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921.
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924.
Stewart P Rice C Beatty P Wilson B Stewart W Blair A 《Applied occupational and environmental hygiene》2002,17(6):444-453
Questionnaires are increasingly being used in the workplace to assess exposures to chemicals and other agents. Although the literature contains much information on questionnaire design in general, little information is available on the challenges related to questionnaires applied to the occupational setting. Questionnaires on dry cleaning workers, nurses, farmers, car mechanics, and truck drivers were administered to a total of 25 people currently performing one of these jobs. After asking each question, the interviewer probed to identify the difficulties the respondents had in answering the questions. Overall, the respondents were able to answer the questions. Problems were found, however, with particular questions that reduced the effectiveness of the questionnaire. These included the use of unclear terms, questions open to multiple interpretations, difficult computational requirements (e.g., asking for averages for highly variable tasks), ineffective transitions between topics, and overlapping response categories. This type of testing is a crucial part of questionnaire development and can be used to effectively identify potential problems with questions and, therefore, improve them to enhance collection of higher-quality data for assessments of occupational exposures. 相似文献
925.
Pate RR Freedson PS Sallis JF Taylor WC Sirard J Trost SG Dowda M 《Annals of epidemiology》2002,12(5):303-308
PURPOSE: To use objective monitoring of physical activity to determine the percentages of children and youth in a population that met physical activity guidelines. METHODS: A total of 375 students in grades 1-12 wore an accelerometer (CSA 7164) for seven consecutive days. Bouts of continuous activity and accumulation of minutes spent in physical activity at various intensities were calculated to determine how many students met three physical activity guidelines. RESULTS: Over 90% of students met Healthy People 2010, Objective 22.6 and nearly 70% met the United Kingdom Expert Consensus Group guideline, both of which recommend daily accumulation of moderate physical activity. Less than 3% met Healthy People 2010, Objective 22.7, which calls for bouts of continuous vigorous physical activity. For the United Kingdom Expert Consensus Group guideline, compliance decreased markedly with age, but gender differences were not statistically significant. CONCLUSIONS: Prevalence estimates for compliance with national physical activity guidelines varied markedly for the three guidelines examined. Objective monitoring of physical activity in youth appears to be feasible and may provide more accurate prevalence rates than self-report measures. 相似文献
926.
PURPOSE: Reproductive factors are often evaluated in epidemiologic interview studies as risk factors for diseases in women. Similarly, childhood social class has been implicated in the etiology of several diseases. Nevertheless, questions related to these factors have not been thoroughly evaluated for test-retest reliability. This research measured the test-retest reliability of reproductive and childhood social class variables, and determined whether reliability differed by case-control status, age, educational level, time between interviews, and interviewer-rated quality of the interview. METHODS: Subjects were participants in a population-based case-control in-person interview study of Hodgkin's disease in northern California women. Twenty-four cases and 22 controls were reinterviewed by telephone between 1992 and 1995, with an average interval of 8 months between interviews. Reliability was assessed using kappa or intraclass correlation coefficients; mean reliability coefficients and 95% confidence intervals (CIs) were estimated using the bootstrap method. RESULTS: Reliability was excellent for all variables (reliability coefficients between 0.76 and 0.96) and did not differ by case-control status (mean reliability = 0.82 for cases and 0.84 for controls), age (mean reliability = 0.85 for age < 40 and 0.82 for age > or = 40), time between interviews (mean reliability = 0.75 for 0-5 months, 0.88 for 6-11 months, and 0.87 for 1 year or more), or interviewer-rated quality of the validity of the original responses (mean reliability = 0.93 for "not too confident" and 0.83 for "confident"). However, reliability was consistently lower among less educated women (mean reliability = 0.56 for high school or less and 0.88 for more than high school), a finding consistent with results of prior studies. CONCLUSIONS: These results indicate that questions about reproductive experience and childhood social class posed in in-person interviews can be answered reliably. However, inclusion of subjects at lower socioeconomic status may result in lower reliability for some interview responses. 相似文献
927.
There are arguments for and against organic agriculture. The paper looks at the impact of changes and development, the need for sustainable development, organic farming as a viable alternative, organic certification and concluding thoughts on why organic farming makes sense. To go organic does not necessarily mean that organic products are totally free of chemical pesticides but they have a lower pesticide residue. Organic certification, a process guarantee not a product guarantee, becomes necessary if a farmer has to sell organic food products locally (to tourists) or export overseas. For Pacific organic producers, the biggest obstacle lies with certification costs and initial investments in research and extension to educate consumers and farmers about organic agriculture organic methods. 相似文献
928.
Miller WH Seefeld MA Newlander KA Uzinskas IN Burgess WJ Heerding DA Yuan CC Head MS Payne DJ Rittenhouse SF Moore TD Pearson SC Berry V DeWolf WE Keller PM Polizzi BJ Qiu X Janson CA Huffman WF 《Journal of medicinal chemistry》2002,45(15):3246-3256
Bacterial enoyl-ACP reductase (FabI) catalyzes the final step in each cycle of bacterial fatty acid biosynthesis and is an attractive target for the development of new antibacterial agents. Our efforts to identify potent, selective FabI inhibitors began with screening of the GlaxoSmithKline proprietary compound collection, which identified several small-molecule inhibitors of Staphylococcus aureus FabI. Through a combination of iterative medicinal chemistry and X-ray crystal structure based design, one of these leads was developed into the novel aminopyridine derivative 9, a low micromolar inhibitor of FabI from S. aureus (IC(50) = 2.4 microM) and Haemophilus influenzae (IC(50) = 4.2 microM). Compound 9 has good in vitro antibacterial activity against several organisms, including S. aureus (MIC = 0.5 microg/mL), and is effective in vivo in a S. aureus groin abscess infection model in rats. Through FabI overexpressor and macromolecular synthesis studies, the mode of action of 9 has been confirmed to be inhibition of fatty acid biosynthesis via inhibition of FabI. Taken together, these results support FabI as a valid antibacterial target and demonstrate the potential of small-molecule FabI inhibitors for the treatment of bacterial infections. 相似文献
929.
Stewart MJ Steenkamp V van der Merwe S Zuckerman M Crowther NJ 《Human & experimental toxicology》2002,21(12):643-647
The traditional Zulu remedy impila (Callilepis laureola) can cause acute fatal hepatocellular necrosis, especially in children. We investigated the mechanism(s) of toxicity using HuH-7 hepatocytes. Impila tubers were extracted with boiling water and the aqueous extract was used at different concentrations to study the effects on the morphology of the cells. Flow cytometry and labelling with fluorescent antibodies to tubulin were also used. At high concentrations, necrosis occurred; however, at lower concentrations, the extracts gave rise to a variety of changes including hypercondensation of chromatin, multinucleate cells, nuclear fragmentation and apoptosis. In addition, we observed destruction of cytoplasmic tubulin. These findings give further insight into the mechanism of toxicity of herbal remedies containing atractyloside. 相似文献
930.
Stewart J 《Experimental and clinical psychopharmacology》2002,10(2):96-8; discussion 101-3
Contexts and expectations can change the subjective and physiological effects of psychotropic drugs. Learning and conditioning processes clearly contribute to some of these effects. It must be considered, however, that even the acute effects of drugs can be significantly altered by the context in which they are administered. The challenge is to determine the mechanisms operating to bring about these changes. 相似文献