The effect of inflammation on Shiga toxin absorption in vivo

Hemolytic Uremic Syndrome (HUS), the leading cause of acute renal failure in children in the United States, is a systemic complication of Enterohemorrhagic Escherichia coli (EHEC) infection that is caused by the systemic effects of Shiga toxins (Stx) produced by EHEC. Every year approximately 70,000 people in the United States are infected with EHEC, and up to 10% go on to develop HUS. Although it is known that Stx causes HUS, the mechanism of Stx translocation from the intestinal lumen to the systemic circulation is poorly understood. In vitro studies have shown that migration of neutrophils across polarized mucosal epithelial cells enhances the translocation of Stx, but it is not known if a similar phenomenon occurs in vivo. This dissertation tests the hypothesis that the host inflammatory response allows or enhances the translocation of Stx from the intestinal lumen to the systemic circulation. To test the hypothesis, we developed a 3-day-old pig model of EHEC infection using E. coli O157:H7. Colostrum fed neonatal pigs infected with E. coli O15T:H7 at 3 days of age, were colonized by E. coli O157:H7 and developed typical attaching and effacing (A/E) lesions, but lacked a histologically detectable inflammatory response and systemic signs and lesions of Stx toxicosis. In the second set of experiments, we induced inflammation in the cecum, spiral colon, and rectum of neonatal pigs using dextran sulfate sodium (DSS). In the final set of experiments, we compared clinical signs and systemic lesions of Stx toxicosis in pigs infected with E. coli O157:H7 with and without a large intestinal inflammatory response, and in pigs orally dosed with crude Stx preparation with and without a large intestinal inflammatory response. We found that severe suppurative and ulcerative inflammation in the large intestine does not enhance Stx translocation from the intestinal lumen to the systemic circulation in vivo. Further work needs to be done to determine the effect of less severe inflammatory changes on Stx translocation

A Study of Asynchronous Learning Options that Promote Continuity of Learning in K-12 Settings

A capstone submitted in partial fulfillment of the requirements for the degree of Doctor of Education in the College of Education at Morehead State University by Timothy Wade Bobrowski on April 11, 2013

Perceptions of Educational Equality in Tennessee: A Comparison of City School Systems vs. County School Systems in Northeast Tennessee.

The majority of city and county school systems throughout Tennessee and the United States at one time or another experience a budget crisis. In the state of Tennessee, school systems are funded through the Basic Education Program, established in 1992 as part of the Tennessee Education Improvement Act. The lawsuit of 1988, Tennessee Small School Systems v. McWherter, created the Basic Education Program. Through the years, the Basic Education Program has provided extra teaching positions, materials, and supplies and has provided the funding formula for school systems throughout the state. Many high-ranking administrators contend that the Basic Education Program has outlasted its time. School administrators from both city and county school systems indicate the program needs to be restructured to meet the current needs of the schools and students throughout the state of Tennessee. The purpose of this mixed-method study was to explore the perceptions of educational equality and the advantages/disadvantages of the Basic Education Program. Through quantitative data, city and county school systems were compared for per-pupil spending, average teacher salary, and student achievement in the advanced proficient category for math and reading/language. These data were collected from the Tennessee Department of Education website and the Tennessee Education Association website. Qualitative data were collected through interviews with high-ranking administrators from city and county school systems in Northeast Tennessee. These administrators were purposively selected from systems containing both city and county schools. The findings of this study demonstrated that city school systems have higher per-pupil spending and higher teacher salaries than county systems. City school systems have higher student achievement levels in the advanced proficient category than county school systems. Interview participants agree that educational equity does not exist between city and county school systems in the state of Tennessee. The participants in this study express that although the Basic Education Program in Tennessee was effective, at one time, it should be restructured or redefined to meet the current needs of all students in the state of Tennessee

Race, Nativism, and the Making of Class in Antebellum City-Mysteries

This study analyzes white working-class identity construction in antebellum popular print culture and offers a fresh perspective on race relations in the antebellum period. By analyzing anti-slavery and nativist political discourses in popular fiction and newspapers of the 1840's and 1850's, I argue that sensational novels by such writers as George Lippard, Augustine Duganne, and Ned Buntline provided space whereby working-class whites could articulate their anxieties toward wage labor and critique the professional classes through a sympathetic identification with free, northern African Americans. My first chapter reveals how city-mysteries, largely bereft of heroic, white working-class agents of change, rely upon dynamic black male protagonists and the racially ambivalent discourse of "wage slavery" to appeal to the multi-racial working classes. In this context, I discuss Lippard's The Quaker City; or, the Monks of Monk-Hall and New York: Its Upper Ten and Lower Million, in which Lippard mounts class critique through representations of the "Herculean" black male hero that resonate with contemporary depictions of the white laborer and through class-inflected minstrelsy discourse. My second chapter examines the role of anti-Catholic and anti-immigrant nativist discourse in city-mysteries' economic critique of chattel slavery. When Lippard, Duganne, and to a lesser extent, Buntline, present their white working-class characters as the victims of literal and figurative enslavement plots by Catholic officials and dissipated, slave-owning merchants, nativism proves a flexible rhetoric that reinforces the texts' racial sympathy and helps to develop class protest against the professional classes. My third and final chapter illuminates the cross-racial strategies of class protest among early labor newspapers, early African-American newspapers, weekly story papers, and nativist newspapers--an array of under-studied print sources that register the potential and the limits of cross-racial solidarity during the antebellum period

Subtribal Relationships in Tribe Tradescantieae (Commelinaceae)Based on Molecular and Morphological Data

Tribe Tradescantieae (Commelinaceae) consists of seven subtribes and 25 genera. Previous attempts to evaluate phylogenetic relationships within the group using morphology or the chloroplast-encoded rbcL have either been highly homoplasious (morphology) or provided only weak support for subtribal relationships due to insufficient variability (rbcL). In this study, phylogenetic analysis of nucleotide sequence data from the chloroplast-encoded ndhF and rbcL genes, as well as 47 morphological and anatomical characters, were used to evaluate relationships within and among the subtribes of Tradescantieae. The addition of ndhF resulted in a more highly resolved phylogeny and greater bootstrap and decay values than were obtained by rbcL alone or rbcL and morphology. The analyses suggest the following: (1) subtribes Coleotrypinae, Cyanotinae, and Tradescantiinae (with the addition of Elasis) are monophyletic; (2) subtribe Thyrsantheminae is polyphyletic; and (3) subtribe Dichorisandrinae is polyphyletic. Members of Dichorisandrinae are united into two clades (Dichorisandra and Siderasis; Cochliostema, Geogenanthus, and Plowmanianthus) whose relationships are more clearly resolved. The position of Old World subtribes Cyanotinae and Coleotrypinae, nested within New World taxa suggested by rbcL studies, are supported by the addition of ndhF data

LOWER BODY PEAK FORCE BUT NOT POWER IS AN IMPORTANT DISCRIMINATOR OF ELITE SENIOR RUGBY LEAGUE PLAYERS

This investigation determined differences in lower body strength and power between elite junior (17-20 years) and elite senior (open-aged) rugby league athletes. Twenty junior and 25 senior athletes performed an isometric mid-thigh pull, countermovement jump, repeated jump, and broad jump tests during a National Rugby League pre-season. The effects of age (junior vs. senior) and position (adjustables vs. hit-up forwards vs. outside backs) on test results were investigated using a two-way analysis of variance. Cohen’s d effect sizes (ES) and 95% confidence intervals were calculated for pairwise comparisons. Isometric mid-thigh pull absolute peak force was greater for senior players compared to junior players (ES=0.88, p<.05). Countermovement jump absolute peak power was greater for outside backs (ES=1.12) and hit-up forwards (ES=1.23) compared to adjustables (p<.05), greater for senior outside backs compared to junior outside backs (ES=1.53, p<.05), and greater for junior hit-up forwards compared to senior hit-up forwards (ES=1.00, p<.05). This research demonstrated the differences in strength and power of rugby league athletes between playing age and position. Improving lower body strength should be prioritised for athletic development of junior rugby league athletes, with consideration given to requirements across different playing positions

Equivalency of risk for a modified health endpoint: a case from recreational water epidemiology studies

BACKGROUND: The United States Environmental Protection Agency (USEPA) and its predecessors have conducted three distinct series of epidemiological studies beginning in 1948 on the relationship between bathing water quality and swimmers’ illnesses. Keeping pace with advances in microbial technologies, these studies differed in their respective microbial indicators of water quality. Another difference, however, has been their specific health endpoints. The latest round of studies, the National Epidemiological Assessment of Recreational (NEEAR) Water studies initiated in 2002, used a case definition, termed “NEEAR GI illness” (NGI), for gastrointestinal illness corresponding closely to classifications employed by contemporary researchers, and to that proposed by the World Health Organization. NGI differed from the previous definition of “highly credible gastrointestinal illness” (HCGI) upon which the USEPA’s 1986 bathing water criteria had been based, primarily by excluding fever as a prerequisite. METHODS: Incidence of NGI from the NEEAR studies was compared to that of HCGI from earlier studies. Markov chain Monte Carlo method was used to estimate the respective beta binomial probability densities for NGI and HCGI establish credible intervals for the risk ratio of NGI to HCGI. RESULTS: The ratio of NGI risk to that of HCGI is estimated to be 4.5 with a credible interval 3.2 to 7.7. CONCLUSIONS: A risk level of 8 HCGI illnesses per 1000 swimmers, as in the 1986 freshwater criteria, would correspond to 36 NGI illnesses per 1000 swimmers. Given a microbial DNA-based (qPCR) water quality vs. risk relationship developed from the NEEAR studies, 36 NGI per 1000 corresponds to a geometric mean of 475 qPCR cell-equivalents per 100 ml

Incidence and public health burden of sunburn among beachgoers in the United States.

The beach environment creates many barriers to effective sun protection, putting beachgoers at risk for sunburn, a well-established risk factor for skin cancer. Our objective was to estimate incidence of sunburn among beachgoers and evaluate the relationship between sunburn incidence and sun-protective behaviors. A secondary analysis, of prospective cohorts at 12 locations within the U.S. from 2003 to 2009 (n&nbsp;=&nbsp;75,614), were pooled to evaluate sunburn incidence 10-12&nbsp;days after the beach visit. Behavioral and environmental conditions were cross-tabulated with sunburn incidence. Multivariable logistic regression was used to estimate the association between new sunburn and sun-protective behaviors. Overall, 13.1% of beachgoers reported sunburn. Those aged 13-18&nbsp;years (16.5%), whites (16.0%), and those at beach locations along the Eastern Seaboard (16.1%), had the highest incidence of sunburn. For those spending ≥5&nbsp;h in the sun, the use of multiple types of sun protection reduced odds of sunburn by 55% relative to those who used no sun protection (Odds Ratio&nbsp;=&nbsp;0.45 (95% Confidence Interval:0.27-0.77)) after adjusting for skin type, age, and race. Acute health effects of sunburn tend to be mild and self-limiting, but potential long-term health consequences are more serious and costly. Efforts to encourage and support proper sun-protective behaviors, and increase access to shade, protective clothing, and sunscreen, can help prevent sunburn and reduce skin cancer risk among beachgoers