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Jaymee R. Shell Shawn M. K. Robbins Philippe C. Dixon Philippe J. Renaud René A. Turcotte Tom Wu 《Sports biomechanics / International Society of Biomechanics in Sports》2017,16(3):313-324
The forward skating start is a fundamental skill for male and female ice hockey players. However, performance differences by athlete’s sex cannot be fully explained by physiological variables; hence, other factors such as skating technique warrant examination. Therefore, the purpose of this study was to evaluate the body movement kinematics of ice hockey skating starts between elite male and female ice hockey participants. Male (n = 9) and female (n = 10) elite ice hockey players performed five forward skating start accelerations. An 18-camera motion capture system placed on the arena ice surface captured full-body kinematics during the first seven skating start steps within 15 meters. Males’ maximum skating speeds were greater than females. Skating technique sex differences were noted: in particular, females presented ~10° lower hip abduction throughout skating stance as well as ~10° greater knee extension at initial ice stance contact, conspicuously followed by a brief cessation in knee extension at the moment of ice contact, not evident in male skaters. Further study is warranted to explain why these skating technique differences exist in relation to factors such as differences in training, equipment, performance level, and anthropometrics. 相似文献
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Self-biases are well described in adults but remain poorly understood in children. Here, we investigated in 6–10 year-old children (N = 132) the self-prioritization effect (SPE), a self-bias which reflects, in adults, the perceptual advantage for stimuli arbitrarily associated with the self as compared to those associated with other persons. We designed a child-friendly adaptation of a paradigm originally introduced in adults by Sui, He, and Humphreys (2012) in order to test whether the SPE also occurs in children and if so, to determine its evolution with age. A robust SPE was obtained from the age of 6, and this effect was similar-sized in our four age groups. These findings are discussed with reference to the development of the self during childhood. 相似文献
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We present a microfluidic device capable of separating platelets from other blood cells in continuous flow using dielectrophoresis field-flow-fractionation. The use of hydrodynamic focusing in combination with the application of a dielectrophoretic force allows the separation of platelets from red blood cells due to their size difference. The theoretical cell trajectory has been calculated by numerical simulations of the electrical field and flow speed, and is in agreement with the experimental results. The proposed device uses the so-called "liquid electrodes" design and can be used with low applied voltages, as low as 10 V(pp). The obtained separation is very efficient, the device being able to achieve a very high purity of platelets of 98.8% with less than 2% cell loss. Its low-voltage operation makes it particularly suitable for point-of-care applications. It could further be used for the separation of other cell types based on their size difference, as well as in combination with other sorting techniques to separate multiple cell populations from each other. 相似文献
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The majority of studies reporting gains in college students’ critical thinking due to instructional process variables measured critical thinking with subject-specific questions rather than general or decontextualized questions. However, it is uncertain whether these gains were attributable to the use of subject-specific questions or to other distinctive aspects of these studies (e.g., methodological). The present study provides a direct, controlled comparison between general and subject-specific test questions in the context of a laboratory-based true experiment assessing the effect of higher order review questions on gains in critical thinking. A stronger effect was found when the tests of critical thinking contained questions that were subject-specific (e.g., introductory psychology) rather than questions that focused on general topics. 相似文献
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Philippe J. Renaud Shawn M. K. Robbins Philippe C. Dixon Jaymee R. Shell René A. Turcotte David J. Pearsall 《Sports Engineering》2017,20(4):255-266
The forward skating start is a fundamental skill for ice hockey players, yet extremely challenging given the low traction of the ice surface. The technique for maximum skating acceleration of the body is not well understood. The aim of this study was to evaluate kinematic ice hockey skating start movement technique in relation to a skater’s skill level. A 10-camera motion capture system placed on the ice surface recorded “hybrid-V” skate start movement patterns of high and low calibre male ice hockey players (n = 7, 8, respectively). Participants’ lower body kinematics and estimated body centre of mass (CoM) movement during the first four steps were calculated. Both skate groups had similar lower body strength profiles, yet high calibre skaters achieved greater velocity; skating technique differences most likely explained the performance differences between the groups. Unlike over ground sprint start technique, skating starts showed greater concurrent hip abduction, external rotation and extension, presumably for ideal blade-to-ice push-off orientation for propulsion. Initial analysis revealed similar hip, knee and ankle joint gross movement patterns across skaters, however, further scrutiny of the data revealed that high calibre skaters achieved greater vertical CoM acceleration during each step that in turn allowed greater horizontal traction, forward propulsion, lower double-support times and, accordingly, faster starts with higher stride rates. 相似文献
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The Interrelation of First-Year College Students’ Critical Thinking Disposition, Perceived Academic Control, and Academic Achievement 总被引：2，自引：0，他引：2
Robert H. Stupnisky Robert D. Renaud Lia M. Daniels Tara L. Haynes Raymond P. Perry 《Research in higher education》2008,49(6):513-530
While a great deal of research has examined students’ critical thinking skills, less is known about students’ tendencies to
use these skills. Specifically, little is known about what factors contribute to students developing a disposition to think
critically or what impact this disposition has on college students’ academic achievement. Perceived control, which has been
found to be an important factor in college students’ academic success, may be an important factor in developing this disposition.
The current longitudinal study examined the reciprocal-effects between critical thinking disposition and perceived academic
control, and their comparative influences on academic achievement in 1196 first-year college students. Using a two-wave, two-variable
cross-lag structural equation model, a reciprocal-effect was found whereby students’ perceived academic control predicted
their subsequent critical thinking disposition, and students’ critical thinking disposition predicted their subsequent perceived
academic control. Furthermore, after controlling for high school academic performance, perceived academic control was found
to have a stronger impact on students’ GPAs than critical thinking disposition. Implications of fostering a critical thinking
disposition and perceived academic control among college students are discussed.
相似文献
| Robert H. StupniskyEmail: |
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Magnetophoretic manipulation in microsystem using carbonyl iron-polydimethylsiloxane microstructures
Magalie Faivre Renaud Gelszinnis Jér?me Degouttes Nicolas Terrier Charlotte Rivière Rosaria Ferrigno Anne-Laure Deman 《Biomicrofluidics》2014,8(5)
This paper reports the use of a recent composite material, noted hereafter i-PDMS, made of carbonyl iron microparticles mixed in a PolyDiMethylSiloxane (PDMS) matrix, for magnetophoretic functions such as capture and separation of magnetic species. We demonstrated that this composite which combine the advantages of both components, can locally generate high gradients of magnetic field when placed between two permanent magnets. After evaluating the magnetic susceptibility of the material as a function of the doping ratio, we investigated the molding resolution offered by i-PDMS to obtain microstructures of various sizes and shapes. Then, we implemented 500 μm i-PDMS microstructures in a microfluidic channel and studied the influence of flow rate on the deviation and trapping of superparamagnetic beads flowing at the neighborhood of the composite material. We characterized the attraction of the magnetic composite by measuring the distance from the i-PDMS microstructure, at which the beads are either deviated or captured. Finally, we demonstrated the interest of i-PDMS to perform magnetophoretic functions in microsystems for biological applications by performing capture of magnetically labeled cells. 相似文献
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One way to assess the quality of education in post-secondary institutions is through the use of performance indicators. Studies
that have compared currently popular process indicators (e.g., library size, percentage of faculty with PhD) found that after
controlling for incoming student ability, these process indicators tend to be weakly associated with student outcomes (Pascarella
and Terenzini, 2005). In addition, while much research has found that students increase their critical thinking skills as
a result of attending college, little is known about what goes on during the college experience that contributes to this.
The purpose of this research was to examine the validity of higher-order questions on tests and assignments as a process indicator
by comparing it with gains in critical thinking skills among college students as an outcome indicator. The present research
consisted of three studies that used different designs, samples, and instruments. Overall, it was found that frequency of
higher-order questions can be a valid process indicator as it is related to gains in students’ critical thinking skills. 相似文献