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排序方式: 共有1014条查询结果,搜索用时 15 毫秒
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Awkward wrist posture is generally considered an occupational risk factor for hand/wrist disorders, leading to the ergonomic design principle of "bend the tool, not the wrist." Sixteen participants performed a computer jumper installation task and a simple assembly task while productivity, wrist posture, and shoulder posture were measured. The work surface orientation (vertical and 45 degrees) and the level of constraint placed on the user (constrained grip and unconstrained grip) were also varied. The results indicate that the beneficial effects of the bent-handle pliers are task dependent. In the computer jumper task the bent-handle pliers resulted in 5.3% faster task performance, whereas in the assembly task performance was 4.9% faster with the straight-handle pliers. The bent-handle pliers reduced shoulder deviations by 50% in the jumper installation task, and ulnar deviation was reduced by 12% and 22% for the jumper installation task and the assembly task, respectively (all significant at p < .05). However, allowing participants to hold the pliers in a grip configuration of their choosing (unconstrained technique) often reduced these postural benefits. In applying these results to workplace design activities, one should recognize that the ergonomic utility of bent-handle pliers can be considerable but that the 3-D kinematics characteristics of the task must be considered. 相似文献
64.
Compared the effects of signaled and unsignaled shock on the pituitary-adrenal response of 68 male Long-Evans hooded rats. In Exp I, exposure to the 2 procedures yielded no difference in plasma corticosterone levels. In Exp II, the addition of a food-reinforced leverpressing baseline produced conditioned suppression in the signaled condition but no group difference in steroid values. To guard against steroid elevations produced by exposure to shock, blood samples in Exp III were obtained during brief test sessions prior to the occurrence of shock. The procedure resulted in a significant elevation in the steroid levels of the signaled shock group. In Exp IV, a within-Ss sampling procedure revealed that disparate group steroid values obtained earlier in the session had converged by the end of the test session. The final experiment produced the original failure to obtain a steroid difference due to predictability in the absence of a behavioral baseline. Results suggest that (a) the effects of predictability are largely seen in the temporal pattern of steroid elevations and not in their terminal values, (b) the effects of predictability on steroids are modulated by the availability of control, and (c) control is not confined to the stimulus that is being predicted. (36 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
65.
The use of multiple freeze (-20 degrees C)-thaw cycles in combination with isoeugenol and polysorbate 80 was investigated as a method for the reduction of numbers of Listeria monocytogenes cells in a bacteriological medium. Three freeze (1 h, -20 degrees C)-thaw cycles in the presence of isoeugenol at concentrations of 0, 100, and 300 ppm resulted in average L. monocytogenes reductions of 0.69, 2.65, and 3.3 log10 MPN (most probable number) per ml, respectively. Increasing the number of freeze-thaw cycles further decreased cell numbers, with reductions of nearly 5 log10 MPN/ml being obtained with six freeze-thaw cycles. Freeze-thaw cycles were effective in reducing cell numbers at isoeugenol concentrations down to 25 ppm. Rapid freezing rates with liquid nitrogen were found to be less effective in reducing numbers of L. monocytogenes cells. Two rapid freeze-thaw cycles in the presence of 100 ppm isoeugenol and polysorbate 80 resulted in a reduction of 1.45 log10 MPN/ml. Two freezing (-20 degrees C) cycles involving slow freezing and thawing rates with samples being held frozen for 6 h for each cycle resulted in reductions larger than those obtained with faster freezing rates. It was found that complete thawing in freeze-thaw cycles was not necessary to achieve bactericidal action. The application of multiple freeze-thaw cycles in combination with low concentrations of isoeugenol could effectively reduce numbers of L. monocytogenes cells in bacteriological media. 相似文献
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Bradley Katharine A.; Bush Kristen R.; Davis Tania M.; Dobie Dorcas J.; Burman Marcia L.; Rutter Carolyn M.; Kivlahan Daniel R. 《Canadian Metallurgical Quarterly》2001,15(4):297
This study evaluated the prevalence and associated risks of binge drinking, defined as having ≥4 drinks on an occasion in the past year, in a female patient population. Of 1,259 female Veterans Affairs patients surveyed, 780 reported drinking alcohol in the past year, and 305 (24% of respondents, 39% of drinkers) reported binge drinking in the past year; 84 (11% of drinkers) had done so monthly or more often. Age-adjusted logistic regression analyses indicated that women who reported past-year binge drinking monthly or more often reported significantly increased odds of morning drinking (odds ratio [OR]?=?40.3), others worrying about their drinking (OR?=?38.6), arguments after drinking (OR?=?13.5), hepatitis or cirrhosis (OR?=?3. 1), frequent injuries (OR?=?2.6), smoking (OR?=?3.7), drug use (OR?=?22.2), and multiple sexual partners (OR?=?4.6). (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
68.
Chapman Michael; Zahn-Waxler Carolyn; Cooperman Geri; Iannotti Ronald 《Canadian Metallurgical Quarterly》1987,23(1):140
To investigate affective and dispositional factors in the motivation of children's helping, 60 children ranging from preschool to sixth grade were observed in laboratory distress incidents involving, as potential recipients of aid, a kitten, an adult experimenter, and a mother with an infant. Positive, negative, and neutral affect expressions were observed in two of the three distress incidents, and prosocial dispositions were assessed through children's attributions regarding the motives and feelings of characters in eight stories involving persons in distress. Results indicated that helping tended to be positively correlated with positive affect and negatively correlated with negative and neutral affect. Further evidence suggested that these correlations were primarily attributable to positive affects associated with helping itself rather than to affects experienced in witnessing the other's distress. Among story attributions, attributions of guilt were strongly and consistently related to helping and affect expression in the total sample and across grade groupings. Attributions of empathy and altruism were also related to helping, but only in the total sample. These results are interpreted as suggesting that it may not be empathic arousal alone that is most important for the motivation of helping, but the subjective meaning of that arousal in terms of an accompanying sense of responsibility for the other person's plight. (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
69.
Carolyn Stone 《Urban Policy and Research》2013,31(4):147-155
Abstract This paper considers the development of community transport in Sydney and possible directions for its furture. It outlines the basis on which the community transport movement has developed and argues that the conditions which have given rise to a community transport movement are likely to be exacerbated in the future. 相似文献
70.
Minds and Machines - 相似文献