The effect of periodized resistance training on accelerative sprint performance

The purpose of this study was to assess the effect of periodized resistance training on accelerative sprint performance. Sixteen physically active men participated in a randomized controlled study. An experimental group (n = 10) completed an 8-week periodized resistance training intervention, while a control group (n = 6) did not train. Pre- and post-training measures of 20-m straight-line sprint time, including a 10-m split, maximum strength, and explosive strength, were recorded. Flight time, stance time, stride length, and stride frequency were quantified from digitized video recordings of the first three strides of the 20-m sprint. Resistance training resulted in significant increases in maximum strength (parallel back squat: 19%) and explosive strength (6-10%). However, both groups increased 0-10 m sprint times (experimental group = 6%; control group = 3%) while 10-20m times were reduced (experimental group = 7%; control group = 4%), highlighting the mechanical differences between the distinct sprint phases. The change during the 0-10m interval was accompanied by a reduction in stride frequency during the first three strides. Strength coaches should be aware that the potential benefits of increased muscular strength during short sprints are likely to be affected by mechanical specificity and that improvements in sprinting performance may not occur immediately after a period of resistance training.     

Extreme Programming: The Student View

Students in two offerings of a software engineering course were asked to write opinion papers regarding the use of Extreme Programming (XP) in an undergraduate computer science curriculum. The majority opposed the use of XP as the preferred life-cycle model for the project in that course, but they did support introducing some of the practices of XP in selected courses. They felt that unit testing and coding standards should become part of the introductory programming courses, but other practices should be deferred to specific project-oriented courses, or not introduced at all. Two pilot studies provided additional insights that are consistent with the students' opinions.     

Two- and Three-Year Achievement Results From the Memphis Restructuring Initiative

The purpose of this study was to analyze student achievement data from the first 3 years of the Memphis Restructuring Initiative (MRI). The MRI represents one of the first efforts by an urban school district to move past traditional top-down versus bottom-up reform debates by providing systemic support for outside-in/inside-out implementation and local co-construction of externally-developed reform designs in schools. Analyses of academic achievement focus on a state-of-the-art measure of value added assessments. At the end of 3 years the reforming schools had produced generally positive gains relative to locally matched control schools. Those results varied somewhat by reform type and by level of poverty in the communities being served. Based on the research methods used and the results, implications for future research and practice in educational reform are discussed.     

Small Robot Projects: Before You Start

Working with robots is an attractive possibility for educators at many levels. The price and availability of robotic hardware are favorable, there are often examples in the media of school groups doing robotic projects, and the projects support group design and co-operative activity. Still, these projects cannot be organized without considerable effort. In this article, we look at some of the opportunities and pitfalls that are encountered when working with robots in an educational setting, illustrating them with anecdotes from our experience with eight small robot-building projects, with participants ranging in age from nine to adult, and duration ranging from a single day to a full semester. We suggest some of the benefits of these projects and outline the problems organizers and participants will be likely to face.     

Technique and timing in women's inward two and one half somersault tuck (405C) and the men's inward two and one half somersault pike (405B) 3 m springboard dives

The purpose of this study was to compare the inward two and one half somersault dive in a tuck position (405C) performed by females (n = 22) and the inward two and one half somersault dive in a pike position (405B) performed by males (n = 24) to determine changes required by females to successfully perform 405B. Key performance variables in inward dives were also compared to those of backward dives. Video data of the dives performed at the 1999 FINA World Diving Cup were captured and digitized to obtain times and postures of the divers at specific events including takeoff and entry. Estimates of flight height and mass-normalised work done on the springboard were obtained from flight times. Some females worked the springboard strongly enough to generate sufficient height and rotation to perform 405B. Males performed 405B comfortably because they achieved better height and rotation than the females. A comparison of backward and inward dives revealed that divers are able to attain greater height in backward dives than inward dives.     

Les graphes de flux dans l'enseignement secondaire

Sans résuméTravail effectué dans le cadre du groupe de recherche en didactique de la mathématique du Conseil National des Recherches.     

John A. Stormer and the Hofstadter hypothesis

Does political rhetoric hold the key to an understanding of political pathology? Blending historical scholarship and behavioral research, this study tested empirically hypotheses derived from Richard Hofstadter's model of the “paranoid style” in American politics. The data were drawn from John A. Stormer's None Dare Call It Treason.