Digital Commons Network^™

Strategies To Support Students With Adhd During Self-Selected Reading: An Evaluation Of Token Economy And Self-Monitoring, Tora Henson

Dissertations

Students with attention deficit/hyperactivity disorder (ADHD) often face challenges with attention and executive functioning, making it difficult to stay on task during self-selected reading (SSR). These difficulties can hinder academic progress. While research highlights the need for effective strategies to improve on-task behavior, limited studies have focused specifically on self-monitoring and token-economy interventions during SSR. This study investigated the impact of self-monitoring and token-economy strategies on the on-task behavior of students with ADHD during SSR. It aimed to answer the following questions: How do token economy systems and self-monitoring strategies impact on-task behavior for students with ADHD during self-selected reading? …

Perceived Social Support And Religious Attitudes As Correlates Of Spiritual Well-Being Among Senior Undergraduate Students At Northeast Brazil Adventist University, Hebert Davi Liessi

Dissertations

Problem

Even though the study of spirituality has been a recurrent theme in academia, in Brazil there has been little emphasis on the analysis of spiritual well-being in the context of university students. Few studies have examined the correlation of spiritual well-being with perceived social support or religious attitudes among university students, and most of these have been in the fields of health care or health recovery. Some research has indicated that religious attitudes may be partially disconnected from improvements in the level of spirituality. -- This study aimed to verify whether this disconnection is real or relevant, and assumed …

Statistical Approaches In Evolutionary Biology: Using Threespine Stickleback Fish To Test Fisher's Geometric Model And Evaluate Methods For Handling Missing Data, Aaron Mathew Myrold

Dissertations

This thesis explores two distinct yet complementary aspects of evolutionary biology. The first chapter tests predictions from Fisher's geometric model of adaptation using a finely resolved fossil sequence of Gasterosteus doryssus spanning approximately 21,250 years. I analyze phenotypic changes in three armor traits during adaptation to a new environment and find that while step sizes follow the predicted exponential distribution—with many small steps and few large ones—they do not adhere to the model's temporal prediction that large-effect mutations should fix early in the adaptive walk. This discrepancy likely reflects adaptation from standing genetic variation rather than de novo mutation. The …

Genetic Architecture Of Complex Traits In African Ancestries Across Diverse Environments, Isadore Gregga

Dissertations

Given genetic and environmental diversity, genetic prediction based on African- ancestries individuals in the US or UK may not transfer well to other African diaspora regions. The Modeling the Epidemiological Transition Study (METS) is a longitudinal study of cardiometabolic health in five African-ancestry populations. We performed genome-wide genotyping in METS participants from the US, Jamaica, South Africa, and Ghana. We aimed to explore how genetic models for the transcriptome and body mass index (BMI) built using US- based African-ancestries populations perform in these four diverse populations. A subset of METS participants also had whole blood RNA-Seq data. For these, we …

Characterizing Niche Specialization In Staphylococcus Epidermidis, Sandra Jablonsk

Dissertations

This thesis investigates the microbial diversity of Staphylococcus epidermidis (S. epidermidis) across various anatomical sites in the human body. While traditionally viewed as a benign skin microbe, S. epidermidis also inhabits the urinary, gastrointestinal, and respiratory tracts, raising questions about its genetic variation and adaptability in different environments. The research aims to compare strains of S. epidermidis isolated from the oral cavity, nostrils, urinary tract, and skin of healthy individuals to determine if they share a common ancestor or if they evolved independently in response to specific environmental factors. The study comprises three main aims. Aim 1 focuses on assessing …

Interactions Between Microplastics, Biofilms, And Antimicrobials In Freshwater Streams, Ryan Thomas Krantz

Dissertations

Microplastics (MPs) are ubiquitous contaminants in freshwater ecosystems that could be hotspots for the interaction of antimicrobial compounds and surface-attached microbial biofilm communities. MPs and antimicrobials are both common in wastewater and urban freshwaters and MPs can adsorb contaminants like antimicrobials to their surface. Within aquatic habitats, MPs also support colonization by microbial biofilms. Therefore, we hypothesized that the adsorption of antimicrobials to MP surfaces would affect microbial communities colonizing MPs, altering their diversity, composition, and antimicrobial resistance. We investigated the effects of these interactions across two studies. The first study, discussed in Chapter 2, used a microcosm approach to …

Healthcare Providers’ Lived Experiences During Pivotal Change, Lisa Raynelle Shelley

Dissertations

This phenomenological study examined healthcare providers’ lived experiences of psychological safety and administrative leader behaviors that influenced those experiences during pivotal change. While much research addressed psychological safety among frontline healthcare staff, a gap was noticed concerning providers. This study aimed to investigate the impact of psychological safety and administrative support on provider engagement, emotional response, and retention during periods of significant change. Data were collected via a survey containing multiple-choice and open-ended questions, followed by semi-structured interviews. Four findings emerged. First, the providers’ pivotal events generated themes of “workplace power dynamics,” “systemic and organizational change,” “transformational crisis,” and “physical …

Toward Measurable Explainable Ethical Ai: An Llm-Driven Data Analytics Study, Greg Bacon

Dissertations

Large Language Models (LLMs) have been a hot area for popular and research audiences. Users marvel subjectively at Artificial Intelligence (AI) outputs — so much that OpenAI delayed public release of Generative Pre-trained Transformer 2 (GPT-2) back in 2019, citing ``safety and security concerns.'' This research advances ethical and transparent AI through qualitative and quantitative measures between user intent and LLM responses in a way that aims to assist users with clear indications of good and poor alignment and of where to backtrack to minimize bias and hallucinations. The use case is recommending grant topics in a United States Department …

Novel Ai/Ml-Based Frameworks For Protein Conformation Selection In Drug Discovery Applications, Shivangi Gupta

Dissertations

Drug development is a lengthy, expensive process with a high failure rate. The urgency brought on by the COVID-19 pandemic has accelerated the integration of artificial intelligence (AI) and machine learning (ML) to enhance drug discovery by increasing target specificity, reducing toxicity, and optimizing formulation strategies. Building on this momentum, this dissertation introduces novel AI/ML-driven frameworks for protein conformation selection and classification, addressing critical challenges in modern drug discovery. However, designing such a novel AI/ML data-driven framework is a difficult task because most real-world biomedical datasets suffer from class imbalance issues, which can significantly skew AI/ML model training, resulting in …

Manganism And The Development Of A Green Sustainable Low-Threshold Spectrophotometric Test For The Monitoring Of Manganese In Consumable Water, Anna Merritt Holmes

Dissertations

Manganism, a neurotoxic disease from the hyperaccumulation of manganese, follows an etiology that parallels Parkinsonism. Non-occupational Manganism is acquired by the lifelong accumulation of manganese through water contaminated by natural and industrial sources. Biologically active manganese (II) eludes flocculation and filtration removal methods at water utilities. The U.S. Standard Methods For the Examination of Water and Wastewater persulfate testing method uses mercury sulfate, concentrated nitric and phosphoric acids, silver nitrate, and ammonium persulfate. The low detection limit of 210 µg/L is an order of magnitude greater than the World Health Organization (WHO) allowable limit of 10-50 µg/L. In 2004, the …

A Rubber-Band System For Dynamic Incentivization Of Parallelized Gamified Objectives, Nicholas Diliberti

Dissertations

With the advent of videogames as the world's first mass-market interactive media, gamification has emerged as the premier way to harness powerful behavior-affecting gamified elements and place them in other contexts, such as education, fitness, and rehabilitation. This transposition, however, ignores a key tenant of user engagement: reward ought to be aligned with effort. Most, if not all, current gamification systems dispatch static reward allocations for their spread of gamified behaviors. In this paper, an alternative is presented: dynamic gamification. This dynamic gamification reads the user's current gamified state for indicators of aptitude, dynamically remaps rewards with a tuneable evaluation …

Understanding Pediatric Healthcare Access From A Black Parental Perspective : A Qualitative Study, Jessica A. Celestand

Dissertations

In the United States, healthcare access disparities have existed for several years in the African American/Black pediatric population. The District of Columbia ranks first nationally for health insurance coverage; however, African American/Black children have disproportionately experienced barriers to care compared to the District of Columbia’s pediatric population overall. There are current gaps in research that investigate African American/Black pediatric healthcare access from a parental perspective. The purpose of this descriptive phenomenology qualitative study was to explore research gaps by investigating barriers and facilitators to care, and the social determinants of health that impact pediatric healthcare access through the lens of …

Multipoint Observations Of Energetic Particle Acceleration Associated With Corotating Interaction Regions, Ashok Silwal

Dissertations

Stream Interaction Regions (SIRs) play a critical role in energetic particle acceleration and transport in the heliosphere. While shocks and compression regions associated with SIRs can accelerate particles to several MeV energies, most of our current understanding of these events is based on observations near 1 AU and beyond. Observations inside 1 AU, particularly by PSP and SolO, provide a unique opportunity to disentangle the roles of acceleration and transport. This dissertation presents the first detailed measurements of SIR-associated energetic particle events in the inner heliosphere between 0.15 and 0.80 AU using PSP, complemented by SolO and multi-spacecraft observations near …

Church Ministers' Perceptions On Burnout And How It Shapes Their Leadership Practices., Jason Young

Dissertations

This qualitative phenomenological study explored how large church ministry leaders experienced burnout and how that burnout shaped their leadership practices. The study was motivated by a research gap concerning the lived experiences of ministers in large churches. Framed by the job demands-resources theory and the conservation of resources theory, the study sought to understand how the demands of ministry leadership and the availability of personal and organizational resources influenced the experience of burnout. The research employed a qualitative phenomenological design, utilizing semi-structured interviews. A purposive and snowball sampling approach was used to recruit 13 large US church ministry leaders. The …

Bilingual Latinx Adolescents Experiences In A Predominantly White Institution: A Mixed Method Study, Danieli Marie Mercado Ramos

Dissertations

Extent scholarship has provided insight into how Latinx adolescents actively experience exclusion. These adolescents are often the targets of microaggressions tied to their language (Gonzalez et al., 2018), ethnicity, race, and intersecting identities--such as being bilingual Latinx students--which serve as reminders that they do not belong. However, little is known about Spanish-English bilingual Latinx adolescents and how their heritage language plays a role in predominantly white spaces and institutions. This convergent parallel mixed methods study explored how Spanish-English bilingual Latinx students in the Midwest described their experiences in a predominantly white institution (PWI). A total of 42 Spanish-English bilingual Latinx …

Evolution Of Bacteria: The Subsequent Relationships Between Different Species And Their Hosts, Helen Appleberry

Dissertations

To explore the relationship between two recently identified bacterial species (S. anginosus and S. urinae), three aims were designed. First, niche ranges were identified via two metagenome databases. Different niche ranges were identified between the two groups. S. urinae was more specific to the urogenital tract. S. anginosus appeared to be present across human anatomical niches. Secondly, specific genes to the S. urinae group were identified. This gives insight into the genomic and phenotypic differences previously identified. Thirdly, a temporal study was created to view S. urinae in female urine over 8 weeks. This showed stability in the urinary microbiome …

Deciphering The Source Of Escherichia Coli In Urinary Tract Infections: A Comparative Metagenomic Analysis Of The Female Urogenital Microbiome, Alexis Annabel Avalos

Dissertations

In 2019, there was a 140.19% increase in deaths due to urinary tract infections (UTIs) compared to 1990, worldwide. One of the common uropathogens known to associate with UTIs in females is Escherichia coli. The prevailing belief is that E. coli in the bladder originates in the rectum, passing its way from the perineal, to the vagina, and finally into the bladder. Known as the Fecal-Perineal-Urethral (FPU) hypothesis, this “origin story” has been supported by several studies that have relied on genotyping or serotyping isolates collected from the bladder and rectum. Most notably, culturing isolates from samples has been central …

Selecting For Lysis In A Temperate Phage Population, Haley Atkins

Dissertations

The ongoing evolutionary arms race between bacteria and bacteriophages (phages) is a prime example of Red Queen hypothesis, where continuous adaptation drives survival. This study focuses on Escherichia coli-infecting temperate phages, which dominate natural environments and contribute to bacterial resistance mechanisms. Despite their prevalence, temperate phages are less suited for phage therapy due to their lysogenic life cycle, where they integrate into bacterial genomes instead of lysing the host. In contrast, obligately lytic phages, which directly lyse bacterial cells, are ideal for therapeutic use but occur less frequently in nature. This research aims to select for lytic behavior in temperate …

Reconceptualizing Christian Nationalism, Robert Stevenson

Dissertations

This thesis sets out to critically engage with existing research on Christian nationalism. It argues that current research suffers from a methodological focus that is too broad, and theoretical grounding that is too imprecise, both of which prevent researchers from grasping the full scope and intent of Christian nationalism, as imagined by Christian nationalists themselves. Drawing on data collected from X accounts (formerly Twitter) of Christian nationalist users, Christian nationalist podcasts, and Christian nationalist books, it employs qualitative content analysis, mapped to Bourdieusian field theory to provide a structured approach for the understanding complex data involving multiple spheres of power, …

Refining Cross-Population Polygenic Risk Scores Across Diverse Populations, Mansi Patel

Dissertations

Large biobanks containing whole genome sequences connected to the deidentified electronic health records of hundreds of thousands of individuals are increasingly available to researchers. This has facilitated the development of polygenic risk scores (PRS), which use machine learning to predict risk of disease and other phenotypes from millions of genetic variants. Due to Eurocentricity of available genetic data, PRS have primarily been trained in populations of European descent. Differences in allele frequencies, effect sizes, and linkage disequilibrium patterns between populations can limit the transferability of PRS across different populations. Given that most data are from European genetic ancestry populations, we …

The Impact Of Lactobacillus Supplementation On Gut Microbiome Composition And Phage Induction In Mice, Kimia Boreiri

Dissertations

The mammalian gastrointestinal (GI) tract harbors a dense and dynamic community of microbes known as the gut microbiota, which plays vital roles in digestion, immunity, and overall health. Among these, probiotic bacteria such as Lactobacillus strains have garnered attention for their ability to influence microbial community structure and host physiology. This study investigated the effects of five Lactobacillus strains, Lactobacillus casei R1A482, Lactobacillus casei O3, Lactobacillus rhamnosus GG, Lactobacillus gasseri ATCC 33323, and Lactobacillus paragasseri UMB1065, on the gut microbiome of Swiss Webster mice over a six-week feeding period. To reduce stress, mice were fed Lactobacillus strains using gelatin pellets …

Decoding The Origins Of Infection: A Machine Learning Framework, Nirupama G. Shanbhag

Dissertations

Many infections can be attributed to a specific microorganism. For example, while there can be many causes of urinary tract infections (UTIs), such as the bacterial species Klebsiella pneumoniae or Enterococcus sp., the most widespread cause for UTIs is uropathogenic Escherichia coli. Generally, diseases or infections that are the result of a single pathogenic organism are more easily understood. Other diseases, such as irritable bowel disease (IBD), cannot be attributed to one member in the community; rather, it is a result of dysbiosis of the microbial community (microbiota) of the gastrointestinal tract, a combination of an overgrowth of problematic members …

Anti-Inflamatory Mechansim Of Bacillus Subtilis Derirved Exopolysaccharide, Adrian Taylor Ibarra

Dissertations

Exopolysaccharides (EPS) secreted by the commensal bacterium Bacillus subtilis exhibit potent anti-inflammatory properties, yet the underlying molecular mechanisms remain incompletely understood. We hypothesized that EPS reprograms antigen-presenting cells toward a tolerogenic state by modulating TLR4–MyD88 signaling. To test this, we began using a chemically defined, high-yield EPS production and purification protocol that largely eliminates protein and DNA contaminants, thus improving functional reproducibility across experiments using this new method. In vitro, EPS engaged TLR4 on murine dendritic cells (DC2.4) without inducing classical NF-κB activation, seen by LPS stimulation. Rather, EPS treatment upregulated inhibitory molecules, PD-L1 and PD-L2 while leaving activation markers, …

Investigating The Mechanism Of Resistance To Ido1 Enzyme Inhibitor Treatment In Human Glioblastoma, Kyla Shivakumar Hatton

Dissertations

Glioblastoma (GBM) is the most common and most aggressive form of adult cancer in the central nervous system, with GBM accounting for the majority of all malignant brain tumors. GBM is currently considered to be an incurable form of cancer, with over 14,000 patients diagnosed in the United States last year. Given the success of immunotherapy for treating other types of cancer, our group has investigated the possibility of therapeutically neutralizing immunosuppressive indoleamine 2,3 dioxygenase 1 (IDO1) in patients with GBM. Canonically, IDO1 is an immunosuppressive cytoplasmic enzyme that catalyzes the first step in metabolizing L-tryptophan into L-kynurenine (ie. ↓L-Trp→↑L-Kyn). …

Developing Chemically Defined Serum-Free Medium For Leukemic Blast And Stem Cell Expansion, Carmen Eva Finley

Dissertations

The relapse and chemotherapy resistance are the major challenges of acute myeloid leukemia (AML) treatment, driven by a rare population of leukemia stem cells (LSCs). LSCs are unique types of cells which evade standard chemotherapies and can regenerate AML post-treatment. Targeting LSC therapy remains limited, in part due to the lack of reliable in vitro AML culture systems to grow LSCs for drug discovery. This study aimed to engineer a chemically defined, serum-free 2D in vitro culture condition that supports either the expansion of leukemic blasts (LBs) or primary human LSCs by optimizing current protocols for hematopoietic stem cells (HSCs) …

Investigating Whether Txnrd2 Is A Therapeutic Target Against Triple Negative Breast Cancer Using African American-Derived Models, Keacha Chang

Dissertations

Despite similar breast cancer incidence rates, African American (AA) women experience a 40% higher mortality rate compared to Caucasian American (CA) women. This disparity is multifactorial and particularly pronounced in the Chicago area. AA women are twice as likely to be diagnosed with triple-negative breast cancer (TNBC), often at a younger age and with more aggressive disease. TNBC is a heterogeneous subtype lacking targeted therapies and is associated with the poorest prognosis among breast cancer types. Therefore, there is an urgent need for novel therapeutic strategies for TNBC, especially those tailored to AA patients. The thioredoxin pathway is essential for …

Capturing Diverse Adolescents’ Social Contexts: The Development Of An Ethnic-Racial Microaffirmations Scale For Peer Interactions, Maria Radulescu

Dissertations

The development of a strong and positive sense of ethnic-racial identity (ERI) has been identified as an asset for ethnically and racially marginalized adolescents. Peer interactions during the adolescent years can support ERI development. In particular, a subtle micro-level form of peer support—microaffirmations—may be protective for ERI processes. However, the field of microaffirmations is very small, and there is no scale that captures adolescents’ experiences of ethnic-racial microaffirmations from their peers. The current study developed an ethnic-racial peer microaffirmations scale based on extant literature and feedback from 4 focus groups with 22 sophomore high school students. Findings indicated that 5 …

The Bacterial Sensing Nuclear-Oligomerization Domain 2 Receptor In The Brain: Location And Potential Function, Julia Smyth

Dissertations

Nucleotide-binding oligomerization domain-2 (NOD2) is a cytosolic receptor, activated by bacterial peptides that initiates innate immune responses through nuclear factor-κB (NF-κB), mitogen-activated protein kinase (MAPK), and Caspase-1 pathways. While the role of NOD2 in inflammation outside the central nervous system (CNS) is well-established, especially in the gastrointestinal system, its expression and function in the brain remain poorly defined. Previous genetic studies suggest a link between NOD2 and neurological and psychiatric conditions, including stroke, Parkinson’s disease, and schizophrenia. However, information regarding NOD2 expression, localization, and function in the CNS is limited. In this work, we investigated NOD2 expression, localization, and regulation …

"I'M Not Having Fun Anymore": A Qualitative Analysis Of Gender And Harassment In Bars And Clubs, Phoebe Marie Jackson

Dissertations

Sexual harassment, while often spoken about in hushed tones or ignored altogether, happens frequently and often loudly. 66 percent of women who have experienced sexual harassment report that the harassment took place in a public space, such as work, school, or on the street (Kearl, 2018). Harassment is not discreet, but rather normalized, and those who experience it are expected to brush it off or take it in their stride. However, such harassment and subsequent dehumanization has a deteriorating effect on the mental well-being of those affected (Graham et. al., 2016). This study aims to hone in on the effect …

Systematic Review Examining How Black Youth In The United States Cope With Stressful And Traumatic Experiences, Marcus Aaron Flax

Dissertations

Coping is an important behavioral skillset that youth use to emotionally regulate after experiencing stress or trauma. Research has repeatedly highlighted the stressors that Black youth experience, often finding that Black youth face higher levels of stress and trauma than their White peers. However, there has been a lack of research in understanding how Black youth cope with these higher levels of stress. This systematic review includes 72 studies (N = 16,205 participants) examining the frequency and effectiveness of coping strategies used by Black youth in response to a trauma or stressor, along with the associations between utilized coping strategies …