Does exercise motivation predict engagement in objectively assessed bouts of moderate-intensity exercise? A self-determination theory perspective

This study examined the utility of motivation as advanced by self-determination theory (Deci & Ryan, 2000) in predicting objectively assessed bouts of moderate intensity exercise behavior. Participants provided data pertaining to their exercise motivation. One week later, participants wore a combined accelerometer and heart rate monitor (Actiheart; Cambridge Neurotechnology Ltd) and 24-hr energy expenditure was estimated for 7 days. After controlling for gender and a combined marker of BMI and waist circumference, results showed autonomous motivation to positively predict moderate-intensity exercise bouts of >or=10 min, or=20 min, and an accumulation needed to meet public health recommendations for moderate intensity activity (i.e., ACSM/AHA guidelines). The present findings add bouts of objectively assessed exercise behavior to the growing body of literature that documents the adaptive consequences of engaging in exercise for autonomous reasons. Implications for practice and future work are discussed.     

Pedometer reliability, validity and daily activity targets among 10- to 15-year-old boys

The aims of this study were to: (1) determine whether the number of pedometer counts recorded by adolescents differs according to the adiposity of the participant or location on the body; (2) assess the accuracy and reliability of pedometers during field activity; and (3) set adolescent pedometer-based physical activity targets. Seventy-eight 11- to 15-year-old Boy Scouts completed three types of activity: walking, fast walking and running. Each type was performed twice. Participants wore three pedometers and one activity monitor during all activities. Participants were divided into groups of normal weight (BMI < 85th percentile) and at risk of being overweight (BMI > or = 85th percentile). Intra-class correlations across the three activities indicated reliability (r = 0.51 - 0.92, P < 0.001). This conclusion was supported by narrow limits of agreement that were within a pre-set range that was practically meaningful. Multivariate analysis of covariance indicated adiposity group differences, but this difference was a function of the increased stature among the larger participants (P < 0.001). Ordinary least-squares regression models and multi-level regression models showed positive associations between the number of pedometer and activity monitor counts recorded by the three groups of participants during all activities (all P < 0.001). The mean number of counts recorded for all participants during the fast walk was 127 counts per minute. In conclusion, the pedometers provided an accurate assessment of adolescent physical activity, and a conservative estimate of 8000 pedometer counts in 60 min is equivalent to 60 min of moderate to vigorous physical activity.     

On Linear Least-Squares Estimators for Continous-Time Stochastic Systems

The problem of least-squares state estimation of stochastic continuous-time linear systems is reconsidered. A concise derivation of the least-squares minimal-order estimator is presented using an innovations approach. An important result is the reinstatement of the problem in a least-squares estimation framework independent of deterministic observer theory. A second result is thus the clarification of previous approaches to the problem, particularly in relation to observer theory.     

Information Technology and the Emergent Organization

The potential impact of information technology on the workplace is greater than simply changing how work is performed by individuals. Our assumptions regarding information systems in traditional organizations are out of date and being challenged by the capabilities provided by new information technologies. The organization of the future will require a much higher degree of system integration in order to respond to the increasing demands for flexibility and rapid change in the global marketplace. This will require a complete re-thinking of current organizational assumptions and a whole system re-design effort at the organizational level. Performance technologists, in order to play a vital role in building this new organizational future, will need to apply their collective knowledge on the whole system rather than on isolated elements, and to understand the interaction between the technology and the organization.     

Laptops in the Scottish Primary School: Interim Report

Abstract

The following paper should be seen as an addition to that provided in the Proceedings of the 7th ICTE.’ For reasons of brevity, it does not deal to any large extent with the background to the project, but details the progress of a study into the effects of introducing laptops into primary (elementary) school. The project has provided every pupil in one class with a laptop computer and has tracked the use being made of it as a curriculum tool for writing. The second phase of the project is under way, with a completion date of April 1991.     

>How to avoid implying that physicalism is true: a problem for teachers of science

It is difficult to teach science without implying, in a broad sense, that physicalism is true. This is a problem for teachers, regardless of whether they accept or reject physicalism, as well as for students. Physicalism‐‐it used to be called materialism‐‐is not a single doctrine, but a family of doctrines. Six of these are described and it is argued that they are not logically favoured by science. Since alternative metaphysical schemes exist (e.g. Whitehead's) which are consistent with scientific facts, evidence which supports a scientific theory over rivals, even decisively, does not have the logical power to decide in favour of physicalism. Science teaching's insinuation of physicalism can be avoided by deliberately stressing such uncontroversial features of science as: the unfinished nature of research; the use of idealizations in scientific theories; how all scientific theories at best only approach the truth; and that older theories are now known to be, strictly, false, although they still fit the facts to some degree.