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Falls are a leading cause of fatal and nonfatal injuries in the construction trades. This study explored construction workers’ self-reports of postural stability upon standing after working in different postures. One hundred and eighty-nine workers in 10 construction trades provided stability ratings by completing a written questionnaire. Additional data collected included age, gender, years of experience, and rating of overall balance. Construction workers rated their overall balance as high, furthermore, no difference was found between trades or age groups. Significant differences in stability ratings were provided for the various postures. The most commonly used non-erect postures (bent over at waist, squatting, and forward kneeling) resulted in the largest self-reports of instability. Sitting on elevated surface and sitting on level surface resulted in the highest levels of self-reported stability and are recommended when maintaining balance is a concern. Differences associated with construction trade and age were also found, but were thought to be attributed to differences in tasks performed since no differences were found when each posture was analyzed separately. The results suggest that the working posture used to complete a task affects the postural stability upon standing regardless of construction trade and age of worker. Findings may lead to recommendations for redesign of tasks or tools to reduce the use of certain working postures, particularly in high-risk environments such as construction.  相似文献   
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Two organic compounds, diethylstilboestrol a synthetic oestrogen substitute, and cyproheptadine which acts as an appetite stimulant in some mammals, were added separately at 3 different concentrations to diets fed to plaice (Pleuronectes platessa), and their effect on growth examined. Over a 10 week period, low orally-administered diethylstilboestrol (600 g/kg moist diet) gave rise to increased weight gain, food consumption and food conversion. Higher dietary concentrations of diethylstilboestrol (up to 2400 g/kg diet) were without effect on these parameters. Cyproheptadine did not stimulate appetite, weight gain or food conversion at any of the levels tested.With an Appendix on Statistics by J. A. Pope and A. M. Shanks  相似文献   
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A laboratory simulation of a reduction in water table height that could be anticipated from current climate change models, resulted in a change in the efficiency with which a valley-bottom wetland acted as a sink/source of nutrients. Effects were confined to the upper 10 cm of the profile, but since this depth has the greatest hydraulic conductivity, it was noted that the effects of hydrochemical changes therein would be readily transferred to receiving waterbodies. Marked changes in leachate chemistry were observed, including increases in nitrate and sulphate concentrations, while concentrations of phenolics, dissolved organic carbon, potassium, iron and ammonium decreased. These changes have implications for the quality and productivity of waters draining wetlands.  相似文献   
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