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41.
This paper presents a novel sensor technology to deduce the dynamics of a bowling ball. The sensor, a miniature wireless inertial measurement unit (IMU), incorporates MEMS accelerometers and angular rate gyros, a microcontroller, a low power RF transceiver, and a rechargeable battery. When embedded in a bowling ball, the IMU transmits the acceleration and angular velocity data that define the dynamics of the ball starting with the bowler’s delivery and its motion in the lane. Example results from professional bowlers illustrate how this technology can be used to assess bowler skill and ball performance. For instance, the IMU accurately measures the spin dynamics of the ball which are crucial to develop the ball “hook.” An analysis of ball dynamics in the lane is distilled to a measurable “hook potential” metric for further assessing bowler skill. Finally, the sensor presented herein is believed to be the world’s smallest, wireless IMU. This highly miniaturized and wireless design will enable parallel training systems for many sports, including basketball, baseball, crew, cricket, golf, fly fishing, soccer, softball, tennis, rowing, among others.  相似文献   
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It is argued that online discussion is a useful tool for creating opportunities for learning in teacher education. In a project designed to improve the practicum in rural areas, researchers placed pre-service teachers (PSTs) in two different moderated online discussion forums: an unstructured personal blog space and a structured threaded discussion forum where discussion topics guided them to reflect on their practicum experiences in relation to theoretical components of their studies. Findings indicated a marked difference in the contributions made to each form of online discussion with significantly greater participation in the unstructured blog format. Using Kreber and Cranton’s hierarchy of reflection, analyses of both forums found that PSTs rarely engaged in high-level reflection. Examination of lecturer involvement in the forums suggests that their contributions did not sufficiently encourage PSTs towards optimum critical reflection. These results leave the researchers considering ways in which the practicum experience can better promote reflective practice in this crucial, component of teacher education.  相似文献   
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The majority of eukaryotic genes produce multiple mRNA isoforms with distinct 3′ ends through a process called mRNA alternative polyadenylation (APA). Recent studies have demonstrated that APA is dynamically regulated during development and in response to environmental stimuli. A number of mechanisms have been described for APA regulation. In this review, we attempt to integrate all the known mechanisms into a unified model. This model not only explains most of previous results, but also provides testable predictions that will improve our understanding of the mechanistic details of APA regulation. Finally, we briefly discuss the known and putative functions of APA regulation.  相似文献   
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The aim of the present study was to examine the relationship between the performance heart rate during an ultra-endurance triathlon and the heart rate corresponding to several demarcation points measured during laboratory-based progressive cycle ergometry and treadmill running. Less than one month before an ultra-endurance triathlon, 21 well-trained ultra-endurance triathletes (mean +/- s: age 35 +/- 6 years, height 1.77 +/- 0.05 m, mass 74.0 +/- 6.9 kg, = 4.75 +/- 0.42 l x min(-1)) performed progressive exercise tests of cycle ergometry and treadmill running for the determination of peak oxygen uptake (VO2peak), heart rate corresponding to the first and second ventilatory thresholds, as well as the heart rate deflection point. Portable telemetry units recorded heart rate at 60 s increments throughout the ultra-endurance triathlon. Heart rate during the cycle and run phases of the ultra-endurance triathlon (148 +/- 9 and 143 +/- 13 beats x min(-1) respectively) were significantly (P < 0.05) less than the second ventilatory thresholds (160 +/- 13 and 165 +/- 14 beats x min(-1) respectively) and heart rate deflection points (170 +/- 13 and 179 +/- 9 beats x min(-1) respectively). However, mean heart rate during the cycle and run phases of the ultra-endurance triathlon were significantly related to (r = 0.76 and 0.66; P < 0.01), and not significantly different from, the first ventilatory thresholds (146 +/- 12 and 148 +/- 15 beats x min(-1) respectively). Furthermore, the difference between heart rate during the cycle phase of the ultra-endurance triathlon and heart rate at the first ventilatory threshold was related to marathon run time (r = 0.61; P < 0.01) and overall ultra-endurance triathlon time (r = 0.45; P < 0.05). The results suggest that triathletes perform the cycle and run phases of the ultra-endurance triathlon at an exercise intensity near their first ventilatory threshold.  相似文献   
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Current developments in tertiary education settings are resulting in a second wave of academics using on-line technologies in their teaching, providing universities with a considerable professional staff development challenge. The case study presented here illustrates one way of responding to this challenge. Overall, the literature suggests that professional development that is discipline-specific and located in a community-of-practice is more likely to be relevant and productive than a centralized, decontextualized approach. We propose an alternative hybrid model of 'professional engagement' for on-line teaching that attempts to build on existing discipline-specific workplace structures. This includes recruiting academic on-line teaching advisers for each school in the faculty, showcasing existing exemplary practice, and setting up 'professional engagement groups' with a support team. The main advantages of the model are its responsiveness to patterns of academic work and to the immediate needs of academics, the way it enhances the visibility of exemplars of academic work, its cost-effectiveness and scalability, and the complementarity of local and centralized support systems. Limitations include the time needed to build up such staff engagement, an apparent lack of visibility, and difficulty in measuring outcomes.  相似文献   
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