Variability and progression in competitive performance of Paralympic swimmers

Abstract

Analysis of variability and progression in performance of top athletes between competitions provides information about performance targets that is useful for athletes, practitioners, and researchers. In this study, 724 official finals times were analysed for 120 male and 122 female Paralympic swimmers in the 100-m freestyle event at 15 national and international competitions between 2004 and 2006. Separate analyses were performed for males and females in each of four Paralympic subgroups: S2–S4, S5–S7, S8–S10 (most through least physically impaired), and S11–S13 (most through least visually impaired). Mixed modelling of log-transformed times, with adjustment for mean competition times, was used to estimate variability and progression. Within-swimmer race-to-race variability, expressed as a coefficient of variation, ranged from 1.2% (male S5–S7) to 3.7% (male S2–S4). Swimming performance progressed by approximately 0.5% per year for males and females. Typical variation in mean performance time between competitions was ～1% after adjustment for the ability of the athletes in each competition, and the Paralympic Games was the fastest competition. Thus, taking into account variability, progression, and level of competition, Paralympic swimmers who want to increase substantially their medal prospects should aim for an annual improvement of at least 1–2%.     

Teaching a new science and technology course: A sociocultural perspective

This study inquires into the influence of subject communities on the practice of secondary school teachers as they teach a new science and technology course that crosses traditional subject and department boundaries. The study focuses on two teachers from different professional communities—a science teacher and a technology teacher—who were teaching an applied physics course that was piloted in British Columbia. Interview and observational data were collected that illuminate the classroom practices and perspectives of the two teachers. As the teachers taught the course, they both changed their normal teaching practice. Their respective new practices, however, were different in important ways even though they both started with the same course outline, textbooks, and laboratory materials. We interpret these differences in the teachers' practices using sociocultural practice theory and argue that the differences can be understood in terms of the influence of their different professional communities which are shown to provide the backdrops against which the teachers developed their approaches to the course. Recommendations are made that encourage using the subject community as a unit of analysis in educational change studies and using sociocultural practice theory as a theoretical perspective for thinking about educational change and making policy decisions. © 1998 John Wiley & Sons, Inc. J Res Sci Teach, 35: 777–789, 1998.     

Biochemical observations on certain insectivorous plants

The liquor from pitchers of Nepenthes, which were entirely free from insect captures, contained a protease which exerted its activity in a slightly acid medium. Catalase, urease, esterase, diastase, invertase, maltase, lactase, and emulsin were not present in the pitcher liquor.A substance, which reduced Benedict alkaline copper solution, was frequently, but not invariably, present in the pitcher liquor; it was probably sugar derived from the nectar.The pitcher liquor contained chlorides, and did not contain phosphates and saponins.A composite sample of the secretion of the leaves of Dionæa muscipula was examined, and was found to contain a protease which was active in the presence of 0.2 per cent. hydrochloric acid.The leaves of Dionæa miiscipula have been analyzed; and their composition is reported.The author is indebted to Dr. Walter Steckbeck for the photograph of Dioncæa muscipula and to Dr. John M. Macfarlane for those of Nepenthes.