Digital Commons Network^™

The Role Of Manganese In Streptococcus Sanguinis, Tanya M. Puccio

Theses and Dissertations

Streptococcus sanguinis is primarily associated with oral health as a commensal bacterium. As an opportunistic pathogen, S. sanguinis is capable of colonizing heart valve vegetations, leading to the disease infective endocarditis. Previous studies from our lab have identified the high-affinity manganese transporter SsaACB as important for endocarditis virulence. The impact that manganese depletion has on S. sanguinis had never been evaluated and a secondary manganese transporter has not been identified. Thus, we employed the use of a fermentor to control large-scale growth over time and depleted manganese in an ΔssaACB mutant using a metal chelator, EDTA. The changes in …

Development Of An Anatomically And Electrically Conductive Brain Phantom For Transcranial Magnetic Stimulation, Hamzah A. Magsood

Theses and Dissertations

Transcranial Magnetic Stimulation (TMS) is a non-invasive technique for diagnostics, prognostic, and treatments of various neurological diseases. However, the lack of anatomically realistic brain phantoms has made the experimental verification of stimulation strength in the form of induced electric fields/voltages in the brain tissues an impediment to developing new TMS coils, stimulators, and treatment protocols. There are significant technological, safety, and ethical limitations to test the potential TMS treatment procedures or develop enhancements and refine them on humans or animals. This work aims to bridge the gap by introducing and developing an innovative manufacturing and fabrications process to produce a …

Assessing The Role Of Planar Cell Polarity Protein Ptk7 In Axon Pathfinding Of Spinal Commissural Neurons, Joseph Paul Miano

Theses and Dissertations

Axon pathfinding is a fundamental step that establishes the vast networks of the nervous system. Understanding this process is important because disruptions to these neural networks can impair quality of life. During axon pathfinding, an axon’s growth cone comes in contact with a variety of secreted chemotropic signaling cues that control growth cone behavior through activation of signal transduction pathways which cause changes to the cytoskeleton. One such pathway is the Planar Cell Polarity (PCP) signal transduction pathway that responds to gradients of non-canonical Wnt ligands. PCP has a well-known role in axon pathfinding, including axon pathfinding in the spinal …

Development Of A Single Use Device Intended To Wash Blood Clot Debris From A Stent Retriever In The Operating Room, Shane Diller

Theses and Dissertations

Ischemic stroke is a life-threatening condition that requires immediate surgical intervention to remove the blood clot that is lodged in the blood vessels of the brain. Mechanical thrombectomy, performed by an endovascular surgeon, involves inserting a stent retriever, which deploys distally and attempts to capture the clot when dragged backwards. A complication prevalent in 50% - 67% of cases is that the blood clot is only partially removed and clings to the mesh framework of the stent. The operating surgeon must either clean the debris from the stent retriever, to be reinserted or throw the stent retriever away and open …

Changing Landscapes: Perspectives Of Young African American Women Of Population-Wide Testing For Hereditary Breast Cancer Mutations, Alesha Henderson

Theses and Dissertations

Young African American women continue to die from breast cancer at higher rates than White women. In an effort to promote breast cancer prevention, population-wide testing (PWT) for all women in the U.S. starting at age 30 is a potential future initiative that is garnering a lot of attention. However, African American women currently utilize genetic testing for hereditary breast cancer at lower rates than White women. Therefore, if young African American women are not prioritized in a future roll out of PWT, then existing breast cancer and genetic testing disparities will likely continue to widen. The purpose of this …

Belowground Characteristics Of Dominant Coastal Dune Grasses And Potential Community-Level Effects On Coastal Erosion, Shannon L. Walker

Theses and Dissertations

Natural dunes arise out of complex relationships between ecological, hydrological, and geological processes and are important for reducing erosion along coastlines. Aboveground structures of coastal dune grasses are known to impact erosional dynamics, and recent studies have shown that belowground structures—such as roots, rhizomes, and belowground stems— may be important in erosional resistance. My objectives were to 1) characterize above- and belowground characteristics of prominent dune grasses and 2) combine these data with functional group abundances and distribution to evaluate community effects on two adjacent locations of distinctive morphology and erosional characteristics and their response to storm disturbance. Whole plant …

Development Of Supported Pd-Based Catalysts For Carbon-Carbon Cross-Coupling And Oxidation Reactions, Mrinmoy Das

Theses and Dissertations

Heterogeneous catalysts are a crucial part of chemistry used for various chemical synthesis stages, pharmaceutical, and environmental applications. The use of nanoparticles or rather nanocatalysts enhances the heterogeneous catalytic applications. Both chemical and physical methods can be used to synthesize nanocatalysts. Chemical synthesis methods require comparatively fewer instruments and can easily synthesize a large amount of nanocatalysts. Nevertheless, chemical synthesis methods require reducing agents and solvents that can be toxic or harmful materials. They often need harsh reaction conditions as well, like high temperature and pressure. On the other hand, physical synthesis methods often require complex instrument setup, but their …

Ndrg1 And Myelin-Related Disease: Alcoholism And Chemotherapy-Induced Neuropathy, Guy Harris

Theses and Dissertations

Alcohol use disorder (AUD) is a prevalent neuropsychiatric disease with profound health, social, and economic consequences. With an estimated 50% heritability, identifying genes that engender risk and contribute to the underlying neurobiological mechanisms represents an important first step in developing effective treatments. Gene expression studies are an important source of candidate genes for studying AUD, providing windows into the molecular machinery engaged by the brain in response to ethanol. Our laboratory has implicated N-myc down-regulated gene 1 (Ndrg1) as a potential candidate gene that modulates ethanol-induced changes in myelin-related gene expression and acute sensitivity to ethanol. Analysis of …

Characterizing A20 Function In Periodontal Tissue Homeostasis, Erin Mooney

Theses and Dissertations

The regulation of inflammatory signaling pathways is critical for proper innate immune responses to pathogens as well as the prevention of chronic inflammation. Ubiquitination, a covalent posttranslational modification, has been identified as a key regulator of multiple signaling cascades, including nuclear factor (NF)-κB. A20 (also known as TNF alpha induced protein 3 or TNFAIP3) has emerged as critical ubiquitin-editing enzyme that functions as an endogenous regulator of inflammation through termination of NF-κB activation as part of a negative feedback loop. Through its function in a plethora of biological processes, aberrant expression and/or function of A20 has been implicated in gastrointestinal, …

Transcriptomic Profiling Of Postmortem Prefrontal Cortex And Nucleus Accumbens From Chronic Alcohol Abusers., Eric S. Vornholt

Theses and Dissertations

Alcohol use disorder (AUD) is a debilitating psychiatric illness that develops from a combination of genetic and environmental factors. While it is well documented that AUD is heritable, the shift from recreational alcohol use to abuse/dependence is poorly understood. In this dissertation, using postmortem brain tissue from individuals with alcohol dependence (AD), we profiled the genome-wide expression of circular RNA (circRNA), microRNA (miRNA), and messenger RNA (mRNA) to better understand the impact of gene expression on the development of AUD. To achieve this, we performed two independent studies that explore transcriptome differences between AD cases and controls. The first of …

Culturally-Relevant Factors That Influence Healthy Eating Among African American College Students, Danyel Smith

Theses and Dissertations

Obesity is a national epidemic in the US, disproportionately affecting African Americans, such that the obesity prevalence in African Americans (49.6%) surpassed the national prevalence (42.4%) in 2018. Those same disparities exist at the collegiate level, such that 27.4% of a sample of African Americans college students had obesity, surpassing the national prevalence of obesity (12.1%) in 2018. Diet, an important driver of obesity, is influenced by several psychological, social, and environmental factors. However, cultural factors influencing diet are understudied among African American college students. The overarching goal of the current study was to identify culturally-relevant factors that promote healthy …

The Origin And Evolution Of Flower Characters In Angiosperms With A Case Study On The Genetic Basis Of Zygomorphic Corolla Development In Bee And Hummingbird Pollinated Species Of Schizanthus (Solanaceae), Ghadeer Bukhari

Theses and Dissertations

This Ph.D. dissertation investigates two main projects separated into two chapters, one for each. The first chapter explores the evolution of flowering plants (angiosperms), a macro-scale study. The second project is on a micro-scale that focus on exploring the genes that regulate the similarities and the differences of flower morphology reflecting their different pollination syndromes in two species of Schizanthus (Solanaceae), i.e., S. pinnatus, a bee-pollinated flower, and S. grahamii, a hummingbird- pollinated flower.

In the first chapter, I used floral diagrams to study the origin and the evolution of floral traits in angiosperms, a new set of morphological data …

Discerning The Spectroscopic Properties And Chemical Reactivity Of Bioinspired Metallocomplexes, Ashley K. Forney

Theses and Dissertations

In Nature, metalloenzymes catalyze a variety of thermodynamically demanding reactions with remarkable performance under mild, physiological conditions. This innate ability is a driving force for the development of nature inspired, synthetic analogues that are robust and can catalyze a variety of organic transformations. This work involves the successful syntheses of four coordinate, bioinspired complexes, [M^II(n-DOB)] (M = Ni, Co, and Cu; n = 12 and 13), which have been characterized by NMR, ESI-MS, UV/Vis, EPR, and CV. Spectroscopic evidence presents the generation of reactive metal-(di)oxygen species that display amphoteric reaction behavior, making these rarities among inorganic oxidants. These …

Profiles Of Adjustment Among Children In Institutional Care In Ghana: Predictors Of Positive Functioning, Anna W. Wright

Theses and Dissertations

Worldwide, approximately 2-8 million children reside in institutional care, which can lead to developmental setbacks. Given the need for institutional care persists, it is important to continue investigating which improvements can be made to provide optimal care. The current mixed-methods study included participants from Accra, Ghana. Study 1 involved cluster analyses to determine patterns of adjustment for 100 children in institutional care (CIC) (M age = 13.31 years, SD = 3.14; 40% female) and 100 children in families (CIF) (M age = 13.37 years, SD = 3.08; 40% female) across several domains. ANOVA was used to evaluate whether …

Mother Is How I Got Down Pat, Kyrae Dawaun

Theses and Dissertations

This essay gathers concepts of matriarchal studies, theatre and hospitality in thinking beyond the contemporary venue of painting. Recognizing the limits of fine arts, as it is today, a product of a patriarchal, capitalistic societal structure, in its service to an inclusive, public sphere, my work is insistent on the value of installation. Accessibility to space (the art space), language, and the right to politics are goals inspiring the evolved features in my studio practice. The use of word is central in my study of our human behaviors as they can be best modeled according to the appreciation of mother(ing). …

Detection Of Biomolecules Via Ocp Measurements Using Npg Electrodes, Borkat Ullah

Theses and Dissertations

In sensing application nanoporous gold (NPG) has attracted much attention. NPG is prepared by dealloying Au:Ag alloys. Characterization was done using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and cyclic voltammetry (CV). In this work, the open circuit potential (OCP) of ferricyanide, cysteine, uric acid, and ascorbic acid was measured in phosphate buffer solution (PBS) and biofouling solution containing bovine serum albumin (BSA) at pH 7.4. OCP measurement has been hindered due to biofouling and surface passivation on the metal electrodes. By the use of the NPG electrodes, electrochemical activity can be maintained. From the OCP measurement of cysteine, …

Port To World, Samuel M. Brown

Theses and Dissertations

Among those that are ill for long periods, there is often a mistrust created not only in one’s own body but in the institution that promises a cure to the malady. Often this stems naturally from the dogma of the institution paired with one’s desire for wellness, for the institution's goals are many besides the overall health of the patient. Even when a patient is cured of an ailment, this is often just the first step in the actual healing process. The body can quickly change, and the mind takes time to catch up with the body's condition. My work …

Paul By Paul By Paul, Paul Finch

Theses and Dissertations

In 2020 flamboyant fashion is associated with queer performativity. Psychologist Alan Downs and queer theorist madison moore understand this to be a response to a culture that is hostile to sexual behaviour and gender expression that falls outside a rigid binary. I study the history of flamboyant aesthetics and camp sensibilities from an intersectional perspective, and locate designers and artists who have produced clothes in ways that materialize the political implications of fashion. As a studio-based artist, I employ traditional sewing techniques, digital technologies, and performance to create clothes and new media works that demonstrate a circular understanding of time, …

The Heat Is On: Comparison Of Thermoregulatory Behavior In Parasitised Versus Unparasitized Caterpillars Of The Tobacco Hornworm, Manduca Sexta (L.) [Lepidoptera: Sphingidae], Jessica M. Johnston

Theses and Dissertations

Insect thermoregulatory research has demonstrated evidence of variation occurring within and among species with respect to infection, pathogens, and parasitism, but few studies have examined differences in thermoregulatory behavior in a host-parasite system with a coevolved symbiotic virus. I investigated the role of parasitism by Cotesia congregata (Say) (Hymenoptera: Braconidae) on the thermoregulatory behavior of Manduca sexta (L.) (Lepidoptera: Sphingidae) using an experimental design in a thermal gradient chamber and a complementary observational field study on wild M. sexta collected from tobacco farms. Parasitism and larval age were not found to have a significant effect on the preferred body temperature …

See As One, Min Haeng Kang

Theses and Dissertations

Everything that exists in the world is made from “nature.” Humans who initially coexisted with nature began to distinguish themselves from what is human and what is not. Unlike past systems that used to reuse all materials, Society so far has focused on maximizing economic profits along with advancing technology. As a result, the nature of the earth is being irrevocably destroyed, and I think the basis for this lies in the distinctions made between the human and the non-human.

I am always seeking to be in a state where I do not have an atman, like the Buddhist concept …

Novel Strategies To Overcome Carboplatin Resistance In Triple Negative Breast Cancer Using Patient Derived Xenografts, Mohammad A. Al Zubi

Theses and Dissertations

Triple-negative breast cancer (TNBC) patients have a poor prognosis and rely on chemotherapeutic treatment as standard of care. Often, they develop chemotherapy resistance, which leaves them without more therapeutic options, like targeted therapy. New models have been developed to test targeted inhibitors in human tumors, and they are known as patient-derived xenografts (PDX). These tumors are obtained from patients, then established and maintained in mice where they areused for tumor studies. In this work, we characterized 14 PDXs for their primary tumor growth rate and investigated metastatic propensity using spontaneous and experiment metastasis models. We utilized RNA-sequencing to characterize contributions …

Analysis Of Stigmatic Content In State Mental Health Legislative Proposals, David L. Conley

Theses and Dissertations

Despite the proven effectiveness of mental health interventions, services remain limited across the country. Social workers have repeatedly advocated for increased funding, but mental healthcare gaps persist. Disparities could be addressed through the policy process, but critical proposals often do not pass. One of the biggest barriers is the concept of stigma, which could extend into legislatures and influence mental health-related policy outcomes as a form of structural stigma. Factors that influence legislator voting behavior are found in the literature, but studies have not explicitly focused on structural stigma or mental health-specific policy outcomes. Thus, the present study aimed to …

The Role Of Interleukin-18 In Myocardial Ischemia/Reperfusion, Yogesh Dhakal

Theses and Dissertations

Acute Myocardial Infarction (AMI) is one of the leading causes of morbidity for cardiovascular diseases (CVDs) in the western world. While mortality rates for AMI has reduced in the last 20 years due to advancements in clinical interventions, patients who have an AMI are significantly more likely to develop heart failure (HF) in the following years. Reperfusion of the ischemic tissue is a necessary procedure to restore blood delivery to cardiomyocytes, minimize myocardial dysfunction, and reduce infarct size. Still, the step of reperfusion itself induces myocardial damage in a phenomenon known as reperfusion injury. Considering that the degree of myocardial …

Can School Be A Source Of Trauma? Assessing Academic Traumatic Stress As A Mechanism Underlying The Health Outcomes Of Black Undergraduate Students, Ebony A. Lambert

Theses and Dissertations

Research examining Black students’ school experiences demonstrates that exposure to oppressive power dynamics in schools may lead to adverse physiological and psychological consequences. Recent conceptualizations in public discourse further posit that traumatic educational experiences, operationalized here as academic trauma or the cumulative toll of adverse and oppressive experiences in academic settings, may influence Black students’ wellbeing even after they have graduated. However, academic trauma has yet to be investigated empirically, and the health contributions of such educational harm remain unstudied. Moreover, little is known about how culturally-relevant personal characteristics (e.g., emotion regulation strategies) influence Black students’ reactivity to academic trauma. …

Taxa Specific Responses To Flooding Shape Patterns Of Abundance In A River Rock Pool Metacommunity, Charles R. Stunkle

Theses and Dissertations

Connectivity and habitat area are important landscape characteristics that drive patterns of abundance and diversity across scales. However, responses to connectivity and patch size are dependent on species traits. Riverine landscapes are highly dynamic both spatially and temporally with hydrologic connectivity being a major driver of abundance and diversity. Here we modeled densities of the Virginia river snail and skimmer dragonfly nymphys, two taxa with differences in their dispersal abilities and life histories, as a function of flooding, patch area, and season in over 300 riverine rock pools. We found key differences in how each taxon responded to these predictors …

Anti-Tumor Functions Of Sphingosine Kinase 1 And Sphingosine Kinase 2 In Breast Cancer Development, Melissa A. Maczis

Theses and Dissertations

Bioactive sphingolipid metabolite sphingosine-1‐phosphate (S1P) circulating levels have been implicated in breast cancer (BC) progression. BCs usually respond to 17β-Estradiol (E2) through canonical receptor ERα66 for genomic effects, however, E2 also triggers rapid, non-genomic responses. E2 has been shown to activate sphingosine kinase 1 (SphK1), increasing S1P for S1P receptors signaling important for BC. The E2 receptor activating SphK1 has not been identified. We demonstrate triple negative BC cells, expressing only novel ERα splice variant ERα36, E2-induced SphK1 activation for S1P secretion. Tamoxifen, first-line BC endocrine therapy, an ERα66 antagonist but ERα36 agonist, activates SphK1 and increases S1P secretion in …

Focal Augmentation Of Somatostatin Interneuron Function And Subsequent Circuit Effects In Developmentally Malformed, Epileptogenic Cortex, Nicole Ekanem

Theses and Dissertations

Drug-resistant epilepsy (DRE) is a common clinical sequela of developmental cortical malformations such as polymicrogyria. Unfortunately, much remains unknown about the aberrant GABA-mediated circuit alterations that underlie DRE's onset and persistence in this context. To address this knowledge gap, we utilized the transcranial freeze lesion model in optogenetic mice lines (Somatostatin (SST)-Cre or Parvalbumin (PV)-Cre x floxed channelrhodopsin-2) to dissect features of the SST, PV, and pyramidal neuron microcircuit that are potentially associated with DRE. Investigations took place within developmental microgyria’s known pathological substrate, the adjoined and epileptogenic paramicrogyral region (PMR). As well, microcircuit relationships within the previously unexplored range …

Solid Phase Extraction And High-Precision Mass Spectrometry Analysis Methods For Crassostrea Virginica Metabolome, Alyssa Darling

Theses and Dissertations

Metabolomics is the rapidly-growing field which focuses on the endpoints of biological processes, and has the capability to provide a snapshot of an organisms’ interaction with their environment on a molecular scale. The objective of the experiment herein was to develop a standard metabolic extraction technique coupled with ultrahigh-precision analytical tools to build a global metabolic pathway of the keystone species Crassostrea virginica. To achieve this, C. virginica whole-body samples were extracted using acetonitrile and methanol, then split into a dehydrated group and a diluted group. Following reversed-phase solid phase extraction (RP-SPE) of both groups, metabolites were identified using …

Spag17 Is Important For Protein Trafficking In Mammalian Spermiogenesis, Virali Bhagat

Theses and Dissertations

Spermiogenesis is the process through which undifferentiated germ cells develop into mature spermatozoa. While spermiogenesis is a very well-regulated process, the protein-protein interactions regulating it remain poorly understood. A knockout (KO) mouse for the ciliary protein SPAG17 was generated by our lab. Loss of SPAG17 has been shown to disrupt the transport of proteins important for acrosome biogenesis and manchette functions. With this information, we hypothesized that SPAG17 plays an essential role in protein trafficking during mammalian spermiogenesis. To further investigate this, immunofluorescence (IF) studies were performed in germ cells collected from both WT and SPAG17 KO mice to visualize …

Prediction Of The Vaginal Microbiome Using Urine Samples, Christopher R. Diachok

Theses and Dissertations

The vaginal microbiome is associated with women’s health, including but not limited to the pathogenesis of bacterial vaginosis, adverse pregnancy outcomes including preterm birth and sexually transmitted infections. However, there has been very limited research on the urinary microbiome and its relationship to the vaginal microbiome. We sought to predict the vaginal microbiome profile using clean catch urine samples from the same person. Here, paired vaginal and urine samples were collected and sequenced by 16S ribosomal RNA sequencing. Alpha and beta diversity analysis showed that there was no significant difference between the paired vaginal and urine microbiomes. In fact, a …