Exit problems associated with affine reflection groups

We obtain a formula for the distribution of the first exit time of Brownian motion from the alcove of an affine Weyl group. In most cases the formula is expressed compactly, in terms of Pfaffians. Expected exit times are derived in the type \~A case. The results extend to other Markov processes. We also give formulas for the real eigenfunctions of the Dirichlet and Neumann Laplacians on alcoves, observing that the `Hot Spots' conjecture of J. Rauch is true for alcoves.Comment: 34 pages. Rewritten in some places to improve presentation. To appear in Probability Theory and Related Field

edra 34: Bibliography of Books on Display

edra 34 | People Shaping Places | Minneapolis, MNhttps://digitalcommons.andrews.edu/edra-bibliographies/1018/thumbnail.jp

Massaging desire : disadvantaged students\u27 aspirations for higher education.

Australia is in a challenging position. Having ridden the resources boom up and down, it now finds it has fallen back from the OECD pack in terms of the number of young adults (25 to 34 year olds) with higher education qualifications. This, coupled with a change of government, has prompted transformation in the Australian higher education system that will increasingly require research and policy to address students’ aspirations for university. Aspiration has long been considered an important condition for entry to higher education (Anderson, Boven, Fensham & Powell, 1980). However, recent policy reforms, specifically the setting of targets for significant increases in participation, now demand a rethinking of the concept. Across Australian universities, the current attainment rate for bachelor degrees among 25 to 34 year olds is around 32 per cent, while over the past twenty years the enrolment rate of students from low socioeconomic status (SES) backgrounds has stagnated at around 15 per cent (Commonwealth of Australia, 2009). In response to the Bradley Review of Australian Higher Education in 2008, the Australian Government has set ‘20/40 targets’ in a bid to increase low SES enrolment to 20 per cent by 2020, and to increase to 40 per cent by 2025 the number of 25 to 34 year olds holding bachelor degrees. This will require that around 220,000 additional students attain bachelor degrees by 2025. Given current levels of unmet demand for university entry, this overall increase in participation, and the proportional increase of low SES students in particular, will only be achievable by engaging with populations of potential students who do not currently seek university places

Fermion Masses and Mixing in Four and More Dimensions

We give an overview of recent progress in the study of fermion mass and flavor mixing phenomena. Mass matrix ansatze are considered within the SM and SUSY GUTs where some predictive frameworks based on SU(5) and SO(10) are reviewed. We describe a variety of schemes to construct quark mass matrices in extra dimensions focusing on four major classes: models with the SM residing on 3-brane, models with universal extra dimensions, models with split fermions and models with warped extra dimensions. We outline how realistic patterns of quark mass matrices could be derived from orbifold models in heterotic superstring theory. Finally, we address the fermion mass problem in intersecting D-branes scenarios, and present models with D6-branes able to give a good quantitatively description of quark masses and mixing. The role of flavor/CP violation problem as a probe of new physics is emphasized.Comment: a review based on seminars presented by S.K. in different places, 34 pages, late

Structural fatigue in the 34-meter HA-Dec antennas

Structural modifications to the 34-m hour-angle-declination antennas, coupled with the use of the antennas beyond their intended lifespans, have led to structural fatigue, as evidenced by damage to the declination drive gear and cracks on the structural members and gussets. An analysis and simulation were made of the main antenna structural members. The analysis showed that the total stress to the antenna structure substantially exceeds the maximum levels recommended by the American Institute of Steel Construction (AISC). Although each of the separate static conditions of stress is only 50 percent of the total stress and does not reach the AISC reduced yield limit, fatigue can and did occur, causing the material to crack in the weakest places

Perceptions of healthy eating and physical activity in an ethnically diverse sample of young children and their parents: the DEAL prevention of obesity study

Background: Ethnicity is a consistent correlate of obesity; however, little is known about the perceptions and beliefs that may influence engagement with obesity prevention programmes among ethnic minority children. Barriers to (and facilitators of) healthy lifestyles were examined in the qualitative arm of the London (UK) DiEt and Active Living (DEAL) study. Methods: Children aged 8–13 years and their parents, from diverse ethnic groups, were recruited through schools and through places of worship. Thirteen focus group sessions were held with 70 children (n = 39 girls) and eight focus groups and five interviews with 43 parents (n = 34 mothers). Results: Across ethnic groups, dislike of school meals, lack of knowledge of physical activity guidelines for children and negativity towards physical education at school among girls, potentially hindered healthy living. Issues relating to families' wider neighbourhoods (e.g. fast food outlets; lack of safety) illustrated child and parental concerns that environments could thwart intentions for healthy eating and activity. By contrast, there was general awareness of key dietary messages and an emphasis on dietary variety and balance. For ethnic minorities, places of worship were key focal points for social support. Discourse around the retention of traditional practices, family roles and responsibilities, and religion highlighted both potential facilitators (e.g. the importance of family meals) and barriers (reliance on convenience stores for traditional foods). Socio-economic circumstances intersected with key themes, within and between ethnic groups. Conclusions: Several barriers to (and facilitators of) healthy lifestyles were common across ethnic groups. Diversity of cultural frameworks not only were more nuanced, but also shaped lifestyles for minority children.</p