Controlling the Public and Animal Health Threat from Campylobacter Infection in Broiler Chickens by Improving Gut Health and Reducing Inflammation

Campylobacter is a Gram-negative bacterium that causes disease in both humans and avian species. Poultry products present a major public health risk due to high levels of Campylobacter contamination which is a major cause of human bacterial gastroenteritis. Chickens are a primary reservoir for Campylobacter and there are no effective measures in place to inhibit flock colonisation and the extraintestinal spread of pathogenic strains. A large degree of variation is observed within the two Campylobacter species, C. jejuni and C. coli at both the genomic and phenotypic level. This has led to inconsistent findings when investigating the mechanisms by which Campylobacter spreads from the chicken gastrointestinal tract to edible tissues using in vitro and in vivo models. Feed additives are an increasingly popular alternative to antibiotic use in poultry farming; they present low risk of increasing antibiotic resistance and can be administered easily through food and/or water. The aim of this study was to determine the potential of three feed additives and four probiotic species as preventative measures for Campylobacter extraintestinal spread in poultry production. In chapter 3, a collection of Campylobacter isolates were sequenced and evaluated for their genotypic differences before being assessed in an avian and human cell line for their invasive capacity in vitro. Three isolates were selected based on their consistent in vitro invasive spectrum. In chapter 4, the selected Campylobacter isolates were challenged directly with feed additives to assess the impact on bacterial growth and motility. A significant reduction in Campylobacter growth was observed when challenged with 1.0% and 1.4% sodium butyrate over 24h. In chapter 5, human and avian cell lines treated with feed additives and exposed to Campylobacter isolates and focused on determining the cytotoxicity and any protective effects of the additives against transcellular invasion and cytokine production. Pre-treatment of epithelial cell monolayers did not significantly affect transcellular invasion of the bacterium. Chromium propionate significantly increased oxygen consumption in epithelial cells. Sodium butyrate at 0.6% increased epithelial cell production of inflammatory cytokines CXCLi1 and CXCLi2 . This thesis has; i) confirmed the diversity of Campylobacter species; ii) identified the direct inhibitory effects of feed additives on Campylobacter growth; iii) identified a novel mechanism of modified oxygen consumption by chromium propionate on epithelial cells; iv) identified the ability of sodium butyrate to induce CXCLi1/2 chemokines in avian epithelial cells. This work supports the growing evidence that feed additives are important alternatives for controlling Campylobacter in the chicken gut

Working with ArcGIS 9.2 manual

This manual is intended for undergraduate and graduate students learning to use ArcView 9 in a classroom setting. It is meant to be a complement, rather than substitute, for ArcView software manuals, ESRI training products, or the ArcView help options. It reflects the order and emphasis of topics that I have found most helpful while teaching introductory GIS classes. I expect that it will be particularly helpful to people new to GIS who may be intimidated by conventional software manuals. It may also be helpful as a resource to those who have completed a course in ArcView but don’t always remember how to perform particular tasks. This manual does not try to be comprehensive, focusing instead on the basic tools and functions that users new to GIS should know how to use. Those who master these basic functions should have the skills to learn about additional tools, using the ArcView help menus, or just exploring additional menu options, toolbars, and buttons

WEB Du Bois and the Negro Problem : Thoughts on Violence in Philadelphia

This sermon, delivered at First Unitarian Church of Philadelphia, might also be called Why a white girl from New Hampshire is studying The Philadelphia Negro. This essay/sermon connects Du Bois\u27s 1896 survey of Philadelphia to the violence currently plaguing Philadelphia

Who Received Loans? Home Owners\u27 Loan Corporation Lending and Discrimination in Philadelphia in the 1930\u27s

The lending record of the Home Owners’ Loan Corporation (HOLC) has received little attention compared with HOLC’s residential security maps. Specifically, the extent to which HOLC practiced racial and ethnic discrimination in the process of making and servicing more than a million loans to homeowners during the Depression has not been carefully examined. Using primary sources including HOLC publications, newspaper articles, 1930 census data, and mortgage records from Philadelphia, this research shows that HOLC did make loans to African Americans, Jews, and immigrants. Evidence suggests, however, that HOLC supported racial segregation in the process of reselling properties acquired through foreclosure

Why Social Work Needs Mapping

Relative to other fields, social work has been slow to adopt geographic information systems (GIS) as a tool for research and practice. This paper argues that GIS can benefit social work by: (1) continuing and strengthening the social survey tradition; (2) providing a framework for understanding human behavior; (3) identifying community needs and assets; (4) improving the delivery of social services; and (5) empowering communities and traditionally disenfranchised groups. Examples from a social work course on GIS and published social work research help illustrate these points. The paper concludes by considering the ways that social work can contribute to the development of GIS

Spatial Analysis of Historical Redlining: A Methodological Explanation

Despite widespread belief that redlining contributed to disinvestment in cities, there has been little empirical analysis of historical lending patterns. The lack of appropriate data and clear definitions of redlining has contributed to this void. This article reviews definitions and methods that have emerged from research on lending in recent years and considers how they can be applied to research on historical redlining. Address-level mortgage data from Philadelphia from the 1940s are analyzed using spatial regression, “hot spot” analysis, and surface interpolation. Employing multiple definitions of redlining that focus on process and outcome, as well as spatial and statistical relationships in lending, the analyses result in a series of map layers that indicate where redlining may have occurred. In addition to providing some evidence of lending discrimination, this article promotes an explicitly spatial view of redlining that has conceptual and methodological implications for research on contemporary and historical redlining

Redlining and the Homeowners\u27 Loan Corporation

This article analyzes the impact of the residential security maps created by the Home Owners’Loan Corporation (HOLC) during the 1930s on residential mortgages in Philadelphia. Researchers have consistently argued that HOLC caused redlining and disinvestment in U.S. cities by sharing its color-coded maps. Geographic information systems and spatial statistical models were used to analyze address-level mortgage data from Philadelphia to determine if areas with worse grades actually had less access to residential mortgage credit as a result. Findings indicate that the grades on HOLC’s map do not explain differences in lending patterns with the exception of interest rates, which were higher in areas colored red. Archival material and journal articles from the 1930s also reveal that lenders were avoiding areas colored red before HOLC made its maps, that HOLC’s maps were not widely distributed, and that lenders had other sources of information about real estate risk levels

Residential Security Maps and Neighborhood Appraisals. The Homeowners\u27 Loan Corporation and the Case of Philadelphia

At the request of the Home Loan Bank Board, the Home Owners’ Loan Corporation (HOLC) created color-coded maps for cities across the country between 1935 and 1940 that indicated risk levels for long-term real estate investment. Involvement in this City Survey Program marked a departure from the original mission of HOLC to provide new mortgages on an emergency basis to homeowners at risk of losing their homes during the Depression. This article considers why HOLC made these maps, how HOLC created them, and what the basis was for the grades on the maps. Geographic information systems and spatial regression models are used to show that racial composition was a significant predictor of map grades, controlling for housing characteristics

Community Activists and University Researchers Collaborating for Affordable Housing: Dual Perspectives on the Experience

This paper describes and analyzes the successful collaboration between the Philadelphia Affordable Housing Coalition and the Cartographic Modeling Laboratory at the University of Pennsylvania. This collaboration resulted in a research study that helped the Coalition secure an additional $10 million for affordable housing in Philadelphia. The perspectives of the activist and researcher on the collaboration are presented in their own voices and they describe their expectations, efforts to build relationships, define roles, and deal with different work styles and culture. Recommendations for building effective research partnerships are also provided

Closing the Gap: Housing (un)Affordability in Philadelphia

Low-income households struggle to afford housing in Philadelphia. Surveys, including the US Census and American Housing Survey, consistently confirm what housing advocates, public officials, and low-income residents already know: housing costs too much relative to what low-income households receive from lowwage jobs and public assistance. This study focuses on the poorest households in Philadelphia?those earning under $20,000. In 2000, Philadelphia had 206,251 households earning less than$20,000 a year?a full 35 percent of all households in the city