates compared to late spring and early summer (MARC 2). For the GUC-WWTP, there was more phosphorus removed compared to the MARC, for trial 2. Yet all achieved positive removal rates in summation of both locations. The purpose of this study was to characterize the N and P removal efficacies of monoculture vs mixed species plantings of floating treatment wetlands from wastewater. Additional research into native wetland plant species and their nutrient removal potential could aid in finding alternatives or supplements to high energy-dependent treatment methods at wastewater treatment facilities. Future studies should investigate how water hydraulic retention times, continuous flow vs batch systems, and seasonal plant growth characteristics impact nutrient removal efficacies. Other studies into plants with more P removal efficacy and plants with more nutrient specific uptake rates could be effective depending on the nutrients being removed.Item Embargo LATE PLEISTOCENE PALEOENVIRONMENTAL CHANGES IN THE LOWER NEUSE RIVER BASIN, NORTH CAROLINA, AND IMPLICATIONS FOR RELATIVE SEA LEVEL AND COASTAL EVOLUTION(East Carolina University, August 2024) King, Jessica LynnThe coastal plain of eastern North Carolina evolved through the changes associated with late Pleistocene rapid relative sea-level oscillations during Marine Isotope Stages 5 to 2. The sea-level highstand deposits of MIS 5 and MIS 3 have been previously studied in eastern North Carolina; however, certain regions have had little to no data collected, which makes determining the areal extent of facies and associated depositional environments challenging. To overcome these limitations and better understand the spatial and temporal variation of sea-level fluctuations, geophysical and geological data from the lower Neuse River Basin have been analyzed. These data reveal the presence of multiple paleoenvironments with distinctive sequences corresponding to MIS 5e, MIS 5a, and MIS 4. The chronological framework, determined using optically stimulated luminescence dating, provides sediment age estimates ranging from 123.5 (± 7.2) ka to > 56.8 (± 4.1) ka. DS-5e is composed of eastward thickening shelly sand lithofacies. This sequence contains two distinct foraminiferal assemblages. Samples dominated by Elphidium excavatum, Ammonia parkinsoniana, and Elphidium mexicanum are overlain by samples also containing Buccella inusitata, Nonionella atlantica, and Rosalina sp. Additionally, pollen samples collected within DS-5e show a trend of cooler conditions in the lowermost sample of the core to likely warmer than modern conditions in the uppermost collected sample. This transition from low to higher diversity foraminifera assemblages, warming climate conditions, and shelly marine deposits is indicative of a transgressive environment, interpreted as a high salinity estuary becoming an inner shelf environment. DS-5a is characterized by burrowed laminated sand, as well as sandy mud and is barren of foraminifera, with the exception of one sample. Lithofacies show an upward-fining succession transitioning from flaser to wavy tidal bedding. One pollen sample from DS-5a suggests conditions ranging from modern to slightly warmer than present. With apparent tidal bedding, the absence of foraminifera, and warm climate conditions DS-5a is potentially indicative of coastal tidal flat deposits. The lithofacies of DS-4 are characterized by medium to fine-grained burrowed laminated sand and sandy mud, with all samples being barren of foraminifera. Regression during MIS 4 likely exposed sediment from a shallow marine shoal in cores south of the river, where aeolian forces likely reworked the sand into dunes. Comparing these facies across the Neuse River Basin with similar studies in the region offers valuable insights into how coastal North Carolina's geomorphology responded to changes in relative sea-level during the late Pleistocene.Item Embargo Integration of Cervical Nervous Tissues into a Head-Neck Finite Element Model for the Investigation of Radiculopathy(East Carolina University, July 2024) Bruns, Rachel ElaineRadiculopathy of the spine is a prevalent chronic disorder caused by a wide number of pathologies, affecting up to 10% of individuals over the age of 50 (Mansfield et al., 2020). It is caused by compression of the nerve roots within the spinal column and intervertebral foramen of the spine as they travel from the spinal cord distally to the rest of the body. While cervical radiculopathy is prevalent within the common aging population, recent concern has been raised at the increasing incidence of reported neck pain in fighter pilots, helicopter pilots, and crewmen (Ang & Harms-Ringdahl, 2006; Harrison et al., 2015; Posch et al., 2019; Walters PL et al., 2012). Repetitive loading activities such as wearing heavy helmets can cause compression of the spine which could be contributing to chronic neck pain, decreasing quality of life and safety while operating aircraft (Mansfield et al., 2020; Van den Oord et al., 2012). Due to the ethical concerns of researching loading the neck in human experiments, mechanisms of nerve root pain and potential radiculopathy can be investigated using finite element (FE) modeling, which is a computational method that utilizes constitutive mathematical equations to simulate mechanical behavior of one or multiple components under loading conditions. While there has been development of many FE models of the cervical spine for different applications (Ah Shin et al., 2016; Khuyagbaatar et al., 2017, 2018; H.-J. Kim et al., 2009; Mihara, 2017; Xue et al., 2021, 2023), to our knowledge, no previous studies investigated cervical radiculopathy, nerve root compression, or the soft-tissue interaction within the spinal canal and intervertebral foramen (IVF). In this thesis, the focus was on the development and implementation of the nerve root geometry and surrounding ligaments into a full model of the cervical spine. The Nerve CSM (Cervical Spine Model) was developed in this thesis by adding nervous tissue to an existing head-neck model, the VIVA Open Human Body Model (OpenHBM) published by (Östh et al., 2017). The VIVA OpenHBM already contained a skull, vertebrae, intervertebral discs, vertebral ligaments, passive muscles, and surrounding soft tissues. The nervous tissue modeled and incorporated into the VIVA OpenHBM to create the new Nerve CSM in this thesis encompassed gray and white matter of the spinal cord, cerebrospinal fluid, dura mater, root sheaths, spinal nerves, nerve roots, dorsal root ganglions, nerve rootlets, denticulate ligaments, foraminal ligaments and epidural ligaments. Geometry was created in SolidWorks (SOLIDWORKS 2023, Dassault Systèmes-SolidWorks Corporation, Waltham, MA, USA) using anatomical measurements from the literature the part’s meshes were generated in ANSYS. These meshes were incorporated into the VIVA OpenHBM in LS-Prepost (LS-PrePost 4.10, © 2024 DYNAmore GmbH, an Ansys Company, Hauptniederlassung Stuttgart) , where the nerve rootlets, denticulate ligaments, foraminal ligaments, and epidural ligaments were created using discrete tension-only spring elements. Validation of the Nerve CSM’s global head and spinal cord kinematics was performed by replicating the 2.3 m/s whiplash simulation published by (Östh et al., 2017) and the flexion/extension simulations published by (Stoner et al., 2019). The global head kinematics of the Nerve CSM in the 2.3 m/s whiplash simulation did not change substantially compared to the VIVA OpenHBM. Additionally, the correlation score for the time response of the Nerve CSM compared to the experimental data was similar to the VIVA OpenHBM, thus, it is reasonable to conclude that the addition of the nerve geometry did not considerably alter the global kinematics of the VIVA OpenHBM. The results of the spinal cord kinematic validation of the Nerve CSM demonstrated that the spinal cord during flexion and extension of the head moved within the bounds of variation presented in the experimental data (Stoner et al., 2019), pointing to a conclusion that the Nerve CSM demonstrates suitable spinal cord kinematics for a healthy participant. Future work will encompass the integration of the Nerve CSM into subject-specific pilot neck models to investigate the effect of cervical spine compression and flight related loading conditions on the interaction between the nerve roots and surrounding tissues.Item Embargo Identification of a novel autonomous role for Ecdysone Receptor during Drosophila ovarian germ cell differentiation.(East Carolina University, July 2024) Jung, Lauren ElizabethA tightly regulated network of signals coordinates the division of Drosophila germline stem cells (GSCs) and differentiation of their daughter cells to produce viable oocytes. The steroid hormone, ecdysone, is known to promote GSC self-renewal; however, due to lack of compatible genetic tools, potential autonomous roles in the germline have not been fully evaluated. Ecdysone elicits a diverse array of transcriptional responses by binding to a heterodimeric complex composed of Ecdysone Receptor (EcR) and Ultraspiracle (Usp). To elucidate whether EcR facilitates autonomous reception of ecdysone in the germline, we built germline-compatible genetic tools to manipulate EcR levels or activity. Depleting EcR mRNA or loss of EcR ligand binding in the germline caused a loss of GSCs over time, demonstrating that it is necessary for GSC self-renewal. Further, over-expressing either EcR.A or EcR.B1 isoforms resulted in undifferentiated germ cell tumors and decreased numbers of GSCs. This is a ligand-dependent function of EcR, as over-expression of EcR that cannot bind ecdysone suppressed tumor development. By restricting over-expression to later stages of the germline, we found that EcR is sufficient to induce tumors only when over-expressed in the GSCs and early daughter cells. In tumorous ovaries, stem-like cells were also identified outside of their normal stem cell niche, suggesting that these cells remain competent to respond to BMP signals. Using single-cell RNA-sequencing to compare EcR over-expressing and Tkv over-expressing ovaries, we found remarkably similar transcriptomes in heterogenous populations of germ cells. These data suggest that EcR promotes differentiation of germ cells by directly regulating components of the BMP signaling pathway and that low levels of EcR expressed in wildtype GSCs are sufficient for ligand-dependent activation of an ecdysone-responsive transcriptional program. Altogether these data reveal a novel, autonomous role of EcR in GSC maintenance and regulation of differentiating daughter cells.Item Embargo Identification and Quantitation of Cannabinoid Solute-Column Interactions Using the Hydrophobic-Subtraction Model to Predict Separation in High-Performance Liquid Chromatography(East Carolina University, July 2024) Tunnell, Heather KayeThe Hydrophobic-Subtraction Model (HSM) has been widely used for identification of similar and orthogonal chromatography columns since its inception in 2002 but only had limited uses as a predictive tool. Recent refinement of the model has improved the prediction accuracy to a level that offers promise for use in high-performance liquid chromatography (HPLC) separation development. The HSM quantitatively describes the parameters affecting solute retention on HPLC columns including hydrophobic, steric, hydrogen-bond, cation exchange, and dipole interactions. To demonstrate the process, 16 cannabinoid compounds were chosen as the test solutes due to increasing interest and applications. The HSM was used to identify and quantify the various cannabinoid solute retention parameters based on actual retention of each solute on a set of calibration columns with previously quantified column retention parameters. The resulting solute parameters were used to predict relative retention of each cannabinoid on over 550 columns in the HSM column database. A sorting system was then developed to rank the columns. Overall, this Thesis demonstrates the application of the HSM to cannabinoid compounds starting with identification of the best columns for the separation of these solutes.Item Embargo Exploring Black Women's Experiences with Perinatal Loss, Grief, and Coping(East Carolina University, July 2024) Saufley, AnnagraceThis study's purpose is to better understand the lived experiences of Black women who have experienced perinatal loss using Stroebe and Schut’s (1999) Dual Process Model of Coping with Bereavement as a guiding framework. A descriptive phenomenological design was used to conduct semi-structured one-on-one interviews with a purposive recruited sample. The sample consisted of five Black mothers who had experienced a perinatal loss between 20 and 36 weeks gestation within the past five years. Colaizzi’s (1978) framework was used to conduct data analysis. Each woman’s unique story is detailed, following a description of the three emergent themes and seven theme clusters. The three emergent themes found were medical negligence, social relationships, and transformation. These findings build upon existing literature and offer implications for healthcare and research professionals. Future research directions are also explored.Item Embargo Examining Microbial Transfer Between Human and Non-Human Primates Using a One Health Approach(East Carolina University, July 2024) Smith, DejahThe health of humans, wildlife, plants, and their environments are interconnected, and this concept is fundamental promoting public health and conservation goals globally. The One Health approach defines the relationship of humans, plants, animals and our shared environments, positioning health at the core. This approach aids conservation management as facilities can look at health holistically, focusing not only on the health of the captive populations but also of the staff, volunteers, and the public. This is particularly important for the conservation of endangered species, such as lemurs. In Madagascar, lemur populations represent 20% of the worlds primate species and are endangered due to habitat fragmentation, deforestation, and anthropogenic factors. Captivity gives endangered populations a chance at rehabilitation and humans the opportunity to observe and learn from their behaviors, physiology, and development. Although captivity holds many benefits, we must think about how factors introduced by conservatory settings influence the health of captive animals and the humans who interact with them. Past studies have documented the transfer of microbes is documented to occur between humans and their pets. In this study, I examined the extent to which microbiome exchange occurred between human and non-human primates observed at the Duke Lemur Center (DLC) in Durham, North Carolina, USA. I hypothesized that (i) lemurs exposed to human microbiomes frequently (i.e., daily) and housed in captive only settings will exhibit altered gut microbial compositions and higher microbial diversity of human associated taxa than free-ranging lemurs that interact rarely with humans and maintain spatial proximity or no human contact. I also hypothesized that (ii) humans working in Duke Lemur Center departments with high levels of contact between NHPs will harbor an altered skin microbiome, composed of bacterial taxa associated with lemur species. To test this hypothesis, I collected fecal samples from four lemur populations, which included blue-eyed black lemurs (Eulemur flavifrons), Coquerel’s sifakas (Propithecus coquereli), crowned lemurs (Eulemur coronatus), and ring-tailed lemurs (Lemur catta). This research was approved by the East Carolina University’s Institutional Animal Care and Use Committee (IACUC) protocol number: AUP#P110. Human forehead and hand skin swab samples from 13 interns over five timepoints were provided voluntarily from the DLC summer interns who worked in various departments across the facility. These protocols were approved by East Carolina University’s Intuitional Review Board (#UMCIRB 22-000802). The gradient of lemur-human interaction intensity across DLC department was done to ensure a variety of frequency of interaction with the lemur populations. There were seven husbandry interns, four research interns, one education intern and one paleo-primatology intern. I extracted genomic DNA from human skin and lemur fecal samples and conducted 16S rRNA gene PacBio HiFi long-read sequencing. Results showed that human-associated taxa were observed to a greater extent in the gut microbiomes of enclosed lemurs where there was more frequent contact with humans. Variation in diversity was observed in the free-ranging, terrestrial population, Lemur catta, who I observed in the field as approaching gated areas and trails that people often occupied. In human forehead samples, taxa associated with the phylum Bacteroides were observed. Both lemur fecal samples and human skin samples harbored Bacteroides, demonstrating the presence of non-endemic microbes in lemur guts. In humans, this revealed that animal caretakers can exhibit altered microbial diversity due to contact intensity with lemurs since taxa from the Bacteroides phylum were observed in high relative abundance on the human skin microbiome of the animal husbandry interns only, which is contrary to past studies. Understanding the mechanisms of microbiome transmissions among humans and non-human primates is especially important for the conservation of captive non-human primates and the health of the humans managing captive populations. Transmission of microbes among humans and non-human primates can provide key information on how to best serve these captive populations and manage facilities to ensure the best outcomes for rehabilitation and conservation of species.Item Embargo Elucidation of The Roles of Metal Ions in Misfolding and Aggregation of TTRwt and TTR-V30M Associated with ATTR Amyloidosis(East Carolina University, July 2024) Burton, KelleyMisfolding and aggregation of transthyretin causes a range of diseases, many of which are caused by mutations and destabilization of the protein. Known diseases related to the protein include cardiomyopathy, polyneuropathy, and transthyretin amyloidosis, along with other ailments 1,2,3. The mechanism by which these diseases and many others occur is currently unknown. Through previous studies, metals have been shown to induce aggregation of these proteins in which case it is hypothesized to have an impact on the mechanism’s pathway 4,5. Specifically, Zn2+ ions at significantly higher levels have been observed to induce ex-vivo TTR aggregates in patients affected by amyloidosis compared to those with no current signs of the disease5. The effectiveness of Ca2+ ions in triggering the neurodegenerative process linked to polyneuropathy is crucial in understanding the role of the metal 5. Each of these metals has shown potential possibilities of their specific roles in interactions with transthyretin. Through this study, Zn2+ and Ca2+ ions were used throughout different experiments. WT TTR is a known native form of transthyretin that becomes unstable over time in the structural form1. This protein will be used in comparison with TTR-V30M as it is one of the most common mutations with an association with familial amyloid polyneuropathy (FAP)3. In this thesis, biophysical techniques such as aggregated kinetics, circular dichroism, and isothermal titration calorimetry were used to examine the effects of the metal ion binding. The aim of this study is to investigate the effects of the metal ions on the structure and dynamics of the protein associated with misfolding and aggregation. The biophysical analyses revealed the metal ion bindings induced local structural/ dynamical changes of the protein, promoting misfolding and aggregation.Item Embargo Elucidation of the Roles of Metal Ions in Misfolding and Aggregation of Pathogenic TTR Variants Associated with ATTR Amyloidosis(East Carolina University, July 2024) Irving, RobertTransthyretin (TTR) is a homo-tetrameric transport protein that is responsible for carrying the thyroid hormone, thyroxine (T4) and retinol (vitamin A1) via retinol binding protein in both human plasma and cerebrospinal fluid. The native TTR tetramer is highly stable but can be destabilized under certain conditions such as single-point mutations, acidic pH, and elevated metal concentrations. Destabilization of the tetramer results in its dissociation into monomers leading to misfolding, aggregation, and amyloid fibril deposition in various soft tissue organs eventually causing a set of diseases with cardiomyopathic and neuropathic manifestations known as Transthyretin Amyloidosis (ATTR). The deposition of wild type derived amyloid fibrils leads to a non-hereditary form of ATTR known as ATTRwt. With symptoms manifesting as both polyneuropathic and cardiomyopathic, this condition affects approximately 25% of the male population above the age of 80 and is the primary cause of death for supercentenarians. However, it is the hereditary transthyretin amyloidosis (ATTRv), caused by significantly increased rates of aggregation due to single point mutations, that are of particular concern. There are over 120 amyloidogenic variants of TTR that significantly increase the pathogenicity of TTR aggregation. These variants are primarily cardiomyopathy and polyneuropathy causing, though many variants lead to amyloidosis with mixed phenotype. In addition to this, many patients with either cardiomyopathy or polyneuropathy report ocular, GIT, and renopathic manifestations along with their primary phenotype. The most aggressive TTR variants cause significant damage to the central nervous system, leading to progressive dementia, ataxia, and stroke-like symptoms. Two TTR variants will be investigated in this study. The variant L55P, which replaces the lysine at position 55 with a proline, is the most pathogenic TTR mutation and often manifests with mixed phenotypes leading to varying combinations of cardiomyopathic and polyneuropathic symptoms. The variant V122I, replacing the valine at position 122 with an isoleucine is the most common mutation in the United States, carried by approximately 4% of African Americans and is primarily cardiomyopathy causing. With the presence of zinc found in ocular TTR amyloid extracts and microcalcification in cardiac extracts, it has been theorized that these physiological metals may play a more key role in ATTR pathogenesis, like those in Alzheimer’s related proteins. As such, experiments were developed to observe the effect zinc and calcium on TTR aggregation under physiological pH. Understanding the roles these metals play in vitro can offer insight into what might be occurring in vivo. Additionally, since there are currently only therapies associated with stabilizing the native TTR tetramer, determining other factors in TTR amyloid formation can create opportunities for multiple approaches to treatment.Item Embargo Electrochemical Detection of Polyphosphate Accumulation by Phosphate Accumulating Organisms for Wastewater Treatment(East Carolina University, July 2024) Cobb, Davis DInorganic phosphates are a very common additive to fertilizers used in industrial agriculture. While these additions result in larger healthier crop yields the runoff from these macronutrients ends up within local water ecosystems. The discharge of phosphate to water systems can lead to eutrophication and long-term damage to the local environment. To treat phosphate, local wastewater treatment systems (WWTP) often use bacteria to remove phosphate from the water. These phosphate treatment organisms are termed phosphate accumulating organisms (PAO) and sequester phosphate by converting it into long chains of polyphosphate. The efficiency of this process can vary due to myriad factors; therefore, the ability to monitor if the biological processes are occurring normally is a significant WWTP need. To this end, an electrochemical biosensor was developed using Layer-by-Layer (LbL) methodology to immobilize films containing Pseudomonas putida, a model PAO, to detect polyphosphate uptake following soluble phosphate exposure. The bacterial films were exposed to electroactive methylene blue and phosphate with electrochemical monitoring using square wave voltammetry to determine methylene blue reduction currents. Currents at several potentials (vs. SCE) increase as a function of phosphate exposure, which were significantly elevated in the presence of P. putida vs. E. coli films. ICP-MS was used to show that P. putida sequesters phosphorus in significantly higher amounts than E. coli, which shows that the electrochemical output is due to poly-P accumulation on the electrode surface. The sensor was challenged with interfering ion solutions and at varying temperatures to model conditions that might be encountered at the WWTP. Overall, this study lays the groundwork for the eventual biosensor use to measure PAO health and function at WWTP.Item Embargo DEVELOPMENTAL NEUROTOXIC EFFECTS OF SELECT PER- AND POLYFLUOROALKYL SUBSTANCES (PFAS) IN A MOUSE MODEL(East Carolina University, July 2024) Trowse, Kellyn AmberConnections between the nervous and immune systems, particularly those formed during development, can be perturbed by exogenous agents such as per- and polyfluoroalkyl substances (PFAS). PFAS have been used extensively in industrial and consumer products to resist heat, oil, and water. Their production and use have led to widespread environmental contamination, with a notable occurrence in the Cape Fear River in North Carolina of the United States (U.S.). Many PFAS studied to date have been implicated in adverse health effects in humans, including increased risks of some cancers, weakened immune response, liver damage, and developmental effects. Despite recent regulatory efforts for some PFAS, gaps remain in knowledge about less well studied PFAS, especially those found in the Cape Fear River and with respect to neuroimmune effects. In this study, a series of experiments to investigate developmental neuroimmune effects of PFO5-DoA (0, 0.005, 0.05, or 0.5 mg/kg) or GenX (0, 1, 5, 10 mg/kg) in B6C3F1 mice exposed from gestational day one through 17 were conducted. A homing behavior test was conducted on postnatal day (PND) 10 in GenX pups and tissue samples were collected at PND 21 and PND 56. Brain sections collected from the prefrontal/frontal cortex were stained with ionized calcium binding adaptor molecule 1 (IBA1) to visualize microglial numbers and percent area covered brain and interleukin 1 beta (IL-1) to estimate pro-inflammatory cytokine staining intensity. Average brain weights and relative brain and body weights were not statistically different for either PFO5-DoA or GenX groups. In the homing behavior test, pups exposed to 5 or 10 mg/kg had less success in finding home bedding squares than counterparts exposed to 0 or 1 mg/kg. In PND21 brains, the average number of microglia and percent area covered by microglia in mice exposed to 0.05 mg/kg of PFO5DoA were significantly decreased compared to control mice. Additionally, the average percent area covered by IL-1 staining for mice exposed to 0.05 mg/kg of PFO5DoA were significantly decreased in both PND21 and PND56 brains. Overall, while this study did not find statistically significant developmental neuroimmune effects of GenX or PFO5DoA, the potential for these PFAS to affect neuroimmune development cannot be ruled out as effects may be long-term, affected by sex hormones, and/or occur outside of the 56-day experimental lifespan of this study. Further research is needed to analyze differences between microglial abundance and phenotype early in life (from PND0-30) compared to late in life (PND60-112).Item Embargo Chronic Low Dose Toxicity of Acrolein in C. elegans Mitochondria(East Carolina University, July 2024) Yan, LisaAcrolein (ACR) is a chemical of interest in the pathology and progression of mitochondrial disease and disorder. Chemical exposure to ACR may occur exogenously due to the use of herbicides or burning of fossil fuels, or endogenously as a by-product from various metabolic pathways. Several studies focus on the impact of high dose acute exposure of ACR with various model organisms, including live rats and mice, human spermatozoa, and several cell culture models. These models do not address the consequences of long term or chronic, low dose exposures and impacts on progeny. For these reasons, the model C. elegans was ideal because of its established genome, ability to self-fertilize or sexually reproduce, ability to yield three hundred progenies in its lifetime, and its short and understood lifespan. We hypothesized that C. elegans would experience mitochondrial dysfunction when chronically exposed to low doses of ACR, particularly with the 15 μM concentration. Based on previous research indicating another electrophilic aldehyde, 4-hydroxynonenal (4-HNE) inhibits SDH activity by forming a protein adduct with the redox subunit of SDH, we predicted that ACR may inhibit complex II (SDH) activity through protein adduct formation. We also predicted that ACR may also decrease lifespan and fecundity across generations of nematodes. To test our hypothesis and aims, we utilized C. elegans in experiments incorporating lifespan and fecundity assays, performed a histochemical stain to qualitatively measure SDH activity, used RT-PCR targeting specific genes related to oxidative stress and SDHA-1, and attempted to isolate mitochondria to perform SDH activity assays measured with spectrophotometry. Our results from the lifespan and fecundity assays suggested that low dose, chronic ACR exposure may decrease lifespan and fecundity in C. elegans. We also learned that C. elegans will attempt to leave the agar plate at ACR concentrations of 75 μM and 100 μM. Our RT-PCR results showed an upregulation in SDHA-1 and SOD-3 transcription in C. elegans after a 24-hour exposure to 100 μM ACR. These results suggest that higher doses of ACR may cause oxidative stress or damage to the mitochondria and SDH. Further experimentation may help better determine the interaction between ACR and the flavonoid subunit of SDH.Item Embargo Characterization of pelvic floor and genitourinary tissue in a preclinical model of classical Ehlers-Danlos Syndrome(East Carolina University, July 2024) Kamath, SoumyaClassical Ehlers-Danlos syndrome (cEDS) is an inherited connective tissue disorder characterized by collagen abnormalities, leading to tissue fragility. Individuals with cEDS often experience urinary incontinence, pelvic pain, and sexual dysfunction, with these symptoms occurring at a higher prevalence in women (73-89%). This subtype of EDS arises from mutations in the collagen type V (COL5a1) gene, pivotal in fibrillogenesis regulation. The goal of our study is to determine the role of collagen V in the genitourinary tissue of both male and female col5a1 heterozygous mice. We hypothesize lower collagen V levels in cEDS mice would lead to more frequent voiding, decreased bladder contraction, and decreased genital tissue contraction. In chapter two, we attempted to characterize the bladder and vaginal function of the col5a1 heterozygous (HET) mice at 16-weeks by comparing them to their wild-type (WT) counterparts. We found no disparity in voiding frequency or bladder contraction between the two genotypes. However, we noticed that the HET mice exhibited lower bladder contraction rates upon the release of endogenous neurotransmitters. Interestingly, in the vagina, they displayed higher contraction responses to adrenergic stimulation and were more sensitive to nitic oxide mediated relaxation. We also assessed contractility of the iliococcygeus skeletal muscle of the pelvic floor and found no changes between the HET and WT mice. In chapter three, we repeated these experiments with male col5a1 heterozygous mice, focusing on bladder and penile smooth muscle function. Our findings mirrored those of the females as both genotypes voided at comparable rates. Additionally, both genotypes had no change in carbachol mediated contractions. However, the HET male bladders consistently contracted at lower rates to electrical field stimulation (EFS) which is mediated by the release of endogenous neurotransmitters. Interestingly, their penises exhibited higher contraction rates in response to adrenergic stimulation and showed no difference in relaxation rates. In conclusion, our findings suggest that the col5a1 heterozygous mouse model holds considerable potential as an animal model for replicating the genitourinary issues observed in clinical cEDS. Our study has established a foundational framework for future research endeavors to further understand the pathophysiological mechanisms and assess potential therapies to improve cEDS urogenital symptoms.