335 research outputs found

    The Effects of Next-Nearest-Neighbor Interactions on the Orientation Dependence of Step Stiffness: Reconciling Theory with Experiment for Cu(001)

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    Within the solid-on-solid (SOS) approximation, we carry out a calculation of the orientational dependence of the step stiffness on a square lattice with nearest and next-nearest neighbor interactions. At low temperature our result reduces to a simple, transparent expression. The effect of the strongest trio (three-site, non pairwise) interaction can easily be incorporated by modifying the interpretation of the two pairwise energies. The work is motivated by a calculation based on nearest neighbors that underestimates the stiffness by a factor of 4 in directions away from close-packed directions, and a subsequent estimate of the stiffness in the two high-symmetry directions alone that suggested that inclusion of next-nearest-neighbor attractions could fully explain the discrepancy. As in these earlier papers, the discussion focuses on Cu(001).Comment: 8 pages, 3 figures, submitted to Phys. Rev.

    Non-universal equilibrium crystal shape results from sticky steps

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    The anisotropic surface free energy, Andreev surface free energy, and equilibrium crystal shape (ECS) z=z(x,y) are calculated numerically using a transfer matrix approach with the density matrix renormalization group (DMRG) method. The adopted surface model is a restricted solid-on-solid (RSOS) model with "sticky" steps, i.e., steps with a point-contact type attraction between them (p-RSOS model). By analyzing the results, we obtain a first-order shape transition on the ECS profile around the (111) facet; and on the curved surface near the (001) facet edge, we obtain shape exponents having values different from those of the universal Gruber-Mullins-Pokrovsky-Talapov (GMPT) class. In order to elucidate the origin of the non-universal shape exponents, we calculate the slope dependence of the mean step height of "step droplets" (bound states of steps) using the Monte Carlo method, where p=(dz/dx, dz/dy)$, and represents the thermal averag |p| dependence of , we derive a |p|-expanded expression for the non-universal surface free energy f_{eff}(p), which contains quadratic terms with respect to |p|. The first-order shape transition and the non-universal shape exponents obtained by the DMRG calculations are reproduced thermodynamically from the non-universal surface free energy f_{eff}(p).Comment: 31 pages, 21 figure

    A realist informed mixed-methods evaluation of Schwartz Center Rounds® in England

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    Background Schwartz Center Rounds® (Rounds) were introduced into the UK in 2009 to support health-care staff to deliver compassionate care, something the Francis report (Francis R. Report of the Mid Staffordshire NHS Foundation Trust Public Inquiry. London: The Stationery Office; 2013) identified as lacking. Rounds are organisation-wide forums that prompt reflection and discussion of the emotional, social and ethical challenges of health-care work, with the aim of improving staff well-being and patient care. Objectives How, in which contexts and for whom Rounds participation affects staff well-being at work, increases social support for staff and improves patient care. Design (1) A scoping review of Rounds literature and comparison with alternative interventions; (2) mapping Rounds providers via a survey, telephone interviews and secondary data; (3) a two-wave survey of (i) new attenders/non-attenders in 10 sites to determine the impact on staff engagement and well-being; and (ii) interviews with Rounds attenders, non-attenders, facilitators, clinical leads, steering group members, board members and observations in nine case study sites to (4) describe experiences and (5) test candidate programme theories by which Rounds ‘work’ (realist evaluation). Setting (1) International literature (English); (2) all Rounds providers (acute/community NHS trusts and hospices) at 1 September 2014 (survey/interview) and 15 July 2015 (secondary data); (3) 10 survey sites; and (4 and 5) nine organisational case study sites (six of which also took part in the survey). Participants (1) Ten papers were reviewed for Rounds and 146 were reviewed for alternative interventions. (2) Surveys were received from 41 out of 76 (54%) providers and interviews were conducted with 45 out of 76 (59%) providers. (3) Surveys were received from 1140 out of 3815 (30%) individuals at baseline and from 500 out of 1140 (44%) individuals at follow-up. (4 and 5) A total of 177 interviews were conducted, as were observations of 42 Rounds, 29 panel preparations and 28 steering group meetings. Results (1) The evidence base is limited; compared with 11 alternative interventions, Rounds offer a unique organisation-wide ‘all staff’ forum in which disclosure/contribution is not essential. (2) Implementation rapidly increased between 2013 and 2015; Rounds were implemented variably; challenges included ward staff attendance and the workload and resources required to sustain Rounds; and costs were widely variable. (3) There was no change in engagement, but poor psychological well-being (12-item General Health Questionnaire) reduced significantly (p < 0.05) in Rounds attenders (25% to 12%) compared with non-attenders (37% to 34%). (4 and 5) Rounds were described as interesting, engaging and supportive; four contextual layers explained the variation in Rounds implementation. We identified four stages of Rounds, ‘core’ and ‘adaptable’ components of Rounds fidelity, and nine context–mechanism–outcome configurations: (i) trust, emotional safety and containment and (ii) group interaction were prerequisites for creating (iii) a countercultural space in Rounds where staff could (iv) tell stories, (v) self-disclose their experiences to peers and (vi) role model vulnerability; (vii) provide important context for staff and patient behaviour; (viii) shining a spotlight on hidden staff and patient stories reduced isolation and enhanced support/teamwork; and (ix) staff learned through reflection resulting in ripple effects and outcomes. Reported outcomes included increased empathy and compassion for colleagues and patients, support for staff and reported changes in practice. The impact of Rounds is cumulative and we have identified the necessary conditions for Rounds to work. Limitations Rounds outcomes relied on self-report, fewer regular attenders were recruited than desired, and it was not possible to observe staff post Rounds. Conclusion Rounds offer unique support for staff and positively influence staff well-being, empathy and compassion for patients and colleagues. Future work The adaptation of Rounds to new contexts and to increase reach needs evaluation. Funding The National Institute for Health Research Health Services and Delivery Research programme

    The mechanisms and processes of connection: developing a causal chain model capturing impacts of receiving recorded mental health recovery narratives.

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    BACKGROUND: Mental health recovery narratives are a core component of recovery-oriented interventions such as peer support and anti-stigma campaigns. A substantial number of recorded recovery narratives are now publicly available online in different modalities and in published books. Whilst the benefits of telling one's story have been investigated, much less is known about how recorded narratives of differing modalities impact on recipients. A previous qualitative study identified connection to the narrator and/or to events in the narrative to be a core mechanism of change. The factors that influence how individuals connect with a recorded narrative are unknown. The aim of the current study was to characterise the immediate effects of receiving recovery narratives presented in a range of modalities (text, video and audio), by establishing the mechanisms of connection and the processes by which connection leads to outcomes. METHOD: A study involving 40 mental health service users in England was conducted. Participants were presented with up to 10 randomly-selected recovery narratives and were interviewed on the immediate impact of each narrative. Thematic analysis was used to identify the mechanisms of connection and how connection leads to outcome. RESULTS: Receiving a recovery narrative led participants to reflect upon their own experiences or those of others, which then led to connection through three mechanisms: comparing oneself with the narrative and narrator; learning about other's experiences; and experiencing empathy. These mechanisms led to outcomes through three processes: the identification of change (through attending to narrative structure); the interpretation of change (through attending to narrative content); and the internalisation of interpretations. CONCLUSIONS: This is the first study to identify mechanisms and processes of connection with recorded recovery narratives. The empirically-based causal chain model developed in this study describes the immediate effects on recipients. This model can inform selection of narratives for use in interventions, and be used to support peer support workers in recounting their own recovery narratives in ways which are maximally beneficial to others

    Staff understanding of recovery-orientated mental health practice: a systematic review and narrative synthesis

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    Background: Mental health policy is for staff to transform their practice towards a recovery orientation. Staff understanding of recovery-orientated practice will influence the implementation of this policy. The aim of this study was to conduct a systematic review and narrative synthesis of empirical studies identifying clinician and manager conceptualisations of recovery-orientated practice. Methods: A systematic review of empirical primary research was conducted. Data sources were online databases (n = 8), journal table of contents (n = 5), internet, expert consultation (n = 13), reference lists of included studies and references to included studies. Narrative synthesis was used to integrate the findings. Results: A total of 10,125 studies were screened, 245 full papers were retrieved, and 22 were included (participants, n = 1163). The following three conceptualisations of recovery-orientated practice were identified: clinical recovery, personal recovery and service-defined recovery. Service-defined recovery is a new conceptualisation which translates recovery into practice according to the goals and financial needs of the organisation. Conclusions: Organisational priorities influence staff understanding of recovery support. This influence is leading to the emergence of an additional meaning of recovery. The impact of service-led approaches to operationalising recovery-orientated practice has not been evaluated. Trial Registration: The protocol for the review was pre-registered (PROSPERO 2013: CRD42013005942)

    Recovery-based staff training intervention within mental health rehabilitation units: A two-stage analysis using realistic evaluation principles and framework approach

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    Background - Long-term change in recovery-based practice in mental health rehabilitation is a research priority. Methods - We used a qualitative case study analysis using a blend of traditional 'framework' analysis and 'realist' realist principles toapproaches to carry-out an evaluation of a recovery-focused staff training intervention within three purposively selected mental health rehabilitation units. We tried to ensure the validity of the data by using triangulation of multiple data sources and were collected using different methods. Results - We found that organisational culture and embedding of a change management programme in routine practice were reported as key influences to sustain any change in practice. The qualitative study generated 10 recommendations on how to achieve long-term change in practice including dealing with pre-existing organisational and cultural problems in NHS units. Conclusions - We would propose that a recovery-focused staff training intervention requires leadership, continuity and integration with existing change management programme for long-term change. The intervention must be embedded into routine practice for sustainability

    Using the framework method for the analysis of qualitative data in multi-disciplinary health research

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    Background: The Framework Method is becoming an increasingly popular approach to the management and analysis of qualitative data in health research. However, there is confusion about its potential application and limitations. Discussion. The article discusses when it is appropriate to adopt the Framework Method and explains the procedure for using it in multi-disciplinary health research teams, or those that involve clinicians, patients and lay people. The stages of the method are illustrated using examples from a published study. Summary. Used effectively, with the leadership of an experienced qualitative researcher, the Framework Method is a systematic and flexible approach to analysing qualitative data and is appropriate for use in research teams even where not all members have previous experience of conducting qualitative research

    Nasal Bone Shape Is under Complex Epistatic Genetic Control in Mouse Interspecific Recombinant Congenic Strains

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    Genetic determinism of cranial morphology in the mouse is still largely unknown, despite the localization of putative QTLs and the identification of genes associated with Mendelian skull malformations. To approach the dissection of this multigenic control, we have used a set of interspecific recombinant congenic strains (IRCS) produced between C57BL/6 and mice of the distant species Mus spretus (SEG/Pas). Each strain has inherited 1.3% of its genome from SEG/Pas under the form of few, small-sized, chromosomal segments.The shape of the nasal bone was studied using outline analysis combined with Fourier descriptors, and differential features were identified between IRCS BcG-66H and C57BL/6. An F2 cross between BcG-66H and C57BL/6 revealed that, out of the three SEG/Pas-derived chromosomal regions present in BcG-66H, two were involved. Segments on chromosomes 1 (∼32 Mb) and 18 (∼13 Mb) showed additive effect on nasal bone shape. The three chromosomal regions present in BcG-66H were isolated in congenic strains to study their individual effect. Epistatic interactions were assessed in bicongenic strains.Our results show that, besides a strong individual effect, the QTL on chromosome 1 interacts with genes on chromosomes 13 and 18. This study demonstrates that nasal bone shape is under complex genetic control but can be efficiently dissected in the mouse using appropriate genetic tools and shape descriptors

    Genetic randomization reveals functional relationships among morphologic and tissue-quality traits that contribute to bone strength and fragility

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    We examined femora from adult AXB/BXA recombinant inbred (RI) mouse strains to identify skeletal traits that are functionally related and to determine how functional interactions among these traits contribute to genetic variability in whole-bone stiffness, strength, and toughness. Randomization of A/J and C57BL/6J genomic regions resulted in each adult male and female RI strain building mechanically functional femora by assembling unique sets of morphologic and tissue-quality traits. A correlation analysis was conducted using the mean trait values for each RI strain. A third of the 66 correlations examined were significant, indicating that many bone traits covaried or were functionally related. Path analysis revealed important functional interactions among bone slenderness, cortical thickness, and tissue mineral density. The path coefficients describing these functional relations were similar for both sexes. The causal relationship among these three traits suggested that cellular processes during growth simultaneously regulate bone slenderness, cortical thickness, and tissue mineral density so that the combination of traits is sufficiently stiff and strong to satisfy daily loading demands. A disadvantage of these functional interactions was that increases in tissue mineral density also deleteriously affected tissue ductility. Consequently, slender bones with high mineral density may be stiff and strong but they are also brittle. Thus, genetically randomized mouse strains revealed a basic biological paradigm that allows for flexibility in building bones that are functional for daily activities but that creates preferred sets of traits under extreme loading conditions. Genetic or environmental perturbations that alter these functional interactions during growth would be expected to lead to loss of function and suboptimal adult bone quality
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