排序方式： 共有73条查询结果，搜索用时 15 毫秒
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Kohei Watanabe Takayuki Sato Takahiro Mukaimoto Wataru Takashima Michio Yamagishi Tetsunari Nishiyama 《Journal of sports sciences》2016,34(15):1413-1422
We aimed to investigate neuromuscular activation of thigh muscles during track cycling at various speeds. Eight male competitive cyclists volunteered to participate in this study. Surface electromyography of the vastus lateralis, biceps femoris and adductor magnus muscles of the bilateral legs was recorded during track cycling on velodromes with a 250-m track. The participants were instructed to maintain three different lap times: 20, 18 and 16 s. The average rectified value (ARV) was calculated from the sampled surface electromyography. Significantly higher ARVs were observed in the right compared to left leg for the biceps femoris muscle during both straight and curved sections at 18- and 16-s lap times (P < 0.05). In the biceps femoris muscle, significant changes in ARVs during the recovery phase with an increase in speed were seen in the right leg only (P < 0.05). There were no significant differences in ARVs between the straight and curved sections for all three muscles (P > 0.05). From our findings, it was suggested that during track cycling on a velodrome the laterality of the biceps femoris muscle activity is a key strategy to regulate the speed, and fixed neuromuscular strategies are adopted between straight and curved sections for thigh muscles. 相似文献
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A great deal of measurement research is currently being utilized to improve instruction at the elementary and secondary levels, but many opportunities for improving utilization are still untapped. The author proposes specific approaches to increased collaboration between researchers and practitioners to meet the burgeoning research needs of the nations' schools and to assist in data-based decision-making efforts. Society's increasing demands for accurate, usable data have contributed to the urgent current need for viable, appropriate research. This need can be met only by reseachers and practitioners working together to provide answers to critical educational questions. 相似文献
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Shinichi Demura Shunsuke Yamaji Fumio Goshi Hidetsugu Kobayashi Susumu Sato Yoshinori Nagasawa 《Journal of sports sciences》2002,20(2):153-164
The aims of this study were to assess the reliability and validity of three methods of bioelectrical impedance analysis (based on induction between the hand and foot, between one foot and the other foot and between one hand and the other hand) and the skinfold method, and to construct prediction equations for total body density by examining cross-validity in young Japanese adult males. The participants were 50 Japanese males aged 18-27 years (height 1.72 +/- 0.06 m, body mass 64.9 +/- 9.0 kg; mean +/- s), each of whom was measured twice using each of the four methods. Relative body fat based on underwater weighing was used as the criterion for validity. To construct prediction equations for body density, we used multiple regression analysis, whereby all possible combinations were examined. The reliability of all three bioelectrical impedance methods was high (R = 0.999). Three new prediction equations were constructed for the hand-foot method, foot-foot method and skinfold method. The cross-validity of the equations was guaranteed. The relative body fat calculated using the new equations did not differ from that based on the underwater weighing method. 相似文献
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Undergraduate biology education is often viewed as being focused on memorization rather than development of students’ critical-thinking abilities. We speculated that open-note testing would be an easily implemented change that would emphasize higher-order thinking. As open-note testing is not commonly used in the biological sciences and the literature on its effects in biology education is sparse, we performed a comprehensive analysis of this intervention on a primary literature–based exam across three large-enrollment laboratory courses. Although students believed open-note testing would impact exam scores, we found no effect on performance, either overall or on questions of nearly all Bloom’s levels. Open-note testing also produced no advantage when examined under a variety of parameters, including research experience, grade point average, course grade, prior exposure to primary literature–focused laboratory courses, or gender. Interestingly, we did observe small differences in open- and closed-note exam performance and perception for students who experienced open-note exams for an entire quarter. This implies that student preparation or in-test behavior can be altered by exposure to open-note testing conditions in a single course and that increased experience may be necessary to truly understand the impact of this intervention. 相似文献
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Jang K Xu Y Tanaka Y Sato K Mawatari K Konno T Ishihara K Kitamori T 《Biomicrofluidics》2010,4(3):32208
Recently, interest in single cell analysis has increased because of its potential for improving our understanding of cellular processes. Single cell operation and attachment is indispensable to realize this task. In this paper, we employed a simple and direct method for single-cell attachment and culture in a closed microchannel. The microchannel surface was modified by applying a nonbiofouling polymer, 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer, and a nitrobenzyl photocleavable linker. Using ultraviolet (UV) light irradiation, the MPC polymer was selectively removed by a photochemical reaction that adjusted the cell adherence inside the microchannel. To obtain the desired single endothelial cell patterning in the microchannel, cell-adhesive regions were controlled by use of round photomasks with diameters of 10, 20, 30, or 50 μm. Single-cell adherence patterns were formed after 12 h of incubation, only when 20 and 30 μm photomasks were used, and the proportions of adherent and nonadherent cells among the entire UV-illuminated areas were 21.3%±0.3% and 7.9%±0.3%, respectively. The frequency of single-cell adherence in the case of the 20 μm photomask was 2.7 times greater than that in the case of the 30 μm photomask. We found that the 20 μm photomask was optimal for the formation of single-cell adherence patterns in the microchannel. This technique can be a powerful tool for analyzing environmental factors like cell-surface and cell-extracellular matrix contact. 相似文献
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Intersample optimization in a sampled-data control system using the redundancy of a dual-rate system
The present study discusses the design method for controlling a single-input/single-output linear time-invariant dual-rate system, where the sampling interval of the plant output is longer than the holding interval of the control input. In such a dual-rate system, the intersample output might oscillate even when the sampled output converges to the reference input in the steady state. In a conventional ripple-free method, an existing control law is extended by introducing an exogenous variable, which is independent of the discrete-time sampled response, and the exogenous variable is designed for eliminating the steady-state intersample ripples without changing the existing sampled response. In another method, since a control law is designed such that the intersample performance is optimized, the intersample ripples are eliminated in the transient as well as steady states. However, the preservation of an existing sampled response is not taken into account. The present study proposes a new design method for eliminating the intersample ripples subject to the existing sampled response. In the proposed method, the continuous-time index is optimized subject to the existing discrete-time response. As a result, the intersample ripples are eliminated in the transient as well as steady states, and the existing discrete-time sampled response is maintained. The proposed method is compared to the conventional dual-rate design methods in numerical examples, and the effectiveness of the method is demonstrated. 相似文献
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佐藤将之 《科学．经济．社会》2021,39(2):114-128
本文旨在阐明《荀子》思想的特质和历史意义,而由此探讨其"天下"观和对当时秦国的看法.借此欲阐明《荀子》一书在战国时代周鲁两国已经不存在的政治情况下成形或出现于世的历史意义.本文先将荀子的"天下"观整理为如下三种特色:其一,荀子所构想的国家从头开始就是治理天下领域的国家.其二,在荀子"天下"观视野下的国家会经过其兴亡的动态.从正面的意义来看,原来只有"方百里"领土的小国理论上也能成长为治理天下的国家.其三,荀子在叙述周朝巩固治理天下的过程中赞扬周公的关键角色,并将他称为"大儒".基于如上三点,荀子在观察秦国的现状之际,认为其威势和领土已经不必要再扩张,而极力鼓励秦廷聘用"大儒"或"聪明君子"来推行"义术",即安抚天下诸侯和人民的政策.荀子一方面似乎认为实际上唯秦国具有在近未来能够治理天下的可能,但借由强调任何领土方圆"一百里"的诸侯只要聘用"大儒"也能够治理天下这一点,提醒秦君别错过聘用他的机会,否则聘用这样人才的其他国家会取代秦国的角色. 相似文献
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20世纪末年郭店楚简等新出土文献问世后,新的知识与见解也随之而来.基于此新知见,对孟子性善论的形成过程有一系列论考.本文即其中探讨《子思子》,特别是中庸篇的部分.中庸篇分为新旧两部分.其中以"中庸"为主题的旧的部分,根据文章形式来看,应该与《缁衣》《表记》《坊记》一样是为子思所作.以"诚"为主题的新的部分,虽然含有部分后世添加的内容,但其思想的架构应该也源自子思,比如,其中有与《性自命出》相同的"性即气"的思考,也有与《五行》相似的天道—人道的思考模式.而孟子在接受这些思想时是有选择的,比如说,子思的"诚"的思想实质上就被孟子抛弃了. 相似文献
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Mochizuki Toshio Nishimori Toshihisa Tsubakimoto Mio Oura Hiroki Sato Tomomi Johansson Henrik Nakahara Jun Yamauchi Yuhei 《Educational technology research and development : ETR & D》2019,67(5):1197-1230
This paper describes the development of a software program that supports argumentative reading and writing, especially for novice students. The software helps readers create a graphic organizer from the text as a knowledge map while they are reading and use their prior knowledge to build their own opinion as new information while they think about writing their essays. Readers using this software can read a text, underline important words or sentences, pick up and dynamically cite the underlined portions of the text onto a knowledge map as quotation nodes, illustrate a knowledge map by linking the nodes, and later write their opinion as an essay while viewing the knowledge map; thus, the software bridges argumentative reading and writing. Sixty-three freshman and sophomore students with no prior argumentative reading and writing education participated in a design case study to evaluate the software in classrooms. Thirty-four students were assigned to a class in which each student developed a knowledge map after underlining and/or highlighting a text with the software, while twenty-nine students were assigned to a class in which they simply wrote their essays after underlining and/or highlighting the text without creating knowledge maps. After receiving an instruction regarding a simplified Toulmin’s model followed by instructions for the software usage in argumentative reading and writing along with reading one training text, the students read the target text and developed their essays. The results revealed that students who drew a knowledge map based on the underlining and/or highlighting of the target text developed more argumentative essays than those who did not draw maps. Further analyses revealed that developing knowledge maps fostered an ability to capture the target text’s argument, and linking students’ ideas to the text’s argument directly on the knowledge map helped students develop more constructive essays. Accordingly, we discussed additional necessary scaffolds, such as automatic argument detection and collaborative learning functions, for improving the students’ use of appropriate reading and writing strategies.
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