Digital Commons Network^™

Evaluating Alpha Spending Functions Applied To Observational Time-To-Event Analysis, Moses Torgbenu

Electronic Theses and Dissertations

This thesis explores the theoretical foundation of the alpha spending approach and extends its application beyond the conventional setting of randomized controlled trials (RCTs) to observational studies with time to event analyses. In these less structured environments, key design parameters such as the total number of events are often unknown, posing challenges for the standard implementation of sequential analysis methods.

Through simulation studies, this research delivers several important contributions. First, it presents a modified approach that uses calendar time to define the timing of interim analyses while relying on event-based information to estimate the correlation among test statistics. This adjustment …

Diagenesis And Controls On Porosity And Permeability In The Upper San Andres Formation Of West Texas, Jack Butcher

Electronic Theses and Dissertations

West Texas reservoirs on the Central Basin Platform (CBP) are dominated by Permian-age carbonate deposits, significantly contributing to petroleum production. The Upper Permian-aged San Andres Formation, composed primarily of dolomite and limestone, is a prolific reservoir. This study assesses diagenetic influences on porosity and permeability within the San Andres Formation along the northern CBP. Two cores from the Monument 4-2 and Peterson 1 wells in West Texas were analyzed using core descriptions, thin section petrography, XRD, XRF, and MICP. Results indicate that dolomitization enhances porosity, with intercrystalline and moldic porosity being dominant, while late-stage cementation and compaction reduce permeability. XRD …

An Evaluation Of Key Components Of Natural Resource Camps, Undergraduate Persistence And Success In Natural Resources, Brandy Bishop

Electronic Theses and Dissertations

This study explores the key components that connect natural resource camps, undergraduate persistence, and overall success through gainful employment within the natural resource industry. The aim of this study was to assess early interest and attitudes towards natural resource career pathways and how education interventions shape students’ career outcomes thus leading to overall success. A longitudinal mixed method design was used combining Conservation Careers Camp survey data (n = 39) with institutional records for Forestry majors (n =655) in the Arthur Temple College of Forestry and Agriculture on the Stephen F. Austin State University campus. Quantitative data was analyzed through …

Empowerment Through The Sisters Lifting As We Climb Network: Examining The Organization’S Impact On Black Women, Sharnay Hearn Davis

Electronic Theses and Dissertations

This phenomenological case study examines the role of empowerment within the “Sisters Lifting as We Climb Network” through the experiences of Black women participants in Pittsburgh, Pennsylvania. Utilizing in-depth semi-structured interviews, the research investigates the organization's origins, evolution, and social support mechanisms that foster empowerment, as well as participants' experiences with programs and activities over the past nine years. Additionally, the study identifies areas for organizational improvement to further enhance participant empowerment.

The findings of this research support the empowerment theory framework by clarifying the preconditions, processes, and outcomes of empowerment within the Network, which fosters sisterhood and enhances participants' …

Stand Strucuture Of Planted Stands In Storm-Water Retention Basins, Jason Lanza

Electronic Theses and Dissertations

Trees assist in stormwater retention basin functionality as efficient sources of water removal, and determining stand structure and leaf area of forests can be a measure of their effectiveness. The structure of forest stands on these basins managed for runoff mitigation has received little attention. We investigated the structure and species composition/diversity (tree and herbaceous) of planted, managed stands and naturally regenerated stands on stormwater retention basins managed by Harris County Flood Control District in Harris County, Texas. We determined stand structure variables (trees per hectare, basal area per hectare, quadratic mean diameter, relative density, average tree height, and percent …

Simultaneous Application Of Multiple Process Control Rules, Tran B. Ngo

Electronic Theses and Dissertations

Statistical Process Control (SPC) charts are tools used in quality control to monitor and analyze the stability of a process over time. This study evaluates the effectiveness of eight individual Western Electric rules, also known as WECO rules, and the various combinations of these rules with Shewhart rule (or WECO rule 1) to SPC charts. As more rules are added to a process control scheme with Rule 1, there is a trade-off: a higher false out-of-control signal rate but an increase in sensitivity, that is the ability of a specified process control scheme to capture a true out-of-control signal. This …

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 …

Beyond The Individual: A Dyadic Mixed-Methods Study Of Work–Life Balance In Entrepreneurial Households., Juliana Binhote

Electronic Theses and Dissertations

Entrepreneurs operate at the intersection of work and family systems; yet, their experiences with work–life balance (WLB) remain underexplored—particularly in relational contexts. While existing research highlights the psychological demands of entrepreneurship, it often overlooks how family dynamics shape entrepreneurs’ experiences of balance, conflict, and boundary management. Guided by boundary theory, conservation of resources theory, and the goal attainment balance model, this dissertation investigates the question: How do entrepreneurs experience and make sense of their work-life balance? To answer this question, I designed a dyadic exploratory mixed-methods study. In Study 1, I conducted in-depth interviews with family business entrepreneurs and their …

An Exploration Of Lgbtq+ Runner Motivation And Constraints., Michael Clemons

Electronic Theses and Dissertations

Running offers extensive benefits beyond physical fitness, encompassing mental, emotional, and social advantages. However, LGBTQ+ individuals face unique challenges in participating in the running community, which remains predominantly White, cisgender, and heterosexual. With the LGBTQ+ population in the U.S. growing, there is a need to understand their motivations and barriers to participation in running events and training groups. This study explores these motivations using self-determination theory, comparing LGBTQ+ and non-LGBTQ+ runners to identify differences in driving factors such as social connectivity, self-esteem, and competition. Additionally, it examines barriers LGBTQ+ runners face, ranging from structural obstacles to intrapersonal challenges, and how …

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 …

Reclaiming Space: Unhoused Population And Their Use Of Public Libraries., Marcellos Desmond Jackson

Electronic Theses and Dissertations

This study explores how unhoused individuals navigate and utilize the spatial dynamics of public libraries, with a specific focus on how they assert agency into the public space. Public space is examined at the institutional level and through the influential roles of individual workers. Public libraries serve as both refuge and resources for unhoused individuals, and this study highlights the complex dynamics that arise within them. Drawing on observations and informational informal interviews, I examine how unhoused people utilize and navigate the physical space of a public library in a large metropolitan area. I find that unhoused people adapt to …

Therapeutic Potential Of Sglt2 Inhibitors In A Repeated Love Dose Cisplatin Model., Dianet C. Sanchez

Electronic Theses and Dissertations

Cisplatin is a potent chemotherapeutic, thirty percent of patients develop Acute Kidney Injury (AKI). These patients are ten times more likely to develop chronic kidney disease (CKD). Sodium-glucose-cotransporter-2-inhibitors (SGLT2i), FDA approved for diabetes, has shown protection in multiple mouse models of AKI-CKD. We hypothesize SGLT2i can protect the kidney in a model of repeated low dose cisplatin with/without cancer. B6:129 mice with/without lung adenocarcinoma (Lung-adeno) were treated daily with SGLT2i dapagliflozin (10mg/kg)/vehicle control. After seven days, weekly cisplatin (7mg/kg)/vehicle control was initiated for 3-4 weeks. Following final cisplatin dose, kidney function, injury, fibrosis, inflammation was assessed. SGLT2i treatment attenuated alterations …

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 …

Migratory Patterns Of Juvenile Shortfin Makos (Isurus Oxyrinchus): Evidence Of A Nursery In The Western North Atlantic, Julia A. Crews

Electronic Theses and Dissertations

Shortfin Makos, Isurus oxyrinchus Rafinesque, 1810, are lamnids that have a global distribution in temperate and tropical oceans. Locations of critical early life history events including birthing and nursery areas are unknown or unconfirmed for most populations. The objective of this study was to identify if a nursery area for Shortfin Makos in the northern waters of the Mid-Atlantic Bight using the criteria articulated by Heupel et al. (2007). Satellite tags were used to track the movement of juveniles (<200 cm TL, n=7) up to 5 months. Tag detections (n=882) confirmed that young makos stay in continental shelf waters of the northern Mid-Atlantic Bight off Long Island through the meteorological summer (June–August) and early meteorological fall (September–October) when sea surface temperatures are 18–23°C. There was clear migratory movement from juveniles once sea surface temperatures fell below 15°C. During late fall, some young sharks moved south towards Cape Hatteras, North Carolina, while one shark moved east up to 1,800 km into the open north Atlantic Ocean into meteorological winter. These movement data of juvenile Shortfin Makos combined with multi-year catches and sightings (2018–2024) provide strong evidence for a nursery area in the northern Mid-Atlantic Bight. By identifying a nursery area for Shortfin Makos, knowledge gaps that currently exist for this vulnerable species and support effective management can be closed.

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 …

Comparison Of Nutrient Concentrations And Primary Production Indicators Across Plume Fronts, Taylor Dishon

Electronic Theses and Dissertations

Coastal buoyant plumes carry low-salinity waters containing particulate and dissolved terrestrial materials with an abundance of nutrients into the coastal ocean, including inorganic nitrogen and phosphorous. Plume fronts act as transport barriers created from the convergence of a fresher plume with an older, saltier plume or with ambient waters, leading to potential accumulation of phytoplankton and nutrients. This accumulation creates an optimal environment for primary production. The primary goals of this study were: to investigate the distribution of and potential relationships between nutrient concentrations and chlorophyll a across plume fronts of the Winyah Bay River Plume, and examine potential relationships …

Site Fidelity, Seasonality, Movement, And Fish Associates Of Sand Tigers Carcharias Taurus In North Carolina, Ara L. Mcclanahan

Electronic Theses and Dissertations

Sand tigers Carcharias taurus are mackerel sharks with a disjunct global distribution in tropical and temperate seas. In the northwest Atlantic, sand tigers migrate along the coast of the eastern United States from the Gulf of Maine to Florida and occupy structurally complex benthic habitats. The long-term, underwater camera installation, SharkCam, at Frying Pan Tower, off Cape Fear, North Carolina, USA, sits atop an expanse of hard bottom reef frequented by sand tigers. The citizen-science platform Spot A Shark USA (SAS USA) uses images of sand tigers to identify and track individuals. This study utilized image encounters from SAS USA …

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, …

Effects Of Training With Different Set-Repetition Configurations On High-Intensity Exercise Endurance And Acute Recoverability, Wesley Gawel

Electronic Theses and Dissertations

This study aimed to evaluate how high- (3x10) versus low-repetition (3x2) resistance training affects (1) muscular strength-endurance and (2) immediate recovery after a high-intensity exercise effort (HIEE). Fourteen college-aged participants (10 males: 24.5 ± 4.9 yrs, 1.76 ± 0.05 m, 86.56 ± 6.90 kg; 4 females: 23.0 ± 2.8 yrs, 1.58 ± 0.09 m, 62.19 ± 5.96 kg) completed a 4-week training program and were divided into two groups: G2 (3x2; 5 males, 2 females) and G10 (3x10; 5 males, 2 females). All subjects performed back squats to failure at 67.5% of baseline 1RM. Repetitions (REPS) and volume load with …

An Exploration Of Factors Influencing Sophomore-Year Persistence At A Regional Institution In Southern Appalachia, Jonathan W. Mitchell

Electronic Theses and Dissertations

The purpose of this qualitative and interpretative phenomenological study was to explore factors that participants identified as playing roles in their persistence through their sophomore years at a regional university located within Southern Appalachia. Research on second-year retention efforts is far lacking compared to first-year retention efforts. Reflecting the heavy emphasis placed on the first year, there is also more research on first-year retention. However, students can feel a sharp decline in support entering sophomore year, making that just as critical of a transition. Student retention has been emphasized in higher education since its inception, as an institution’s goal in …

Investigating The Multiple Enzyme Complex In The Carotenoid Biosynthesis Pathway, Mercy Mormor

Electronic Theses and Dissertations

In nature, plant carotenoids are 40-carbon isoprenoids with polyene chains that may have double bonds. They are vital components of all photosynthetic organisms, playing several roles in the plant cell, including photosynthesis, pigmentation, phytohormone synthesis, signaling and photoprotection. In this study, we investigated protein-protein interactions among key enzymes involved in the carotenoid biosynthesis pathway using the Bimolecular Fluorescent Complementation (BiFC) assay. Our results revealed several interactions that suggest a coordinated regulation of enzymatic activity within this pathway, highlighting potential regulatory complexes that influence carotenoid production. The study also highlights the pivotal role of Zeta-Carotene Isomerase (Z-ISO) as a key regulatory …

Examining The Lived Experiences Of International Students At East Tennessee State University, John The Baptist Anodjo

Electronic Theses and Dissertations

This research investigates the lived experiences of international students at East Tennessee State University (ETSU), specifically examining how they navigate social, academic, and structural challenges. Through in-depth interviews with 20 international students from a variety of nationalities, I analyzed issues related to legal status, housing, food insecurity, healthcare, and social integration. I found that students encounter barriers due to immigration policies, financial constraints, and limited access to essential resources. Additionally, international students benefit significantly from support provided by campus services, community organizations, and their social networks, which play a vital role in their adjustment process. While institutional resources are beneficial …

Gut Passage Time In Small Mammals: Influences Of Small Mammal Traits, Digesta Phase, And Particle Morphology, Noah G. Hale

Electronic Theses and Dissertations

Dispersal is crucial in maintaining healthy ecosystems, but little is known about mechanisms influencing fungal spore dispersal by animals. We aimed to develop a more mechanistic understanding of the influence of fungal spore traits and small mammal traits on gut retention time. We fed three species of small mammals (shrew, mouse, vole), which differ in gut morphologies, digestive strategies, and activity a combination of markers including: liquid digesta phase (CrEDTA), small particle (fungal spores with diverse morphologies), and large particles (glitter and beads, representing plant cells and seeds, respectively). We found that hindgut fermenters selectively retained the liquid markers, spores …

Cattle Regenerative Grazing Effects On Bat Activity In Southern Appalachia, Seth Morelock

Electronic Theses and Dissertations

Livestock farming accounts for about 70% of agricultural activity, with continuous grazing as the dominant conventional practice. However, this method often degrades biodiversity and ecosystem health through overgrazing. Regenerative grazing practices offer a potential ecologically sustainable approach to cattle management. Insectivorous bats are known to use agroecosystems for foraging and roosting habitats, offering an opportunity to assess their response to regenerative grazing. Using passive acoustic monitors, we evaluated the response of bats to cattle within regenerative grazed farms in East Tennessee, USA. Overall bat activity declined when cattle entered and exited paddocks, except for the tri-colored bat (Perimyotis subflavus …

"No One Leaves For Free": A Media Analysis Of The Lived Experiences And Cumulative Impacts Of The Flint Water Crisis., Jordan Leigh Gatewood

Electronic Theses and Dissertations

In April 2014, the city of Flint, Michigan changed their municipal water source from Lake Huron to the Flint River. The effects of this change have been felt far and wide as news broke across the nation that this water was contaminated with lead and residents of Flint were getting sick. This research analyzes 170 news articles from three local and three national news outlets over a 10-year span, 2014 to 2024, to determine how community voice is presented in news media to portray the lived experiences and cumulative impacts of the Flint Water Crisis. Applying a Critical Environmental Justice …

Mixture Effects On Metal Accumulation In The Asian Clam, Corbicula Fluminea, Mark A. Huff

Electronic Theses and Dissertations

Field collected Corbicula fluminea were exposed to trace level copper, lead, and zinc with the aim of examining the preferential accumulation between the soft tissue and shell. Metal levels were based on those in a permitted industrial effluent. At 1X effluent and 2X effluent exposure levels, copper was found to preferentially accumulate in the clam soft tissue, lead was found to preferentially accumulate in the clam shell, and zinc was found to excrete back into the diluent after preferentially accumulating in the clam soft tissue. When exposed as a mixture at 1X effluent levels, copper and lead were found to …

Deaf Faculty Members’ Experiences In Higher Education Institutions, Stephanie Proctor Horvath

Electronic Theses and Dissertations

Deaf faculty members bring diverse perspectives to higher education, yet their experiences remain underexplored in academic research. The critical first year of teaching can shape their career experiences, revealing both opportunities for growth and systemic barriers. The purpose of this study was to understand deaf faculty members’ experiences, focusing on their transition into academic roles, the accommodations provided in their workplaces, and the challenges they faced. This study employed a qualitative phenomenological design, utilizing semi-structured interviews with 15 Deaf faculty members, whose teaching experience ranges from 1 to 30 years. In the reflexive thematic analysis and AI-coding of this data, …