1,079 research outputs found

    Cumulative luminosity functions of the X-ray point source population in M31

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    We present preliminary results from a detailed analysis of the X-ray point sources in the XMM-Newton survey of M31. These sources are expected to be mostly X-ray binaries. We have so far studied 225 of the 535 sources found by automated source detection. Only sources which were present in all three EPIC images were considered. X-ray binaries are identified by their energy spectrum and power density spectrum. Unlike in other surveys we have obtained source luminosities from freely fit emission models. We present uncorrected luminosity functions of the sources analysed so far.Comment: 2 pages, 1 figure. To appear in proceedings of IAUS23

    Which lipid measurement should we monitor? An analysis of the LIPID study

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    OBJECTIVES: To evaluate the optimal lipid to measure in monitoring patients, we assessed three factors that influence the choice of monitoring tests: (1) clinical validity; (2) responsiveness to therapy changes and (3) the size of the long-term ‘signal-to-noise’ ratio. DESIGN: Longitudinal analyses of repeated lipid measurement over 5 years. SETTING: Subsidiary analysis of a Long-Term Intervention with Pravastatin in Ischaemic Disease (LIPID) study—a clinical trial in Australia, New Zealand and Finland. PARTICIPANTS: 9014 patients aged 31–75 years with previous acute coronary syndromes. INTERVENTIONS: Patients were randomly assigned to 40 mg daily pravastatin or placebo. PRIMARY AND SECONDARY OUTCOME MEASURES: We used data on serial lipid measurements—at randomisation, 6 months and 12 months, and then annually to 5 years—of total cholesterol; low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol and their ratios; triglycerides; and apolipoproteins A and B and their ratio and their ability to predict coronary events. RESULTS: All the lipid measures were statistically significantly associated with future coronary events, but the associations between each of the three ratio measures (total or LDL cholesterol to HDL cholesterol, and apolipoprotein B to apolipoprotein A1) and the time to a coronary event were better than those for any of the single lipid measures. The two cholesterol ratios also ranked highly for the long-term signal-to-noise ratios. However, LDL cholesterol and non-HDL cholesterol showed the most responsiveness to treatment change. CONCLUSIONS: Lipid monitoring is increasingly common, but current guidelines vary. No single measure was best on all three criteria. Total cholesterol did not rank highly on any single criterion. However, measurements based on cholesterol subfractions—non-HDL cholesterol (total cholesterol minus HDL cholesterol) and the two ratios—appeared superior to total cholesterol or any of the apolipoprotein options. Guidelines should consider using non-HDL cholesterol or a ratio measure for initial treatment decisions and subsequent monitoring

    XMM-Newton reveals ~100 new LMXBs in M31 from variability studies

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    We have conducted a survey of X-ray sources in XMM-Newton observations of M31, examining their power density spectra (PDS) and spectral energy distributions (SEDs). Our automated source detection yielded 535 good X-ray sources; to date, we have studied 225 of them. In particular, we examined the PDS because low mass X-ray binaries (LMXBs) exhibit two distinctive types of PDS. At low accretion rates, the PDS is characterised by a broken power law, with the spectral index changing from ~0 to ~1 at some frequency in the range \~0.01--1 Hz; we refer to such PDS as Type A. At higher accretion rates, the PDS is described by a simple power law; we call these PDS Type B. Of the 225 sources studied to date, 75 exhibit Type A variability, and are almost certainly LMXBs, while 6 show Type B but not Type A, and are likely LMXBs. Of these 81 candidate LMXBs, 71 are newly identified in this survey; furthermore, they are mostly found near the centre of M31. Furthermore, most of the X-ray population in the disc are associated with the spiral arms, making them likely high mass X-ray binaries (HMXBs). In general these HMXBs do not exhibit Type A variability, while many central X-ray sources (LMXBs) in the same luminosity range do. Hence the PDS may distinguish between LMXBs and HMXBs in this luminosity range.Comment: 4 pages, 2 figures. To appear in proceedings of IAUS230: "Populations of High Energy Sources in Galaxies", 14-19 August 2005, Dublin, Eds E.J.A. Meurs and G. Fabbian

    Investigating the mechanism of impact of the quality premium initiative on antibiotic prescribing in primary care practices in England: a study protocol

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    Introduction The persistent development and spread of resistance to antibiotics remains an important public health concern in the UK and globally. About 74% of antibiotics prescribed in England in 2016 was in primary care. The Quality Premium (QP) initiative that rewards Clinical Commissioning Groups (CCGs) financially based on the quality of specific health services commissioned is one of the National Health Service (NHS) England interventions to reduce antimicrobial resistance through reduced prescribing. Emerging evidence suggests a reduction in antibiotic prescribing in primary care practices in the UK following QP initiative. This study aims to investigate the mechanism of impact of this high-cost health-system level intervention on antibiotic prescribing in primary care practices in England. Methods and analysis The study will constitute secondary analyses of antibiotic prescribing data for almost all primary care practices in England from the NHS England Antibiotic Quality Premium Monitoring Dashboard and OpenPrescribing covering the period 2013 to 2018. The primary outcome is the number of antibiotic items per Specific Therapeutic group Age-sex Related Prescribing Unit (STAR-PU) prescribed monthly in each practice or CCG. We will first conduct an interrupted time series using Ordinary Least Square regression method to examine whether antibiotic prescribing rate in England has changed over time, and how such changes, if any, are associated with QP implementation. Single and sequential multiple-mediator models using a unified approach for the natural direct and indirect effects will be conducted to investigate the relationship between QP initiative, the potential mediators and antibiotic prescribing rate with adjustment for practice and CCG characteristics. Ethics and dissemination This study will use secondary data that are anonymised and obtained from studies that have either undergone ethical review or generated data from routine collection systems. Multiple channels will be used in disseminating the findings from this study to academic and non-academic audiences. Strengths and Limitations of this study • This study will be the first to evaluate the mechanism of the impact of a financial incentive initiative involving Clinical Commissioning Groups to improve antibiotic prescribing in primary care practices in England. • The investigation of multiple mediators in this study will help to identify the contributions of multiple strategies in translating the effects of QP while unpacking the extent of the effect of specific mediators. • Due to the limited data on practice-level interventions or strategies that might potentially mediate the effect of the QP on antibiotic prescribing, we will not be able to extensively investigate the mechanism of QP impact at the practice level. • Nevertheless, extensive investigations will be conducted at CCG level where the Quality Premium initiative is implemented, and rewards paid out

    Would you like to sample'l Robot engagement in a shopping centre

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    © 2017 IEEE. Nowadays, robots are gradually appearing in public spaces such as libraries, train stations, airports and shopping centres. Only a limited percentage of research literature explores robot applications in public spaces. Studying robot applications in the wild is particularly important for designing commercially viable applications able to meet a specific goal. Therefore, in this paper we conduct an experiment to test a robot application in a shopping centre, aiming to provide results relevant for today's technological capability and market. We compared the performance of a robot and a human in promoting food samples in a shopping centre, a well known commercial application, and then analysed the effects of the type of engagement used to achieve this goal. Our results show that the robot is able to engage customers similarly to a human as expected. However unexpectedly, while an actively engaging human was able to perform better than a passively engaging human, we found the opposite effect for the robot. In this paper we investigate this phenomenon, with possible explanation ready to be explored and tested in subsequent research

    Using networked technologies to support conferences

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    Using networked technologies to support conferences

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    The increasing availability of WiFi networks in conference venues is an opportunity to provide additional services for conference delegates and to enhance and enrich the learning experience. This paper reviews experiences of use of networked applications in a conference environment and outlines a number of potentially useful technologies. The paper addresses potential concerns over use of networked technologies including the dangers of disruption and distraction, legal and copyright issues as well as the danger of being over-fixated on the technologies themselves, rather than the uses they can provide. The paper concludes by summarising the issues which need to be addressed when considering the provision of networked services in a conference setting

    A systematic review of air pollution and incidence of out-of-hospital cardiac arrest

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    Introduction: Studies have linked air pollution with the incidence of acute coronary artery events and cardiovascular mortality but the association with out-of-hospital cardiac arrest (OHCA) is less clear. Aim: To examine the association of air pollution with the occurrence of OHCA.Methods: Electronic bibliographic databases (until February 2013) were searched. Search terms included common air pollutants and OHCA. Studies of patients with implantable cardioverter defibrillators and OHCA not attended by paramedics were excluded. Two independent reviewers (THKT and TAW) identified potential studies. Methodological: quality was assessed by the Newcastle-Ottawa Scale.Results: Of 849 studies, 8 met the selection criteria. Significant associations between particulate matter (PM) exposure (especially PM2.5) and OHCA were found in 5 studies. An increase of OHCA risk ranged from 2.4% to 7% per interquartile increase in average PM exposure on the same day and up to 4 days prior to the event. A large study found ozone increased the risk of OHCA within 3 h prior to the event. The strongest risk OR of 3.8–4.6% per 20 parts per billion ozone increase of the average level was within 2 h prior to the event. Similarly, another study found an increased risk of 18% within 2 days prior to the event.Conclusions: Larger studies have suggested an increased risk of OHCA with air pollution exposure from PM 2.5 and ozone
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