1,383 research outputs found

    A simple formula for pooling knowledge about a quantum system

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    When various observers obtain information in an independent fashion about a classical system, there is a simple rule which allows them to pool their knowledge, and this requires only the states-of-knowledge of the respective observers. Here we derive an equivalent quantum formula. While its realm of applicability is necessarily more limited, it does apply to a large class of measurements, and we show explicitly for a single qubit that it satisfies the intuitive notions of what it means to pool knowledge about a quantum system. This analysis also provides a physical interpretation for the trace of the product of two density matrices.Comment: 5 pages, Revtex

    Detectors for leptonic CP violation at the neutrino factory

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    Studies carried out in the framework of the International Design Study for the Neutrino Factory (the IDS-NF) show that the sensitivity to the CP violating phase and the last unknown mixing angle θ13 is maximised when two far detectors optimized to detect the sub-leading νe to νμ oscillation are combined. Several technologies are being discussed for these detectors: magnetised iron calorimeters; giant liquid argon TPCs; and totally active scintillating detectors. The IDS-NF baseline option, a compromise between feasibility, cost, and performance, is documented in the Interim Design Report (IDR) that has recently been completed. It consists of two magnetised iron sampling calorimeters, similar to the existing MINOS detector, but with 10-20 times more mass and improved performance. A detector of mass 100 kton is assumed at the intermediate baseline (between 2500 km and 5000 km) and a 50 kton detector at the long baseline (between 7000 km and 8000 km). The other far-detector options, which have better granularity, may be able to detect additional oscillation channels, thus improving the overall performance of the facility. However, these options are likely to be more expensive and require significant R&D

    Forward Flux Sampling-type schemes for simulating rare events: Efficiency analysis

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    We analyse the efficiency of several simulation methods which we have recently proposed for calculating rate constants for rare events in stochastic dynamical systems, in or out of equilibrium. We derive analytical expressions for the computational cost of using these methods, and for the statistical error in the final estimate of the rate constant, for a given computational cost. These expressions can be used to determine which method to use for a given problem, to optimize the choice of parameters, and to evaluate the significance of the results obtained. We apply the expressions to the two-dimensional non-equilibrium rare event problem proposed by Maier and Stein. For this problem, our analysis gives accurate quantitative predictions for the computational efficiency of the three methods.Comment: 19 pages, 13 figure

    Potential role for clinical calibration to increase engagement with and application of home telemonitoring: a report from the HeartCycle programme

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    Aims: There is a need for alternative strategies that might avoid recurrent admissions in patients with heart failure. Home Telemonitoring (HTM) to monitor patient’s symptoms from a distance may be useful. This study attempts to assess changes in HTM vital signs in response to daily life activities (variations in medication, salt intake, exercise and stress) and to stablish which variations affect weight, blood pressure (BP) and heart rate (HR). Methods and results: We assessed 76 patients with heart failure (mean age 76 ± 10.8 years, 75% male, mainly in NYHA class II/III and from ischaemic etiology cause). Patients were given a calendar of interventions scheduling activities approximately twice-a-week before measuring their vital signs. Eating salty food or a large meal were the activities that had a significant impact on weight gain (+0.3 kg; p<0.001 and p=0.006, respectively). Exercise and skipping a dose of medication other than diuretics increased heart rate (+3 bpm, p=0.001 and almost +2 bpm, p=0.016, respectively). Conclusions: Our HTM system was able to detect small changes in vital signs related to these activities. Further studies should assess if providing such a schedule of activities might be useful for patient education and could improve long-term adherence to recommended lifestyle changes

    Overlapping Effects of miR-21 Inhibition and Drugs for Idiopathic Pulmonary Fibrosis: Rationale for Repurposing Nintedanib as a Novel Treatment for Ischemia/Reperfusion Injury

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    ABSTRACT: A specific anti-miR-21 has emerged as an effective treatment for ischemia/reperfusion injury in a pig model of myocardial infarction (MI), but the perspectives for clinical translation are limited. Anti-miR-21 blunts profibrotic pathways, whose excessive activation is detrimental in the post-MI setting. Repurposing antifibrotic drugs approved for other indications is a possible strategy. We compared the molecular effects of anti-miR-21 and the 2 drugs approved for idiopathic pulmonary fibrosis (nintedanib and pirfenidone) through a bioinformatic approach. We report that nintedanib and anti-miR-21 share many targets, including the proto-oncogene Rous sarcoma oncogene cellular homolog. Conversely, pirfenidone and anti-miR-21 do not have common mechanisms of action. In summary, the molecular mechanisms activated by nintedanib are partially overlapping with those elicited by anti-miR-21. Nintedanib could be evaluated in animal studies or clinical trials on MI

    The health care utilisation and out-of-pocket expenditure associated with Australian stroke survivors aged 55 and over.

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    OBJECTIVE: Stroke is a major cause of mortality and disability worldwide. People with stroke have a number of options available to treat post-stroke related symptoms and challenges. The aim of this study was to assess the use of healthcare services, self-care practices and out-of-pocket expenses associated with post-stroke healthcare. METHODS: We retrospectively analysed data collected between April and October 2017 from a survey of 576 participants aged 55 to 96 from the 45 and Up Study, NSW (Australia), who had earlier reported a clinical diagnosis of stroke. Participants were asked about their use of health care services, including conventional medicine practitioners and medications, complementary medicine practitioners, practices and products and the respective associated out-of-pocket expenditure for each. RESULTS: Amongst the total of 576 individuals who participated in the study, 39% consulted a doctor, 18% consulted an allied health practitioner, and 8% consulted a complementary medicine practitioner in the previous year for their stroke. Participants' average combined out-of-pocket expenditure for post-stroke related healthcare was AU386.4perannum.ExtrapolatedtoallAustralianswithstroke,aged55yearsandover,thetotaloutofpocketexpenditureforpoststrokerelatedhealthcareisestimatedtobeAU386.4 per annum. Extrapolated to all Australians with stroke, aged 55 years and over, the total out-of-pocket expenditure for post-stroke related healthcare is estimated to be AU42 million per annum. CONCLUSIONS: Post-stroke individuals used a wide range of health services and various self-care practices for stroke rehabilitation. Such healthcare utilisation is associated with significant annual out-of-pocket expenditure. Given the socioeconomic burden of stroke, further research is required to identify the barriers and facilitators of self-care among patients with stroke and explore the cost-effectiveness of the wide range of treatments(s) utilised for post-stroke care

    Helping parents know when to seek help for an acutely ill child: Evidence based co-development of a mobile phone app using complex intervention methodology.

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    BACKGROUND: Acute illness accounts for the majority of episodes of illness in children under five years of age and is the age group with the highest consultation rate in general practice in the UK. The number of children presenting to emergency care is also steadily increasing, having risen beyond pre-pandemic numbers. Such high, and increasing, rates of consultation have prompted concerns about parents' level of knowledge and confidence in caring for their children when they are ill, and particularly when and how to seek help appropriately. AIM: The ASK SNIFF collaboration research programme identified parents' need for accurate and accessible information to help them know when to seek help for a sick child in 2010. This paper presents the resulting programme of research which aimed to co-develop an evidence-based safety netting intervention (mobile app) to help parents know when to seek help for an acutely ill child under the age of five years in the UK. METHODS: Our programme used a collaborative six step process with 147 parent and 324 health professional participants over a period of six years including: scoping existing interventions, systematic review, qualitative research, video capture, content identification and development, consensus methodology, parent and expert clinical review. RESULTS: Our programme has produced evidence-based content for an app supported by video clips. Our collaborative approach has supported every stage of our work, ensuring that the end result reflects the experiences, perspectives and expressed needs of parents and the clinicians they consult. CONCLUSION: We have not found any other resource which has used this type of approach, which may explain why there is no published evaluation data demonstrating the impact of existing UK resources. Future mobile apps should be designed and developed with the service users for whom they are intended

    Longitudinal muon spin relaxation in high purity aluminum and silver

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    The time dependence of muon spin relaxation has been measured in high purity aluminum and silver samples in a longitudinal 2 T magnetic field at room temperature, using time-differential \musr. For times greater than 10 ns, the shape fits well to a single exponential with relaxation rates of \lambda_{\textrm{Al}} = 1.3 \pm 0.2\,(\textrm{stat.}) \pm 0.3\,(\textrm{syst.})\,\pms and \lambda_{\textrm{Ag}} = 1.0 \pm 0.2\,(\textrm{stat.}) \pm 0.2\,(\textrm{syst.})\,\pms

    Fitting in a complex chi^2 landscape using an optimized hypersurface sampling

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    Fitting a data set with a parametrized model can be seen geometrically as finding the global minimum of the chi^2 hypersurface, depending on a set of parameters {P_i}. This is usually done using the Levenberg-Marquardt algorithm. The main drawback of this algorithm is that despite of its fast convergence, it can get stuck if the parameters are not initialized close to the final solution. We propose a modification of the Metropolis algorithm introducing a parameter step tuning that optimizes the sampling of parameter space. The ability of the parameter tuning algorithm together with simulated annealing to find the global chi^2 hypersurface minimum, jumping across chi^2{P_i} barriers when necessary, is demonstrated with synthetic functions and with real data

    North-central Nigerian women’s experiences of obstetric fistula risk factors and their perceived treatment services: An interpretive description

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    Background An obstetric fistula also known as vesico vaginal fistula (VVF), or recto-vaginal fistula (RVF) is an abnormal opening between the urogenital tract and intestinal tract caused by prolonged obstructed labour; when the head of the baby presses on the soft tissues in the pelvis leading to loss of blood flow to the women’s bladder, vagina, and rectum. This can cause necrosis of the soft tissues resulting in debilitating fistula formations. Aim This study aimed to uncover North-central Nigerian women’s experiences of obstetric fistula and their perceived treatment services. Design Qualitative, interpretive descriptive methodology underpinned by symbolic interactionism involving face-to-face semi-structured interviews was used to explore North-central Nigerian women’s experiences of obstetric fistula and their perceived treatment services. Sample A purposive sample of 15 women who had experienced obstetric fistula at a repair Centre in North-central Nigeria were eligible. Results Four themes emerged from North-central Nigerian women’s experiences of obstetric fistula and their perceived treatment services i) I was left alone in the room ii) Waiting for the one vehicle in the village iii) I never knew about labour until that very day iv) and We kept following the native doctors and sorcerers. Conclusion The findings from this study highlighted the depth of women’s experiences from the devastating complication of childbirth injury in North-central Nigeria. Analysis of insights from women’s voices directly affected by obstetric fistula demonstrated that in their views and experiences the themes identified were majorly responsible for their fistula status. Thus women need to raise their collective voices to resist oppressive harmful traditions and demand empowerment opportunities that will improve their social status. Government should improve primary healthcare facilities, train more midwives and subsidise maternal care for antenatal education and birth services spending for childbirth women may result in improved childbirth experiences for women in rural and urban communities. Tweetable Abstract Reproductive women call for increased accessibility to healthcare services and the provision of more midwives to mitigate obstetric fistula in North-central Nigerian communities
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