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In its search for an objective overall diagnostic evaluation, the University of Illinois Library of the Health Sciences' Program Evaluation Committee selected a book availability measure; it is easy to administer and repeat, results are reproducible, and comparable data exist for other academic and health sciences libraries. The study followed the standard methodology in the literature with minor modifications. Patrons searching for particular books were asked to record item(s) needed and the outcome of the search. Library staff members then determined the reasons for failures in obtaining desired items. The results of the study are five performance scores. The first four represent the percentage probability of a library's operating with ideal effectiveness; the last provides an overall performance score. The scores of the Library of the Health Sciences demonstrated no unusual availability problems. The study was easy to implement and provided meaningful, quantitative, and objective data. 相似文献
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The length-tension relationship of muscle contraction is well documented in adults. However, research on this relationship in children has been limited. The aim of this study was to compare differences in the torque-joint angle relationship of the quadriceps muscle in children and adults. Eight boys aged 8-10 years and eight men aged 20-26 years performed two maximal voluntary isometric contractions at six knee joint angles (20 degrees, 40 degrees, 60 degrees, 80 degrees, 90 degrees, 100 degrees). The mean of the two trials was used as the performance measure. Both groups demonstrated an expected increase in relative torque as the joint angle increased (P< 0.05). The men produced significantly greater relative torque at 20 degrees, 40 degrees and 60 degrees knee flexion (P < 0.05). The percentage of maximal torque at these angles for the men and boys respectively were: 35.2+/-4.3 vs 15.2+/-12%, 63.6+/-9.1 vs 51.8+/-16.8% and 93.6+/-6.5 vs 84.4+/-14.4%. There were no group differences at 80 degrees or 90 degrees. Peak torque was attained at 80 degrees in men, but decreased significantly (P< 0.05) at 90 degrees and 100 degrees. For boys, peak torque was attained at joint angles of 80 degrees and 90 degrees. The reduction in peak torque at 100 degrees was not statistically significant, but the relative torque at this angle was lower in men than in boys (77.9+/-13.7 vs 87.1+/-10.4%; P< 0.05). In conclusion, the relationship between torque and joint angle appears to be affected by age. 相似文献