Overweight and obesity affects more than 66% of the adult population and is associated with a variety of chronic diseases. Weight reduction reduces health risks associated with chronic diseases and is therefore encouraged by major health agencies. Guidelines of the National Heart, Lung, and Blood Institute (NHLBI) encourage a 10% reduction in weight, although considerable literature indicates reduction in health risk with 3% to 5% reduction in weight. Physical activity (PA) is recommended as a component of weight management for prevention of weight gain, for weight loss, and for prevention of weight regain after weight loss. In 2001, the American College of Sports Medicine (ACSM) published a Position Stand that recommended a minimum of 150 min wk(-1) of moderate-intensity PA for overweight and obese adults to improve health; however, 200-300 min wk(-1) was recommended for long-term weight loss. More recent evidence has supported this recommendation and has indicated more PA may be necessary to prevent weight regain after weight loss. To this end, we have reexamined the evidence from 1999 to determine whether there is a level at which PA is effective for prevention of weight gain, for weight loss, and prevention of weight regain. Evidence supports moderate-intensity PA between 150 and 250 min wk(-1) to be effective to prevent weight gain. Moderate-intensity PA between 150 and 250 min wk(-1) will provide only modest weight loss. Greater amounts of PA (>250 min wk(-1)) have been associated with clinically significant weight loss. Moderate-intensity PA between 150 and 250 min wk(-1) will improve weight loss in studies that use moderate diet restriction but not severe diet restriction. Cross-sectional and prospective studies indicate that after weight loss, weight maintenance is improved with PA >250 min wk(-1). However, no evidence from well-designed randomized controlled trials exists to judge the effectiveness of PA for prevention of weight regain after weight loss. Resistance training does not enhance weight loss but may increase fat-free mass and increase loss of fat mass and is associated with reductions in health risk. Existing evidence indicates that endurance PA or resistance training without weight loss improves health risk. There is inadequate evidence to determine whether PA prevents or attenuates detrimental changes in chronic disease risk during weight gain.

Objective-Physical Activity Across the Curriculum (PAAC) was a three-year cluster randomized controlled trial to promote physical activity and diminish increases in overweight and obesity in elementary school children.Methods-Twenty-four elementary schools were cluster randomized to the PAAC intervention or served as control. All children in grades two and three were followed to grades four and five. PAAC promoted 90 minutes/wk of moderate to vigorous intensity physically active academic lessons delivered by classroom teachers. BMI was the primary outcome, daily PA and academic achievement were secondary outcomes.Results-The three-year change in BMI for PAAC was 2.0 ± 1.9 and control 1.9 ± 1.9, respectively (NS). However, change in BMI from baseline to three years was significantly influenced by exposure

This study examines task-based, synchronous computer-mediated communication (CMC) among intermediate-level learners of English. The research specifically explores (a) whether learners engage in negotiated interaction when they encounter new lexical items, (b) whether task type has an effect on the amount of negotiation that transpires, and (c) how this computer-mediated negotiation compares to that noted in the face-to-face literature. Fourteen nonnative-nonnative dyads collaboratively completed 4 communicative tasks using ChatNet, a browser-based chat program. Each dyad completed 2 jigsaw and 2 decision-making tasks, which were each "seeded" with 8 target lexical items. The chatscripts reveal that learners do in fact negotiate for meaning in the CMC environment when nonunderstanding occurs. Furthermore, task type was found to have a definite influence on the extent to which learners engaged in negotiation, but not necessarily in the same way that has been observed in the face-to-face literature. Though the negotiation that occurs in the CMC environment proceeds in ways that are roughly similar to face-to-face negotiation, the observed differences call for a new model of computer-mediated negotiation. This new model is presented as a more accurate tool for describing computer-mediated negotiated interaction than those offered to chart face-to-face negotiation episodes.AS THE PROLIFERATION OF COMPUTERS IN the language learning classroom continues, it is important for language teachers embracing the use of computer technology to understand the norms of language use during computer-mediated interaction and their potential relationship to second language acquisition (SLA). The use of synchronous computer-mediated communication (CMC) in particular has recently increased in the communicative language classroom through freeware and readily-available Webbased "chat" programs such as AOL Instant Messenger and Yahoo Messenger, among countless others. In general, CMC appears to be a potentially useful tool for language teaching and learning as well as for research into both second language use and acquisition. Research suggests that CMC may elicit more (and more equitable) learner participation (that found in face-to-face interaction. Computermediated communication may also help create a less stressful environment for second language practice (Chun, 1998). Furthermore, because of the "logging" capabilities of most CMC programs, we may capture and readily access this interaction for both research and pedagogical purposes. Indeed, the computer as a data collection instrument seems to be less intrusive in many ways than traditional procedures for recording face-to-face student interaction.Though the use of well-crafted communicative activities, which promote learner-learner interaction, is generally considered sound pedagogical practice, the theoretical and empirical support for the efficacy of such activities for facilitating SLA is less than conclusive. Nevertheless, it is widely held that communicative interaction

This article offers a capacious view of technology to suggest broad principles relating technology and language use, language teaching, and language learning. The first part of the article considers some of the ways that technological media influence contexts and forms of expression and communication. In the second part, a set of heuristic questions is proposed to help guide language teachers and researchers in determining how to incorporate technology into their teaching practice or research agenda and evaluate its suitability and impact. These questions are based primarily on the goal of helping learners to pay critical attention to the culturally encoded connections among forms, contexts, meanings, and ideologies that they will encounter and produce in different mediums, both traditional and new.