On the internal structure of Guinier-Preston zones in Al-3 at.% Ag

High-angle annular dark-field scanning transmission electron microscopy has been employed to study partially decomposed Al-3 at.% Ag. After solutionizing at 550°C and quenching to room temperature, samples of an Al-3 at.% Ag single crystal were aged for short times at 105, 140 and 180°C. Independent of the ageing temperature for these early stages, Guinier-Preston zones with a diameter of about 3 nm are found. Most of these zones consist of a silver-depleted core surrounded by a silver-rich shell. The shell structure is not uniformly pronounced. Irregularly shaped Guinier-Preston zones are common, but the shell structure dominates. No indication of different structures of the Guinier-Preston zones in Al-3 at.% Ag was found after short ageing at the three different temperatures. The shell model for Guinier-Preston zones in aluminium-rich Al-Ag alloys, which was previously proposed on the basis of X-ray and neutron scattering experiments, is thus appropriate to describe the structure of the Guinier-Preston zones in the early stages of the decomposition.     

Qualitative elicitation of affective beliefs related to physical activity

ObjectivesBased on previous research that has identified affective attitude as a distinct predictor of physical activity (PA) behavior, the purpose of this pilot study was to elicit affective beliefs toward physical activity using qualitative data generated through specific open-ended questions.MethodsA sample of 126 undergraduate students participated in this study. Four open-ended questions based on the theory of planned behavior were posed to elicit affective beliefs. A content analysis was used to categorize and code data by theme based on common responses that emerged in the elicitation. A frequency count of the responses falling into each category was then conducted to establish which affective beliefs were the most common. The themes were established by two researchers and reviewed for internal homogeneity and external heterogeneity by a third party.ResultsThe results highlight key beliefs related to affective attitude. In descending rank order; Social Involvement, Pleasant Body States, Esteem, Improved Psychological Outcome, and General Enjoyment were the most common affective beliefs for PA involvement. Feelings arising from Time Issues/Conflict, Physical Unpleasantness, PA Environment, and Necessity/Obligation were the most common negative affective beliefs.ConclusionsThe results suggest that promoting enjoyment rather than necessity of PA and encouraging variety in PA may be effective. Addressing the importance of aesthetically pleasing environments and highlighting social interaction as a strategy rather than merely a norm or a form of support in behavioral research may be important.     

Theoretical underpinnings of a need-supportive intervention to address sustained healthy lifestyle changes in overweight and obese adolescents

ObjectivesRecent figures indicate that nearly a quarter of Australian adolescents are overweight or obese. Despite the well-established role of physical activity and healthy eating in reducing prevalence of obesity, there remains a lack of effective interventions that promote sustained behavior engagement. This paper aims to describe the theory-based integration and implementation of self-determination theory and goal setting theory in a family-based lifestyle intervention. Although these theories have been shown to independently predict motivation for behavior, a limited number of studies have described behavior-change techniques at a level to allow for effective evaluation and replication, and no studies have combined the theories in a healthy lifestyle behavior intervention.MethodsBehavior change techniques and the associated change mediators are described in relation to need-supportive environments provided by instructors and extended to parents in the home environment. Methods for motivating and promoting sustained engagement in adolescent physical activity and healthy eating and parent behaviors to support these lifestyle changes are discussed within the context of need-satisfaction and goal setting.ConclusionsThis study will contribute to understanding processes for developing and implementing behavior-change techniques based on the integration of two theories of motivation. Future interventions aimed at promoting maintenance of physical activity and healthy eating behaviors in overweight and obese adolescents will benefit by being informed of which techniques are effective at enhancing motivation within the intervention context and home environment.     

The immediate and sustained effects of acute exercise on planning aspect of executive function

ObjectiveThe purpose of this study was to clarify the immediate and sustained effects of an acute bout of exercise on the planning aspects of executive function.DesignThis study used a 2 × 4 true experimental design.MethodForty participants were randomly assigned to either the exercise or control groups and completed the Tower of London task prior to, immediately following, 30 min after, and 60 min after cessation of a 30 min, moderate intensity cycling exercise.ResultsAcute exercise positively impacted the total move score, which reflects planning efficiency, immediately after the cessation of exercise. Acute exercise also led to longer total initiation times, which were linked to better response inhibition of planning at 30 and 60 min after the cessation of exercise.ConclusionAcute exercise benefits planning, and the types of planning and the time points at which they were assessed modulate the relationship between acute exercise and executive function. Exercise-induced physiological and biological fluctuations have been proposed to explain the effects present immediately after exercise, and the mechanisms of such effects warrant further exploration.     

The effect of video observation on warmth and competence ratings of individuals with a disability

ObjectivesThis study examined whether a video featuring an adult with a physical disability engaging in either sport, exercise, or an activity of daily living (ADL) can mitigate negative stereotypes of disability held by people without a disability.DesignThis study used a pre-post design, involving three participant groups.MethodsParticipants (n = 212) read a vignette describing an adult with a disability (target). Consistent with the stereotype content model, participants judged the target's warmth and competence. One week later, participants viewed a video of the target participating in sport, exercise, or an ADL and judged the target's warmth and competence.ResultsJudgements of competence but not warmth changed over time. The greatest increases occurred in the sport condition. At follow-up, the typical high warmth low competence stereotype of disability was reversed; the character was judged as being more competent than warm especially in the sport condition.ConclusionVideos of adults with a disability engaging in physical activity, particularly sport, have potential to mitigate negative stereotypes of disability.     

Of particles and fields

In The Cosmic Blueprint,1 1 Paul Davies, The Cosmic Blueprint (Philadelphia: Templeton Foundation Press, 2004). View all notes Paul Davies takes note of the unresolved philosophical issues involved in the use of “field” imagery within evolutionary biology and quantum physics. The author proposes that the metaphysical scheme of Alfred North Whitehead with its notion of “actual occasions” might be key to solving these mysteries, but only if Whiteheadian “societies” were reinterpreted as enduring structured fields of activity for the ongoing succession of their constituent actual occasions. For, implicit in this revised understanding of Whiteheadian societies is a new paradigm for the philosophical relation between the One and the Many, which would allow for genuine top-down as well as bottom-up causation in the emergence of new forms or structures within the evolutionary process.     

The Effect of Prolonged Implementation of Cooperative Learning on Social Support Within the Classroom

This study was conducted to determine whether cooperative learning experiences are related to social support in the classroom. The relationship between cooperative learning and social support, the impact of prolonged implementation of cooperative learning on social support, and the effect of different frequency of cooperative learning experiences on social support in the classroom were investigated. An instrument measuring social support was administered in November and in January to 91 eighth-grade students from a suburban school district in the Midwest. The results indicate that cooperative learning was highly related to social support within the classroom and that the longer and more frequently students engaged in cooperative learning, the greater the social support within the classroom.     

Mentalizing skills of non-native,early signers: A longitudinal perspective

Using a population-based sample consisting of 401 6- to 12-year-olds, this study examined normative age and sex distributions on motor activity as measured in an actigraphic-based motion tracking system (MTS) and on attention-related functions derived from a Continuous Performance Test (CPT). Specific objectives were to present new knowledge on age-related change in motor activity and to study age effects on changes in motor activity and CPT performance as a function of time on task. Further, continuous relations between the two ADHD symptom domains and CPT performance and motor activity, and importantly, age effects in these relations were examined. CPT performance improved, and level of motor activity decreased with age. Linear associations between the two ADHD symptom domains and several of the CPT and MTS parameters support available research describing the nature of ADHD as a continuous dimension with variable expression throughout the general population. Further, our study is one of the first to provide developmental data using a time on task design, particularly with regard to motor activity. Imperative for ADHD future research are our results showing that age matters in the relation between ADHD behaviours and neuropsychological function.     

Gender dimorphic effects of voluntary running in laboratory rats depends on maturational status

This study examined the effect of 24 hr per day wheel access on running, body weight, and food intake for 30- or 50-day-old male and female rats under ad lib feeding conditions. Food intake and body weight were also monitored in a control group housed without access to running wheels. A dimorphic effect was observed after wheel introduction in 50-day-old but not 30-day-old rats: A temporary decline in food intake and a lasting decrease in body weight occurred for active male rats in comparison to their sedentary controls, and wheel access facilitated food intake and preserved body weight gain in female rats in comparison to their sedentary counterparts. Hyperphagia in adult females is interpreted in terms of the evolutionary acquired advantage linked to their reproductive function.     

Klaus B: The success story of an entrepreneur - a case study

Interorganizational teams are rapidly becoming more prevalent as a means to improve organizations' responsiveness. To achieve their objective, interorganizational teams must engage in extensive amounts of boundary spanning activity. This study juxtaposed three structural variables, namely team informational diversity, team boundedness, and extrateam links, in an integrated model aimed at promoting our understanding of how to increase interorganizational team boundary spanning activity and its effectiveness. The model was tested with 49 health promotion teams. Our findings indicated that three types of boundary spanning—scouting, ambassadorial, and coordinating—were positively associated with interorganizational team effectiveness. In addition, for team informational diversity, team boundedness, and extrateam links, scouting and ambassadorial activities fully mediated their relationships with team effectiveness; for team boundedness, coordinating activity also fully mediated its relationship with team effectiveness. These findings highlight the importance of incorporating structural considerations into the management of interorganizational teams.