Biomechanical characteristics of adults walking forward and backward in water at different stride frequencies

The aim of this study was to examine spatiotemporal characteristics and joint angles during forward and backward walking in water at low and high stride frequency. Eight healthy adults (22.1 ± 1.1 years) walked forward and backward underwater at low (50 pulses) and high frequency (80 pulses) at the xiphoid process level with arms crossed at the chest. The main differences observed were that the participants presented a greater speed (0.58 vs. 0.85 m/s) and more asymmetry of the step length (1.24 vs. 1.48) at high frequency whilst the stride and step length (0.84 vs. 0.7 m and 0.43 vs. 0.35 m, respectively) were lower compared to low frequency (P < 0.05). Support phase duration was higher at forward walking than backward walking (61.2 vs. 59.0%). At initial contact, we showed that during forward walking, the ankle and hip presented more flexion than during backward walking (ankle: 84.0 vs. 91.8º and hip: 22.8 vs. 8.0º; P < 0.001). At final stance, the knee and hip were more flexed at low frequency than at high frequency (knee: 150.0 vs. 157.0º and hip: ?12.2 vs. –14.5º; P < 0.001). The knee angle showed more flexion at forward walking (134.0º) than backward walking (173.1º) (P < 0.001). In conclusion, these results show how forward and backward walking in water at different frequencies differ and contribute to a better understanding of this activity in training and rehabilitation.     

新时期我国中学教育改革及教师队伍建设

以素质教育为核心的教育体制改革,是我国中学教育改革的战略重点。但在从传统的应试教育向素质教育转变的过程中,我们的教师队伍却面临着极大的挑战。如何正视教师队伍中存在的问题,建设一支适应新时代要求的、高素质的教师队伍,是实现这一改革的关键环节。本文从素质教育对教师队伍的要求、我国中学教学教师队伍存在的问题以及解决这些问题的思路三个方面阐述了笔者对这一问题的思考。     

学校网络德育的研究与实践初探

对学校网络环境下的德育教育的意义、方式方法从理论和实践两方面进行了探究．提出了加强网络德育工作的许多积极的意见和建议。     

语文网络教学案例分析和启示

通过语文教学中运用网络的案例分析，证明了网络教学是有利于激发学生学习兴趣，有利于分层教学的实施，有利于构建平等的师生关系和高效轻负的教学模式。     

美育·和谐·发展"以美育人"教学模式的设计与实施

“以美育人”教学模式,是为了达成我校“以美育人”教育模式中提出的教育理念和教育目标,以“整体优化、渗透美育”为原则来调控教学变量的一种教学组合方式,经过了七年的艰苦探索,“以美育人”教学模式在推进我校素质教育中发挥了重大作用。以下是我们设计和实施这一教学模式的一些做法和体会。一、“以美育人”教学模式的设计(一)背景我校的教育改革大体经历了三个阶段:1990年9月至1994年7月是营造“艺术教育特色”阶段,这一阶段的探索使我校摘掉了“薄弱学校”的帽子;之后转入第二阶段,着手构建“审美教育模式”;自1998年至今是第三阶段,…     

Do all roads really lead to Rome? The case of spelling acquisition

The French orthographic code is complex, and its acquisition is laborious (Catach, 2008; Fayol & Jaffré, 2008). Three hypotheses attempt to explain orthographic knowledge acquisition (OKA). For some, exposure to the code leads to OKA through a self-learning process (Share, 2004). For others, OKA benefits from graphophonological processes (Coltheart, Rastle, Perry, Langdon, & Ziegler, 2001). Finally, some authors suggest that OKA is possible thanks to visual specific processes (Ans, Carbonnel, & Valdois, 1998). The main goal of this study was to test these hypotheses in a classroom context with comparable samples. In total, 143 2nd-grade children participated in this quasi-experimental study with a pretest, immediate posttest, and delayed posttest design. We assigned participants to one of four conditions. For three conditions, we created three teaching procedures based on each of the hypotheses: frequency of contacts with target words; explicit teaching of graphophonological properties of words; explicit teaching of visual properties of words. The fourth served as a control group. ANOVA analyses indicated that all three experimental conditions favored OKA, showing that the different teaching procedures led to spelling development. However, the visual condition was the most favorable. Three main conclusions can be drawn from this study: (a) models of OKA should account for the different paths that can lead to spelling acquisition; (b) visual properties of words and their acquisition need additional research, and (c) applied research in real classroom contexts is not only relevant for informing teaching practices but also for better understanding how learning takes place.

     

Using combinations of video,audio and print to teach French at a distance: A case study of the formative evaluation cycle

The materials, procedures and findings of an evaluation of initial approaches to the use of audio visual media in a course teaching the French language to distance learners are reported as a case study of a formative evaluation. The study illustrates the design-research-revision stages of the formative evaluation cycle. Innovative features of the course were the pivotal role played by audiovisual (videocassette and audiocassette) media in providing resource material for teaching and learning, the use of short sequences for intensive study and the high degree of integration between the audiovisual media and the print. Key teaching design features of the draft audiovisual and print packages were identified and evaluated in terms of students’ reactions to them. Central issues of teaching design are discussed in relation to revisions made to the course materials in the light of the evaluation.     

中年自损话防范

中年人处于成果最多阶级,是事业的黄金时期。也是机体由盛转衰时期。为了使他们能发挥更大的作用,做好中年的自损保健预防工作,是我国当前一项非常重要的有现实意义的工作。     

Learning Is Moving in New Ways: The Ecological Dynamics of Mathematics Education

Whereas emerging technologies, such as touchscreen tablets, are bringing sensorimotor interaction back into mathematics learning activities, existing educational theory is not geared to inform or analyze passages from action to concept. We present case studies of tutor–student behaviors in an embodied-interaction learning environment, the Mathematical Imagery Trainer. Drawing on ecological dynamics—a blend of dynamical-systems theory and ecological psychology—we explain and demonstrate that: (a) students develop sensorimotor schemes as solutions to interaction problems; (b) each scheme is oriented on an attentional anchor—a real or imagined object, area, or other aspect or behavior of the perceptual manifold that emerges to facilitate motor-action coordination; and (c) when symbolic artifacts are introduced into the arena, they may both mediate new affordances for students’ motor-action control and shift their discourse into explicit mathematical re-visualization of the environment. Symbolic artifacts are ontological hybrids evolving from things with which you act to things with which you think. Students engaged in embodied-interaction learning activities are first attracted to symbolic artifacts as prehensible environmental features optimizing their grip on the world, yet in the course of enacting the improved control routines, the artifacts become frames of reference for establishing and articulating quantitative systems known as mathematical reasoning.     

巧用Powerpoint 2002新增动画功能制作楞次定律演示课件

介绍了运用Powerpoint 2002制作楞次定律演示课件的过程和技巧。