Exploration Of Dopaminergic And Serotonergic Pathways Utilizing Pleiotropic Agents, Charles B. Jones Iii

Theses and Dissertations

2-(Benzoyl)piperidines (BPs) are at a crossroads of therapy and abuse. These compounds are a hybrid between the ADHD medication methylphenidate and abused stimulant cathinones. Here we use computational molecular modeling, synthesis, mutagenesis, and epifluorescence microscopy to further improve the understanding of and potential treatments for several neuropsychiatric disorders. Utilizing the BP scaffold and controlling chirality and aryl substitution, these agents were examined at DAT and SERT. From these investigations it has now been established that R isomer BPs are favored for DAT while S isomer BPs are favored for SERT. Aryl-substitution can greatly affect the selectivity of these agents with …

Synthesis Of Lithium Nickel Cobalt Manganese Oxide (Ncm) Cathodes For Lithium-Ion Batteries, Jethrine H. Mugumya

Theses and Dissertations

There are various ways to produce lithium nickel manganese cobalt oxide (NCM) based cathodes for lithium-ion batteries, among them; co-precipitation synthesis carried out in tank-based reactors followed by lithiation is commonly employed because of its cost-effectiveness and scalability. Although it is the preferred synthesis method, it has several issues and challenges. Discussed in this dissertation are some of these issues as well as potential solutions. Physical and chemical properties of the co-precipitation product such as yield, particle size, morphology, and tap density, depend on various reaction parameters, which include pH, chelating agents, metal salt concentrations, and stirring speed. In the …

Effects Of Flooding And Plant Community Arrangement On Freshwater Wetland Greenhouse Gas Emissions And Plant Growth, Walker A. Trainum

Theses and Dissertations

Climate change threatens the status quo of tidal freshwater wetlands by altering their hydrology and species makeup. Increases in water level within freshwater wetlands are well studied, but with the inclusion of saltwater intrusion; while common for some tidal wetlands affected by sea level rise, it is not universal. For wetlands that will experience flooding apart from increases in salinity, adequate study is lacking. For these wetlands, the effect of increasing water level is largely unknown. Thus, the aim of this study was to use an outdoor mesocosm experiment to isolate effects of flooding and communities of differing species makeups …

Muscle-Nerve Signaling And Its Role In Myogenesis, Synaptogenesis, And Regeneration, James T. Redden

Theses and Dissertations

Despite only comprising 0.1% of the myofiber surface area, a healthy motor endplate is densely packed with acetylcholine receptors (AChRs) responsible for mediating activity between the connected motor neuron and skeletal muscle via the neurotransmitter, acetylcholine. Loss of the endplate, known as fragmentation, is caused by car crashes, deep lacerations, and other traumatic injuries to the innervating nerve or direct injuries to the limb muscle(s) with intramuscular denervation as a common comorbidity. In both cases, endplate fragmentation begins within a week of injury proceeding muscle atrophy causing decreased mobility, paralysis, and quality of life. Endplate fragmentation of intact muscle fibers …

Voltage Control Of Interfacial Magnetism For Energy-Efficient Skyrmion-Based Memory And Neuromorphic Computing, Md Mahadi Rajib

Theses and Dissertations

The data generated annually has reached unprecedented levels, necessitating the integration of energy-efficient computing systems to achieve high performance and sustain our society’s computing needs. Specifically, energy-efficient computing, once considered advantageous, has now become essential in managing this exponential data growth. For example, the energy used solely by Google was equivalent to the energy consumed by a country with population >20 million in 2019 and this energy need is increasing exponentially [1]. Therefore, high-performance computing systems with energy-efficient, faster operability, and scalable computing units are necessary to address present and future computing challenges.

Apart from traditionally used conventional von Neumann …

The Many Impacts Of The Covid-19 Pandemic On Latinx College Students’ Mental Health: Exploring The Role Of Sleep, Social Support, And Familismo, Mayra S. Ramos

Theses and Dissertations

College students experienced a multitude of disruptions to their daily life, and changes to their physical (i.e., sleep quality) and mental health (e.g., anxiety and depressive symptoms) because of the COVID-19 pandemic. Though the field has identified the factors that have contributed to negative physical and mental health changes, there remains much to be known about social and cultural protective factors that could buffer the negative role of the COVID-19 pandemic on Latinx college students. The current study contributed to the literature on the mental health outcomes of Latinx college students by identifying a possible mediator and moderators between the …

Mild Traumatic Brain Injury In Yucatan Minipigs: Assessing Changes In Approachability And Mechanical Nociception Following Diffuse Central Fluid Percussion Injury, Mark D. Pavlichenko

Theses and Dissertations

Traumatic brain injury (TBI) is a major healthcare concern affecting millions. Symptoms of TBI include sensory sensitivity and social changes that may persist long-term. Due to similarities in cytoarchitecture, metabolism, and inflammation, higher order minipig models are advantageous for translational TBI research, however, there remains a shortage of information regarding their behavioral and sensory sequelae following injury. Therefore, in this study, we assessed changes in sociability and somatosensation in adult male and female Yucatan minipigs for up to one-week following a sham or central fluid percussion injury (cFPI). Specifically, the voluntary human approach task (VHAT) and the forced human approach …

Neurodevelopmental Trajectories As An Explanatory Mechanism For Adverse Mental Health Outcomes Following Child Maltreatment, Casey Burton Corso

Theses and Dissertations

Affecting one in every seven children in the United States, child maltreatment (CM) is a major public health issue associated with a myriad of adverse outcomes (e.g., alcohol and drug abuse, mental illness, interpersonal violence, sexual risk taking, etc.). While any subtype of CM (e.g., physical abuse, sexual abuse, emotional abuse, and neglect) increases the likelihood of subsequent psychopathology, heterogeneity in psychiatric sequelae of CM is associated with different CM subtypes. Elucidating the underlying mechanisms of this heterogeneity is vital for improving intervention and treatment of CM, and research aimed at accomplishing this is a critical need. One possible explanatory …

Potential Treatments For Epileptiform Activity In Microgyral Cortex, Eliot R. Niessen

Theses and Dissertations

In this study, the effects of several drug treatments on epileptiform activity in the freeze lesion (FL) mouse model of epilepsy have been evaluated and compared. The FL model replicates the histopathology and epileptiform activity that occurs in humans with the developmental cortical malformation of polymicrogyria (PMG). While Gabapentin is already used in a clinical setting to treat seizures, there are other alternatives that have not been fully tested. Rapamycin, for instance, has been shown to reduce seizures in other models of epilepsy. It is an inhibitor of the mammalian target of rapamycin (mTOR) pathway, which regulates the function of …

Mathematical Modeling Of Phage-Bacteria Population Dynamics, John Lawrence D. Palacios

Theses and Dissertations

Bacteriophages are viruses that infect and replicate within bacteria. Lytic phages cause the bacterial cell to burst, killing the bacteria. These types of phages can be used to treat patients with antibiotic-resistant bacterial infections. As a step in developing successful treatment protocols, we aim to understand the population dynamics of phages and bacteria using an in vitro model. We model the dynamics using the Campbell model, which consists of a delay differential equation (DDE), as a base model. We extended the model by including the emergence of phage resistance. We then compared the DDE model with a parallel ordinary differential …

Hybrid Design Approaches For Reconfigurable Em Structures, Jonathan D. Lundquist

Theses and Dissertations

The modern world is replete with reasons for employing reconfigurable electromagnetic (EM) structures, but some of the most pressing needs require advancements in power consumption, speed, and footprint [1]. Next generation air defense (NGAD) fighters could benefit from new electronic warfare (EW) countermeasures [2], as well as adaptive stealth technology [3], while doctors could benefit from reconfigurable microwave ablation antennas that can modify radiation pattern and input impedance to match changes in tissue during ablation and account for variations in tumor shapes [4]. The future of antennas, filters, and lenses is reconfigurable as real-world matters of life and death may …

Machine Learning Assisted Optimization For Calculation And Automated Tuning Of Antennas, Lauren Linkous

Theses and Dissertations

The Antenna Calculation and Autotuning Tool (AntennaCAT) software suite represents a significant advancement in the field of antenna design by automating the entire design, CAD, simulation, and optimization process compatible with several EM simulation software suites. It is the first comprehensive implementation of machine learning in this context. In particular, this work includes the capability to create and export structured datasets from the aforementioned EM software for iterative improvement and includes an expandable selection of optimizers.

T Cell Polarization Regulates The Inflammatory Response And Tissue Regeneration At The Peri-Implant Interface, Derek Avery

Theses and Dissertations

Unresolved healing and localized chronic inflammation are common occurrences after biomaterial implantation, resulting in unfavorable clinical outcomes such as implant failure or fibrous encapsulation. T cells are adaptive immune cells found in lymph nodes, thymus, spleen, bone marrow, and around biomaterials, significantly impacting the degree of inflammation and wound healing. T cells are vital for inflammatory cytokine production and modulation of innate immune cells, including neutrophils and macrophages. T cells can be differentiated into two primary subsets, CD4⁺ and CD8⁺ T cells, playing distinctive roles in various pathologies and disease states. While T cells have been characterized well …

Using Asset-Based Community Development To Increase Student Engagement And Improve Student Experience In Schools, Jacqueline Hopkins

Theses and Dissertations

The following is a dissertation in the three-paper dissertation format. The first section will give background information on the issue of alienation in schools and how asset-based community development (ABCD) could be an effective tool for educators to combat alienation and disengagement, especially with students with marginalized identities. This first section will also show the significance of the three papers as a whole and how they connect to one another. The first paper is the conceptual literature review, the second paper is an empirical study of the ABCD model in schools, and the dissertation will end with a practitioner's article …

How Ebony Transcends In The Ivory Tower: Unveiling Transformational Black Women Forging Leadership Paths In Historically White Institutions, Lauren N. Jackson

Theses and Dissertations

Considerable literature has amplified the perceived challenges and deficits of Black women as they advance in their careers within historically white institutions (HWI). As a result, there is a notable absence of anti-deficit explorations of the inherent abilities and strengths that contribute to Black women’s professional mobility. Grounded in anti-deficit achievement framework and Black feminist leadership, this study aimed to illuminate the assets and factors that influence the professional ascension of seven, current/former senior-level Black women in a HWI within the Southeastern region of the U.S. By adopting a qualitative, phenomenological framework, this study provides in-depth insights into the participants’ …

Effect Of Annealing On Photoluminescence From Defects In Gan, Oleksandr Andrieiev

Theses and Dissertations

Annealing is a critical process in modern GaN technology, essential for achieving p-type conductivity by activating the Mg_Ga acceptor, as first demonstrated by Shuji Nakamura in the early 1990s. Despite the omnipresence of hydrogen as an impurity in GaN crystals, the precise mechanisms governing hydrogen diffusion and acceptor passivation remain only partially understood. The presented research investigates the effects of annealing-induced activation and hydrogen passivation on C and Be acceptors in GaN grown by MOCVD, HVPE, and MBE methods. We explored these effects by using several annealing techniques, gas compositions, and thermal regimes. A transient behavior between the C …

Genetic And Transcriptomic Investigations Of Progressive Ethanol Consumption In The Diversity Outbred Mouse, Zachary Tatom

Theses and Dissertations

As a complex genetic disorder, alcohol use disorder (AUD) is thought to be influenced by many genes each contributing only a small effect to the overall disease liability. Dozens of genes have been implicated as potentially affecting risk for AUD and alcohol consumption. However, understanding the full genetic architecture of AUD – what genes are involved, to what extent, and how these genes are regulated – remains a challenging step in identifying novel treatments. Gene expression studies in humans have attempted to augment GWAS of alcohol consumption but are often confounded by environmental factors; the difficulty of collecting tissue from …

Bridging The Gap In Epsilon-Near-Zero Nonlinear Materials, Adam R. Ball

Theses and Dissertations

Studying how light and matter interact has been of interest to humans for thousands of years. From the invention of the first mirror, burning ants with a magnifying glass, to optical fiber communication, light has been central to mankind. Researchers have sought to take this to the extreme with nonlinear optics where intense laser light interacts with materials. The study of this thesis is to understand a new generation of materials that has come to light. Epsilon-near-zero (ENZ) materials have shown promise for ultrafast light manipulation in tandem with modern day CMOS compatible electronics. Here, I seek to bridge the …

Openfoam Computational Fluid Dynamic Modeling Of Plasma Expansion Into Vacuum, Robert B. Padgett

Theses and Dissertations

Nuclear weapons, and their effects, have been heavily studied with decades of data and information to create simulations and quantify the risks of their use. However, in the modern day, nuclear strikes pose new risks to precision electronics, power systems, and vital infrastructure. As such, simulations of nuclear weapon use are required due to nuclear weapon testing being prohibited. These simulations can incorporate testing practices, such as laboratory lasers, and computer simulation technology, such as OpenFOAM Computational Fluid Dynamics (CFD). The use of OpenFOAM CFD allows testing in an area that has never been tested with nuclear weapons before, specifically …

Multi-Magnetic Material Transcranial Magnetic Stimulation Coils Development And Electric Field Measurement & Modeling Using Machine Learning, Mohannad Tashli

Theses and Dissertations

Transcranial Magnetic Stimulation (TMS) is a safe, effective, and non-invasive therapy for treating several psychiatric and neurological disorders. TMS is Food and Drug Administration (FDA) approved treatment and is commonly applied to patients who do not respond to medications for the treatment of clinical depression, smoking cessation, obsessive-compulsive disorder and migraine. Recently, there has been an increase in the development of electromagnetic neuromodulation techniques targeted at enhancing the effectiveness of TMS devices for the treatment of mental diseases. In TMS stimulation, focality is an important factor which determines the specificity of the pulses induced in different brain tissues. The electromagnetic …

Evaluation Of Alternative Methods For Dna Recovery Of Compromised Skeletal Remains, Ciara N. Rhodes

Theses and Dissertations

Skeletal remains frequently serve as the sole source of genetic material available for developing a profile in cases concerning unidentified human remains or mass casualties. Nevertheless, as unidentified skeletal remains age and are exposed to uncontrolled environmental conditions, the success rates of conventional methods of bone analysis diminish significantly. The physical and mechanical processing of skeletal remains into fine powder for DNA isolation and downstream analysis can substantially impact the quality and quantity of recoverable genetic information. This concern may be exacerbated when dealing with degraded forensic skeletal remains. Few studies have explored whether pulverization of bone samples contributes to …

Title: I: L1-Norm Matrix Completion For Recommender Systems Ii: Conjecturing-Based Classification, Fatemeh Valizadeh Gamchi

Theses and Dissertations

Recommendation systems are essential for providing personalized user experiences, but their performance can be affected by outliers especially in traditional collaborative filtering methods that use the L2-norm. To address this challenge, we developed two new algorithms, SharpEl1rs and SharpEl1rs-Impute, based on the L1-norm to improve resistance against extreme values and effectively handle missing data. Our experimental setting was designed to compare these proposed methods with existing techniques. Then our algorithms are applied to real datasets to assess their performance, with findings indicating that our proposed models offer improved accuracy in some cases and solid performance in others for industrial-scale recommendation …

Fluid Flow And Thermal Performance Investigation Of Twisted Elliptical Tubes For Use In High Prandtl Number Systems, Connor F. Donlan

Theses and Dissertations

The development of clean energy systems is paramount to reducing mankind's climate impact. These clean energy systems include solar, wind, and nuclear power where nuclear power shows a reduced lifetime carbon dioxide footprint per kilowatt hour compared to other sources [102]. Advanced nuclear reactors, fusion energy systems, and concentrated solar power designers are looking at using molten salt heat transfer fluids and improved heat exchanger design to increase power production and efficiency of clean energy systems. The improving heat transfer within the main heat transfer components within advanced nuclear reactors will enable increased efficiencies and power production.

Heat transfer improvements …

Longitudinal Analysis Of Maternal Depression, Physical Work Demand, And Working Hours Before, During, And After Pregnancy On Offspring Blood Pressure Trajectories, Medhin Tsegaye Haile

Theses and Dissertations

Overall Abstract

Background: Pediatric high blood pressure (BP) is a growing global concern, with 1 in 7 adolescents in the U.S. experiencing elevated BP or hypertension. Maternal lifestyle factors, including depressive symptoms, physically demanding work, and work hours during pregnancy, may influence offspring BP trajectories. However, prior studies often focus on single time points or specific age groups, limiting understanding of long-term effects. This study investigates the associations between maternal depressive symptoms, physically demanding work-related factors, and work hours before, during, and after pregnancy with offspring systolic blood pressure (SBP) trajectories from early childhood to adolescence.

Methods: We utilized …

Cellular Metabolism Is A Viable Therapeutic Target For Radiation-Induced Pulmonary Fibrosis, Josly Pierre-Louis Odoom

Theses and Dissertations

Herein, we provide evidence for cellular metabolic reprogramming as a driver of radiation-induced pulmonary fibrosis (RIPF). We are the first to identify a distinct metabolic signature for RIPF in a cohort of patients with radiographic sequela. We also used a RIPF mouse model to detect the metabolic pathways that enrich during pathogenesis. Our previous work highlighted the importance of lactate, a derivative of the glycolysis end-product pyruvate. Consequently, we took a special interest in the effects of radiation on the glycolysis pathway. We learned that radiation accelerates and reprograms glycolysis to an anabolic state in a pyruvate kinase M2 (PKM2)-dependent …

Long-Wave Modeling Of Viscous Film Dynamics Inside A Tube With Time-Dependent Radius, Robert E. Hicks

Theses and Dissertations

Lung fluid dynamics is a well studied topic and relevant in the field of research surrounding patients with Chronic Obstructive Pulmonary Disease (COPD) and cystic fibrosis. However, the literature on the mathematical description of the net pulmonary fluid transport in the case of constricting and expanding airways is scarce. In this paper we aim to address how breathing contributes to airways clearance in patients with pulmonary diseases such as COPD and CF in which cilia do not function properly. We begin with the flow of a fluid-filled tube with rigid walls of fixed radius and the effects of gravity being …

Examining Parent Behavior And Adolescent Outcomes In A Pediatric Obesity Intervention, Madison W. Weinstock

Theses and Dissertations

Pediatric obesity is a major public health concern that affects over 14.4 million children and adolescents in the United States. Multiple short- and long-term health complications are associated with obesity. Therefore, effective treatment methods are needed in order to ameliorate the effects of said complications, particularly among adolescents. This dissertation investigated potential associations between parent eating behaviors and the outcomes of adolescents enrolled in a pediatric weight loss trial (TEENS+; PI: Bean, R21HD084930). The TEENS+ intervention offered a comprehensive behavioral weight intervention for parent-adolescent dyads. Given the well-established importance of parents in the development of an adolescent’s health behavior, this …

Life After Discharge: Predicting Longitudinal Trajectories Of Community Integration And Global Functioning In Black Individual With Traumatic Brain Injury, Chimdindu Ohayagha

Theses and Dissertations

The onset of traumatic brain injury (TBI) begins a chronic health pathway that contributes to various impairments and comorbidities across the lifespan. Common consequences of TBI include mental health issues, cognitive impairments, and reduced functional independence, all of which impact how an individual integrates into their community. Community integration is a primary goal for rehabilitation after TBI. Studies show that racially/ethnically minoritized individuals have a higher incidence of TBI, higher rates of mortality, and report poorer functional and community integration outcomes. Limited studies have explored longitudinal outcomes of community integration in a Black-only sample of individuals with TBI. Additionally, no …

Functional Monitoring For Run-Time Assurance Of A Real-Time Cyber Physical System, Matthew W. Gelber

Theses and Dissertations

As cyber-physical systems (CPS) become more integrated into everyday life, the security of these systems must also be considered during their development due to their ever-increasing importance. With the growth of physical components in the system, more autonomous control requirements, and increased dependence on proper functionality, verifying system safety and correct operation becomes increasingly difficult. CPS have become more complex through the combination of additional hardware and the resulting interconnected software in many layers, each requiring unique security solutions. One example of such a safety-critical CPS embedded system is the Flight Control System (FCS) of an Unmanned Aerial System (UAS). …

Essays On The Impacts Of Macra 2015 And Market Dynamics On Quality, Billing, And Fraud In The U.S. Healthcare System, Mahmoud Manouchehri Amoli

Theses and Dissertations

This thesis presents a comprehensive examination of the impacts of the Medicare Access and CHIP Reauthorization Act of 2015 (MACRA) and market dynamics on the quality, billing practices, and incidence of fraud within the U.S. healthcare system. It is a compilation of three essays that each delves into a specific facet of the healthcare landscape altered by MACRA's introduction and the evolving market conditions.

Chapter 2 analyzes how MACRA has transformed Medicare Part B physicians' practices by introducing the Merit-Based Incentive Payment System (MIPS) and Advanced Alternative Payment Models (APMs). The study provides empirical evidence on the shift in billing …