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Tae-Whan Kim Sang-Cheol Lee Se-Kee Kil Sung-Chul Kang Young-Tae Lim 《Journal of sports sciences》2017,35(9):835-841
The purpose of the study was to investigate the effect of different kicking modality, i.e., erratic-dynamic target (EDT) versus static target (ST) on the performance of the roundhouse kick in two groups of taekwondo athletes of different skill level. Three-dimensional analysis and surface electromyography (SEMG) analysis were performed on 12 (Group A: six sub-elite, Group B: six elite) athletes to investigate muscle co-activation pattern under two conditions, i.e., EDT versus ST. In the results, the muscle recruitment ratio of the agonistic muscles was higher for Group A, whereas Group B had higher recruitment ratio for antagonist muscles. Overall, the co-activation index (CI) of hip joints appeared higher in the extensors for Group A, whereas higher CI was observed in flexor muscles for Group B with comparatively higher CI during EDT condition than ST condition. Higher value of CI was observed in flexor muscles of the knee joints among Group A during EDT conditions, in contrast, higher CI in the extensor muscles was observed among Group B during ST conditions. In conclusion, the study confirmed that erratic-dynamic movements of target could change the movement coordination pattern to maintain the joint stability of participants. 相似文献
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INTRODUCTION Plants have defense mechanisms against patho-gen infection by inducing systemic resistance in re-sponse to localized pretreatment with biological cotrol agents, thus making them resistant to subsequpathogen infection (Caruso et al., 1999; Hammschmidt, 1999; Mohammadi and Kazemi, 2002; yada et al., 1995; Pozo et al., 2002; Ray et al., 199Biological control of plant pathogens has receivmuch more attention. It is well known that plants amicroorganisms symbiosis is a defense m… 相似文献
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Taekwondo's cultural identity is considered in the light of the controversy over its historical origins. After reviewing several existing theories, the meaning and development of taekwondo as a Korean martial art is explored. There are two conclusions: first, taekwondo is a fusion of several different sources; second, taekwondo is essentially a martial art that focuses on foot skills, and this distinguishes it from Japan's karate and China's wushu, which are primarily based on hand skills. The fact that all terms are rendered into pure Korean words shows the essence of Korean localization. Thus taekwondo incorporates a distinct identity as a Korean martial art. 相似文献
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Namyun Kil 《The Journal of environmental education》2013,44(3):222-236
ABSTRACTThis study examined the effects of vicarious experiences of nature, environmental attitudes, and recreation benefits sought by participants on their support for funding of natural resources and alternative energy options. Using a national scenic trail user survey, results demonstrated that vicarious experiences of nature influenced environmental attitudes and experiential benefits. Support for increased funding allocations was directly influenced by both attitudes and experiential benefits, though attitude was a stronger predictor than benefits. Vicarious educational experiences and funding support were not directly related, but the relationship was mediated via both attitudes and recreation benefits. 相似文献
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This study examined the relationships between family systems and high school students’ career development. Family adaptability
and family cohesion were considered as indicators of family function, and career attitude maturity was conceptualized as a
representative factor explaining adolescents’ career development. A total of 634 high school students participated in this
study. Overall, the results showed that family adaptability and family cohesion were both significant predictors of tenth
graders’ career attitude maturity. The effects of parents’ educational backgrounds on career attitude maturity were negligible.
However, the relationships were inconsistent across gender. For female students, family cohesion was a more influential predictor
of career attitude maturity than family adaptability, while the opposite pattern was observed for the male students. 相似文献
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Zheng Hu-zhe Cui Chun-lan Zhang Yu-ting Wang Dan Jing Yu Kim Kil Yong 《Journal of Zhejiang University. Science. B》2005,6(8):778-786
The activities of enzymes responsible for lignification in pepper, pre-inoculation with arbuscular mycorrhizal (AM) fungus
ofGlomus intraradices and/or infection with pathogenic strain ofPhytophthora capsici, and the biological control effect ofG. intraradices on Phytophthora blight in pepper were investigated. The experiment was carried out with four treatments: (1) plants pre-inoculated
withG. intraradices (Gi), (2) plants pre-inoculated withG. intraradices and then infected withP. capsici (Gi+Pc). (3) plants infected withP. capsici (Pc), and (4) plants without any of the two microorganisms (C). Mycorrhizal colonization rate was reduced by about 10% in
pathogen challenged plants. Root mortality caused by infection ofP. capsici was completely eliminated by pre-inoculation with antagonisticG. intraradices. On the ninth day after pathogen infection, Peroxidase (POD) activity increased by 116.9% in Pc-treated roots but by only
21.2% in Gi+Pc-treated roots, compared with the control, respectively. Polyphenol oxidase (PPO) and Phenylalanine ammonia-lyase
(PAL) activities gradually increased during the first 3 d and dramatically decreased in Pc-treated roots but slightly decreased
in Gi+Pc-treated roots, respectively. On the ninth day after pathogen infection, PPO and PAL decreased by 62.8% and 73.9%
in Pc-treated roots but by only 19.8% and 19.5% in Gi+Pc-treated roots, compared with the control, respectively. Three major
POD isozymes (45000, 53000 and 114000) were present in Pc-treated roots, while two major bands (53000 and 114000) and one
minor band (45000) were present in spectra of Gi+Pc-treated roots, the 45000 POD isozyme was significantly suppressed byG. intraradices, suggesting that the 45000 POD isozyme was induced by the pathogen infection but not induced by the antagonisticG. intraradices. A 60000 PPO isozyme was induced in Pc-treated roots but not induced in Gi+Pc-treated roots. All these results showed the
inoculation of antagonisticG. intraradices alleviates root mortality, activates changes of lignification-related enzymes and induces some of the isozymes in pepper
plants infected byP. capsici. The results suggested thatG. intraradices is a potentially effective protection agent againstP. capsici.
Project supported by Korea Science and Engineering Foundation (KOSEF) through the Agricultural Plants Stress Research Center
(APSRC) at Chonnam National University, Korea 相似文献
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Min Kil Kim James Zhang E. Newton Jackson Jr. Daniel P. Connaughton May Kim 《Measurement in physical education and exercise science》2013,17(3):187-207
Twenty-six male and female collegiate and semiprofessional/professional soccer players (age = 20.4 ± 2.0 years; height = 172.1 ± 8.2 cm; weight = 70.7 ± 10.8 kg) participated in this study to determine the reliability and validity of a field anaerobic shuttle test (FAST) and the Cunningham and Faulkner (1969) treadmill anaerobic speed test (AST). The relationship between the AST and FAST was also investigated. Intraclass reliability coefficients were acceptable for the FAST (.96) and AST (.97) with no significant difference between the means at T1 and T2 (FAST = 56.0 vs. 55.8 sec; AST = 41.9 vs. 41.4 sec). Poor reliability for the Wingate Anaerobic Test (WAT), .83 (W), .70 (W · kg-1), necessitated correcting the validity coefficients for attenuation, FAST vs. WAT = -.89 (W) and -.71 (W · kg-1); AST vs. WAT = .82 (W) and .74 (W · kg-1). These coefficients provide preliminary evidence that the construct being measured is anaerobic work capacity. The results (FAST vs. AST = -.85) indicate that FAST and AST appear to be measuring the same construct. Further research is needed to substantiate the validity of AST and FAST scores as measures of anaerobic work capacity of collegiate and professional soccer players. 相似文献
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Since the introduction of martial arts in the United States, the sport of Taekwondo (TKD) has rapidly grown and developed. Although the elevated interest in this sport has increased the magnitude of the TKD market, no systematic studies have been conducted to investigate the market demand variables associated with TKD schools in North America. To a great extent, lack of study has been due to the unavailability of a viable measure. The purpose of this study was to identify the dimensions of market demand for TKD schools and develop the Scale of Market Demand Associated with Taekwondo School (SMD-TKD). Research participants (N = 205) were TKD school members who were 18 years and older from 22 TKD schools in major cities of Florida. A factor analysis using principal component extraction and varimax rotation produced six factors with 51 items returned (i.e., Personal Benefits, School Operation, Instruction Quality, Program Offering, Locker Room, and Cultural Learning). Multiples regression analysis revealed that all market demand factors, except for Program Offering and Cultural Learning, were positively (p < .05) predictive of TKD consumption, suggesting that the SMD-TKD is useful for marketing studies on TKD consumers. 相似文献
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