Digital Commons Network^™

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 …

Coal Fly Ash Beneficiation For Reuse And Removal Of Boron, Cadmium, Chromium, Copper, And Selenium In Wastewater Treatment., Joseph E. Cahill

Electronic Theses and Dissertations

New regulations on coal-fired power plants make previously used wastewater treatment methods aimed to remove heavy metals obsolete. Therefore, there has been increased interest and investment into new technologies to treat coal-fired power plants effluent in the past few years. Traditionally, heavy metal removal technologies have been broken into three categories: physical, chemical or biological. However, with new regulations, each category by itself does not offer an ideal solution to removing acceptable concentrations of heavy metals found in the effluents at the coal-fired power plants. Here we report a novel proof-of-concept utilizing adsorption through ion-exchange/co-precipitation - chemical and physical - …

Scalable Synthesis Of Alumina Nanowires By Wet Chemical Method., Luis N Moreno

Electronic Theses and Dissertations

To satisfy an increasing demand for large-scale processes for producing alumina nanomaterials, a wet chemical method was evaluated. A potassium salt precursor was combined with aluminum to produce alumina – based nanowires. Compared with current methods such as thermal oxidation, sol-gel, and laser ablation, this method is highly scalable due to relatively low energy requirements and the ability to carry out the primary reaction under ambient conditions. The nanowire samples were evaluated using SEM, XRD, BET, and TEM to confirm morphology, phases present, and surface area. A porous nanowire structure was confirmed which has a BET surface area of 324.6 …

Update Of Multicellular Data Standard To Match Physicell "Compact" Output., Reid A Honeycutt

Electronic Theses and Dissertations

In the field of multicellular biology, it is currently very difficult for researchers to share digital data, due to a lack of standards for said data. Each laboratory will collect data from a particular project, which will describe only the features relevant to their research, and then present that data using written descriptions, charts, graphs, and images. This makes it difficult for the data produced by these studies be leveraged in other research efforts by scientists studying similar phenomena. An open-source, universal standard that attempts to meet this need is the MultiCellular Data Standard (MultiCellDS). MultiCellDS is described as a …

Design Of A 300cm2 Pemfc Stack With Force And Cfd Simulation To Optimize Flow Channels, Gasket Design, And Clamping Forces., Robert M. Ench

Electronic Theses and Dissertations

Proton exchange membrane fuel cells are important to the future of green energy as hydrogen can be made with green technologies and store energy for later use. Fuel cells can efficiently convert the hydrogen to electricity as needed. This study uses Solidworks simulation to make design improvements to the fuel cell before the prototype build stage of testing; this saves money and time by reducing the prototype builds needed.

In this study, a multi-channel serpentine design with two outlets versus a single outlet is evaluated using CFD to investigate pressure drop. Lower pressure drops are desirable as less energy input …

Solvent Engineering Of Molybdenum Disulfide Electrocatalyst For Hydrogen Evolution., Robert Carl Spalding

Electronic Theses and Dissertations

Energy is at an exponentially growing demand, and to keep up with these demands new technologies for renewable energy have received increased attention. Hydrogen plays a vital role in water electrolysis and fuel cells, as the hydrogen evolution reaction (HER) is the main step water splitting process. Most of the current electrocatalysts for HER are dominated by platinum and other precious metals due to their low over-potential and small Tafel slope, however, they are extremely costly. For this reason, cost-effective non-precious metal catalysts must be developed. Transition metal dichalcogenides, such as molybdenum disulfide (MoS2), are abundant and have recently shown …

Computational Modeling Of 3d-Printed Lactobacillus-Antibiotic Scaffolds For Bacterial Vaginosis., Veeresh P. Rai

Electronic Theses and Dissertations

The standard treatment for bacterial vaginosis (BV) is currently antibiotics, such as metronidazole, clindamycin, or tinidazole. These antibiotics are highly effective in getting rid of bacteria in the female reproductive tract (FRT); however, there are some bacteria that provide benefits to the FRT which also get expunged. While there are many strains of bacteria that play a beneficial role in the FRT, lactobacilli are among the most important. These bacteria are responsible for maintaining a healthy environment in the FRT via pH regulation by lactic acid metabolism. Antibiotics eliminate all bacteria from an environment, including lactobacilli, and as a result, …

Trained Immunity Enhances The Immune Response And Maintains Microbiome Diversity In Aging And Sepsis, P. Spencer Gill

Electronic Theses and Dissertations

The global population is rapidly aging. It is estimated that over the next thirty years, the number of individuals >60 years of age will increase by over a billion, and the number of individuals over age 80 may increase by 300 million. As humans age, our immune system becomes progressively weaker through a process called immune senescence. This age-related decrease in immune function increases susceptibility to infection and chronic diseases. Sepsis is a leading cause of death worldwide. Over the past two decades, there has been an increased incidence of sepsis which is due, in part, to our aging population …

Correctional Career Pathways: A Jail Reentry Program Evaluation, Grace Gass

Electronic Theses and Dissertations

There are numerous types of reentry programs available to inmates to help avoid the cycle of recidivism. There is little research on the impacts of reentry programs in jail populations. This current study sought to provide more research in this area by evaluating a local jail reentry program’s effect on recidivism. A quasi-experimental design was used to estimate the program’s effectiveness by comparing the recidivism statistics of inmates that have participated in the reentry program to a control group of inmates that did not. Inmates in the control group were matched according to their gender, age, race, and current offense …

Lipidomic Analysis Of Various Developmental Stages Of Physcomitrium Patens, Deepshila Gautam

Electronic Theses and Dissertations

Lipids maintain fluidity of the cell membrane during the lifetime of all organisms. The moss Physcomitrium patens, an early land plant, enters reproductive phase under cold (15°C) conditions relative to its gametophytes (22°C). Thus, we hypothesized that their lipid content and composition would be distinct. Using ESI-MS/MS, we showed that the content and acyl composition of 11 lipid classes varied during development. Galactolipids were abundant in gametophytes but insignificant in sporophytes; among phospholipids, phosphatidylcholine was predominant in both phases. Although, sporophytes contained around five-fold less lipids than the gametophyte, their phosphatidic acid content, which accumulates during stress, was 18-fold …

Computational Analysis Of The Spin Trapping Properties Of Lipoic Acid And Dihydrolipoic Acid, Matthew Bonfield

Electronic Theses and Dissertations

While the spin trapping properties of thiols have been investigated through EPR analysis and kinetics studies, few groups have studied these properties using strictly computational methods. In particular, α-lipoic acid (ALA) and its reduced form, dihydrolipoic acid (DHLA), one of the strongest endogenously produced antioxidants, show potential for being effective, naturally occurring spin traps for the trapping of reactive oxygen species. This research covers electronic structure calculations of ALA, DHLA, and their corresponding hydroxyl radical spin adducts, performed at the cc-pVDZ/B3LYP/DFT level of theory. The effects on DHLA introduced by other radicals such as ·OOH, ·OCH₃, …

Genital Chlamydia Infection Is Influenced By The Female Sex Hormones Estrogen And Progesterone In Vivo, Amy Gail Gravitte

Electronic Theses and Dissertations

Chlamydia is the most common bacterial sexually transmitted infection in the United States and worldwide. It often goes unnoticed due to lack of symptoms and left untreated it can ascend the female genital tract to cause sequelae like pelvic inflammatory disease and irreversible tubal infertility. In reproductive-aged women, female sex hormones estrogen (E2) and progesterone (P4) concentrations fluctuate during the menstrual cycle and are influenced by hormonal contraceptives and hormone replacement therapy. E2 and P4 influence genital Chlamydia infection in women and mice, but these multifactorial interactions are not entirely mapped out. The complex interplay of E2 and P4 with …

Stress And Anxiety Experience Of Dental Hygiene Students, Kristen Ford

Electronic Theses and Dissertations

The ETSU dental hygiene program is very competitive and rigorous for those admitted. Student dental hygienists may experience higher levels of anxiety and more stressors while completing their course work and clinical hours than they have previously experienced in general education and prerequisite courses. These increased number of stressors and higher levels of anxiety may have negative impacts on students’ academic performance and success in clinical learning environments. A better understanding of the actual need for a stress reduction and anxiety management curriculum will facilitate creating and implementing this type of curriculum. A total of 44 current ETSU dental hygiene …

A Causal Comparative Study Of Stem Persistence Between Supported And Non-Supported Stem Interested Students, Elizabeth Bernardi

Electronic Theses and Dissertations

Many students who enter a STEM track in college move out of that track before graduation (National Science Foundation, 2018). The purpose of this study was to assess whether there was a difference in STEM-related major persistence for population proportions of students actively involved in the Science Scholars program and those who were STEM-interested but not program participants. This program oriented students to the STEM program, facilitated engagement with peers and faculty, exposed students to research opportunities, and filled in potential learning gaps (Gibson et al., 2019).

The questions guiding the current research included:

Q1. Was there a statistically significant …

Preparation And Study Of Bacterial Membrane Models, Enoch Asimbisa

Electronic Theses and Dissertations

Fuel molecules are organic solvents that have disruptive effects on the bacterial membrane. This is a significant barrier in biofuel production, as it limits the fuel concentration that can be achieved through fermentation. One potential way of overcoming this barrier is to identify lipid compositions that can better withstand solvent stress, for which it is important to understand how organic solvents disrupt the membrane. Use of biophysical characterization techniques to quantify physical properties like fluidity and thickness will enable us to understand the mechanism by which solvents disrupt membranes. Native membranes are very complex, and we sought to develop in-vitro …

Synthesis Of Phosphatidylethanolamine Lipids For Model Studies Of The Cell Membrane, John Hayford G. Teye-Kau

Electronic Theses and Dissertations

Concerns about global warming have resulted in a surge of research into alternatives to fossil fuels. In recent years, biofuels have gained traction due to their low environmental impact. Biofuel production most commonly employs microorganisms to convert biomass to fuel for industrial and transportation applications. Compounds made in biofuel production, however, are toxic to cell membranes and disrupt their integrity, harming the microorganisms and limiting biofuel yield. A key to overcoming this challenge is understanding how fuels interact with microorganisms’ cell membranes, which perform a host of functions, including transport, cell recognition, transduction, and movement. Phospholipids are the cell membrane’s …

Student Collaboration: Early Childhood Teachers' Roles And Perspectives, Kimberly Ballantyne

Electronic Theses and Dissertations

Early childhood environments can offer valuable opportunities for student collaboration. Social interactions allow students to practice listening to each other and learn how to work together. This study focused on the roles and perspectives of early childhood educators related to student collaboration in the classroom. Six educators from one elementary school in New Hampshire participated in two focus group discussions, the first of which included a presentation on student collaboration with first graders. Participants also completed four concept maps highlighting their perspectives about student collaboration and one written reflection comparing their perspectives before and after engaging in the focus group …

Synthesis Of Phytosulfokine Analogs As Probes For Studying Plant Signaling And Molecular Trafficking, Thomas Ntim

Electronic Theses and Dissertations

Plants are exposed to a wide range of biotic and abiotic stresses that hinder their growth and reduce crop productivity. In their adaptive response, plants use signaling molecules that are trafficked throughout the plant. This research focuses on the chemical synthesis and assessment of analogs of the plant signal phytosulfokine (PSK, a sulfated pentapeptide), its delivery to plants and its observation using a fiber-optic fluorescence microscope. PSK regulates growth, cell expansion, heat tolerance, and tissue longevity. Analogs of PSK were synthesized using solid-phase peptide synthesis. Pure PSK and TAMRA-labeled PSK were delivered into the wild-type Arabidopsis thaliana Col-0 and a …