Reliability and validity of the Yo-Yo intermittent recovery test level 1 in young soccer players

Abstract

The present study investigated the test-retest reliability from the Yo-Yo IR1 (distance and heart rate responses), and the ability of the Yo-Yo IR1 to differentiate between elite and non-elite youth soccer players. A total of 228 youth soccer players (11–17 years) participated: 78 non-elite players to examine the test-retest reliability within 1 week, added with 150 elite players to investigate the construct validity. The main finding was that the distance covered was adequately reproducible in the youngest age groups (U13 and U15) and highly reproducible in the oldest age group (U17). Also, the physiological responses were highly reproducible in all age groups. Moreover, the Yo-Yo IR1 test had a high-discriminative ability to distinguish between elite and non-elite young soccer players. Furthermore, age-related standards for the Yo-Yo IR1 established for elite and non-elite groups in this study may be used for comparison of other young soccer players.     

Weaving a New 'Net: A Mesh-Based Solution for Democratizing Networked Communications

Although the Internet is largely decentralized in its communication and social patterns, its technical and regulatory apparatuses are highly centralized and hierarchical. Consequently, digital communications are vulnerable to a degree of surveillance and censorship that would be unthinkable in traditional social arenas, threatening “Internet freedom” and cyberliberties in both democratic and politically repressed societies. We believe a new architecture is required in order to protect the continuance of civil liberties in networked society. In this article, we propose 10 “social specifications” describing the requirements of such a network, and outline an architecture called MondoNet that meets these specifications using ad hoc, wireless mesh networking technologies. We also address the legal and technical challenges facing the MondoNet project, and anticipate future developments in this field.     

A toy model that predicts the qualitative role of bar bend in a push jerk

In this work, we describe a simple coarse-grained model of a barbell that can be used to determine the qualitative role of bar bend during a jerk. In simulations of this model, we observed a narrow time window during which the lifter can leverage the elasticity of the bar in order to lift the weight to a maximal height. This time window shifted to later times as the weight was increased. In addition, we found that the optimal time to initiate the drive was strongly correlated with the time at which the bar had reached a maximum upward velocity after recoiling. By isolating the effect of the bar, we obtained a generalized strategy for lifting heavy weight in the jerk.     

Effects of psycholinguistic instruction on spelling performance

Two studies were conducted in which phonology‐based instructional strategies designed for improving spelling skills of elementary school children were compared against instruction strategies that relied only on visual exposure of words. The first study involved a total of 93 children. Of these, 46 were instructed by drawing their attention to the psycholinguistic nature of their spelling errors. The remaining 47 children in the comparison group were shown the correct version of all the words. In study II 15 children were placed in a treatment group and were taught phoneme awareness, and 15 children were placed in a comparison group and were exposed to printed words only. In both studies, posttests showed that children taught through psycholinguistic and phoneme awareness methods significantly outperformed the visual training groups. Further, these gains were retained after a period of 2 weeks. © 2001 John Wiley & Sons, Inc.     

Developmental dyslexia: Is it different from other forms of reading disability?

A controversy whether developmental dyslexia is qualitatively different from other forms of reading disability has existed among reading specialists for many years. In the present study, the hypothesis that the etiology of dyslexia is different from that of other forms of reading disability because of differences in the components that malfunction was tested. A number of studies have shown that the two components that contribute to a large proportion of variance in reading are decoding and comprehension. It is, therefore, possible that a breakdown of different components could lead to different forms of disabilities. College students who were poor readers were assigned to two groups on the basis of their IQ. Conforming to the traditional criterion of dyslexia, those who had an IQ of 95 and above were considered as dyslexic. Those who had an IQ of 85 or below were placed in the Nonspecific Reading-Disabled group. These two groups of poor readers and a group of normal readers were administered a large number of reading-related tests. It was found that the two reading-disabled groups differed from each other in six of the seven areas assessed. There was very little overlap of scores between the two groups in these areas. The results were interpreted to suggest that poor decoding skill is the etiology of developmental dyslexia and that it differs from other forms of reading disability which are caused by generalized cognitive deficits.     

An alternate route for preparing deaf children for BiBi programs: the home language as L1 and cued speech for conveying traditionally spoken languages

This article focuses on nonsigning hearing parents of deaf children who share the goals of bilingual-bicultural (BiBi) programs for their child, opt for their home language to be their deaf child's first language (L1), and have questions about communication options (e.g., oral methods, manually coded English [MCE] systems, or Cued Speech) for conveying that language. We present research findings related to the effectiveness of MCE systems and Cued Speech for conveying English and developing deaf children's reading abilities. We compare the cueing of English and the signing of MCE systems in terms of theoretical and practical advantages. Finally, we suggest research needs.     

Field-based professional development of teachers engaged in distance education: experiences from the Arctic

We examine the experiences of five teachers who traveled with a team of educators, scientists, and explorers on circumpolar Arctic expeditions to deliver adventure learning (AL) programs to K–12 students at a distance. Results highlight the personal and professional impacts this opportunity had on teachers, including their empowering, fulfilling, and mentally exhausting experiences while assisting in delivering distance education to students worldwide. The article concludes with a discussion of issues to consider in the development of similar programs.     

Using Food Science Demonstrations to Engage Students of All Ages in Science,Technology, Engineering,and Mathematics (STEM)

Abstract: The overarching goal of the Science, Technology, Engineering, and Mathematics (STEM) Education Initiative is to foster effective STEM teaching and learning throughout the educational system at the local, state, and national levels, thereby producing science literate citizens and a capable STEM workforce. To contribute to achieving this goal, we have assembled six food science demonstrations for use at all educational levels and have presented these lessons to students at the elementary through higher education levels. The focus of this article is to share these food science demonstrations and our experiences using them so that others can use them for engaging students in STEM disciplines, through food science, at any educational level. Featured demonstrations include: (1) liquid nitrogen ice cream: a matter of changing phases, (2) seeing our senses work together, (3) whipping up the cream, (4) milk versus dark: what is the difference?, (5) counting calories by burning them, and (6) culinary spherification: the wonders of cross‐linking. Overall, our experience with using these demonstrations has been very positive. Students appear engaged in the learning process and love to consume the demonstration end products. Downloadable handouts containing demonstration details for each demonstration are available as supporting information.     

Enhancing preschool children's vocabulary: Effects of teacher talk before,during and after shared reading

This observational study analyzed patterns of teacher extratextual talk as it occurs before, during, and after reading books to children, and the frequency and duration of teacher questioning by type (label, define, associate) on preschoolers’ receptive and expressive vocabulary knowledge. Over the course of 18 weeks, 13 teachers and 100 children participated in ninety 20-min small-group sessions of teacher-guided shared reading instruction. Teachers’ reading instruction was examined through videotaped observations using the Multi-Option Observation System for Experimental Studies (MOOSES™; Tapp, Wehby, & Ellis, 1995). Two findings, in particular, yielded relevant educational and theoretical implications. First, time spent after reading was significantly related to expressive vocabulary. However, question timing did not seem to matter in terms of receptive vocabulary outcomes. Second, duration of teacher association questioning was significantly related to receptive vocabulary outcomes while both frequency and duration of teacher vocabulary-related association-level questioning were related to expressive vocabulary. For receptive vocabulary, both vocabulary- and comprehension-related association-level questioning mattered. These findings complement the body of work demonstrating that engaging children in interactive shared reading that elicits their active participation is related to meaningful gains in children's language and literacy growth. Limitations of the study and directions for future research are discussed.