Digital Commons Network^™

Mechanical Characterization And Non-Destructive Evaluation Of Sicf-Sicm Composite Tubing With The Impulse Excitation Technique, Nathaniel Truesdale

Theses and Dissertations

With growing interest on ceramic fiber reinforced ceramic matrix composites (CMC) for accident tolerant fuel, the need for mechanical characterization of ceramic composite arises. It has been of particular interest to non-destructively evaluate the mechanical performance of these composites. Impulse excitation (IE) is a well-established method for non-destructive mechanical characterization of homogeneous isotropic material of well-defined shapes. In this thesis, impulse excitation technique was applied for non-destructive characterization of composite tube for the first time as far as we know. CMC, when stressed beyond its damage threshold, will experience various forms of structural damage, such as matrix micro-cracking, fiber-matrix debonding, …

Functional Role Of The Homeobox Transcription Factor Six1 In Neoplastic Transformation Of Human Keratinocytes, Maria Hosseinipour

Theses and Dissertations

The homeobox transcription factor SIX1 contributes to both tumor development and progression. Numerous studies have determined that the inappropriate expression of embryonic genes, in particular transcription factors, contributes to carcinogenesis. SIX1 is essential for the development of numerous organs including the auditory and olfactory system as well as the kidney, by promoting proliferation, survival and migration of progenitor cells during embryogenesis. SIX1 has also been shown to increase cancer cell proliferation, survival and invasion. The aberrant expression of SIX1 occurs in numerous adult and pediatric cancers. We have previously determined that our in-vitro model system for HPV16-mediated tumorigenesis shares many …

The Effectiveness Of Self-Regulated Strategy Development For School-Age Children With Hearing Loss, Jessica Rice

Theses and Dissertations

Purpose: The two-fold purpose of this feasibility study was to determine if (a) self-regulated strategy development intervention would improve the writing skills of children with hearing loss and (b) if self-regulated strategy development intervention would improve the reading comprehension skills of children with hearing loss.

Method: One eleven year-old child with bilateral sensorineural hearing loss participated in this single-subject, multiple probe across behaviors design treatment study which examined the effectiveness of using writing intervention to improve reading comprehension in children with hearing loss. The participant completed three seven-week writing interventions focused on narratives, opinion essays, and persuasive essays. Intervention was …

Association Of Gestational Weight Gain During Twin Gestations And Adverse Maternal Outcomes, Kerry Spillane

Theses and Dissertations

Objective: To examine the association between gestational weight gain (GWG) in twin gestations and the odds of adverse maternal outcomes.

Setting and Participants: Study population included 3,081 women with a twin gestation delivered between 23-42 gestational weeks from 19 hospitals across the United States (2002-2008) participating in the Consortium on Safe Labor (CSL) study.

Main Outcomes: Main outcomes of interest included: gestational hypertension, preeclampsia, gestational diabetes mellitus, and cesarean delivery.

Methods: Quantile regression estimated the 25th and 75th percentiles of total GWG, respective of pre-pregnancy BMI and gestational age at delivery, and was used to create our new total GWG …

Preliminary Analysis Of Cyberterrorism Threats To Internet Of Things (Iot) Applications, Bilge Karabacak, Mobolarinwa Balogun, Hayretdin Bahsi

All Faculty and Staff Scholarship

The era of Internet of Things (IoT) being a combination of various networking and computing technologies already in a state of growth that introduces a new age of data aggregation mechanism and ubiquitous connectivity among physical objects. However, the most of the cyber threats still remain unsolved and may create huge impact on our lives. One of the possible major changes in impact landscape is the imminent physical results of cyber threats as IoT technologies enable closer interactions between humans and information systems. Although the cyber threats to critical infrastructures have been highly considered by the cyber security community, the …

Evaluation Of Volumetric Change Of Periapical Lesions After Apicoectomy As A Measure Of Postsurgical Healing Utilizing Cone Beam Computed Tomography, Eshwar Arasu

Theses and Dissertations

The aim of this study was to evaluate whether volumetric changes in persistent periapical lesions can be detected in follow-ups six months to five years after apicoectomy using cone-beam computed tomography. Patients with a previous treatment history of apicoectomy and for whom a pre-surgical CBCT scan was taken between November 2010 and December 2015 were invited to participate in the study. A post-surgical CBCT image of the treated tooth was obtained at the recall visit. Volumetric and linear measurements of periapical lesions on initial and postoperative CBCT images were performed using DiThreshGUI software and two calibrated examiners—a board-certified endodontist and …

Person-Centered Treatment To Optimize Psychiatric Medication Adherence, Natalie Bareis

Theses and Dissertations

Objectives: Adherence to psychotropic medication is poor among individuals with bipolar disorder (BD). To understand treatment experiences and associated adherence among these individuals, we developed a novel construct of Clinical Net Benefit (CNB) using psychiatric symptoms, adverse effects and overall functioning assessments. We tested whether adherence differed across classes of CNB, whether individuals transitioned between classes over time, and whether these transitions were differentially associated with adherence.

Methods: Data come from individuals aged 18+ during five years of the Systematic Treatment Enhancement Program for Bipolar Disorder (STEP-BD). Latent class analysis identified groups of CNB. Latent transition analysis determined probabilities of …

Impact Of School-Based Sex Education On College Students’ Rape Myth Acceptance: An Exploratory Analysis, Erika Carpenter

Theses and Dissertations

Research indicates nearly one-fourth of college women fall victim to sexual assault (Cantor et. al., 2015). Two predictors of high proclivity to rape are endorsement of rape myths and adherence to traditional gender norms (King & Roberts, 2011). Additionally, research shows school-based sex education in the United States presents gender and sexual norms in troubling ways that disproportionately harm women (Kendall, 2013). However, research on sexual assault and rape myths have not examined the impact school-based sex education has on rape supportive attitudes. This study aimed to bridge that gap by using original survey data from undergraduate students at a …

Inhibition Of Oxidative And Conjugative Metabolism Of Buprenorphine Using Generally Recognized As Safe (Gras) Compounds Or Components Of Dietary Supplements, Neha V. Maharao

Theses and Dissertations

This dissertation aimed at developing an inhibitor strategy to improve the oral bioavailability (F_oral) and systemic exposure (AUC_∞) of buprenorphine (BUP) as well as reduce the variability associated with them. Twenty-seven generally recognized as safe (GRAS) compounds or dietary substances were evaluated for their potential to inhibit the oxidative and conjugative metabolism of BUP, using pooled human intestinal and liver microsomes. In both the organs, oxidation appeared to be the major metabolic pathway with a 6 fold (intestine) and 4 fold (liver) higher intrinsic clearance than glucuronidation. Buprenorphine was predicted to show low and variable F …

Testing The Ability Of Two Series Of Models To Predict High School Graduation Status, David T. Marshall

Theses and Dissertations

The purpose of this study was to create and test two series of predictive models aimed at projecting high school graduation status. Secondary data were obtained in partnership with an urban school district. All of the predictor variables included in the models tested in this study were academic and nonacademic variables that were found to be significant predictors of high school graduation in previous empirical work. In the first series of models tested, individual academic and nonacademic variables were tested together along with school-level variables. Eighth and ninth grade variables were tested separately to avoid multicollinearity issues. The second series …

The Influence Of Genetic And Environmental Factors On Quit Attempt In Adolescent And Young Adult Twins, Gladys Langi

Theses and Dissertations

The purpose of this study was to examine the genetic and environmental influences on lifetime quit attempt in three US adolescent and young adult twin samples (N total = 6,322). The study utilized a common-contingent-causal (CCC) model to estimate these factors for lifetime quit attempts, after accounting for the factors for lifetime cigarette use and cigarettes per day. The study also examined age and sex differences, as well as the degree of relationship between these smoking phenotypes. The results demonstrated significant genetic influences for lifetime quit attempts in adolescents and young adults. No sex differences were observed for the contributions …

Abuse-Related Behavioral Effects Of Oxycodone In The Mouse And Their Modulation By Hiv-1 Tat Expression, Rachel M. Enga

Theses and Dissertations

Abuse of prescription opioids has become epidemic and oxycodone is among the most frequently abused of these drugs. Opioid misuse is a risk factor for HIV infection and its chronic use by HIV-infected individuals can be accompanied by worsened progression to AIDS, cellular damage, and behavioral deficits collectively termed “neuroAIDS”. This toxicity is likely attributable, in part, to the interaction of opioids with the neurotoxic HIV-1 Tat protein. The ultimate objective of this dissertation was to characterize the interaction of HIV-1 Tat expression with the abuse-related effects of oxycodone. Physical dependence, drug self-administration, and sensitization are three classes of phenomena …

Profiling Precursor Lipids For Specialized Pro-Resolution Molecules In Platelet-Rich Fibrin Following Fish Oil And Aspirin Intake, Danielle M. Mccormack

Theses and Dissertations

Background: Current research has demonstrated that aspirin and fish oil (EFA) increase plasma levels of specialized pro-resolution molecules (SPMs). This study investigates their effects on SPM precursor pools in platelet rich fibrin (PRF). Methods: Twenty healthy volunteers were randomly assigned to take aspirin; EFA or aspirin and EFA. Four hours later, SPM precursor levels were quantified using combined Liquid Chromatography tandem mass spectrometry. The differences between the groups: Aspirin (yes or no), EFA (yes or no), were analyzed by ANCOVA, testing for group differences after covarying out the baseline value. Results: There were 4 significant interactions, 1 with an aspirin …

Profiling Precursor Lipids For Specialized Pro-Resolution Molecules In Platelet-Rich Plasma Following Fish Oil And Aspirin Intake, Lisa A. Turner

Theses and Dissertations

Background: Unfavorable outcomes following periodontal surgeries can be attributed to impaired resolution mechanisms likely due to decreased levels of specialized pro-resolution molecules (SPM). The current study investigates if SPM substrate pools in platelet-rich plasma preparations (PRP) can be increased by essential fatty acid (EFA) and / or aspirin supplementation. Methods: Nineteen healthy volunteers were randomly assigned to take i) aspirin; ii) EFA; iii) aspirin and EFA. Four hours after intake, the lipid precursor pools in PRP were quantified using combined Liquid Chromatography tandem mass spectrometry (LC-MS/MS) and the data statistically analyzed using ANCOVA. Results: Of the 77 metabolites screened, only …

An Investigation Of Surface Characteristics Of Enamel Treated With Infiltrative Resin: A Scanning Electron Microscopy Study, Danielle E. Easterly

Theses and Dissertations

AN INVESTIGATION OF SURFACE CHARACTERISTICS OF ENAMEL TREATED WITH INFILTRATIVE RESIN: A SCANNING ELECTRON MICROSCOPY STUDY

Danielle E. Easterly, Doctorate of Dental Surgery.

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. 2017.

Director: Dr. Eser Tüfekçi

D.D.S., M.S., Ph.D., M.S.H.A.

Objective: To evaluate the microstructural changes of a resin infiltrant (ICON®, DMG America LLC, Englewood, NJ) after six months of simulated toothbrushing.

Materials and Methods: Ten extracted third molars (n=10) were collected. Artificial white spot lesions were created and resin applied. Environmental SEM …

Three Dimensional Homology Modeling Of Organic Cation Transporter 3 To Identify Structural Elements Mediating Transporter-Substrate Interactions, Hebing Liu

Theses and Dissertations

Organic cation transporters (OCTs) play a pivotal role in the absorption, tissue distribution, and excretion of a diverse array of substances, and currently the nature of the biochemical interactions between substrate and OCTs are unknown. Therefore, identifying which amino acid residues are critical for OCT-substrate interactions is of central importance to understanding and predicting interactions between drugs and OCTs. A three-dimensional (3-D) homology model of human OCT3 was generated using the crystal structure of a high affinity phosphate transporter from Piriformospora indica (PiPT) as template, and putative binding pocket for the prototypical hOCT3 ligand 1-methyl-4-phenylpyridinium (MPP⁺) was identified …

Evaluation Of The Regional Drug Deposition Of Nasal Delivery Devices Using In Vitro Realistic Nasal Models, Mandana Azimi

Theses and Dissertations

The overall objectives of this research project were i) to develop and evaluate methods of characterizing nasal spray products using realistic nasal airway models as more clinically relevant in vitro tools and ii) to develop and evaluate a novel high-efficiency antibiotic nanoparticle dry powder formulation and delivery device. Two physically realistic nasal airway models were used to assess the effects of patient-use experimental conditions, nasal airway geometry and formulation / device properties on the delivery efficiency of nasal spray products. There was a large variability in drug delivery to the middle passages ranging from 17 – 57 % and 47 …

Ethanol Reversal Of Oxycodone Tolerances, Joanna C. Jacob

Theses and Dissertations

Oxycodone is a semi-synthetic opioid originally developed as a safer alternative to morphine. It is commonly prescribed for its pain-relieving effects, but has recently been implicated as a major underlying cause of the current opioid epidemic due to its clinical limitations that include tolerance, dependence and a high abuse liability. Simultaneous consumption of opioids and ethanol has been shown to increase the risk of overdose and death from opioids in opioid-tolerant individuals. We hypothesized that ethanol reversed opioid tolerance and previous studies showed that ethanol reversed morphine tolerance. This dissertation investigated whether ethanol reversed tolerance to other opioids in mice, …

Uncovering The Progress Of Planning For Vulnerability To Sea-Level Rise & Coastal Storms: A Plan Evaluation Of Norfolk, Va & New York City, Eric K. Borchers

Theses and Dissertations

In response to recent storms like Superstorm Sandy and sea-level rise influenced by climate change, cities, particularly those located at the coast, have taken initiative to combat these growing threats with adaptive urban planning. Although civilians residing in susceptible neighborhoods are often the most vulnerable socioeconomically, there has been minimal evidence that planning has accounted for the characteristics of vulnerability. This thesis evaluates the recent planning efforts and vulnerability of Norfolk, VA and New York City to gauge the progress being made toward reducing citizen vulnerability and raising adaptability and preparedness. The most recent peer-reviewed research is consulted to forge …

Interleukin-18 As A Therapeutic Target In Western-Diet Induced Cardiomyopathy, Pratyush Narayan

Theses and Dissertations

Background: Heart Failure (HF) is characterized by impaired cardiac function with symptoms of dyspnea, fatigue and exercise intolerance. Western diet (WD), a diet high in saturated fats and sugars, causes systemic increase in IL-18, a cytokine elevated in HF, which induces abnormal myocardial structure and diastolic dysfunction. IL-18 binding protein(IL-18BP) binds IL-18, preventing the binding to the IL-18-receptor. We investigated a therapeutic intervention using recombinant-murine IL-18BP to improve the WD-induced cardiomyopathy in C57BL/6J mice.

Methods: Echocardiography with pulse-wave Doppler and tissue imaging was performed to assess cardiac function. Oral glucose tolerance test was performed to assess metabolic parameters and IL-18 …

Gomds - Grumpy Old Men Doing Shakespeare; The Comedy Of Errors As Metaphor For Life, Aging, And Building Community, Elizabeth B. Pedersen

Theses and Dissertations

This thesis explores the process of building community over time, through collaboration, to rehearse and produce a portable production of Shakespeare's The Comedy of Errors, looking at the elements of time, trust and age with an ensemble of ten men, all actors over the age of 55. The building of trust over time was vital to the production process and the actors had the time to embody their roles and the language of the play. We look at the questions “why this play,” “why all men?” and “why theatre?” and investigate the physical nature of the play and its …

A Roadmap For Development Of Novel Antipsychotic Agents Based On A Risperidone Scaffold, Urjita H. Shah

Theses and Dissertations

Schizophrenia is a chronic psychotic illness affecting ~21 million people globally. Currently available antipsychotic agents act through a dopamine D₂ receptor mechanism, and produce extrapyramidal or metabolic side effects. Hence, there is a need for novel targets and agents. The mGlu₂/5-HT_2A receptor heteromer has been implicated in the action of antipsychotic agents, and represents a novel and attractive therapeutic target for the treatment of schizophrenia. A long-term goal of this project is to synthesize bivalent ligands where a 5-HT_2A receptor antagonist is tethered to an mGlu₂ PAM via a linker.

The goals of the …

Electronic And Structural Study Of The Reactivity Of Cu+ With Co, H2o, O2, N2 And Their Mixture, Cara M. Frame

Theses and Dissertations

A detailed theoretical study of the gas phase reactivity of copper cation (Cu⁺) with CO, H₂O, O₂, N₂ and their mixture was performed and compared to experimental results to determine the ability of Cu⁺ to act as a low-temperature catalyst for CO oxidation. It was found that Cu⁺ binds strongest to CO, followed by H₂O, N₂, and O₂, strongly interacting with each species until reaching saturation at a maximum of four ligands. It was also found that a single Cu …

Prevalence And Clinical Characteristics Of Teeth Extracted With A Diagnosis Of Cracked Tooth: A Retrospective Study, Riley B. Sturgill

Theses and Dissertations

The body of knowledge that exists regarding cracked teeth is limited. The purpose of this study was to determine the prevalence of cracks among extracted teeth. This retrospective longitudinal cohort study included patients of the Virginia Commonwealth University School of Dentistry that underwent extraction procedures over a 6 year period. The sample consisted of 20,408 patients and 40,870 teeth. Statistical analysis software was used to identify diagnoses of a crack, fracture, or split tooth prior to extraction of the tooth by analyzing the Electronic Health Record (EHR) (axiUm™, Version 6.03.03.1035, Exan Corporation, Vancouver, BC, Canada). There were 3,228 teeth …

Nature Nurtures, Moriah Rhodes

Theses and Dissertations

Richmond, Virginia is defined by our connection to the James River. The James River Park system stretches over 550 acres of natural beauty. The park is broken into 14 different sections from the Huguenot Bridge in the west to a half mile beyond the I-95 Bridge in the east. The James River includes water features that appeal to the young and curious to the most experienced river-adventurer. The James River Park System boasts idyllic shorelines, peaceful meadows, and miles of challenging hiking and biking trails that appeal to the community and guests alike. Every year thousands of people come to …

The Impact Of Objective Quality Ratings On Patient Selection Of Community Pharmacies: A Discrete Choice Experiment And Latent Class Analysis, Julie A. Patterson

Theses and Dissertations

Background: Pharmacy-related performance measures have gained significant attention in the transition to value-based healthcare. Pharmacy-level quality measures, including those developed by the Pharmacy Quality Alliance, are not yet publicly accessible. However, the publication of report cards for individual pharmacies has been discussed as a way to help direct patients towards high-quality pharmacies. This study aimed to measure the relative strength of patient preferences for community pharmacy attributes, including pharmacy quality. Additionally, this study aimed to identify and describe community pharmacy market segments based on patient preferences for pharmacy attributes.

Methods: This study elicited patient preferences for community pharmacy attributes …

Pebbles Is A Girl That Doesn't Know Anything, Grace A. Kubilius

Theses and Dissertations

I am not quite sure how to be a woman. It’s complicated, contradictory and highly surveilled. I make videos, sculptures and wearable objects that attempt to rationalize my female identity. The body is a sustained fixture in my work: as an armature, as an absent actor for constructed environments, as fragment and as the literal inclusion of my image. It is through these various modes of dis/embodiment that I negotiate the complexities of gendered existence. Crumbling ceramic and paper objects, pieced fabric forms, videos, beauty products, and delicate flowers reference splintered narratives and unwieldy terrains. I consider the idea of …

Sustainable Adapted Treatments For Eating Disorders: The Role Of Cultural Adaptation In Prevention, Sarah J. Javier

Theses and Dissertations

Despite demonstrating eating disorder rates equivalent to White women, African American and Asian American women are less likely to seek treatment and are more likely to terminate treatment prematurely. One of the most successful programs for eating disorder prevention has only focused on surface-level cultural adaptations. Prevention literature maintains that deep-structure cultural adaptation (e.g., integrating cultural values and beliefs) can enhance outcomes for ethnic minorities. This dissertation examined the feasibility of Sustainable Adapted Treatments for Eating Disorders (SATED), a pilot intervention that included a culturally- targeted pre-treatment to an eating disorder dissonance-based intervention. A sample of 72 women (ages 18-30) …

Protective Factors In The Association Between Child Sexual Abuse And Telomere Length In Adults, David Sosnowski

Theses and Dissertations

The purpose of the present study was to examine if childhood sexual abuse (CSA) was associated with decreases in mean telomere length (TL), and if social support and/or optimism moderated this association. The study included 99 Caucasian female monozygotic twins, ranging in age from 19-48 (M_age = 30.5, SD = 7.8) at Time 1. Linear mixed effects models were employed to test study hypotheses. Analyses with all participants did not detect an effect of CSA exposure or severity on mean TL, nor were there effects with optimism. However, in analyses that only included women exposed to abuse, increases …

Synchrony And Concordance: A Multilevel Analysis Of The Effects Of Individual Differences During A Co2 Challenge, Rachel E. Wallace

Theses and Dissertations

Emotion theories posit that emotion systems (e.g., behavior, self-report, physiology) should be related when an emotion is being elicited because this serves an adaptive purpose and allows the individual to respond appropriately to the present situation. Oftentimes, this coherent relationship is not found, and research has hypothesized that the type of analyses used and lack of examination of individual differences could be affecting this relationship. Most studies examine the relationship between emotion systems between-subjects when within-subjects analyses may be more appropriate. The present study examined the relationship between self-reported distress (SUDS) and heart rate, and whether trait differences of anxiety …