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Healthcare Acquired Infection Risk And Toothbrush Contamination In The Icu., Michelle Frazelle Dec 2011

Healthcare Acquired Infection Risk And Toothbrush Contamination In The Icu., Michelle Frazelle

Theses and Dissertations

Healthcare acquired infections (HAIs) are a complex and multi-factorial problem associated with high morbidity, mortality, and cost. Toothbrushes (TBs) may be at risk for contamination with potential pathogenic microorganisms (PPMs) from the patient care environment or autoinnoculation from the patient. We focused on three PPMs: multiply resistant Staphylococcus aureus (MRSA), vancomycin resistant Enterococcus (VRE), and Acinetobacter. Specific aims were to (1) describe environmental factors associated with TB contamination in the ICU; (2) describe the relationship between TB contamination and oral colonization in critically ill adults.


Characterization Of The Effect Of Serum And Chelating Agents On Staphylococcus Aureus Biofilm Formation; Chelating Agents Augment Biofilm Formation Through Clumping Factor B, Nabil Mathew Abraham Nov 2011

Characterization Of The Effect Of Serum And Chelating Agents On Staphylococcus Aureus Biofilm Formation; Chelating Agents Augment Biofilm Formation Through Clumping Factor B, Nabil Mathew Abraham

Theses and Dissertations

Staphylococcus aureus is the causative agent of a diverse array of acute and chronic infections, and some these infections, including infective endocarditis, joint infections, and medical device-associated bloodstream infections, depend upon its capacity to form tenacious biofilms on surfaces. Inserted medical devices such as intravenous catheters, pacemakers, and artificial heart valves save lives, but unfortunately, they can also serve as a substrate on which S. aureus can form a biofilm, attributing S. aureus as a leading cause of medical device-related infections. The major aim of this work was take compounds to which S. aureus would be exposed during infection and …


Childhood Maltreatment, Coping, And Coping Self-Efficacy Among Offenders, David Guion Nov 2011

Childhood Maltreatment, Coping, And Coping Self-Efficacy Among Offenders, David Guion

Theses and Dissertations

This study explored the relationship between childhood interpersonal trauma and coping self-efficacy, coping styles, and emotion regulation difficulties among male and female offenders in detention and diversion centers (N = 183). The coping-relapse model of recidivism posits that offenders’ coping ability plays a pivotal role in successful reentry (Zamble & Quinsey, 1997). Past research reveals that childhood maltreatment is associated with avoidant coping and emotion regulation difficulties, which could negatively impact reentry (e.g., Cloitre et al., 2009; Min, Farkas, Minnes, & Singer, 2007). The relationship between childhood maltreatment and coping self-efficacy has not been addressed. This study found that childhood …


Characterization Of Cyclic-Di-Gmp Signaling With The Lyme Spirochete, Borrelia Burgdorferi, Jessica Kostick Sep 2011

Characterization Of Cyclic-Di-Gmp Signaling With The Lyme Spirochete, Borrelia Burgdorferi, Jessica Kostick

Theses and Dissertations

Lyme disease is a tick-borne infection caused by Borrelia burgdorferi, B. garinii, and B. afzelii. These spirochetes experience environmental fluctuations as they are passed between mammalian and Ixodes tick hosts throughout their enzootic cycle. Recent studies have suggested cyclic diguanylate (c-di-GMP), a ubiquitous secondary messenger, is a key modulator of B. burgdorferi adaptive responses and may play a significant role in cycle progression. In this study, we examined the impact of the sole diguanylate cyclase (Rrp1), c-di-GMP binding proteins (PlzA and PlzB), and HD-GYP-containing phosphodiesterase (PdeB) in disease establishment of both murine and Ixodes tick systems. Strains harboring targeted gene …


The Use Of Targeted Charge-Reversal Nanoparticles (Tcrns) To Investigate Nuclear Delivery Of Fluorescent Agents To Cancer Cells: Implications For Novel Prostate And Breast Cancer Therapy, Mario Dance Sep 2011

The Use Of Targeted Charge-Reversal Nanoparticles (Tcrns) To Investigate Nuclear Delivery Of Fluorescent Agents To Cancer Cells: Implications For Novel Prostate And Breast Cancer Therapy, Mario Dance

Theses and Dissertations

Nanotechnology has recently emerged as a strong contributor toward research efforts to develop targeted systems of drug delivery in cancer therapy. Our work investigates the therapeutic potential of Targeted Charge-Reversal Nanoparticles (TCRNs), a novel nanoparticle with in vitro evidence of nuclear drug delivery. Using M12 prostate cancer cells, MDA-MB-231 breast cancer cells, and modified derivatives of these cell lines, we investigated the ability of Folic Acid-tagged TCRNs to deliver Nile Red and Dimethyl Indole Redfluorescent (DiR) fluorescent dyes to the nucleus of cells using confocal microscopy and in vivo biphontonic imaging using Xenogen® Technology. Confocal imaging with the SCP28 derivative …


The Regulation Of Tonb-Dependent Transporters In Neisseria Gnorrhoeae, Aimee Hollander Sep 2011

The Regulation Of Tonb-Dependent Transporters In Neisseria Gnorrhoeae, Aimee Hollander

Theses and Dissertations

Neisseria gonorrhoeae is an obligate human pathogen that causes the common sexually- transmitted infection, gonorrhea. Gonococcal infections cause significant morbidity, particularly among women, as the organism ascends to the upper reproductive tract, resulting in pelvic inflammatory disease, ectopic pregnancy and infertility. Antibiotic resistance rates have risen dramatically, leading to severe restriction of treatment options for gonococcal disease. Gonococcal infections do not elicit protective immunity nor is there an effective vaccine to prevent the disease. Thus, further characterization of expression, function and regulation of surface antigens could lead to better treatment and prevention modalities in the future. N. gonorrhoeae express a …


Gene Expression In The Right Ventricle During Development Of Pulmonary Hypertension, Jennifer Drake Sep 2011

Gene Expression In The Right Ventricle During Development Of Pulmonary Hypertension, Jennifer Drake

Theses and Dissertations

Pulmonary arterial hypertension (PAH) is a disease of the lung vessels that causes severe effects on the right ventricle of the heart; ultimately, most patients with severe PAH die as a result of right heart failure. However, little is known about the causes of right heart failure. Here, we describe a pattern of gene expression that differs between the normal rat left ventricle (LV) and right ventricle (RV). These genes are known to be involved in the development of the heart as well as adaptations to the heart during stress. This gene expression pattern is used as a baseline to …


The Abundance And Infection Status Of Anopheles Spp. Mosquitoes At Three Sites In Loudoun County, Northern Virginia, Priya Krishnan Aug 2011

The Abundance And Infection Status Of Anopheles Spp. Mosquitoes At Three Sites In Loudoun County, Northern Virginia, Priya Krishnan

Theses and Dissertations

Malaria is a re-emerging infectious disease with approximately half of the world's population at risk. In the US, since the 1950’s the Center for Disease Control (CDC) has been reporting between 1,000 and 1,500 cases of malaria every year. A majority of these cases were among US travellers and were attributed to Plasmodium falciparum. In August 2002, two cases of human malaria due to Plasmodium vivax were reported in Loudoun County, Northern Virginia. The Center for Disease Control and Prevention concluded that these cases were acquired locally. This was because of an absence of other risk factors such as international …


Characterizing The Distribution Of Planktonic Fecal Bacteria In The James River, Richmond, Virginia, John Furry Aug 2011

Characterizing The Distribution Of Planktonic Fecal Bacteria In The James River, Richmond, Virginia, John Furry

Theses and Dissertations

Surface waters containing fecal bacteria present significant public health risks. Understanding the sources of and factors affecting the distribution of fecal-indicating bacteria is necessary to predict potential illnesses more effectively. This thesis presents two studies on the distribution of fecal bacteria in the James River through Richmond, Virginia. Chapter 1 describes nearly 11 years of water quality, climate, and hydrologic data that occurred with changes in Escherichia coli concentrations, concluding that Richmond contributes significant quantities of fecal bacteria to the James River, and that the distribution of these bacteria varies seasonally. Chapter 2 details the development of Polymerase Chain Reaction …


Development Of Computational Tools And Resources For Systems Biology Of Bacterial Pathogens, Ranjit Kumar Aug 2011

Development Of Computational Tools And Resources For Systems Biology Of Bacterial Pathogens, Ranjit Kumar

Theses and Dissertations

Bacterial pathogens are a major cause of diseases in human, agricultural plants and farm animals. Even after decades of research they remain a challenge to health care as they are known to rapidly evolve and develop resistance to the existing drugs. Systems biology is an emerging area of research where all of the components of the system, their interactions, and the dynamics can be studied in a comprehensive, quantitative, and integrative fashion to generate predictive models. When applied to bacterial pathogenesis, systems biology approaches will help identify potential novel molecular targets for drug discovery. A pre-requisite for conducting systems analysis …


Distribution Of Field Caught Mosquitoes From Laredo, Texas, Yvette Patricia Mendoza Aug 2011

Distribution Of Field Caught Mosquitoes From Laredo, Texas, Yvette Patricia Mendoza

Theses and Dissertations

Within the last decades, mosquito-borne viruses have re-emerged in the United States. These infectious viruses include Dengue, West Nile, St. Louis Encephalitis, and Chikungunya, just to name a few. Originating in sub-tropical and tropical regions, these viruses and the mosquitoes that transmit them know no borders. Laredo, Texas is a town which borders Nuevo Laredo, Tamaulipas, Mexico; an area that is known to have frequent outbreaks of the Dengue virus. Identifying the diversity of mosquito species and the abundance of mosquitoes in the City of Laredo is a key element in aiding local public health officials in disease surveillance. This …


The Characterization Of Avian Polyomavirus, Satellite Tobacco Mosaic Virus, And Bacteriophage Cw02 By Means Of Cryogenic Electron Microscopy, Peter S. Shen Aug 2011

The Characterization Of Avian Polyomavirus, Satellite Tobacco Mosaic Virus, And Bacteriophage Cw02 By Means Of Cryogenic Electron Microscopy, Peter S. Shen

Theses and Dissertations

Viruses are the most abundant biological entity in the biosphere and are known to infect hosts from all domains of life. The aim of my work is to identify conserved and non-conserved features among the capsid structures of related and divergent icosahedral viruses via cryogenic electron microscopy, sequence analysis, molecular modeling, and other techniques. Bird polyomaviruses often cause severe disease in their hosts whereas mammalian polyomaviruses generally do not. Avian polyomavirus is a type of bird polyomavirus with an unusually broad host range compared to the restricted tropism of other polyomaviruses. Although most polyomaviruses have a conserved, rigid capsid protein …


Development And Evaluation Of A Multiplex Suspension Array Protocol For The Detection Of Enteric Pathogens From Clinical Specimens, Carol Walters Jul 2011

Development And Evaluation Of A Multiplex Suspension Array Protocol For The Detection Of Enteric Pathogens From Clinical Specimens, Carol Walters

Theses and Dissertations

Foodborne illnesses are a significant public health challenge in the United States, with an estimated 9.4 million illnesses annually attributed to the consumption of contaminated food, of which 59% are estimated to be caused by viruses, 39% by bacteria and 2% by parasites. Timely detection and identification of the pathogens causing foodborne outbreaks is vital for the implementation of outbreak control strategies, allowing public health officials to prevent additional illnesses and maintain confidence in the food supply. Public health laboratories employ a variety of traditional and molecular testing techniques to identify foodborne outbreak etiologic agents. One technology is the Luminex …


An Invasive Species Reduces Aquatic Insect Flux To Terrestrial Food Webs, Steven S. Merkley Jul 2011

An Invasive Species Reduces Aquatic Insect Flux To Terrestrial Food Webs, Steven S. Merkley

Theses and Dissertations

Although it is well documented how introduced species can negatively affect native species, we only poorly understand how they may alter ecosystem functions. We investigated how an invasive fish affected the flux of aquatic insects to terrestrial food webs using mesocosms in a desert spring ecosystem. We compared aquatic insect emergence between alternative community states with monocultures and polycultures of two native species of fish, least chub (Iotichthys phlegethontis) and Utah chub (Gila atraria) plus, introduced western mosquitofish (Gambusia affinis). We tested three hypotheses: (1) aquatic insect biomass will be greater than terrestrial insect …


Changes In Life History Within An Individual's Lifetime, Eric J. Billman Jul 2011

Changes In Life History Within An Individual's Lifetime, Eric J. Billman

Theses and Dissertations

A central goal of life history theory is to understand the selective factors that generate the diversity of reproductive patterns observed in nature. Within lifetime changes in reproductive investment will determine an organism's fitness; however, this area of life history theory has received less attention than comparisons among population that characterize life history traits as a single population mean. Reproductive allocation can be affected by multiple cues; the integration of these cues across an organism's lifetime generates the diversity in life history strategies observed in nature. Life history studies should examine the interacting effects of multiple cues on life history …


Structures Of Poliovirus And Antibody Complexes Reveal Movements Of The Capsid Protein Vp1 During Cell Entry, Jun Lin Jul 2011

Structures Of Poliovirus And Antibody Complexes Reveal Movements Of The Capsid Protein Vp1 During Cell Entry, Jun Lin

Theses and Dissertations

In the infection process, native poliovirus (160S) first converts to a cell-entry intermediate (135S) particle, which causes the externalization of capsid proteins VP4 and the N-terminus of VP1 (residues 1-53). The externalization of these entities is followed by release of the RNA genome, leaving an empty (80S) particle. Three antibodies were utilized to track the location of VP1 residues in different states of poliovirus by cryogenic electron microscopy (cryo-EM). "P1" antibody binds to N-terminal residues 24-40 of VP1. Three-dimensional reconstruction of 135S-P1 showed that P1 binds to a prominent capsid peak known as the "propeller tip". In contrast, our initial …


Adaptive Threat Detector Testing Using Bayesian Gaussian Process Models, Bradley Thomas Ferguson May 2011

Adaptive Threat Detector Testing Using Bayesian Gaussian Process Models, Bradley Thomas Ferguson

Theses and Dissertations

Detection of biological and chemical threats is an important consideration in the modern national defense policy. Much of the testing and evaluation of threat detection technologies is performed without appropriate uncertainty quantification. This paper proposes an approach to analyzing the effect of threat concentration on the probability of detecting chemical and biological threats. The approach uses a probit semi-parametric formulation between threat concentration level and the probability of instrument detection. It also utilizes a bayesian adaptive design to determine at which threat concentrations the tests should be performed. The approach offers unique advantages, namely, the flexibility to model non-monotone curves …


Cumulative Risks To Eastern Oysters, Crassostrea Virginica In The James River, Va, Vrushali Lele May 2011

Cumulative Risks To Eastern Oysters, Crassostrea Virginica In The James River, Va, Vrushali Lele

Theses and Dissertations

In an effort to apply Cumulative Risk Assessment (CRA) as developed by the U.S. EPA, the present study investigates the cumulative risks to Eastern oysters due to multiple stressors such as salinity, temperature and oxygen and carbon dioxide. I also compared the effectiveness of the Hazard Quotient Method (HQ) in CRA. Ambient conditions in the James River, VA were obtained from the Virginia DEQ database and respiratory responses were estimated using values from the literature. The multiple environmental stresses are evaluated using a probabilistic analysis that combines the environmental conditions. It was concluded that salinity was the most influential stressor …


Preventing The Spread Of Infections In Patients' Homes: What Is The Best Evidence?, Julie Ferry May 2011

Preventing The Spread Of Infections In Patients' Homes: What Is The Best Evidence?, Julie Ferry

Theses and Dissertations

Nurses need evidence-based practices to prevent the spread of infections in patients' homes. Nursing equipment must be cleaned and disinfected properly between patients and proper hand hygiene should be done to decrease health-care associated infections in the home and community setting. A review and synthesis of the most current literature was done by searching the Cumulative Index to Nursing and Allied Health literature (CINAHL), Cochrane Database, Google Scholar™ and Google™ databases. Key words include infection control, home visits, public health, cleaning, home health, equipment, disinfectants and combinations of those words. Tools were created for dissemination to nurses providing care in …


Genetic Variation And Leprosy Distribution In Nine-Banded Armadillos, Leah Chinchilla Apr 2011

Genetic Variation And Leprosy Distribution In Nine-Banded Armadillos, Leah Chinchilla

Theses and Dissertations

Genetic, ecological, and environmental variation within and among populations of hosts and pathogens can influence local susceptibility of hosts and transmission rates of pathogens. These complex interactions can lead to geographic variation in the prevalence of pathogens. The interaction between leprosy and nine-banded armadillos in the southeastern U.S. provides an opportunity to examine the genetic, ecological, and environmental factors contributing to the variation in pathogen prevalence on a large geographic scale. Using genotypic data for loci associated with the immune response to leprosy and for anonymous loci, we have assessed the population structure of armadillo populations across the southern U.S. …


A Proteomic Approach To Profiling The Pipping Muscle Of The Broiler Embryo, Adebayo Oluwaseun Sokale Apr 2011

A Proteomic Approach To Profiling The Pipping Muscle Of The Broiler Embryo, Adebayo Oluwaseun Sokale

Theses and Dissertations

The Musculus complexus (pipping muscle) plays a primary role in the hatching of the chick from the eggshell at the end of its embryonic life. Various metabolic and cellular changes have been associated with the pipping muscle during development. These studies profiled the pipping muscle at the molecular level by identifying proteins which are associated with the developmental changes. In the first phase of the study, protein expression profile of the Day 13 chicken embryo pipping muscle was obtained using DDF with nano HPLC mass spectrometric analyzer. Identified proteins were categorized based on Gene Ontology. In the second phase, pipping …


Accelerating Finite State Projection Through General Purpose Graphics Processing, Thomas Trimeloni Apr 2011

Accelerating Finite State Projection Through General Purpose Graphics Processing, Thomas Trimeloni

Theses and Dissertations

The finite state projection algorithm provides modelers a new way of directly solving the chemical master equation. The algorithm utilizes the matrix exponential function, and so the algorithm’s performance suffers when it is applied to large problems. Other work has been done to reduce the size of the exponentiation through mathematical simplifications, but efficiently exponentiating a large matrix has not been explored. This work explores implementing the finite state projection algorithm on several different high-performance computing platforms as a means of efficiently calculating the matrix exponential function for large systems. This work finds that general purpose graphics processing can accelerate …


Combating Biological Terrorism From Imported Food, Jeffrey S. Nelson Mar 2011

Combating Biological Terrorism From Imported Food, Jeffrey S. Nelson

Theses and Dissertations

There is a threat that a terrorist or terrorist organization will use access to the US food supply to kill or sicken Americans by contaminating imported food products from Mexico. The food that Americans eat is coming more and more often from foreign countries such as Mexico. Foodborne diseases infect nearly fifty million people in the US each year, resulting in over three thousand deaths. There are many terrorist organizations that would like to deliberately contaminate American food. Drug cartels and terrorist organizations currently operate in Mexico, one of the leading food importers into the US. The purpose of this …


Development Of Prototype Gold Nanoparticle-Dased Immunoassays For The Detection Of Plasmodium Falciparum Hsp70, Bassem Samy Guirgis Feb 2011

Development Of Prototype Gold Nanoparticle-Dased Immunoassays For The Detection Of Plasmodium Falciparum Hsp70, Bassem Samy Guirgis

Theses and Dissertations

Biomedical nanotechnology is providing revolutionary opportunities for the rapid and simple diagnosis of many infectious diseases. About half of the world's population are at risk of infection with malaria and diagnostic assays available either lack sensitivity and specificity or require expensive equipment, expertise or costly infrastructure; that are not usually available in countries where the disease is endemic. Thus, there is an urgent need to develop rapid, sensitive, and inexpensive diagnostic tests for malaria for both high- and low-resource settings. In this study, we developed two prototype gold nanoparticle (AuNP)-based immunoassays for the detection of Plasmodium falciparum Heat Shock Protein …


Using Culture Independent Approaches To Gain Insights Into Human Urinary Tract Microbiome In Healthy Male And Female Individuals, Sarah Hussein El-Alawi Feb 2011

Using Culture Independent Approaches To Gain Insights Into Human Urinary Tract Microbiome In Healthy Male And Female Individuals, Sarah Hussein El-Alawi

Theses and Dissertations

Here we present comprehensive insights into the diverse collection of bacterial communities that indigenously inhabit the urinary tract of healthy adult male and female individuals using cultivation independent techniques. Several studies address the importance of uncultured microbial flora that inhabits the human urinary tract in health and diseases. Thus, a deep and accurate understanding of the factors influencing this ecological niche and its microbiome is important to prevent possible infectious diseases. Genomic DNA was extracted from midstream urine samples collected from 4 adult, healthy and culture-negative male and female individuals at ages ranging from 18 to 40. Following PCR amplifications …


The Characterization Of Pg0228 In Porphyromonas Gingivalis W83, Courtney Schlenker Jan 2011

The Characterization Of Pg0228 In Porphyromonas Gingivalis W83, Courtney Schlenker

Theses and Dissertations

Periodontitis affects 10 to 15 percent of most adult populations and can contribute to numerous systemic diseases. Porphyromonas gingivalis, a gram-negative anaerobic bacterium, is a recognized prime causative agent in periodontitis. Studies have shown a number of small non-coding RNAs (sRNAs) have been related to bacterial virulence. Many of these sRNAs require the facilitation of the bacterial Sm-like protein, Hfq, for optimum function. Hfq is a RNA chaperone involved in RNA stability, sRNA function, and polyadenylation. Mutants lacking in Hfq often show pleiotropic phenotypes, although the extent and severity of hfq null phenotypes is often species-specific. Hfq has been encoded …


Acquired Cytogenetic Changes In Adult Twins Discordant For A History Of Childhood Sexual Abuse, Jenni Brumelle Jan 2011

Acquired Cytogenetic Changes In Adult Twins Discordant For A History Of Childhood Sexual Abuse, Jenni Brumelle

Theses and Dissertations

The primary study aim was to evaluate the latent biological effect of childhood sexual abuse (CSA) on adults by quantifying acquired cytogenetic changes and cortisol levels in identical twins who were discordant (N=22) or concordant (N=2) for a history of CSA. Although the difference scores for cortisol values between discordant identical co-twins were not significantly different from zero, a trend was observed for the twins exposed to intercourse, the most severe form of CSA, to have a blunted cortisol awakening response. Acquired cytogenetic changes were assessed by scoring telomere lengths and somatic cell abnormality frequencies via a cytokinesis-block micronucleus (MN) …


Synthesis, Screening And Cocrystallization Of Adenosine Based Inhibitors With Methyltransferases, Ermc' And Ksga, Matthew Baker Jan 2011

Synthesis, Screening And Cocrystallization Of Adenosine Based Inhibitors With Methyltransferases, Ermc' And Ksga, Matthew Baker

Theses and Dissertations

Antibiotic resistance threatens to throw mankind back into an era when infectious disease was the predominant cause of death. In an effort to mitigate this danger, we targeted ErmC’ and KsgA. Both methylate N6-adenosine of ribosomal RNA, though each serve different roles in their bacterial host. ErmC’ dimethylates A2058 on 23S rRNA, conferring resistance to MLSB antibiotics (macrolides, lincosamides, streptogramin B). KsgA aids in ribosome assembly, binding inactive 30S until dimethylating A1518/A1519 of 16S rRNA. Like most methyltransferases, ErmC’ and KsgA use cofactor S-adenosylmethionine (SAM) as their methyl source, which binds adjacent to their specific adenosine substrate. ErmC’ inhibitors could …


Landscape Ecology Of Amphibians And Their Parasites In The Sheyenne National Grasslands, Kyle D. Gustafson Jan 2011

Landscape Ecology Of Amphibians And Their Parasites In The Sheyenne National Grasslands, Kyle D. Gustafson

Theses and Dissertations

No abstract provided.


Current Development Of The Ndx-1 Prototype : Critical Analysis Of The Actual Status, Lynn Van Broock Jan 2011

Current Development Of The Ndx-1 Prototype : Critical Analysis Of The Actual Status, Lynn Van Broock

Theses and Dissertations

No abstract provided.