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11.
Lifting and carrying heavy loads occur frequently among ironworkers and result in high prevalence and incidence rates of low back complaints, injuries and work-disability. From a health perspective, little information is available on the effect of team lifting on work demands and workload. Therefore, the objective of this study was to compare the effects of team lifting of maximally 50 kg by two ironworkers (T50) with team lifting of maximally 100 kg by four ironworkers (T100). This study combined a field and laboratory study with the following outcome measures: duration and frequency of tasks and activities, energetic workload, perceived discomfort and maximal compression forces (Fc peak) on the low back. The physical work demands and workload of an individual iron worker during manual handling of rebar materials of 100 kg with four workers did not differ from the manual handling of rebar materials of 50 kg with two workers, with the exception of low back discomfort and Fc peak. The biomechanical workload of the low back exceeded for both T50 and T100 the NIOSH threshold limit of 3400N. Therefore, mechanical transport or other effective design solutions should be considered to reduce the biomechanical workload of the low back and the accompanying health risks among iron workers.  相似文献   
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Ironworkers frequently perform heavy lifting tasks in teams of two or four workers. Team lifting could potentially lead to a higher variation in peak lumbar compression forces than lifts performed by one worker, resulting in higher maximal peak lumbar compression forces. This study compared single-worker lifts (25-kg, iron bar) to two-worker lifts (50-kg, two iron bars) and to four-worker lifts (100-kg, iron lattice). Inverse dynamics was used to calculate peak lumbar compression forces. To assess the variability in peak lumbar loading, all three lifting tasks were performed six times. Results showed that the variability in peak lumbar loading was somewhat higher in the team lifts compared to the single-worker lifts. However, despite this increased variability, team lifts did not result in larger maximum peak lumbar compression forces. Therefore, it was concluded that, from a biomechanical point of view, team lifting does not result in an additional risk for low back complaints in ironworkers.  相似文献   
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M Frank  S Bell  R Nowik  M Faber 《Child welfare》1989,68(1):69-78
Day care in Israel is not always of high quality, and the current forecast for upgrading the standards of the existing centers is bleak, due to economic and social factors that do not place high priority on quality infant care in group settings. The agency attempted, therefore, to develop a low-cost, efficient method of early intervention, wherein skilled social workers were hired, given special training, and worked alongside the caregivers of day care centers to help children and parents defined as at risk. This article describes the observations that were made and the interventions that were chosen.  相似文献   
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This article investigates the issues of the stability and predictability and interest-sensitivity of money demand over 1870–1997. Two different estimation methodologies are used - random coefficient (RC) modeling and vector error correction (VEC) modeling. The former procedure allows the profiles of the coefficients to be traced over time and relaxes several restrictions routinely imposed in applied work. The results indicate that different estimation methodologies using different data periods and frequencies yield estimates of some of the coefficients of the long-run demand for money that fall within a fairly narrow range. The results also suggest that specification errors have had an important influence on the time profile of the interest elasticity of money demand and that there is a tendency for the interest elasticity to decline in absolute value as interest rates decline.  相似文献   
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Children in the western world often are socialized as meat-eaters, while caring much about animals. Yet we know little about how children think about eating animals and animal products, which will have important consequences for global meat consumption. Participants (n = 479, 80% White British, 57% female; children n = 119, Mage = 10.03, SD = 0.72; young adults n = 181, Mage = 19.09, SD = 0.85; adults n = 179, Mage = 40.97, SD = 8.18) reasoned about the acceptability of eating animals and animal products. Using the framework of social domain theory, we found that that children focused on moral concerns (p < .001, ηp2 = .01), whereas adults referenced conventions about the natural and necessary components of eating meat. Participants across age groups reported eating animal products (e.g., milk) to be acceptable because animals were not harmed. Together these results indicate that attempts to reduce meat consumption ought to be tailored in a domain-specific manner to age groups.  相似文献   
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