Digital Commons Network^™

Loneliness And Sleep Disturbance In Older Americans, Sarah C. Griffin

Theses and Dissertations

Loneliness is a risk factor for premature mortality but the mechanics of this relationship remain obscure. A potential mechanism is sleep disturbance. The present study aimed to examine the association between loneliness and sleep disturbance, evaluate loneliness as a risk factor for sleep disturbance and vice-versa, model effects between loneliness and sleep disturbance over time, and evaluate a mediation model of loneliness, sleep disturbance, and health. Data came from the 2006-2012 waves of the Health and Retirement Study, a nationally-representative study of older Americans; participants > 65 were included (n=11,400). Analyses included (i) linear regressions accounting for complex sampling and (ii) …

Indirect Relatedness, Evaluation, And Visualization For Literature Based Discovery, Sam Henry

Theses and Dissertations

The exponential growth of scientific literature is creating an increased need for systems to process and assimilate knowledge contained within text. Literature Based Discovery (LBD) is a well established field that seeks to synthesize new knowledge from existing literature, but it has remained primarily in the theoretical realm rather than in real-world application. This lack of real-world adoption is due in part to the difficulty of LBD, but also due to several solvable problems present in LBD today. Of these problems, the ones in most critical need of improvement are: (1) the over-generation of knowledge by LBD systems, (2) a …

Nanostructured Materials For Photocatalysis, Water Treatment And Solar Desalination, Hiran D. Kiriarachchi

Theses and Dissertations

Maintaining a constant supply of clean drinking water is among the most pressing global challenges in our time. About one-third of the population is affected by the water scarcity and it can only get worse with climate change, rapid industrialization, and the population growth. Even though nearly 70 percent of the planet is covered by water, the consumable freshwater content is only 2.5 percent of it. Unfortunately, the accessible portion of it is only 1 percent. Even so, most of the freshwater bodies are choked with pollution. Considering the vast availability of saline water on the planet and the increasing …

Metaproteomic Investigation Of The Vaginal Microbiome In Pregnancy, Zaneera Hassan

Theses and Dissertations

The development of early diagnostics and prevention strategies for preterm birth is an important global health challenge with the potential to impact over 15 million children annually, by improving health outcomes and reducing economic burden. Advances in microbial sequencing technology have opened the door to 16S rRNA gene survey, whole metagenomics, and whole transcriptomics, providing molecular evidence that the composition of the vaginal microbiome affects pregnancy outcomes in women, particularly those of African descent. A current gap in our molecular level understanding of the vaginal microbiome as it relates to healthy pregnancies is the metaproteome which comprises proteins from both …

Influence Of Environmental Features On Spermatophore Placement In Spotted Salamanders (Ambystoma Maculatum), Megan A. Kuechle

Theses and Dissertations

Successful reproduction in salamanders is driven by behavioral, environmental, and temporal interactions among adults. While much of our understanding of salamander mating systems is based upon either courtship behavior of both sexes or aspects of female choice, the decisions made by males regarding where to place spermatophores is much less quantified. In this study, we mapped male spermatophore placement in the spotted salamander (Ambystoma maculatum) with respect to ecological and spatial locations within a vernal pool complex in Charles City County, Virginia. The overall goal was to use the spatial and ecological placement of spermatophores to determine if …

Tobacco And E-Cigarette Use In Youth With Autism Spectrum Disorders, Nicole R. Higgins

Theses and Dissertations

While there has been an extensive amount of research on tobacco use in children and adolescents, very little has been conducted in children with developmental delays, particularly Autism Spectrum Disorders (ASD). Similarly, research examining newer methods of nicotine use, such as electronic nicotine delivery systems (ENDS; ecigarettes) has not yet been conducted in this population. It has previously been assumed that characteristics commonly observed in youngsters with ASDs serve as protective factors for the initiation of tobacco and ENDS use; however, no studies have identified the variables that contribute to a youngster’s intention to smoke/use ENDS in this vulnerable population. …

Presence And Characterization Of Microplastics In Drinking (Tap/Bottled) Water And Soft Drinks, Mansurat Golden Abdulmalik Ali

Theses and Dissertations

This study investigates the presence of microplastics in human consumable products using 33 samples; Fifteen tap water samples, nine bottled water and nine soft drink samples, collected and purchased in Grand Forks, ND.

Tap water analysis confirm all samples contain microplastics, majority of which were fibres and fragments with 48.6% and 41.8% abundance. The average concentration was 182 mpp/L (range 66 mpp/L – 472 mpp/L) with 2.5 µm – 3 mm size range. Bottled water and soft drinks were also contaminated with microplastics with an average of 101 mpp/L (range 49 mpp/L – 166 mpp/L) and particle size ranging from …

Review Of Sex Determination In Fish And Reptiles And Estimation Of Sex Ratio Heritability In The Common Snapping Turtle, Kyle Hilliard

Theses and Dissertations

Sex-determining mechanisms in fish and reptiles are incredibly diverse. We first review sex-determination in these groups, including approaches that can be used to identify sex-determining genes and the large body of research showing genetic variation for sex ratio in species with temperature-dependent sex determination (TSD). We then show that sex ratio variation among clutches is due to additive genetic effects in one TSD species, the common snapping turtle. This finding contradicts previous claims that non-genetic maternal factors such as yolk steroid hormones are driving sex determination in this species. Heritable variation for sex determination in the snapping turtle may allow …

A Systematic Analysis Of Temporal Trends In The Sit-Ups Performance Of 9,939,289 Children And Adolescents Between 1964 And 2017 Representing 31 Countries, Tori Kaster

Theses and Dissertations

Objective: To estimate national and international temporal trends in the sit-ups

performance of children and adolescents, and to examine relationships between trends in sit-ups performance and trends in health-related and sociodemographic indicators. Methods: Data were obtained in three ways: (a) through a systematic electronic database search of studies reporting on temporal trends in the handgrip strength of apparently healthy 9–17 year-olds, (b) by pearling reference lists, topical systematic reviews and personal libraries, and (c) by examining large country-level fitness datasets suitable to temporal trends analysis. Sample-weighted temporal trends (expressed as percent and standardized trends) were estimated at the country-sex-age level …

The Influence Of Media Bias Perception On Space Publications, Benjamin Robert Raback-Schink

Theses and Dissertations

In an ideal world, scientific research and news would be published and reported through non-bias outlets and readers would view those sources favorably. However, that is an unrealistic expectation of our current society in which many believe that any publication will contain some bias. This thesis aimed to discover three factors on the topic. One was to see whether members of the space community view various news sources as biased, and to what degree they do if so. The second factor was to see how the general public viewed those same sources. These data were then used to compare the …

A Presidential Leadership Process For Higher Education In Small, Rural Institutions And Settings, Teresa Caplinger Spaeth

Theses and Dissertations

A qualitative research study was conducted to explore leadership competencies of presidents of public universities with enrollments of less than 7,000, located in small rural communities and distant locations in the Upper Midwest. The context of higher education is constantly evolving. Internal pressures from faculty and students, as well as external factors such as finances, new technologies, and stakeholder demands play a role in determining the future of academic institutions and the success of their leadership.

Much literature has been written regarding higher education leadership, best practices for success, and future changes that should be made to maintain sustainable institutions, …

Leadership Challenges For Patient Advocates: A Cross Sector Alliance Perspective, Monica Miller

Theses and Dissertations

Innovative and enduring solutions to the myriad of complex social and environmental challenges facing the world today require the shared resources and combined talents of government, nonprofit and for-profit sectors. Interactions between these sectors are called cross sector partnerships (CSPs). An example of CSPs, nonprofit patient advocacy organizations (PAOs) are increasingly entering relationships and collaborations with for-profit pharmaceutical companies (FPPCs). Using a phenomenological approach, this study sought to contribute to the body of knowledge on PAO/FFPC partnerships, as well as broader CSP phenomenon, by exploring how leaders in the field of PAO/FFPC alliances experience collaborations with one another. Three research …

Authentic Leadership, Employee Engagement, And Trust At A Major Logistics Service Company, John C. Mason

Theses and Dissertations

This mixed methods study examined the correlation between authentic leadership among management and employee engagement among unionized hourly workers in a major logistics service company and examined the factor of trust between management and union workers. Within a context of positive organizational behavior, by analyzing and comparing results of the Authentic Leadership Inventory and the Employee Engagement Survey and conducting interviews within a business division, the study determined that there are high levels of authentic leadership, employee engagement, and trust with the district where the study took place. The qualitative part of the study found a very weak negative correlation …

Leading Consciously: Examining Global Leadership Self-Awareness Across Healthcare Executives, Carole N. Bennett

Theses and Dissertations

The well-being of people around the world and in every community depend on healthcare. Yet, exponential shifts in globalization, technology and the environment have destabilized healthcare systems across the globe. Hence, the future of healthcare is forecast to be volatile, uncertain, complex and ambiguous (Porter & Teisberg, 2006). To face current and future challenges, healthcare leaders will be expected to operate consciously and effectively while under extreme pressure. While a number of inter- and intra-personal characteristics and traits are associated with effective leadership through volatility, chief among them is self-awareness (Hernandez, Luthanen, Ramsel, & Ostauke, 2015). Unfortunately, however, no study …

Healthcare Leadership Styles, Competencies And Affinity For Technology In The Digital Era, Zahra Ghafari

Theses and Dissertations

Digital technology has become a continuous disruptor in healthcare research, education, record keeping, and communication, resulting in both opportunities and challenges. The purpose of this study was fourfold, to (a) identify the leadership practices of healthcare executives, (b) measure the attitudes of healthcare leaders toward technology, (c) explore the relation between leadership styles and attitudes toward technology, and (d) examine the relation between demographic factors (gender, age, practice type) and attitudes toward technology. Healthcare leaders in the United States were recruited from different specialties. They were asked to respond to 3 survey instruments: The Multifactor Leadership Questionnaire (MLQ5X), Affinity for …

The Role Of Religiosity, Spirituality, And Creative Arts In The Recovery Process Of Latina Survivors Of Child Sexual Abuse, Bridget M. Vazquez

Theses and Dissertations

The purpose of this study aimed to examine the use and effectiveness of religiosity, spirituality, and creative arts as culturally sensitive forms of coping among adult Latina and/or Hispanic child sexual abuse (CSA) survivors. Research has demonstrated that methods of coping serve as culturally sensitive techniques that help Latinas cope with CSA experiences by fostering feelings of empowerment, pride, and safety (Becker, 2015; Collins, O'Neill-Arana, Fontes, & Osseg, 2014; Ligiero, Fassinger, McCauley, Moore, & Lyytinen, 2009; Marques et al., 2016; Meston, Lorenz, & Stephenson, 2013; Sabina, Cuevas, & Schally, 2012; Sweig, 2000). Despite these findings, these interventions with this specific …

Adaptation Of A Resilience-Oriented Stress Management Intervention For Youth With Type 1 Diabetes, Tamara Michele Rumburg

Theses and Dissertations

Managing type 1 diabetes involves a complex treatment regimen, and often results in increased stress and mental health issues in youth and families as youth enter adolescence. Research indicates that effective management of diabetes-related stress can have a positive impact on both the psychological and physical health of youth and their families. While traditional stress management interventions have aimed to reduce stress through coping, building resilience is a more recent approach to stress management that can be cultivated even in the absence of stress. Interventions specifically aimed at increasing resilience in youth with chronic illnesses have shown promising results; however, …

Best Practices Of Motivation In A Self-Directed Distance Education At A Community College, Hong T. Hoang

Theses and Dissertations

The purpose of the study was to identify predictors that influence a learner’s motivation in a self-directed online business administration course in learning contexts by collecting a sample size population, sample of demographics, and indicators from online students from Business Administration Department at a Southern California Community College. The study explored significant correlation between students’ motivation and learning strategies in a self-directed online business administration course using demographics. Results from this study show demographics including age, education, and ethnicity were statistically significant, but none of the gender differences were statistically significant. This research also explored the educational needs of adult …

Impact On Bacterial Micro-Leakage In Exposed Root Canal Obturation Material In Teeth Irrigated With Different Solutions, Khalifa W. Alhaddad

Theses and Dissertations

Purpose: Determine the timeframe of bacterial penetration that occurs to the apex when obturation material (gutta percha) is exposed to bacteria for a set period of time (45 days) and to determine if bacterial penetration of the obturated root is influenced by the type of irrigant used during the final rinse (17% EDTA vs 2% Chlorhexidine vs full strength 5.25% NaOCl). Methods: Thirty-six extracted teeth, including six controls, were instrumented and irrigated with 5.25% NaOCl followed by a final rinse of either: 17% EDTA, 2% Chlorhexidine, or 5.25% NaOCl, and then obturated. Each root was suspended between two chambers: the …

Evaluation And Comparison Of Periapical Healing Using Periapical Films And Cone Beam Computed Tomography: Post-Treatment Follow Up, Adam S. Polinsky

Theses and Dissertations

Purpose: The purpose of this study was to assess the radiographic changes in periapical status and analysis of healing determined using periapical radiographs (PA) versus cone beam computed tomography (CBCT) pre-operatively and at 3-64 months following endodontic treatment.

Methods: Pre/post treatment radiograph and CBCT scans of patients who had NSRCT, NSReTx, or SRCT from July 2011-December 2018 at VCU Graduate Endodontic clinic were included in this study. Volumetric and linear measurements of periapical lesions on initial and recall PA and CBCT images were performed using three calibrated examiners. Changes and differences in the estimated area from PA to CBCT were …

Frictional Properties Of Novel Bracket Systems: An In-Vitro Study, Stephen M. Haverkos

Theses and Dissertations

Orthodontic brackets undergo resistance during sliding that includes classical friction, binding, and notching. Current bracket systems are hampered by these challenging forces. As a result, the clinician usually needs to apply additional forces to overcome the resistance which increases the risk of root resorption and discomfort for the patient. This study evaluated frictional properties of a novel bracket that had polytetrafluoroethylene (Teflon™) coated rollers in its design. Five types of brackets (n = 10, each), including a passive self-ligating bracket, a traditional ligated bracket, a three-dimensionally printed direct metal laser sintering (DMLS) bracket with and without Teflon™ rollers, and computer …

Transit Access Equity In Richmond, Va, Rachel Jordan

Theses and Dissertations

The purpose of this thesis is to analyze the extent of public transit access equity issues in Richmond, VA. The City of Richmond has an established public transportation network system, and the thesis explores the level of access for urban residents to use existing public transportation services. Technologies and programs have begun to emerge across the United States to help solve transit accessibility challenges. The thesis assesses the level of transit access equity that exists in Richmond and introduces technologies and services that could help improve accessibility and equity. The thesis uses a mixed methods approach that will consist of …

Adaptive Acts: Queer Voices And Radical Adaptation In Multi-Ethnic American Literary And Visual Culture, Michael M. Means

Theses and Dissertations

Adaptation Studies suffers from a deficiency in the study of black, brown, yellow, and red adaptive texts, adaptive actors, and their practices. Adaptive Acts intervenes in this Eurocentric discourse as a study of adaptation with a (queer) POC perspective. My dissertation reveals that artists of color (re)create texts via dynamic modes of adaptation such as hyper-literary allusion, the use of meta-narratives as framing devices, and on-site collaborative re-writes that speak to/from specific cultural discourses that Eurocentric models alone cannot account for. I examine multi-ethnic American adaptations to delineate the role of adaptation in the continuance of stories that contest dominant …

Diuretic And Natriuretic Activity Of Faah Inhibition In The Renal Medulla: A Proposed Role Of Palmitoylethanolamide And Its Regulation By Renal Medullary Interstitial Cells, Sara Dempsey

Theses and Dissertations

Hypertension is a critical public health issue worldwide, and in the United States, it is the leading cause of heart disease, stroke, and kidney failure, contributing to more than 1,100 deaths per day. It is proposed that the renal medulla combats increased blood pressure by releasing a neutral lipid from the lipid droplets of medullary interstitial cells, termed medullipin, which induces diuresis- natriuresis and vasodepression. The renal medulla is enriched with fatty acid lipid ethanolamides including the endocannabinoid anandamide (AEA), palmitoylethanolamide (PEA), and oleoylethanolamide (OEA), along with their primary hydrolyzing enzyme fatty acid amide hydrolase (FAAH). Our lab is investigating …

Let’S Face It: The Effect Of Orthognathic Surgery On Facial Recognition Algorithm Analysis, Carolyn Bradford Dragon

Theses and Dissertations

Aim: To evaluate the ability of a publicly available facial recognition application program interface (API) to calculate similarity scores for pre- and post-surgical photographs of patients undergoing orthognathic surgeries. Our primary objective was to identify which surgical procedure(s) had the greatest effect(s) on similarity score.

Methods: Standard treatment progress photographs for 25 retrospectively identified, orthodontic-orthognathic patients were analyzed using the API to calculate similarity scores between the pre- and post-surgical photographs. Photographs from two pre-surgical timepoints were compared as controls. Both relaxed and smiling photographs were included in the study to assess for the added impact of facial pose on …

The Infectivity Of Naegleria Fowleri Cysts In Vivo And In Vitro, And Mediation Of Encystment By Camp, Anna L. Evdokiou

Theses and Dissertations

The free-living amoeba and causative agent of Primary Amoebic Meningoencephalitis, Naegleria fowleri, has three life stages: the trophozoite, the flagellate, and the cyst. This study examined the ability of the cyst to attach to, excyst upon, and destroy cell cultures grown to confluent monolayers, and to cause Primary Amoebic Meningoencephalitis in a murine animal model. The co-culture of cysts with P388D.1, CHME3, Vero, human nasal epithelial, and rat primary mixed glial cells resulted in destruction of the monolayer of all cell types once the cysts attached and excysted. One day post exposure to cysts, the mixed glial cells exhibited …

Investigation Of The Interactions Between The Dream Complex And Hpv16, Kevin Ko

Theses and Dissertations

According to the American Cancer Society, it has been estimated that in 2019 alone, there will be approximately 53,000 new cases of oropharyngeal cancers. Oropharyngeal cancers are the largest subset of head and neck squamous cell carcinomas (HNSCCs), which are the sixth most common cancer across worldwide populations. They, along with other HNSCCs, fall under a category of cancers known as Human papillomavirus (HPV)-associated cancers, and it has been found that upwards of 70% of these cancers can be attributed to high-risk HPV infections.

Specifically, the high-risk HPV gene, E7, plays a key role in relieving cell cycle repression by …

Design, Synthesis And Pharmacological Characterization Of Potential Mu Opioid Receptor Selective Ligands, Abhishek S. Kulkarni

Theses and Dissertations

Selective Mu Opioid Receptor (MOR) antagonists possess immense potential in the treatment of opioid abuse/addiction. Utilizing the “message-address” concept, our laboratory reported a novel, reversible, non-peptide MOR selective antagonist 17-cyclopropylmethyl-3,14β-dihydroxy-4,5α-epoxy-6β-[(4՛-pyridyl)carboxamido]morphinan (NAP). Molecular modeling studies revealed that the selectivity of NAP for the MOR is because of a π-π stacking interaction of its pyridine ring with the Trp318residue in theMOR. Pharmacological characterization showed that NAP is a P-glycoprotein substrate, thereby limiting its use in the treatment of opioid abuse/addiction. Thus, to modify NAP, we replaced the pyridine ring with its isosteric counterpart thiophene. Isosteric replacement …

Restoration Of Contractile Protein Expression And Colonic Smooth Muscle Function By Hydrogen Sulfide In Dmd Mice, Kulpreet Singh

Theses and Dissertations

Duchenne Muscular Dystrophy (DMD), characterized by the lack of dystrophin, results from a mutation in the Xp21 gene which encodes for the protein dystrophin that links the extracellular matrix to the actin cytoskeleton in skeletal, cardiac and smooth muscle. Slow colonic transit and chronic constipation are common in DMD patients due to the weakening of the abdominal wall muscles and gut smooth muscle. However, the cause of this hypocontractility in DMD patients and the expression of contractile proteins in smooth muscle are unknown. Expression of contractile proteins is regulated by the signaling pathways activated by excitatory (e.g., acetylcholine, ACh) and …

A Genetically Informed Study Of Acute Threat Endophenotypes For Callous-Unemotional Traits, Ashlee A. Moore

Theses and Dissertations

Introduction. Callous-unemotional (CU) traits predict socially debilitating outcomes including Antisocial Personality Disorder and violent crime in adulthood. Despite significant research, the etiology of CU traits is not well understood. This dissertation incorporates genetic, physiological, neuroanatomical, and self-report measures to investigate the etiology of CU traits. Specifically, this project focuses on measures previously found to associate with impaired fear-processing observed in individuals high on CU. Brain morphometry for paralimbic regions of interest (ROIs) and electromyographic facial eyeblink reflex to startle and fear-potentiated startle probes were investigated as potential endophenotypes for CU traits. Methods. Two genetically informative (ages 9-20) twin samples ( …