Effect of different loading conditions on running mechanics at different velocities     

Germán Carretero-Navarro  Doménico Cherubini  Wolfgang Taube 《European Journal of Sport Science》2019,19(5):595-602

Weighted vests are widely used to improve running economy and performance. However, it is not well-studied how running mechanics are adapted to counteract the higher peak vertical ground reaction forces (Fpeak) while running with such a device. Therefore, the present study aimed to investigate the effects of different loading conditions on running mechanics at different velocities. Thirteen subjects participated in two separate sessions one week apart. In the first session, maximal aerobic speed (MAS) was determined through a maximal incremental running test while in the second session, they were instructed to run during one minute under different loading (0%, +10% and +20% of body mass [BM]) and velocity (60%, 80% and 100% of MAS) conditions in a random order. Spatiotemporal data were recorded and then running mechanics modelled using the spring-mass model. The main results indicated that vertical and leg stiffness (Kvert and Kleg, respectively) were increased (P?P?>?.05) when load was changed. At the same time, alterations of the running kinematics were observed such as longer contact times, reduced flight times, stride frequencies and step lengths, as well as an increase of the centre of mass dynamics. Based on these results it is assumed that runners maintain a certain stiffness level for each velocity despite different loading conditions. As a consequence, Fpeak increases and this probably causes spatiotemporal adjustments in the movement kinematics.  相似文献   

Culturally Sustaining Pedagogy Extended: Ethnic Pedagogies     

Barbara Laster  Rebecca Shargel  Marcia Watson-Vandiver 《Multicultural Perspectives》2020,22(2):91-100

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Quality flaw prediction in Spanish Wikipedia: A case of study with verifiability flaws     

Edgardo Ferretti  Leticia Cagnina  Viviana Paiz  Sebastián Delle Donne  Rodrigo Zacagnini  Marcelo Errecalde 《Information processing & management》2018,54(6):1169-1181

In this work, we present the first quality flaw prediction study for articles containing the two most frequent verifiability flaws in Spanish Wikipedia: articles which do not cite any references or sources at all (denominated Unreferenced) and articles that need additional citations for verification (so-called Refimprove). Based on the underlying characteristics of each flaw, different state-of-the-art approaches were evaluated. For articles not citing any references, a well-established rule-based approach was evaluated and interesting findings show that some of them suffer from Refimprove flaw instead. Likewise, for articles that need additional citations for verification, the well-known PU learning and one-class classification approaches were evaluated. Besides, new methods were compared and a new feature was also proposed to model this latter flaw. The results showed that new methods such as under-bagged decision trees with sum or majority voting rules, biased-SVM, and centroid-based balanced SVM, perform best in comparison with the ones previously published.  相似文献   

美国科技编辑概况     

Barbara Gastel  张忠丽 《科技与出版》2003,(4):58-61

在美国 ,科技编辑是一个逐渐被认可的领域。美国的科技编辑们在什么环境下工作 ?他们做什么 ?有什么样的教育背景 ?用什么样的体例手册和其他资源 ?有什么组织为他们服务 ?他们对哪些话题和事件有职业兴趣 ?文章描述了美国科技编辑的概况 ,着重说明上面这些问题。本文的写作在很大程度上依赖于我为科技编辑委员会的期刊《科技编辑》做编辑的经验。本文中 ,“科学”具有广泛的含义 ,包括医学及其相关领域。的确 ,在美国许多科技编辑是医学编辑。　　 工作环境和工作类型在美国 ,有各种各样的媒体雇佣科技编辑 ,这些媒体包括杂志、图书、大众…  相似文献   

Dealing with Difficult People in the Library.     

Barbara Bernoff Cavanaugh 《Journal of the Medical Library Association》2001,89(1):87

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Book reviews     

Ronald J. Zboray  Anita A. Jones  Shirley Kessel  Clarkson N. Potter  Megan Benton  William A. Wortman  Barbara Kiefer  Richard C. Rowson 《Publishing Research Quarterly》1992,8(4):86-106

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Introduction: Scientific and Technological Textbooks in the European Periphery     

José Ramón Bertomeu-sánchez  Antonio García-Belmar  Anders Lundgren  Manolis Patiniotis 《Science & Education》2006,15(7-8):657-665

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Ensuring Content‐Area Learning by Secondary Students with Learning Disabilities     

Donald D. Deshler  Jean B. Schumaker  B. Keith Lenz  Janis A. Bulgren  Michael F. Hock  Jim Knight  Barbara J. Ehren 《Learning disabilities research & practice》2001,16(2):96-108

Three factors tied with secondary student success in content‐area reading are demonstrated: (a) validated teacher‐focused and student‐focused interventions, (b) integrated and comprehensive service delivery systems, and (c) well‐designed, data‐based professional developmental programs. Difficult challenges face secondary students with LD and their teachers with regard to these students’ participation and success in required general education classes. Recently, instructional methods and materials have been developed and validated for promoting these students’ success. Some of them focus on how general education teachers plan and teach their content‐area courses; others focus on giving students the strategies they need to respond independently to the demands of their courses. This article describes these instructional methods, a service‐delivery model for implementing these interventions in secondary schools, and professional‐development mechanisms and administrative support that must be in place for the model to be maintained effectively.  相似文献   

The laser printer as an agent of change     

Barbara A. Brannon 《Publishing Research Quarterly》2002,17(4):3-8

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The View from Above: Map Reading Skills Project     

Derek Potgieter  Sandra Olën 《International Information and Library Review》1993,25(4)

In South Africa the education system for black children is fraught with problems. These problems are the direct result of apartheid and have been compounded by poverty and illiteracy. In this article the problem of poorly qualified or unqualified teachers is discussed especially with regard to the teaching of map skills to children in their fifth school year. The project team needed to develop affordable materials which could be used in large classes by teachers after a very short period of training. Books and other materials which are available commercially were examined, but for various reasons were found to be unsuitable for local conditions. After determining the extent of the problem, the project team followed a grassroots process of developing a flip chart which teachers learnt to use with confidence and which enabled pupils to master the concepts and skills necessary for understanding a map.  相似文献