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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
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In this quasi-experimental mixed methods study, we examined the effectiveness of a faculty-to-faculty mentoring program to increase student success rates in online courses at an American university. Over one semester, 24 faculty mentees worked with 6 faculty mentors on improving course organization and implementing student engagement techniques. Using methodological triangulation, we found positive results for two of our effectiveness measures (i.e., mentor and mentee feedback and mentors’ ratings of mentees’ courses). However, in terms of our third measure (i.e., student learning data), although institutional data showed that there was a 4.1% aggregate increase in online student success after the intervention, the intervention group made no significantly greater gains than two control groups. Our findings highlight some benefits and shortcomings of these types of university initiatives and also emphasize the importance of using triangulation to integrate participant feedback with formal measures of student success. 相似文献
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Jenny Olin Shanahan Elizabeth Ackley-Holbrook Eric Hall Kearsley Stewart Helen Walkington 《Mentoring & Tutoring: Partnership in Learning》2015,23(5):359-376
This paper identifies salient practices of faculty mentors of undergraduate research (UR) as indicated in the extensive literature of the past two decades on UR. The well-established benefits for students involved in UR are dependent, first and foremost, on high-quality mentoring. Mentorship is a defining feature of UR. As more and different types of colleges and universities strive to meet student demand for authentic scholarly experiences, it is imperative to identify what effective UR mentors do in order to ensure student engagement, quality enhancement, retention, and degree-completion. We offer an original analysis of the literature on UR mentoring in which we identify 10 significant “lessons learned,” or evidence-based practices of effective UR mentors that apply broadly across disciplines, students, institutions, and mentoring approaches. 相似文献
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Alexander H. Montoye Karin A. Pfeiffer Darijan Suton Stewart G. Trost 《Measurement in physical education and exercise science》2014,18(4):273-285
The responsiveness to change of the Actical and ActiGraph accelerometers was assessed in children and adolescents. Participants (N = 208) aged 6 to 16 years completed two simulated free-living protocols, one with primarily light-to-moderate physical activity (PA) and one with mostly moderate-to-vigorous PA. Time in sedentary, light, moderate, and vigorous PA was estimated using 8 previously developed cut-points (4 for Actical and 4 for ActiGraph) and 5-sec, 15-sec, and 30-sec epochs. Accelerometer responsiveness for detecting differences in PA between protocols was assessed using standardized response means (SRMs). SRM values ≥.8 represented high responsiveness to change. Both accelerometers showed high responsiveness for all PA intensities (SRMs = 1.2–4.7 for Actical and 1.1–3.3 for ActiGraph). All cut-points and epoch lengths yielded high responsiveness, and choice of cut-points and epoch length had little effect on responsiveness. Thus, both the Actical and ActiGraph can detect change in PA in a simulated free-living setting, irrespective of cut-point selection or epoch length. 相似文献
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