Students Designing Video Games about Immunology: Insights for Science Learning

Exposing American K–12 students to science, technology, engineering, and math (STEM) content is a national initiative. Game Design Through Mentoring and Collaboration targets students from underserved communities and uses their interest in video games as a way to introduce science, technology, engineering, and math topics. This article describes a Game Design Through Mentoring and Collaboration summer program for 16 high school students and 3 college student mentors who collaborated with a science subject matter expert. After four weeks, most students produced 2-D video games with themes based on immunology concepts from the educational science game Immune Attack. Findings from three groups that finished their games and one group with an uncompleted game are explored.     

Weight,gravity and air pressure: Mental representations by Italian middle school pupils

The research reports an investigation concerned with schemes of commonsense knowledge connecting the three elements weight, air and gravity to the phenomenon of free fall. Inferences about the mental representations of Italian middle school pupils (12‐13 years of age) have been gathered by interviewing a sample of 40 children, using a number of different questions and searching for the possible consistencies among the whole set of answers. Three schemes are suggested: in the first, the force of gravity operating on the weight of the objects causes their fall; in the second, the force of gravity and weight are two independent causes for the fall of objects; and in the third the force of gravity, weight and the phenomenon of fall are unrelated entities. Air is implicitly or explicitly invoked as a cause of either weight or gravity, or both.     

The effect of video‐feedback on the learning of the tennis service by intermediate players

Effects of video‐feedback on improvement of the tennis service were investigated in subjects having at least 2 years of playing experience in tennis. The experiment was carried out in an indoor tennis hall under normal training conditions.

Subjects were randomly divided into three groups: a video‐feedback training (VFT) group, a traditional training (TT) group and a control group, each consisting of 22 subjects. While the subjects of the control group received no training at all, subjects in both the VFT and TT groups were trained twice weekly during 5 consecutive weeks. Each training session lasted 40 min, of which 30 min was spent on actual practice in training of the service. The remaining 10 min was spent on watching, analysing and discussing video recordings of either their own service performed during the training session (VFT group), or ground strokes and volleys of top level players (TT group). Both the VFT and TT group showed significantly greater improvements in both achievement scores and form (technique) scores than did the control group. No differences, however, could be demonstrated between the VFT and TT group, indicating that the subjects of the former group did not benefit from the video‐feedback they received.

While form scores correlated significantly (P < 0.001) with the velocity of the served ball, no such relation between form scores and spatial accuracy was apparent.     

Straight sprinting is the most frequent action in goal situations in professional football

Abstract

The present study aimed to analyse the influence of speed and power abilities in goal situations in professional football.

During the second half of the season 2007/08, videos of 360 goals in the first German national league were analysed by visual inspection. For the assisting and the scoring player the situations immediately preceding the goal were evaluated. The observed actions were categorised as: no powerful action, rotation (around the body's centre-line), straight sprint, change-in-direction sprint, jump, or a combination of those categories.

Two hundred and ninety-eight (83%) goals were preceded by at least one powerful action of the scoring or the assisting player. Most actions for the scoring player were straight sprints (n = 161, 45% of all analysed goals, P < 0.001) followed by jumps (n = 57, 16%), rotations and change-in-direction sprints (n = 22, 6% each). Most sprints were conducted without an opponent (n = 109, P < 0.001) and without the ball (n = 121, P < 0.001). Similarly, for the assisting player the most frequent action was a straight sprint (n = 137, P < 0.001) followed by rotations (n = 28), jumps (n = 22) and change-in-direction sprints (n = 18). The straight sprints were mostly conducted with the ball (n = 93, P = 0.003).

In conclusion, straight sprinting is the most frequent action in goal situations. Power and speed abilities are important within decisive situations in professional football and, thus, should be included in fitness testing and training.     

Using video simulations and virtual reality to improve decision-making skills in basketball

ABSTRACT

A large body of literature supports the effectiveness of using video simulations to improve decision-making skills in invasion sports. However, whether these improvements are transferable (from the laboratory to the court/field) and generalizable (from trained to untrained plays) remains unknown. In addition, it remains to be determined whether presenting the video simulations using virtual reality provides an added-value. To investigate these questions, varsity-level basketball players underwent four training sessions during which they observed video clips of basketball plays presented either on a computer screen (CS group) or using a virtual reality headset (VR group). A third group watched footage from NCAA playoff games on a computer screen (CTRL group). Decision-making was assessed on-court before and after the training sessions using two types of plays: “trained” plays (presented during the CS and VR training sessions) and “untrained” plays (presented only during the on-court tests). When facing the trained plays in the posttest, both VR and CS groups significantly outperformed the CTRL group. In contrast, when facing the untrained plays, the VR group outperformed both the CS and CTRL groups. Our results indicate that CS training leads to transferable but non-generalized decision-making gains while VR training leads to transferable and generalized gains.     

Comparison of Three Methods of Estimating Energy Expenditure: Caltrac,Heart Rate,and Video Analysis

Abstract

This study examined the accuracy of a new device (Caltrac) in estimating energy expenditure via acceleration measurements. Energy expenditure of 20 high school students during basketball class activity (average length = 37 min) was estimated using the Caltrac, heart rate recording, and video analysis. Heart rate recording and video analysis estimates of energy expenditure were determined from heart rate, caloric expenditure curves, and an activity rating scale, respectively. The following estimates of caloric expenditure (M ± SD) were found: heart rate recording = 196 ±73 > Caltrac = 163 ±49 > film analysis = 123 ± 30 kcal (p < .05). Laboratory simulations of the basketball activity revealed that the Caltrac energy expenditure was not significantly different from the actual energy expenditure (p > .05). The heart rate recording and video analysis estimates of energy expenditure were significantly (p < .05) higher and lower, respectively, than the actual energy expenditure. The Caltrac is a lightweight, low-cost device that provides a relatively accurate estimate of energy expenditure in free-ranging activities, such as basketball.     

The Visual Instruction System

Abstract

Three experimental groups of 45 S's each were given 30 repeated isometric wrist flexion trials. Each trial consisted of a maximal 5-sec. effort followed by a rest period of 5,10, or 20 sec. In each recuperation group S's were divided into subgroups representing high, middle, and low levels of absolute strength. The data were analyzed by an analysis of variance of trends allowing statistical tests for best fitting trend components and trend differences between subgroups. Low level of strength groups always demonstrated a fatigue pattern significantly different from high and middle levels. High and middle levels displayed similar patterns differing only on absolute level of strength. Caution isefore indicated in definition and magnitude assessment of derived curve components based upon composite fatigue curves secured on unknown levels of strength. It seems unlikely that the same factors responsible for muscular fatigue can be operating in the same manner at different levels of isometric strength.     

基于云视频构建智慧家庭多屏互动环境探索

随着三网融合产业的深入推进和视频产业的飞速发展,构建多屏互动应用环境对于建设智慧家庭、建设家庭视频娱乐体系有着重要的现实意义,同时也符合未来产业发展要求以及提高人们幸福指数的需要。结合最新的网络技术,对利用云计算技术实现视频的云存储构建智慧家庭多屏互动应用环境的定位、目标、实现模式,意义等进行初步探讨,并对未来进行展望。     

浅析移动视频监控技术在电力系统中的应用

随着通信技术的快速发展,如今已步入4G时代,3G网络更是得到了普遍应用.对于供电企业来说,基于3G与4G网络的移动视频监控技术,可以进一步提升电力系统的监控水平.本文从移动视频监控系统的应用现状与需求分析入手,着重介绍了新技术在移动监控平台如何实现,并利用现有视频监控平台,融入3G与4G网络,提出平台升级的可行性方案.     

无线Mesh网络路由与信道分配综述

移动互联网已成为二十一世纪信息技术领域的研究热点.高性能移动终端的快速更新及先进的无线网络接入技术,不但繁荣了全球移动互联网服务广度,而且提升了全球移动互联网的服务水平,体现了“无处不在的网络,无所不能的业务”.由于无线Mesh网络与传统的网络技术相比有诸多优点,使之成为当前无线网络接入技术的研究主流.本文首先简介了无线Mesh网络结构、特点、安全性.然后从路由与信道分配方面对无线Mesh网络研究现状进行综述.最后总结了无线Mesh网络所面临的挑战及未来的发展方向.