Digital Commons Network^™

Essays On The Market For Higher Education, Samuel Lawrence Rhoads Glick

Theses and Dissertations--Economics

This dissertation studies the market for higher education and impacts of higher education policy on the market. In the first chapter, I estimate the short-run elasticity of supply of higher education using the rollout of state merit grant programs as plausibly exogenous variation in student demand for in-state higher education. I find that public and private not-for-profit four-year institutions have elastic supply responses to these programs. Public institutions have an estimated elasticity of 2.1 and private institutions have an estimated elasticity of 1.34. I estimate the causal effects of marginally qualifying for and receiving the federal Pell Grant and the …

Essays On The Economics Of Entrepreneurship, Nicholas Graff

Theses and Dissertations--Economics

This dissertation consists of three chapters related to the economics of entrepreneurship. The second chapter focuses on the business performance of necessity entrepreneurs, specifically focusing on job creation and earnings. The third chapter investigates the large and persistent earnings differences between self-employed men and women, finding women earn less in self-employment because of different choices of industry, number of hours worked, and differences in business capital. The fourth chapter investigates whether the black-white self-employment gap explains the black-white wealth gap.

Evaluating The Early Impacts Of The Snap Online Purchasing Pilot, Kyle Jones

Theses and Dissertations--Economics

This dissertation consists of three chapters that evaluate how a change in the redemption of Supplemental Nutrition Assistance Program benefits impacted grocery purchasing behavior and food consumption to provide some of the first estimates of the impacts from the pilot. The SNAP Online Purchasing Pilot (OPP) allowed recipients to use their benefits online for participating retailers which was initially planned for 8 participating pilot states with a few participating retailers but massively expanded during the COVID-19 pandemic. The first two chapters evaluate how the SNAP OPP impacts grocery purchasing behavior with the first chapter evaluating before the COVID-19 pandemic and …

Essays On Impacts Of Natural Disasters, Fang-Yu Yeh

Theses and Dissertations--Economics

This dissertation consists of three chapters that study how natural disasters affect households and individuals. The first chapter examines how Kentucky’s housing market responds to changes in flood risk information. The second chapter looks at disproportionate drinking water non-compliance post-disaster. The third chapter studies the effect of flooding events and the national school meals program in Kentucky on education outcomes.

The first chapter examines Kentucky’s housing market response to changes in the Federal Emergency Management Agency’s (FEMA) flood maps and how the responses differ depending on whether an area has been flooded recently. I use Zillow’s ZTRAX property transaction data …

Modulating The Mtor Pathway Using Inducible Retrogradely Transported Aavs As A Novel Approach To Improve Motor Recovery In Spinal Cord Injury, Christopher Bosse-Joseph

Theses and Dissertations--Medical Sciences

Spinal cord injury poses multiple regeneration barriers, including neuronal-intrinsic and extrinsic factors. Overcoming these barriers has stood as a longstanding challenge in neuroscience. A well-studied mechanism to promote spinal cord regeneration and locomotor recovery is activating the PI3K/mTOR pathway by knocking out phosphatase and tensin homolog protein (PTEN). PTEN knockout (PTEN-KO) studies have traditionally used adeno-associated virus (AAV) viral vectors to improve functional recovery. The use of traditional AAV serotypes to induce PTEN-KO has shown promise to improve functional recovery in rodent models; however, these approaches show significant limitations for translational utility. Firstly, the use of traditional AAV serotypes to …

The Role Of Intracellular Growth During The Systemic Spread Of Listeria Monocytogenes, Jamila S. Tucker

Theses and Dissertations--Microbiology, Immunology, and Molecular Genetics

Listeria monocytogenes is a facultative intracellular pathogen transmitted through the consumption of contaminated food products. Typically, infections range from mild, self-limiting gastroenteritis to life-threatening systemic infections; however, the events that occur in the gut to allow for this spread are unclear.

The focus of my thesis aims to determine how L. monocytogenes escape the mesenteric lymph nodes (MLN), the final barrier to systemic spread for both commensal and pathogenic bacteria in the gut. I have shown that intracellular replication of L. monocytogenes in an as-yet-unidentified cell type is essential for the colonization and dissemination of the bacteria from the MLN. …

Effects Of Pancreatic Amylin On The Peripheral And Cns Immune Response In A Model Of Type-2 Diabetic Brain Injury, Edric Da'shon Winford

Theses and Dissertations--Neuroscience

Type-2 diabetes (T2D) is a metabolic disorder that increases the risk for cerebrovascular disease and dementia and is associated with the progression of Alzheimer's Disease; however, the mechanisms responsible for T2D-associated dementia are still poorly understood. T2D leads to alterations of the innate and adaptive immune response that contribute to its progression, but how these cells contribute to cognitive decline during T2D is unknown. As there are no approved therapeutics for T2D that modulate the immune response, it is important that we investigate how peripheral immune cells contribute to cognitive decline during T2D. Amylin is an amyloidogenic hormone synthesized and …

The Effect Of Estrogen And A Mitochondrial Uncoupling Prodrug On Traumatic Brain Injury-Induced Dysfunction In Mice., Olivia J. Kalimon

Theses and Dissertations--Neuroscience

A large percent of both clinical and pre-clinical traumatic brain injury (TBI) studies report better outcomes females after severe injury compared to males. Mitochondrial dysfunction is a well-characterized driver of secondary injury and an attractive neurotherapeutic target; though, there is limited research available on mitochondrial dysfunction in females. However, a few studies have shown total mitochondria from the cortex of females appear protected from TBI-induced bioenergetic dysfunction. These results were replicated in these studies so further characterization was performed. Additionally, protein expression of some oxidative phosphorylation (OXPHOS) complexes were elevated in the uninjured cortex of females relative to uninjured males, …

Caenorhabditis Elegans Rapgef Promotes Synaptic Development Through A Small G Protein Signaling Cascade, Reagan Em Lamb

Theses and Dissertations--Neuroscience

Synaptic dysfunction is a major contributor toward the development of many neurological disorders. For proper development, synapses require a series of signaling pathways to guide them, but not all the mechanisms underlying these processes are understood. Here, we used the neuromuscular junction of Caenorhabditis elegans as a model circuitry for examining underlying pathways that mediate proper development of synapses. We hypothesized that the C. elegans RapGEF2 and RapGEF6 orthologue, PXF-1, contributed toward development of cholinergic synapses at the neuromuscular junction. Using behavioral assays and fluorescence microscopy, we found that pxf-1 mutant animals had decreased neuromuscular junction function and decreased synaptic …

Contributions Of The Replication Initiator Protein Dnaa To Physiology And Virulence Of The Lyme Disease Spirochete, Andrew Krusenstjerna

Theses and Dissertations--Microbiology, Immunology, and Molecular Genetics

Borrelia burgdorferi, the etiological agent of Lyme disease, is the most prevalent vector-borne disease in the United States. The spirochetal population is naturally maintained by consistently cycling between Ixodid ticks and small vertebrates. To survive within these diverse niches, B. burgdorferi has evolved a unique physiology and regulatory network to sense and respond to environmental fluxes. Replication is a hallmark of the Lyme spirochete’s enzootic life cycle, specifically at the nymphal tick-to-vertebrate interface. The mechanisms and regulatory schema for the basic cellular processes in B. burgdorferi, or indeed any member of the phylum spirochaetota, are largely unknown. The central hypothesis …

Enlarged Perivascular Spaces Are A Clinically Relevant Neuroimaging Biomarker Of Cerebral Small Vessel Disease, Timothy Justin Libecap

Theses and Dissertations--Neuroscience

Vascular contributions to cognitive impairment and dementia (VCID) represents the intersection between cerebrovascular disease and cognitive decline. Cerebral small vessel disease (cSVD) is an important risk factor that may precede the onset of VCID by years. cSVD is characterized by in-vivo neuroimaging biomarkers including enlarged perivascular spaces (ePVS). PVS are the site of interchange between interstitial fluid (ISF) and cerebrospinal fluid (CSF) which is believed to play a role in the removal of brain waste. Reduced clearance may lead to enlargement of the PVS and subsequent accumulation of toxic solutes characteristic of neurodegeneration. Given the presence of ePVS in brain …

The Role Of Dystrophic Microglia In Aging And Disease, Ryan K. Shahidehpour

Theses and Dissertations--Neuroscience

Microglia are the primary immune cells of the central nervous system and are crucial in maintaining homeostasis and defense from disease and injury in the brain. Recent genome-wide association studies (GWAS) have also highlighted microglia as a central player in Alzheimer’s disease (AD). However, the mechanisms of microglia’s influence are poorly understood. Traditionally, microglial subtypes characterized physiologically as “reactive” or “activated” have been linked with disease and injury in the brain. However, morphologically, a recently described microglia category known as “dystrophic,” characterized structurally by fragmented processes and cytoplasmic decay is believed to be more strongly associated with aging and neurodegeneration. …

Characterizing Age-Associated Cd19+ B Cells After Stroke In Aged Male And Female Mice Reveals Sex-Dependent Functional Recovery, Katie Colson

Theses and Dissertations--Neuroscience

Age-Associated B cells (ABCs) are atypical memory B cells commonly expressing CD11b, CD11c, and T-bet. We hypothesized that aged female mice would have worse functional outcomes after stroke due to higher brain-localized ABCs. We identified 6 ABC subsets expressed in the brain, with higher levels in uninjured animals versus 3 weeks after stroke. Contradictory to my hypothesis, aged uninjured males with higher numbers of Classical ABCs (CD11bhighCXCR5+/CXCR5-) in the brain exhibited better motor function, though with limited differences by injury or sex for other classical ABC subsets. Rare CD11b+CXCR5+ populations from uninjured mice secreted more IFN-γ when exposed to TLR7/9 …

Genetic And Metabolic Factors Shaping Functional And Systemic Recovery Post-Spinal Cord Injury: A Focus On Apoe, Chase Taylor

Theses and Dissertations--Neuroscience

There are currently approximately 300,000 individuals living with a spinal cord injury (SCI) in the United States with an additional 17,000 injuries occurring each year. Perhaps of equal importance the median age at which an SCI occurs within the population has steadily increased since the 1970s to the 2010s from 29 years to 43 years and is still on the rise. Women, historically underrepresented in biomedical research, have also seen a slight increase in SCI incidence. This increase in age of injury onset means that more people with an SCI will be impacted by genetic factors associated with Alzheimer’s disease …

What’S Harm Reduction Got To Do With It? A Study Of The Implementation Of Substance Use Management Practices Among A Sample Of U.S. Domestic Violence Programs, Stephanie H. Ratliff

Theses and Dissertations--Social Work

Domestic violence programs are essential resources for survivors of intimate partner violence (IPV). Programs offer services that go beyond providing safety and shelter. To improve outcomes, program staff have expanded services to meet the needs of survivors. One population of survivors that has gained attention in the peer-reviewed literature is survivors who use substances (SWUS). These survivors have unique needs and are at increased risk of IPV due to substance misuse. Research about the support available to SWUS after they access shelter is scarce. Using cross-sectional data from a national sample of 97 U.S. domestic violence programs, this study describes …

Fathers’ Perspectives On The Role Of Spirituality In Substance Misuse Disorder Treatment And Engaging With Their Children, Kendra Michelle Eubank

Theses and Dissertations--Social Work

The father's role and the extent of involvement with his children have shifted over the past several decades. As a result, researchers have made considerable advances in understanding paternal influences on child development and families. However, one under-researched topic is how fathers' substance misuse, and the recovery process may influence father involvement and effective co-parenting, and specifically, how spirituality plays a role in that. In this qualitative study, fourteen participants participated in semi-structured interviews. The data revealed two main themes: 1) pillars of a spiritual awakening and 2) applying spirituality to healthy fatherhood engagement.

These findings led to four interpretations: …

The Performance Of Marginal Modeling Methods For Rare Events With Application To Opioid Overdose Mortality And Morbidity, Shawn Nigam

Theses and Dissertations--Epidemiology and Biostatistics

Opioid misuse is a nationwide epidemic, with Kentucky having one of the highest opioid overdose-related fatality rates across all US states. These rates have increased significantly over the past decade, with particularly large increases during the COVID-19 pandemic. This dissertation aims to study the behavior of these increases and the methods for the marginal modeling of count outcomes related to opioid overdose.

Opioid overdose-related fatality rates in Kentucky increased significantly during the COVID-19 pandemic. In this chapter, we characterize the changes in opioid overdose fatality rates in Kentucky and identify associations between potential factors and fatality rates. County-level opioid overdose …

Why Do My Coworkers Share Their Work-Related Good News With Me? Coworker Capitalization, Motive Attribution, And Implications, Chenduo Du

Theses and Dissertations--Management

While research on close relationships suggests that individuals can benefit from capitalization or sharing positive events, it is unclear whether similar benefits hold for coworker capitalization or sharing work-related positive events with coworkers. Given that coworkers typically possess less intimate knowledge of one another compared to those in close relationships, it is plausible that they may interpret each other’s actions in diverse ways. Thus, I introduce attribution theory as a novel framework for understanding the effects of coworker capitalization. I suggest that when a coworker shares a positive event, recipients may attribute one of three motives to the discloser: a …

A Praxis Towards Social Change Based On Foucault's Conceptualization Of Experience As Relational, Lila Maureen Wakeman

Theses and Dissertations--Philosophy

This project develops a praxis towards social change based on the works of Michel Foucault. It first establishes Foucault’s philosophical assumptions, methods, and political goal of countering “objectivizing” modern Western social forces. It then draws on sources from the three major phases of Foucault’s career to trace his development of a general conceptualization of experience as relational, or as non-exhaustively co-constituted by and through three indispensable kinds of social forces: knowledge, power, and ethics. It then evaluates implications of Foucauldian experience for efforts towards social change to conceptualize a general Foucauldian praxis towards social change. The praxis aims to affect …

On The Principles And Ends Of Education: A Thomistic Approach, Keith Parkinson

Theses and Dissertations--Philosophy

This dissertation develops an account of the nature of education from a Thomistic point of view. The thesis is that education is best understood as ‘human growth’—growth, because it is the natural development of potentialities inherent within the human person toward full actualization, and human, because it pertains in particular to those faculties of reason that are unique to human beings among all natural creatures, the intellect and will. The first three chapters provide an overview of Thomistic anthropology and virtue theory, from which I conclude that the final goal toward which all genuinely educational activity aims is the speculative …

Hegelianism As Anti-Authoritarianism, Tyler Van Wulven

Theses and Dissertations--Philosophy

My dissertation intervenes in two ongoing conversations about the nature of freedom. The first seeks to understand and combat the allure of authoritarianism. The second, rooted in 19^th and 20^th century philosophy, sheds light on this phenomenon by suggesting that the acknowledgment and endorsement of the social and historical origins of our normative commitments would awaken us to our radical freedom. My dissertation contributes to this conversation by suggesting that authoritarianism is rooted in a failure to comprehend ourselves, and that a proper investigation into human selfhood is needed to understand and actualize our powers of self-determination. Drawing …

Relationality In Rousseau's Philosophy Of Education, Thayne Cameron

Theses and Dissertations--Philosophy

Jean-Jacques Rousseau’s assertion of Emile that “Our true study is that of the human condition” serves as the foundation for this dissertation, which examines the significance of certain kinds of basic experiential relationships in Rousseau’s philosophy of education. By analyzing the relationships between the self and objects, the self and others, and the educator and the learner, this work elucidates how these interactions underpin Rousseau’s pedagogical views and their implications for fostering personal and social virtue.

The dissertation explores the self-object relationship through affectivity, embodiment, and purposeful activity, demonstrating how direct engagement with objects shapes perceptions and behaviors. It then …

Location, Location, Location: Geographic Qualities Of Political Instability And Military Coups, William O'Connell

Theses and Dissertations--Political Science

Previous research has shown that political instability can lead to military coups, especially when it occurs close to the capital. However, other than proximity to the capital, no other geographic qualities of instability and their relationship to coups have been explored. Therefore, this dissertation serves as a detailed analysis of how the location of instability conditions its impact on coups.

To show how the locational qualities of instability influence coup likelihood, I borrow from expected utility models of coups, and explore how instability influences militaries’ disposition and ability to coup differently when it occurs in different areas within a country. …

Speaking, Running, Leading: Black Women In American Politics, Sherelle A. Roberts

Theses and Dissertations--Political Science

This dissertation examines African American women as constituents, candidates, and policy entrepreneurs. It illuminates the ways in which Black women navigate the complexities of politics, while balancing their equally complex intersectional identities. It critiques the notion of African American women as politically marginalized actors and highlights the ways in which they surmount social, cultural, and political disadvantage to gain political success.

Recovery Capital In A Justice-Involved Population: An Asset-Based Approach To Recovery And Community Reentry, Evan Joseph Batty

Theses and Dissertations--Sociology

The burden of the opioid epidemic demands further efforts to facilitate recovery, particularly for disadvantaged populations and those recently released from prison. After community reentry, individuals face a period of vulnerability as they adjust to new roles and responsibilities to meet their basic needs. Prison-based substance use disorder treatment (SUD Tx) programs provide support to help prepare individuals with SUD for their release and facilitate successful recovery goals after community reentry. This dissertation has three aims: (1) further the understanding of potential barriers and facilitators of recovery after community reentry, (2) assess how prison-levels of recovery capital influence recovery outcomes …

Variable Selection For High-Dimensional Data With Interaction Effects: Methods, Applications, And Inferences, Leiyue Li

Theses and Dissertations--Statistics

For high-dimensional data where the number of variables greatly exceeds the number of observations, selecting important variables while maintaining the required heredity conditions can be challenging. This dissertation is structured into three interconnected parts. In the first part, we propose a variable selection method by implementing a well-known optimization technique, the Genetic Algorithm. An R package was developed to simplify the implementation and usage of the proposed method. We then propose another variable selection method by extending the study from the Genetic Algorithm to a different but related optimization technique, Simulated Annealing. We consider three different hierarchical structures in both …

High-Dimensional Tests And Projection Methods: Subvector Analysis And Matrix Variate Data, Shouryya Mitra

Theses and Dissertations--Statistics

In this dissertation, we study projection-based methods to testing problems for high-dimensional data. We also investigate inferential methods for matrix variate data with block compound symmetry (BCS) covariance structure. The research reported in dissertation consists of three projects.

The first project addresses power loss and ill-conditioned error covariance estimates commonly faced by multivariate tests in high-dimensional settings. To overcome these challenges, previous approaches avoided correlations in constructing test statistics, but this required strong assumptions about covariance matrices and dependence structures. More recently, some methods have incorporated correlations by employing random projection into a lower-dimensional space. We develop a unified framework …

Estimation And Testing Of Nonparametric Effects Of Incomplete Multivariate And Repeated Measures Data, Swetalina Maity

Theses and Dissertations--Statistics

In this dissertation, we investigate three distinct but interrelated problems in analyzing repeated measure data with missing values.

The first project is on semiparametric methods for analyzing repeated measures designs with missing values. A closed-form estimator for the parameters and their asymptotic covariance are derived using block partitioning based on the missing data pattern. We also derive the asymptotic distribution of the estimators and construct test statistics to test hypothesis formulated as linear contrasts of the mean vector.

In the second project, we focus on purely nonparametric methods. In this setup, nonparametric treatment effects are defined as functionals of the …

From Non-Parametric Methods To Self-Supervised Learning: Applications In Edge Detection And Image Denoising, Jiacheng Xu

Theses and Dissertations--Statistics

This dissertation explores advanced methodologies for edge detection and image denoising through the application of both traditional non-parametric methods and modern self-supervised deep learning techniques. Beginning with non-parametric approaches, we refine surface fitting and jump detection criteria to enhance the detection of discontinuous regression surfaces in grayscale images. These foundational techniques are extended to color images, with analyses across RGB and CIELAB color spaces to improve edge detection accuracy. We then introduce a self-supervised neural network model that integrates Masked Modeling into the Bi-Directional Cascade Network (BDCN) framework. This approach shows the potential of reducing the dependency on annotated data …

Intentions To Seek Mental Health Services Among Nursing Students In The United States: The Impact Of Adverse Childhood Experiences And Psychological Distress, Zainab Almogheer

Theses and Dissertations--Nursing

Supporting the mental health of university/college students is a crucial issue facing institutions of higher learning in the U.S. A web-based survey encompassing 196 campuses in the U.S. found that rates of diagnosed mental illness among college students has significantly increased in the last decade from 21.7% in 2007 to 35.5% in 2017 (Lipson et al., 2019). Despite the availability of mental health services within universities/colleges, students with mental health problems do not often utilize these services. Recognizing the significance of assessing the mental health of nursing students is paramount, as evident from a study where 35% of 170 participants …