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991.
We investigate whether having an advisor of the same gender is correlated with the productivity of PhD science students and their propensity to stay in academic science. Our analysis is based an original dataset – combined from dissertation abstracts, faculty directories and bibliometric data – covering nearly 20,000 PhD graduates and their advisors from U.S. chemistry departments. We find that students working with advisors of the same gender tend to be more productive during the PhD; and that female students working with female advisors are considerably more likely to become faculty themselves. We suggest that the under-representation of women in science and engineering faculty positions may perpetuate itself through the lower availability of same-gender advisors for female students. 相似文献
992.
Lotte L. Lintmeijer Mathijs J. Hofmijster Guido A. Schulte Fischedick Patrick J. Zijlstra A. J. “Knoek” Van Soest 《Journal of sports sciences》2018,36(18):2138-2146
In rowing, mechanical power output is a key parameter for biophysical analyses and performance monitoring and should therefore be measured accurately. It is common practice to estimate on-water power output as the time average of the dot product of the moment of the handle force relative to the oar pin and the oar angular velocity. In a theoretical analysis we have recently shown that this measure differs from the true power output by an amount that equals the mean of the rower’s mass multiplied by the rower’s center of mass acceleration and the velocity of the boat. In this study we investigated the difference between a rower’s power output calculated using the common proxy and the true power output under different rowing conditions. Nine rowers participated in an on-water experiment consisting of 7 trials in a single scull. Stroke rate, technique and forces applied to the oar were varied. On average, rowers’ power output was underestimated with 12.3% when determined using the common proxy. Variations between rowers and rowing conditions were small (SD = 1.1%) and mostly due to differences in stroke rate. To analyze and monitor rowing performance accurately, a correction of the determination of rowers’ on-water power output is therefore required. 相似文献
993.
Patrick J Griffin Richard A. Ferguson Conor Gissane Stephen J. Bailey 《Journal of sports sciences》2018,36(9):1038-1043
This study tested the hypothesis that ischemic preconditioning (IPC) would increase critical power (CP) during a 3 minute all-out cycling test. Twelve males completed two 3 minute all-out cycling tests, in a crossover design, separated by 7 days. These tests were preceded by IPC (4 x 5 minute intervals at 220 mmHg bilateral leg occlusion) or SHAM treatment (4 x 5 minute intervals at 20 mmHg bilateral leg occlusion). CP was calculated as the mean power output during the final 30 s of the 3 minute test with W′ taken as the total work done above CP. Muscle oxygenation was measured throughout the exercise period. There was a 15.3 ± 0.3% decrease in muscle oxygenation (TSI; [Tissue saturation index]) during the IPC stimulus, relative to SHAM. CP was significantly increased (241 ± 65 W vs. 234 ± 67 W), whereas W′ (18.4 ± 3.8 vs 17.9 ± 3.7 kJ) and total work done (TWD) were not different (61.1 ± 12.7 vs 60.8 ± 12.7 kJ), between the IPC and SHAM trials. IPC enhanced CP during a 3 minute all-out cycling test without impacting W′ or TWD. The improved CP after IPC might contribute towards the effect of IPC on endurance performance. 相似文献
994.
The Mobile Reference Service: a case study of an onsite reference service program at the school of public health
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Donghua Tao Patrick G. McCarthy Mary M. Krieger Annie B. Webb 《Medical Library and Historical Journal》2009,97(1):34-40
The School of Public Health at Saint Louis University is located at a greater distance from the library than other programs on the main medical center campus. Physical distance diminishes the ease of access to direct reference services for public health users. To bridge the gap, the library developed the Mobile Reference Service to deliver onsite information assistance with regular office hours each week. Between September 2006 and April 2007, a total of 57 in-depth reference transactions took place over 25 weeks, averaging 2 transactions per week in a 2-hour period. Overall reference transactions from public health users went up 28%, while liaison contacts with public health users doubled compared to the same period the year before. The Mobile Reference Service program has improved library support for research and scholarship, cultivated and strengthened liaison relationships, and enhanced marketing and delivery of library resources and services to the Saint Louis University School of Public Health. 相似文献
995.
996.
Walter Buboltz Jr. Steve M. Jenkins Barlow Soper Kevin Woller Patrick Johnson Theresa Faes 《Journal of College Counseling》2009,12(2):113-124
This study represents an expansion of previous research investigating the prevalence of sleep difficulties in college students. Sleep quality and sleep habits were assessed via self‐report questionnaires. Poor sleep quality was reported by 22.6% of participants, whereas 65.9% replied that they experienced occasional sleep problems. More than half of the respondents noted feeling tired in the morning. Implications for counselors and their institutions are discussed. 相似文献
997.
998.
Kevin L. McKee Lance M. Rappaport Steven M. Boker Debbie S. Moskowitz Michael C. Neale 《Structural equation modeling》2018,25(6):888-905
Damped Linear Oscillators estimated by 2nd-order Latent Differential Equation have assumed a constant equilibrium and one oscillatory component. Lower-frequency oscillations may come from seasonal background processes, which non-randomly contribute to deviation from equilibrium at each occasion and confound estimation of dynamics over shorter timescales. Boker (2015) proposed a model of individual change on multiple timescales, but implementation, simulation, and applications to data have not been demonstrated. This study implemented a generalization of the proposed model; examined robustness to varied timescale ratios, measurement error, and occasions-per-person in simulated data; and tested for dynamics at multiple timescales in experience sampling affect data. Results show small standard errors and low bias to dynamic estimates at timescale ratios greater than 3:1. Below 3:1, estimate error was sensitive to noise and total occasions; rates of non-convergence increased. For affect data, model comparisons showed statistically significant dynamics at both timescales for both participants. 相似文献
999.
Patrick J. Curran Veronica T. Cole Daniel J. Bauer W. Andrew Rothenberg Andrea M. Hussong 《Structural equation modeling》2018,25(6):860-875
Although it is currently best practice to directly model latent factors whenever feasible, there remain many situations in which this approach is not tractable. Recent advances in covariate-informed factor score estimation can be used to provide manifest scores that are used in second-stage analysis, but these are currently understudied. Here we extend our prior work on factor score recovery to examine the use of factor score estimates as predictors both in the presence and absence of the same covariates that were used in score estimation. Results show that whereas the relation between the factor score estimates and the criterion are typically well recovered, substantial bias and increased variability is evident in the covariate effects themselves. Importantly, using covariate-informed factor score estimates substantially, and often wholly, mitigates these biases. We conclude with implications for future research and recommendations for the use of factor score estimates in practice. 相似文献
1000.
Video is increasingly used to support in-service teacher professional development (TPD). Advances in affordability and usability of technology mean that interest is set to develop further. Studies in this area are diverse in terms of scale, methodology and context. This places limitations on undertaking a systematic review; therefore the authors use a scoping review approach. Their analysis involves 82 studies from which they thematise subtopics and assess research characteristics. This provides a much-needed analysis to inform researchers and practitioners. Additionally, the authors identify robust studies that consider the effect of video on teacher cognition and classroom practice. A consistent finding is that video is effective when used as part of TPD. Since studies largely use thematic qualitative analysis, however, this consensus needs further examination. Further qualitative and quantitative research is needed to identify how the use of video impacts on classroom practices. 相似文献