The cumulative and residual fatigue response associated with soccer-specific activity performed on different playing surfaces

ABSTRACT

This study aimed to assess the effect of playing surface (Natural [NT] and Artificial [AT] Turf) on the fatigue response to a soccer-specific exercise protocol (SSEP). Eighteen male soccer players completed the SSEP on NT and AT with pre-, post-, and 48 h post-assessments of eccentric knee flexor (eccKF) and concentric knee extensor peak torque (PT), peak countermovement (CMJ) and squat jump (SJ) height, and Nordic hamstring break angle. No significant main effects for surface or any surface and time interactions were observed for any of the outcome measures, except for eccKF PT recorded at 3.14 rad·s^-1, which was significantly lower 48 h post-trial in the AT condition (AT = 146.3 ± 20.4 Nm; NT = 158.8 ± 24.7 Nm). Main effects for time were observed between pre- and post-trial measures for eccKF PT at all angular velocities, Nordic break angle, CMJ and SJ height. Nordic break angle, and both CMJ and SJ height were significantly impaired 48 h post-trial when compared to pre-trial. The findings of the current study suggest surface dependent changes in eccKF PT which may have implications for recovery and subsequent performance after competition on AT.     

谈科学教学中的有效情境创设

在科学课堂上构建多种有创造性的学习活动情境,诱发学生的好奇心,调动学生的探究动机,鼓励学生大胆并且有效地合作。结合教学实践,提出了多种情境创设途径及教学实例。     

Of Frogs & Rhetoric: The Atrazine Wars

In a scientific dispute over the effects of atrazine on amphibians, chemical industry–funded and publically funded scientists present stunningly contrasting constructions of atrazine's environmental concentrations, persistence, and potential to harm. Considerable scientific uncertainties and variable ranges allow authors to construct preferred versions of the story of atrazine. These incommensurate rhetorical constructions, more the result of competing economic and environmental interests than of any paradigmatic misalignments, have prolonged the dispute not only over atrazine's effects but also over whether its sales should be banned.     

科学技术支撑酒店安全的作用机制与保障体系研究

信息资讯技术的飞跃式发展对现代酒店安全管理提出了巨大的挑战,特别是酒店安全问题越来越受到旅游者的重视,由于显性和隐性的安全隐患来源渠道广泛,使得酒店安全控制与管理变得更为复杂和困难,同时也对酒店安全管理的科技支撑提出越来越高的要求。鉴于此,我们应从酒店安全管理实践的角度出发,对酒店安全管理和科学技术支撑的内在共生性进行分析,构建科学技术支撑酒店安全的作用机制模型,并进一步完善科学技术支撑酒店安全的保障体系,以期能够为酒店安全管理和控制提供一定的借鉴意义,从而促进酒店业的健康、稳定和持续发展。     

Computer,craft, complexity,change: explorations into science teacher knowledge

In this article we review the notion of teacher knowledge from four metaphorical standpoints – teacher knowledge as computer, as craft, as complexity and as change. We employ each of these metaphors to examine and analyse the work of one teacher of science. We draw implications from our analysis for teacher education, teacher development and the study of teaching.     

略论现代社会宗教与科学的关系

在现代社会中 ,科学与宗教的共存状态是一个不争的事实。一方面 ,宗教有其存在的现实基础 ;另一方面 ,科学本身也有它的局限性。两者在不同的领域发挥着各自的作用。     

先进生产力的理论与实现途径

生产力由劳动、劳动对象和劳动资料三个基本要素所构成。先进生产力理论上体现为先进的科学技术与现代化的管理在劳动过程中的统一，可以通过企业生产活动的途陉去实现。发展先进生产力必须坚持先进政党的领导。