Immediate effects of the use of modified take-off boards on the take-off motion of the long jump during training     

Koyama H  Muraki Y  Ae M 《Sports biomechanics / International Society of Biomechanics in Sports》2006,5(2):139-153

We investigated the immediate effects of the combined use of inclined and raised flat boards on the take-off motion of the long jump. Eight male long jumpers were videotaped with two high-speed video cameras (250 Hz) set perpendicular to the runway. The athletes jumped with three modified take-off boards: upward-inclined boards of two different inclinations (2.5 and 5.0 degrees), and a raised flat board (50 mm high). The jumpers performed pre- and post-jumps using their own techniques before and after use of the boards to test their effects. The post- jump revealed significantly less reduction in the horizontal velocity during the take-off than the pre-jump, and the effectiveness of converting the velocity from horizontal to vertical increased significantly in the post-jump. The post-jump demonstrated significantly less knee flexion of the take-off leg during take-off. The reduced knee flexion and slower extension velocity of the take-off leg in the second phase of the post-jump contributed to increasing the knee extension torque in the second phase and resulted in the increases in vertical ground reaction force and vertical velocity. These results suggest that the combined use of the inclined and raised flat boards induced immediate effective changes in the kinematics and kinetics of the take-off motion and represent appropriate training tools for take-off techniques of the long jump.  相似文献   

Low-intensity electrical muscle stimulation induces significant increases in muscle strength and cardiorespiratory fitness     

Toshiaki Miyamoto  Hiroyuki Kamada  Akira Tamaki  Toshio Moritani 《European Journal of Sport Science》2016,16(8):1104-1110

The aim of this study was to investigate the effect of low-intensity exercise training using belt electrode skeletal muscle electrical stimulation on muscle strength and cardiorespiratory fitness in healthy subjects. Nineteen healthy subjects were allocated into control or intervention groups; in both groups the participants kept regular physical activity while the intervention group underwent 30 min B-SES training at 3–4 METs for four weeks. Knee extensor muscle strength and cardiorespiratory endurance during incremental exercise test were measured at baseline and after four weeks for all participants. The relative change of knee extensor muscle strength in the intervention group was significantly higher than control group (p?p?相似文献   

Armageddon and pedagogy of terror     

Morimichi Kato 《Educational Philosophy and Theory》2020,52(8):836-837

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Significance of the rhetorical and humanistic tradition for education today     

Morimichi Kato 《Asia Pacific Education Review》2014,15(1):55-63

This article intends to illuminate the educational significance of the rhetorical and humanistic tradition. This tradition exerted a great influence upon Western education in the past, but its significance has been largely overlooked by the current philosophy of education. This is probably owing to the centuries-old prejudice against rhetoric and “pedantry” espoused since Plato. Against such criticism, this article intends to defend the educational value of the rhetorical and humanistic tradition by retrieving three essential features as noted by its major theorists—Protagoras (ca. 490–420 B.C.), Cicero (106–43 B.C.), and Leonardo Bruni (1370–1444). These features include public spiritedness, a broader understanding of language, and multi-perspective knowledge. Protagoras, Cicero, and Bruni (each in their own historical context) criticized the closed attitude of philosophers toward monopolizing truth and stood in favor of the public sphere where important matters could be openly discussed. Second, they criticized the philosophical understanding of language as a mirror that represents truth and presented a wider understanding of language that considers the speaker–listener relationship. Third, they developed their concept of multi-perspective knowledge, which was opposed to the philosophical knowledge directed toward a special object, as seen in the Platonic Ideas. The re-evaluation of these three features is absolutely necessary if we wish to rescue the rhetorical and humanistic tradition from the blame of parochial chauvinism. By retrieving these features, the rhetorical and humanistic tradition can help to make contemporary education more publicly open (less closed to specialists), more sensitive to the power of language, and more appropriate within the multi-cultural and multi-lingual experience of the modern world.  相似文献   

Lipid peroxidation and antioxidant vitamins in urolithasis     

J Kato  Alice Abraham Ruram  S Sekharjit Singh  S Bilasini Devi  Th Ibetombi Devi  W Gyaneshwar Singh 《Indian journal of clinical biochemistry : IJCB》2007,22(1):128-130

The present, study was conducted to determine the level of malondialdehyde (MDA) as an index of free radial induced lipid peroxidation and antioxidant vitamins-vitamins A, vitamin C and vitamin E in 75 confirmed cases of urolithiasis. Significantly high level of MDA (p<0.001) with significantly low levels of vitamin E (p<0.001) and vitamin A (p<0.001) with no significant decrease in vitamin C (p>0.05) were observed in the plasma of urolithiasis cases as compared to normal controls. In conclusion, it appears that a role of lipid peroxidation and oxidative function exists in the pathogenesis of urolithiasis. But, the exact mechanism how this occurs remains to be elucidated.  相似文献   

Piaget’s constructivism and childhood education in Japan     

Yasuhiko Kato  Constance Katnii 《Prospects》2001,31(2):209-220

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汉语“站立”义词的现状与历史   总被引：7，自引：0，他引：7  

汪维辉  秋谷裕幸 《中国语文》2010,(4)

表示站立意义的词属于人类语言的基本词。本文描述汉语站立义词的现实分布和历时演变,并尝试对两者的关系作出解释。现代方言中表站立义的主导词有3个:站、立、徛。它们的分布特点是:站分布最广,大多数北方方言说站,此外还散见于非官话区的部分方言点;徛密集分布于东南部的吴语、徽语、赣语、湘语、客家话、广西平话、粤语、闽语地区;立则呈零散分布,散落在官话、晋语、吴语、赣语、湘语、湖南乡话和广西平话各区。这3个词在汉语史上的情况大致是:立从有文字记载的上古早期起一直是影响最大的通语词,直到明代以后才在大部分北方地区被站替换;徛(倚)用作站立义始见于战国,历史上可能作为一个方言词一直存在于南部广大地区;站始见于唐代,明代以后在广大的官话区逐渐取代立成为新的通语词。站很可能是所谓的长江型词,即兴起于江淮流域而后往北扩散。  相似文献   

Novel mathematical model to estimate ball impact force in soccer     

Takahito Iga  Hiroyuki Nunome  Shinya Sano  Nahoko Sato  Yasuo Ikegami 《Sports biomechanics / International Society of Biomechanics in Sports》2018,17(4):477-493

To assess ball impact force during soccer kicking is important to quantify from both performance and chronic injury prevention perspectives. We aimed to verify the appropriateness of previous models used to estimate ball impact force and to propose an improved model to better capture the time history of ball impact force. A soccer ball was fired directly onto a force platform (10 kHz) at five realistic kicking ball velocities and ball behaviour was captured by a high-speed camera (5,000 Hz). The time history of ball impact force was estimated using three existing models and two new models. A new mathematical model that took into account a rapid change in ball surface area and heterogeneous ball deformation showed a distinctive advantage to estimate the peak forces and its occurrence times and to reproduce time history of ball impact forces more precisely, thereby reinforcing the possible mechanics of ‘footballer’s ankle’. Ball impact time was also systematically shortened when ball velocity increases in contrast to practical understanding for producing faster ball velocity, however, the aspect of ball contact time must be considered carefully from practical point of view.  相似文献   

Characterization of a-Si:H/SiN multilayer waveguide polarization using an optical pumping application—LED   总被引：1，自引：1，他引：0  

Mohd Saiful Dzulkefly Zan  Isamu Kato  Mohammad Syuhaimi Ab-Rahman  Seri Mastura Mustaza 《浙江大学学报(A卷英文版)》2009,10(10):1421-1427

This paper describes the fabrication of a waveguide and the analysis of its polarization characteristics by applying light-emitting diode （LED） pumping lights to its surface. By using double tubed coaxial line （DTCL） microwave plasma chemical vapor deposition （MPCVD） equipment, an a-Si：H/SiN multilayer waveguide was fabricated whose thickness could be controlled at nanometer order. The main structural material of the waveguide sample consisted of a combination of layers of amorphous silicon hydrogen and silicon nitrate. Once the sample was ready, another major objective of the experiment was to analyze the polarization characteristics of the fabricated waveguide. The idea of the experiment was to analyze how the waveguide reacts when three types of LED （blue, yellow, and red） are radiated onto its surface. The results showed that the fabrication of the a-Si：H/SiN sample is successful. Most effective transmission results, which accord with the polarization characteristics analysis, were obtained.  相似文献   

Segmental dynamics of soccer instep kicking with the preferred and non-preferred leg     

Hiroyuki Nunome  Yasuo IkegamI  Rumi Kozakai  Tommy Apriantono  Shinya Sano 《Journal of sports sciences》2013,31(5):529-541

Abstract

Detailed time-series of the resultant joint moments and segmental interactions during soccer instep kicking were compared between the preferred and non-preferred kicking leg. The kicking motions of both legs were captured for five highly skilled players using a three-dimensional cinematographic technique at 200 Hz. The resultant joint moment (muscle moment) and moment due to segmental interactions (interaction moment) were computed using a two-link kinetic chain model composed of the thigh and lower leg (including shank and foot). The mechanical functioning of the muscle and interaction moments during kicking were clearly illustrated. Significantly greater ball velocity (32.1 vs. 27.1 m · s^?1), shank angular velocity (39.4 vs. 31.8 rad · s^?1) and final foot velocity (22.7 vs. 19.6 m · s^?1) were observed for the preferred leg. The preferred leg showed a significantly greater knee muscle moment (129.9 N · m) than the non-preferred leg (93.5 N · m), while no substantial differences were found for the interaction moment between the two legs (79.3 vs. 55.7 N · m). These results indicate that the highly skilled soccer players achieved a well-coordinated inter-segmental motion for both the preferred and non-preferred leg. The faster leg swing observed for the preferred leg was most likely the result of the larger muscle moment.  相似文献