University of Victoria

About: University of Victoria is a education organization based out in Victoria, British Columbia, Canada. It is known for research contribution in the topics: Population & Galaxy. The organization has 14994 authors who have published 41051 publications receiving 1447972 citations. The organization is also known as: Victoria College.

Supermassive stars as a source of abundance anomalies of proton-capture elements in globular clusters

Abstract: We propose that the abundance anomalies of proton-capture elements in globular clusters, such as the C-N, Na-O, Mg-Al and Na-F anti-correlations, were produced by super-massive stars with M ~ 10,000 Msun. Such stars could form in the runaway collisions of massive stars that sank to the cluster center as a result of dynamical friction, or via the direct monolithic collapse of the low-metallicity gas cloud from which the cluster formed. To explain the observed abundance anomalies, we assume that the super-massive stars had lost significant parts of their initial masses when only a small mass fraction of hydrogen, Delta X ~ 0.15, was transformed into helium. We speculate that the required mass loss might be caused by the super-Eddington radiation continuum-driven stellar wind or by the diffusive mode of the Jeans instability.

Prevention in the first place: schools a setting for action on physical inactivity

Abstract: Promoting physical activity has become a priority because of its role in preventing childhood obesity and chronic disease. Ecological approaches that recognise the interaction between individuals and the settings in which they spend their time are currently at the forefront of public health action. Schools have been identified as a key setting for health promotion. An overview of the literature addressed the promotion of physical activity in schools and showed that school-based strategies (elementary or high school) that utilised classroom-based education only did not increase physical activity levels; one notable exception was screen time interventions. Although evidence is sparse, active school models and environmental strategies (interventions that change policy and practice) appear to promote physical activity in elementary schools effectively. There is also strong evidence to support multicomponent models in high schools, particularly models that incorporate a family and community component. An emerging trend is to involve youth in the development and implementation of interventions. In the context of childhood obesity and sedentary lifestyles, modest increases in physical activity levels in school-based trials are important. School initiatives must be supported and reinforced in other community settings. Health professionals play a key role as champions in the community, based on their influence and credibility. Health professionals can lend support to school-based efforts by asking about and emphasising the importance of physical activity with patients, encouraging family-based activities, supporting local schools to adopt an "active school" approach and advocating for support to sustain evidence-based and promising physical activity models within schools.

Adaptive response surface method - a global optimization scheme for approximation-based design problems

Abstract: For design problems involving computation-intensive analysis or simulation processes, approximation models are usually introduced to reduce computation lime. Most approximation-based optimization methods make step-by-step improvements to the approximation model by adjusting the limits of the design variables. In this work, a new approximation-based optimization method for computation-intensive design problems - the adaptive response surface method(ARSM), is presented. The ARSM creates quadratic approximation models for the computation-intensive design objective function in a gradually reduced design space. The ARSM was designed to avoid being trapped by local optima and to identify the global design optimum with a modest number of objective function evaluations. Extensive tests on the ARSM as a global optimization scheme using benchmark problems, as well as an industrial design application of the method, are presented. Advantages and limitations of the approach are also discussed