857 research outputs found

    Starting early: integration of self-management support into an acute stroke service.

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    Self-management support following stroke is rare, despite emerging evidence for impact on patient outcomes. The promotion of a common approach to self-management support across a stroke pathway requires collaboration between professionals. To date, the feasibility of self-management support in acute stroke settings has not been evaluated. The Bridges stroke self-management package (SMP) is based on self-efficacy principles. It is delivered by professionals and supported by a patient-held workbook. The aim of this project was to introduce the Bridges stroke SMP to the multidisciplinary staff of a London hyperacute and acute stroke unit. The 'Plan Do Study Act' (PDSA) cycle guided iterative stages of project development, with normalisation process theory helping to embed the intervention into existing ways of working. Questionnaires explored attitudes, beliefs and experiences of the staff who were integrating self-management support into ways of working in the acute stroke setting. Self-management support training was delivered to a total of 46 multidisciplinary stroke staff. Of the staff who attended the follow-up training, 66% had implemented Bridges self-management support with patients since initial training, and 100% felt their practice had changed. Questionnaire findings demonstrated that staff attitudes and beliefs had changed following training, particularly regarding ownership and type of rehabilitation goals set, and prioritisation of self-management support within acute stroke care. Staff initiated an audit of washing and dressing practices pre- and post-training. This was designed to evaluate the number of occasions when techniques were used by staff to facilitate patients' independence and self-management. They found that the number of occasions featuring optimum practice went from 54% at baseline to 63% at three months post-training. This project demonstrated the feasibility of integrating self-management support into an acute stroke setting. Further work is required to evaluate sustainability of the Bridges stroke SMP, to understand the barriers and opportunities involved in engaging all professional groups in integrated self-management support in acute stroke settings, and to assess patient reported outcomes

    Regge calculus from a new angle

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    In Regge calculus space time is usually approximated by a triangulation with flat simplices. We present a formulation using simplices with constant sectional curvature adjusted to the presence of a cosmological constant. As we will show such a formulation allows to replace the length variables by 3d or 4d dihedral angles as basic variables. Moreover we will introduce a first order formulation, which in contrast to using flat simplices, does not require any constraints. These considerations could be useful for the construction of quantum gravity models with a cosmological constant.Comment: 8 page

    A next-generation inverse-geometry spallation-driven ultracold neutron source

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    The physics model of a next-generation spallation-driven high-current ultracold neutron (UCN) source capable of delivering an extracted UCN rate of around an-order-of-magnitude higher than the strongest proposed sources, and around three-orders-of-magnitude higher than existing sources, is presented. This UCN-current-optimized source would dramatically improve cutting-edge UCN measurements that are currently statistically limited. A novel "Inverse Geometry" design is used with 40 L of superfluid 4^4He (He-II), which acts as a converter of cold neutrons (CNs) to UCNs, cooled with state-of-the-art sub-cooled cryogenic technology to \sim1.6 K. Our design is optimized for a 100 W maximum heat load constraint on the He-II and its vessel. In our geometry, the spallation target is wrapped symmetrically around the UCN converter to permit raster scanning the proton beam over a relatively large volume of tungsten spallation target to reduce the demand on the cooling requirements, which makes it reasonable to assume that water edge-cooling only is sufficient. Our design is refined in several steps to reach PUCN=2.1×109/P_{UCN}=2.1\times10^9\,/s under our other restriction of 1 MW maximum available proton beam power. We then study effects of the He-II scattering kernel as well as reductions in PUCNP_{UCN} due to pressurization to reach PUCN=1.8×109/P_{UCN}=1.8\times10^9\,/s. Finally, we provide a design for the UCN extraction system that takes into account the required He-II heat transport properties and implementation of a He-II containment foil that allows UCN transmission. We estimate a total useful UCN current from our source of Ruse=5×108/R_{use}=5\times10^8\,/s from a 18 cm diameter guide 5 m from the source. Under a conservative "no return" approximation, this rate can produce an extracted density of >1×104/>1\times10^4\,/cm3^3 in <<1000~L external experimental volumes with a 58^{58}Ni (335 neV) cut-off potential.Comment: Submitted to Journal of Applied Physic

    Ultracold Neutron Production in a Pulsed Neutron Beam Line

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    We present the results of an Ultracold neutron (UCN) production experiment in a pulsed neutron beam line at the Los Alamos Neutron Scattering Center. The experimental apparatus allows for a comprehensive set of measurements of UCN production as a function of target temperature, incident neutron energy, target volume, and applied magnetic field. However, the low counting statistics of the UCN signal expected can be overwhelmed by the large background associated with the scattering of the primary cold neutron flux that is required for UCN production. We have developed a background subtraction technique that takes advantage of the very different time-of-flight profiles between the UCN and the cold neutrons, in the pulsed beam. Using the unique timing structure, we can reliably extract the UCN signal. Solid ortho-D2_2 is used to calibrate UCN transmission through the apparatus, which is designed primarily for studies of UCN production in solid O2_2. In addition to setting the overall detection efficiency in the apparatus, UCN production data using solid D2_2 suggest that the UCN upscattering cross-section is smaller than previous estimates, indicating the deficiency of the incoherent approximation widely used to estimate inelastic cross-sections in the thermal and cold regimes

    Is Inferior Mesenteric Artery Embolization Indicated Prior to Endovascular Repair of Abdominal Aortic Aneurysm?

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    Type II endoleak is a common condition occurring after endovascular repair of abdominal aortic aneurysms (EVAR), and may result in aneurysm sac growth and/or rupture in a small number of patients. A prophylactic strategy of inferior mesenteric artery (IMA) embolization before EVAR has been advocated, however, the benefits of this strategy are controversial. A clinical vignette allows the authors to summarize the available data about this issue and discuss the possible benefits and risks of prophylactic IMA embolization before EVAR. The authors performed a meta-analysis of available data which showed that the pooled rate of type II endoleak after IMA embolization was 19.9% (95% Cl 3.4-34.7%, I-2 93%) whereas it was 41.4% (95% Cl 30.4-52.3%, I-2 76%) in patients without IMA embolization (5 studies including 596 patients: p <.0001, OR 0.369, 95% Cl 0.22-0.61, I-2 27%). Since treatment for type II endoleaks is needed in less than 20% of cases and this complication can be treated successfully in 60-70% of cases resulting in an aneurysm rupture risk of 0.9%, these data indicate that embolization of patent IMA may be of no benefit in patients undergoing EVAR. (C) 2015 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.Peer reviewe

    Supporting self-management after traumatic brain injury : codesign and evaluation of a new intervention across a trauma pathway

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    Background Supported self‐management (SSM) is a recognized approach for people with long‐term conditions but, despite the prevalence of unmet needs, little is known about its role for people with traumatic brain injury (TBI). Objectives To codesign an SSM intervention with people with TBI and evaluate feasibility of implementation through multidisciplinary staff across a trauma pathway. Setting and participants People who had previously been admitted to a Major Trauma Centre following TBI and family members participated in a series of codesign activities. Staff attended SSM workshops and used the intervention with patients in acute and rehabilitation settings. Methods We used Normalization Process Theory constructs to guide and interpret implementation. Knowledge, beliefs and confidence of staff in SSM were assessed through pre‐ and post‐training questionnaires, and staff, patients' and families' experiences were explored through semi‐structured interviews. Qualitative data were analysed thematically, and clinical measures were mapped against a matched sample. Results Codesigned resources were created and used within an SSM approach for which 110 staff participated in training. Evaluation demonstrated significant differences in staff SSM confidence and skills, following training. Qualitative evaluation revealed adoption by staff, and patients' and families' experiences of using the resources. Challenges included reaching staff across complex pathways to achieve collective implementation. Conclusion This is the first project to demonstrate feasibility of SSM for people after TBI starting in an acute trauma setting. Through an open approach to codesign with a marginalized group, the SSM resources were valued by them and held meaning and relevance for staff

    Effective action and semiclassical limit of spin foam models

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    We define an effective action for spin foam models of quantum gravity by adapting the background field method from quantum field theory. We show that the Regge action is the leading term in the semi-classical expansion of the spin foam effective action if the vertex amplitude has the large-spin asymptotics which is proportional to an exponential function of the vertex Regge action. In the case of the known three-dimensional and four-dimensional spin foam models this amounts to modifying the vertex amplitude such that the exponential asymptotics is obtained. In particular, we show that the ELPR/FK model vertex amplitude can be modified such that the new model is finite and has the Einstein-Hilbert action as its classical limit. We also calculate the first-order and some of the second-order quantum corrections in the semi-classical expansion of the effective action.Comment: Improved presentation, 2 references added. 15 pages, no figure

    Area-angle variables for general relativity

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    We introduce a modified Regge calculus for general relativity on a triangulated four dimensional Riemannian manifold where the fundamental variables are areas and a certain class of angles. These variables satisfy constraints which are local in the triangulation. We expect the formulation to have applications to classical discrete gravity and non-perturbative approaches to quantum gravity.Comment: 7 pages, 1 figure. v2 small changes to match published versio

    The Seroepidemiology of Haemophilus influenzae Type B Prior to Introduction of an Immunization Programme in Kathmandu, Nepal.

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    Haemophilus influenzae type b (Hib) is now recognized as an important pathogen in Asia. To evaluate disease susceptibility, and as a marker of Hib transmission before routine immunization was introduced in Kathmandu, 71 participants aged 7 months-77 years were recruited and 15 cord blood samples were collected for analysis of anti-polyribosylribitol phosphate antibody levels by enzyme-linked immunosorbent assay. Only 20% of children under 5 years old had levels considered protective (>0.15 µg/ml), rising to 83% of 15-54 year-olds. Prior to introduction of Hib vaccine in Kathmandu, the majority of young children were susceptible to disease
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