Digital Commons Network^™

Sol-Gel Assembly Of Metal Nanostructures Into Metallic Gel Frameworks And Their Applications, Xiaonan Gao

Theses and Dissertations

The advent of nanoscience and nanotechnology has sparked many research forefronts in the creation of materials with control over size, shape, composition, and surface properties.^1,2 However, for most of the applications, nanoscale materials need to be assembled into functional nanostructures that exhibit useful and controllable physical properties. Therefore, numerous efforts on the assembly of nanoparticles (NPs) using organic ligands, polymers and polyelectrolytes have been reported.^3,4 However, the interactions between NPs are mediated by intervening ligands, which are detrimental to charge transport and limit the thermal stability. Hence, developing a new method to produce solid …

Potential Treatments For Malformation Associated Epilepsy, Olivia M. Bowles

Theses and Dissertations

Epilepsy has been previously attributed to either increased excitation or decreased inhibition. With this closed frame of mind, modern medicine has been unable to develop a permanent treatment against the mechanisms of epilepsy. In order to treat patients with intractable seizures, especially those caused by developmental malformations, it is essential to understand the entirety of mechanisms that could possibly play a role in the abnormal cortical function. One such developmental malformation is known as polymicrogyria. Epileptogenesis occurs in an area laterally adjacent to this malformation known as the paramicrogyral region (PMR). Past studies have narrowed down the potential cause of …

A Correlational Analysis Of Secondary Data For Factors Influencing Graduation From Adult Drug Court, David N. Masri

Theses and Dissertations

The proliferation of drug courts throughout the world over the last two decades presents an opportunity and a challenge. The drug court approach involves a combination of treatment and judicial supervision which is a diversion from incarceration and/or ‘traditional’ criminal justice supervision. Despite widespread study of drug courts, there is much that researchers still do not know and there is still controversy as to how and why drug courts work. This research study is an examination of secondary data from an urban, mid-Atlantic drug court to attempt to correlate factors that contribute to success (as defined by graduation) in drug …

Allosteric Effects Of G-Protein Coupled Receptor Heteromerization: Relevance To Psychosis, Jason W. Younkin

Theses and Dissertations

G-protein coupled receptors (GPCRs) implicated in disease are the predominant pharmaceutical targets. Growing evidence suggests that GPCRs form homo- and heteromeric complexes, resulting in allosteric functional changes. Ligands targeting one receptor can alter the function of the other receptor or receptors. Knowledge of these functional changes will provide unique opportunities to treat diseases. We examined two GPCR heteromers implicated in psychosis: mGlu2R-5HT2AR and D2R-5HT2AR. Using whole-cell patch clamp, we studied HEK-293 cells stably transfected with mGlu2R and 5HT2AR. Maximal heteromer formation allows inverse agonists to increase the G-protein activity of the opposite receptor, while sub-maximal heteromer formation does not. However, …

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 …

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 …

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) …

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 …

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 …

Perception Of Profile Appearance As Judged By Peers Using 3d Video Imaging, Megan G. Schuler

Theses and Dissertations

The purpose of this study was to investigate the social perceptions of subjects with differing lip position and facial convexity in three dimensions. A 3dMD camera (3dMD, Atlanta, GA) was used to capture 3D images of 9 subjects’ faces. The images were altered to have ideal lip position and ideal convexity, ideal lip position and Class II convexity, Class II lip position and ideal convexity, and Class II lip position and Class II convexity. 400 laypersons rated their perceptions of the subjects’ athletic ability, popularity, leadership, and intelligence on a VAS scale. Subjects with ideal lip position relative to the …

Factors Predicting African American Renal Patients’ Completion Of The Medical Evaluation Process For Kidney Transplantation, Camilla W. Nonterah

Theses and Dissertations

African Americans (AA) are more susceptible to end-stage renal disease (ESRD) for several reasons. Treatment options for patients with ESRD include dialysis therapy and transplantation, with the latter typically producing better outcomes. AA are less likely to complete the medical evaluation process, which requires patients to consult with doctors and undergo a series of tests and examinations. This study sought to determine the factors that predict completion of the medical evaluation for AA ESRD patients using a mixed methods design. Participants consisted of transplant professionals (N=23) recruited from nine transplant centers in the Mid-Atlantic, Mid-Western and Southeastern parts …

Narrative And The Reconfiguration Of The Humanist Subject In Robbe-Grillet, Ballard, And Ligotti, Zachary L. Acosta-Lewis

Theses and Dissertations

This thesis examines the utility of the novels, short stories, critical writing, and generically indistinct work of Alain Robbe-Grillet, J.G. Ballard, and Thomas Ligotti in developing a critique of the contemporary manifestations of liberal humanist social, economic, and political subjectivities. To this end, the concurrence of formal fragmentation and sublime aesthetics in early Gothic fiction models the manner in which narrative structures can appropriate structural tropes of dominant institutions, critically reflecting ideological fracture. Read according to the assemblative approach outlined by Deleuze and Guattari, these authors serve as a productive and incisive response to the hegemony of capitalist territorialization with …

A Two Host Species Stage-Structured Model Of West Nile Virus Transmission, Taylor A. Beebe

Theses and Dissertations

We develop and evaluate a novel host-vector model of West Nile virus (WNV) transmission that incorporates multiple avian host species and host stage-structure (juvenile and adult stages), with both species-specific and stage-specific biting rates of vectors on hosts. We use this model to explore WNV transmission dynamics that occur between vectors and multiple structured host populations as a result of heterogeneous biting rates. Our analysis shows that increased exposure of juvenile hosts results in earlier, more intense WNV transmission when compared to the effects of differential host species exposure, regardless of other parameter values. We also find that, in addition …

Momentum Clinic For Teen And Young Adult Cancer Patients, Merian O'Neil

Theses and Dissertations

This study explores the needs of teen and young adult cancer patients undergoing long-term chemotherapy treatments and the design of an outpatient clinic that accommodates this population’s unique needs. Most teens endure long-term treatments in a pediatric facility targeted primarily for children, while others are treated in adult facilities. Teens have different privacy and social needs than children, and while they are not adults, they are involved in their own treatment decisions, unlike children. The target age group for this study is teens and young adults, ages thirteen to twenty-two. A common theme emerged from research and interviews conducted in …

Cluster Enhanced Nanopore Spectrometry, Amy Chavis

Theses and Dissertations

Nanopore sensing is a label-free method used to characterize water-soluble molecules. Recent work describes how Au₂₅(SG)₁₈ clusters improve the single molecule nanopore spectrometry (SMNS) technique when analyzing polyethylene glycol (PEG). This thesis will further study and optimize the enhancement effect resulting from a cluster’s presence. Additionally, a model describing the interaction between a cluster and PEG is developed to assist in understanding this mechanism of enhancement. This thesis will also discuss expanding the SMNS method to detect peptides, using Au₂₅(SG)₁₈ for enhancement, and adjusting solution conditions to improve the sensitivity of the SMNS system …

Role Of Vav2 In Podocyte Inflammasome Activation And Glomerular Injury During Hyperhomocysteinemia, Sabena Conley

Theses and Dissertations

Hyperhomocysteinemia (hHcys) is a widely known pathogenic factor in the progression of end-stage renal disease (ESRD) and it is also associated with an increased risk for injurious cardiovascular pathologies during ESRD. HHcys is linked to the formation and activation of the NOD-like receptor protein 3 (NLRP3) inflammasome, characterized as a critical early mechanism initiating the inflammatory response. NADPH oxidase (NOX)-derived reactive oxygen species (ROS) mediate the activation of the NLRP3 inflammasome in podocytes in response to elevated levels of homocysteine (Hcys) in vitro and in vivo. However, it remains unknown how NLRP3 inflammasome activation is triggered by NOX. The …

The Care Factor: The Importance Of Using Domain Identification Measures To Identify Stereotype Threat Vulnerability In High School Females, Kimberly Y. Randolph

Theses and Dissertations

Abstract

THE CARE FACTOR: THE IMPORTANCE OF USING DOMAIN IDENTIFICATION MEASURES TO IDENTIFY STEREOTYPE THREAT VULNERABILITY IN HIGH SCHOOL FEMALES.

By Kimberly Y. Randolph, PhD

A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at Virginia Commonwealth University.

Virginia Commonwealth University, 2016.

Major Director: Dr. Charol Shakeshaft, PhD. Professor Department of Educational Leadership

There is a gap that persists in math achievement between high school males and females. Although the NAEP 2015 longitudinal report shows a narrowing in math achievement between males and females there still remains a gap. More importantly, females are …

Investigating The Role Of The Nucleosome Remodeling Factor Ino80 In Development And Nurf In Anti-Tumor Immunity, Zeinab Abdallah Elsayed Ms

Theses and Dissertations

Understanding how an epigenetic regulator such as ATP-dependent chromatin-remodeling complexes modulate processes such as development and/or immune response is essential for our comprehension of cell biology. Deletion of the ATP-dependent chromatin remodeling factor INO80 is known to be embryonically lethal, however, the mechanism is not known. To identify roles for INO80 in mouse early development we generated Ino80 KO mice. Ino80 KO ESCs (Embryonic stem cells) were viable when maintained at ground state pluripotency but fail to differentiate in vitro and in vivo. Gene expression analysis of Ino80 KO early embryos by in situ hybridization showed elevated Bmp4 expression …

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 …

Sulfated Dehydropolymer Of Caffeic Acid For Repair Of Lung Damage And Emphysema, Tien M. Truong

Theses and Dissertations

The complex pathobiologic mechanisms of emphysema are not fully understood, leaving this deadly disease without effective pharmacotherapy for a cure. This project hypothesized that the sulfated dehydropolymer of caffeic acid (CDSO3) exhibits Fe²⁺ chelation-based hypoxia inducible factor-1a (HIF-1a) up-regulatory protective activities against in vitro emphysematous cell death and for in vivo reversal of emphysema induced with SU5416, a vascular endothelial growth factor blocker.

Using in vitro chromogenic competitive inhibition assays, CDSO3 was shown to chelate Fe²⁺ (IC₅₀ of 23 µM), but not Fe³⁺ ions. The trypan blue exclusion and lactate

dehydrogenase assays were then employed to …

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 …

Mechanisms Of Native Shrub Encroachment On A Virginia Barrier Island, Joseph Thompson

Theses and Dissertations

Species composition, temperature, soil nutrients, and leaf area index (LAI) were recorded across three encroaching Morella cerifera thicket edges and three free- standing shrubs on Hog Island, Virginia to characterize the effect of shrub thickets on the plant community and microclimate. Electron transport rate (ETR) was taken on shrub leaves to determine if microclimate benefits M. cerifera physiology. Species richness was lowest inside shrub thickets. Soil water content and LAI were higher in shrub thickets compared to grassland. Soil organic matter, N, and C were higher inside shrub thickets. Summer and fall maximum temperatures were more moderate in shrub thickets …

Adducins Are Negative Regulators Of Migration And Invasion Of Normal Lung Epithelial Cells And Lung Cancer Cells, Parth Hitenbhai Amin, Parth Amin

Theses and Dissertations

Cell migration is an important component of many physiological and pathological processes such as tissue and organ morphogenesis during development, wound healing, inflammatory immune response, and tumor metastasis. The actin cytoskeleton is the basic engine driving cell migration. In the present study, we elucidate the role of an important actin interacting proteins, Adducins, in motility of normal lung epithelium and lung cancer cells. Adducins are the family of cytoskeleton protein capping the fast growing end and facilitating the bundling of actin filaments. Adducins are encoded by the three closely related genes namely alpha (ADD1), beta (ADD2) and gamma (ADD3) Adducin. …

Sense Of Belonging Of Black Students In Stem Majors: A Mixed Methods Study, Lisa Jackson

Theses and Dissertations

The purpose of this research was to examine Black STEM students’ sense of belonging. The researcher also sought to understand what factors most contributed to students’ sense of belonging and whether the involvement in a living learning community or summer bridge program had an effect. An explanatory sequential mixed methods design was used. Participants (N = 89) were administered a revised Psychological Sense of School Membership survey, then were purposively selected to participate in follow-up interviews (N = 8). A principal component analysis, an independent t-test, and a multiple regression analysis were conducted.

Results of the principal …

Understanding And Targeting The C-Terminal Binding Protein (Ctbp) Substrate-Binding Domain For Cancer Therapeutic Development, Benjamin L. Morris

Theses and Dissertations

Cancer involves the dysregulated proliferation and growth of cells throughout the body. C-terminal binding proteins (CtBP) 1 and 2 are transcriptional co-regulators upregulated in several cancers, including breast, colorectal, and ovarian tumors. CtBPs drive oncogenic properties, including migration, invasion, proliferation, and survival, in part through repression of tumor suppressor genes. CtBPs encode an intrinsic dehydrogenase activity, utilizing intracellular NADH concentrations and the substrate 4-methylthio-2-oxobutyric acid (MTOB), to regulate the recruitment of transcriptional regulatory complexes. High levels of MTOB inhibit CtBP dehydrogenase function and induce cytotoxicity among cancer cells in a CtBP-dependent manner. While encouraging, a good therapeutic would utilize >100-fold …

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 …

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 …

Power Analysis In Applied Linear Regression For Cell Type-Specific Differential Expression Detection, Edmund Glass

Theses and Dissertations

The goal of many human disease-oriented studies is to detect molecular mechanisms different between healthy controls and patients. Yet, commonly used gene expression measurements from any tissues suffer from variability of cell composition. This variability hinders the detection of differentially expressed genes and is often ignored. However, this variability may actually be advantageous, as heterogeneous gene expression measurements coupled with cell counts may provide deeper insights into the gene expression differences on the cell type-specific level. Published computational methods use linear regression to estimate cell type-specific differential expression. Yet, they do not consider many artifacts hidden in high-dimensional gene expression …

Methods For Predicting An Ordinal Response With High-Throughput Genomic Data, Kyle L. Ferber

Theses and Dissertations

Multigenic diagnostic and prognostic tools can be derived for ordinal clinical outcomes using data from high-throughput genomic experiments. A challenge in this setting is that the number of predictors is much greater than the sample size, so traditional ordinal response modeling techniques must be exchanged for more specialized approaches. Existing methods perform well on some datasets, but there is room for improvement in terms of variable selection and predictive accuracy. Therefore, we extended an impressive binary response modeling technique, Feature Augmentation via Nonparametrics and Selection, to the ordinal response setting. Through simulation studies and analyses of high-throughput genomic datasets, we …