Trial-by-trial analysis or averaging: implications for electromyographic models of rapid limb control     

Sherwood DE  Enebo BA 《Research quarterly for exercise and sport》2007,78(4):307-317

The control of human limb movement has been the focus of research for more than a century. A major issue to emerge from this work is the manner in which the central nervous system regulates electromyographic (EMG) activity to produce movements that differ in distance, velocity, and movement time. However the different methods of analysis often used to analyze EMG data could result in different kinematic-EMG relationships. In this study, participants performed an elbow flexion task to one of five distance goals (between 5 degrees and 50 degrees) using three movement speeds. EMG data from the right elbow flexors were compared using a trial-by-trial analysis and one based on averaged data. Averaging across trials underestimated biceps EMG amplitude at all movement distances and speeds compared to a trial-by-trial analysis. Averaging overestimated EMG burst duration compared to the trial-by-trial analysis. Peak agonist EMG amplitude was positively related to distance and inversely related to movement time. Agonist EMG duration was constant for movement distances less than 30 degrees but increased in the 50 degrees condition. The results support the view that peak EMG amplitude and duration can be controlled independently, but EMG duration changes only for longer distance movements when additional force is required.  相似文献   

A prototype Semantic Web-based digital content exchange for schools in Singapore     

Paul Shabajee  Brian McBride  Damian Steer  Dave Reynolds 《British journal of educational technology : journal of the Council for Educational Technology》2006,37(3):461-477

Singapore has many large and educationally valuable digital collections and is planning the development of many more. These digital collections contain historical, cultural and scientific multimedia objects, along with learning objects. At present, school teachers and pupils find it hard to locate many of these resources using traditional search engines. This paper describes a research investigation into the design and subsequent development of a prototype digital resource discovery portal (Digital Content Exchange) based on Semantic Web technologies, and explores some of the educational issues raised. The research project explored how the features of the Semantic Web might offer valuable additional educational benefits and affordances beyond that of those based on existing information retrieval technologies.  相似文献   

研究表明：视频游戏提高视力     

贾庆文 《海外英语》2009,(6):51-51

[1]视频游戏玩家或许会从消灭坏人的游戏中得到意想不到的好处——好的视力。玩“动作类”视频游戏会提高视觉能力，这对于像阅读和晚上驾驶汽车这样的任务来说至关重要，一项新的研究表明。  相似文献   

Ricochet: Confessions of a Gun Lobbyist by Richard Feldman     

Brian Anse Patrick 《Journal of American culture (Malden, Mass. : 2003)》2008,31(1):117-118

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Determinants of expected vs. actual match outcome: an examination of the German Bundesliga     

Tassilo von Hanau  Brian Philip Soebbing 《Soccer & Society》2015,16(1):63-75

Within society, there are many publications regarding expectations of firm performance. These include analysis, industry insiders and ranking service. Within sports, bookmakers provide betting odds that reflect the expected outcome of matches and are determined by several factors. The purpose of this study is to analyse the determinants of expected match outcome (i.e. betting odds) and compare them to those of actual match outcome. Data from the 2010/2011 season of the German Bundesliga (soccer) are made available that are combined with betting odds for each match. Regression results show that several factors, such as difference in standing between team and opponent, difference in competitions played, difference in points earned over the last five matches, differences in standing last season and home advantage significantly influence expected match outcome. On the contrary, actual match outcome is only determined by the latter two factors.  相似文献   

“Ah,I know why…”: children developing understandings through engaging with a picture book          下载免费PDF全文

Christine Braid  Brian Finch 《Literacy》2015,49(3):115-122

This article describes part of a study that explored the responses of nine‐ and ten‐year‐old children during a picturebook read aloud in a small group setting in a New Zealand classroom. The read aloud was interactive, where the participants were encouraged to respond to the book and to each other throughout the session. The authors created a framework for analysing the responses, adapting the model of Lawrence Sipe (2008) with its five categories of literary understanding, by expanding on the analytical category to enable a finer analysis of the responses. This article discusses the children's depth of thinking and the understandings they developed as they engaged with the read aloud. It also describes how the adapted framework allowed a closer analysis of these understandings, including the way the elements of art used in the illustrations contributed to the children's ideas. The findings suggest ways picturebooks can be used to promote children's thinking and how teachers can guide discussion about a complex text. Implications for use of the framework in further research are discussed.  相似文献   

The Grass Isn’t Always Greener: Perceptions of and Performance on Open-Note Exams     

Brian K. Sato  Wenliang He  Mark Warschauer  Pavan Kadandale 《CBE life sciences education》2015,14(2)

Undergraduate biology education is often viewed as being focused on memorization rather than development of students’ critical-thinking abilities. We speculated that open-note testing would be an easily implemented change that would emphasize higher-order thinking. As open-note testing is not commonly used in the biological sciences and the literature on its effects in biology education is sparse, we performed a comprehensive analysis of this intervention on a primary literature–based exam across three large-enrollment laboratory courses. Although students believed open-note testing would impact exam scores, we found no effect on performance, either overall or on questions of nearly all Bloom’s levels. Open-note testing also produced no advantage when examined under a variety of parameters, including research experience, grade point average, course grade, prior exposure to primary literature–focused laboratory courses, or gender. Interestingly, we did observe small differences in open- and closed-note exam performance and perception for students who experienced open-note exams for an entire quarter. This implies that student preparation or in-test behavior can be altered by exposure to open-note testing conditions in a single course and that ­increased experience may be necessary to truly understand the impact of this intervention.  相似文献   

Adolescents and Movie Ratings: Is Psychological Reactance a Theoretical Explanation for the Forbidden Fruit Effect?     

Kira A. Varava  Brian L. Quick 《广播与电子媒介杂志》2015,59(1):149-168

Adolescents were recruited to participate in an experiment to assess whether psychological reactance can provide a theoretical explanation for the forbidden fruit effect in the context of movie rating restrictions. In addition to examining if movie ratings served as antecedents to freedom threat perceptions, we investigated the role authoritarian parents had on freedom threat perception and reactance arousal. Results indicated that a movie with an NC-17 rating was perceived as a stronger freedom threat than R and PG-13 rated movies. Interestingly, adolescents who perceived their parents to be authoritarian were less likely to view movie ratings as a freedom threat. As expected, freedom threat perceptions were positively associated with psychological reactance. Reactance, in turn, was positively associated with both first and third person attitudes. The results are discussed with an emphasis on the theoretical and practical implications of the findings.  相似文献   

Hybrid Journals: Ensuring Systematic and Standard Discoverability of the Latest Open Access Articles     

Santiago Chumbe  Brian Kelly  Roddy MacLeod 《期刊图书馆员》2015,68(1-4):143-155

An important current challenge for research information providers is ensuring the automated discovery of Open Access (OA) content in hybrid journals. We found no evidence of discovery services that are able to systematically identify the crucially important free full-text availability of OA articles regardless of where and how such articles have been published (i.e., in fully OA journals or in hybrid journals). A solution is important because hybrid journals are proliferating and consequently the chances of missing OA articles is real and is happening. Nearly all of the major publishers now provide such journals in order to take advantage of recent changes in research funder requirements, and to be competitive in the new OA business model. By working with a group of scholarly publisher partners and by using standard metadata elements that publishers are already familiar with, we show a systematic and standardized manner to identify OA at the article level. Our proposal is to embed OA-related elements in the metadata freely exposed by publishers for aggregators and discovery services. For example, in the Table of Content (TOC) Really Simple Syndication feeds the publishers use to announce new journal issues and content. Based on the initial results obtained, we discuss the capabilities of our solution, and evaluate the impact produced by our application in the systematic discoverability of OA content from the participating hybrid journals, using an implementation done with the freely available journal current awareness service—JournalTOCs.  相似文献   

Pacing profiles and pack running at the IAAF World Half Marathon Championships     

Brian Hanley 《Journal of sports sciences》2015,33(11):1189-1195

The aim of this study was to describe the pacing profiles and packing behaviour of athletes competing in the IAAF World Half Marathon Championships. Finishing and split times were collated for 491 men and 347 women across six championships. The mean speeds for each intermediate 5 km and end 1.1 km segments were calculated, and athletes grouped according to finishing time. The best men and women largely maintained their split speeds between 5 km and 15 km, whereas slower athletes had decreased speeds from 5 km onwards. Athletes were also classified by the type of packing behaviour in which they engaged. Those who ran in packs throughout the race had smaller decreases in pace than those who did not, or who managed to do so only to 5 km. While some athletes’ reduced speeds from 15 to 20 km might have been caused by fatigue, it was also possibly a tactic to aid a fast finish that was particularly beneficial to medallists. Those athletes who ran with the same competitors throughout sped up most during the finish. Athletes are advised to identify rivals likely to have similar abilities and ambitions and run with them as part of their pre-race strategy.  相似文献