195 research outputs found

    One- and Multi-dimensional CWENOZ Reconstructions for Implementing Boundary Conditions Without Ghost Cells

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    We address the issue of point value reconstructions from cell averages in the context of third-order finite volume schemes, focusing in particular on the cells close to the boundaries of the domain. In fact, most techniques in the literature rely on the creation of ghost cells outside the boundary and on some form of extrapolation from the inside that, taking into account the boundary conditions, fills the ghost cells with appropriate values, so that a standard reconstruction can be applied also in the boundary cells. In Naumann et al. (Appl. Math. Comput. 325: 252-270. https://doi.org110.1016/j.amc.2017.12.041, 2018), motivated by the difficulty of choosing appropriate boundary conditions at the internal nodes of a network, a different technique was explored that avoids the use of ghost cells, but instead employs for the boundary cells a different stencil, biased towards the interior of the domain. In this paper, extending that approach, which does not make use of ghost cells, we propose a more accurate reconstruction for the one-dimensional case and a two-dimensional one for Cartesian grids. In several numerical tests, we compare the novel reconstruction with the standard approach using ghost cells

    One- and multi-dimensional CWENOZ reconstructions for implementing boundary conditions without ghost cells

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    We address the issue of point value reconstructions from cell averages in the context of third order finite volume schemes, focusing in particular on the cells close to the boundaries of the domain. In fact, most techniques known in the literature rely on the creation of ghost cells outside the boundary and on some form of extrapolation from the inside that, taking into account the boundary conditions, fills the ghost cells with appropriate values, so that a standard reconstruction can be applied also in boundary cells. In (Naumann, Kolb, Semplice, 2018), motivated by the difficulty of choosing appropriate boundary conditions at the internal nodes of a network, a different technique was explored that avoids the use of ghost cells, but instead employs for the boundary cells a different stencil, biased towards the interior of the domain. In this paper, extending that approach, which does not make use of ghost cells, we propose a more accurate reconstruction for the one-dimensional case and a two-dimensional one for Cartesian grids. In several numerical tests we compare the novel reconstruction with the standard approach using ghost cells

    Between-group behaviour in health care: gaps, edges, boundaries, disconnections, weak ties, spaces and holes. A systematic review

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    <p>Abstract</p> <p>Background</p> <p>Gaps are typically regarded as a problem to be solved. People are stimulated to close or plug them. Researchers are moved to fill deficits in the literature in order to realise a more complete knowledge base, health authorities want to bridge policy-practice disconnections, managers to secure resources to remedy shortfalls between poor and idealised care, and clinicians to provide services to patients across the divides of organisational silos.</p> <p>Despite practical and policy work in many health systems to bridge gaps, it is valuable to study research examining them for the insights provided. Structural holes, spaces between social clusters and weak or absent ties represent fissures in networks, located in less densely populated parts of otherwise closely connected social structures. Such gaps are useful as they illustrate how communication potentially breaks down or interactivity fails. This paper discusses empirical and theoretical work on this phenomenon with the aim of analysing a specific exemplar, the structures of silos within health care organisations.</p> <p>Methods</p> <p>The research literature on social spaces, holes, gaps, boundaries and edges was searched systematically, and separated into health [n = 13] and non-health [n = 55] samples. The health literature was reviewed and synthesised in order to understand the circumstances between stakeholders and stakeholder groups that both provide threats to networked interactions and opportunities to strengthen the fabric of organisational and institutional inter-relationships.</p> <p>Results</p> <p>The research examples illuminate various network structure characteristics and group interactions. They explicate a range of opportunities for improved social and professional relations that understanding structural holes, social spaces and absent ties affords. A principal finding is that these kinds of gaps illustrate the conditions under which connections are strained or have been severed, where the limits of integration between groups occurs, the circumstances in which social spaces are or need to be negotiated and the way divides are bridged. The study's limitations are that it is bounded by the focus of attention and the search terms used and there is yet to be developed a probabilistic, predictive model for gaps and how to connect them.</p> <p>Conclusions</p> <p>Gaps offer insights into social structures, and how real world behaviours of participants in workplaces, organisations and institutions are fragile. The paper highlights the circumstances in which network disjunctures and group divides manifest. Knowledge of these phenomenon provides opportunities for working out ways to improve health sector organisational communications, knowledge transmission and relationships.</p

    Interaction between non-executive and executive directors in English National Health Service trust boards: an observational study

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    Research funded by Burdett FoundationBackground National Health Service (NHS) trusts, which provide the majority of hospital and community health services to the English NHS, are increasingly adopting a ‘public firm’ model with a board consisting of executive directors who are trust employees and external non-executives chosen for their experience in a range of areas such as finance, health care and management. In this paper we compare the non-executive directors’ roles and interests in, and contributions to, NHS trust boards’ governance activities with those of executive directors; and examine non-executive directors’ approach to their role in board meetings. Methods Non-participant observations of three successive trust board meetings in eight NHS trusts (primary care trusts, foundation trusts and self-governing (non-foundation) trusts) in England in 2008–9. The observational data were analysed inductively to yield categories of behaviour reflecting the perlocutionary types of intervention which non-executive directors made in trust meetings. Results The observational data revealed six main perlocutionary types of questioning tactic used by non-executive directors to executive directors: supportive; lesson-seeking; diagnostic; options assessment; strategy seeking; and requesting further work. Non-executive board members’ behaviours in holding the executive team to account at board meetings were variable. Non-executive directors were likely to contribute to finance-related discussions which suggests that they did see financial challenge as a key component of their role. Conclusions The pattern of behaviours was more indicative of an active, strategic approach to governance than of passive monitoring or ‘rubber-stamping’. Nevertheless, additional means of maintaining public accountability of NHS trusts may also be required

    The Italian Museo Nazionale dell’Antartide

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    These abstract proceedings were produced based on the program for the POLAR2018 SCAR/IASC Open Science Conference, updated until 25 May 2018

    A four-year, systems-wide intervention promoting interprofessional collaboration

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    Background: A four-year action research study was conducted across the Australian Capital Territory health system to strengthen interprofessional collaboration (IPC) through multiple intervention activities. Methods: We developed 272 substantial IPC intervention activities involving 2,407 face-to-face encounters with health system personnel. Staff attitudes toward IPC were surveyed yearly using Heinemann et al’s Attitudes toward Health Care Teams and Parsell and Bligh’s Readiness for Interprofessional Learning scales (RIPLS). At study’s end staff assessed whether project goals were achieved. Results: Of the improvement projects, 76 exhibited progress, and 57 made considerable gains in IPC. Educational workshops and feedback sessions were well received and stimulated interprofessional activities. Over time staff scores on Heinemann’s Quality of Interprofessional Care subscale did not change significantly and scores on the Doctor Centrality subscale increased, contrary to predictions. Scores on the RIPLS subscales of Teamwork & Collaboration and Professional Identity did not alter. On average for the assessment items 33% of staff agreed that goals had been achieved, 10% disagreed, and 57% checked ‘neutral’. There was most agreement that the study had resulted in increased sharing of knowledge between professions and improved quality of patient care, and least agreement that between-professional rivalries had lessened and communication and trust between professions improved. Conclusions: Our longitudinal interventional study of IPC involving multiple activities supporting increased IPC achieved many project-specific goals, but improvements in attitudes over time were not demonstrated and neutral assessments predominated, highlighting the difficulties faced by studies targeting change at the systems level and over extended periods

    Do sexist mothers change more diapers? Ambivalent sexism, maternal gatekeeping and the division of childcare

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    This study examined the role of ambivalent sexist ideologies in the division of childcare responsibilities. It proposed maternal gatekeeping as a mediator through which hostile sexist attitudes toward men and women facilitate gendered division of childcare. A sample of 207 mothers with at least one child aged 6 years or younger completed extensive questionnaires. As hypothesized, the mother’s hostile sexist attitudes toward men and women were positively related to maternal gatekeeping tendencies. Gatekeeping, in turn, was related to the mother’s greater time investment in childcare and greater share of childcare tasks relative to the father. Finally, hostile sexist attitudes toward men and women had an indirect effect on the mother’s hours of care and relative share of childcare tasks, mediated though maternal gatekeeping. The findings underscore the importance of investigating the mechanisms through which sexist ideologies are translated into daily behaviors that help maintain a gendered social structure. They may be utilized to inform parenting interventions aimed at increasing collaborative family work and fathers’ participation
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