Digital Commons Network^™

Plant Trait Effects On Tidal Wetland Methane Emission, Adam M. Dunn

Theses and Dissertations

High rates of carbon (C) sequestration exhibited by coastal wetlands is an important natural climate solution to global environmental change. At the same time, however, wetlands are the largest natural source of methane (CH₄) to Earth’s atmosphere, a potent greenhouse gas that influences the global climate. Wetland CH₄ emissions display high degrees of uncertainty in accounting for spatial and temporal variations in emissions due to the complex interactions between biotic and abiotic factors that influence methane production and transport, in addition to simultaneous influences from climate-driven effects on wetlands such as rapid sea level rise and increased …

Practice Elements Delivered By Teachers To Support Children Who Display Challenging Behaviors In Business-As-Usual Early Childhood Settings, Navneet Kaur

Theses and Dissertations

Approximately 15-25% of children ages 3 to 5 years in early childhood settings display chronic challenging behaviors that increase their risk for developing an emotional and behavioral disorder. The early onset of emotional and behavioral disorders has long-term negative implications for these children. Therefore, it is vital to address these problems early on. One approach is through teacher-delivered practices (i.e., specific strategies, such as praise) and programs (i.e., manualized interventions that contain a collection of practices) in the classroom. Some practices and programs have shown positive outcomes for children. However, when practices and programs do not outperform business-as-usual group (BAU), …

Trans* Streamers On Twitch.Tv: The Intersections Of Gender And Digital Labor, R. Lawson

Theses and Dissertations

Twitch.tv is a live entertainment platform where individuals live stream events, including playing video games, playing board and tabletop games, creating art, and more. Twitch has a diverse base of streamers, but Twitch has just begun. The most common approach has focused on cisgender, heterosexual white men in the cases where it has been studied. Though these streamers should be studied in sociology, this focus leaves out the experiences of both cis women and Trans* streamers. This research proposal tries to situate the relationship of Trans* streamers with both the platform and their audience, seeing if these relationships affect their …

The Hepatic Immunological Pattern Shaped By Dominant-Subdominant Cellular Interactions Creates A Collective Function Beyond The Function Of Each Cellular Constituent To Orchestrate Progression Of Hepatocellular Carcinoma, Nicholas J. Koelsch

Theses and Dissertations

Abundance of data on the role of inflammatory immune responses in the progression or inhibition of hepatocellular carcinoma (HCC) has failed to offer a curative immunotherapy for HCC. This is largely because of taking reductionist approaches and missing the collective function of the hepatic immune system by focusing on specific immune cell types. To this end, we propose that focusing on the dominant-subdominant patterns of the immune cells would allow understanding of the mechanism by which a collective immune function emerges. To identify the collective immune function through a systems immunology perspective, we performed high-throughput analysis of snRNAseq data collected …

Interiorization And Localization: An Analysis Of Immigration Enforcement In Local Contexts, Manuel N. Leiva

Theses and Dissertations

Immigration and Customs Enforcement (ICE) is a federal agency that plays a large role in surveilling, apprehending, detaining, incarcerating, and deporting undocumented immigrants in the United States. Due to constraints on the number of ICE’s available personnel and resources, the agency relies on deputizing, or devolving to local law enforcement agencies the authority to enforce federal immigration policies. Prior to the 1990s, the enforcement of policies directed at controlling flows of undocumented immigrants was generally under the purview of federal law enforcement agencies and administrators, not state or local ones. The attacks on September, 11^th 2001 represented a flashpoint, …

Model Based Systems Engineering Approaches To Chemicals And Materials Manufacturing, Quang Le

Theses and Dissertations

Model-based systems engineering (MBSE) is part of a long-term trend toward model-centric approaches adopted by many engineering disciplines. This work establishes the need for an MBSE approach by reviewing the importance, complexity, and vulnerability of the U.S. chemical supply chains. The origins, work processes, modeling approaches, and supporting tools of the systems engineering discipline (SE) are discussed, along with the limitations of the current Process Systems Engineering (PSE) framework. The case is made for MBSE as a more generalizable and robust approach. Systems modeling strategies for MBSE are introduced, as well as a novel MBSE method that supports the automation …

Food Deserts And Pediatric Oral Health Status In An Under-Resourced Urban Community, Jessica T. Mcauliffe

Theses and Dissertations

Purpose: The aim of this analysis of survey data was to assess the influence of living within a food desert as a predictor of oral health problems among children of East Henrico County, Virginia.

Methods: Survey participants were recruited and questionnaires applied online. Residing in a food desert, using access to affordable produce as a proxy value, was the independent variable, while self- reported assessment of the child’s oral health status was the primary outcome variable. Analyses controlled for other indirect factors of pediatric oral health. Logistic regression was used to model the association between the self-reported access to healthy …

Investigation Of Sneathia Vaginalis And The Host Antibody Response To S. Vaginalis Pore-Forming Toxin, Cpta, In Vivo, Zion T. Mccoy

Theses and Dissertations

Sneathia vaginalis, formerly Sneathia amnii, is a gram-negative vaginal species that is associated with pregnancy complications including preterm birth. The only virulence factor of S. vaginalis that has been characterized is the cytopathogenic toxin, component A (CptA), a pore-forming toxin that lyses human red blood cells and human epithelial cells and plays a role in traversal of the bacteria through fetal membranes. The overarching goal of this work was to examine the host immune response to CptA. To investigate the immune response to CptA, levels of anti-CptA IgM, IgA, and IgG in human mid-vaginal swab samples obtained during …

Treponema Denticola Synthesizes C-Di-Amp And Encodes The Cdaa-Type Diadenylate Cyclase Cdaa, Claire R. O'Brien

Theses and Dissertations

Periodontitis is a form of oral disease characterized by dysbiosis of the oral microbiome, leading to inflammation, bone resorption, and in severe cases, entire tooth loss, affecting 42% of adults in the US. One of the bacteria most associated with periodontal disease progression is Treponema denticola (Td), an oral spirochete which inhabits the mouth in small quantities during health but which can dominate the biofilms that form during periodontal disease. The ability of Td to survive in a disease environment and contribute to the progression of disease requires the use of robust signaling networks. Analysis of Td cultures …

Role Of Histone Deacetylase (Hdac) In Epithelial To Mesenchymal Transition (Emt) In A Human Cholangiocyte Model Of Ischemic Cholangiopathy, Priyanshi Pragnesh Parikh

Theses and Dissertations

Organ transplants are a vital intervention for many diseases that result in end stage organ failure. Currently, the donation pool is not meeting the demands of the transplant list. Expanding this pool to include donation after cardiac death (DCD) is highly sought-after. However, the use of DCD livers can lead to increased odds of graft failure and ischemic cholangiopathy. The loss of epithelialization and fibrosis that occurs during ischemic cholangiopathy is characteristic of these cells undergoing epithelial-to-mesenchymal transition (EMT). The biological changes the cell experiences enhance migratory capacity, invasiveness, and increased resistance to apoptosis. Our earlier studies have shown differential …

Motivations Of Adult Patients Seeking Orthodontic Retreatment, Scott V. Philips

Theses and Dissertations

Objective: The aims of this study were (1) to compare the reasons adult patients seek orthodontic first-time treatment to the reasons adult patients seek orthodontic retreatment, and (2) to compare the concerns, motivations, and satisfaction levels of adult patients seeking orthodontic retreatment across the different previous treatment provider types of orthodontist, general dentist, and Direct-to-Consumer company.

Methods: At their initial orthodontic visit, adult patients (N=108) were invited to participate in the digital survey (REDCap) study. Subjects were recruited from the graduate orthodontics clinic at Virginia Commonwealth University and seven private orthodontic practices across the United States. Visual Analogue Scales were …

Characterization And Investigation Of Cold Atmospheric Plasma And Its Effects On Cancer Cell Biology, Thomas M. Ritrosky

Theses and Dissertations

Modern cancer treatment uses radiation therapy in over 50% of patient cases. It is an e↵ective way of treating tumors because the mechanisms of cell killing are well known through the damage that ionizing radiation does to DNA. The amount of radiation can be tracked through measuring the dose of the clinical photon or electron beam used. However, there are limitations in the usage of radiation therapy, for example, a tumor can create hypoxic areas that become radioresistant leading to complete ine↵ectiveness of further radiation treatment. This project looks into the application of cold atmospheric plasma as an adjuvant therapy …

To, From: Of Time, Of Distance, Of Body And Mind, Fanxi Sun

Theses and Dissertations

This paper introduces the concepts, theories, and techniques associated with my thesis project “To, From.” The paper consists of three parts: Time as Structure, Distance as Premise, and Body and Mind. Each chapter is written in a mixture of personal narration and a general introduction to materials that are directly or implicatively relevant and important to the creation of my project. In this experimental narrative comprises film screening and live performance with multi-channel sound, I tell a story of non-story. Words and the exchange of words, movements and non- movements, objects that are being handled and subjects that are handling... …

The Impact Of A Parent-Only Pediatric Obesity Intervention Program On Quality Of Life In Racially Diverse Children, Taylor Vashro

Theses and Dissertations

Pediatric obesity has been associated with significant decrements in pediatric quality of life (QOL) comparable with severe pediatric diseases such as cancer. Parenting interventions have yielded health benefits for children with obesity; however, few studies have investigated the impact of parent-focused interventions on QOL in children with overweight and obesity. This study investigated the impact of a 6-week intensive parenting intervention program on the QOL of 5-12 year old, predominantly Black children with overweight and obesity. Parents were randomized into either the parenting intervention (NOURISH+) or a control group, and QOL, as well as variables related to child and parenting …

Epithelial Membrane Protein 3 (Emp3b) Is A Novel Regulator Of Sympathetic Nervous System Development In Zebrafish., Jessica M. White

Theses and Dissertations

Notable progress has been made in understanding the development of the neural crest (NC). Neural crest cells (NCCs) can be divided into 4-5 subpopulations. A major lineage among trunk NC derivatives are sympathoadrenal (SA) cells, which give rise to the sympathetic nervous system (SNS). Trunk NCCs follow a ventromedial migration pathway where signals derived from the dorsal aorta instruct migrating NCCs to a SA cell fate. Defects in NC development can result in syndromes known as neurocristopathies. Neuroblastoma is one of the most common forms of pediatric cancer affecting nearly 800 infants each year in the United States (Takita et …

Attitudes And Beliefs Of Cannabis Use During Pregnancy: Hashing Out The Impact Of Location And Legality, Anna Wiese

Theses and Dissertations

As more states authorize the use of cannabis for medical and recreational purposes, rates of prenatal cannabis use are on the rise. Yet research on perceptions of prenatal cannabis use has been limited, and the existing research lacks reliable, quantitative measures. In response, researchers in Denver developed the Perceptions of Prenatal Cannabis Use (PPCU) survey, a 16-item measure designed to assess perceived risks and benefits of prenatal cannabis use. The present study analyzed PPCU survey data administered at three different recruitment sites (Denver, CO; Pittsburgh, PA; and Richmond, VA). The present study examined women’s perceptions of the risks and benefits …

Profiles Of Family Functioning In Pediatric Hematology-Oncology Patients: Longitudinal Associations With Child Well-Being, Sydney Sumrall

Theses and Dissertations

This study aims to assess 1) patterns of family functioning and 2) longitudinal associations between family functioning patterns and well-being in a vulnerable cohort of children with chronic illness. Caregivers of hematology (16.4%) and oncology (83.6%) patients ages 7-20 (N=55; M_age = 13.3 [SD = 2.7]; 52.7% female; 45.5% non-Latinx White, 38.2% Black or African American, 12.7% Latinx, 1.8% Asian, and 1.8% multi-racial,) reported on family functioning via the Family Assessment Device. Cluster analyses identified three mutually exclusive clusters: one high adaptive group, one moderate adaptive group, and one maladaptive group. Group membership was not significantly …

Random Acts Of Stem: A Systematic Review Of Local K-12 School Division Stem Experiences In Virginia, Caro H. Medawar

Theses and Dissertations

The initial purpose of the study was to determine whether the school divisions in Virginia have definitions of STEM education. For the divisions that have described STEM education, the following valuation was based on the precise STEM education definition each has implemented. The population for the study included all 132 school divisions in This mixed-methods study investigated the implementation of STEM programs in Virginia K-12 schools. Data were collected through two avenues: publicly available online resources from school divisions and interviews with STEM leaders in the Virginia educational system. Data analysis on these two sources yielded five themes: (a) existence …

Frewayni's Garden: Preserving Tigrayan Culture During A Period Of Ethnocide, Gabrielle F. Tesfaye

Theses and Dissertations

The recent and ongoing genocidal war in Tigray, Ethiopia, has witnessed the destruction and looting of countless historical religious sites, ancient manuscripts, and artifacts, leaving Tigray’s remaining cultural heritage extremely vulnerable. Such cultural loss erases a shared understanding across generations, robbing them of their history and identity. My work contributes to the safeguarding of Tigray’s cultural heritage and collective memory, informed by literature on cultural preservation efforts in post-war societies, and a series of interviews with Tigrayans in the diaspora and in Ethiopia.

The outcome of this thesis is embodied in a series of distinct jebenas, traditional Tigrayan clay coffee …

The Lived Experience Of Postpartum Sleep For Black And White Women, Ashley R. Macpherson

Theses and Dissertations

This qualitative study utilized a phenomenological research approach (van Manen, 1990), and intersectional feminist lens (Collins, 2000; Crenshaw ,1989; hooks, 2000), to uncover the lived experience of sleep in the postpartum period. Participants were 10 mothers who were less than 12 months postpartum. Data collection consisted of in-depth interviews. Data analysis procedures followed recommendations by van Manen (1990, 1997). In order to increase the trustworthiness and rigor of the study, the researcher engaged in reflexive journaling, member checking, and peer debriefing. The results were organized into six themes; 1) the importance of the sleep environment, 2) anxiety and hypervigilance, …

Physical Activity In Adolescents With And Without Adhd: Longitudinal Associations With Sleep, Adhd, And Internalizing Symptoms, Caroline N. Cusick Lowman

Theses and Dissertations

Adolescents with Attention-Deficit/Hyperactivity Disorder (ADHD) are at risk for developing clinically significant sleep problems and comorbid internalizing symptoms. Physical activity (PA) has significant positive associations with a variety of health outcomes, including sleep and aspects of mental health. As such, the US Department of Health and Human Services recommends adolescents receive at least 60 minutes of moderate-to-vigorous PA (MVPA) per day. However, it is unknown whether adolescents with ADHD have different patterns of physical activity compared to their peers. Importantly, it may be that PA can serve as a buffer between ADHD symptoms and development of comorbid difficulties with sleep …

The Influence Of The Covid-19 Pandemic On Rural Virginia Secondary Teachers’ Self-Efficacy, Sherol L. Southerland

Theses and Dissertations

The COVID-19 pandemic has presented unique challenges for PK-12 education and exposed educators’ skill deficits. Teachers had to learn new approaches to doing their jobs while navigating the mental, emotional, spiritual, and financial impact of the pandemic on their personal lives. This undertaking was even more demanding for rural school divisions, which tend to lack the resources (e.g., personnel, technology, financial) that suburban and urban school divisions have. Schools reopened in fall 2020 offering fully remote, fully in-person, and hybrid modalities, however, there was no going back to teaching as it was before the pandemic. The present study sought to …

The Impact Of Hiv-1 Tat And Morphine On Spatial Distribution Of Drugs In The Brain., Austin M. Jones

Theses and Dissertations

Despite combination antiretroviral therapy effectively suppressing HIV within the periphery, the central nervous system (CNS) remains affected by the virus. Approximately half of people living with HIV will experience HIV-associated neurocognitive disorders (HAND) or neuroHIV. Concurrent opioid use exacerbates neuroHIV by promoting neuroinflammation, viral replication, and potentially altering the antiretroviral concentrations within the brain.

Using a transgenic mouse that expresses the HIV-1 Tat protein, we examined the effects of Tat and morphine on antiretroviral accumulation and distribution and the effects of Tat on morphine accumulation within the brain using infrared matrix-assisted laser desorption electrospray ionization with mass spectrometry imaging (IR-MALDESI-MSI). …

Reassessing Replication: Addressing The Replication Crisis From A Statistical Perspective, Alicia Richards Phd

Theses and Dissertations

In 2015, Open Science Framework directly replicated 100 psychology studies and found astonishingly low replication rates. Since, researchers have suggested factors that may have influenced the low rates, including the metrics used to assess replications. The definitions used to decide whether a replication study was successful all suffer from flaws. Therefore, we propose a new metric for assessing replication that can estimate the likelihood a study successfully replicated rather than forcing a binary choice and accounts for study design limitations.

Using equivalence study techniques, we first propose a new metric to assess replication, defining a successful replication as one where …

Witnessing Community Violence And Its Consequences: Changes Across Middle School, Sarah Pittman

Theses and Dissertations

Community violence exposure is prevalent among youth residing in economically marginalized communities that have high rates of violence. Witnessing community violence has been concurrently associated with persistent adverse consequences. However, few studies have applied a developmental psychopathology framework and examined dynamic developmental processes between witnessing community violence and outcomes over time. Moreover, most prior studies have used analyses that assume that associations between witnessing violence and outcomes are the same for all adolescents, which is inconsistent with both developmental theories and theories specific to community violence exposure. The goal of this study was to apply a developmental psychopathological framework to …

Studying Gene Function In Streptococcus Sanguinis Using Rna-Sequencing Analysis, Ahmed Ismail

Theses and Dissertations

The oral cavity hosts hundreds of bacterial species, amongst them are the Streptococci family. More specifically, S. sanguinis is a benign bacteria in the oral cavity to protect the tooth surface from S. mutans. which is a pathogen causing dental caries. While S. sanguinis is harmless in the oral cavity, it becomes pathogenic once entering the bloodstream and causing Infective Endocarditis (IE). To further study S. sanguinis and eventually develop an effective drug to treat IE caused by S. sanguinis, a gene expression study was conducted. In order to study gene expression, RNA-sequencing was conducted, and appropriate methods to remove …

Exploration Of Dimensional Structure Of Major Psychiatric Disorders Reveals Relationship With Substance Use And Personality, Noah Berley

Theses and Dissertations

Objective: Using a mixture of statistical techniques like structural equation modeling, confirmatory, and exploratory factor analyses, we aimed to determine the genetic factor structure among Externalizing, Internalizing, and Psychotic spectrum disorders through methods that evaluate GWAS-based correlations. Additionally, a subsequent factor analysis based on the most suitable psychiatric model was conducted to understand how non-clinical behavioral traits align with this factor structure.

Methods: Publicly available GWAS summary statistics for twelve major psychiatric disorders, six substance use measures and two personality domains were incorporated into structural equation models. Using the GenomicSEM software package, GWAS-based correlations were estimated between all twelve disorders …

Grounded In Teachers’ Reality: A Collective Case Study On Middle School Teachers’ Self-Efficacy For Equity-Centered Trauma-Informed Educational Practices, Margaret Wallace

Theses and Dissertations

The current body of literature clearly demonstrates the high prevalence of student trauma and the significant impact of trauma on adolescents' well-being and academic outcomes. Middle school teachers are uniquely positioned to support adolescents experiencing trauma using trauma-informed educational practices (TIEP), however, more work is needed to understand their self-efficacy beliefs for using TIEP. Thus, the purpose of this qualitative collective case study is to explore middle-school teachers' self-efficacy (TSE) beliefs for trauma-informed educational practices particularly as they relate to centering equity, and what factors impact those beliefs. Specifically, my study asks the following research questions, (1) How do middle …

Effectiveness Of Financial Incentives In Improving Breast Cancer Screening Among Medicaid Recipients, James B. Sherwood

Theses and Dissertations

Breast cancer remains one of the leading causes of death among women. Roughly 2.4 million women are diagnosed annually with breast cancer throughout the world. Although breast cancer survival rates are favorable for the United States compared to other nations (90% 5-year survival for non-metastatic disease), it comes at a high cost. The United States spends an estimated $30 billion annually on breast cancer treatment. In addition, disparities in breast cancer survival rates also exist in the United States. Women Medicaid recipients, who are predominately minorities (60%), are more likely to die of breast cancer due to their high rates …

Genomic Comparison Of Dba/2j And C57bl/6j Strains Of Mus Musculus And Best Practice Of Genome Alignment For Bioinformatics Analyses, Dustin J. Zeliff

Theses and Dissertations

Alcohol use disorder is known to have significant genetic components that contribute to an individual’s susceptibility to the disease. Mouse models are commonly used to study the mechanisms underlying alcohol use disorder, with C57BL/6J (B6) and DBA/2J (D2) being two of the more prominently used inbred strains. Research in the Miles Laboratory has used these two strains, and genetic panels of mice derived from them, to identify potential genes associated with variance in ethanol-related behaviors using quantitative trait loci (QTL) analysis. For example, Ninein (Nin) was identified as a potential candidate gene for the anxiolytic effects of ethanol, discovered because …