Medicine and Health Sciences Commons^™

Psychometrically Equivalent Thai Monosyllabic Word Recognition Materials Spoken By Male And Female Talkers, Chela Williams

Theses and Dissertations

The purpose of this study was to develop, digitally record, evaluate, and psychometrically equate a set of Thai monosyllabic word lists to use in the measurement of word recognition ability. A native male and female talker from Thailand, who were judged to have a standard Thai dialect, participated as talkers in digitally recording familiar Thai monosyllabic words. Twenty native Thai participants were used as subjects to determine the percentage of correct word recognition for each word at 10 intensity levels ranging from --5 to 40 dB HL in 5 dB increments. The 200 words with the highest raw scores were …

The Relationship Among Emotion Understanding, Language, And Social Behavior In Children With Language Impairment, Lara Lynn Goldie

Theses and Dissertations

This study examines the influence of emotion understanding, language, and working memory on reticence and prosocial behavior in children with language impairment (LI). The Comprehensive Assessment of Spoken Language (CASL; Carrow-Woolfolk, 1999) and The Universal Nonverbal Intelligence Test (UNIT; Bracken & McCallum, 2003) were administered to 39 children with LI and 39 typical age-matched peers. A nonword repetition task and two tasks measuring emotion understanding were also administered. Each of the participant's classroom teachers completed The Teacher Behavioral Rating Scale (TBRS; Hart & Robinson, 1996). Structural equation modeling was used to estimate models of the data using a maximum likelihood …

Creation Of A Mouse With A Humanized Fpgs Gene Compatible With Normal Development, Linying Xie

Theses and Dissertations

Abstract: Folylpoly-γ-glutamate synthetase (FPGS) catalyzes the formation of polyglutamate forms of the reduced folates and antifolates such as methotrexate (MTX) and pemetrexed; this allows the retention of folates and antifolate cancer drugs inside the cell. The enzyme activity of FPGS is essential for cell proliferation and survival. The mouse fpgs gene contains two promoters spaced 10 kb apart which are activated in a tissue-specific manner. The upstream promoter (P1) and exons A1a and A1b are used in some differentiated tissues, mainly liver and kidney, whereas the downstream promoter (P2) and exon 1 are used in rapidly dividing cells. In contrast, …

In Vitro Models For Inhaled Corticosteroid (Ics) Aerosols: A Study Of Their Biopharmaceutics And Pharmacology, Deepika Arora

Theses and Dissertations

Lung cellular disposition and anti-inflammatory pharmacology of inhaled corticosteroids (ICSs) is complex, comprised of a cascade of aerosol deposition and dissolution, followed by cellular uptake for local pharmacological action. This project hypothesized that the kinetics of dissolution for certain ICS aerosols generated from inhaler products were kinetically rate-determined for their cellular uptake and local pharmacological action. A novel dissolution testing system was developed to determine the dissolution kinetics for the ICS aerosols. A total of 5 ICSs aerosols generated from 6 inhaler products were collected in 2.1-3.3 or 4.7-5.8 µm of aerodynamic diameters at 0.7-19.8 µg on filter membranes by …

The Expression And Function Of Phosphacan/Rptpβ In Adaptive Synaptogenesis After Traumatic Brain Injury, Janna Harris

Theses and Dissertations

Traumatic brain injury (TBI) affects 1.5 million Americans annually and is a major health concern. Increasing evidence suggests that the brain extracellular environment regulates plasticity and synaptic recovery following TBI. Here we have focused on phosphacan/RPTPβ, an alternatively spliced group of chondroitin sulfate proteoglycans which are prominent within the mature brain extracellular matrix (ECM). Previous studies show that phosphacan/RPTPβ influences neuronal migration, adhesion, neurite outgrowth, and morphogenesis. However, our understanding of how these important ECM components are involved in recovery from brain trauma remains unclear. In the present study, we used unilateral entorhinal cortex lesion (UEC), a model which induces …

Selective Non-Peptide Mu-Opioid Receptor Antagonist: Design, Synthesis And Biological Studies, Lindsey Aschenbach

Theses and Dissertations

There are currently many opioid agonists available for clinical use as analgesics. However, many of these opioid agonists have notorious side effects including respiratory depression and may lead to addiction and dependence. Problems associated with these opioid agonists are determined to come from their interactions with the mu-opioid receptor. Opioid antagonists, such as naltrexone, have shown to aid in the treatment of opioid addiction. Although naltrexone has high affinity to the mu-opioid receptor, it lacks selectivity. Novel selective mu-opioid receptor antagonists were designed based on the identification of important pharmacophore elements in several known mu-opioid receptor agonists and antagonists. These …

Discovery And Initial Characterizations Of Neurofascin 155 High And Neurofascin 155 Low, Anthony Pomicter

Theses and Dissertations

This thesis contains the findings from four years of research regarding an oligodendrocyte protein named neurofascin 155. The role of this protein in maintaining adhesion between the myelin sheath of oligodendrocytes and the axons of neurons has become well established in recent years and the research presented here has revealed that while western blots have previously shown one protein/band representing neurofascin 155, there are two proteins/bands. These two proteins have been named neurofascin 155 high and neurofascin 155 low due to their previous inclusion in the single band. The work leading up to their discovery, findings, and the relevance of …

Interneuron Subtypes Are Differentially Altered In Malformed, Epileptogenic Cortex, Amanda George

Theses and Dissertations

The propensity for seizures in patients with epilepsy is due to underlying cortical hyperexcitability, the mechanisms of which are poorly understood. Particularly difficult to treat are patients with developmental malformations of cortex. Using the freeze-lesion rat model of one such malformation, polymicrogyria, we identified, in lesioned cortex, alterations in specific interneuron subpopulations that may promote hyperexcitability. Previous studies demonstrate increased excitatory input to the paramicrogyral region. An increase in the frequency of spontaneous excitatory postsynaptic currents (sEPSCs) recorded from pyramidal cells has also been shown. We report an increase in sEPSCs recorded from one subtype of interneuron, the low threshold-spiking …

Analysis Of The Mechanism Of Transferrin-Iron Acquisition By Neisseria Gonorrhoeae, Noto Jennifer Mcmillan

Theses and Dissertations

Neisseria gonorrhoeae is an obligate human pathogen that requires iron for its survival within the host. N. gonorrhoeae expresses high-affinity iron acquisition systems to acquire iron from host iron binding proteins. The gonococcal transferrin-iron uptake system is composed of two transferrin binding proteins, TbpA and TbpB. TbpA is a TonB-dependent, outer membrane transporter, while TbpB is a surface-exposed lipoprotein. Unlike TbpA, TbpB is not required for transferrin utilization, but makes the process more efficient. The precise mechanism by which TbpA and TbpB function to mediate transferrin-iron uptake has not been fully characterized. However, the mechanism of iron acquisition from transferrin …

Identification Of Pharmacological And Molecular Mechanisms Involved In Nicotine Withdrawal, Kia Jackson

Theses and Dissertations

Tobacco dependence is the leading cause of preventable death in the United States. Despite currently available smoking cessation therapies, there is a high rate of relapse in smoking among those attempting to quit. While the somatic signs of nicotine withdrawal (insomnia, increased appetite, weight gain) contribute to the continuation of smoking behavior, it has been hypothesized that the affective signs (depression, anxiety, craving, irritability) are greater motivators of relapse and continued tobacco use. There are few studies that assess the molecular and receptor-mediated mechanisms of nicotine withdrawal; therefore, our studies focus on identifying the nicotinic acetylcholine receptor (nAChR) subtypes and …

Identification Of Virulence Determinants For Streptococcus Sanguinis Infective Endocarditis, Lauren Turner

Theses and Dissertations

Streptococcus sanguinis is the second most common causative agent of bacterial infective endocarditis (IE). Risk of S. sanguinis IE is dependent on pre-disposing damage to the heart valve endothelium, which results in deposition of clotting factors for formation of a sterile thrombus (referred to as vegetation). Despite medical advances, high mortality and morbidity rates persist. Molecular characterization of S. sanguinis virulence determinants may enable development of prevention methods. In a previous screen for S. sanguinis virulence determinants by signature-tagged mutagenesis (STM) an attenuated mutant was identified with a transposon insertion in the nrdD gene, encoding an anaerobic ribonucleotide reductase. Evaluation …

The Relationship Between Perceived Personal Risk Of Getting Prostate Cancer And Prostate-Specific Antigen (Psa) Screening, Yeatoe G. Mcintosh

Theses and Dissertations

Abstract Title: The Relationship between Perceived Personal Risk of getting Prostate cancer and Prostate-Specific Antigen (PSA) Screening Yeatoe G. McIntosh, MPH Candidate Advisor: Emmanuel Anum, MBChB, MPH, PHD Preceptor: Emmanuel Anum, MBChB, MPH, PHD Background: Prostate cancer is one of the most common cancer diagnoses in the United States. The American Cancer Society estimates that in 2008 28,660 deaths would be attributed to prostate cancer, projecting it to be the leading cause of cancer deaths in U.S. men. Despite the potential threat this cancer presents to men and the potential for improved disease outcomes from early detection, guidelines for screening …

Modeling Pure Vasogenic Edema In The Rat Brain, Charles Nottingham

Theses and Dissertations

Targeted drug delivery to the brain is difficult to achieve using conventional techniques, largely due to the blood-brain barrier’s (BBB) impediment to drug diffusion into the brain parenchyma. In response, development of convection-enhanced delivery (CED) offers the ability to circumvent the BBB and target specific areas of the brain. Predictability of infusate movement in pathological brain states during CED will maximize the effectiveness of this treatment, and therefore modeling of infusate movement must be characterized. Previous work from our lab effectively modeled CED in rats using the middle carotid artery occlusion model of cytotoxic edema. However, previous models examined for …

Physiological And Molecular Characterization Of Genetic Competence In Streptococcus Sanguinis, Alejandro Rodriguez

Theses and Dissertations

The ability of bacteria to assimilate free DNA from the environment is known as competence. Though many studies have focused on competence regulation in Streptococcus pneumoniae and Streptococcus gordonii, Streptococcus sanguinis has yet to be examined. Physiological characterization of competence in S. sanguinis strain SK36 and its comC mutant, JFP41, led to the genome-wide transcriptional analysis of cells induced to competence via addition of competence-stimulating peptide (CSP). A total of 128 genes were induced at least 2-fold, 74 of which were classified as either “early” or “late” based on their induction patterns. Expression patterns were verified using qRT-PCR. This study …

Development Of Thai Speech Audiometry Materials For Measuring Speech Recognition Thresholds, Lauren Alexandra Hart

Theses and Dissertations

Speech audiometry materials are essential for thorough audiological testing. One aspect of speech audiometry is evaluating an individual's speech recognition threshold (SRT). Recorded materials for SRT are available in many languages; however there are no widely published recorded SRT materials available in the Thai language. The goal of this study was to develop relatively psychometrically equivalent SRT materials for evaluating the hearing abilities of native speakers of the Thai language. To accomplish this, 90 commonly used bisyllabic Thai words were digitally recorded by a male and a female talker and evaluated by 20 native Thai listeners. Twenty-eight words with relatively …

Recognition Of Emotion In Facial Expressions By Children With Language Impairment, Dorthy A. Stott

Theses and Dissertations

Recent research has shown that children with language impairment (LI) have increased social difficulties. This study examined the relationship between language skills and emotion understanding through recognition of facial expressions of emotion in children with LI and their typically developing peers. It is a replication of the research of Spackman, Fujiki, Brinton, Nelson, and Allen (2005) and Atwood (2006). Participants consisted of 22 children with LI and 22 age- and gender-matched peers with typically developing language, from the age range of 7:0 to 10:11 years. They were shown photographs of faces conveying one of the following emotions: happiness, sadness …

The Effect Of A Pseudopalate On Voiceless Obstruent Production: A Spectral Evaluation Of Adaptation, Karie Lindsay Dean

Theses and Dissertations

Many studies in speech communication have provided valuable findings concerning the kinematic nature of speech articulation. This type of research often involves introducing an oral device to the vocal tract such as lingual pellets, magnets, and different forms of pseudopalates to track the movement and placement of the articulators. This study examined the effect of an electropalatography (EPG) pseudopalate on the production of five voiceless obstruents (/p, t, k, s/ and /sh/). Acoustic recordings from 20 adult speakers with typical speech production were made during three different speaking conditions: prior to pseudopalate placement, immediately after placement, and following 20 minutes …

Recognizing The Need To Dissemble Emotions In Hypothetical Social Scenarios: Differences In Children With Language Impairment, Emily Rowberry Jones

Theses and Dissertations

This study investigated the ability of children with LI to recognize the need to dissemble emotions. Participants included 22 children with LI and 22 typically developing peers, ages 7;1 to 11;0 years. Children were presented with 10 hypothetical social scenarios in which the main character experienced an emotion which should be dissembled for social purposes. The participant's responses were categorized as dissemblance or display. Children with LI reported that they would hide the experienced emotion significantly less often than their typical peers. Children in both groups reported higher levels of dissemblance when asked what their parents would want them to …

Promotion Of Tumor Cell Death Through The Induction Of, Tuyen Nguyen

Theses and Dissertations

Microtubule poisons have proven to be effective in the treatment of a variety of malignancies. Although taxol-based derivatives promote microtubule stabilization, there is continuing interest in compounds that, like colchicines, act as microtubule destabilizing agents. Previous work from this laboratory showed that the novel microtubule poison, JG- 03-14, was active against breast tumor cells, promoting autophagic cell death. In the current work, we studied the influence of JG-03-14 on p53 wild type HCT116 colon carcinoma cells. A crystal violet sensitivity assay indicated that JG-03-14 induced growth inhibition, with 75% suppression of growth evident at a concentration of 500 nM. Time …

Performance On Natural Dissemblance Tasks In 7-11 Year-Old, Language-Impaired And Typically Developing Children, Noel Quist

Theses and Dissertations

Studies over the past several years have shown that children with language impairment (LI) have greater difficulty in social situations than typically developing children. More specifically, studies have shown that children with LI have more difficulty with dissemblance. This study was conducted to assess whether these children are less likely to dissemble in real-life situations. Forty-four children aged 7 to 11 years (22 LI and 22 typically developing) were presented with four situations designed to elicit dissemblance. Their reactions were scored and compared. The results of this study showed subtle differences between children with LI and typically developing children. Children …

Development Of Tongan Materials For Determining Speech Recognition Thresholds, Lisa Dawn Bunker

Theses and Dissertations

Speech recognition threshold (SRT) is an important clinical measure that validates the pure-tone average (PTA), assists in diagnosis and prognosis of hearing and hearing impairment, and helps identify non-organic hearing impairment. Few published, recorded, and standardized materials exist in languages other than English, which results in audiologists testing individuals using materials developed in a non-native language. Research shows that this is problematic, as certain criterion for SRT testing are not met. Thus, performance may reflect test-language deficiency rather than hearing impairment. Currently, there are no known published materials for use in measuring the SRT in individuals whose native language is …

The Effects Of Task Preference On Speech And Motor Performance Under Divided Attention Conditions, Amy Sue Leiter

Theses and Dissertations

Dual task performance and the interaction of tasks has been the subject of much research. When tasks are performed together they affect each other to varying degrees depending upon such factors as the similarity of the tasks, their difficulty, and whether one task is given preference over another. In this study, task preference was investigated under divided attention conditions in order to determine what effect preference had on task performance. Twenty young adults took part in this study and were randomly assigned into two groups. Each group was experimentally motivated to favor one of the two tasks – either speaking …

Oral Retelling As A Measure Of Reading Comprehension: The Generalizability Of Ratings Of Elementary School Students Reading Expository Texts, Rachel Clinger Burton

Theses and Dissertations

The purpose of this study was to refine a rating procedure used to assess intermediate elementary school students' ability to orally retell what they had read from two expository passages. Oral retellings from 28 fourth grade students were tape-recorded and rated on two different occasions by each of 4 raters. A four-facet (passage, day of test administration, rater, and rating occasion) generalizability study was conducted using a partially nested design. The six largest sources of variability identified in the G-study included (a) students, (b) the student-by-day interaction, (c) the interaction of passage with rater (nested within student and day), (d) …

The Development Of Word Recognition Materials For Native Speakers Of Tongan, Lara Cahoon Seaver

Theses and Dissertations

The purpose of this study was to develop, digitally record, evaluate, and psychometrically equate a set of Tongan bisyllabic word lists for use in measurement of word recognition testing. Commonly used bisyllabic words were digitally recorded by male and female native talkers of Tongan. The psychometric performance of the words was measured at ten intensity levels (- 5 to 40 dB HL) in 5 dB increments by 20 listeners with normal hearing acuity. The 200 words with the highest rate of listener identification were included in four relatively psychometrically equivalent word lists of 50 words each and eight half-lists of …

The Experience Of Volunteering For Hurricane Katrina Relief / Theoretical Explanations For Nurses’ Involvement As Volunteers In Global Disasters, Deborah Ulmer

Theses and Dissertations

This study is about the nature of nurses' decision making related to volunteering to provide humanitarian aid in a major national disaster. Additionally, it is about the lived experience of nurses who volunteered in that disaster. It is a transcendental phenomenological study using the approach of Clarke Moustakas and the purpose of the study was to describe the experiences of the nurses, their reasons for volunteering, and the impact of their experience on their lives several years later.

Effects Of Altered Superoxide Dismutase Expression On Age-Related Functional Declines And Survival In Drosophila, Ian Martin

Theses and Dissertations

Most organisms experience progressive declines in physiological function as they age. A number of studies in a variety of species support a strong link between oxidative damage, age-related functional declines and life span determination. Here, manipulating the expression levels of superoxide dismutase (SOD) isoenzymes SOD1 and SOD2, resulted in altered functional senescence and survival characteristics in Drosophila. Overexpression of cytosolic Sod1 using the yeast GAL4/UAS system conferred a 30-34% increase in mean life span and resulted in an attenuated senescence of odor avoidance behavior in aging flies. Tissue-specific Sod1 overexpression selectively in the nervous system or muscle failed to reproduce …

Electrical Behavior Of Non-Aqueous Formulations: Role Of Electrostatic Interactions In Pressurized Metered Dose Inhalers (Pmdis), Reshma Kotian

Theses and Dissertations

Aerosol electrostatics is an important property of pharmaceutical aerosols. The electrostatic properties of pMDI aerosols have been shown to be a function of both formulation and packaging components. The modified ELPI enables measurement of aerosol charge as a function of particle size, and the simultaneous determination of the mass distribution using chemical analysis. However, in order to fully assess the cause and effects of aerosol electrostatics in terms of its biological and regulatory implications, it is necessary to understand the basic charging mechanisms inside the pMDI formulation.

Electrical resistivity and zeta potential measurements confirmed the presence of charged species within …

Inflammatory Regulation Of Cysteine Cathepsins, Blaine Creasy

Theses and Dissertations

Cysteine cathepsins B, L and S are endosomal/lysosomal proteases that participate in numerous physiological systems. Cathepsin expression and activity are altered during various inflammatory diseases, including rheumatoid arthritis, atherosclerosis, neurodegenerative diseases and cancers. Early immune responses to microbial pathogens are mediated by pattern-recognition receptors, including Toll-like receptors (TLR). Signaling through TLR causes cell activation and release of inflammatory mediators, which can contribute to the severity of chronic inflammatory diseases. The impact of TLR cell activation on cathepsins B, L and S activities was investigated using live-cell enzymatic assays. Individual ligands of TLR4, TLR2 and TLR3 increased intracellular activities of the …

Contamination Of Dental Waterlines: Efficacy Of Seven Waterline Treatments And Three In-Office Bacteria Test Kits, Adam Davis

Theses and Dissertations

This study compared seven dental unit water line (DUWL) treatments and three in-office bacteria test kits. Sodium hypochlorite (NaOCl) 1:10 in tap water weekly; 3 drops of NaOCl in 1 liter of water; Dentapure® DP 40; ICX™ tablet; Sterilex® Ultra powder; Lines™; and Selective Micro® Dental-Clean. Traditional culture technique was compared to HPC Dental Sampler; Aquasafe™ Dental Unit Water Line Test Kit; and Bacteria in Water Test Kit. Eight dental units in the Virginia Commonwealth University Graduate Endodontic Clinic were randomly assigned treatment regimens. Samples were taken weekly initially and after flushing for 1 minute. In conclusion NaOCl hypochlorite 1:10 …

Designing Non-Saccharide Heparin/Heparan Sulfate Mimics, Arjun Raghuraman

Theses and Dissertations

Glycosaminoglycans (GAGs) are complex biopolymers that play important roles in inflammation, coagulation, angiogenesis, cell adhesion and viral invasion by interacting with several different proteins.1,2 Structurally, GAGs are built up of several different sulfated disaccharide units.3 Specific GAG sequences that uniquely recognize their cognate proteins exist. Such specificity typically arises from the binding of unique sulfation patterns on the linear GAG chain to highly electropositive protein domains. Thus, these highly charged, sulfated biopolymers potentially represent a new class of therapeutics. Yet, the major stumbling block to the development to these agents is their extremely complicated and tedious chemical synthesis. We hypothesized …