Digital Commons Network^™

Enumerating Escherichia Coli (E. Coli) Concentrations And Evaluating Optical Brighteners As A Potential Indicator Of Human Wastewater Contamination In La Nana Bayou, Banita Creek, And Their Tributaries, Nacogdoches, Texas, Swastika Acharya, Matthew Mcbroom, Yuhui Weng, Yanli Zhang

Electronic Theses and Dissertations

La Nana Bayou was added to the Texas 303(d) list in 2000 after it failed to meet water quality standards set by the Texas Commission on Environmental Quality (TCEQ) for primary contact recreation due to elevated Escherichia coli (E. coli) levels. E. coli is a bacterial species commonly found in the intestines of humans and warm-blooded animals. It serves as an indicator of fecal contamination in freshwater, though its presence alone cannot identify the contamination source. Optical brighteners (OBs), chemicals found in laundry detergents, cleaning agents, toilet papers, and clothing, are unique to human wastewater. This study aimed …

Changing Globally, Acting Locally: Responses Of Coastal Plant Functional Traits To Global Change Are Mediated By Biotic And Abiotic Interactions., Shannon L. Walker

Electronic Theses and Dissertations

We live in a time of rapid global change with substantial consequences for planet-wide functioning. Local ecosystems reflect this change, yet we struggle to predict their responses. Coastal ecosystems, like dune and interdunal wetlands, have declined rapidly and predicting their responses to global change is essential for future management. Functional traits may be particularly informative as they drive species and ecosystem responses and can provide generalizable findings. This dissertation investigates how global change, especially anthropogenic nitrogen (N) enrichment, interacts with abiotic and biotic factors to affect coastal sand dune and interdunal wetland plant functional traits. First, I used a long-term …

Examining Parent Accommodation Of Anxiety And Irritability In Preschool-Aged Children., Anna Olczyk

Electronic Theses and Dissertations

Anxiety and irritability are common developmentally normative emotions in early childhood, yet are also related to risk for psychopathology in childhood, adolescence, and adulthood. Parenting behaviors, including parent accommodation, may influence this risk. Parent accommodation is the parent modification of child/family routines and/or avoidance of activities to reduce child distress and has been documented widely in the anxiety literature. Although some research has examined parent accommodation of anxiety in preschool-aged children, most research has investigated accommodation of anxiety in clinical samples of school-aged children. Further, despite high rates of co-occurrence between child anxiety and irritability, research on parent accommodation of …

Assessing Medical Decision-Making Capacity: The Importance Of Patient Values., Emilee M. Ertle

Electronic Theses and Dissertations

A medical decision-making capacity (MDC) assessment is the assessment of an individual to determine whether they can make their own medical decisions or if a proxy decision maker must make care decisions on their behalf. These assessments are necessary when individuals experience cognitive impairments which limit their ability to think through complex medical decisions. Best practice for MDC assessments is a growing area of research, with no standard approach to guide assessment planning. The current study builds upon the field’s knowledge of capacity assessments by investigating 1) what methods and measures clinicians utilize in capacity assessments, 2) what factors influence …

Promoting Metacognitive Awareness Through Exploratory Learning., Ryan J. Patrick

Electronic Theses and Dissertations

Exploratory learning engages learners in novel problem solving before direct instruction. This process is designed to lead learners to experience productive failure. Productive failure, however, has been shown to benefit learners by improving the recognition of knowledge gaps, relevant problem features, and deep structures. This allows learners to better attend to relevant information during the subsequent instruction and improves conceptual understanding. This dissertation investigates the role of metacognitive awareness during exploratory learning, in attempt to identify additional metacognitive mechanisms that support exploratory learning. Two experiments tested the theory that exploratory learning promotes metacognitive awareness in exploratory learning. Groups in both …

Effects Of Perfluorooctane Sulfonate In A Mouse Model Of Alcohol-Associated Liver Disease., Paxton Michelle Brizendine/Ames

Electronic Theses and Dissertations

Perfluorooctane sulfonate (PFOS), a pervasive environmental pollutant, has been increasingly associated with the development of metabolic dysfunction-associated steatotic liver disease (MASLD); nonetheless, its connections with alcohol-associated liver disease (ALD) have not been well studied. This study investigates the hypothesis that PFOS exposure alters hepatic metabolism, thereby leading to alterations in ALD severity. Male C57BL/6J mice were fed isocaloric control or 5% ethanol (EtOH) diet for 15 days. From day 6 of feeding, mice were concurrently gavaged with 1 mg/kg PFOS or 2% Tween-80 vehicle for 10 days, followed by a 5 g/kg EtOH binge dose. PFOS and ethanol co-exposure significantly …

Metabolic Regulation Of Cardiac Fibroblast Phenotype And Function., Collin Kleis Wells

Electronic Theses and Dissertations

Cardiac fibroblasts are central effectors of cardiac repair after myocardial infarction (MI). In response to signaling cues, they differentiate to a range of phenotypes with robust capacities to synthesize and secrete extracellular matrix (ECM) and signaling molecules. Although activated fibroblast phenotypes are associated with pronounced changes in metabolism, it remains unclear how the metabolic network upholds the effector functions of fibroblasts in the post-infarcted heart. Here, we identified that critical enzymes in the phosphoenolpyruvate (PEP) cycle, i.e. pyruvate kinase muscle-2 (PKM2) and phosphoenolpyruvate carboxykinase-2 (PCK2), are elevated in the heart after MI and examined their role in regulating post-MI remodeling …

Estimation Methods For Bayesian Exponential Random Graph Models Under The Horseshoe Prior., Pamela Linares

Electronic Theses and Dissertations

Networks are powerful tools for modeling the complexity of social interactions, biological systems, and information spread. A leading statistical frameworks for analyzing network data are Exponential Random Graph Models (ERGMs), which provide a principled approach to capturing structural dependencies. However, ERGMs remain challenging to estimate, especially in sparse or high-dimensional settings where models suffer from degeneracy and unstable parameter inference. This paper proposes a penalized Bayesian approach to ERGMs that utilizes the horseshoe prior, a sparsity-inducing global-local shrinkage prior. This prior offers robust regularization while preserving important signals, improving estimation by shrinking irrelevant parameters and reducing the impact of extreme …

My Achilles Years., Ash William Bittner

Electronic Theses and Dissertations

This dissertation is a historically and rhetorically grounded creative project exploring the traumas of war. This project is divided into three broad chapters, each using a different (and relevant) approach to cover the content contained within that chapter. The first chapter relies on that historical grounding, exploring the history of PTSD as it is currently understood, before exploring ancient Greek poetry and theater and both the historical and military contexts for each, before finally discussing modern warfare and the “Forever War” of the American War on Terror that lasted for nineteen years. With the historical grounding set, it moves into …

A Deep Learning Approach For Semantic Segmentation And Its Application On Ctc., Samir Farag Harb

Electronic Theses and Dissertations

This dissertation explores the modeling and analysis of medical images, focusing on the intricate task of colon segmentation and subsequent 3D reconstruction, which are critical steps in Computed Tomography Colonography (CTC) systems. The primary objective of this research is to develop precise segmentation approaches to enhance the accuracy of colon identification and reconstruction from abdominal CT scans. Three distinct segmentation approaches are proposed and evaluated: a Markov Random Field (MRF)-based approach, a convolutional neural network (CNN)-based deep learning (DL) approach, and a sequential episodic training with dual contrastive learning Approach (G-SET-DCL) that has a flavor of few-shot learning (FSL). To …

Linked Lives In The Riverbed: Integrating Fish Host Dynamics, Community Structure, And Demography For Freshwater Mussel Conservation., Jonathan Patrick Frommeyer

Electronic Theses and Dissertations

Freshwater mussels are long-lived benthic invertebrates that play key roles in nutrient cycling, water filtration, and habitat stability in rivers and streams. Despite their ecological importance, they are among the most imperiled faunal groups in North America, with their persistence increasingly threatened by environmental degradation and disruptions to host–parasite dynamics. This dissertation integrates host ecology, community structure, and demographic modeling to assess population viability and guide conservation priorities for mussel species in Kentucky river systems. The first chapter introduces the ecological context and conservation urgency surrounding freshwater mussels. In particular, emphasizing the need for multi-scale approaches to understand how parasitic …

Queer Convergence: Figurative Abstraction In Contemporary Art., Vincent Young

Electronic Theses and Dissertations

This thesis is an exhibition text for the exhibition of the same name held in Schneider Hall Galleries from May 15 to August 21st, 2025. This exhibition explores the work of three contemporary artists – Joshua Jenkins, Drew Scanlon, and Lalana Fedorschak – and analyzes their artwork through the lens of Queer Convergence. Queer Convergence is an exploration of abstracted images of bodies and how we can read these bodies through a queer lens, arguing that the visual language of bodily overlap, melding, and transformation shows the physical form as a site of continual change shaped by shared experience and …

Remotely-Sensed Urbanization And Local Perceptions Of Change From 1985-2024 In Southern Indiana., Marlea Ferber

Electronic Theses and Dissertations

This study is focused on the land cover change of non-built land cover being transformed into built land cover in two counties in Southern Indiana using mixed methods. Remote sensing was used to identify and quantify land cover change, and interviews were used to understand local perceptions of the physical land cover changes. The study area is situated along the rural-urban continuum with Louisville, Kentucky across the Ohio River. It is important to quantify the amount of land change conversion to built settlement as patterns and rate of urbanization help us to better manage transitions along the rural-urban continuum, but …

Dust Observations Of Occulting Galaxy Pair Vv 191., Clayton Robertson

Electronic Theses and Dissertations

The presence of dust grains as part of the the interstellar medium (ISM) in galaxies is an all-impactful entity in astronomy due its influence on light, and therefore observations. Unlike a true blackbody, dust absorbs, reflects, reddens, and scatters light within a line of sight. We quantify this phenomena with attenuation: the difference between the observed and true magnitudes of an astronomical object due to dust. Therefore, to map dust attenuation, one needs a known background source of light. In the serendipitous case of partially overlapping –occulting– galaxies, the background galaxy serves as the known light source and the transmission …

Design And Testing Method For Quality Control Of Chill Haze In Bourbon Production., Molly J. Wilburn

Electronic Theses and Dissertations

Chill haze is a quality issue in which white wisps and haze become visible in spirits when reaching sub 0℃ temperatures. Common quality control test methods rely on subjective visual tests and ambient temperature turbidity measurements. Currently there is limited access to commercial devices capable of reaching the sub 0 ℃ temperatures that are required for the formation of chill haze. This thesis focuses on the design, assembly and calibration of a custom-built turbidity meter capable of sub 0 ℃ temperatures and humidity control. The system uses an optical sensor at 90 ° to a light source to detect light …

Role Of Cardiac Ketone Body Metabolism In Myocardial Perfusion And Exercise Performance., Kara R. Gouwens

Electronic Theses and Dissertations

Cardiorespiratory fitness, a crucial determinant of overall health and a strong predictor of all-cause mortality, is largely dependent on the capacity of the cardiovascular system to deliver oxygen and nutrients. The heart, as the central pump, requires a continuous and adaptable oxygen supply, particularly during increased workload such as occurs with exercise. Impaired myocardial blood flow (MBF) in response to increased demand can lead to ischemia, limiting exercise capacity and potentially causing severe cardiac events. Interestingly, changes in myocardial metabolism and cardiac work correlate with changes in MBF. Therefore, understanding the regulation of MBF, especially the link between local cardiac …

Bleeding Out From The Redlining: An Autoethnographic Study Of Racial Equity Policy Enactment In A Large, Urban School District., Anderson Aven Cook

Electronic Theses and Dissertations

This autoethnographic study investigates the enactment and impact of racial equity policies within Jefferson County Public Schools (JCPS), a large urban school district in Louisville, Kentucky. The research is motivated by the ongoing challenges of achieving true educational equity for Black and Brown students, a struggle rooted in historical injustices such as redlining. Despite over seven years of policy implementation aimed at promoting racial equity, academic and behavioral disparities between Black and Brown students and their White counterparts have shown little improvement. Utilizing a qualitative methodology, this study employs autoethnography to intertwine personal narrative with scholarly analysis, exploring the lived …

Genes That Matter: Survival Modeling In Tcga-Brca With Treatment Interactions., David Pratt

Electronic Theses and Dissertations

High-dimensional genomic data offer both promise and challenges for identifying clinically relevant biomarkers. This study developed a parallelized survival modeling pipeline to identify genes associated with overall survival in breast cancer, with a focus on gene-by-treatment interactions and patient heterogeneity. RNA-Seq data from female patients in the TCGA-BRCA cohort were analyzed. Univariate Cox proportional hazards models were used to screen genes, adjusting for age, race/ethnicity, treatment status, and cancer stage. A LASSO-penalized Cox regression was fit across 2000 random seeds to assess feature stability. Genes were filtered by expression level, statistical significance, and hazard ratios (effect sizes) in either direction, …

Why Are Parents Choosing Forest Preschool? A Look Into Parent Choice And Outcome Expectations In A Forest Preschool Setting., Victoria M. Jones

Electronic Theses and Dissertations

As interest in alternative early childhood education settings continues to grow, Forest Preschools—programs emphasizing immersive outdoor, nature-based learning—have gained increasing attention from parents across the United States. This qualitative research study explores the underlying motivations and decision-making processes that lead families to choose Forest Preschool settings. Guided by Kurt Lewin’s Field Theory, which examines behavior as a function of person and environment, the study investigates the dynamic interplay of personal beliefs, social influences, and contextual factors that shape parental choice. Specifically, this study addresses four key research questions: (1) How do families who choose Forest Preschools gain information about preschool …

Effects Of A Speech-To-Text Assistive Technology Writing Accommodation For Students With Cerebral Palsy, Kirstin Franklin

Electronic Theses and Dissertations

Cerebral palsy (CP) is a motor disability characterized by impairments in movement, muscle tone, or posture that can also include intellectual, executive functioning, language and memory skills, and academic achievement deficits in children with CP (Centers for Diseases Control and Prevention [CDC], 2022; Levitt & Addison, 2019). These neurological consequences and motor impairments can impact written expression. The aim of this study was to evaluate the effects of a speech-to-text assistive technology (AT) accommodation that was applied to circumvent the impaired spelling and handwriting (i.e., transcription) skills resulting from CP. Three male students (Grades ranged from 6-10) with CP participated …

Evaluating Quadrupedal Locomotion In Bats: A Geometric Morphometric Comparison Of Vertebral Adaptations Across Mammals, Jessica Upham

Electronic Theses and Dissertations

Flight is the primary locomotion of bats, while quadrupedal locomotion is not often observed and is widely variable among bats. Frugivorous bats in Pteropodidae are more efficient climbers than frugivorous bats in Phyllostomidae and insectivorous bats in Vespertilionidae, while phyllostomids and vespertilionids are better at walking on horizontal surfaces. The aim of this study is to investigate whether bats with differing modes of nonflight locomotion also exhibit disparity in thoracolumbar vertebral morphology. Using geometric morphometrics, we compared the thoracolumbar vertebral shapes of these bat families with other terrestrial and arboreal mammals. The results revealed distinct vertebral shapes among bat families …

Reentry For Formerly Incarcerated Individuals: A Focus On Workforce Reentry And Recidivism In Appalachia, Margaret E. Francisco

Electronic Theses and Dissertations

Formerly incarcerated individuals face challenges to successful reentry, a critical component of reducing recidivism and improving public health outcomes. These challenges are particularly acute in rural Appalachia, where structural disadvantages such as limited economic opportunities, healthcare access, and public transportation intersect with stigma and systemic barriers related to prior incarceration. This dissertation addresses these gaps through a mixed-methods examination of reentry and recidivism, grounded in public health frameworks and focused on the unique context of rural Appalachia.

This work includes three studies. First, a PRISMA-guided systematic review synthesized qualitative research on barriers and facilitators to employment following incarceration. Findings highlighted …

An Examination Of Legal Status, Law Enforcement Perception, And Crime Victimization And Reporting Among Hispanic Immigrants, Guadalupe C. Cabrera

Electronic Theses and Dissertations

This study relied on in-depth interviews with naturalized citizens and lawful permanent resident Hispanic immigrants to explore their perceptions of law enforcement and experiences with crime victimization and reporting. Past literature has explained that the absence of legal status may deter crime reporting. We added to this body of work by investigating relationships among legal status, trust, and reporting behaviors. This study finds that direct experiences with law enforcement and acquired knowledge may be a better indicator of law enforcement trust and crime reporting compared to legal status. While most participants expressed trust in law enforcement, others felt neutral due …

Coastal Transition Zone Development Effects On Salt Marsh Ecology, Amanda Mei Pysher

Electronic Theses and Dissertations

The coastal transition zone (CTZ) is a regional gradient linking terrestrial and marine systems, comprising of the terrestrial upland, the marsh-upland ecotone, and estuarine salt marshes. Along all US coastlines, including the South Carolina (SC) coast from Little River to Georgetown, increases in anthropogenic development of terrestrial uplands have altered the historically established vegetation, and various physical, chemical, biological, and geological gradients. Despite the CTZ's ecological importance, the trickle-down effects of terrestrial upland development on associated high marsh habitats remain understudied. Data were collected from developed (DEV) and undeveloped (UND) shorelines across three SC estuarine inlets. Multilevel modeling (MLM) was …

Impact Of Aleks On Math Achievement For Students Who Were Socially Promoted, Jenifer Michelle Goff

Electronic Theses and Dissertations

This research examines the impact of ALEKS on student achievement in mathematics, specifically the correlation between mastering course concepts and preparedness for Algebra 1 as assessed by MAP RIT scores. The investigation focuses on the problem that many students lack the foundational skills necessary for success in Algebra 1 and higher-level math courses, leading to the research questions: "How does student completion in the ALEKS intervention course impact their performance on MAP?" and "How much more likely are students who completed the intervention course to be considered Algebra 1-ready based on MAP than those who did not?"

The study employed …

Perceptions Of First-Year College Students On Respect In The Classroom During Their High School Career, Jane Adele Bailey

Electronic Theses and Dissertations

This study examines the influence of teacher respect on classroom climate, student- teacher relationships, and academic performance. Through interviews with college students reflecting on their high school experiences, this research identifies specific teacher actions and communication that foster respect in the classroom. By identifying what respectful communication and actions are through the interviews, teachers will be able to use these in their classrooms.

Six themes were identified by the participants lived experiences. They are: teacher demeanor, social interaction, attitude, emotional support, instructional management and facilitation, and listening. The results gave specific actions and communication, in the eyes of the participants, …

A Tale Of Two Toxicants: Investigating The Interaction Between Hexavalent Chromium And Perfluorooctane Sulfonic Acid., Morgan Elizabeth Delnicki

Electronic Theses and Dissertations

Hexavalent chromium [Cr(VI)] and per- and polyfluoroalkyl substances (PFAS) are environmental contaminants of major public health concern. Despite commonly being found together in contaminated drinking water, no studies have considered the concomitant health effects of Cr(VI) and PFAS, specifically perfluorooctane sulfonic acid (PFOS). In vitro studies using CHO cells assessed the cytotoxicity and genotoxicity of Cr(VI) and PFAS both individually and in combination. Intracellular and extracellular Cr levels were measured with Atomic Absorption Spectrometry. PFOS was found to exacerbate Cr(VI) induced cytotoxicity and genotoxicity. Additionally, a novel in vivo model of studying the hepatotoxicity of Cr(VI) was established. Adult Hartley …

Exploring Hexavalent Chromium Exposure And Lipid Accumulation In Liver Disease., Gabrielle Celine Griffin

Electronic Theses and Dissertations

The prevalence of MASLD has doubled over the past 20 years and continues to rise. Hexavalent chromium [Cr(VI)], a top chemical hazard in U.S. drinking water, is emerging as potential risk factor for liver disease. To study the impact of Cr(VI) and high-fat diet on MASLD, we developed an in vivo model using Sprague-Dawley rats exposed to Cr(VI) in drinking water (0, 0.05, or 0.1 mg/L) and fed normal or high-fat diet for 90 days. High-fat diet significantly increased body mass, plasma lipoproteins, cholesterol, liver injury, and hepatic triglycerides, which were exacerbated by Cr(VI) exposure. Cr(VI) alone increased hepatic chromium …

Trauma Network Design Considering Patient Safety And Cost., Lin Lin

Electronic Theses and Dissertations

Trauma, as the leading cause of mortality and morbidity for those under the age of 45 in the US, incurs trillions in annual economic costs. The time-sensitive nature of trauma treatment necessitates an effective, coordinated regional trauma system to optimize patient safety. However, the financial burden associated with trauma care, especially due to low-insured population, presents a significant challenge to the financial health of trauma centers (TCs). To address critical challenges in this domain and provide much-needed insights to trauma decision-makers regarding their trauma system cost, network design, and subsidy policy, this dissertation proposes 3 contributions. First, we introduce an …

Analysis Of An Ethanol Sensitive Bmp-Nkx2.3-Fgf Signaling Pathway In Pouch Morphogenesis., Hieu Dai Le Vo

Electronic Theses and Dissertations

Craniofacial malformations lie at the heart of Fetal Alcohol Spectrum Disorders (FASD). While there is growing evidence for a genetic component to FASD, little is known of the cellular mechanisms underlying these ethanol-sensitive loci in facial development. Bone Morphogenetic Protein (Bmp) signaling pathway dependent pouch formation is a key mechanism in facial development. We have previously shown that multiple Bmp mutants are sensitized to ethanol-induced facial defects. However, ethanol does not directly impact Bmp signaling. This suggests that downstream effectors, like nkx2.3 and Fibroblast Growth Factor (Fgf) signaling, may mediate the impact of ethanol on Bmp mutants. Here, I …