509 research outputs found

    Steered Transition Path Sampling

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    We introduce a path sampling method for obtaining statistical properties of an arbitrary stochastic dynamics. The method works by decomposing a trajectory in time, estimating the probability of satisfying a progress constraint, modifying the dynamics based on that probability, and then reweighting to calculate averages. Because the progress constraint can be formulated in terms of occurrences of events within time intervals, the method is particularly well suited for controlling the sampling of currents of dynamic events. We demonstrate the method for calculating transition probabilities in barrier crossing problems and survival probabilities in strongly diffusive systems with absorbing states, which are difficult to treat by shooting. We discuss the relation of the algorithm to other methods.Comment: 11 pages, 8 figure

    Practical rare event sampling for extreme mesoscale weather

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    Extreme mesoscale weather, including tropical cyclones, squall lines, and floods, can be enormously damaging and yet challenging to simulate; hence, there is a pressing need for more efficient simulation strategies. Here we present a new rare event sampling algorithm called Quantile Diffusion Monte Carlo (Quantile DMC). Quantile DMC is a simple-to-use algorithm that can sample extreme tail behavior for a wide class of processes. We demonstrate the advantages of Quantile DMC compared to other sampling methods and discuss practical aspects of implementing Quantile DMC. To test the feasibility of Quantile DMC for extreme mesoscale weather, we sample extremely intense realizations of two historical tropical cyclones, 2010 Hurricane Earl and 2015 Hurricane Joaquin. Our results demonstrate Quantile DMC's potential to provide low-variance extreme weather statistics while highlighting the work that is necessary for Quantile DMC to attain greater efficiency in future applications.Comment: 18 pages, 9 figure

    Narratives that nudge: Raising theoretical questions about reflective practice

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    The narratives of pre-service teachers in this paper tell a story which interrupts the notion that reflective practice necessarily produces a transformative self. Although this argument is not new, the extent to which the utility of reflective practice is taken for granted in the current context of teacher education (beginning and continuing) remains greater than ever. We show how this normative construction of reflective practice and the understandings of self that it produces in the narratives of pre-service teachers are undermined in the context of schooling. We suggest that further research is needed in this area. Through this effort we raise questions about the spaces in which reflective practice is assumed to operate and the ways in which the reflective self it assumes has been disconnected from society and relations of power. We situate ourselves as teachers, teacher educators and researchers who desire theoretically informed positions from which we can begin to critically address, extend or displace our current understandings of these issues. This paper raises questions about reflective practice and its relationship to pedagogy within the current context of schooling

    Teachers' responses to the emotional needs of children and young people. Results from the Scottish Needs Assessment Programme

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    The Scottish Needs Assessment Programme (SNAP) was established in 2000 to advise the Scottish Government on the emotional health of the country's children and young people. The second phase, conducted in 2002-2003, involved surveying professionals who provide specialist mental health services to children and young people, and also those who work with children and young people in a variety of settings but whose training is not in mental health. Based on the survey, this paper outlines the emotional difficulties faced by children and young people in educational settings, and describes how teachers in particular are responding to these difficulties. It also discusses teachers' experiences of working with other professionals and agencies, in particular the frustrations they feel in their efforts to make suitable arrangements on behalf of young people

    Effectiveness of the Mindfulness in Schools Programme: non-randomised controlled feasibility study

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    Open Access Article. Copyright ©2013 The Royal College of PsychiatristsMindfulness-based approaches for adults are effective at enhancing mental health, but few controlled trials have evaluated their effectiveness among young people

    Inversion of Randomly Corrugated Surfaces Structure from Atom Scattering Data

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    The Sudden Approximation is applied to invert structural data on randomly corrugated surfaces from inert atom scattering intensities. Several expressions relating experimental observables to surface statistical features are derived. The results suggest that atom (and in particular He) scattering can be used profitably to study hitherto unexplored forms of complex surface disorder.Comment: 10 pages, no figures. Related papers available at http://neon.cchem.berkeley.edu/~dan

    A healthy start : promoting mental health and well-being in the early primary school years

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    This study was in part funded by the University of Malta.Mental health problems in children represent a significant international health concern, with up to one in five children using mental health services during the course of any given year. Identifying the processes of what prevents social, emotional and behaviour difficulties (SEBD) and promotes healthy development from an early age can make a significant contribution to the promotion of positive mental health in children. This article describes a longitudinal study which sought to identify the risk and promotive factors as young children move from the early to junior years in primary school. Multilevel analysis was used to identify the individual, classroom, school, home and community factors that predict change in SEBD and in prosocial behaviour in the early school years. It also calculated the cumulative effect of the various risk and promotive factors on the pupils’ well-being and mental health. The article presents the windows of vulnerability and opportunity for young children’s healthy development, proposing a trajectory for healthy development in early and middle childhood.peer-reviewe

    Use, acceptability and impact of booklets designed to support mental health self-management and help seeking in schools:Results of a large randomised controlled trial in England

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    Mental health booklets may provide a low-cost means of promoting mental health self-management and help seeking in schools. The aim of the study was to assess the (a) use, (b) acceptability and (c) impact of booklets for students in primary (10-11 years) and secondary school (12-13 years) alone and in conjunction with funding for targeted mental health support. This was a 2 × 2 factorial cluster randomized controlled trial, in which 846 schools in England were randomly allocated to receive/not receive: (1) booklets for students containing information on mental health self-management and help seeking, and (2) funding for mental health support as part of a national mental health initiative. 14,690 students (8139 primary, 6551 secondary) provided self-report on mental health, quality of life (baseline and 1 year follow-up) and help seeking (follow-up). (a) Approximately, 40 % primary school students and 20 % secondary school students reported seeing the booklets. (b) Of these, 87 % of primary school students reported that the booklet was 'very helpful' or 'quite helpful', compared with 73 % in secondary school. (c) There was no detectable impact of booklets on mental health, quality of life or help seeking, either alone or in conjunction with additional funding through the national mental health initiative. Lack of discernable impact of booklets underscores the need for caution in adopting such an approach. However, it is feasible that the impact was obscured by low uptake or that booklets may be more effective when used in a targeted way
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