ABSTRACT INTRODUCTION: Multi-drug resistant tuberculosis (MDR-TB) poses a great threat to the eradication of TB. In the US, MDR-TB is faced with inadequate diagnostic tools and long and expensive treatment regimens. Therefore, preventing the disease is the key to saving lives and resources. Social and behavioral variables play a big part in this prevention. It is important to determine the social factors that may lead to MDR-TB in order to set up prevention programs and more efficient treatment regimens. AIM: This study was conducted to ascertain the social determinants of MDR-TB in the US between the years of 2005 and 2009 to better equip public health officials to deal with this growing threat. METHODS: This study used the Centers for Disease Control and Prevention (CDC) Online Tuberculosis Information System (OTIS) database to find associations between certain social variables and MDR-TB. The variables that were tested were whether or not the individual had lived in a correctional facility for the past year; HIV status; homelessness; whether or not the individual had an occupation; and whether the individual was foreign-born or US-born. An unadjusted odds ratio (OR) was calculated to find this association. The variables were then stratified with age; sex; race; age and race; age and sex; and age, sex, and race to see whether or not the strata were confounders. RESULTS: The variables of having lived in a correctional facility and homelessness were found to be associated with MDR-TB. However, all of the strata were found to be confounders for this relationship. Having HIV and being US-born were not found to be associated with MDR-TB. All of the strata for HIV were found to be confounders. But for place of birth, stratifying by age, sex, and both age and sex were not confounders. The rest of the strata were. The OR for occupation versus MDR-TB was almost at 1, meaning that those with a job and those without a job had almost equal odds of having MDR-TB. Effect modification was present for the strata in all variables, meaning that the risk of having MDR-TB varied with each different age, sex, and racial group. DISCUSSION: Results from this study showed which variables were more likely to be associated with MDR-TB in the US between the years of 2005 and 2009. However, when compared to the literature that exists, the results showed that more research needs to be done to properly ascertain this relationship. Using this study, public health officials can identify which populations to focus prevention efforts on.

Corrosion of reinforced concrete is the most challenging durability problem that threatens reinforced concrete structures, especially structures that are subject to severe environmental conditions (i.e., Highway Bridges, Marine structures, etc.). Corrosion of reinforcing steel leads to cracking and spalling of the concrete cover and billions of dollars are spent every year on repairing such damaged structures. New types of reinforcements have been developed in order to avoid these high cost repairs. Thus it is important to study the corrosion behavior of these new types of reinforcements and compare them to the traditional carbon steel reinforcements.<p> This study aimed at characterizing the corrosion behavior of three competing reinforcing steels; conventional carbon steel, micro-composite steel (MMFX-2) and 316LN stainless steel, through experiments in carbonated and non-carbonated concrete exposed to chloride-laden environments. Synthetic pore water solutions have been used to simulate both cases of sound and carbonated concrete under chloride ions attack. A three electrode corrosion cell is used for determining the corrosion characteristics and rates. Multiple electrochemical techniques were applied using a Gamry PC4 potentiostat manufactured by GAMRY INSTRUMENTS. DC corrosion measurements were applied on samples subjected to fixed chloride concentration in the solution. EIS measurements were applied on samples subjected to incremental chloride additions. Furthermore, carbon steel rebars embedded in concrete samples pre-contaminated with chloride ions added to the mix will be used to relate corrosion rates inside concrete to those obtained from synthetic solutions and to measure moisture content inside concrete using a nondestructive TDR-based technique.

Enterococci bacteria that cannot be treated eectively with the antibiotic vancomycin are termed Vancomycin-Resistant Enterococci (VRE). In this thesis, we develop a mathematical framework for determining optimal strategies for prevention and treatment of VRE in an Intensive Care Unit (ICU). A system of ve ordinary dierential equations describes the movement of ICU patients in and out of dierent states related to VRE infection. Two control variables representing the prevention and treatment of VRE are incorporated into the system. An optimal control problem is formulated to minimize the VRE-related deaths and costs associated with controls over a nite time period. Pontryagin's Minimum Principle is used to characterize optimal controls by deriving a Hamiltonian expression and dierential equations for ve adjoint variables. Numerical solutions to the optimal control problem illustrate how hospital policy makers can use our mathematical framework to investigate optimal cost-eective prevention and treatment schedules during a VRE outbreak. / McAnulty College and Graduate School of Liberal Arts; / Computational Mathematics / MS; / Thesis;

Corrosion of reinforced concrete is the most challenging durability problem that threatens reinforced concrete structures, especially structures that are subject to severe environmental conditions (i.e., Highway Bridges, Marine structures, etc.). Corrosion of reinforcing steel leads to cracking and spalling of the concrete cover and billions of dollars are spent every year on repairing such damaged structures. New types of reinforcements have been developed in order to avoid these high cost repairs. Thus it is important to study the corrosion behavior of these new types of reinforcements and compare them to the traditional carbon steel reinforcements.<p> This study aimed at characterizing the corrosion behavior of three competing reinforcing steels; conventional carbon steel, micro-composite steel (MMFX-2) and 316LN stainless steel, through experiments in carbonated and non-carbonated concrete exposed to chloride-laden environments. Synthetic pore water solutions have been used to simulate both cases of sound and carbonated concrete under chloride ions attack. A three electrode corrosion cell is used for determining the corrosion characteristics and rates. Multiple electrochemical techniques were applied using a Gamry PC4 potentiostat manufactured by GAMRY INSTRUMENTS. DC corrosion measurements were applied on samples subjected to fixed chloride concentration in the solution. EIS measurements were applied on samples subjected to incremental chloride additions. Furthermore, carbon steel rebars embedded in concrete samples pre-contaminated with chloride ions added to the mix will be used to relate corrosion rates inside concrete to those obtained from synthetic solutions and to measure moisture content inside concrete using a nondestructive TDR-based technique.

No description available.

Thesis (Ph. D.)--OGI School of Science and Engineering at OHSU, 2001.

The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on January 22, 2010). Thesis advisor: Dr. Reid J. Smeda. Includes bibliographical references.

Thesis (M.S.C.E.)--University of Massachusetts Amherst, 2009. / Open access. Includes bibliographical references (p. 87-89).

Thesis (Ph. D.)--West Virginia University, 2002. / Title from document title page. Document formatted into pages; contains xvi, 140 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 137-140).

Thesis (Ph. D.)--Lehigh University, 2003. / Includes vita. In two parts. Includes bibliographical references (leaves 602-609).