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I Stewart L McNaughton P Davies S Tristram 《Research quarterly for exercise and sport》1990,61(1):80-84
It is known that an increased level of red blood cell 2,3-diphosphoglycerate (DPG) shifts the oxyhemoglobin dissociation curve to the right, thus allowing a greater unloading of oxygen at the tissue level. It has been hypothesized that phosphate might help increase VO2max by increasing 2,3-DPG level. Eight trained cyclists underwent three cycle ergometer tests (control, placebo, and experimental) to determine whether phosphate ingestion had any positive effect on VO2max, time to exhaustion, serum 2,3-DPG, and serum phosphate levels. We found no change between the control, placebo, or experimental conditions in pretest serum phosphate levels, but we did find increases in 2,3-DPG levels in the phosphate condition (p less than .05), which suggests that even a small amount of phosphate could increase levels of 2,3-DPG. We also found significant differences in VO2max between the control (p less than .05) and placebo (p less than .02) conditions and also in time to exhaustion between the three conditions (p less than .05). We suggest that phosphate may have an ergogenic effect, but clearly more work needs to be undertaken to ascertain the amount of phosphate required and the magnitude of the effect. 相似文献
965.
Eighteen women participated in a research project involving two phases: (a) an interview regarding weight history and exercise patterns, and (b) a series of exercise sessions followed by discussions of participants' reactions to them. The data were analyzed using inductive analysis techniques, and results of the analysis were discussed with participants for collaborative validation of the interpretation. Profiles of selected participants and themes that emerged are described. The participants varied in age and body size and had diverse backgrounds, interests, and abilities, but their shared experience of social disapproval based on body size was shown to affect their perceptions of exercise programs and their decisions about participation. 相似文献
966.
R J Markert A J Parisi H V Barnes S Cohen K Goldenberg L E Mieczkowski M Dunn R M Siervogel 《Bulletin of the Medical Library Association》1989,77(2):133-138
The experiences of medical students, residents, and faculty with a computerized literature searching system were evaluated. Third-year medical students, internal medicine and family practice residents, and full-time and voluntary faculty at one medical school had the opportunity to use a full-text and bibliographic medical literature retrieval system free of charge for an eleven-month period. Subjects conducted nearly nine thousand literature searches over a period of 942 system hours. Questionnaire data showed that participants could learn to use and would use an electronic information system, felt capable of using the system, utilized the system for a variety of purposes and in a number of different ways, and viewed the system as a valuable tool in searching the medical literature. The results are discussed in the context of the educational needs of the four user-groups and medical education planning by institutions. 相似文献
967.
Carol L. Stuessy 《科学教学研究杂志》1989,26(1):41-53
A model was formulated and tested for the development of scientific reasoning abilities in adolescents. Piagetian theory provided the framework for choosing potential determinants of the dependent variable, scientific reasoning abilities. A model reflecting hypothesized causal relationships among determinants and with the dependent variable was developed a priori on the basis of theoretical and substantive reasoning. The hypothesized model was tested and revised using path analysis. Data from intact classes of middle-school (n = 101) and high-school (n = 89) students from an upper-middle-class suburb of a midwestern city revealed significant (p < 0.05) path coefficients for these variables and scientific reasoning abilities: age, I.Q., field dependence–independence, and experience. A path from locus of control to scientific reasoning abilities through field dependence-independence was also statistically significant. The revised model explained 61 percent of the variance in scientific reasoning abilities. 相似文献
968.
Raymond W. Kulhavy Mary T. White Bruce W. Topp Ann L. Chan James Adams 《Contemporary educational psychology》1985,10(3):285-291
College undergraduates read a 2400-word passage, responded to 16 multiple-choice questions, and received one of four types of feedback following their responses. Complexity of feedback was inversely related to both error correctability and criterion efficiency taken as a ratio of feedback study time to post-test corrects. The results were discussed in terms of depth of processing and instructional comprehension. 相似文献
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