Numerical simulation of supernova-relevant laser-driven hydro experiments on OMEGA

In ongoing experiments performed on the OMEGA laser [J. M. Soures et al., Phys. Plasmas 5, 2108 (1996)] at the University of Rochester Laboratory for Laser Energetics, nanosecond laser pulses are used to drive strong blast waves into two-layer targets. Perturbations on the interface between the two materials are unstable to the Richtmyer–Meshkov instability as a result of shock transit and the Rayleigh–Taylor instability during the deceleration-phase behind the shock front. These experiments are designed to produce a strongly shocked interface whose evolution is a scaled version of the unstable hydrogen–helium interface in core-collapse supernovae such as SN 1987A. The ultimate goal of this research is to develop an understanding of the effect of hydrodynamic instabilities and the resulting transition to turbulence on supernovae observables that remain as yet unexplained. The authors are, at present, particularly interested in the development of the Rayleigh–Taylor instability through the late nonlinear stage, the transition to turbulence, and the subsequent transport of material within the turbulent region. In this paper, the results of numerical simulations of two-dimensional (2D) single and multimode experiments are presented. These simulations are run using the 2D Arbitrary Lagrangian Eulerian radiation hydrodynamics code CALE [R. T. Barton, Numerical Astrophysics (Jones and Bartlett, Boston, 1985)]. The simulation results are shown to compare well with experimental radiography. A buoyancy-drag model captures the behavior of the single-mode interface, but gives only partial agreement in the multimode cases. The Richtmyer–Meshkov and target decompression contributions to the perturbation growth are both estimated and shown to be significant. Significant dependence of the simulation results on the material equation of state is demonstrated, and the prospect of continuing the experiments to conclusively demonstrate the transition to turbulence is discussed. © 2004 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/71253/2/PHPAEN-11-7-3631-1.pd

Impurity-induced stabilization of solitons in arrays of parametrically driven nonlinear oscillators

Chains of parametrically driven, damped pendula are known to support soliton-like clusters of in-phase motion which become unstable and seed spatiotemporal chaos for sufficiently large driving amplitudes. We show that the pinning of the soliton on a "long" impurity (a longer pendulum) expands dramatically its stability region whereas "short" defects simply repel solitons producing effective partition of the chain. We also show that defects may spontaneously nucleate solitons.Comment: 4 pages in RevTeX; 7 figures in ps forma

Roadmaps to Utopia: Tales of the Smart City

Notions of the Smart City are pervasive in urban development discourses. Various frameworks for the development of smart cities, often conceptualized as roadmaps, make a number of implicit claims about how smart city projects proceed but the legitimacy of those claims is unclear. This paper begins to address this gap in knowledge. We explore the development of a smart transport application, MotionMap, in the context of a £16M smart city programme taking place in Milton Keynes, UK. We examine how the idealized smart city narrative was locally inflected, and discuss the differences between the narrative and the processes and outcomes observed in Milton Keynes. The research shows that the vision of data-driven efficiency outlined in the roadmaps is not universally compelling, and that different approaches to the sensing and optimization of urban flows have potential for empowering or disempowering different actors. Roadmaps tend to emphasize the importance of delivering quick practical results. However, the benefits observed in Milton Keynes did not come from quick technical fixes but from a smart city narrative that reinforced existing city branding, mobilizing a growing network of actors towards the development of a smart region. Further research is needed to investigate this and other smart city developments, the significance of different smart city narratives, and how power relationships are reinforced and constructed through them

Travelling solitons in the parametrically driven nonlinear Schroedinger equation

We show that the parametrically driven nonlinear Schroedinger equation has wide classes of travelling soliton solutions, some of which are stable. For small driving strengths nonpropogating and moving solitons co-exist while strongly forced solitons can only be stably when moving sufficiently fast.Comment: The paper is available as the JINR preprint E17-2000-147(Dubna, Russia) and the preprint of the Max-Planck Institute for the Complex Systems mpipks/0009011, Dresden, Germany. It was submitted to Physical Review

We are all one together : peer educators\u27 views about falls prevention education for community-dwelling older adults - a qualitative study

Background: Falls are common in older people. Despite strong evidence for effective falls prevention strategies, there appears to be limited translation of these strategies from research to clinical practice. Use of peers in delivering falls prevention education messages has been proposed to improve uptake of falls prevention strategies and facilitate translation to practice. Volunteer peer educators often deliver educational presentations on falls prevention to community-dwelling older adults. However, research evaluating the effectiveness of peer-led education approaches in falls prevention has been limited and no known study has evaluated such a program from the perspective of peer educators involved in delivering the message. The purpose of this study was to explore peer educators’ perspective about their role in delivering peer-led falls prevention education for community-dwelling older adults. Methods: A two-stage qualitative inductive constant comparative design was used.In stage one (core component) focus group interviews involving a total of eleven participants were conducted. During stage two (supplementary component) semi-structured interviews with two participants were conducted. Data were analysed thematically by two researchers independently. Key themes were identified and findings were displayed in a conceptual framework. Results: Peer educators were motivated to deliver educational presentations and importantly, to reach an optimal peer connection with their audience. Key themes identified included both personal and organisational factors that impact on educators’ capacity to facilitate their peers’ engagement with the message. Personal factors that facilitated message delivery and engagement included peer-to-peer connection and perceived credibility, while barriers included a reluctance to accept the message that they were at risk of falling by some members in the audience. Organisational factors, including ongoing training for peer educators and formative feedback following presentations, were perceived as essential because they affect successful message delivery. Conclusions: Peer educators have the potential to effectively deliver falls prevention education to older adults and influence acceptance of the message as they possess the peer-to-peer connection that facilitates optimal engagement. There is a need to consider incorporating learnings from this research into a formal large scale evaluation of the effectiveness of the peer education approach in reducing falls in older adults

Understanding innovators' experiences of barriers and facilitators in implementation and diffusion of healthcare service innovations: A qualitative study

This article is made available through the Brunel Open Access Publishing Fund - Copyright @ 2011 Barnett et al.Background: Healthcare service innovations are considered to play a pivotal role in improving organisational efficiency and responding effectively to healthcare needs. Nevertheless, healthcare organisations encounter major difficulties in sustaining and diffusing innovations, especially those which concern the organisation and delivery of healthcare services. The purpose of the present study was to explore how healthcare innovators of process-based initiatives perceived and made sense of factors that either facilitated or obstructed the innovation implementation and diffusion. Methods: A qualitative study was designed. Fifteen primary and secondary healthcare organisations in the UK, which had received health service awards for successfully generating and implementing service innovations, were studied. In-depth, semi structured interviews were conducted with the organisational representatives who conceived and led the development process. The data were recorded, transcribed and thematically analysed. Results: Four main themes were identified in the analysis of the data: the role of evidence, the function of inter-organisational partnerships, the influence of human-based resources, and the impact of contextual factors. "Hard" evidence operated as a proof of effectiveness, a means of dissemination and a pre-requisite for the initiation of innovation. Inter-organisational partnerships and people-based resources, such as champions, were considered an integral part of the process of developing, establishing and diffusing the innovations. Finally, contextual influences, both intra-organisational and extra-organisational were seen as critical in either impeding or facilitating innovators' efforts. Conclusions: A range of factors of different combinations and co-occurrence were pointed out by the innovators as they were reflecting on their experiences of implementing, stabilising and diffusing novel service initiatives. Even though the innovations studied were of various contents and originated from diverse organisational contexts, innovators' accounts converged to the significant role of the evidential base of success, the inter-personal and inter-organisational networks, and the inner and outer context. The innovators, operating themselves as important champions and being often willing to lead constructive efforts of implementation to different contexts, can contribute to the promulgation and spread of the novelties significantly.This research was supported financially by the Multidisciplinary Assessment of Technology Centre for Healthcare (MATCH)

The social context of tuberculosis treatment in urban risk groups in the United Kingdom: a qualitative interview study

Objectives: There is scant qualitative research into the experiences of tuberculosis treatment in urban risk groups with complex health and social needs in the UK. This study aimed to describe the social context of adherence to treatment in marginalised groups attending a major tuberculosis centre in London. Methods: Qualitative cross-sectional study using semi-structured interviews with patients receiving treatment for tuberculosis. Analytical frameworks aimed to reflect the role of broader social structures in shaping individual health actions. Results: Seventeen participants, the majority were homeless and had complex medical and social needs including, drug and alcohol use or immigration problems affecting entitlement to social welfare. Participants rarely actively chose not to take their medication but described a number of social and institutional barriers to adherence and their need for practical support. Many struggled with the physical aspects of taking medication and the side effects. Participants receiving DOT reported both positive and negative experiences reflecting type of DOT provider and culture of the organisation. Conclusions: There is a need for integrated care across drug, alcohol, HIV and homeless services in order to address complex clinical co-morbidities and social need which impact on patients’ ability to sustain a course of treatment

Predicting the outcome of conservative treatment with physiotherapy in adults with shoulder pain associated with partial-thickness rotator cuff tears – a prognostic model development study

Model coefficient statistics (DOCX 21 kb

PEARLS - A multicentre phase II/III trial of extended field radiotherapy for androgen sensitive prostate cancer patients with PSMA-avid pelvic and/or para-aortic lymph nodes at presentation.

PEARLS is a multi-stage randomised controlled trial for prostate cancer patients with pelvic and/or para-aortic PSMA-avid lymph node disease at presentation. The aim of the trial is to determine whether extending the radiotherapy field to cover the para-aortic lymph nodes (up to L1/L2 vertebral interspace) can improve outcomes for this patient group

The addition of a goal-based motivational interview to standardised treatment as usual to reduce dropouts in a service for patients with personality disorder: a feasibility study

<p>Abstract</p> <p>Background</p> <p>Rates of non-completion of treatments for personality disorder are high and there are indications that those who do not complete treatment have worse outcomes than those who do. Improving both cost-efficiency and client welfare require attention to engaging people with personality disorder in treatment. A motivational interview, based on the Personal Concerns Inventory, may have the ability to enhance engagement and retention in therapy. Here, we report the protocol for a feasibility study for a randomised controlled trial (RCT).</p> <p>Methods</p> <p>All referrals accepted to the psychological service of Nottinghamshire Healthcare NHS Trust's outpatient service for people with personality disorder are eligible for inclusion. Consenting participants are randomised to receive the Personal Concerns Inventory interview plus treatment as usual or treatment as usual only. We aim to recruit 100 participants over 11/2 years. A randomised controlled trial will be considered feasible if <abbrgrp><abbr bid="B1">1</abbr></abbrgrp> the recruitment rate to the project is 54% of all referrals (95% CI 54-64), <abbrgrp><abbr bid="B2">2</abbr></abbrgrp> 80% of clients find the intervention acceptable in terms of its practicability and usefulness (95% CI 80-91), and <abbrgrp><abbr bid="B3">3</abbr></abbrgrp> 80% of therapists report finding the intervention helpful (95% CI 80-100). In a full-scale randomised controlled trial, the primary outcome measure will be completion of treatment i.e., entry into and completion of ≥ 75% of sessions offered. Therefore, information will be collected on recruitment rates, attendance at therapy sessions, and completion of treatment. The feasibility of examining the processes of engagement will be tested by assessing the value, coherence, and attainability of goals pre-treatment, and engagement in treatment. The costs associated with the intervention will be calculated, and the feasibility of calculating the cost-benefits of the intervention will be tested. The views of clients and therapists on the intervention, collected using semi-structured interviews, will be analysed using thematic analysis.</p> <p>Discussion</p> <p>The Personal Concerns Interview as a preparation for treatment of people with personality has the potential to maximise treatment uptake, reduce unfilled places in treatment programmes, and prevent group treatments faltering through non-attendance. Most importantly, it has the potential to improve patient outcomes, helping them to function better and reduce hospitalisation.</p> <p>Trial Registration</p> <p>ClinicalTrials.Gov.UK Identifier - NCT01132976</p