Development and validation of a method to directly measure the cable force during the hammer throw

The development of cable force during hammer-throw turns is crucial to the throw distance. In this paper, we present a method that is capable of measuring cable force in real time and, as it does not interfere with technique, it is capable of providing immediate feedback to coaches and athletes during training. A strain gauge was mounted on the wires of three hammers to measure the tension in the wire and an elite male hammer thrower executed three throws with each hammer. The output from the gauges was recorded by a data logger positioned on the lower back of the thrower. The throws were captured by three high-speed video cameras and the three-dimensional position of the hammer's head was determined by digitizing the images manually. The five best throws were analysed. The force acting on the hammer's head was calculated from Newton's second law of motion and this was compared with the force measured via the strain gauge. Qualitatively the time dependence of the two forces was essentially the same, although the measured force showed more detail in the troughs of the force-time curves. Quantitatively the average difference between the measured and calculated forces over the five throws was 76 N, which corresponds to a difference of 3.8% for a cable force of 2000 N.     

Crossing the Divide: A Survey of the High School Activities That Best Prepared Students to Write in College

Learning is a concept that is routinely used in various educational settings, and the enhancement of learning is the primary goal of many, if not all, educators and administrators. People involved in education, however, may not necessarily have extensively explored this commonly cited notion, and some may not have subsequently realized the conceptual depth and variations that learning entails in developing classroom materials and practices. For example, learning may be domain specific, and may involve a wide variety of processes and expressions. Additionally, it is linked to an array of factors, including individual differences, such as temperament, and culturally relative dimensions, such as value priorities. This article discusses implications for classroom practices to facilitate educators’ application of this complex concept.     

The Differential Effects of Repeating Kindergarten

We use the Early Childhood Longitudinal Study to investigate national patterns addressing (a) who repeats kindergarten, and (b) the subsequent cognitive effects of this event. Using OLS regression techniques, we investigate 1st-time kindergartners who are promoted, 1st-time kindergartners who are retained, and children who are already repeating kindergarten. Boys, children from low socioeconomic backgrounds, and children who enter kindergarten younger than typical age standards are consistently at risk for repeating kindergarten, but racial/ethnic patterns differ across the 2 cohorts of kindergarten repeaters. Evidence suggests that repeating kindergarten rarely leads to cognitive benefits in literacy or mathematics performance. On average, kindergarten repeaters continue to perform below their peers in terms of literacy skills both at the end of kindergarten and at the end of first grade (effect size [ES] = ?0.20 and ?0.24, respectively). In mathematics, the performance differentials are smaller but remain statistically significant. Evidence suggests that these differences vary somewhat by children's background and the school setting. Most children appear to receive little or no cognitive benefit from repeating kindergarten, suggesting the need for a careful reconsideration of current retention practices.     

The Key to Developing America's Workforce

Central Community College (CCC; Columbus, Nebraska) has taken the lead in several business, industry, and educational collaborations, beginning locally, then expanding statewide. This article shares two models that other community colleges may wish to replicate. The first describes the development of a collaborative team. The second shows that, by using the collaborative team approach, community colleges can generate substantial increases in both funding and full-time equivalents (a basis for community college funding inNebraska)while serving business andindustry.For example, since June 1998 CCC has generated nearly $1.4 million for its business and industry training programs. As a result of collaboration among CCC, the Nebraska Community College System, government agencies, and business and industry, the Statewide Interactive Multimedia Training Library was established.     

A Radical Approach to the Administration of Education

The specialist schools programme is currently seen by policy makers as a way of transforming the comprehensive education system, and meeting the local needs of parents for diversity and excellence. Insofar as this policy has an evidence-base this has been provided by studies showing higher levels of attainment among existing specialist schools. This article shows that if these advantages occur then there is a danger that they do so at a cost in terms of inclusion. The existing specialist schools have also shown a greater tendency to take proportionately fewer children from poor families over time, especially where these schools are also their own admission authorities. If this trend continues it will exacerbate the pre-existing social and economic segregation in the education system. The article ends by considering some of the implications for school organisation.     

College Students’ Perceptions About the Plausibility of Human-Induced Climate Change

Overcoming students’ misconceptions may be a challenge when teaching about phenomena such as climate change. Students tend to cite short-term weather effects as evidence to support or refute long-term climate transformations, which displays a fundamental misunderstanding about weather and climate distinctions. Confusion about weather and climate may also reflect student misunderstanding about deep time, a concept that spans several scientific content areas. This study examines the relationships between students’ understanding of deep time and their understandings of the distinctions between weather and climate, as well as how these understandings influence students’ perceptions about the plausibility of human-induced global climate change. Undergraduate students enrolled in an introductory science class on global climate change completed measures of their (a) understanding of distinctions between weather and climate, (b) knowledge of deep time, and (c) plausibility perceptions of human-induced climate change, both at the beginning and end of the course. The study includes comparison groups of similar students enrolled in introductory physical geography classes. Results revealed that greater knowledge of deep time and increased plausibility perceptions of human-induced climate change provide significant explanation of variance in students’ understanding of weather and climate distinctions. Furthermore, students achieve significantly increased understanding of weather and climate, even with brief instruction.