Digital Commons Network^™

Gene By Environment Interaction On Weight-Related Outcomes Over Time In Underserved African-American Adults, Tyler Coe Mcdaniel

Theses and Dissertations

Obesity research in the area of prevention has become a national priority given the increasingly high prevalence rate of this condition among US adults, and subsequent health risks that are associated. The etiology of obesity is complex, so a more comprehensive understanding of the interaction between genetic predisposition and the social environment in regards to obesity in adults would advance our knowledge for future public health and prevention efforts. This study’s aim was to assess the impact of a gene by neighborhood social environment interactions on weight-related (i.e., waist circumference) and stress-related (i.e. cortisol) outcomes in underserved African-American adults. A …

Life Satisfaction In Adolescents With High-Functioning Autism Spectrum Disorder, Kathleen Blackburn Franke

Theses and Dissertations

The present study was informed by the Emerging Disability Paradigm, which emphasizes the importance of research regarding positive experiences, personality, and social relationships for individuals with disabilities (Schalock, 2004). The purpose of this study was to provide preliminary evidence regarding the reliability and validity of measures of self-reported psychosocial assets and life satisfaction (LS) for adolescents with high-functioning autism spectrum disorder (HFA). Additional purposes included identifying the overall levels of general and domain-specific LS within adolescents with HFA, comparing these levels to those of a sample of typically developing adolescents, and describing the relation between psychosocial assets and LS for …

Family Oriented Values, Emerging Adulthood, And Tobacco Use Among Hispanic Emerging Adults, Melek Yildiz Spinel

Theses and Dissertations

Theory and research on emerging adulthood (ages 18 to 25) have increased in the past two decades. However, few studies have assessed how different cultural values and experiences influence the experiences of ethnic minority emerging adults. The first objective of the current study was to expand the field of emerging adulthood research by exploring how familism, the belief that family is central to a person’s life, related to their experience of emerging adulthood. Specifically, the study assessed how familism related to Arnett’s proposed experiences of emerging adulthood (identity exploration, self focused, other-focused, feeling in between, the age of instability/negativity, and …

Advanced Clearing Methods And Imaging Techniques For Optimized Three- Dimensional Reconstruction Of Dense Tissues, Caleb A. Padgett

Theses and Dissertations

Advances in tissue clearing have allowed biological and biomedical researchers to image entire segments of tissue and generate three-dimensional reconstructions, allowing for a better understanding of the structural and morphological characteristics of large tissues. This study compared three commonly utilized clearing methods and analyzed their effectiveness in increasing imaging depth for three-dimensional reconstruction of large tissue segments. Mouse heart, mouse brain, mouse colon, and embryonic chick tissues were cut into thick sections, cleared and immunolabeled with an antibody specific to each tissue type, and imaged using a confocal microscope. The results of this study concluded that most tissues cleared by …

Semiparametric Statistical Estimation And Inference With Latent Information, Qianqian Wang

Theses and Dissertations

In Chapter 1, we predicted disease risk by transformation models in the presence of missing subgroup identifiers. When a discrete covariate defining subgroup membership is missing for some of the subjects in a study, the distribution of the outcome follows a mixture distribution of the subgroup-specific distributions. Taking into account the uncertain distribution of the group membership and the covariates, we model the relation between the disease onset time and the covariates through transformation models in each sub-population, and develop a nonparametric maximum likelihood based estimation implemented through EM algorithm along with its inference procedure. We further propose methods to …

Construction Of Supramolecular And Coordination Compounds From Pyridyl Bis-Urea Macrocycles, Bozumeh Som

Theses and Dissertations

The self-assembly of macrocyclic molecules in solution and in the solid state modulates and in many cases enhances their properties for applications in sensing, catalysis and optoelectronics. The self-assembled structures are typically organized by non-covalent interactions such as hydrogen bonding, π-π stacking and dipole-dipole interactions. Our group has focused on the design and synthesis of bis-urea macrocycles that can self-assemble into solid cylinders or tubular structures affording crystalline materials. These macrocycles consist of two urea groups and two rigid C-shaped spacers. Easy functionalization of this system enables access to bis-urea macrocycle structures that could serve as molecular reactors, coordinating ligands …

Reevaluating The Parenting Wellbeing Gap: Evidence From The Wellbeing Module Of The American Time Use Survey, Daniela Veronica Negraia

Theses and Dissertations

Both scholars and the public have been intrigued by the question of whether parents experience higher levels of emotional wellbeing than adults who are not raising children. Yet despite decades of research on the topic, the answer to this question remains unclear. Using a novel source of nationally representative data, the Wellbeing Module of the American Time Use Survey (2010, 2012, 2013), this dissertation aims to unpack and extend prior understanding of the parenting wellbeing gap by pursing two studies. The first investigates whether parenthood may have both positive and negative links to adults’ emotional wellbeing; whether the gap varies …

Phenotypic Response Of Marine Cryptophytes To Varying Spectral Irradiance, Kristin M. Heidenreich

Theses and Dissertations

Cryptophytes are eukaryotic algae found in a variety of aquatic ecosystems, that vary in the color of light available for photosynthesis. This algal division displays a diversity in necessary photosynthetic pigments, possessing either phycoerythrin (Cr-PE; “pink”) phycocyanin (Cr-PC; “green”). According to the theory of complementary chromatic adaptation, this diversity should help maximize absorption of light within natural environments. The objective of this study was to determine if pigmentation related to growth performance in environments of differing spectral irradiance. Eight species of marine cryptophytes (5 Cr-PE and 3 Cr-PC species) were grown under four different spectral light environments. Growth rates, cellular …

Epistemological Issues In Quality Of Life Measurement And Their Implications, Laura M. Cupples

Theses and Dissertations

This project explores the epistemology of quality of life measurement. Quality of life measures face a dual epistemic burden both to serve as data for the evidence-based medicine movement and to give patients a greater voice (McClimans 2017). Much time, effort, and money has been invested in these measures over the last 50 years, and yet their theoretical foundations remain weak. It is not clear whether these instruments succeed in measuring what they purport to measure, or what precisely is meant by “quality of life” (Hunt 1997). The epistemic challenges faced in quality of life measurement are not wholly unique. …

Influence Of Energy Availability On The Carbon Isotopes Of Methane And Biomarkers During Hydrogenotrophic Methanogenesis, Tran Nguyen

Theses and Dissertations

Signatures of organic molecules in the environment are widely used to identify microbial metabolic processes and to track the cycling of carbon. The lipid biomarkers of methane cycling archaea are of particular interest as they are unique, preserved over geologic time scales, and reflect processes that impact an important greenhouse gas. Their isotopic compositions have been used to distinguish regions where archaea produce and anaerobically consume CH4. Previous work has demonstrated that energy availability impacts the stable carbon isotopes of CH4 during microbial synthesis from H2 and CO2. Here, we investigated whether this relationship could be extended to lipids and …

The Effects Of An Integrative Universally Designed Motor Skill Intervention Across General, Inclusion, And Self-Contained Early Childhood Center Classrooms, Sally A. Taunton

Theses and Dissertations

This dissertation consists of two studies that examine the effects of a school-based universally designed integrative intervention on the gross motor, fine motor, and health-related fitness skills of preschool and kindergarten with and without disabilities. Both studies focused on the effects of a school-based universally designed integrative intervention across general, inclusion and self-contained early childhood classroom settings. Study 1 examined the effects of the universally designed integrative intervention in general and inclusion classrooms in children without disabilities, and children with mild to moderate disabilities. Study 2 examined the effects of the universally designed integrative intervention in self-contained classrooms for children …

Ecology And Virulence Capabilities Of Vibrios Isolated From The Pristine North Inlet Estuary, Savannah Leigh Klein

Theses and Dissertations

Vibrio bacteria are Gram negative, motile organisms that occur naturally in most coastal and estuarine ecosystems. Some vibrios are important human pathogens, including Vibrio parahaemolyticus and Vibrio vulnificus. The CDC estimates that vibrios cause 80,000 cases of disease each year in the United States alone. Most cases are caused by V. parahaemolyticus, which infects humans after the consumption of contaminated raw or undercooked seafood, primarily oysters. V. parahaemolyticus causes mild gastroenteritis that is self-limiting unless the patient is immunocompromised. V. vulnificus has a much lower incidence of disease (100 cases in the USA yr-1); however, this organism causes much more …

Constructing Scientific Knowledge: The Understanding Of The Slow Virus, 1898-1976, Burke Hood Dial

Theses and Dissertations

Scrapie is the ovine form of the transmissible spongiform encephalopathies. The understanding of scrapie as a slow viral disease was developed through an international scientific dialogue during the first half of the twentieth century. British investigators used epidemiological and experimental observations to define its very long incubation period before the appearance of symptoms. This enabled French researchers to prove scrapie could be transmitted from sick to healthy animals and allowed them to define the etiological agent as an ultramicroscopic, filterable virus. Following this, an Icelandic scientist, Björn Sigurdsson, investigated two other ovine diseases characterized by unusually long periods between contracting …

Association Between Mechanics And Biology In Vascular Graft Remodeling, David Andrew Prim

Theses and Dissertations

Coronary artery bypass grafting (CABG) restores myocardial perfusion in patients with severe coronary artery disease by utilizing autografts – usually at least one of the internal thoracic artery (ITA), radial artery (RA), and great saphenous vein (GSV) – to bypass stenosed regions of coronary arteries. While decades of research and clinical improvements have made CABG an indispensable procedure, tens of thousands of grafts fail each year, which is due, at least in part, to an inability of the source vessels to adapt to the altered stimuli of the coronary circulation. In this dissertation, we first quantify and compare the mechanical …

Complete Measurement System For Measuring High Voltage And Electrical Field Using Slab-Coupled Optical Fiber Sensors, Nikola Stan

Theses and Dissertations

A slab-coupled optical fiber sensor (SCOS) falls into a narrow class of all-dielectric optical fiber electric field sensors, which makes it a perfect candidate for measurements of high electric fields in environments where presence of conductors is highly perturbing to the system under test. Its nonlinear response to high fields requires a new nonlinear calibration technique. A nonlinear calibration method is explained and demonstrated to successfully measure high electric fields, as well as high voltages with dynamic range up to 50 dB. Furthermore, a SCOS can be fitted into narrow spaces and make highly localized measurements due to its small …

Role Of Sphingosine-1-Phosphate Receptors In Cytokine And Chemokine Production By Glia, Jean Moon

Theses and Dissertations

About 1 in 10 newly diagnosed HIV cases in the United States are attributed to injection drug abuse. Opiate abuse exacerbates HIV disease progression in the central nervous system by disrupting glial function and significantly augmenting glial-derived pro-inflammatory mediators. Astroglia and microglia exposed to viral proteins, such as transactivator of transcription (Tat), become activated leading to release of a large number of cytokines and chemokines and a positive loop of neuro-inflammation. Despite effective antiretroviral therapy, persistent inflammation and immune activation affect HIV-infected individuals. A potential alternative target is sphingosine 1-phosphate receptor 1 (S1PR1) which is known to play a role …

Activation Of Trpv1 By Capsaicin Regulates Enac, Alexander Saffran

Theses and Dissertations

ENaC is a constitutively open heterotrimeric channel which regulates Na⁺ transport in tight epithelia of the kidney, lungs, colon and anterior tongue containing fungiform taste buds. The amiloride-sensitive ENaC is comprised of aβg subunits. Humans express an additional subunit, the d subunit. Therefore, humans contain both aβg-ENaC and dβg-ENaC functional channels. Relative to aβg-ENaC, the dβg-ENaC is 10-fold less sensitive to amiloride. In the mammalian anterior tongue, ENaC is expressed in fungiform salt sensing taste receptor cells and is the Na⁺-specific salt taste receptor. In mammals, salt elicits an inverted U shaped behavioral response. Lower concentrations of …

Improving The Conservation Of A Cryptic Endangered Freshwater Mussel (Parvaspina Collina) Through The Use Of Environmental Dna And Species Distribution Modeling, Bonnie A. Roderique

Theses and Dissertations

Conservation efforts that involve habitat protection, population augmentation, and species reintroductions require knowledge of the habitat requirements, distribution, and abundance of a species—information that can be challenging to acquire, especially for rare organisms with patchy distributions. In this thesis, I develop a protocol for the use of environmental DNA (eDNA) and create a Species Distribution Model for the endangered James spinymussel, Parvaspina collina (Unionidae). The results of this work show that eDNA is a robust tool for identifying species presence but not for estimating the relative abundance of populations. This study found that P. collina’s distribution is influenced by abiotic …

Motion-Induced Artifact Mitigation And Image Enhancement Strategies For Four-Dimensional Fan-Beam And Cone-Beam Computed Tomography, Matthew J. Riblett

Theses and Dissertations

Four dimensional imaging has become part of the standard of care for diagnosing and treating non-small cell lung cancer. In radiotherapy applications 4D fan-beam computed tomography (4D-CT) and 4D cone-beam computed tomography (4D-CBCT) are two advanced imaging modalities that afford clinical practitioners knowledge of the underlying kinematics and structural dynamics of diseased tissues and provide insight into the effects of regular organ motion and the nature of tissue deformation over time. While these imaging techniques can facilitate the use of more targeted radiotherapies, issues surrounding image quality and accuracy currently limit the utility of these images clinically.

The purpose of …

Identification Of Taxonomic And Functional Ichthyofaunal Zones Within The James River Basin, Virginia, Joseph L. Noel

Theses and Dissertations

Environmental gradients structure ichthyofaunal communities longitudinally along river networks via the selective filtering of species’ traits. In many instances, these environmental influences have created distinct zones of co-occurring fish species. Zonation studies have most often been conducted with taxonomic data (species x site matrices), but the increasing availability of functional trait data creates an opportunity to build more rigorous understanding of species’ co-occurrence patterns. Notably, zonation studies that use taxonomic data may not reveal the same patterns as studies based on trait data. In this study, we tested for distinct ichthyofaunal zonation in James River Basin, VA using a combination …

Investigating The Role Of Nicotinic Acetylcholine Receptor Agonists In Lung Cancer Progression And Chemosensitivity In The Context Of Treating Chemotherapy-Induced Peripheral Neuropathy, Sarah L. Kyte

Theses and Dissertations

While cancer chemotherapy continues to significantly contribute to the number of cancer survivors, exposure to these drugs can often result in chemotherapy-induced peripheral neuropathy (CIPN), a consequence of peripheral nerve fiber dysfunction or degeneration. CIPN is characterized by sensory symptoms in the hands and feet, such as numbness, burning, and allodynia, resulting in an overall decrease in quality of life. Paclitaxel (Taxol), a microtubule poison that is commonly used to treat breast, lung, and ovarian cancers, has been found to cause CIPN in 59-78% of cancer patients. There is currently no effective preventative or therapeutic treatment for this side effect, …

Association Between Warfarin Adherence Trajectories, Hospitalization Risk, And Healthcare Utilization Among Medicare Patients With Atrial Fibrillation: A Group-Based Trajectory Modelling Approach, Mai Alhazami

Theses and Dissertations

Introduction: Warfarin is the most commonly prescribed drug for stroke prevention among Atrial Fibrillation (AF) patients, especially in older adult populations, but medication nonadherence reduces its effectiveness in clinical practice. Group Based Trajectory Models (GBTM) have been used to identify distinct patterns of adherence behavior related to various medications and understand the patient characteristics associated with each trajectory. The objectives of the study were: 1) Describe trajectories of warfarin adherence among Medicare AF patients, 2) Assess impact of adherence trajectories on AF-related hospitalization, 3) Estimate the AF-related direct costs for each adherence trajectory group.

Methods: We identified elderly AF patients …

Evaluation And Adaptation Of Live-Cell Interferometry For Applications In Basic, Translational, And Clinical Research, Kevin A. Leslie

Theses and Dissertations

Cell mass is an important indicator of cell health and status. A diverse set of techniques have been developed to precisely measure the masses of single cells, with varying degrees of technical complexity and throughput. Here, the development of a non-invasive, label-free optical technique, termed Live-Cell Interferometry (LCI), is described. Several applications are presented, including an evaluation of LCI’s utility for assessing drug response heterogeneity in patient-derived melanoma lines and the measurement of CD3+ T cell kinetics during hematopoietic stem cell transplantation. The characterization of mast cells during degranulation, the measurement of viral reactivation kinetics in Kaposi’s Sarcoma, and drug …

Efficient Information Dissemination In Vehicular Networks With Privacy Protection, Xiaolu Cheng

Theses and Dissertations

Vehicular ad hoc network (VANET) is a key component of intelligent transportation System (ITS). In VANETs, vehicles and roadside units exchange information for the purpose of navigation, safe driving, entertainment and so on. The high mobility of vehicles makes efficient and private communications in VANETs a big challenge.

Improving the performance of information dissemination while protecting data privacy is studied in this research. Meet-Table based information dissemination method is first proposed, so as to improve the information dissemination, and to efficiently distribute information via utilizing roadside units, Cloud Computing, and Fog Computing. A clustering algorithm is proposed as well, to …

Colloidal Synthesis And Photophysical Characterization Of Group Iv Alloy And Group Iv-V Semiconductors: Ge1-Xsnx And Sn-P Quantum Dots, Venkatesham Tallapally

Theses and Dissertations

Nanomaterials, typically less than 100 nm size in any direction have gained noteworthy interest from scientific community owing to their significantly different and often improved physical properties compared to their bulk counterparts. Semiconductor nanoparticles (NPs) are of great interest to study their tunable optical properties, primarily as a function of size and shape. Accordingly, there has been a lot of attention paid to synthesize discrete semiconducting nanoparticles, of where Group III-V and II-VI materials have been studied extensively. In contrast, Group IV and Group IV-V based nanocrystals as earth abundant and less-non-toxic semiconductors have not been studied thoroughly. From the …

The Role Of Vegetation-Topographic Interactions In A Barrier Island System: Island Migration In A Changing Climate, Benjamin Nettleton

Theses and Dissertations

Islands have been characterized based on vegetation and topography as exhibiting different disturbance regimes - reinforcing or resisting. This study had two objectives: quantify barrier island upland migration and vegetation cover change over 32 years (1984-2016), and assess tolerance of two prevalent dune grass species, A. breviligulata, and S. patens to sand burial. Using Landsat imagery from the Virginia Coast Reserve, islands were categorized within the disturbance resistance/reinforcing framework based on dune elevation. Resistant areas were associated with woody cover and low marsh to upland migration while reinforcing areas had low vegetation cover and high rates of migration. System-wide, …

Mass Spectrometry-Based Proteomics Analysis Of Secreted Proteins, Emmanuel K. Cudjoe Jr

Theses and Dissertations

Secreted proteins play important roles in many cellular functions and molecular processes. Because secreted proteins potentially enter the blood stream, they can serve as valuable measures of health and disease useful for disease diagnosis and prognosis, therapeutic target identification, and patient stratification in personalized medicine. Consequently, significant interest exists in secreted protein analysis within complex biospecimens, particularly blood but significant bioanalytical challenges including the wide protein dynamic range >10 orders of magnitude remain. The cellular secretome therefore represents a viable alternative to direct biomarker discovery in biofluids. Finally, cellular systems are amenable to labeling for the production of intact stable …

Housing Status, Patient Characteristics, And Ed Utilization Associated With Medication Prescribing At Ed Discharge Among Homeless And Nonhomeless Adults In Urban Hospitals In The United States, Lauren Cox

Theses and Dissertations

This cross-sectional study used a weighted sample of ED visits contained in the 2010-2015 years of the National Hospital Ambulatory Care Survey-Emergency Department (NHAMCS-ED) dataset. The purpose of this study was to: 1) identify differences in predisposing, enabling, and need characteristics, and ED use and medication prescribing characteristics between homeless and nonhomeless ED users; 2) assess the association between housing status and medication prescribing at ED discharge, and identify variables contributing to the disparity in medication prescribing between homeless and nonhomeless ED users; and 3) assess the predisposing, enabling, need, and ED use characteristics that predict medication prescribing at ED …

Integral Measurement Of Atmospheric Particulate Matter (Pm), Di Liu

Theses and Dissertations

Atmospheric aerosol particles also known as atmospheric particulate matter or particulate matter (PM) are microscopic particles (solid or liquid) suspended in air, which is one of six air pollutants in US air quality standard. PM is classified as coarse particles with diameters between 2.5 to 10 mm, fine particles with a diameter less than 2.5 mm (PM_2.5), and ultrafine particles with the diameter less than 0.1 mm (PM_0.1). Epidemiological studies have already showed the adverse health effects (such as asthma, lung cancer and respiratory and cardiovascular disease) resulted from exposure to the fine and ultrafine particles. …

In Vitro Genetic Code Expansion And Selected Applications, Emil S. Iqbal

Theses and Dissertations

The ability of incorporation non-canonical amino acids (ncAAs) using translation offers researchers the ability of extend the functionality of proteins and peptides for many applications including synthetic biology, biophysical and structural studies, and discovery of novel ligands. Here we describe the three projects where the addition of ncAAs to in vitro translation systems creates useful chemical biology techniques. In the first, a fluorinated histidine derivative is used to create a novel affinity tag that allows for the selective purification of peptides from a complex mixture of proteins. In the second, the high promiscuity of an editing-deficient valine-tRNA synthetase (ValRS T222P) …