Physical Activity Levels and Prompts in Young Children at Recess: A Two-Year Study of a Bi-Ethnic Sample

Abstract

We investigated physical activity and encouragement for activity in a bi-ethnic cohort during recess. Activity and associated interactions of 287 children were recorded at preschool and again 2.2 years later. Children expended nearly twice as much energy at preschool recess than at elementary recess. Activity levels declined as recess time elapsed. At preschool, European-American children engaged in more moderate to vigorous activity than Mexican-Americans. As participants moved to elementary school, teachers' prompts to be active decreased and prompts from peers increased. Boys and girls received similar amounts of activity prompts at preschool, but prompts to boys increased over time. The findings suggest that school environments could be altered to promote healthful physical activity among young children.     

Chlordiazepoxide and the determinants of negative contrast

Previous experiments have shown that the negative contrast effect in consummatory behavior that occurs when rats are shifted from 32% to 4% sucrose is alleviated by the tranquilizer chlordiazepoxide (CDP). However, in these experiments, CDP was effective on the second postshift day but not on the first postshift day. The three experiments described in this paper suggest that this differential effectiveness of CDP is not due to the difference in preshift-postshift retention intervals on Day 1 (24 h) and Day 2 (48 h), but is due instead to the necessity of some degree of experience (about 5 min) with the postshift solution. These results, combined with those of an earlier study which showed elevated corticosterone in shifted animals on the second postshift day but not on the first postshift day, suggest that negative contrast may be a dynamic process, involving sequential processes of detection, evaluation, and conflict over the postshift period. It was further suggested that CDP becomes effective in moderating contrast only when the conflict stage is reached.     

Blaise CORTEX: A microprocessor system for libraries

In keeping with its role to provide information and cataloguing support services to the library and information world, the British Library is aware of the need to respond to its users' requirements by using the latest technology available. Since the development of intelligent terminals their application has been widespread in the community. The British Library has developed and adapted a commercially available intelligent terminal for specialist use within the library and information world, whilst at the same time retaining the terminal's own multi-faceted capabilities.     

Feeding the information eaters: Suggestions for integrating pure and applied research on language comprehension

This paper examines the current relation between pure and applied research on the comprehension of written information. It finds few points of contact. The suggestion is put forward that greater interaction could be mutually profitable. An information flow among researchers is proposed that starts with applied solutions to practical problems, continues through pure explanations of why these solutions are successful, and so enables the refinement of the original applied solutions. Because such an information flow begins with applied solutions, some of the problems of systematizing the findings of applied research are discussed. There can never be an applied theory of communication that specifies precisely how to design written information. Therefore a proposal is put forward for applying quality-control procedures to the preparation of documents. Such procedures indicate that several different kinds of research are necessary for determining the content, optimising the format and evaluating the effectiveness of written communications. The desirability of interactions among those who carry out these different kinds of research is discussed. Finally, the criteria for evaluating research in general are considered. The categorisation of particular studies as either useful or useless is found to be inappropriate.Thanks are due to Drs John Morton and John Marshall both for providing the incentive to put these thoughts in writing and for their advice and encouragement during the preparation of the paper. Many helpful comments on an earlier draft were received from Dr Arnold Wilkins, Dr James Hartley and Michael Macdonald-Ross. These were all much appreciated, even though some may appear not to have been implemented directly.