Analysis of repeated high-intensity running performance in professional soccer

The aims of this study were twofold: (1) to characterize repeated high-intensity movement activity profiles of a professional soccer team in official match-play; and (2) to inform and verify the construct validity of tests commonly used to determine repeated-sprint ability in soccer by investigating the relationship between the results from a test of repeated-sprint ability and repeated high-intensity performance in competition. High-intensity running performance (movement at velocities >19.8 km · h(-1) for a minimum of 1 s duration) was measured in 20 players using computerized time-motion analysis. Performance in 80 French League 1 matches was analysed. In addition, 12 of the 20 players performed a repeated-sprint test on a non-motorized treadmill consisting of six consecutive 6 s sprints separated by 20 s passive recovery intervals. In all players, most consecutive high-intensity actions in competition were performed after recovery durations ≥61 s, recovery activity separating these efforts was generally active in nature with the major part of this spent walking, and players performed 1.1 ± 1.1 repeated high-intensity bouts (a minimum of three consecutive high-intensity bouts with a mean recovery time ≤20 s separating efforts) per game. Players reporting lowest performance decrements in the repeated-sprint ability test performed more high-intensity actions interspersed by short recovery times (≤20 s, P < 0.01 and ≤30 s, P < 0.05) compared with those with higher decrements. Across positional roles, central-midfielders performed more high-intensity actions separated by short recovery times (≤20 s) and spent a larger proportion of time running at higher intensities during recovery periods, while fullbacks performed the most repeated high-intensity bouts (statistical differences across positional roles from P < 0.05 to P < 0.001). These findings have implications for repeated high-intensity testing and physical conditioning regimens.     

Do important inventions benefit from knowledge originating in other technological domains?

A frequently made claim in the innovation literature is that important inventions involve the transfer of new knowledge from one technological domain to another. This study uses U.S. patents granted from 1976 to 2006 to identify the role of knowledge acquired from outside each patent's technological domain. Our results do not seem to support the claim above. Increasing citations to external prior art is a significantly less important predictor of forward citation frequency than citing prior art that is technologically closer. This result is robust across several model specifications and ways of defining whether each flow of knowledge is external. The result is even stronger in the most highly cited technology categories. We discuss possible explanations for this apparently negative impact of external knowledge—including both measurement issues and challenges associated with assimilating disparate knowledge.     

Developing an instrument to characterise peer‐led groups in collaborative learning environments: assessing problem‐solving approach and group interaction

Collaborative learning is being used extensively by educators at all levels. Peer‐led team learning in a version of collaborative learning that has shown consistent success in science, technology, engineering and mathematics disciplines. Using a multi‐phase research study we describe the development of an observation instrument that can be used to assess peer‐led group learning. This paper illustrates the development of a classification system for peer‐led learning groups and an instrument based on this classification system. The instrument evaluates small learning groups on two important aspects of group learning: problem solving approach and group interaction style. We provide evidence of the factor structure of the two dimensions using both exploratory and confirmatory factor analysis. We also provide information about the reliability of the two scales as measured by the Cronbach's alpha coefficient. Data from a large peer‐led learning programme was used to conduct the factor analysis. Results from the factor analysis confirmed that the instrument is actually measuring two key characteristics of small learning groups: problem solving approach and group interaction style, characteristics that have been linked to effective functioning of the group and to the student learning outcomes. This instrument may be particularly appealing to practitioners (faculty members, those running small‐group learning programmes, etc.) because it is easy to use and it does not require extensive time for analysis.     

Exploring how relevance instructions affect personal reading intentions,reading goals and text processing: A mixed methods study

The purpose of this mixed methods study was to investigate how relevance instructions influence readers’ personal reading intentions, reading goals, text processing, and memory for text. Undergraduates (n = 52) were randomly assigned to one of three pre-reading relevance instruction conditions that asked them to read from a perspective or to read for understanding. Experimental results showed that information was read slower and remembered better when it was relevant. However, some readers spent more time reading irrelevant information, whereas others spent less time reading this information. Post-reading interviews were analyzed to explain these reading time differences. The interview data indicated that relevance instructions influenced readers’ goals and the strategies they used to meet those goals. The data sets were complementary: the quantitative data indicated differences in reading time and recall, and the qualitative data allowed us to explain why these differences occurred. These data revealed three distinct reader profiles within and across conditions, and demonstrate how relevance instructions affect reader goals, processing, and comprehension.     

Examining the Effects of High School Contexts on Postsecondary Enrollment

The present study is organized around the central hypothesis that the high school context affects students’ postsecondary outcomes. Drawing on a nationally representative sample of high school seniors from the Educational Longitudinal Survey (ELS:2002), this study broadens our empirical understanding of how students’ acquisition of human, social, and cultural capital at the individual and school level affects 2- and 4-year college attendance. Results highlight the normative role of high schools in promoting college enrollment, particularly the role of socioeconomics, academic preparation, and access to parent, peer, and college-linking networks. This study advances our understanding of the secondary-postsecondary nexus and has implications for policies and practices aimed at realizing the current administration’s promise of providing greater access to postsecondary education for all students.     

Using a Conceptual Understanding and Procedural Fluency Heuristic to Target Math Interventions with Students in Early Elementary

The study examined the use of a conceptual and procedural framework for identifying math deficits and delivering appropriate interventions. Participants were two first‐grade students and one third‐grade student, who were identified as struggling with the grade‐appropriate content in math. The first‐grade students focused on addition and the third‐grade student focused on multiplication. Each student's conceptual understanding was assessed, and students who lacked conceptual understanding received an intervention that addressed underlying concepts. Students with acceptable understanding of the underlying concepts received an intervention that focused on the procedure. The study used a single‐case, multiple‐baseline design, but the contra‐indicated intervention was administered for the first 2 weeks following baseline, with the prescribed intervention for the final 2 weeks. Each student showed more growth during the prescribed intervention phase when compared to the contra‐indicated phase.     

Angle-specific impairment of elbow flexors strength after isometric exercise at long muscle length

In this study, we examined the long-term reductions in maximal isometric force (MIF) caused by a protocol of repeated maximal isometric contractions at long muscle length. Furthermore, we wished to ascertain whether the reductions in MIF are dependent on muscle length--that is, are the reductions in MIF more pronounced when the muscle contracts at a short length. The MIF of the elbow flexors of seven young male volunteers was measured at five different elbow angles between 50 degrees and 160 degrees. On a separate day, the participants performed 50 maximal voluntary isometric muscle contractions with the elbow flexors at a lengthened position; that is, with the shoulder hyperextended at 45 degrees and the elbow joint fixed at 140 degrees. Following this exercise, the MIF at the five elbow angles, range of motion, muscle soreness and plasma creatine kinase activity were measured at 24 h intervals for 4 days. On day 1, the decline in MIF was higher at the more acute elbow angles of 50 degrees (42 +/- 8%) and 70 degrees (39 +/- 8%; both P<0.01) than at 90 degrees (26 +/- 4%) and 140 degrees (16 +/- 3%; both P<0.01). No significant reduction in MIF was evident at an elbow angle of 160 degrees. Maximal isometric force at an elbow angle of 140 degrees was fully restored on day 3, whereas at an angle of 50 degrees it remained depressed for the 4 day observation period. Restoration of MIF was a function of the elbow angle, with force recovery being less at the smaller angles. The range of motion was decreased by 14 +/- 2 degrees on day 1 (P<0.01) and did not return to baseline values by day 4. Muscle soreness ratings remained significantly elevated for the 4 day period. Serum creatine kinase peaked on day 1 (522 +/- 129 IU, P<0.01) and decreased thereafter. We conclude that the disproportionate decrease in MIF at the small elbow angles and the length-specific recovery in MIF after repeated maximal isometric contractions at long muscle length may be explained by the presence of overstretched sarcomeres that increased in series compliance of the muscle, therefore causing a rightward shift of the force-length relationship.     

The sound of music: Constructing science as sociocultural practices through oral and written discourse

In this article, we examine the oral and written discourse processes in a high school physics class and how these discourse processes are related to sociocultural practices in scientific communities. Our theoretical framework is based on sociological and anthropological studies of scientific communities and ethnographies of classroom life. We review the use of discourse analysis as a methodological orientation in science education and provide a logic‐of‐inquiry framing how we used discourse analysis in our ethnographic research. Our ethnographic analysis showed that, through students' participation in creating scientific papers on the physics of sound, their appropriation of scientific discourse was related to the framing activities of the teachers and the social practices established over time in the classroom. Our textual analysis of the student papers focused on how they used evidence to make claims. We explore the lessons learned from participating in the classroom of these students. © 1999 John Wiley & Sons, Inc. J Res Sci Teach 36: 883–915, 1999