Digital Commons Network^™

A Machine Learning Approach To Constructing Ramsey Graphs Leads To The Trahtenbrot-Zykov Problem., Emily Hawboldt

Electronic Theses and Dissertations

Attempts at approaching the well-known and difficult problem of constructing Ramsey graphs via machine learning lead to another difficult problem posed by Zykov in 1963 (now commonly referred to as the Trahtenbrot-Zykov problem): For which graphs F does there exist some graph G such that the neighborhood of every vertex in G induces a subgraph isomorphic to F? Chapter 1 provides a brief introduction to graph theory. Chapter 2 introduces Ramsey theory for graphs. Chapter 3 details a reinforcement learning implementation for Ramsey graph construction. The implementation is based on board game software, specifically the AlphaZero program and its …

Kdm5b As A Potential Epigenetic Regulator Of Cardiomyocyte Regeneration And Cell Cycle Activation., Dana Hammouri

Electronic Theses and Dissertations

The limited regenerative capacity of adult cardiomyocytes (CMs) is manifested in prevalent morbidity and mortality associated with ischemic heart disease. We previously demonstrated that a combination of four cell cycle factors (4F) promotes efficient cell division in differentiated CMs. The temporal transcriptional reprogramming in the 4F-transduced CMs indicates that epigenetic modifications mediate the cell cycle progression. Through small molecule screening, we evaluated the epigenetic impact on CM’s response in the 4F-transduced CMs. We identified the histone demethylase 5B (KDM5B), which through in vitro and ex vivo genetic knockdown and overexpression studies, exhibited a modulative effect on CM’s cell cycle plasticity …

Development And Application Of A Microfluidic Platform For Quantifying Intra-Tumoral Compressive Stress., Zachary P. Fowler

Electronic Theses and Dissertations

Cancer progression is linked to the emergence of aberrant mechanical signaling in the tumor microenvironment. Modulation of extrinsic signals, such as ECM stiffness and composition, have been thoroughly explored. However, the development of solid stresses within the tumor remains poorly understood. To address this, we have developed a microfluidic platform that generates deformable alginate microbeads that allow for the quantification of compressive stresses generated within a growing glioblastoma (GBM) tumorsphere. PDMS microfluidic devices were fabricated via SU-8 mold with channels ranging from 10µm-40µm in diameter. Fluorescently labeled sodium alginate underwent a cross-linking reaction within the device to generate monodisperse beads …

Public Space And Well-Being: An Empirical Study Of Central Park In Old Louisville., Maryam Entezam

Electronic Theses and Dissertations

Urban green spaces have been receiving attention in urban planning and the health profession in the 21^st century as environmental elements that contribute to well-being. This dissertation explored the relationship between green space usage and individuals’ physical, mental, and social well-being. This empirical research focused on Central Park in Old Louisville to examine how residents use the park and whether it contributes to the well-being of residents. After exploring the existing literature, I identified four well-being indices: (1) perceived health (PHI), (2) health outcome (HOI), (3) mental well-being (MWI), and (4) social well-being (SWI). Frequent Park usage is expected …

The Emotional Intelligence And Conflict Management Relationship In Black Women Leaders, Tina Raylyn Jackson

Electronic Theses and Dissertations

This study examined the relationship between emotional intelligence and conflict management styles in Black women leaders in the United States. The lack of literature surrounding Black women leaders' emotional intelligence or conflict management styles presented an opportunity to offer quantitative data connected to these constructs. A cross-sectional survey design was used to administer three surveys the Situational Test of Emotional Management- B, the Kraybill Conflict Style Inventory, and a modified version the Multidimensional Inventory of Black of Identity, that focused on Black female identity. Data from 124 participants were analyzed to learn if identity mediated the relationship between emotional intelligence …

Understanding Barriers That Exist To Campus Administrators’ Support For Special Education Programs And How Principals Use Special Education Needs Coordinators As Change Agents, Kevin L. Lanxon

Electronic Theses and Dissertations

Several barriers exist that impact campus administrators’ use of special education needs coordinators (SENCOs) as change agents. Using grounded theory, this study aimed to understand the barriers that exist for campus administrators regarding their ability to support special education programs and how principals use SENCOs as change agents. The study was conducted on a secondary campus with participants engaging in participatory action research (PAR) within a professional learning community. Data was collected using a triangulation of PAR forms, interviews, and reflective journals. While the study focused on understanding the barriers that impact administrators utilizing their SENCOs as campus leaders, the …

“Just As Scared As I Am”: Daughters’ Perspectives Of The Impact Of The Overturning Of Roe V. Wade On Mother-Daughter Reproductive Conversations, Casadie Smith

Electronic Theses and Dissertations

Existing literature has identified mothers as the primary reproductive educators of their daughters and has determined mother-daughter conversations about reproduction to be an indicator of daughters’ sexual and reproductive behaviors. The overturning of Roe v. Wade on June 24, 2022, had an immediate impact on the reproductive lives of many people, including daughters. Through one-on-one interviews with 10 daughters, this qualitative study identifies three changes in mother-daughter reproductive conversations that were influenced by the overturning of Roe v. Wade: (a) The initiation of conversations, (b) the topics of conversations, and (c) the tone of these conversations. The results of this …

Lightweight Blockchains And Their Network Impact On Vehicular Ad-Hoc Network-Based Blockchain Applications, Edgar Bowlin

Electronic Theses and Dissertations

Vehicular Ad-hoc Networks (VANETs) provide networks for smart vehicles and will enable future systems to provide services that enhance the overall transportation experience. However, these applications require consideration to possible damage to both property and human life. Communication between vehicles requires data immutability and user privacies to provide safe operation of the system. Blockchains can provide these properties and more to create a more secure and decentralized system. However, a chain’s security comes from the chain length. VANETs’ ephemeral connections provide harm limits how much data can be exchanged during vehicle rendezvous. This thesis investigates lightweight blockchains that operate with …

Met Alterations In Glioblastoma: Characterization Of Patient-Derived Xenografts And Therapeutic Strategies, Anna Musket

Electronic Theses and Dissertations

Glioblastoma is the most commonly diagnosed central nervous system primary malignancy and it is considered a terminal diagnosis with few treatment options available. Glioblastoma tumors frequently develop treatment resistance due in part to their highly heterogenic nature. The heterogeneity of glioblastoma is partially attributed to the presence of glioma stem-like cells (GSC), which are highly invasive and resistant to chemotherapy and irradiation treatments. Signaling of the receptor tyrosine kinase MET is a known regulator of GSC. Glioblastoma patients have an increasingly poor prognosis that corresponds with increasing MET expression. Both GSC and MET are known to contribute to treatment resistance …

Use Of Transposon Screening For Salicylic Acid-Assisted Desiccation Killing In Salmonella, Shannon D. Elliott

Electronic Theses and Dissertations

Salmonella enterica serovar Typhimurium is one of the most prevalent food-borne pathogens, affecting millions around the world every year, making it a threat to global health. Salmonella possesses the ability to survive the normally lethal condition of desiccation, however, discovery of the genes and mechanisms behind this phenomenon are still ongoing. Using a transposon mutagenesis approach to construct a broad transposon library, this study aimed to uncover genes that may be contributing to changes in Salmonella’s survivability under desiccation, particularly when exposed to the antimicrobial molecule salicylic acid. Building on previous findings showing salicylic acid can alter cell viability …

Femoral Osteohistology In American Alligators (Alligator Mississippiensis) Reveals High Variation In Growth And Facilitates Interpretation Of An Early Pliocene Alligator, Davis Gunnin

Electronic Theses and Dissertations

Histological analysis of long bone thin sections is commonly used to infer growth rates and ecology of extinct vertebrates, particularly within Archosauria. However, most comparative neontological studies have used small samples of captive individuals, limiting the scope of variation. To fill this gap, 44 femoral thin sections of wild Alligator mississippiensis were prepared and analyzed. Comparison of slides revealed that larger individuals from cooler climates tend to show more LAGs compared to southerly A. mississippiensis of similar size, however, there is considerable variation. This pronounced variation in wild specimens emphasizes the need to use caution when interpreting paleohistological data with …

Effects Of Environmental Pollutants On Liver Disease: Role Of The Gut-Liver Axis., Ngozi Victoria Adiele

Electronic Theses and Dissertations

Polychlorinated biphenyls (PCBs) and polystyrene (PS) microplastics are environmental pollutants associated with various diseases including toxicant associated fatty liver disease (TAFLD). Previously, exposure to Aroclor 1260 (a PCB mixture) has been shown to exacerbate TAFLD, partly through Aroclor 1260 induced gut dysbiosis. Studies has also demonstrated that PS exposure alters gut microbiome composition and induced obesity. However, the effects of Aroclor 1260 on the gut and the effects of PS on the liver are still understudied. Therefore, we hypothesize that environmental pollutants will disrupt the gut-liver axis through changes in gut and its microbiome as well as changes in liver …

Effects Of Parental Deployment On Military-Connected High School Students And Strategies For Academic Success, Sean T. Lucas

Electronic Theses and Dissertations

Abstract The problem investigated in this study was unknown opportunities that exist for educators to meet the academic needs of students who are affected by combat parental deployment and how this challenge of combat deployment disrupts the family’s dynamic, thus challenging their children academically. The Air Force, Army, Navy, Marines, and Coast Guard made up about 1% of the total United States population in 2015. Most of these people were married, 42% had children, and 54% of their children were in kindergarten to 12th grade. The Department of Defense school system is comprised of 166 accredited schools across 11 foreign …

Liberation And Inclusion Through The Voices Of Trans Youth: A Phenomenological Approach, Klaudia Neufeld

Electronic Theses and Dissertations

The primary aim of this phenomenological study is to elevate trans youth voice to understand the essence of their individual and shared lived experiences within school systems designed for them to be silenced, excluded, and erased. In alignment with Eve Tuck’s desire-based research, this study is designed to counter deficit narratives of trans youth. Participants include six racially and ethnically diverse trans youth, ages 13−17 in the U.S. state of Colorado. Analyses revealed four themes: a gender-identity transition journey; navigating geography; safety and the impact of school culture; creating belonging through a coalition of community and friendship; and youth lessons …

Fostering An Inclusive Learning Environment Through Course Development: A Program Evaluation, Rachel K. Rogers

Electronic Theses and Dissertations

This evaluation was chosen to address the desire of students to see themselves and their lived experiences in their coursework at University College, the location of this study. The purpose was to complete a utilization-focused evaluation that assessed first, the formal and informal practices involved in the course development process within an academic department at University College, University of Denver, and second to determine the extent to which the course development process contributes to an inclusive learning environment. Data were collected using qualitative methods including semi-structured interviews of key stakeholders in the course development process, observations of weekly course development …

A Qualitative Inquiry Of Research Administrator Perceptions Of Job Satisfaction In A Central Research Administration Unit At The University Of Denver, Noelle L. Strom

Electronic Theses and Dissertations

The Sponsored Programs Administration (SPA) team provides critical research administration services for the research community at the University of Denver. As research funding continues to rise at the University of Denver, retention of research administrators is critically important. Job satisfaction is key to employee engagement and retention. Higher job satisfaction contributes to several positive outcomes for institutions, including lower turnover, higher productivity, lower costs, and employee loyalty. The need to retain experienced research administration professionals is highlighted by the fact that few formal educational routes exist that prepare employees for a career in research administration; rather, developing expertise takes a …

“Difference In/At The Center" A Transnational Approach For Mobilizing International Multilingual Graduate Writers' Writing Assets During Writing Instruction., Olalekan Adepoju

Electronic Theses and Dissertations

This research project presents an empirical exploration of how the writing assets possessed by international multilingual graduate writers impact the theory and pedagogical practices in writing studies, especially regarding the approaches to teaching writing. Extant scholarship in writing studies, especially on second language research/teaching, translingual writing practices, and asset-based writing pedagogy has engaged issues of difference in language, race, culture, as well as funds of knowledge, highlighting the impacts of these differences on the academic success of non-native English speakers in US schools and colleges. My dissertation builds on these trends and highlights the narratives, perceptions, and experiences of international …

Where Are All The Women?: Using Role Congruity Theory To Explore The Experiences Of Female Interscholastic Athletic Directors., Nicholas Swim

Electronic Theses and Dissertations

Leadership in sport organizations continues to be male dominated, even as multiple scholars have argued and proven the importance of women holding sport leadership positions (Burton & Leberman, 2017; Darvin & Lubke, 2021; Schull, 2017). The lack of women attaining these positions leads to fewer opportunities for role modeling and mentoring experiences for female athletes. As Burden et al. (2010) argue, interscholastic athletic directors are important as they usually represent the first interactions for young athletes with people in sport leadership positions. Researchers have investigated this phenomenon at the intercollegiate level (Bower & Hums, 2013; Darvin & Lubke, 2021; Taylor …

Tropical Understory And Canopy Twig Ants (Pseudomyrmex): Natural History, Sensory Homing, And Neuroecology., Daniella Prince

Electronic Theses and Dissertations

In this dissertation, I examined the behavior of foraging twig ants, explored the sensory profile of their homing behavior, and investigated the role of habitat use in shaping the sensory neurobiology of species within the genus Pseudomyrmex (Hymenoptera: Formicidae). In chapter one, I reviewed the ecology of Pseudomyrmex, and introduced the focal species, P. boopis, a neotropical understory-dwelling twig ant. In chapter two, I described the natural history of P. boopis on Barro Colorado Island, Panama—specifically, their nesting habits, activity rhythm, and foraging behavior on understory surfaces. Pseudomyrmex boopis colonies were diurnal and nested in dead twigs in …

Intercalation And High-Pressure Investigations Of Black Arsenic Phosphorus: Unraveling Material Transformations., Dinushika Vithanage

Electronic Theses and Dissertations

Black arsenic phosphorus (b-As_yP_1-y) alloys have emerged as intriguing materials within the realm of two-dimensional (2D) materials, following the discovery of black phosphorus (BP). These alloys possess capability to overcome major limitations of BP and exhibit potential for tunability and enhancement of properties making them promising materials for a wide range of applications, including lithium-ion batteries. Inspired by the intriguing findings obtained for BP, this research focuses on understanding the structural modifications that can be achieved in b-As_yP_1-y alloys through the application of intercalation and high pressure. The initial phase of our investigation …

Investing In Your Employees: Understanding The Impact Organizational Commitment Has On Staff Retention, Vanessa Lynne Mcwhirt

Electronic Theses and Dissertations

High employee turnover in higher education has been an issue for decades, and successfully integrating newly hired staff (NHS) into their new job and the organization can be challenging for human resources and leadership. New employee orientation and onboarding programs can assist NHS. The author of this paper conducted a Utilization-Focused evaluation of the Thriving at DU program at the University of Denver (DU) to improve the program. The study examined the perceptions of how 12 student and academic affairs professionals made meaning of organizational commitment in the workplace throughout their onboarding experience.

The major findings of this evaluation aligned …

Institutional Racism, Racial Trauma, And Mental Health In Bipoc Graduate Students And Professionals., Jody Zhong

Electronic Theses and Dissertations

While there is increasing mainstream focus on diversity, equity, and inclusion (DEI) amongst U.S. college campuses, institutional racism and everyday racist events continue to be common experiences for Black/Brown, Indigenous, and People of Color (BIPOC) students (Bartz, 2019; Noltemeyer et al., 2012; Pieterse et al., 2010; Regis, 2016; Vaishnav, 2020). Research has shown that subtle, everyday racist slights, known as microaggressions, can have a substantial effect on the mental health and functioning of BIPOC, leading to the development of posttraumatic stress and to negative impacts on psychological well-being (Abdullah et al., 2021; Le et al., 2021; Lui & Quezada, 2019; …

False Memories Are Impacted By Semantic Pairing Of Drm Lists., Ryan Coleman

Electronic Theses and Dissertations

In the DRM paradigm, experience of semantically related words leads to false memories of related words called critical lures. These false memories serve as evidence that the relationship between items in a DRM list contribute to an overall gist or central concept for the experience. The present studies aim to investigate whether the higher-order semantic relationship that exists between different DRM lists can also influence recognition memory. Study 1 compared memory confidence ratings for list items and critical lures to two metrics: “Temporal Contiguity”, how closely in time lists appeared to each other at encoding, and “Semantic Distance”, the semantic …

Stability Of Cauchy's Equation On Δ+., Holden Wells

Electronic Theses and Dissertations

The most famous functional equation f(x+y)=f(x)+f(y) known as Cauchy's equation due to its appearance in the seminal analysis text Cours d'Analyse (Cauchy 1821), was used to understand fundamental aspects of the real numbers and the importance of regularity assumptions in mathematical analysis. Since then, the equation has been abstracted and examined in many contexts. One such examination, introduced by Stanislaw Ulam and furthered by Donald Hyers, was that of stability. Hyers demonstrated that Cauchy's equation exhibited stability over Banach Spaces in the following sense: functions that approximately satisfy Cauchy's equation are approximated with the same level of error by functions …

Illuminating Underappreciated Mechanisms Of Receptor Regulation In Human Lymphocytes., Cassandra Woolley

Electronic Theses and Dissertations

A thorough understanding of receptor regulation is imperative to predict expression in varying contexts of disease or treatment. Lymphocyte surface receptors are often used as biomarkers and drug targets, making them particularly important for study. For receptors of debated functionality, such as the Fc receptor for IgM (FcMR), understanding regulation can also help to predict expression in vivo to supplement hypotheses of biological roles. Various mechanisms exist for altering receptor surface expression, including direct feedback mechanisms such as ligand-induced endocytosis and broader mechanisms such as transcriptional and translational control. In this dissertation, we explore selected underappreciated mechanisms of lymphocyte receptor …

Inhibition Of Ras As A Novel Therapeutic Approach In Luminal B Breast Cancer., Raphael Ngozichi Jigo

Electronic Theses and Dissertations

Historically, the RAS oncoprotein has not been implicated in breast cancer due to less than 1% of breast cancer cases bearing oncogenic RAS mutations. Recently, however, it has been reported that greater than 60% of Luminal B breast cancer cases have a decreased expression of negative RAS regulators RASAL2 and DAB2IP. Thus, in many Luminal B breast cancers, RAS remains in a constitutively active state without mutation, in turn driving oncogenesis. To date, there are no FDA-approved direct inhibitors of wild type RAS. We have developed a direct RAS inhibitor that acts on wild type RAS using in silico drug …

New Species Of Dryolestoid From The Late Cretaceous Allen Formation And Implications For South American Faunal Diversity., Brigid Erin Connelly

Electronic Theses and Dissertations

Dryolestoids are extinct cladotherians mammals from the Jurassic and Cretaceous periods. I describe a collection of dryolestoid specimens from the Late Cretaceous localities of Cerro Tortuga (Allen Formation), Anfiteatro 1, and Shining (both La Colonia Formation) from Patagonia, Argentina. Using comparative morphology, I identify a new species of meridiolestidan dryolestoid based on eleven specimens across both formations. The new species’ recovery from La Colonia Formation represents the first dryolestoid connection between the two approximately contemporaneous formations. The species’ morphology may represent an ecological shift within Meridiolestida from insectivory to herbivory, showing a transition in characters between the plesiomorphic sharp-toothed meridiolestidans …

Epitranscriptomic Regulation In Breast Cancer And Pcb-Induced Liver Disease., Belinda Petri

Electronic Theses and Dissertations

Post-transcriptional RNA modifications including N6-methyladenosine (m6A) regulate mRNA stability, splicing, and translation. My research examined m6A in two disease models: breast cancer (BCa) and non-alcoholic fatty liver disease (NAFLD). Acquired resistance to endocrine therapies (ET) develops in approximately 20% of BCa patients with estrogen receptor α positive (ER+) tumors following treatment. The mechanisms by which tumor cells evade ET are not completely understood. Using a cell line model, we investigated the role of an m6A reader protein, HNRNPA2B1 (A2B1) that is upregulated in ET-resistant ER+ BCa cells. Stable overexpression of A2B1 in ET-sensitive MCF-7 cells (MCF-7-A2B1), results in ET resistance, …

Non-Western Rendition Of Ambient Rhetoric Of Khajuraho Monuments., Shiva Hari Mainaly

Electronic Theses and Dissertations

This dissertation develops an ambient rhetoric: a living practice that is more disclosive than communicative, more entangled than intersectional, and more subtle than explicit and evidential. Rather than exploring the symbology, iconography, texture, and artistic integrity of Khajuraho monuments, I claim that Khajuraho monuments aim at convincing visitors with their persuadability and affectability inherent in their material bases, architectural panels, fractal design, allegorical cast, aura of attunement, and the environment in which the monument complex is nestled. Khajuraho groups of monuments in Central India, matchless in their monumentality, dynamic in their adjustment to the shifting socio-politico-cultural landscape in the world, …

Why Democracies And Autocracies Go To War: Comparing The Cases Of Iraq And Ukraine, Ketevan Chincharadze

Electronic Theses and Dissertations

History shows that both democratic and nondemocratic countries wage wars to advance their strategic interests. This study has comparatively analyzed two conflicts – the 2003-2011 U.S. invasion of Iraq and Russia’s ongoing war in Ukraine – to identify the trends that motivate both democratic and autocratic leaders to behave similarly by launching an invasion. The interpretive research of various memoirs, books, interviews, academic articles, news reports, and speeches, has uncovered that personal biases, particularly confirmation biases, play a significant role in motivating leaders to start a war. Leaders’ confirmation biases are often shaped by three prominent factors – historical memory, …