Digital Commons Network^™

Linking Microbial Phylogenetic And Functional Gene Diversity To Microbial Mat Ecosystem Function Following Environmental Disturbance, Eva Christine Preisner

Theses and Dissertations

The ability of ecosystems to adapt to environmental perturbations depends on the duration and intensity of change and the overall biological diversity of the system. In this study, a microbial mat ecosystem located on San Salvador Island, the Bahamas was used as a model to examine how environmental disturbance affects microbial community resistance, their protein synthesis potential (PSP), ecosystem function as measured by biogeochemical cycling, community stability, and resilience. This ecosystem experienced a large shift in salinity (230 to 65 g kg-1) during 2011–2012 following the landfall of Hurricane Irene on San Salvador Island. High throughput sequencing and analysis of …

Comparison Of The Performance Of Simple Linear Regression And Quantile Regression With Non-Normal Data: A Simulation Study, Marjorie Howard

Theses and Dissertations

Linear regression is a widely used method for analysis that is well understood across a wide variety of disciplines. In order to use linear regression, a number of assumptions must be met. These assumptions, specifically normality and homoscedasticity of the error distribution can at best be met only approximately with real data. Quantile regression requires fewer assumptions, which offers a potential advantage over linear regression. In this simulation study, we compare the performance of linear (least squares) regression to quantile regression when these assumptions are violated, in order to investigate under what conditions quantile regression becomes the more advantageous method …

Effects Of Diabetes On Ovarian Cancer: Data Analysis And Modeling Study, Claire Belay

Theses and Dissertations

Ovarian cancer has one of the highest mortality rates of all gynecological cancers [13]. Further knowledge of risk factors for the growth of ovarian tumors would be beneficial in both the treatment and prevention of this type of cancer. Previous research has shown a positive correlation between diabetes and prostate tumor growth [22], The first aim of this study was to determine the effect of diabetes of ovarian tumor growth. The second aim was to develop a model to predict ovarian tumor growth based on the microenvironment within a patient’s body. The hypothesis was that there would be a positive …

Correlation Of Aqueous Solubility And Anti-Cancer Activity Of Novel Triazolium And Imidazolium Salts, Jared J. Bies

Theses and Dissertations

Novel triazolium, imidazolium, and benzimidazolium salts are known to possess anti-cancer properties and have potential as cancer therapeutics. This thesis describes the aqueous solubility and the differential activity of N,AT-bis-substituted-l,2,4-triazolium bromide salts and N/N'-bis(naphthylmethyl)imidazolium bromide salts against MDA-MB-468 breast cancer cells and PC-3 prostate carcinomas. Using a microscale technique, the partition coefficient (log P) of each salt was determined. The log P value was explored to determine the bioavailability of each derivative.

On Nature's Prototypes: Character Design And Worldbuilding, Taylor J. Bardon

Theses and Dissertations

Nature’s Prototypes is an ongoing narrative series that blends realism and fiction to create both dialectic plot structures and image sets. For substance, the series utilizes biological inquiries into fields, like ecology, pathology, and bioengineering, to imagine action-centric vignettes, where animalistic to monstrous characters become the predominant actors in a post-dystopian worldscape. Throughout these vignettes, these characters are subjected to the trials and tribulations of the catalysts and flux that are imposed upon them. In the series’ larger scope, these vignettes are sequential events within a larger timeline and an original mythos that delve into the implications and the intrigue …

Effects Of Hiv-1 Tat And Drugs Of Abuse On Antiretroviral Penetration Inside Different Cns Cell Types, Sulay H. Patel

Theses and Dissertations

Human immunodeficiency (HIV) infection can result in neurocognitive deficits in about one-half of infected individuals. Despite excellent systemic effectiveness, restricted antiretroviral penetration across the blood-brain barrier (BBB) is a major limitation in fighting HIV infection within the central nervous system (CNS). Drug abuse exacerbates cognitive impairment and pathologic CNS changes in HIV-infected individuals. This work investigates the effects of the HIV-1 protein, Tat, and drugs of abuse on factors affecting drug penetration into the brain.

Firstly, an in vitro model of the blood-brain barrier was built to study effects of HIV-1 Tat and methamphetamine (Meth) on integrity and function of …

"To Conceive With Child Is The Earnest Desire If Not Of All, Yet Of Most Women": The Advancement Of Prenatal Care And Childbirth In Early Modern England: 1500-1770, Victoria E.C. Glover

Theses and Dissertations

This thesis analyzes medical manuals published in England between 1500 and 1770 to trace developing medical understandings and prescriptive approaches to conception, pregnancy, and childbirth. While there have been plenty of books written regarding social and religious changes in the reproductive process during the early modern era, there is a dearth of scholarly work focusing on the medical changes which took place in obstetrics over this period. Early modern England was a time of great change in the field of obstetrics as physicians incorporated newly-discovered knowledge about the male and female body, new fields and tools, and new or revived …

Toxicological Inhalation Effects Of Metal-Based Nanoparticle Aerosols As Studied By A Portable In Vitro Exposure Cassette, Lynn E. Secondo

Theses and Dissertations

The toxicology of aerosols in occupational settings is often performed through particle collection on a filter followed by reconstitution into cell culture media which can alter the biological effects. Current in vitro exposure systems require additional instruments to control temperature and humidity, making the system bulky and difficult to take to the field. The Portable In Vitro Exposure Cassette (PIVEC) was designed for personal monitoring, characterized using copper nanoparticles, tested with alveolar cells, and set-up for real-time monitoring. Three differently sized copper nanoparticles, 40-800 nm, were dispersed as a dry aerosol and measured gravimetrically and on a number concentration basis …

A Comparison Of The Antimicrobial Efficacy Of Silver Diamine Fluoride And Silver Nitrate: An Ex Vivo Study, Reham M. Alnajjar

Theses and Dissertations

A comparison of the antimicrobial efficacy of silver diamine fluoride and silver nitrate on various cariogenic bacteria: an ex vivo study By: Reham AlNajjar, D.D.S.

A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Dentistry at Virginia Commonwealth University. Virginia Commonwealth University, 2019

Thesis Advisor: William Dahlke, D.M.D., Associate Professor and Chair of Pediatric Dentistry, School of Dentistry

Purpose: The use of silver-based antimicrobials is an emerging method for the treatment of dental caries. In this study, the authors compare the efficacy of the two most prominent silver- based therapeutics, silver diamine …

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 …

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 …

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 …

Periodontal Therapy Improves Oral And Gut Microbiota And Reduces Systemic Inflammation And Endotoxemia In Patients With Cirrhosis, Payam Matin

Theses and Dissertations

Objectives: The aim of this pilot study was to compare the changes in oral and gut microbiota, endotoxemia, and systemic and local inflammatory markers following oral interventions in subjects with and without cirrhosis.

Methods: Study subjects displaying gingivitis or mild/moderate periodontitis were placed into two groups: with cirrhosis (n= 24) and without cirrhosis (n=21). Each subject received nonsurgical periodontal therapy. Serum, stool and saliva samples were collected prior to and 30 days post-therapy and analyzed for stool/saliva microbiome, MELD score, endotoxin and IL-6 levels.

Results: There was no difference in age, gender and the periodontal disease status between groups. At …

Impact Of Aerobic Exercise On Monocyte Subset Receptor Expression And Macrophage Polarization, Anson M. Blanks

Theses and Dissertations

Atherosclerotic cardiovascular disease (CVD) is hallmarked by inflammatory immune activation, particularly by the induction of a response by monocytes. Classical (CD14⁺⁺CD16^-) are anti-inflammatory mediators under homeostatic conditions, while intermediate (CD14⁺⁺CD16⁺) and non-classical (CD14^LowCD16⁺⁺) monocytes promote inflammation following activation. Monocyte activation and functionality is dependent upon receptor expression and ligand production by a variety of cells, including monocytes. Alterations in the expression of surface receptors often have a direct impact upon monocyte function, such as the increased pro-inflammatory cytokine production in response to activation that accompanies elevated CD14 expression …

Discovering Driver Mutations In Biological Data, Yahya Bokhari

Theses and Dissertations

Background

Somatic mutations accumulate in human cells throughout life. Some may have no adverse consequences, but some of them may lead to cancer. A cancer genome is typically unstable, and thus more mutations can accumulate in the DNA of cancer cells. An ongoing problem is to figure out which mutations are drivers - play a role in oncogenesis, and which are passengers - do not play a role. One way of addressing this question is through inspection of somatic mutations in DNA of cancer samples from a cohort of patients and detection of patterns that differentiate driver from passenger mutations. …

Genomic Instability In Severe Congenital Neutropenia, A Leukemia Predisposition Syndrome, Adya Sapra

Theses and Dissertations

Severe congenital neutropenia (SCN) is a rare blood disorder characterized by abnormally low levels of circulating neutrophils. Mutations in multiple genes like neutrophil elastase gene (ELANE) and granulocyte colony stimulating factor receptor (CSF3R) may cause SCN. The treatment of choice for SCN is the administration of granulocyte-colony stimulating factor (G-CSF) which elevates the neutrophil count and hence improves the survival and quality of life. Long term survivorship on G-CSF is however linked to development of MDS (myelodysplastic syndrome)/AML (acute myeloid leukemia). About 70% of MDS/AML patients acquire nonsense mutations affecting the cytoplasmic domain of CSF3R. …

Discrimination, Mental Health, And Preparedness For Aging In Trans(Gender)/Gender-Nonconforming Adults, Richard S. Henry

Theses and Dissertations

This cross-sectional study examined relationships among discrimination, mental health (i.e., depression and anxiety), preparation for aging (i.e., familiarity and planning), social support, death attitudes, and aging anxiety among TGNC adults (N = 154). Neither discrimination nor mental health predicted preparation for aging familiarity or planning. Discrimination did, however, predict both anxiety and depression, although only the non-affirmation subscale was a unique predictor of both. As discrimination and mental health were not a significant predictor of preparedness for aging in the previous regressions, the hypothesized mediation model and subsequent moderated mediation models were not conducted. Additional exploratory multiple regressions were …

Lanthanide-Based Core-Shell Nanoparticles As Multifunctional Platforms For Targeted Radionuclide Therapy And Multimodal Molecular Imaging, Miguel Toro-Gonzalez

Theses and Dissertations

Lanthanide phosphate (LnPO₄) and lanthanide vanadate (LnVO₄) nanoparticles (NPs) are promising platforms for theranostic applications because of their chemical stability, low solubility, low toxicity, and unique luminescence and magnetic properties. Motivated by the high radiation resistance and ability to host actinides of naturally occurring lanthanide-based compounds, LnPO₄ and LnVO₄ NPs were studied as radionuclide carriers for targeted radionuclide therapy using in vivoα-generators, ²²³Ra, ²²⁵Ac, and ²²⁷Th. The implementation of these radionuclides has shown potential for the treatment of micrometastases and solid tumors as well as challenges in the retention of …

Quantitative And Molecular Analysis Of Habituation At The Maize R1 Locus, Robert C. Lindsay

Theses and Dissertations

Epigenetics is the study of heritable changes in phenotypes that are not the result of changes in DNA sequence. Examples of epigenetic affecters include methylation changes, chromatin modifications, transcription factors, and RNA-based changes. The molecular mechanisms behind epigenetic changes are not fully understood. Canalization is the buffering of gene expression against environmental changes over time, while habituation is semi-stable expression change over time due to selection. This work characterized the molecular changes associated with the kernel color changes of the R-sc:86-17pale allele at the maize red color1 (r1) locus to determine if the changes are epigenetic in nature. …

Alternative Splicing Of Cytoplasmic Polyadenylation Element Binding Protein 2 Is Modulated Via Serine Arginine Splicing Factor 3 In Cancer Metastasis, James T. Deligio, James Thomas Deligio

Theses and Dissertations

Our laboratory delineated a role for alternative pre-mRNA splicing (AS) in triple negative breast cancer (TNBC). We found the translational regulator cytosolic polyadenylation element binding protein 2 (CPEB2) which has two isoforms, CPEB2A and CPEB2B, is alternatively spliced during acquisition of anoikis resistance (AnR) and metastasis. The splicing event which determines the CPEB2 isoform is via inclusion/ exclusion of exon four in the mature mRNA transcript. The loss of CPEB2A with a concomitant increase in CPEB2B is required for TNBC cells to metastasize in vivo. We examined RNAseq profiles of TNBC cells which had CPEB2 isoforms specifically downregulated to …

Spatial Learning And Memory In Brain-Injured And Non-Injured Mice: Investigating The Roles Of Diacylglycerol Lipase-Α And -Β., Lesley D. Schurman

Theses and Dissertations

A growing body of evidence implicates the importance of the endogenous cannabinoid 2-arachidonyl glycerol (2-AG) in memory regulation. The biosynthesis of 2-AG occurs primarily through the diacylglycerol lipases (DAGL-α and -β), with 2-AG serving as a bioactive lipid to both activate cannabinoid receptors and as a rate limiting precursor for the production of arachidonic acid and subsequent pro-inflammatory mediators. Gene deletion of DAGL-α shows decrements in synaptic plasticity and hippocampal neurogenesis suggesting this biosynthetic enzyme may be important for processes of normal spatial memory. Additionally, 2-AG is elevated in response to pathogenic events such as traumatic brain injury (TBI), suggesting …

Red-Headed Woodpecker Full Annual Cycle Ecology At Fort A.P. Hill, Virginia, Benjamin Nickley

Theses and Dissertations

The red-headed woodpecker is a primary cavity excavator found throughout the Eastern Deciduous Forest and parts of the Great Plains. Although widespread, the red-headed woodpecker is generally considered uncommon, with patchily distributed populations. Over the past 50 years, this species has experienced precipitous, range-wide declines. The red-headed woodpecker uses a variety of cover types to meet resource needs across the annual cycle, ranging from oak savannas and wetlands, to mature beech forests and urban parks. Given their apparent adaptability to such a wide range of habitats, causes of declines are perplexing. To understand and stem declines, recent studies have focused …

Toward Biologically-Inspired Self-Healing, Resilient Architectures For Digital Instrumentation And Control Systems And Embedded Devices, Shawkat Sabah Khairullah

Theses and Dissertations

Digital Instrumentation and Control (I&C) systems in safety-related applications of next generation industrial automation systems require high levels of resilience against different fault classes. One of the more essential concepts for achieving this goal is the notion of resilient and survivable digital I&C systems. In recent years, self-healing concepts based on biological physiology have received attention for the design of robust digital systems. However, many of these approaches have not been architected from the outset with safety in mind, nor have they been targeted for the automation community where a significant need exists. This dissertation presents a new self-healing digital …

Metalloglycomics: Investigating The Interactions Of Metal Complexes With Heparan Mimetics, Wyatt Johnson

Theses and Dissertations

Proteoglycans containing Heparan Sulfate (HS), a sulfated glycosaminoglycan (GAG), play a major role in the cell signaling process, interacting with many different proteins. HS is over expressed on the surface of many cancer cells. Enzymatic cleavage of HS-GAGs by heparanase causes release of angiogenic growth factors leading to tumor cell migration. Heparanase is also over-expressed in tumors with significant correlation between metastatic potential and heparanase activity. Proteoglycans and their associated enzymes are thus significant drug targets of high biological relevance.

A functional consequence of strong PPC-HS binding has been shown in proof-of-concept studies confirming inhibition of the model pentasaccharide, Fondaparinux, …

Snd1-Targeted Gene Therapy For Hepatocellular Carcinoma, Bryan D. Mckiver

Theses and Dissertations

Staphylococcal nuclease and tudor-domain containing 1 (SND1) is an oncogene for a wide variety of cancers, including hepatocellular carcinoma (HCC). SND1 is a multifunctional protein regulating gene expression of proto-oncogenes and tumor suppressor genes, making SND1 a prime target for developing cancer therapeutics. This notion is especially attributed to HCC as most patients are diagnosed in advanced stages and the therapeutic options available for these patients are severely limited. In this study, we evaluated the therapeutic potential of a replication-defective adenovirus vector delivering SND1 shRNA (Ad.SND1sh) to human HCC cell lines, HepG3, HuH-7, and Hep3B. Adenovirus infection in HCC cells …

Signaling Through Homomeric And Heteromeric Cannabinoid Cb1 Receptors, Guoqing Xiang

Theses and Dissertations

Cannabis (Marijuana) has multiple effects on the human body, such as analgesia, euphoria and memory impairment. Delta-9 tetrahydrocannabinol (D9-THC), the active ingredient in cannabis, binds to cannabinoid receptors, seven-transmembrane G protein-coupled receptors (GPCRs) that mediate a variety of physiological functions. GPCRs were believed to function only in homomeric forms, however, recent findings show that different GPCRs can also form heteromeric complexes that may expand their signaling properties. In this study, we focused on Cannabinoid CB1 receptor (CB1R) heteromers with the mu-opioid receptor (MOR) and the Dopamine type 2 receptor (D2R), respectively. We utilized a variety of techniques, such as the …

A Personal Approach To Landscape: Empathy, Sentiment, And The Environment's Representation In Tumultuous Times, Lauren Hensens

Theses and Dissertations

My work approaches the multitude of personal experience within the landscape, considering its cultural representation, aiming to give the environment agency within these tumultuous times. The following text is a personal narrative, realizing the many lenses through which a landscape can be experienced, including analyses of artists, writers, and musicians who have represented landscape through their own individuality.

Structural Stress And Otherness: How Do They Influence Psychological Stress?, Christine Dewilde

Theses and Dissertations

Background: The Theory of Cultural Distress offers a framework for understanding the potential outcomes in patients who do not receive care that incorporates their cultural beliefs (DeWilde & Burton, 2017).This study represents initial steps in researching the theory byexploring the layering of stressors that place the patient at risk for Cultural Distress. Methods: Utilized aCross-sectional descriptive correlational analysis of intersecting identities (Structural Stressors), ethnicity-related stressors (Otherness) and ethnic-identity (Otherness) to develop understanding of the potential effects of these variables on psychological stress. Independent variables included intersecting identities, perceived ethnic discrimination, concern for stereotype confirmation, own group conformity pressure, and …

Cellular Inhibitor Of Apoptosis Protein2 – A Critical Regulator Of Neuroinflammation, Debolina Dipankar Biswas

Theses and Dissertations

Inhibitors of apoptosis (IAPs) modulate cell death and play critical role in signal transduction that promotes inflammation. Recently, Smac mimetics, which are IAP antagonists, have attracted attention as novel cancer therapeutics. Cellular Inhibitor of Apoptosis 2 (cIAP2), a member of IAP family, positively affects both NF-κB and MAPK activation in response to many inflammatory stimuli. We observed that the lack of cIAP2 ablates LPS-induced neuroinflammation. Also, cIAP2^-/- macrophages demonstrated diminished antigen presentation potential that could contribute to ablated immunity. In addition to these functions, we have previously reported that cIAP2 also regulates the activation of Interferon Regulatory Factor 1 …

Language, Literacy, And Conscientização In American Public Schools, Julie Ward

Theses and Dissertations

Language, Literacy, and Conscientização in American Public Schools synthesizes poststructural language theory to critique literacy teaching and assessment norms in American public schools in order to theorize a pedagogy of racial and economic justice that embraces globalization and immigration. Chapter I creates a theoretical framework for language that rests firmly on both Lev Vygotsky’s and Jacques Lacan’s sociohistorical approach to language acquisition and language use. Mikhail Bakhtin’s work demonstrates the heteroglossic nature of discourse, while Antonio Gramsci politicizes this framework through an understanding of hegemony. Chapter II sketches ethnographic research on teaching practices of various American communities, focusing on ideology …