Digital Commons Network^™

Role Of The Exopolysaccharide Alginate In Adherence To And Inflammation Of Pulmonary Epithelial Cells, Brian E. Crossley

Theses and Dissertations

Pseudomonas aeruginosa (PA) infections in Cystic Fibrosis (CF) patients are not easily cleared due to the conversion from a nonmucoid to a mucoid phenotype. Alginate is an acetylated exopolysaccharide produced by mucoid PA that is responsible for increased resistance to antibiotics, host phagocytic killing, and propagating biofilm formation. Understanding the interaction between PA and host cells is critical to understanding chronic infection and inflammation in CF. In order to investigate this, we used A549 pulmonary epithelial cells and murine alveolar macrophages (MH-S) to examine host response to nonmucoid versus mucoid PA infection. Adhesion assays in A549 pulmonary epithelial cells revealed …

Identifying Parameters For Robust Network Growth Using Attachment Kernels: A Case Study On Directed And Undirected Networks, Ahmed F. Abdelzaher

Theses and Dissertations

Network growing mechanisms are used to construct random networks that have structural behaviors similar to existing networks such as genetic networks, in efforts of understanding the evolution of complex topologies. Popular mechanisms, such as preferential attachment, are capable of preserving network features such as the degree distribution. However, little is known about such randomly grown structures regarding robustness to disturbances (e.g., edge deletions). Moreover, preferential attachment does not target optimizing the network's functionality, such as information flow. Here, we consider a network to be optimal if it's natural functionality is relatively high in addition to possessing some degree of robustness …

Finding The Cutpoint Of A Continuous Covariate In A Parametric Survival Analysis Model, Kabita Joshi

Theses and Dissertations

In many clinical studies, continuous variables such as age, blood pressure and cholesterol are measured and analyzed. Often clinicians prefer to categorize these continuous variables into different groups, such as low and high risk groups. The goal of this work is to find the cutpoint of a continuous variable where the transition occurs from low to high risk group. Different methods have been published in literature to find such a cutpoint. We extended the methods of Contal and O’Quigley (1999) which was based on the log-rank test and the methods of Klein and Wu (2004) which was based on the …

Evaluating And Improving The Efficiency Of Software And Algorithms For Sequence Data Analysis, Hugh L. Eaves

Theses and Dissertations

With the ever-growing size of sequence data sets, data processing and analysis are an increasingly large portion of the time and money spent on nucleic acid sequencing projects. Correspondingly, the performance of the software and algorithms used to perform that analysis has a direct effect on the time and expense involved. Although the analytical methods are widely varied, certain types of software and algorithms are applicable to a number of areas. Targeting improvements to these common elements has the potential for wide reaching rewards. This dissertation research consisted of several projects to characterize and improve upon the efficiency of several …

An Examination Of The Technical And Relational Hypotheses Of Motivational Interviewing In A Sample Of African American Adolescent Girls Seeking Obesity Treatment, Rachel L. Boutte

Theses and Dissertations

Adolescent obesity has increased exponentially over the past three decades in the United States. In response, behavioral interventions have been developed and implemented to address this epidemic; however, treatment adherence is often suboptimal. Motivational interviewing (MI) is a directive, person centered approach to reducing patient ambivalence about change, which has been shown to increase engagement in obesity interventions. The current study investigated the underlying process of MI by exploring two different, but related pathways that explain how change happens (e.g., the technical and relational hypotheses) in the context of a multidisciplinary obesity intervention with African American adolescent girls (N …

The Development Of Bicyclic Peptide Library Scaffolds And The Discovery Of Biostable Ligands Using Mrna Display, David E. Hacker

Theses and Dissertations

Peptides are a promising class of therapeutic candidates due to their high specificity and affinity for cellular protein targets. However, peptides are susceptible to protease degradation and are typically not cell-permeable. In efforts to design more effective peptide drug discovery systems, investigators have discovered that incorporation of non-canonical amino acids (ncAAs) and macrocyclization overcome these limitations, making peptides more drug-like.

In this work, we exploit the promiscuity of wild-type aminoacyl-tRNA synthetases (aaRSs) to ‘mischarge’ ncAAs onto tRNA and ribosomally incorporate them into peptides using a cell-free translation system. We have demonstrated the ability to incorporate five ncAAs into a single …

Crystallographic Study Of Mutant Influenza Matrix (M1) Protein And Affinity Study Of Small Molecule Inhibitors Toward M1 And Growth Factors, Bashayer Althufairi

Theses and Dissertations

Influenza A virus (IAV) is a seasonal infectious agent that could cause a major worldwide catastrophe. Due to its genetic properties, IAV generates new viral particles that resist the body’s immune defense and antiviral drug therapy. This occurs when a host cell has been co-infected by different IAV strains leading to the generation of hybrid viruses. This process is called reassortment. The majority of these new IAVs contain genetically altered hemagglutinin (HA) and neuraminidase (NA). Unfortunately, all current IAV drug therapies target the highly mutated proteins, HA and NA, which is not very useful. Influenza matrix protein 1 (M1) is …

Magic At The Crossroads: The Rise Of The Video Essay, Morganne Tinsley August

Theses and Dissertations

This thesis examines the birth, rise in popularity, and evolution of the video essay, a subgenre of the essay found recently in online literary journals. Chapter one provides a brief history of the alphabetic essay as it expands to include photo essays, audio essays, and essay-films. The second chapter outlines the history of the online literary journal and John Bresland’s role in the introduction of the video essay as it appears in online journals. Chapter three contains an examination of the way image, text, and sound function in video essays and the tools and strategies essayists are using to create …

Modeling Spatially Varying Effects Of Chemical Mixtures, Jenna Czarnota

Theses and Dissertations

Cancer incidence is associated with exposures to multiple environmental chemicals, and geographic variation in cancer rates suggests the importance of accommodating spatially varying effects in the analysis of environmental chemical mixtures and disease risk. Traditional regression methods are challenged by the complex correlation patterns inherent among co-occurring chemicals, and the applicability of geographically weighted regression models is limited in the setting of environmental chemical risk analysis. In comparison to traditional methods, weighted quantile sum (WQS) regression performs well in the identification of important environmental exposures, but is limited by the assumption that effects are fixed over space. We present an …

Obesity And Asthma: Adiponectin Receptor 1 (Adipo R1) And Adiponectin Receptor 2 (Adipo R2) Are Expressed By Normal Human Bronchial Epithelial (Nhbe) Cells At Air-Liquid Interface (Ali) And Expression Changes With Il-13 Stimulation, Jennifer L. Bradley

Theses and Dissertations

Obesity is recognized as an important risk factor for the development of many chronic diseases such as hypertension, Type 2 diabetes mellitus (T2DM) cardiovascular disease, cancer, renal disease, neurologic dysfunction, metabolic syndrome and asthma (3, 4). Circulating serum adiponectin levels in obese asthmatics have been reported to be low. Therefore, we aimed to investigate the role of adiponectin in a mucus hypersecretion model and hypothesized that adiponectin would decrease IL-13 induced MUC5AC expression from differentiated NHBE cells and that increasing concentrations of IL-13 would cause a decrease in Adipo R1 and Adipo R2 expression. MUC5AC expression with exposure to adiponectin …

In Pursuit Of Women Scientists: Using Science Plays To Promote Women Entering Stem Disciplines, Danielle Hartman

Theses and Dissertations

Higher education currently seeks to increase female enrollment in STEM. Women face many challenges attempting to breach this male dominated arena with misconceptions, gender stereotypes, and few female role models. With the recent trend in higher education to encourage more women to enter the STEM disciplines and K-12 schools cutting funding for arts programs, theatre may be losing its value in the education system. The value of interdisciplinary studies is beginning to be forgotten during the grade school years as school boards battle budget cuts, but we can remind society of it through science plays. Theatre artists use other disciplines …

A Study Of The Action Of Risperidone At 5-Ht2a Receptors, Supriya A. Gaitonde

Theses and Dissertations

Risperidone is an ‘atypical’ antipsychotic and is approved by the USFDA mainly for the treatment of schizophrenia and symptoms of bipolar disorder. Risperidone (an SDA or serotonin-dopamine antagonist) has ~20-fold higher affinity at 5-HT_2A receptors over dopamine D₂ receptors, which makes it more efficacious against the negative symptoms of schizophrenia and less liable to causing extrapyramidal side effects than ‘typical’ antipsychotics.

The major goal of the current investigation was to study the structure of risperidone and to identify the minimum structural features required for 5-HT_2A receptor affinity that retain antagonist action. The structure of risperidone was systematically …

Emergent Interactions Influence Functional Traits And Success Of Dune Building Ecosystem Engineers, Joseph K. Brown

Theses and Dissertations

Stability of coastal systems are threatened by oceanic and atmospheric drivers of climate change. Sea-level rise compounded with increased frequency and intensity of storms emphasizes need for protection of inner island systems by dune formations. Dune building processes are affected by interactions between growth of ecosystem engineering dune grasses and environmental factors associated with disturbance such as sand burial and salt spray. Climate change may also cause latitudinal expansion of some species, resulting in emergence of competitive interactions that were previously absent. Topographic structure of coastlines, traditionally influenced by sand burial, could change as a result of competition emergence. My …

The Effect Of Pre-Deployment Physiology As A Predictor Of Post-Traumatic Stress Disorder Among A Sample Of United States Army National Guard And Reserve Soldiers, David J. Rothman

Theses and Dissertations

Potential risk factors for development of Post-Traumatic Stress Disorder (PTSD) are still unclear. One potential risk factor for the development of PTSD is an individual’s cardiovascular reactivity and recovery in response to stressor tasks. The current study was conducted with 763 Army National Guard and Army Reserve soldiers. Participants completed a stressful induction along with self-report measures prior to deployment. Post-deployment, self-report measures were completed to assess PTSD symptomatology and experiences related to deployment and combat. Multiple regression was used to determine the ability of blood pressure response to stress to predict PTSD symptoms immediately and one-year after return from …

Filter Performance Under Simulated Real-World Conditions, Qiang Wang

Theses and Dissertations

Evaluating the performance of filter media for filtration applications is essential to assure design engineers and users that filter device will deliver promised performance for specific applications under the environmental stress. The study of particle loading characteristics of filter media in the laboratory setting is typically performed under the steady flow conditions, i.e., at the constant particle concentration and flow rate. In reality, filtration products are operated under the situations that the flow rate and mass concentration of particles are varied in time. The success of translating the laboratory data to estimate the performance of filter media in the fields …

Independent Origination Of Floral Zygomorphy, A Predicted Adaptive Response To Pollinators: Developmental And Genetic Mechanisms, Ghadeer Bukhari, Wenheng Zhang

Theses and Dissertations

Observations of floral development indicate that floral organ initiation in pentapetalous flowers more commonly results in a medially positioned abaxial petal (MAB) than in a medially positioned adaxial petal (MAD), where the medial plane is defined by the stem and the bract during early floral development. It was proposed that the dominant MAB petal initiation might impose a developmental constraint that leads to the evolution of limited patterns of floral zygomorphy in Asteridae, a family in which the floral zygomorphy develops along the medial plane and results in a central ventral (CV) petal in mature flowers. Here, I investigate whether …

A Study Of The Effect Of Harvesting On A Discrete System With Two Competing Species, Rebecca G. Clark

Theses and Dissertations

This is a study of the effect of harvesting on a system with two competing species. The system is a Ricker-type model that extends the work done by Luis, Elaydi, and Oliveira to include the effect of harvesting on the system. We look at the uniform bound of the system as well as the isoclines and perform a stability analysis of the equilibrium points. We also look at the effects of harvesting on the stability of the system by looking at the bifurcation of the system with respect to harvesting.

N-Methyl 4-Methyl Amphetamine N-Alkyl Chain Extension Differentially Affects Ion Flux At The Human Dopamine And Norepinephrine Transporters, Alan C. Harris Jr.

Theses and Dissertations

Amphetamine (AMPH) and its derivatives embody a remarkable breadth of pharmacology. These molecules exert their effects, both therapeutic and pathological, at the human monoamine transporters, which tune synaptic dynamics by evacuating monoamine neuromodulators from the synapse subsequent to neuronal impulses. These transporters are electrogenic, and the transporter-mediated current can be correlated to a surrogate measure of the change in membrane voltage: Ca⁺⁺ currents from co-transfected L-type Ca⁺⁺ channels. The present work makes use of this assay, with which it is possible to derive pharmacodynamic metrics from both substrates and inhibitors. This work presents data on a heretofore-unstudied class …

Pharmacological Implications Of Adenosine 2a Receptor- Dopamine Type 2 Receptor Heteromerization, Candice N. Hatcher-Solis

Theses and Dissertations

G protein-coupled receptors (GPCRs) are heptahelical, transmembrane proteins that mediate a plethora of physiological functions by binding ligands and releasing G proteins that interact with downstream effectors. GPCRs signal as monomers, complexes of the same receptor subtype (homomers), or complexes of different receptor subtypes (heteromers). Recently, heteromeric GPCR complexes have become attractive targets for drug development since they exhibit distinct signaling and cell-specific localization from their homomeric counterparts. Yet, the effect of heteromerization on the pharmacology of many GPCR homomers remains unknown. Therefore, we have undertaken the task to examine the effect of heteromerization on G_s signaling through the …

In-House Fabrication Of Multi-Sized Polystyrene Microcarriers For Neural Stem Cell Expansion, Jessica Forrester

Theses and Dissertations

The clinical demand for neural stem cells drives the need for a reproducible method used to generate a large quantity of well-characterized cells to support regenerative therapies. Microcarriers are currently being used as a scaffold for stem cell culture to aid in this expansion process because they provide a larger surface area while also requiring fewer cell passages compared to monolayer culture. The main objective of this project was to investigate how human neural stem cell attachment, proliferation, and multipotency would respond to three-dimensional (3D) culture using peptide-coated microcarriers of varying diameters. In this study, multi-sized polystyrene microcarriers were fabricated …

Fabricating Superhydrophobic And Superoleophobic Surfaces With Multiscale Roughness Using Airbrush And Electrospray, Karam N. Almilaji

Theses and Dissertations

Examples of superhydrophobic surfaces found in nature such as self-cleaning property of lotus leaf and walking on water ability of water strider have led to an extensive investigation in this area over the past few decades. When a water droplet rests on a textured surface, it may either form a liquid-solid-vapor composite interface by which the liquid droplet partially sits on air pockets or it may wet the surface in which the water replaces the trapped air depending on the surface roughness and the surface chemistry. Super water repellent surfaces have numerous applications in our daily life such as drag …

Response Of Soil Microbial Communities To Saltwater Intrusion In Tidal Freshwater Wetlands, Chansotheary Dang

Theses and Dissertations

Saltwater intrusion due to global change is expected to have a detrimental effect on the biogeochemistry of tidal freshwater wetlands. Of particular concern is that fact that salinization can alter the role of these ecosystems in the global carbon cycling by causing shifts in microbial metabolism that alter greenhouse gas emissions and increase carbon mineralization rates. However, our understanding of how wetland microbial community dynamics will respond to saltwater intrusion is limited. To address this knowledge gap and increase our understanding of how microbial communities in tidal freshwater wetlands change over time (1, 3, 12, and 49 weeks) under elevated …

Gender Nonconforming, Transgender, And Transsexual Patient Navigation Of The American Health Care System: Locating A Primary Care Provider, Justin M. Vinneau

Theses and Dissertations

This study explores the experiences of gender nonconforming (GNC), transgender, and transsexual (trans) people in the search for a primary care provider in the United States. The current body of literature on transgender health often discusses HIV rates, substance use, mental health/suicide, and few studies have studies primary care seeking behaviors; this study seeks to provide new insight into the primary care (pcp) seeking behaviors of GNC and trans people. The primary theoretical perspectives utilized in this study were West and Zimmerman’s (1987) “Doing Gender” and the Health Beliefs Mode (Ayers et al., 2007; Connor and Norman, 2005; Green and …

Predictors Of Caffeine-Related Withdrawal Symptoms In College Freshmen, David J. Pomm

Theses and Dissertations

While caffeine withdrawal has been well-characterized, research on caffeine intake and factors associated with withdrawal has been limited. The present study examined prevalence rates of caffeine use and identified psychosocial factors associated with having caffeine withdrawal headaches (CWH). Participants were N = 1,989 college freshmen who participated in the 2011 Spit for Science project. Caffeine use was reported by 80% of the sample. Females were more likely than males to consume caffeine, and soda was the primary source of caffeine for both genders. As hypothesized, daily caffeine users were more likely to report CWH than non-daily users. When multivariable analyses …

Continuous Stationary Phase Gradients For Planar And Column Chromatography, Veeren Dewoolkar

Theses and Dissertations

Surfaces that exhibit a gradual change in their chemical and/or physical properties are termed as surface gradients. Based on the changes in properties they are classified either as physical or chemical gradients. Chemical gradients show variations in properties like polarity, charge, functionality concentration and have found potential applications in fields of biology, physics, biosensing, catalysis and separation science. In this dissertation, surface gradients have been prepared using controlled rate infusion (CRI).

CRI is a simple method in which a surface gradient is formed by carrying out the infusion of organoalkoxysilane in a time-dependent fashion using a set infusion rate. Depending …

Evaluation Of Redox Potential As A Novel Biomarker Of Oxidative Stress, Inflammatory Response, And Shock Using Nanoporous Gold Electrodes, Matthew C. Ellenberg

Theses and Dissertations

EVALUATION OF REDOX POTENTIAL AS A NOVEL BIOMARKER OF OXIDATIVE STRESS, INFLAMMATORY RESPONSE, AND SHOCK USING NANOPOROUS GOLD ELECTRODES

Background: Redox potential is a chemical species’ affinity for electrons. Increased oxidant concentration is associated with disease1,2, yet there is not a way to measure systemic redox status.3 Redox potentiometry uses metal electrodes that do not work in blood because protein molecules adhere on the metal surface, blocking electron exchange.

Methods: Nanoporous gold electrodes have large surface areas that allowed electron exchange to continue in blood.4 Redox potential was measured in blood with ascorbic acid, in cardiac bypass patients and pigs …

From Seed To Sky: Impacts Of Explosive Compounds On Vegetation Across Spatial And Developmental Scales, Stephen M. Via

Theses and Dissertations

Explosive compounds are broadly distributed across the globe as a result of nearly two centuries of munitions use in warfare and military activities. Two explosive compounds have seen disproportionate use; RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine) and TNT (2-methyl- 1,3,5-trinitrobenzene), being the most commonly found explosives in the environment. The effects of explosives on biota have been studied in great detail; however, there is a general lack of understanding with regard to broader ecological impacts of these contaminants. My dissertation objective was to follow the impacts of explosive compounds on vegetation across scales. Impacts on vegetation at the species scale alter community composition via …

The Molecular And Mechanical Mechanisms Of The Age-Associated Increase In The Severity Of Experimental Ventilator Induced Lung Injury, Joseph Ames Herbert

Theses and Dissertations

Abstract

Background

The majority of patients requiring mechanical ventilation are over the age of 65 and advanced age is known to increase the severity of ventilator-induced lung injury (VILI) and mortality. However, the mechanisms which predispose aging ventilator patients to increased mortality rates are not fully understood.

Pulmonary edema is a hallmark of VILI and the severity of edema increases with age. Ventilation with conservative fluid management decreases mortality rates in acute respiratory distress (ARDS) patients, but has not been investigated in VILI. We hypothesized that age-associated increases in pulmonary edema promote age-related increases in ventilator-associated mortality. Endoplasmic reticulum (ER) …

Host Densities And Parasitism Rates In A Forest Defoliator Across A Rural-Urban Landscape, Abigail J. Nelson

Theses and Dissertations

Fall cankerworm (FCW) outbreaks have recently increased in frequency and intensity in the mid-Atlantic region of the United States, especially around cities of Charlotte, NC and Richmond, VA. This study evaluated the effects of two landscape features associated with urbanization, impervious surface and forest cover, on population patterns of FCW and its parasitoids across eastern Virginia. Forest cover was positively related to parasitism rates while impervious surface was positively related to FCW abundance, suggesting that FCW outbreaks may be amplified in urban areas. FCW abundance declined over the two-year period of this study, but parasitism rate increased at most sites. …

One Of Us, Farrah T. Al Sulaiman

Theses and Dissertations

With this thesis, I reflect on my identity as a Saudi American. I look at how nonverbal communication through gesture and artifact presents the potential for both communication breakdowns, as well as shared understanding. From the lens of Saudi culture, I consider how gender relations and intra-national tribal factions play a role in the division of society, which my work seeks to overcome, at both the national and global levels. My exhibit, One of Us, interrogates one of the most controversial gestures in contemporary society: veiling. As I discuss the notion of camouflage, I review the types of veils available …