2 resultados para Related products

em DRUM (Digital Repository at the University of Maryland)


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The burden of chronic diseases such as cancer is increasing in low and middle income countries around the globe. Nepal, one of the world’s poorest countries, is no exception to this trend, with lung cancer as the leading causes of cancer deaths. Despite this, limited data is available on the environmental and behavioral risk factors that contribute to the lung cancer etiology in Nepal. The objectives of this dissertation are to: 1) investigate the ethnic differences in consumption of local tobacco products and their role in lung cancer risk in Nepal; 2) evaluate urinary metabolite of 1,3-butadiene as a biomarker of exposure to combustion related household air pollution (CRHAP); 3) investigate the association between CRHAP exposure and lung cancer risk using urinary metabolite of 1,3-butadiene as a biomarker of exposure; 4) investigate the association between CRHAP exposure and lung cancer risk using questionnaire based measure of exposure. Lung cancer cases (n=606) and frequency matched controls (N=606) were recruited from B.P. Koirala Memorial Cancer Hospital. We obtained biological samples and information on lifestyles including cooking habits and type of fuels used. We used liquid chromatograph tandem mass spectrometer (LC-MS/MS) to quantify urinary metabolites of 1,3-butadiene in urine samples. We employed a combination of logistic and linear regression models to detect any exposure-disease associations while controlling for known confounding variables. Overall, we found that ethnic groups in Nepal use different tobacco products that have different differing cancer potency -we observed the highest odds ratios for the traditional tobacco products. The biomarker analysis showed strong evidence that monohydroxybutyl mercapturic acid is associated with biomass fuel use among participants. However, we did not find significant association between urinary MHMBA and lung cancer risk. When we used questionnaire based measure of exposure to household air pollution, we observed significant, dose-response associations between CRHAP exposure and lung cancer risk, particularly among never-smokers. Our results show that important role of local tobacco products in lung cancer risk in Nepal. Furthermore, we demonstrate that CRHAP exposure is a risk factor for lung cancer risk, independent of tobacco smoking.

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This study explores how two American history teachers - one novice and one experienced – make in-the-moment choices among their history subject matter and classroom-related purposes during the teaching of an American history unit. Using classroom observations, lesson artifacts, student work products, and deep, retrospective interviews with the teachers as they watched videos of their teaching, this study maps out in detail the teachers’ purposes, both within and across different lesson activity structures. This study finds that the novice and the experienced teacher navigated among their purposes differently from each other, and that the characteristics of each teacher’s purposes navigation aligned with student outcomes in that teacher’s class. The novice teacher acted more like a juggler, with visible, reactive navigation among each purpose operational throughout his teaching; student outcomes in his class were similarly fragmented and discrete. The experienced teacher presented more like an orchestra conductor, interweaving his purposes and anticipating the navigation decisions that would create a more seamless whole; student outcomes in his class were aligned with his holistic navigation of purposes. Findings from this study have important implications for education research and teacher practice, including the relationship between teachers’ navigation among purposes and desired student outcomes, the integral role of classroom-related purposes interwoven with history subject matter purposes in teachers’ decision-making, and the differences in purposes navigation between a novice and an experienced history teacher.