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Abstract Four sprint starting positions—the bunch, medium, elongated, and hyperextended—were compared on mean elapsed times at distances of 10 and 30 yd. Averages of three starts for each of 30 inexperienced college undergraduate males on each type of start were derived from electronically-controlled measures, the times for both distances being recorded from the same start. Statistical analyses indicated significantly lower elapsed times with the hyperextended starting position. 相似文献
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Quantum chemistry is based on the solution of the Schrödinger equation for a molecule. From starting data on the positions and nature of constituent atoms information is provided about the energy of the molecule and its electronic properties. The former can indicate what shapes drugs can adopt in binding to pharmacological receptors whilst electronic details, when compared using computer graphics, may highlight the factors responsible for biological activity. These techniques are beginning to show real successes in the design of drug molecules. 相似文献
116.
G. A. Alabi 《Information processing & management》1985,21(6):525-533
This paper presents the results of a comparative cost study of the manual circulation system and experimental automated system in a university library in Nigeria. Two sets of data were collected: one on the existing manual circulation system and the other on the experimental automated system on an Apple II microcomputer. Eight different circulation activities were identified for evaluation for which the direct labor cost of circulating a book on each system was calculated. The experimental automated system was found to be less labor intensive than the manual system, although overall unit cost of book circulation on the automated system was higher than on the manual system ($0.59 and $0.49, respectively). Factors attributed to the higher unit cost on the automated system were the cost of equipment and the low circulation figure. However, the automated system was found to be more effective in providing up-to-date and accurate data required for the monitoring of the library stock. 相似文献
117.
Jeannette A. Colyvas 《Research Policy》2007,36(4):456-476
The formation of Stanford University's technology transfer program in the life sciences is analyzed from 1968 to 1982. The program evolved from multiple models based on divergent definitions of invention, inventor, rewards, and university-industry boundaries. The eventual program that emerged proved to be widely emulated. The norms of the academy shaped the uses of resources and the conditions of their appropriation. In turn, the currency of industrial science prompted the rethinking of academic norms. The analysis offers insight into the early stages of institutionalization, as the ambiguity of important categories and flexibility of policies were transformed into organizational routines. Today's ‘settled’ outcomes are the product of highly divergent practices. 相似文献
118.
Treatment practices for childhood posttraumatic stress disorder 总被引:4,自引:0,他引:4
OBJECTIVE: This study surveyed practices in treating childhood PTSD among child psychiatrists and non-M.D. therapists with self-identified interest in treating traumatized children. METHOD: An anonymous survey was mailed to 207 child psychiatrists ("medical") and 460 nonphysician ("non-medical") therapists inquiring about current interventions used to treat children with PTSD. RESULTS: Two hundred and forty-seven responses were received: of 77 medical and 82 nonmedical respondents who currently treat children with PTSD, a wide variety of modalities are used. Most preferred modalities among medical responders were pharmacotherapy, psychodynamic, and cognitive-behavioral therapy. Most preferred modalities among nonmedical respondents were cognitive-behavioral, family, and nondirective play therapy. Ninety-five percent of medical respondents used pharmacotherapy for this disorder; most preferred medications to treat childhood PTSD were selective serotonin reuptake inhibitors and alpha-adrenergic agonists. Several significant differences between medical and nonmedical practices were identified. CONCLUSIONS: There is little clinical consensus regarding the effectiveness of the many modalities used to treat traumatized children who have PTSD symptoms; empirical research is particularly needed to evaluate the efficacy of pharmacotherapy and EMDR. 相似文献
119.
The present research examined the role of maladaptive self-regulatory beliefs as vulnerability factors for academic and emotional difficulties during the transition to middle school. A short-term longitudinal design was employed to follow two groups of early adolescents: 187 adolescents who experienced a school transition between the fifth and sixth grades, and 142 adolescents who did not experience a school transition between the fifth and sixth grades. Adolescents completed measures of perceptions of academic control and importance of academic success, experience of chronic academic strain, daily school hassles, and depressive symptoms. Teachers reported on students' academic engagement, including levels of helpless behavior, effort, and academic performance. Consistent with the proposed model of self-regulation, maladaptive self-regulatory beliefs (i.e., decreased perceptions of academic control and importance) predicted individual differences in perceived school-related stress and depressive symptoms over the course of the middle school transition, but were not associated with academic and emotional difficulties in adolescents who remained in a stable school environment. Moreover, a self-regulatory sequence was identified proceeding from maladaptive self-regulatory beliefs, to academic disengagement, to enhanced perceptions of school-related stress, to depressive symptoms. This study bridges prior theory and research concerning the psychological impact of normative developmental transitions, the developmental context of depression, and the associations among self-regulatory beliefs, achievement-related behavior, and emotional experience. 相似文献
120.
The peer group as a context for the development of young adolescent motivation and achievement 总被引:14,自引:0,他引:14
Ryan AM 《Child development》2001,72(4):1135-1150
This study investigated the peer group as a context for the socialization of young adolescents' motivation and achievement in school. Social network analysis was used to identify peer groups of adolescents in middle school whose members regularly interacted with each other (N = 331). Actual reports from these peer group members were used to assess peer group characteristics. Multilevel analyses indicated that peer groups did socialize some academic characteristics, controlling for selection factors. Students' peer group context in the fall predicted changes in their liking and enjoyment of school (intrinsic value) and their achievement over the school year. Students' peer group context was unrelated to changes in their beliefs about the importance of school (utility value) or expectancies for success over the school year. 相似文献