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It is well recognized that performance changes over time. However, the effect of these changes on overall assessments of performance is largely unknown. In a laboratory experiment, we examined the influence of salient Gestalt characteristics of a dynamic performance profile on supervisory ratings. We manipulated performance trend (flat, linear-improving, linear-deteriorating, U-shaped, and ∩-shaped), performance variation (small, large), and performance mean (negative, zero, positive) within subjects and display format (graphic, tabular) between subjects. Participants received and evaluated information about the weekly performance of different employees over a simulated 26-week period. Results showed strong main effects on performance ratings of both performance mean and performance trend, as well as interactions with display format. Theoretical and practical implications of the results are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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PM Gatongi ME Scott S Ranjan JM Gathuma WK Munyua H Cheruiyot RK Prichard 《Canadian Metallurgical Quarterly》1997,68(4):323-336
A study was undertaken in a semi-arid area of Kenya between August 1991 and June 1993 to evaluate the effects of anthelmintic treatment using ivermectin before or during the rains, on performance of mixed sheep and goat flocks, in comparison with an untreated flock. Performance parameters measured included age and weight of dams at first parturition, parturition intervals, body weights of dams and offspring, and birth weights, growth rates, and mortality rates of offspring. Among these parameters, birth weights and growth rates of offspring were found to be significantly improved by the treatment administered before the rains compared with the other two treatments. Mortality was lower in lambs and kids with high birth weights. Treatment, either before or during the rains, significantly reduced the faecal egg output and improved body weight, packed cell volume and flock fertility. Liveweight was confirmed to be a better measure of sexual maturity than age. It was further shown that lambs and kids, born of dams at their first lambing or kidding, experienced higher mortality rates than lambs and kids born of dams in their second and subsequent parturitions. Overall, treatment with ivermectin before the onset of rains was equal to or better, in terms of the performance parameters measured, than treatment during the rains, whilst treatment compared with no treatment increased performance in almost all of the parameters measured. 相似文献
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Using 376 airmen, Whitlock and Cureton (see 35: 7252) collected attitude score and biographical data, which is reanalysed in the present study, using multiple regression techniques. "… much of the criterion variance associated with attitude measures is also related to more easily obtained biographical characteristics of workers and biographical variables should be considered when relating attitudes to productivity." (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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葫芦峪金矿床位于华北克拉通南缘华熊地块崤山地体内,矿区出露地层为太古界太华群,未见中酸性岩体出露,金矿体主要受NW向断裂破碎带控制,以构造蚀变岩型为主,其次为石英脉型。成矿阶段可分为石英-黄铁矿阶段、石英-多金属硫化物阶段、石英-碳酸盐阶段。石英-多金属硫化物阶段是主要成矿阶段,该阶段形成的石英δD值介于-79‰~-98‰,δ18OH2O值变化范围为2.20‰~6.89‰,反映成矿流体主要为岩浆水,并有大气降水的加入。矿石中黄铁矿δ34S值介于3.8‰~5.0‰,均值为4.0‰;闪锌矿δ34S值介于4.0‰~5.0‰,均值为4.5‰。矿石中金属矿物206Pb/204Pb值为17.818 4~18.023 3,均值为17.933 3;207Pb/204Pb值为15.516 7~15.548 4,均值为15.536 2;208Pb/204Pb值为38.226 4~38.322 7,均值为38.289 8。硫铅同位素组成表明,成矿物质主要来自于隐伏的燕山期花岗岩。 相似文献
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JT Viitasalo 《Canadian Metallurgical Quarterly》1982,7(3):182-188
Fourteen Finnish and ten Russian elite male volleyball players were studied for their anthropometric dimensions, maximal isometric trunk extension and flexion, leg extension strength and vertical jumping height. In addition, the height of rise of the body centre of gravity h (C.G.), and the height of the hand and ball were analyzed from a video tape in spike and block jumps taken during actual competition. The two teams were found to differ significantly in the h (C.G.) during a vertical jumping test where a preliminary counter movement was allowed and in the lengths of lower limbs and legs; the Russian volleyball players jumped higher and had longer lower extremities. In actual competition, the hands of the Russian players while performing a spike were on the average ten centimeters higher (p less than .01) than the hand of the Finnish players. No significant differences were found, however, between the teams in the h (C.G.) during spiking. This finding seems to suggest that the Russians have better spike technique. 相似文献
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冀西石湖金矿床中黄铁矿的热爆特征及其启示 总被引:1,自引:0,他引:1
研究了不同世代黄铁矿的爆裂温度、爆裂曲线等成因矿物学信息及其与金矿化的关系。结果表明,黄铁矿的起爆温度可划分为4个区间,依次对应Ⅰ→Ⅱ→Ⅲ→Ⅳ4个成矿阶段;黄铁矿热爆裂曲线归纳为A、B、C3种基本类型,含金性好的黄铁矿的热爆曲线大多是B型曲线,含金性差或不合金的黄铁矿的热爆曲线大多属于A型曲线;曲线上有中低温峰的黄铁矿金品位高,起爆至368℃的区间无峰的矿化好;初步认为该区在180m中段以下的19~31线和3—11线会出现金品位的高值区。 相似文献
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OBJECTIVE: To study the clinical characteristics, treatment outcome, and complications of patients with adult onset Still's disease (AOSD) in our local Chinese population. METHODS: Patients with AOSD were identified among others who attended our rheumatology clinics from 1967 to 1997 and were followed. Their clinical and laboratory features at presentation, treatment, and outcome were recorded and compared with other reported series. RESULTS: Sixteen patients with AOSD were identified. Eleven (69%) were female. Nine (56%) had onset of the disease between 16 and 35 years of age. The commonest presenting features were fever (100%), arthritis (94%), rash (85%), weight loss (69%), and sore throat (63%). Fifteen patients presented with pyrexia of unknown origin and the median duration of fever before the establishment of the diagnosis was 6 weeks (range 4-75). The acute phase response was marked in all patients with gross elevation of erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and complement levels. Hyperferritinemia (> 5 times normal) was present in 90% of cases. Most patients (81%) required corticosteroid therapy and 85% of those steroid treated patients received additional disease modifying agents. The mean duration of followup of our patients was 93.3 months (range 8-362). Five (33%) had monocyclic systemic disease, 6 (40%) had polycyclic systemic disease, and 4 (27%) had frequent relapses that progressed to a chronic arthropathy. CONCLUSION: AOSD in southern Chinese tends to run a benign course, with few patients evolving into chronic inflammatory arthropathy. A significantly lower incidence of serositis, lung involvement, and enlargement of the reticuloendothelial organs was observed at presentation compared with patients of different ethnic origins. 相似文献
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鹿儿坝金矿床是西秦岭地区的一处中型金矿床,赋矿围岩主要为中三叠统光盖山组长英砂岩、粉砂岩及粉砂质板岩等。在对矿床野外地质特征、矿石矿物组成、矿石结构构造、成矿元素组合详细研究的基础上,认为该区金矿体主要受近EW向脆性断裂构造控制,与闪长玢岩脉关系密切;矿石中金属矿物主要为黄铁矿、毒砂、辉锑矿、闪锌矿;石英、黄铁矿、毒砂为主要载金矿物,矿石类型主要有蚀变构造角砾岩型、蚀变闪长玢岩型、脉状及浸染状硫化物型、褐铁矿化碎裂岩型;流体测温、矿物组合及蚀变特征显示本区为中低温热液金矿床;硫、铅同位素研究结果表明,成矿物质具有深源特征。结合区域矿床研究结果,认为鹿儿坝金矿床形成于印支末期,为与闪长岩脉有关的斑岩型-蚀变岩型金矿床,矿床剥蚀深度较浅,目前所见到金矿体可能大部分为闪长玢岩脉(体)上部破碎带中的蚀变岩型金矿床,深部具有较大的成矿和找矿潜力。 相似文献
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This study identified several group characteristics from group composition and process perspectives and examined their relationships with group performance over time. A longitudinal laboratory experiment was conducted to evaluate influences of preference for group work and perceptions of heterogeneity, group potency, and outcome expectation on performance of 31 student work groups performing decision-making tasks. Results of partial least squares analysis indicated that preference for group work and perception of group potency were the strongest predictors of group performance at both Time 1 and Time 2. These variables were found to be stable over time. Results also indicated that group members' perception of outcome expectation were reinforced by their groups' initial performance. Implications of these results for implementing group-based work systems and conducting group research are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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Forty-four goats were milked and milk flow recorded without or with 1 min manual prestimulation in early, mid and late lactation. Ultrasound measurements of cross sections of the whole mammary gland were performed in a water bath. In additional experiments with 15 goats, milk flow was recorded and frequent blood samples were taken for the determination of oxytocin and prolactin concentrations. Milk yield increased from the first to the third lactation and decreased markedly during the course of lactation. Average and peak milk flow rates were closely related to the actual milk yield. The ultrasound cisternal area was 27.4 +/- 1.5% of the entire udder half cross section. Milking characteristics were scarcely different without or with prestimulation, although oxytocin was released within 30 s after the start of prestimulation, whereas oxytocin concentrations without prestimulation increased only after the start of milking. Concentrations of prolactin were higher during July and August than in April, and increased similarly with or without prestimulation during milking. In contrast to dairy cows, prestimulation and an opportune release of oxytocin during milking does not significantly influence the course of milk flow in goats, and this is probably because large amounts of cisternal milk allow milk ejection to be induced only after the start of milking without causing bimodal or otherwise reduced milk flow. 相似文献
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This study examined how specific features of adaptive tests are related to test takers' reactions. Participants took a computer-adaptive test in which 2 features, difficulty of the initial item and difficulty of subsequent items, were manipulated, then responded to questionnaires assessing their reactions to the test. The data show that the relationship between a test's objective difficulty, which was determined by the 2 manipulated test characteristics, and reactions was fully mediated by perceived performance. Additional analyses evaluated the impact of feedback on reactions to the adaptive test. In general, feedback that was consistent with perceptions of performance was positively related to reactions. The results suggest that minor changes to the design of an adaptive test may potentially enhance examinees' reactions, (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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Analyzed the perceived importance of 9 job characteristics relevant to the job satisfaction of 72 PhD research biologists. A majority gave primary importance to personal and professional achievement factors. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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Discusses the cognitive-behavioral and academic functioning of children with epilepsy, the effects of anticonvulsant medications and other peri-ictal phenomena, and their relative impact on cognitive functioning and school achievement. Learning problems often occur in children with epilepsy, with the greatest difficulties in arithmetic, spelling, reading comprehension, and word recognition. Epileptic children also tend to experience more problems in overall achievement, concentration, and mental processing than nonepileptic children. While epileptic children tend to fall within the normal range of IQ, the distribution of their scores is skewed toward the lower level of functioning. Peri-ictal phenomena can effect brain discharges, which can thereby effect concentration, attention, and learning ability. Anticonvulsant medications have potentially negative side effects on neuropsychological functioning as well. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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98 children in 3 open and 3 traditional 1st-grade classrooms were observed and tested on physiological and performance measures (e.g., Star and Pyramid Mazes) at the beginning and end of their 1st yr of school. Skin conductance level and mean pulse rate were used to categorize subgroups as either high or low in physiological arousal level. It was predicted that the greater amount of external stimulation in an open classroom would provide a more suitable learning environment for low-arousal Ss in that their needs for stimulation would be satisfied and their behavioral manifestations of an arousal deficit would be reduced; the opposite was expected for high-arousal Ss. ANOVAs revealed that performance (e.g., visual discrimination scores) of high-arousal Ss in open classrooms decreased over time in contrast to all other S subgroups. (14 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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Degassed excised rat lungs were ventilated in a water-filled plethysmograph with the carina as the zero pressure reference. Pressure-volume curves were recorded from a minimum transpulmonary pressure (Pmin) of -5 cmH2O to a maximum pressure (Pmin) of 30 cmH2O. An index of the minimun volume for the lung (Vm) divided by the maximum lung volume for the same cycle (Vmax) was used as an index of the amount of air trapped within the lung. As the flow rate was decreased from 38.2 to 1.9 ml/min, there were significant increases in the amount of air trapped in the lung. As the maximum pressure was decreased to 25 and 20 cmH2O, or the minimum pressure was increased to 6 and 11 cmH2O, the amount of trapped air in the lung significantly decreased. The rate of lung inflation had a much greater influence on the amount of trapped air than either the deflation rate or stress relaxation. The results are consistent with the theory that bubbles are formed during inflation and are the main cause of air trapped in the excised lung. 相似文献