Digital Commons Network^™

Comparing The Structural Components Variance Estimator And U-Statistics Variance Estimator When Assessing The Difference Between Correlated Aucs With Finite Samples, Anna L. Bosse

Theses and Dissertations

Introduction: The structural components variance estimator proposed by DeLong et al. (1988) is a popular approach used when comparing two correlated AUCs. However, this variance estimator is biased and could be problematic with small sample sizes.

Methods: A U-statistics based variance estimator approach is presented and compared with the structural components variance estimator through a large-scale simulation study under different finite-sample size configurations.

Results: The U-statistics variance estimator was unbiased for the true variance of the difference between correlated AUCs regardless of the sample size and had lower RMSE than the structural components variance estimator, providing better type 1 error …

Optical Spectroscopy Of Wide Bandgap Semiconductor Heterostructures And Group-Iv Alloy Quantum Dots, Tanner A. Nakagawara

Theses and Dissertations

Efficient and robust blue InGaN multiple quantum well (MQW) light emitters have become ubiquitous; however, they still have unattained theoretical potential. It is widely accepted that “localization” of carriers due to indium fluctuations theoretically enhance their efficiency by moderating defect-associated nonradiative recombination. To help develop a complete understanding of localization effects on carrier dynamics, this thesis explores degree of localization in InGaN MQWs and its dependence on well thickness and number of wells, through temperature and power dependent photoluminescence measurements. Additionally, silicon-compatible, nontoxic, colloidally synthesizable 2-5 nm Ge_1-xSn_x alloy quantum-dots (QDs) are explored for potential visible to …

Engineering Icephobic Coatings: Surface Characterization Of Pt Cured Silicones, Sithara Shylaja Nair

Theses and Dissertations

Ice buildup on structures leads to problems that include reduced performance, structural damage and power outages. It is therefore important to limit the energy required for removal of ice from substrates to minimize buildup. Understanding the mechanism of ice adhesion and its dependence on variables like coating thickness, stiffness, surface free energy and morphology is critical for minimizing adhesion. Despite several developments in “icephobic” coatings, which are those that have low ice adhesion, it is important to understand adhesion on the fundamental level to make way for advanced coatings. To do so, a study has been carried out that explores …

Come Fly With Me: Using Amixicile To Target Periodontal Pathogens And Elucidating The Innate Immune Response In Drosophila Melanogaster, Kathryn Sinclair

Theses and Dissertations

Periodontal diseases (PD) affect 46% of American adults over age 30. These diseases cause symptoms including bleeding and swelling of the gums, bone resorption, and tooth loss, that affect quality of life and have a high economic burden. Periodontal diseases are caused by an imbalance in the oral microbiome, from a healthy state that contains anti-inflammatory commensals like Streptococcus gordonii and mitis, to a diseased state that has pro-inflammatory anaerobic pathogens including Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum, and Tannerella forsythia. The latter initiate disease progression in the oral cavity. However, it’s the host immune …

Big Data Visualization Platform For Mixed Reality, Aliakbar Panahi

Theses and Dissertations

The visualization of data helps to provide faster and deeper insight into the data. In this work, a system for visualizing and analyzing big data in an interactive mixed reality environment is proposed. Such a system can be used for representing different types of data such as temporal, geospatial, network graph, and high dimensional. Also, an implementation of this system for four different data types are created. The data types include network data, volumetric data, high dimensional, and spectral data for different mixed reality devices such as Microsoft HoloLens, Oculus Rift, Samsung Gear VR, and Android ARCore were created. It …

Nanopore Thermodynamics Via Infrared Laser Heating, Christopher Angevine

Theses and Dissertations

Single molecule nanopore spectroscopy is a label-free method for characterizing a wide variety of water-soluble molecules. Recently there have been efforts to expand nanopore sensing to new areas of study. Forensic investigators require an easy to deploy method to identify an unknown number of contributors in a solution. Currently there is no easily available method to distinguish between a single or multiple contributor solution of DNA before being processed by more advanced analytical techniques which has led to wasted time and resources increasing the backlog of samples waiting to be processed. In this work we present a new nanopore technique …

Synergy: Game Design + Qur'an Memorization, Sultana Jesmine Moulana

Theses and Dissertations

The rise of digital technology has transformed nearly every part of our daily lives, including the way we learn and memorize. Such transformations raise interesting questions for one of the most long-standing and demanding memorization tasks in the world: the memorization of the Islamic holy book, The Qur’an. For Muslims, The Qur’an is a timeless, sacred text, cradling within its covers many profound images, stories, and parables. Despite rigorous research in the fields of game design and memorization techniques, very little work has been done in combining these two areas of research to create a game-based memorization experience of The …

Non-Medical Use Of Prescription Drugs, Stress, Cultural Orientation, Utilization Of Healthcare, And Protective Factors Among College Students In China, Cheuk Chi Tam

Theses and Dissertations

Background: Non-medical use of prescription drugs (NMUPD) refers to the use of prescription drugs which are traditionally utilized to manage pain or treat psychiatric problems but without a doctor’s prescription. In 2010, an investigation by the Substance Use and Mental Health Services Administration (SAMHSA) revealed that 5.3% of young adults (18 to 25-year-olds) in the United States reported past-month NMUPD. NMUPD has become a growing concern owing to associations with consequences such as college dropout, poor academic achievement, and health jeopardizing behaviors. College students' NMUPD has been well documented in the United States. Limited studies, however, have been conducted among …

Ca2+/Calmodulin-Dependent Protein Kinase Type Ii (Camk-Ii) Is Required For Hematopoietic Stem Cell Specification, Camden E. Kurtz

Theses and Dissertations

Ca2+/Calmodulin-dependent protein kinase type II (CaMK-II) is a Serine/Threonine protein kinase that is activated by Ca2+ and Calmodulin to phosphorylate substrates involved in myriad developmental processes. This project implicates CaMK-II in specification of HSCs, and zebrafish provide an ideal embryonic model to study hematopoiesis. Zebrafish genetic manipulation was achieved through: incubation in chemical inhibitors; injection of notochord-targed WT and DN CaMK-II constructs with Transposase; and injection of camk2g1 translation-blocking morpholino antisense oligonucleotide (MO). Whole-mount in situ hybridization (WISH) and immunolocalization on zebrafish embryos allowed visualization of key HSC markers and pathway components that implicated CaMK-II in the specification of HSCs. …

Examining Health Behaviors In College Students With And Without Chronic Conditions, Duc-Thi J. Barsell

Theses and Dissertations

Many college students are in a developmental period in which they are transitioning from pediatric to adult health care. This time period can be challenging for all college students and especially for students with a chronic condition. The current study investigated the association between various health-related factors (health locus of control [HLOC], health literacy, health self-efficacy, and health-related quality of life [HRQOL]) and health behaviors in college students, as well as the moderating effect of having a chronic condition on those associations. These health behaviors were further operationalized as healthy lifestyle behaviors (preventative and wellness behaviors, dietary behaviors, physical activity) …

Recovery From Design, Cassandra J. Ellison

Theses and Dissertations

Through research, inquiry, and an evaluation of Recovery By Design, a ‘design therapy’ program that serves people with mental illness, substance use disorders, and developmental disabilities, it is my assertion that the practice of design has therapeutic potential and can aid in the process of recovery. To the novice, the practices of conception, shaping form, and praxis have empowering benefit especially when guided by Conditional and Transformation Design methods together with an emphasis on materiality and vernacular form.

Role Of Mir-155 And Mir-146a In Mast Cell Function, Amina Abdul Qayum

Theses and Dissertations

Mast cells are resident immune cells abundantly found in the tissue at the host-environment interface, where they play a critical role in inflammatory allergic responses. Mast cell responses may be regulated by the cytokine milieu at the site of inflammation. Recent studies have revealed microRNAs to be important in altering cytokine signaling in immune cells. Here, we demonstrate for the first time that IL-10 and IL-33 induce miR-155 and miR-146a, respectively, to alter mast cell functions. We report that IL-10 enhanced IgE induced activation of mast cells. IL-10 effects are dependent on Stat3 activation, which elicits miR-155 expression, resulting in …

The Experiences And Perceptions Of Behavioral Factors That Contribute To Successful Weight Loss In Male Bariatric Patients, Stephen P. Sowulewski

Theses and Dissertations

The purpose of this study was to examine the experiences and perceptions of behavioral factors that contribute to successful weight loss in male bariatric patients. By analyzing participant experiences and perceptions, this study contributes to a better understanding of which factors are most important in the postoperative phase of gastric bypass in males owing to successful weight loss. Although there is a tremendous amount of quantitative research within the bariatric population, there is a significant gap within the qualitative literature as it relates to male outcomes. As such, by conducting interviews with 10 postoperative male gastric bypass patients, this study …

Three Measures Of Coping In Video Games (Civ-Iii): The Development, Construct Validation, And Profile Analysis Of The Civ-Iii, Chelsea M. Hughes

Theses and Dissertations

Video games provide a competitive, goal-oriented environment. They involve individuals who often seek intentionally to frustrate their opponents’ goals. The gaming community is made up of players who vary in their interpersonal style, learning histories, and skill levels. In this rich and dynamic environment, stress is a common experience. Given the prevalence of gameplay in the population and the frequency of gameplay among gamers, it is important to examine coping responses to stressors, particularly maladaptive ones. The present research entails three studies. In Study 1, I use exploratory factor analyses to develop three scales purported to measure maladaptive coping strategies …

Favorability Of Financial And Nonfinancial Performance Measures And Analysts' Recommendations, Thomas F. Lewis Jr

Theses and Dissertations

This study investigates the extent to which sell-side analysts make full use of available financial and nonfinancial information signals in formulating stock recommendations. Prior research shows that investors rely strongly on sell-side analysts’ recommendations and that sell-side analysts pay considerable attention to nonfinancial measures in making their decisions. However, prior research has primarily focused on the mere presence of nonfinancial measures and not the extent to which the direction of such measures (i.e. favorability) is associated with firm value, or assessed the extent to which any interaction between financial measures and the direction of nonfinancial measures may influence analysts in …

Discovery And Characterization Of Bile Acid And Steroid Metabolism Pathways In Gut-Associated Microbes, Spencer Harris

Theses and Dissertations

The human gut microbiome is a complex microbial ecosystem residing in the lumen of our gastrointestinal tract. The type and amounts of microbes present in this ecosystem varies based on numerous factors, including host genetics, diet, and environmental factors. The human gut microbiome plays an important role in normal host physiological functions, including providing energy to colonocytes in the form of short-chain fatty acids. However, gut microbial metabolites have also been associated with numerous disease states. Current tools for analyzing the gut microbiome, such as high-throughput sequencing techniques, are limited in their predictive ability. Additionally, “-omic” approaches of studying the …

'The Writing Writes Itself': Deleuzian Desire And The Creative Writing Mfa Degree, Ginger Walker

Theses and Dissertations

This post-qualitative inquiry project investigated subjectivity (sense of self) among graduates of creative writing Master of Fine Arts (MFA) programs. The project asked how subjectivity is involved in the creative writing process and how that process fuels further writing after a creative piece (such as the MFA thesis) is completed. A post-qualitative, thinking-with-theory approach was used to explore the role of subjectivity among four anonymous graduates of creative writing MFA programs who provided writing samples describing their creative writing processes. Following the thinking-with-theory approach, the data were analyzed using Deleuze and Guattari’s theory of productive desire. Study findings are presented …

Distant Electric Vision: Cultural Representations Of Television From “Edison’S Telephonoscope” To The Electronic Screen, Ivy Roberts

Theses and Dissertations

Do inventions that exist only on paper have less credibility than functional technologies? How has the meaning and significance of audiovisual media and technology changed over time? This dissertation examines historiography and methodology for media history, arguing for an interdisciplinary approach. It addresses methodological issues in media history—media in transition, media archaeology, and film history—through an examination of television’s speculative era. It tackles moving-image history through an historical investigation of Victorian and Machine age “television”.

Because the concept and terminology of “television” changed dramatically during this period, I use the phrases “distant electric vision” and “seeing by electricity,” to define …

Educational Predictors For Postsecondary Living Status, Irina Cain

Theses and Dissertations

This study was performed as the result of gaps in the literature in the area of transition to independent living (IL) using secondary data from the National Longitudinal Transition Study 2 (NLTS-2). Its findings identify individual, skills, family, and school factors that predict postsecondary living status and moderators of the relationships between predictors and the outcome. Specifically, results indicated the following factors as predicting postsecondary living status: individual factors (ethnicity and disability label), skills (self-care, functional mental, personal autonomy, self-realization, and social), family factors (parental expectations and parental involvement in school), and school factors (student’s role in transition planning and …

Upper Elementary Reading Instruction In The Age Of Accountability: Balancing Best Practices With Pressures To Achieve On High-Stakes Tests, Christina H. Saunders

Theses and Dissertations

The present study identifies reading instructional practices used in upper elementary classrooms during the age of high-stakes test accountability and compares reading practices among schools of varying accreditation status and socio-economic status (SES). The current study partially replicates and extends a study conducted by Baumann, Hoffman, Duffy-Hester, and Ro in 2000. The Baumann et al. (2000) study provides a frame of reference to compare instructional practices prior to high stakes testing with those used in the current high stakes testing environment. Third- through fifth-grade teachers in seven school districts in central Virginia were asked to complete an electronic survey. Descriptive …

Predictors Of Barriers To Psychosocial Treatment For African American Families Of Children With Adhd, Stephanie A. Wilson

Theses and Dissertations

African American families of youth with Attention-deficit/hyperactivity disorder (ADHD) traditionally have lower rates of ADHD treatment compared to nonminority groups. These treatment disparities underscore the importance of better understanding the barriers to treatment for these families. Therefore, in a sample of 67 African American caregivers of children with ADHD, the current study examined (1) factors that predict barriers to treatment for African American families of children with ADHD and (2) whether caregiver impairment mediates comorbid behavior problems and barriers to treatment for African American youth with ADHD. Analyses revealed that caregiver impairment predicted barriers to treatment and mediated the relationship …

Sticking To The Recipe: How Do Adherence And Differentiation To A Cbt Protocol Affect Client Outcomes In Youths With Anxiety?, Ruben G. Martinez

Theses and Dissertations

Objective: Understanding the pathways through which treatments work to change symptom and diagnostic outcomes is important to the development and delivery of evidence-based treatments. This study assessed the extent to which adherence (therapist’s delivery of prescribed therapeutic interventions) and differentiation (therapist’s delivery of non-prescribed therapeutic interventions) to Coping Cat, a CBT program, affected client symptom and diagnostic outcomes. Method: The Therapy Process Observational Coding System for Child Psychotherapy – Revised Strategies Scale (McLeod et al., 2015) was used to characterize therapeutic interventions delivered within and outside of the Coping Cat program with youths aged 7-15 receiving treatment in one efficacy …

Provider Appearance: A Survey Of Guardian And Patient Preference, Joshua Westphal

Theses and Dissertations

Purpose: To understand guardian and child preferences for the appearance of their pediatric dentist. This was a cross-sectional descriptive study using survey methodology with patients and parents that attended the VCU Pediatric Dental clinic.

Methods: A total sample of 100 guardians and 97 pediatric patient participants completed the computer-based questionnaire. Four subjects were asked to pose for photographs wearing various combinations of attire (professional, casual, white coat, scrubs).

Results: Among guardians, 56% reported preferring a provider in scrubs, with white coat the second most preferred attire (39%) for their children. For pediatric patients, scrubs were still most often selected, …

Hub Proteins, Paralogs, And Unknown Proteins In Bacterial Interaction Networks, Neha Sakhawalkar

Theses and Dissertations

Proteins are the functional units of cells. However, a major portion of the proteome does not have a known functional annotation. This dissertation explores protein -protein interactions, involving these uncharacterized or unknown function proteins. Initially, protein – protein interactions were tested and analyzed for paralogous proteins in Escherichia coli. To expand this concept further and to get an overview, protein – protein interactions were analyzed using ‘comparative interactomics’ for four pathogenic bacterial species including Escherichia coli, Yersinia pestis, Vibrio cholerae and Staphylococcus aureus. This approach was used to study unknown function protein pairs as well as to …

Role Of The Pediatric Dental Provider In Human Papillomavirus (Hpv) Education, Meredith L. Dugoni

Theses and Dissertations

Purpose: This study investigates knowledge about HPV and examines if pediatric dental providers should include HPV education for guardians of patients 10-18 years.

Methods: Legal guardians of 10-18 year-old patients of the Virginia Commonwealth University Pediatric Dental Clinic were enrolled in this prospective cohort study. Participants completed a baseline survey, were provided HPV education, completed an initial follow-up survey, and then completed a 6-month follow-up survey.

Results: A total of 54 participants completed the baseline and initial follow-up surveys and 17 completed the 6-month follow-up survey. The average number of correct responses was 3.4 of 6 knowledge questions, which significantly …

A Sensitivity Analysis For Relative Importance Weights In The Meta-Analytic Context: A Step Towards Narrowing The Theory-Empiricism Gap In Turnover, James G. Field

Theses and Dissertations

Turnover is one of the most important phenomena for management scholars and practitioners. Yet, researchers and practitioners are often frustrated by their inability to accurately predict why individuals leave their jobs. This should be worrisome given that total replacement costs can exceed 100% of an employee’s salary (Cascio, 2006) and can represent up to 40% of a firm’s pre-tax income (Allen, 2008). Motivated by these concerns, the purpose of this study was to assess the predictive validity of commonly-investigated correlates and, by extension, conceptualizations of employee turnover using a large-scale database of scientific findings. Results indicate that job satisfaction, organizational …

Bridging The Empathy Gap: Effects Of Brief Mindfulness Training On Helping Outgroup Members In Need, Daniel R. Berry

Theses and Dissertations

Witnessing others in need can be felt similarly to experiencing it oneself (empathy) and motivates assistance of those in need (prosocial action). It is well-documented that empathy can occur automatically, but when those in need are not members of a social ingroup, empathy and prosocial action are undermined. One major ingroup—outgroup division in American and in other countries is based on race. Although most condemn racial discrimination, empathy and prosocial action are often lower, however unintentionally, in interracial contexts. In light of this empathy gap, it is important to identify psychological factors that could bolster empathy and prosocial action toward …

Virginia's Instructional Technology Resource Teacher Program: Ten Years Later, What We Know, -Where Do We Need To Go?, Cherise A. Hodge

Theses and Dissertations

VIRGINIA’S INSTRUCTIONAL TECHNOLOGY RESOURCE TEACHER PROGRAM: TEN YEARS LATER, WHAT WE KNOW, WHERE DO WE NEED TO GO?

By Cherise Ann Hodge, PhD

A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of

Philosophy at Virginia Commonwealth University.

Virginia Commonwealth University, 2017

Director: Dr. Whitney Newcomb,

Professor, Educational Leadership

In 2004, Virginia’s Department of Education (VDOE) identified the need for technology integration in instruction to meet the needs of the 21^st century student. For this to happen effectively, Virginia legislators authorized and funded an instructional position, the Instructional Technology Resource Teacher (ITRT), for each …

“Confederate Soldiers In The Siege Of Petersburg And Postwar: An Intensified War And Coping Mechanisms Utilized, 1864- Ca. 1895”, Matthew R. Lempke

Theses and Dissertations

This thesis crafts a narrative about how Confederate soldiers during the siege of Petersburg experienced an intensified war that caused them to refine soldierly coping mechanisms in order to endure. They faced increasing deprivations, new forms of death, fewer restrictions on killing, dwindling fortunes, and increased racial acrimony by facing African American soldiers. In order to adjust, they relied on soldierly camaraderie, Southern notions of honor, letter writing, and an increasingly firm reliance on Protestant Christianity to cope with their situation. Postwar, these veterans repurposed soldierly coping mechanisms and eventually used institutional support from their states. Camaraderie, honor, literary endeavors, …

How Master Teachers Conceptualize Student Engagement: A Comparison Of Theoretical And Practitioner Perspectives, Andrew D. Baker

Theses and Dissertations

Over the past twenty years, an increasing amount of research has been devoted to the study of student engagement within the field of educational psychology. This led to a growing body of research touting the benefits of engaged learning—from increased student achievement to more positive school experiences for learners. However, the literature is characterized by competing theoretical frameworks and multiple definitions of the construct of student engagement. Additionally, few works seek to capitalized on the expertise of classroom teachers to hone and develop what is known about engagement from the theoretical perspective.

The current study used qualitative methodology to observe …