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121.
Klika RJ Alderdice MS Kvale JJ Kearney JT 《Journal of strength and conditioning research / National Strength & Conditioning Association》2007,21(1):265-269
The efficacy of an 8-minute field test to prescribe exercise intensity and assess changes in fitness was evaluated before and after 8 weeks of indoor cycling, and the results were confirmed by laboratory assessment. Changes in maximal steady-state power (MSSP), power at lactate threshold (PT(lact)), maximal power (Pmax), and maximal oxygen uptake (VO2max) were measured on 56 participants (20 women, 36 men; mean +/- SD. 46.5 +/- 10.0 years) who completed 1-hour, biweekly indoor stationary cycling classes on their own road bike outfitted with a Power Tap Pro power meter. The MSSP was defined as the average power during an 8-minute field test, which was administered at the beginning (pre) and end (post) of the training intervention. Individual training ranges were calculated from the pre-MSSP in accordance with Carmichael Training Systems. Laboratory assessments of PT(lact), Pmax, and VO2max were made on 24 of the participants the same weeks MSSP was evaluated. After training, MSSP increased 9.2% (195.4 +/- 56.6 vs. 213.8 +/- 57.2 W; p < 0.05), and PT(lact) increased 12.9% (178.3 +/- 47.1 vs. 201.5 +/- 47.6 W; p < 0.05). The MSSP was approximately 7.5 % higher than PT(lact). Pmax increased approximately 6.7% (315.2 +/- 65.1 to 336.5 +/- 65.9 W), and VO2max increased approximately 6.5% (46.2 +/- 10.7 to 49.1 +/- 10.5 ml x kg(-1) x min(-1)). The MSSP and PT(lact) were highly correlated (r = 0.98) as was MSSP and VO2max (r = 0.90). The results of this research indicated that (a) the field test is a valid measure of fitness and changes in fitness, (b) it provided data for the establishment of training ranges, and (c) a biweekly power-based training program can elicit significant changes in fitness. 相似文献
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采用非洲爪蟾卵提取物非细胞体系,以外源Lambda DNA诱导细胞核的体外组装,以此实验模式为基础,研究了细胞核体外组装过程中核纤层的组装,结果表明核纤层蛋白参与细胞核的体外组装过程,核内骨架的组装与核纤层的组装在时间上是有序的,核内骨架的组装可能为核纤层的装配提供了先决条件.在非洲爪蟾卵提取物非细胞体系中加入抗核纤层蛋白抗体,抑制核纤层的正常装配过程,核膜组装发生异常.结果提示核纤层的组装与核膜的组装是密切相关的. 相似文献
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昆虫抗药性和昆虫毒理动力学(英文) 总被引:1,自引:0,他引:1
不断地使用一种杀虫药剂防治昆虫,会导致昆虫产生抗药性。对昆虫抗药性资料进行广泛综述时,发现了仅单独的解毒作用不能被解释为家蝇对有机氯杀虫药剂产生高抗性原因。作为一个基因。家蝇可以对有机氯产生比对有机磷杀虫剂更高的抗药性,尽管有机磷杀虫剂一般在虫体内是不太稳定的。考虑到昆虫毒理的动力学,杀虫药剂的穿透作用更显示出其实际的重要性。根据穿透和解毒的速率,慢的穿透作用是解毒作用的一个限制因子。防治敏感和抗性昆虫的观察结果,可以划出物理和生物因子之间关系的几种相关曲线图解。这些相关性不仅能说明家蝇对有机磷和有机氯杀虫剂的抗性程度,而且也助于选择出新的杀虫毒剂。 相似文献
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Measurement on Camber Deformation of Wings of Free-flying Dragonflies and Beating-flying Dragonflies
Deqiang Song Lijiang Zeng . State Key Laboratory of Precision Measurement Technology Instruments Tsinghua University Beijing P.R. China . Gilman Dr. University of California San Diego CA USA 《仿生工程学报(英文版)》2004,1(1):41-45
1 IntroductionNumerouskinematicparameters,includingwing beatfrequency ,wingorientation ,andbothspan andchord wisedeformation ,arerelevanttotheaerodynam icanalysisofinsectflight[1,2 ] .Althoughnearlyalltherecentstudiesofinsectflightaerodynamics[3,4 ] haveidentifiedthatthemechanismsrequireflowseparationattheleadingedge ,andcamberisnotexpectedtohaveanysignificantinfluenceonthemagnitudeoftheforcecoefficient,someinsects ,suchasdragonfliesandbut terflies,frequently glideusinglowanglesofattack ,lead… 相似文献
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