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Controls On Nutrient And Sediment Export In A Non-Perennial Agricultural Stream, Kathleen Cutting

Graduate Theses and Dissertations

Climate change is expected to increase flow variability and intermittency in streams, changing the magnitude and timing nutrient and sediment delivery. This may exacerbate water quality issues in agricultural landscapes, where nutrient and sediment inputs are often elevated. Elevated nutrients can drive eutrophication in downstream waterways, and excess sediment loss can decrease primary productivity. Non-perennial headwater streams are particularly vulnerable to the impacts of climate change and agriculture as they serve as key sites for nutrient cycling at the terrestrial-aquatic interface. Despite their importance, the interactive effects of agriculture and stream intermittency, as well as unpaved roads in rural watersheds …

Effectiveness Of Maternal Bovine Appeasing Substance Administered To Newly Received, High-Risk Stocker Calves, Elle Johnston

Animal Science Undergraduate Honors Theses

Stocker cattle purchased at auction can be susceptible to disease due to the stressors associated with the auction process. These cattle are labeled “high-risk” due to their compromised immune system during transportation, handling, and vaccination processes. The objective of this study was to determine the efficacy of a maternal bovine appeasing substance, FerAppease, on growth performance and behavior of stocker cattle. Male beef calves (n=80) were purchased at auction and transported to the University of Arkansas Division of Agriculture Savoy Research Complex Beef Stocker Unit. Steers and bulls were of varying age, breed, and temperament. Upon arrival to the facility …

Silver Nanoparticles In Ammonia Sensing And Photovoltaics, Madhuka Liyanage

All Dissertations

Nanocomposite films (NCF) containing silver nanoparticles (AgNPs), separated by thin layers of silica/poly-4-vinylpyridine/polyvinylpyrrolidone, were fabricated via drop casting, spin coating, dip coating on glass substrate and drop casting on nylon filter membranes. The more uniform films were produced by drop casting on nylon filter membranes due to their solvent wicking properties. The films demonstrate electrical conductivity that varies in response to moist ammonia and water vapors. The changes in conductivity are attributed to hydrogen bonding between ammonia and water molecules with the silica/polymer layers, as well as the direct adsorption of ammonia onto the silver surface. Notably, NCFs with polyvinylpyrrolidone …

Qualitative And Quantitative Analysis Of New Psychoactive Substances And Related Metabolites Using Liquid Chromatography-Ion Mobility-Mass Spectrometry (Lc-Im-Ms), Ralph Aderorho

All Dissertations

The increasing prevalence of novel psychoactive substances (NPS) in illicit drug markets has posed significant challenges for forensic and clinical toxicology, primarily due to the structural similarity and diversity among these compounds. This dissertation investigates the application of advanced liquid chromatography-ion mobility-mass spectrometry (LC-IM-MS/MS) techniques, using the high-resolution Structures for Lossless Ion Manipulations (SLIM) platform and the drift tube ion mobility spectrometry (DT-IMS), for the qualitative and quantitative analysis of various types of synthetic opioids, synthetic cannabinoids, psychedelics and xylazine. By combining IMS separations with mass spectrometry and targeted chemical derivatization, this work enhances the ability to distinguish and characterize …

Development Of Rolipram Loaded Pgp Nanoparticles For Spinal Cord Injury Repair, Zhen Liao

All Dissertations

Spinal cord injury (SCI) leads to devastating neurological deficits due to primary mechanical damage and secondary injury mechanisms, including inflammation, oxidative stress, excitotoxicity, and inhibitory scarring, which collectively impede neural regeneration. One key aspect of SCI pathology is a significant reduction in cyclic adenosine monophosphate (cAMP) levels, primarily due to increased phosphodiesterase (PDE 4) activity. As a ubiquitous second messenger, cAMP regulates key signaling pathways, including protein kinase A (PKA) / cAMP response element-binding protein (CREB) and exchange protein activated by cAMP 2 (EPAC2). Therefore, restoring/increasing cAMP level is one of the major therapeutic strategies to reduce neurotrauma and restore …

Rhetorics Of Vigilance: Refracting Discourses In Technologies Of Self-Managed Health & Wellness, Haley Swartz

All Dissertations

Rhetorics of Vigilance explores the limits of feminist health rhetorics by examining technologies that promote women’s self-managed health and wellness practices. By establishing a corpus of personal health technologies and associated texts including mobile health applications, pelvic floor training devices, and perimenopause information shared on social media, this dissertation analyzes how discourses refract––redirected and often distorted––to implicate women in persistent self-monitoring. Drawing from interdisciplinary scholarship on women’s health from feminist rhetorical studies, rhetorics of health and medicine, science and technology studies, and digital studies, I theorize rhetorics of vigilance as a framework through which women understand and interpret issues …

Development Of Translational Microscale Systems To Interrogate How Biophysical And Biochemical Cues Alter The Phenotype Of Hormone Positive Breast Cancer, Braulio Ortega Quesada

All Dissertations

Cancer is a complicated disease and one in every three diagnoses are women with breast cancer. Recent research shows that the progression of cancer depends strongly on interactions with other non-cancerous cells and non-cellular components. Metastasis, the spread of cancer to other parts of the body, is a key step in cancer progression and makes treatment harder, leading to poor response to treatments culminating in death in ~90% of patients. This dissertation focused on creating a series of microdevices as novel pre-clinical models of breast cancer. Two different devices were fabricated to (1) study how exposing cancer cells to the …

Understanding How To Cultivate Culturally Relevant Dispositions Among District Science Coordinators And Science Teachers, Meredith L. Schwendemann

All Dissertations

At the center of the discussions about equity in science education is the importance of defining and articulating what is meant by equity, diversity, and social justice. Despite recent efforts to improve equity in science education, inequities in science education persist. District science coordinators, science teachers, and science teacher educators are key players in the movement toward more equitable science learning and instruction. The purpose of this three manuscript dissertation was to explore the ways in which science teacher educators are working to promote culturally relevant dispositions within science teachers (Paper 1/Chapter 2), examine how district science coordinators are approaching …

The Effect Of Storyline Units On The Self-Efficacy And Science Identity Of High School Multilingual Learners, Kristin Ambrose

All Dissertations

Science can be a complex subject for multilingual learners (MLLs) because it requires investigating science concepts through modeling and analysis in addition to reading and writing skills. This complexity often leaves teachers unsure of how to support the MLLs, leading to MLLs missing out on grade-appropriate content and science experiences. Storyline instruction uses 3D instruction to teach science content necessary to explain a real-world anchoring phenomenon. Storyline instruction grounds learning in real-world contexts through anchoring phenomena and provides coherence for students throughout the lessons. This mixed methods study aimed to discover the impact of storyline units on the self-efficacy (SE) …

Biophysical Studies Of Nucleic Acid - Small Molecule Recognition, Andrea Conner

All Dissertations

The presented work is a collection of studies performed to examine small molecule recognition of nucleic acids. Recognition of nucleic acids was examined using two types of small molecules: aminoglycosides and Hoechst dyes. Chapter One focuses on established experimental techniques (i.e. absorbance, isothermal titration calorimetry, flow cytometry, cell microscopy, etc.) in small molecule recognition of nucleic acids. The emphasis of studies in the group has been on two focus areas. (i) Thermodynamic characterization of mixed A-form and B-form DNA or RNA conformation with aminoglycosides, particularly neomycin-class. (ii) Characterization of new Hoechst-morpholine (HT-MO) derivatives’ interactions with nucleic acids.

Focus area (i) …

The Genomic Landscape And Prognostic Impact Of Kras, Stk11, And Smarca4 Mutations And Co-Mutations On Survival Outcomes In Non-Small Cell Lung Cancer, Peter Manolakos

All Dissertations

Non-small lung cancer (NSCLC) accounts for 85% of lung cancer cases, and Kirsten rat sarcoma viral oncogene homolog (KRAS), Serine/Threonine Kinase 11 (STK11), and SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily A, member 4 (SMARCA4) mutations and co-mutations have been increasingly recognized for their potential prognostic significance. However, clear knowledge gaps remain regarding which treatments should be selected for patients who present clinically with KRAS/STK11 or KRAS/SMARCA4 co-mutations, as outlined in Chapter 1. Despite significant clinical development advancements in immunotherapy and targeted therapy, a deeper understanding of the influence of these genomic …

Learning Through Online Participation: From Breakout Rooms To Discord, Makayla Moster

All Dissertations

For software development teams, teamwork is an essential part of their day-to-day lives. However, due to the aftermath of the COVID-19 pandemic, more companies have allowed employees to have more hybrid and remote work options than before. As more companies are adopting hybrid and remote workstyles, we need to ensure that we are preparing the next batch of young software developers to conduct teamwork in remote and hybrid settings. In this dissertation, I address the tools students use for teamwork and how to improve their teamwork inside and outside of the classroom. I present my research on improving student experiences …

Toward The Application Of Natural Language Processing In Electronic Health Record Analysis For Taxonomy Development, Latoya Mcdonald

All Dissertations

Electronic health records (EHRs) are pivotal resources for nurse practice because they increase the timeliness and reliability of patient information at the point of care and support access by multiple healthcare providers and the individual patients themselves. However, it is widely recognized that data extraction from EHRs is challenging due to the variability in the language used in clinical care notes and the lack of standardized terminology across healthcare systems. The broad objective of this dissertation is to develop taxonomy-based classification models for nursing care by applying feature engineering approaches to EHRs that include nursing care of ostomy patients following …

Development Of Small-Molecule Inhibitors For Bacteroides, Naegleria, And Toxoplasma Microorganisms And Synthesis Of N-Heterocycles From Thiolated Ene-Ynes And Azodicarboxylates, Samuel Kwain

All Dissertations

Humans and microorganisms are intricately interconnected, with microbes constituting an essential component of human biology and ecology. This interdependence necessitates a delicate balance between leveraging beneficial microbes and mitigating the impact of harmful ones. The human gut microbiome, home to trillions of microorganisms, predominantly comprises commensal species that support health. However, dysbiosis within this ecosystem has been linked to serious diseases. For instance, an overrepresentation of Bacteroides species is associated with Type I diabetes mellitus (T1D) and various chronic gut disorders, including ulcerative colitis, inflammatory bowel disease, celiac disease, and colorectal cancer. Similarly, Naegleria fowleri, a free-living amoeba, causes …

Exploring Community Change Of North American Stream Fish Communities Due To Species Introductions, William K. Annis Jr

All Dissertations

The introduction of nonnative species has facilitated global changes in beta diversity, and these changes have been coined biotic homogenization (loss in beta diversity) and differentiation (gain in beta diversity). Homogenization represents a key conservation threat. Therefore it is imperative to understand the processes that allow nonnative species to establish and how these species contribute to beta diversity change. In this dissertation, I assess three key challenges exist in our ability to address these goals. One challenge is that we have inconsistent support among hypotheses of invasion drivers due to context dependency. Context dependency can arise due to differences in …

Mapping Teacher And Librarian Perspectives Through A Qualitative Descriptive Study Of Book Bans In South Carolina, Jennifer Gallman

All Dissertations

This study analyzed findings from four data collection pieces with Critical Discourse Analysis, in which participants met in focus groups to discuss their experiences with book bans and curriculum censorship. The five focus groups included Upstate middle school English teachers, Upstate high school English teachers, Upstate middle school librarians, Upstate high school librarians, and participants from the Midlands and Lowcountry of South Carolina. There were two primary research questions and two sub-questions: (1) What do educators and librarians in grades 6-12 say about how power functions in engaging or challenging current curricula and book censorship trends?; (1a) How do middle …

Ex Vivo Multiplex Knockdown Of Angptl3 And Cypor In Hepatocytes As A Novel Cell Therapy For Familial Hypercholesterolemia, Callie D. Clark

All Dissertations

Inherited metabolic diseases (IMDs) affect approximately 1 in 800 individuals. The only curative treatment for IMDs is liver transplantation. However, transplantation carries significant risks, including organ rejection and a lifelong need for immunosuppression. Therefore, gene editing has emerged as a promising alternative to liver transplantation for treating IMDs.

Familial hypercholesterolemia (FH) is and IMD characterized by elevated LDL-C levels resulting in premature cardiovascular disease. CRISPR-Cas9-mediated gene editing to disrupt the gene encoding angiopoietin-like 3 (ANGPTL3) in the liver represents a novel therapeutic approach for FH. Nonviral delivery performed ex vivo is safer than systemic delivery because gene editing is in …

Ceramic Membrane Evaluation Via Automated Filtration Systems For Water Treatment And Resource Recovery, Weiming Qi

All Dissertations

Membranes are an advanced and mature water and wastewater treatment technology. Membrane fouling is a key difficulty for all membrane filtration processes, leading to significant attention in the literature over the years. A common problem in laboratory-scale membrane research is that the testing methods in the laboratory are often quite different than industrial applications due to the limitations of manual experimental setups. An automated membrane filtration apparatus was built in the lab to solve this problem by allowing long-term filtration, frequent backwash and CIP, and high-accuracy operation. The filtration system achieves different cleaning strategies for both theoretical research and practical …

Perspectives On Clinical Oncogenomics: Secondary Germline Variants Associated With Tumor Genomic Profiling In Community Cancer Care And Advanced Practitioner Oncogenomic Proficiency, Sarah Moncado

All Dissertations

Precision medicine in oncology is defined by the sequencing of tumor genomic variants that can be used to identify targeted treatment for patients. Secondary pathogenic and likely pathogenic germline variants (P/LPGVs) can incidentally be detected on tumor genomic profiling (TGP). With the rise in precision medicine over the past 15 years, secondary P/LPGVs on TGP have been an increasingly important clinical issue. However, there are factors that can lead to misidentification and underreporting of P/LPGVs. Germane to this clinical practice issue is healthcare provider oncogenomic literacy and proficiency.

A scoping review was conducted to evaluate the variability of the prevalence …

A System And Method For Measuring Spatially Varying Surface Appearances With A Study Of Feathers, Jessica Baron-Lis

All Dissertations

Real-world materials, particularly biological structures such as feathers exhibit complex appearances that vary spatially across their surfaces. The field of computer graphics provides a means of understanding such surfaces through material modeling which uses both analytical models and data acquired from light-surface interactions. There are many efforts within the past decade in measuring materials for graphics, but common limitations in these works include not accounting for spatially varying properties and reliance on neural networks and synthetic datasets.

Feathers from modern birds present diverse appearances due to how light interacts with their unique hierarchical microstructures. Variations in those structures lead to …

The Administrators’ Role In Teacher Retention And Their Role On Teachers’ Perceptions Of School Climate At An Exemplar Title I School: A Qualitative Study, Stephen W. Brown Iii

All Dissertations

This study looks at how principals affect teacher perception of school climate and teacher retention at Title I schools. While teacher retention and school climate have historically been issues at Title I schools, the issue has been exacerbated by the COVID-19 pandemic. This qualitative study explored an elementary school in South Carolina through the lens of Critical Systems Theory. According to publicly available data, this school was an anomaly among Title I schools regarding the climate and teacher retention, with both measures being extremely high. To explore these phenomena, semi-structured interviews were conducted with both the teachers and administrators at …

Identification And Characterization Of Intermediate Phenotypes To Decipher Genetic Architecture Of Stalk Lodging Resistance In Maize (Zea Mays L.), Bharath Kunduru

All Dissertations

Maize is a key contributor to global food security and incurs severe yield losses due to stalk lodging, the permanent displacement of plants from an upright growth habit due to mechanical damage to the stem (stalk). Stalk lodging resistance, an indicator of the stalk ability to resist lodging, is a complex trait and determined by several structural, geometric, and material properties of stalks, collectively referred to as intermediate phenotypes, whose identity and genetic framework are poorly understood. Therefore, progress in resolving the genetic architecture of stalk lodging resistance was impeded by a lack of standardized phenotyping methodologies and a poor …

Leadership Matters: The Impact Of Transformational Leadership And Mattering On Job Attitudes And Perceived Performance, Chelsea E. Robbins

All Dissertations

Mattering refers to the sense that one is significant and valued by others, which has been linked by a small but growing body of research to key work-related outcomes, including job satisfaction, organizational commitment, and job performance. This study examines mattering among Basic Science Medical Educators (BSME), a group potentially vulnerable to low workplace mattering due to limited leadership support and isolation from communities of practice. Consideration for follower well-being is important across many leadership theories, and transformational leadership behaviors overlap highly with behaviors thought to increase mattering. Survey responses from BSME and a general workforce sample were analyzed to …

Understanding The Genetic And Metabolic Underpinnings Of Complex Traits In C4 Grasses, Manwinder Singh Brar

All Dissertations

Maize (Zea mays L.) and sorghum (Sorghum bicolor (L.) Moench) are two important cereal crops cultivated worldwide for food, animal feed, and industrial products. Productivity of these crops is significantly impacted by various biotic and abiotic stresses, such as diseases, insect pests, drought, salinity, and heat. Among factors influencing crop performance under stress, the regulation of leaf longevity plays a critical role in determining yield. Leaf senescence is a highly regulated process essential for nutrient remobilization through the degradation of cellular components in aging leaves, but premature or accelerated senescence reduces photosynthetic efficiency and yield. Staygreen, a phenotype …

Spatial Variaiton In Host-Associated Microbiota, Daniel Malagon

All Dissertations

Many organisms rely upon the internal and/or external microbial communities they harbor. Microbial communities which depend upon other organisms for survival are known as host-associated (HA) microbial communities. HA microbial communities differ in diversity and composition from surrounding environmental microbiota and are generally less diverse than surrounding soil microbiomes. Although distinct bacterial profiles exist between host and environment, microbial scale dispersal often links the two. For this reason, host and environmental microbial communities can be correlated (e.g., dominant taxa in HA microbiota are dominant in the host microenvironment or vice versa). Eukaryotic hosts act as islands for HA microbiota. Unlike …

Investigate The Use Of Nucleic Acids As Pesticides To Manage Major Pests And Pathogens Of Crops In South Carolina, Prasanna Valavanur Shekar

All Dissertations

The sugarcane aphid (SCA, Melanaphis sorghi), first discovered on grain sorghum in late 2013, has gradually become a major insect pest of sorghum. It inflicts significant damage to the crop year after year, causing millions of dollars in losses throughout the sorghum-producing regions of the United States. Similarly, Armillaria root rot—also referred to as oak root rot—is a major cause of decline in peach (Prunus persica) production in the southeastern United States. This disease is caused by Armillaria mellea and Armillaria tabescens. Current management practices for controlling M. sorghi include the use of synthetic pesticides, resistant varieties, and regular scouting. …

Design And Characterization Of Lignin-Based, Thermoresponsive Soft Composites With Improved Mechanical And Transport Properties, Missoury D. Wolff

All Dissertations

In an attempt to reduce reliance on petroleum-based polymers, lignin – an abundant biopolymer – has gained popularity as a sustainable alternative. However, research on lignin-containing soft composites – i.e., hydrogel (bio)composites – has largely been heuristic, providing limited insight into the fundamental structure-processing-property relationships that govern performance improvements in this emerging class of ‘green’ soft composites. As such, this dissertation presents a systematic investigation of how lignin molecular weight (MW), composite composition, and the concentrations of crosslinker and accelerator impact the mechanical and transport characteristics of soft composites composed of lignin, poly(N-isopropylacrylamide) (PNIPAm), and poly(vinyl alcohol) (PVA).

In the …

Understanding Conversion Of Long Chain Fatty Acids In Anaerobic Digestion Systems, Julia Ann Funk

All Dissertations

Anaerobic co-digestion with fats, oils, and grease (FOG) waste can increase energy production due to the high methane potential of lipids. However, adding FOG can lead to operational issues caused by accumulating saturated long-chain fatty acids (LCFA). My research explored why saturated LCFAs are often the primary intermediate that accumulates and the microbial sensitives of the populations responsible for their degradation. In each batch or semi-continuous experiment, all intermediates of FOG degradation, including LCFAs, volatile fatty acids (VFAs), Hydrogen gas (H₂), and endpoint methane production, were paired with temporal quantitative polymerase chain reaction (qPCR) of the Syntrophomonas genus …

Amyloid Aggregation And Mitigation, Zhenzhen Zhang

All Dissertations

The buildup of protein in tissues and organs plays a major role in unfunctional several serious diseases, including Alzheimer’s disease, Parkinson’s disease, and Type 2 diabetes, each tied to specific proteins that form harmful amyloid deposits. Amyloid aggregation typically follows a sigmoidal kinetic curve, beginning with a slow lag phase, followed by rapid fibril growth, and eventually reaching a plateau where mature, stable fibrils are formed. However, the early stage of aggregation remains particularly difficult to capture experimentally due to the highly dynamic nature and low abundance of small oligomeric species. In this dissertation, we employed discrete molecular dynamics (DMD) …

Real Time Adaptive Control Of A Pid Via Genetic Algorithm Machine Learning Systems, Cemre Tas

Graduate Theses and Dissertations

The most common control method that is utilized by all industries across the world is the proportional-integrative-derivative controller (PID) due the relatively low cost and complexity of the system. However, there are draw-backs with PIDs, it is not adaptative to a changing system, so it works on nominal systems, and it starts breaking down when a system begins to have a non-linear response. The method chosen to overcome both is the utilization of machine learning with the use of genetic algorithms.

This method allows any PID system to be capable of adapting in real-time, while not adding significant additional cost …