Digital Commons Network^™

New Treatment Options For Concussions Using Hyperbaric Oxygen Therapy, Crystal Amundson

Theses and Graduate Projects

Background: Millions of Americans experience concussions every year. With new attention from the media looking into the long-term sequela of concussions, more research and studies are initiated to find an effective treatment. Concussions happen after an impact to the head or body that causes a pathologic disruption in normal brain function. Symptoms most commonly associated with the trauma are headaches, emotional distress, vestibular disturbances and sensitivity to light. Historically, treatment has been physical and cognitive rest.

Methods: A systematic search of PubMed was performed to identify articles pertaining to the use of hyperbaric oxygen therapy in concussions and traumatic brain …

2020 Commencement, Harding University

Commencement Programs

Program for the Harding University Commencement orignially scheduled for August 15. The ceremony was posponed until November 2020 due to the COVID-19 pandemic.

Commencement Speaker: Michael L.James

Regulation Of Yolk Microtubule Dynamics By Dachsous Cadherins, Gina Danielle Castelvecchi

Arts & Sciences Graduate Student Theses and Dissertations

The process of epiboly, or the thinning and spreading of a tissue, is a well-conserved morphogenetic process. As one of four conserved gastrulation cell movements, epiboly is important to help organize the overall body plan. Epiboly in zebrafish involves the thinning and spreading of the blastoderm originating from the animal pole to completely enclose the yolk. It is driven by a multitude of physical processes that involve the three cell types comprising the embryo: the yolk syncytial layer (YSL), enveloping layer (EVL), and deep cells. These physical aspects can be broadly described as involving cell-cell interactions through adhesion proteins, actomyosin …

Emotions And Trust Repair: An Intrapersonal And Interpersonal Approach, Jonathan Ian Lee

Arts & Sciences Graduate Student Theses and Dissertations

Trust is an important element of relationships in organizations; however, it frequently is broken and requires repair. Research has provided insight into the cognitive mechanisms underlying trust repair. Surprisingly, however—given that trust violations are often highly emotional events—the role of emotions has been overlooked. My dissertation looks at the roles that emotions play in this process, with a particular focus on anger. Drawing on trust research and theories of emotions, I identify two routes through which emotions can impact trust repair. One route is intrapersonal: felt anger leads the victim to ruminate about the trust violation, making them less receptive …

Mechanisms Of Cross-Presentation By Cdc1s, Derek James Theisen

Arts & Sciences Graduate Student Theses and Dissertations

Classical dendritic cells (cDCs) are specialized antigen presenting cells that can be divided into distinct subsets based on the types of pathogens they respond to and the type of immune response they generate. The cDC1 subset is specialized in priming CD8 T cell responses through the process of cross-presentation. During cross-presentation, exogenous protein antigens are taken up by cDC1 and presented on MHCI molecules, allowing for the priming of CD8 T cells during conditions when DCs themselves are not directly infected. The ability to cross-present in vivo is unique to cDC1, and is essential for anti-viral responses and rejection of …

Engineering Natural Competence Into The Fast-Growing Cyanobacterium Synechococcus Elongatus Utex 2973, Kristen Elizabeth Wendt

Arts & Sciences Graduate Student Theses and Dissertations

Synechococcus elongatus UTEX 2973 is the fastest growing cyanobacterium discovered to date. Using water, carbon dioxide, and light alone, this organism can double in 1.5 hours under optimal conditions. The accelerated doubling exhibited by Synechococcus 2973 makes it a prime candidate to serve as a model photoautotrophic system. However, Synechococcus 2973 lacks one highly desirable feature: it cannot undergo natural transformation. This thesis seeks to engineer this capacity into this fast-growing system in order to create an organism that is both fast growing and naturally competent. Synechococcus 2973 is a unique platform because it is >99% genetically identical to another …

A Mechanistic And Genomic Analysis Of Molluscum Contagiosum Virus Immune Evasion, Ian Benjamin Harvey

Arts & Sciences Graduate Student Theses and Dissertations

Molluscum contagiosum virus (MCV) is a common human-specific poxvirus with a proclivity forinfecting children and the immune-compromised. A characteristic MCV infection is restricted tothe epidermal layers of the skin and can persist for weeks to years in an otherwise healthyindividual. The high clinical burden of MCV is at odds with our limited knowledge regarding howit successfully evades the human immune response, which is in part due to the lack of an animalmodel or cell line to propagate the virus. Through this dissertation, we have uncovered andcharacterized a novel mechanism by which MC80, a protein encoded by MCV, downregulateshost MHC-I surface …

Genomic Analysis Of Diverse Bacterial Pathogens, Robert Potter

Arts & Sciences Graduate Student Theses and Dissertations

Bacterial pathogens have been a historical scourge for the entirety of human existence but have been significantly thwarted since the 20th century due to the development of antibiotics. However, owing to the large selection pressure of antibiotics on bacterial populations, phenotypic antibiotic resistance from the development of vertically transmitted mutations and horizontally acquired antibiotic resistance genes (ARGs) is increasing. The sum has produced multidrug resistant organisms (MDROs) which have extremely limited treatment options. Epidemiological studies have determined that carbapenem resistant Enterobacteriaceae (CRE), Acinetobacter baumannii, and vancomycin resistant Enterococcus (VRE) are some of the most problematic MDRO infections. The advent of …

Delineating The Role Of Mir-124 For The Activation Of Neuronal Program, Ya-Lin Lu

Arts & Sciences Graduate Student Theses and Dissertations

The ectopic expression of two brain-enriched microRNAs (miRNAs), miR-9/9* and miR-124 (miR-9/9*-124), can robustly and efficiently reprogram human skin fibroblasts into neurons. The miRNAs act as repressors of non-neuronal genes in fibroblasts for the induction of the neuronal program. This process is analogous to neurogenesis in vivo when the expression of miR-9/9* and miR-124 represses anti-neurogenic genes such as REST or NRSF (neuron-restrictive silencer factor/repressor element-1 silencing transcription factor). Although we have some mechanistic insights into how miR-9/9*-124 drives fate conversion by acting as negative regulators of gene expression, little remained understood of the role of miRNAs as positive regulators …

Genetic And Functional Characterization Of Novel Host Factors Regulating Virus Infection In Caenorhabditis Elegans, Luis Enrique Sandoval

Arts & Sciences Graduate Student Theses and Dissertations

Viruses infect the majority of eukaryotic life on the planet and remain a global threat to human health. These pathogens are constrained to intracellular life cycles, as they exploit and rely on host factors and machinery throughout their entire reproduction process. While many of these viral life cycle factors have been reported and studied, our knowledge in the identity and function of these factors remains incomplete and a challenge in fundamental virology and the development of antiviral therapeutics. Caenorhabditis elegans offers an innovative approach for discovering novel host factors required for virus infection in a multicellular and simple model organism. …

Modeling Her2 Mutations In Colorectal Cancer Using A Her2 Transgenic Mouse Model And Gastrointestinal Organoids, Elisa Murray

Arts & Sciences Graduate Student Theses and Dissertations

Amplification or mutations in members of the epidermal growth factor receptor family, such as HER2, have been identified in several human diseases. In particular, mutations in the intracellular kinase domain have been identified in breast, colon, and lung cancers. The Cancer Genome Atlas has identified HER2 mutations or gene amplification in seven percent of colon cancer patients. These mutations are well known to promote enhanced cell growth and transformation of colon cancer cell lines. Previous studies have found HER2 mutations to confer anchorage independent growth and activation of downstream signaling pathways such as MAPK. Although HER2 mutations have been extensively …

The Role Of The Circadian Clock Protein Rev-Erba In Neuroinflammation & Synaptic Health, Percy Griffin

Arts & Sciences Graduate Student Theses and Dissertations

Circadian rhythms are cycles of physiological activity that are conserved across all of life’s taxa – ranging from cyanobacteria to humans - due to their importance. They are conserved to allow organisms to maximize their capacity to obtain resources in their environment. In mammals, light and dark input into the retina is the strongest synchronizer of circadian rhythms. On the molecular level, this tightly regulated transcriptional-translational feedback loop is orchestrated by proteins with cyclical expression. The loss of these proteins has functional consequences on human health and diseases.Recently, associations have been made between circadian proteins and a host of pathological …

Mechanisms Of Sting-Associated Vasculopathy And Immunodeficiency, Brock Gordon Bennion

Arts & Sciences Graduate Student Theses and Dissertations

STING N153S in mice and STING N154S in humans cause spontaneous autoimmunity. Specifically, these mutations reduce the numbers of T cells and NK cells, and cause lung disease. However, mice develop perivascular lung inflammation that is distinct from the pulmonary fibrosis observed in human patients. Viral infections are known to exacerbate autoimmunity and foment pulmonary fibrosis. Therefore, we hypothesized that exposure to a virus may influence STING N153S disease in mice. To test this, we infected STING N153S animals with the gammaherpesvirus family member, gHV68, and found that 14 days post infection pulmonary fibrosis was readily observed by histological staining. …

Pathophysiology And Proteogenomics Of Post-Infectious And Post-Hemorrhagic Hydrocephalus In Infants, Albert M. Isaacs

Arts & Sciences Graduate Student Theses and Dissertations

Post-infectious (PIH) and post-hemorrhagic (PHH) hydrocephalus occur as sequalae of neonatal sepsis or intraventricular hemorrhage (IVH) of prematurity, respectively. Together, PIH and PHH represent the most common form of infantile hydrocephalus, the most common indication for neurosurgery in children globally, and the leading cause of neurological morbidity and mortality worldwide. The lack of understanding of the pathophysiology of PIH and PHH, particularly with regards to the host central nervous system response to the antecedent infection and hemorrhage, perturbation of differentiating neural stems in the ventricular (VZ) and subventricular (SVZ) zones, and damage to periventricular white matter (PVWM) tracts carrying sensorimotor …

The Good, The Brown, And The Healthy: Understanding Non-Thermogenic Brown Adipose Function In Obese Mice, Caryn Nicole Carson

Arts & Sciences Graduate Student Theses and Dissertations

Genetic and environmental factors heavily intertwine to affect metabolic homeostasis. To tease out the exact interactions between these two realms of influence, researchers often compare how one or multiple different inbred mouse strains react to various diets. An observation consistently seen across multiple strains on the same diet can reasonably be considered a general dietary effect, whereas an observation seen only in one strain of mice is more likely to result from a genetic cause or gene-by-environment interaction. Similarly to humans, a high fat diet causes many mouse strains to develop obesity and poor metabolic health, with varying degrees of …

Separating Signal From Noise In High-Density Diffuse Optical Tomography, Arefeh Sherafati

Arts & Sciences Graduate Student Theses and Dissertations

High-density diffuse optical tomography (HD-DOT) is a relatively new neuroimaging technique that detects the changes in hemoglobin concentrations following neuronal activity through the measurement of near-infrared light intensities. Thus, it has the potential to be a surrogate for functional MRI (fMRI) as a more naturalistic, portable, and cost-effective neuroimaging system. As in other neuroimaging modalities, head motion is the most common source of noise in HD-DOT data that results in spurious effects in the functional brain images. Unlike other neuroimaging modalities, data quality assessment methods are still underdeveloped for HD-DOT. Therefore, developing robust motion detection and motion removal methods in …

Characterizing The Relationship Between Gut Microbiota Development And Healthy Growth, Hao-Wei Chang

Arts & Sciences Graduate Student Theses and Dissertations

Childhood undernutrition accounts for more than 45% of deaths in children under the age of ve. Children who receive current therapeutic treatment and survive often have long-term complications. These survivors usually exhibit stunted growth, impaired cognitive development and are at risk for immune dysfunction, obesity and associated metabolic abnormalities. Recent studies have revealed a causal relationship between development of the gut microbiota and healthy growth. However, standard therapeutic foods were not designed with a consideration of the developmental biology of the gut microbial community and have limited ef cacy in repairing the perturbed microbiota of undernourished children.We hypothesized that repairing …

The Role Of Escrt-Iii-Like Subunit Ist1 In Membrane Trafficking Pathways, Amy Kate Clippinger

Arts & Sciences Graduate Student Theses and Dissertations

ESCRTs (Endosomal Sorting Complex Required for Transport) are a modular set of proteins with membrane remodeling activities that include the formation and release of intralumenal vesicles (ILVs) to generate multivesicular endosomes. ESCRT-III filaments have an established role in membrane fission for ILV formation and the topologically related processes of viral budding and cytokinesis. Among the 12 ESCRT-III proteins most have established roles in ILV formation, but the cellular roles of IST1 remain elusive. We found that IST1 and another ESCRT-III subunit CHMP1B form filaments that spiral around the outside or cytoplasmic surface of membrane tubules. Consistent with a role in …

Development And Application Of Mass Spectrometry-Based Approaches For Protein Higher Order Structure Analysis And Protein-Protein Interaction Characterization, Mengru Zhang

Arts & Sciences Graduate Student Theses and Dissertations

Proteins, one of the most fundamental biomolecules, adopt unique higher order structures (HOS) to enable diverse biological functions. Deciphering protein HOS is crucial to gain deeper insights of their working mechanisms and to develop biotherapeutics. Mass spectrometry (MS)-based approaches evolved rapidly in the past 30 years and are now playing critical roles in protein HOS characterization. One of those approaches is MS-based footprinting whose principle is to map the solvent accessible surface area (SASA) to deliver structural information. Protein footprinting can be achieved by reversible labeling, e.g., hydrogen-deuterium exchange (HDX), and by irreversible labeling using radical-based reagents or other targeted …

The Role Of Cdx4 During Patterning Of Definitive Hemogenic Mesoderm, John Philip Creamer

Arts & Sciences Graduate Student Theses and Dissertations

The current standard of treatment for a variety of hematopoietic malignancies and genetic disorders is allogenic bone marrow transplantation, where donor hematopoietic stem cells (HSCs) engraft within the host and give rise to all of them hematopoietic lineages necessary for homeostasis. In many cases, finding a compatible human leukocyte antigen (HLA) matching donor is not possible, due to the large amount of genetic variation at those loci, but with the advent of induced pluripotent stem cells (iPSCs), unlimited sources of patient matched cells can be derived. Hematopoietic differentiations of human pluripotent stem cells (hPSCs) have been shown to recapitulate the …

Bumpy Road Ahead: Overcoming Dna Replication Obstacles One Barrier At A Time, Melanie Anne Sparks

Arts & Sciences Graduate Student Theses and Dissertations

DNA replication must occur efficiently and timely every cell cycle to protect the integrity of the genome. Stalled or slowed replication forks lead to replication stress that can cause replication fork collapse, and potentially genome instability. Scattered throughout the genome are tightly bound proteins, such as transcription factors, that are necessary for cell function and survival. These proteins have the potential to impede timely DNA replication. Furthermore, genomic DNA is packaged around histone octamers into structures called nucleosomes that both compact the DNA and provide an additional layer of information and regulation termed epigenetics. Thus, DNA replication is not only …

Chapter 12. Informing Inquiry Into Writing Across The Lifespan From Perspectives On Students With Learning Disabilities Or Autism Spectrum Disorder, Apryl L. Poch, Matthew C. Zajic, Steve Graham

Special Education and Communication Disorders Faculty Publications

The value of writing is not limited to single points of time in our lives but serves many different purposes across the lifespan (Bazerman et al., 2018). For instance, young children begin to experiment with writing as early as two years of age, using it as a vehicle for play, communication, and self-expression (Rowe, 2008). With the advent of school, the purposes for writing expand greatly to include writing to inform, persuade, describe, summarize, learn, and narrate to identify just some of the ways children, adolescents, and young adults learn to write and use writing as part of their education. …

Influence Of Chaperone-Like Activity Of Caseinomacropeptide On The Gelation Behaviour Of Whey Proteins At Ph 6.4 And 7.2, Sophie J. Gaspard, Prateek Sharma, Ciarán Fitzgerald, John T. Tobin, James A. O'Mahony, Alan L. Kelly, Andre Brodkorb

Nutrition, Dietetics, and Food Sciences Faculty Publications

The effect of caseinomacropeptide (CMP) on the heat-induced denaturation and gelation of whey proteins (2.5–10%, w/v) at pH 6.4 and 7.2, at a whey protein:CMP ratio of 1:0.9 (w/w), was investigated using differential scanning calorimetry (DSC), oscillatory rheology (90 °C for 20 min) and confocal microscopy. Greater frequency-dependence in the presence of CMP suggested that the repulsive interactions between CMP and the whey proteins affected the network generated by the non-heated whey protein samples. At pH 6.4 or 7.2, CMP increased the temperature of denaturation of β-lactoglobulin by up to 3 °C and increased the gelation temperature by up to …

A Mega-Analysis Of Personality Prediction: Robustness And Boundary Conditions, Emorie Danielle Beck

Arts & Sciences Graduate Student Theses and Dissertations

Decades of research suggest that personality is an important and robust predictor of life outcomes. However, previous investigations of personality-outcome associations have not adequately accounted for reverse causality and selection bias nor have they examined the boundary conditions of the effects, which has left the robustness conditions of personality-outcome associations unknown. The present study examines the robustness and boundary conditions of personality prediction using 14 personality characteristics to predict 14 health, social, education/work, and societal life outcomes across eight different person- and study-level moderators in 10 longitudinal panel studies in a mega-analytic framework coupled with propensity score matching to control …

Specificity Of Ssb Binding To Its Interacting Proteins And Multiple Allosteric Effects Of Ssb C-Terminal Tail On Assembly And Dna Binding Of E. Coli Recor Proteins, Min Kyung Shinn

Arts & Sciences Graduate Student Theses and Dissertations

The homo-tetrameric E. coli single strand (ss) DNA binding (SSB) protein is an essential component in DNA maintenance for its role in binding and protecting single stranded DNA intermediates via its N-terminal DNA binding domain (DBD). SSB also acts as a hub to recruit at least 17 SSB interacting proteins (SIPs) involved in DNA replication, recombination, and repair via its 9 amino acid C-terminal acidic tip region. A 56 amino acid intrinsically disordered linker connects the DBD and the acidic tip and plays a role in cooperative binding to ssDNA. Using isothermal titration calorimetry, I determined that the SSB-Ct peptides …

Wavelet Coherence Analysis With An Application Of Brain Images, Yiqian Fang

Arts & Sciences Graduate Student Theses and Dissertations

Wavelet analysis has become an emerging method in a wide range of applications with non-stationary data. In this work, we apply wavelets to tackle the problem of estimating dynamic association in a collection of multivariate non-stationary time series. Coherence is a common metric for linear dependence across signals. However, it assumes static dependence and does not sufficiently model many biological processes with time-evolving dependence structures. We explore continuous wavelet analysis for modeling and estimating such dynamic dependence under the replicated multivariate time series settings. Wavelet transformation provides a decomposition of signals that localizes in both time and frequency domains, hence …

Sustainable Diets For Planetary Health: A Study Of Indigenous Based Agri-Food Systems In A Community Of The Central Highlands Of Ecuador, Carlos Andres Gallegos-Riofrio

Arts & Sciences Graduate Student Theses and Dissertations

In order to explore the psychosocial and agroecological dimensions of sustainable diets and their roles in the rural Andean community of Caliata in the Ecuadorian highlands, I conducted a community-centered participatory mixed-methods study. Thirty-nine focus groups and ten key informant interviews were conducted, recorded, translated, transcribed, and analyzed using three-stage coding. The information was triangulated using participant observation, local records, and descriptive statistics from a survey of 57 female household heads, which included a modified 48-hour dietary recall module. Rural appraisal research assessed agroecological dimensions. Ten purposively selected sites were studied alongside local informants in order to obtain diversity indexes …

Production Of Medical Radioisotopes Using Titanium Accelerator Targets, Christopher Shaun Loveless

Arts & Sciences Graduate Student Theses and Dissertations

Theranostic radiopharmaceuticals enable diagnostic imaging and radionuclide therapy in patients using a single molecular agent labeled with a diagnostic-therapeutic pair (e.g., 68Ga/177Lu) or a theranostic radionuclide (e.g., 131I). This theranostic approach can help inform patient-specific treatment plans and improve clinical outcomes. Radionuclide pairs used in theranostic agents fall into two categories: pseudo matched-pairs (e.g., 68Ga/177Lu) and matched-pairs (e.g., 124I/131I). Pseudo matched-pair radionuclides have similar chemistries and pharmacokinetics when bound to the same bioconjugate molecule. In contrast, identical chemistries and pharmacokinetics can be obtained by using the matched-pair radionuclides.The isotopes of Sc include two diagnostic radioisotopes, 43Sc & 44Sc, and one …

Peer-Led Team Learning In Calculus-Based Introductory Physics: Implementation And Evaluation, Siera Maia Stoen

Arts & Sciences Graduate Student Theses and Dissertations

Robust evidence shows that Peer-led Team Learning (PLTL) improves the academic success of college students in introductory Science, Technology, Engineering, and Mathematics (STEM) courses. However, further research is needed to gain a fuller understanding of the benefits of PLTL and the aim of this dissertation is to explore two key and understudied questions surrounding the effects of PLTL. First, does deviating from the optimal implementation of PLTL change its effectiveness? Second, what specific outcomes, in addition to academic success (e.g., exam scores), does PLTL improve? This dissertation will provide a fuller picture of the impact of PLTL by examining its …

Safekeeping: Slavery, Capitalism, And The Carceral State In Washington, D.C., 1830-1863, Brandon Wilson

Arts & Sciences Graduate Student Theses and Dissertations

By the 1830s, incarceration emerged as a two-pronged solution for racial control and economic expansion. Local and federal government built jails around the District of Columbia to detain "rowdy negro boys," men, and women, as a means to stymie their rapid movement and fuel a burgeoning domestic slave trade. People were jailed, fined, and often sold to the Deep South, providing a wellspring of capital for enslavers, justified through the lens of criminality. For the crime of petty theft, missing free papers, or in at least one case "using foul language," black people of the Washington region could find themselves …