14,580 research outputs found

    Level-crossing and modal structure in microdroplet resonators

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    We fabricate a liquid-core liquid-clad microcavity that is coupled to a standard tapered fiber, and then experimentally map the whispering-gallery modes of this droplet resonator. The shape of our resonator is similar to a thin prolate spheroid, which makes space for many high-order transverse modes, suggesting that some of them will share the same resonance frequency. Indeed, we experimentally observe that more than half of the droplet's modes have a sibling having the same frequency (to within linewidth) and therefore exhibiting a standing interference-pattern

    Referral management centres as a means of reducing outpatients attendances: how do they work and what influences successful implementation and perceived effectiveness?

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    Abstract Background The rising volume of referrals to secondary care is a continuing concern in the NHS in England, with considerable resource implications. Referral management centres (RMCs) are one of a range of initiatives brought in to curtail this rise, but there is currently limited evidence for their effectiveness, and little is known about their mechanisms of action. This study aimed to gain a better understanding of how RMCs operate and the factors contributing to the achievement of their goals. Drawing on the principles of realist evaluation, we sought to elicit programme theories (the ideas and assumptions about how a programme works) and to identify the key issues to be considered when establishing or evaluating such schemes. Methods Qualitative study with a purposive sample of health professionals and managers involved in the commissioning, set-up and running of four referral management centres in England and with GPs referring through these centres. Semi-structured interviews were conducted with 18 participants. Interviews were audio-recorded and transcribed. Data were analysed thematically. Results Interview data highlighted the diverse aims and functions of RMCs, reflecting a range of underlying programme theories. These included the overarching theory that RMCs work by ensuring the best use of limited resources and three sub-theories, relating to how this could be achieved, namely, improving the quality of referrals and patient care, reducing referrals, and increasing efficiency in the referral process. The aims of the schemes, however, varied between sites and between stakeholders, and evolved significantly over time. Three themes were identified relating to the context in which RMCs were implemented and managed: the impact of practical and administrative difficulties; the importance and challenge of stakeholder buy-in; and the dependence of perceived effectiveness on the aims and priorities of the scheme. Many RMCs were described as successful by those involved, despite limited evidence of reduced referrals or cost-savings. Conclusions The findings of this study have a number of implications for the development of similar schemes, with respect to the need to ensure clarity of aims and to identify indicators of success from the outset, to anticipate scheme evolution and plan for potential changes with respect to IT systems and referral processes. Also identified, is the need for further research that evaluates the effectiveness and cost effectiveness of particular models of RMC

    Referral management centres as a means of reducing outpatients attendances: how do they work and what influences successful implementation and perceived effectiveness?

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    BACKGROUND: The rising volume of referrals to secondary care is a continuing concern in the NHS in England, with considerable resource implications. Referral management centres (RMCs) are one of a range of initiatives brought in to curtail this rise, but there is currently limited evidence for their effectiveness, and little is known about their mechanisms of action. This study aimed to gain a better understanding of how RMCs operate and the factors contributing to the achievement of their goals. Drawing on the principles of realist evaluation, we sought to elicit programme theories (the ideas and assumptions about how a programme works) and to identify the key issues to be considered when establishing or evaluating such schemes. METHODS: Qualitative study with a purposive sample of health professionals and managers involved in the commissioning, set-up and running of four referral management centres in England and with GPs referring through these centres. Semi-structured interviews were conducted with 18 participants. Interviews were audio-recorded and transcribed. Data were analysed thematically. RESULTS: Interview data highlighted the diverse aims and functions of RMCs, reflecting a range of underlying programme theories. These included the overarching theory that RMCs work by ensuring the best use of limited resources and three sub-theories, relating to how this could be achieved, namely, improving the quality of referrals and patient care, reducing referrals, and increasing efficiency in the referral process. The aims of the schemes, however, varied between sites and between stakeholders, and evolved significantly over time. Three themes were identified relating to the context in which RMCs were implemented and managed: the impact of practical and administrative difficulties; the importance and challenge of stakeholder buy-in; and the dependence of perceived effectiveness on the aims and priorities of the scheme. Many RMCs were described as successful by those involved, despite limited evidence of reduced referrals or cost-savings. CONCLUSIONS: The findings of this study have a number of implications for the development of similar schemes, with respect to the need to ensure clarity of aims and to identify indicators of success from the outset, to anticipate scheme evolution and plan for potential changes with respect to IT systems and referral processes. Also identified, is the need for further research that evaluates the effectiveness and cost effectiveness of particular models of RMC

    The psychosocial impact of home use medical devices on the lives of older people: a qualitative study

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    Background Increased life expectancy and the accompanying prevalence of chronic conditions have led to the focus and delivery of health care migrating from the hospital and into people’s homes. While previous studies have investigated the integration of particular types of medical devices into the home, it was our intention to describe how medical devices are integrated into the lives of older people. Methods Adopting a qualitative study design, 12 older people, who used medical devices in the home, took part in in-depth, semi structured interviews. In 7 of the interviews participants and their partners were interviewed together. These interviews were recorded, transcribed and analysed thematically. Results Two themes were constructed that describe how medical devices that are used in the home present certain challenges to older people and their partners in how the device is adopted and the personal adaptations that they are required to make. The first theme of 'self-esteem’ highlighted the psychological impact on users. The second theme of 'the social device' illustrated the social impact of these devices on the user and the people around them. Conclusions We found that these devices had both a positive and negative psychosocial impact on users’ lives. An improved understanding of these psychological and social issues may assist both designers of medical devices and the professionals who issue them to better facilitate the integration of medical devices into the homes and lives of older people

    Molecular Gas and Star Formation in the Cartwheel

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    Atacama Large Millimeter/submillimeter Array (ALMA) 12CO(J=1-0) observations are used to study the cold molecular ISM of the Cartwheel ring galaxy and its relation to HI and massive star formation (SF). CO moment maps find (2.69±0.05)×109(2.69\pm0.05)\times10^{9} M_{\odot} of H2_2 associated with the inner ring (72%) and nucleus (28%) for a Galactic I(CO)-to-N(H2) conversion factor (αCO\alpha_{\rm CO}). The spokes and disk are not detected. Analysis of the inner ring's CO kinematics show it to be expanding (Vexp=68.9±4.9V_{\rm exp}=68.9\pm4.9 km s1^{-1}) implying an 70\approx70 Myr age. Stack averaging reveals CO emission in the starburst outer ring for the first time, but only where HI surface density (ΣHI\Sigma_{\rm HI}) is high, representing MH2=(7.5±0.8)×108M_{\rm H_2}=(7.5\pm0.8)\times10^{8} M_{\odot} for a metallicity appropriate αCO\alpha_{\rm CO}, giving small ΣH2\Sigma_{\rm H_2} (3.73.7 M_{\odot} pc2^{-2}), molecular fraction (fmol=0.10f_{\rm mol}=0.10), and H2_2 depletion timescales (τmol50600\tau_{\rm mol} \approx50-600 Myr). Elsewhere in the outer ring ΣH22\Sigma_{\rm H_2}\lesssim 2 M_{\odot} pc2^{-2}, fmol0.1f_{\rm mol}\lesssim 0.1 and τmol140540\tau_{\rm mol}\lesssim 140-540 Myr (all 3σ3\sigma). The inner ring and nucleus are H2_2-dominated and are consistent with local spiral SF laws. ΣSFR\Sigma_{\rm SFR} in the outer ring appears independent of ΣH2\Sigma_{\rm H_2}, ΣHI\Sigma_{\rm HI} or ΣHI+H2\Sigma_{\rm HI+H_2}. The ISM's long confinement in the robustly star forming rings of the Cartwheel and AM0644-741 may result in either a large diffuse H2_2 component or an abundance of CO-faint low column density molecular clouds. The H2_2 content of evolved starburst rings may therefore be substantially larger. Due to its lower ΣSFR\Sigma_{\rm SFR} and age the Cartwheel's inner ring has yet to reach this state. Alternately, the outer ring may trigger efficient SF in an HI-dominated ISM.Comment: 10-pages text; 5-figure

    Medical device design for adolescent adherence and developmental goals: a case study of a cystic fibrosis physiotherapy device

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    Purpose: This study investigates the psychosocial aspects of adolescent medical device use and the impact on adolescent adherence and goals for the transitional years between child and adulthood. Patients and methods: Interviews were carried out with 20 adolescents with cystic fibrosis, investigating adolescent medical device use and experiences in relation to their personal and social lives and development through the adolescent years. The qualitative dataset was thematically examined using a content analysis method. Results: The results show that adolescent users of medical technologies want their independence and capabilities to be respected. Adolescent adherence to medical device use was associated with short- and long-term motivations, where older adolescents were able to comprehend the longer-term benefits of use against short-term inconvenience more acutely than younger adolescents. It was suggested that medical devices could provide a tool for communication with families and clinicians and could support adolescents as they take responsibility for managing their condition. Themes of “fitting into teenage life” and “use in the community” were associated with adolescents' needs to form their own identity and have autonomy. Conclusion: This study shows that adolescent needs regarding medical device use are complex. It provides evidence to suggest that devices designed inclusively for adolescents may lead to improved adherence and also facilitate transition through the adolescent years and achievement of adolescent goals

    Surface Gravities for 228 M, L, and T Dwarfs in the NIRSPEC Brown Dwarf Spectroscopic Survey

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    We combine 131 new medium-resolution (R~2000) J-band spectra of M, L, and T dwarfs from the Keck NIRSPEC Brown Dwarf Spectroscopic Survey (BDSS) with 97 previously published BDSS spectra to study surface-gravity-sensitive indices for 228 low-mass stars and brown dwarfs spanning spectral types M5-T9. Specifically, we use an established set of spectral indices to determine surface gravity classifications for all M6-L7 objects in our sample by measuring equivalent widths (EW) of the K I lines at 1.1692, 1.1778, 1.2529 um, and the 1.2 um FeHJ absorption index. Our results are consistent with previous surface gravity measurements, showing a distinct double peak - at ~L5 and T5 - in K I EW as a function of spectral type. We analyze K I EWs of 73 objects of known ages and find a linear trend between log(Age) and EW. From this relationship, we assign age ranges to the very low gravity, intermediate gravity, and field gravity designations for spectral types M6-L0. Interestingly, the ages probed by these designations remain broad, change with spectral type, and depend on the gravity sensitive index used. Gravity designations are useful indicators of the possibility of youth, but current datasets cannot be used to provide a precise age estimate.Comment: 33 pages, 13 figures, ApJ in pres

    1.6 W continuous-wave Raman laser using low-loss synthetic diamond

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    Low-birefringence (Δn<2x10−6), low-loss (absorption coefficient <0.006cm−1 at 1064nm), single-crystal, synthetic diamond has been exploited in a CW Raman laser. The diamond Raman laser was intracavity pumped within a Nd:YVO4 laser. At the Raman laser wavelength of 1240nm, CW output powers of 1.6W and a slope efficiency with respect to the absorbed diode-laser pump power (at 808nm) of ~18% were measured. In quasi-CW operation, maximum on-time output powers of 2.8W (slope efficiency ~24%) were observed, resulting in an absorbed diode-laser pump power to the Raman laser output power conversion efficiency of 13%
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