Digital Commons Network^™

Pyridine Nucleotide Redox Potential In Coronary Smooth Muscle Couples Myocardial Blood Flow To Cardiac Metabolism., Marc Matthew Dwenger

Electronic Theses and Dissertations

The maintenance of myocardial oxygen supply during stress is essential for sustaining cardiac health. Enhancement of coronary blood flow upon increases in myocardial oxygen demand (i.e., hyperemia) relies on regulation of voltage-gated K⁺ (Kv) channels by their intracellular β subunits (i.e., Kvβ proteins). Considering that, Kvβ proteins are aldo-keto reductases (AKRs) and regulate Kv channel gating, we tested the hypothesis that elevation of myocardial oxygen demand modifies intracellular NAD(H) in arterial myocytes. Furthermore, we tested whether the resultant change in the redox state of the pyridine nucleotide pool directly regulates coronary Kv1 channel activity. High-resolution imaging mass spectrometry and …

Investigations Of Potential Mechanisms Underlying Spinal Cord Injury-Induced Polyuria., Jason H. Gumbel

Electronic Theses and Dissertations

Spinal cord injury (SCI) results in neurological impairments including motor, sensory, and autonomic dysfunction. These neurological deficits result in a litany of complications apart from muscular paralysis, including bladder, bowel, cardiovascular, and sexual function. SCI-induced polyuria (the overproduction/passage of urine) remains understudied, and therefore mechanisms behind it are largely unknown and require extensive investigation for potential targeted therapies to improve quality of life. The objective of this dissertation was to investigate potential mechanisms of SCI-induced polyuria and explore potential therapies to improve quality of life in the SCI population. Metabolic cages, Western blot, enzyme-linked immunoassay, and immunostaining were first used …

Exploring Service Provider Perspectives On Facilitators And Barriers To Needle Exchange Program Participation By Females Who Inject Drugs., Tammi Alvey Thomas

Electronic Theses and Dissertations

As the opioid epidemic lingers on across the country, many areas have set up harm reduction strategies such as needle exchange programs (NEPs) to combat the long-term consequences of injection drug use (IDU). Males and females face a plethora of health issues associated with injection drug use such as human immunodeficiency virus (HIV) and hepatitis C. While males comprise the largest portion of the injection drug use population, most research is gender neutral, which makes it difficult to discern issues specifically related to females inhibiting our ability to design interventions and procedures targeted to address their needs. Females require varying …

Impact Of Pank1 Deletion On Mitochondrial Acetylation And Cardiac Function During Pressure Overload., Timothy N. Audam

Electronic Theses and Dissertations

Recent studies have associated elevated protein acetylation levels with heart failure in humans. Although mechanisms promoting elevated acetylation levels are not fully known, excess acetyl-CoA may drive enzyme-independent acetylation of cardiac proteins. Accumulation of acetyl-CoA depends on the availability of sufficient CoA, whose production is regulated by pantothenate kinases in the CoA biosynthetic pathway. We show that cardiac proteins are hyperacetylated during heart failure in humans and tested in mice whether limiting CoA abundance would improve ventricular remodeling during pressure overload-induced hypertrophy. We limited cardiac CoA levels by deleting the rate-limiting enzyme in CoA biosynthesis, Pank1 (one of three PANK-encoding …

Assessing The Role Of Arsenic Exposure And Mirna-186 In Skin Tumorigenesis And Chromosomal Instability., Angeliki Lykoudi

Electronic Theses and Dissertations

Chronic arsenic exposure through drinking water is a global health issue, affecting more than 200 million people. Arsenic is a group I human carcinogen and causes chromosomal instability (CIN). Arsenic exposure is the second most cause of skin cancer after UV radiation. MiR-186 is overexpressed in arsenic-induced squamous cell carcinoma relative to premalignant hyperkeratosis. Predicted targets of miR-186 are cell cycle regulators. Thus, we hypothesize that miR-186 overexpression drives malignant transformation of HaCaT cells by induction of CIN. Stable clones of HaCaT transfected with pEP-miR-186 expression vector or empty vector were maintained under puromycin selection were exposed to 0 or …

Characterizing The Role Of Macrophages In Cisplatin-Induced Kidney Injury And Progression To Chronic Kidney Disease., Sophia M. Sears

Electronic Theses and Dissertations

Cisplatin is a commonly used chemotherapeutic for treatment of many solid-organ cancers. Unfortunately, 30% of patients treated with cisplatin develop acute kidney injury (AKI), and even patients who do not develop AKI are at risk for long term declines in kidney function and development of chronic kidney disease (CKD). While traditional rodent toxicity studies have utilized a single, lethal dose of cisplatin, new models of cisplatin-induced kidney injury have revealed that repeated, low doses of cisplatin lead to development of kidney fibrosis. This model can be used to examine AKI-to-CKD transition processes. C57BL/6 mice are one of the most used …

Towards Long Term Colloid Suspension In A Vertically Rotated System., Md Mahmudur Rahman

Electronic Theses and Dissertations

Within a colloidal suspension gravity may compromise the observation of governing physical interactions, especially those that are weak and/or take significant time to develop. Conducting the experiment in a long-term microgravity environment is a viable option to negate gravitational effects, though significant resources are required to do so. While it may not be possible to simulate long-term microgravity terrestrially, particles can resist quick sedimentation in a confined suspension system rotating vertically with appropriate rotation speed. The goal of the investigation is to demonstrate the existence of long-term particle suspension regime for a certain colloidal suspension while characterizing colloidal behavior due …

The Role Of Sphingolipids In Aki And The Progression To Ckd: Potential Therapuetic Targets., Nicholas A. Hoffman

Electronic Theses and Dissertations

Acute Kidney Injury (AKI) is most simply defined as a rapid decline in kidney function over a period of hours to days. There is currently a lack of effective treatment options for patients with AKI, highlighting the need to identify new therapeutic targets. Sphingolipids play a number of roles in different models of AKI, suggesting they could be promising future targets for treating kidney injury. Specifically, sphingosine-1-phosphate (S1P) and its receptors (S1PRs) have been implicated in numerous inflammatory disorders and models of AKI. The purpose of this review is to better characterize the role of S1P receptors in models of …

Social Cognition, Impulsivity, And Emotion Regulation Factors In Aggressive Behavior Among Children With Attention-Deficit/Hyperactivity Disorder., Kelly E. Slaughter

Electronic Theses and Dissertations

Children with Attention-Deficit/Hyperactivity Disorder (ADHD) exhibit greater levels of aggressive behavior than their typically developing peers, often resulting in impairment in social and family functioning. Aggressive behavior is often differentiated into two functions: reactive, or “hot-blooded” and proactive, or “cold-blooded” aggression. Prior research has identified several factors contributing to aggressive behavior within a general population, including emotion dysregulation, negative urgency, social information processing (SIP), and parenting behaviors. A paucity of research has examined these factors within an ADHD population. Thus, the present study aimed to examine social, emotional, behavioral, and cognitive factors associated with aggression among children with ADHD. Specifically, …

In The Balance: Perceptions Of Work-Family Balance For Women In Higher Education., Aubrey Radford Woolley

Electronic Theses and Dissertations

Striking a balance between paid work and family work is hard for many individuals. Previous research has focused on the availability and effectiveness of family friendly policies and demonstrated a need for continued research. I examine work-family balance among women working in higher education. My study asks what are the determinants for work-family balance? I draw on institutional data from the fall 2017 Campus Climate and Diversity Survey which in part focuses on work-family balance. My regression analysis shows that faculty have a lower perception of work-family balance than non-faculty. For both non-faculty and faculty, support from supervisor/chairperson and to …

Study Of The Cell Membrane And The Synthesis Of Chimeric Human Bacterial Phospholipids, Opeyemi O. Tade

Electronic Theses and Dissertations

Phospholipid bilayers are the principal component of the cell membrane. Membranes ensure the maintenance of processes required for cells’ survival by regulating the inflow and outflow of nutrients and other molecules using membrane proteins. However, studying the cell membrane is challenging because of its complexity and small size. In-vitro membrane models made of phospholipids are important tools for studying membranes. In this work, we aim to study the fluidity of phospholipid bilayers of different lipids using general polarization (GP) of the fluorescent probe Laurdan as a measure. We will focus on the relative importance of head groups and fatty acids …

A Method For Identifying Ancient Introgression Between Caballine And Non-Caballine Equids Using Whole Genome High Throughput Data., Kalpani De Silva

Electronic Theses and Dissertations

Introgression is one of the main mechanisms that transfer adapted alleles between species. The advantageous variants will get positively selected and retained in the recipient population while rest of the variants undergo negative selection. When analyzing horse genome, two alleles were found in CXCL16 gene, one associated with susceptibility and one with resistance to developing persistent shedding of the Equine Arteritis Virus. The two alleles differ by 4 non-synonymous variants in exon 1 of the gene. Comparison with 3 non-caballine equids (zebras, asses and hemiones) revealed that one haplotype was almost identical to the haplotype found in non-caballines while the …

Digital Design And Thermomechanical Process Simulation For 3d Printing With Abs And Soyhull Fibers Reinforced Abs Composites., Saleh Khanjar

Electronic Theses and Dissertations

Recent demonstrations with fused filament fabrication (FFF) 3D printing have shown to produce prototypes as well as production components. Additionally, due to the FFF process platforms being low-cost and readily available there has been a high-demand to produce on-demand parts for various applications in automotive, in-space manufacturing and electronic industries. However, current limitations such as limited availability of advanced composites materials, and guidelines for design-for-manufacturing make the process prone to trial-and-error experiments both at the materials development, product design and manufacturing stage. In this work, new thermomechanical process simulations platform, Digimat-AM has been evaluated to address and demonstrate digital design …

Exploring The Contextual Factors And Decision-Making Process Of Risky Sexual Behavior Among Homeless Adults In Louisville, Kentucky., Sarah C. Van Heiden

Electronic Theses and Dissertations

Homelessness is a complex public health issue; individuals who experience homelessness are said to engage in risky sexual behaviors at an increased rate and experience a higher prevalence of sexually transmitted infection (STI). While the sexual behaviors of homeless adolescents are commonly studied, little is known about the sexual behaviors of the growing population of older adults, or how they make decisions to engage in sex. Three aims guided this research: 1) to describe the sexual behaviors and sexual decision-making process of homeless older adults, 2) to examine how homeless older adults evaluate the outcomes associated with engaging in risky …

Materials And Process Design For Ceramic Fused Filament Fabrication (Cf3) Of Hydroxyapatite., Kavish Sudan

Electronic Theses and Dissertations

Ceramic fused filament fabrication (CF3) enables the fabrication of highly customizable ceramic parts at relatively lower costs compared to other AM technologies. Advanced ceramics, having specific or niche applications, call for a high level of accuracy to meet the performance requirements. For achieving the desired level of accuracy in any manufacturing process, it is important to know the effect of involved parameters at different stages of fabrication. CF3 has been around for a while but there has been a severe lack of literature dealing with understanding the effect of process parameters on the final part properties. In this study, Hydroxyapatite …

How Do Cover Crops Change Soil Health In A No-Till System?, Aysha Kirsten Tapp Ross

Electronic Theses and Dissertations

Nutrient levels and aggregation measurements are currently the most accurate means to measure soil health. It has been suggested that bacterial and fungal communities may prove to be a more accurate measure of soil health. In this study soil microbe communities and nutrient levels were compared in rye cover cropped soils to measure for differences between treatments. Effects between the microbial communities and environmental measurements were also measured within those treatments to test for correlations between soil health measures and microbial communities. The plots were put in a biennial corn (Zea mays L.) and soybean (Glycine max …

Computational And Biochemical Characterizations Of Anhydrobiosis-Related Intrinsically Disordered Proteins., Brett R. Janis

Electronic Theses and Dissertations

Anhydrobiosis is the remarkable phenomenon of “life without water”. It is a common technique found in plant seeds, and a rare technique utilized by some animals to temporarily stop the clock of life and enter a stasis for up to several millennia by removing all of their cellular water. If this phenomenon can be replicated, then biological and medical materials could be stored at ambient temperatures for centuries, which would address research challenges as well as enhance the availability of medicine in areas of the world where refrigeration, freezing, and cold-chain infrastructure are not developed or infeasible. Furthermore, modifying crop …

The Association Between Depression And Anxiety With Covid-19 Outcomes., Erica Miller

Electronic Theses and Dissertations

Previous studies have shown that mental disorders affect COVID-19 mortality. This study investigated the effect of depression and/or anxiety on COVID-19 outcomes. Depression/anxiety was defined by actively taking medication and/or diagnosis. The outcomes were ICU admission; ventilation; mortality; and time to mortality. Of 698 hospitalized patients, there were 204 (29%) defined to have either depression or anxiety. There were 109 deaths, and of those, 52 (48%) were diagnosed with depression/anxiety. Multivariable logistic regression and Cox proportional hazards models were used to examine associations. ICU admission and ventilation were not significantly associated with depression/anxiety. Depression/anxiety was associated with mortality (OR: 1.84, …

The Economic Rationality Of Consumption In The Mycenaean Political Economy And Its Role In The Reproduction Of Social Personae: Modeling Prestige Networks., Devin Alexander Stephens

Electronic Theses and Dissertations

This thesis is a theoretical examination of the economic rationality of consumption as it existed within the Mycenaean political economy. Using a modified paradigm of social network analysis, a semiotic approach is used in the study of identity expression and economic stratification present at three Late Helladic cemeteries. In doing so, the claim that exchange strategies which existed outside of palatial redistribution were present in the Late Helladic was substantiated as a similar logic of mortuary stratification which existed during the palatial era was also found to have existed after the shift to the post-palatial era and the collapse of …

Distinguishing Mustela From Neogale (Mustelidae) Through Both A Qualitative And Quantitative Analysis Of Skull And Tooth Morphology, Ronald W. Peery

Electronic Theses and Dissertations

Weasels and mink (Mustela and Neogale) can be difficult to distinguish osteologically due to similarities in morphology, thus suggesting the need for an accurate tool in distinguishing among taxa. This study utilized a combination of character state and stepwise discriminant function (DFA) analyses to examine potential distinguishing features of skull and tooth morphology. Measurements and ratios were collected from all 18 extant musteline species, as well as the extinct Neovison macrodon, Mustela rexroadensis, Mustela meltoni, Mustela gazini, and Mustela jacksoni. Unidentified musteline specimens from the Gray Fossil Site were also included. Results of …

Experiences With Flood And Perceptions Of Flood Risk Among Members Of The Filipino American Community In Virginia Beach, Virginia, Anjelica Pascual Petsch

Institute for the Humanities Theses

The Filipino Americans living in Hampton Roads, Virginia have comprised of almost 2% of the region’s overall population, and 5.3% of the population in Virginia Beach, Virginia (United States Census Bureau, 2019) (Greater Hampton Roads Connects, 2021). Filipino Americans in Hampton Roads, like the rest of the population, are equally vulnerable to experiencing flooding when commuting to and from work or simply traveling around town, but previous research and surveys from the Hampton Roads Region have failed in their ability to capture this cultural diversity within perception of flood risk. In this paper, a qualitative research design was used to …

Impacts Of Environmental And Anthropogenic Stressors On Amphibian Welfare, Diversity, And Distribution In The Upper Missouri River Basin, Kaitlyn Campbell

Dissertations and Theses

Climate change and anthropogenic stressors have contributed to rapid declines among various taxonomic groups; however, amphibian declines have been particularly intense and primarily stemmed from warming temperatures, habitat loss, exposure to contaminants, disease, and their subsequent interactions. Several climate mitigation strategies, like Bioenergy with Carbon Capture and Storage, have been proposed to alleviate the impact of rising temperatures; however, these proposals often fail to recognize and quantify the true impact on fauna, including changes in species distributions. To address this critical gap in knowledge, this research identified current amphibian distributions in the Upper Missouri River Basin and projected distribution changes …

Coevolutionary Methods Enable Robust Design Of Modular Repressors By Reestablishing Intra-Protein Interactions, Xian-Li Jiang, Rey P. Dimas, Clement T.Y. Chan, Faruck Morcos

Biology Faculty Publications and Presentations

enetic sensors with unique combinations of DNA recognition and allosteric response can be created by hybridizing DNA-binding modules (DBMs) and ligand-binding modules (LBMs) from distinct transcriptional repressors. This module swapping approach is limited by incompatibility between DBMs and LBMs from different proteins, due to the loss of critical module-module interactions after hybridization. We determine a design strategy for restoring key interactions between DBMs and LBMs by using a computational model informed by coevolutionary traits in the LacI family. This model predicts the influence of proposed mutations on protein structure and function, quantifying the feasibility of each mutation for rescuing hybrid …

An Intersectionality Framework On The Role Of Student-Teacher Relationships On Student Social Outcomes, Kenji Madison

College of Education and Human Sciences: Dissertations, Theses, and Student Research

This research aimed to build on the great wealth of knowledge on student-teacher relationships, social competence, and peer outcomes while utilizing a different approach integrating race and gender. The view of intersectionality may influence those who join in reading this research to consider race coupled with student gender as a strong influence affecting the formation of a relationship as instrumental as the student-teacher relationship.

In a sample of 10,886 (8489 White, 2397 Black) students from third to fifth grade, the research completed three aims: characterizing the relationship between teacher rated closeness and conflict and students’ social outcomes in fourth and …

Characterization Of The Multifunctional Enzyme Proline Utilization A, Yizi Mao

Department of Biochemistry: Dissertations, Theses, and Student Research

Proline is a unique and important amino acid. Proline is a proteogenic amino acid and its metabolism is involved in many critical cellular functions. Therefore, proline metabolism is tightly regulated, and dysfunction of proline metabolism is related to human diseases. The first step of proline oxidization to ∆¹-pyrroline-5-carboxylic acid (P5C) is catalyzed by proline dehydrogenase (PRODH). P5C is then non-enzymatically hydrolyzed to glutamate-γ-semialdehyde (GSA), which can be further oxidized to glutamate by P5C dehydrogenase (P5CDH/GSALDH). In Gram-negative bacteria, the PRODH and P5CDH enzymes are expressed as one polypeptide called proline utilization A (PutA). In some Gram-negative bacteria an …

The Impact Of Beneficial Organisms In Corn Agroecosystems, Callie Rosalind Braley

Doctor of Plant Health Program: Dissertations and Student Research

Corn is one of the world’s, and Nebraska’s, most important crops. Millions of acres are planted to corn each year in the Cornhusker State. However, each year there are a plethora of arthropod, weed, and microorganism pests that rob farmers of reaching their maximum yield potential. There are many options available to manage these pests in corn agroecosystems, but one option is often underutilized: beneficial organisms. For each pest, there are a variety of natural enemies that can assist in mitigating the damage caused by pests.

Many beneficial organisms exist, and they can be grouped by the type of pest …

Intricacies In Agronomic Management: The Role Of Interdisciplinary Education, Adam M. Striegel

Doctor of Plant Health Program: Dissertations and Student Research

As a science, agronomy is built upon the connection of inter-disciplinary fields of study. Management (M) of various discipline considerations (and their subsequent interactions) can be influenced by and have significant effects on genetic by environment (GxE) expression. This has led to the promotion of GxExM systems. However, optimizing GxExM programs requires extensive, interdisciplinary knowledge. To evaluate interdisciplinary training provided in undergraduate education, 11 four-year universities were selected in the United States that offer baccalaureate degree majors in agronomy or crop science. Surveys of undergraduate programs of study were conducted, with all required coursework separated into general degree components (general …

Examination Of Cajeput Oil (Melaleuca Cajuputi) Phytochemicals As Tools To Manage The Yellow Fever Mosquito (Aedes Aegypti L.), Ellis Johnson

Department of Entomology: Dissertations, Theses, and Student Research

The yellow fever mosquito, Aedes aegypti L., is among the most important insects as it pertains to public health. It vectors several health-endangering pathogens, including yellow fever, dengue fever, chikungunya, and Zika viruses. Insecticides are among the most effective tools used to manage mosquito populations however, their efficacy to manage mosquito populations is being threatened by insecticide resistance. This ongoing threat warrants new chemical strategies to reduce or incapacitate a mosquito population capable of pathogen transmission. Plant essential oils are candidates for identifying novel management tools for disease-vectoring arthropods. Commercially, essential oils have been used for pharmaceuticals, flavoring, fragrances, cosmetics, …

Comparing Machine Learning Techniques With State-Of-The-Art Parametric Prediction Models For Predicting Soybean Traits, Susweta Ray

Department of Statistics: Dissertations, Theses, and Student Research

Soybean is a significant source of protein and oil, and also widely used as animal feed. Thus, developing lines that are superior in terms of yield, protein and oil content is important to feed the ever-growing population. As opposed to the high-cost phenotyping, genotyping is both cost and time efficient for breeders while evaluating new lines in different environments (location-year combinations) can be costly. Several Genomic prediction (GP) methods have been developed to use the marker and environment data effectively to predict the yield or other relevant phenotypic traits of crops. Our study compares a conventional GP method (GBLUP), a …

Accelerated Performance Degradation Of Single-Phase Cold Plates For Direct-To-Chip Liquid Cooled Data Centers, Lochan Sai Reddy Chinthaparthy

Mechanical and Aerospace Engineering Theses - Archive

Expanding demands for cloud-based computing and storage, the Internet of Things, and AI-based applications have escalated thermal loads in high-density data centers which necessitated the utilization of more efficient cooling technologies. Direct-to-chip liquid cooling using cold plates has proven to be one of the most efficient methods to dissipate the high heat fluxes of modern high-power CPUs and GPUs. While the published literature has well-documented research on the thermal aspects of direct liquid cooling, a detailed account of reliability degradation is missing. The present investigation provides an in-depth analysis of the reliability degradation of copper cold plates used in high-power …