23 research outputs found

    A Multi-band Study of the Remarkable Jet in Quasar 4C+19.44

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    We present arcsecond-resolution data in the radio, IR, optical, and X-ray for 4C+19.44 (=PKS 1354+195), the longest and straightest quasar jet with deep X-ray observations. We report results from radio images with half to one arcsecond angular resolution at three frequencies, plus Hubble Space Telescope and Spitzer data. The Chandra data allow us to measure the X-ray spectral index in 10 distinct regions along the 18'' jet and compare with the radio index. The radio and X-ray spectral indices of the jet regions are consistent with a value of α=0.80\alpha =0.80 throughout the jet, to within 2σ2\sigma uncertainties. The X-ray jet structure to the south extends beyond the prominent radio jet and connects to the southern radio lobe, and there is extended X-ray emission, both in the direction of the unseen counter-jet, and also coincident with the northern radio lobe. This jet is remarkable because its straight appearance over a large distance allows the geometry factors to be taken as fixed along the jet. Using the model of inverse Compton scattering of the cosmic microwave background (iC/CMB) by relativistic electrons, we find that the magnetic field strengths and Doppler factors are relatively constant along the jet. If instead the X-rays are synchrotron emission, they must arise from a population of electrons distinct from the particles producing the radio synchrotron spectrum

    Overriding water table control on managed peatland greenhouse gas emissions

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    Global peatlands store more carbon than is naturally present in the atmosphere1,2. However, many peatlands are under pressure from drainage-based agriculture, plantation development and fire, with the equivalent of around 3% of all anthropogenic greenhouse gases emitted from drained peatland3–5. Efforts to curb such emissions are intensifying through the conservation of undrained peatlands and rewetting of drained systems6. Here we report CO2 eddy covariance data from 16 locations and CH4 data from 41 locations in the British Isles, and combine them with published data from sites across all major peatland biomes. We find that the mean annual effective water-table depth (WTDe; that is, the average depth of the aerated peat layer) overrides all other ecosystem- and management-related controls on greenhouse gas fluxes. We estimate that every 10 cm of reduction in WTDe could reduce the net warming impact of CO2 and CH4 emissions (100-year Global Warming Potentials) by at least 3 t CO2e ha-1 yr-1, until WTDe is < 30 cm. Raising water levels further would continue to have a net cooling effect until WTDe is < 10 cm. Our results suggest that greenhouse gas emissions from peatlands drained for agriculture could be greatly reduced without necessarily halting their productive use. Halving WTDe in all drained agricultural peatlands, for example, could reduce emissions by the equivalent of over 1% of global anthropogenic emissions

    Structured lifestyle education to support weight loss for people with schizophrenia, schizoaffective disorder and first episode psychosis: the STEPWISE RCT.

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    BACKGROUND: Obesity is twice as common in people with schizophrenia as in the general population. The National Institute for Health and Care Excellence guidance recommends that people with psychosis or schizophrenia, especially those taking antipsychotics, be offered a healthy eating and physical activity programme by their mental health care provider. There is insufficient evidence to inform how these lifestyle services should be commissioned. OBJECTIVES: To develop a lifestyle intervention for people with first episode psychosis or schizophrenia and to evaluate its clinical effectiveness, cost-effectiveness, delivery and acceptability. DESIGN: A two-arm, analyst-blind, parallel-group, randomised controlled trial, with a 1 : 1 allocation ratio, using web-based randomisation; a mixed-methods process evaluation, including qualitative case study methods and logic modelling; and a cost-utility analysis. SETTING: Ten community mental health trusts in England. PARTICIPANTS: People with first episode psychosis, schizophrenia or schizoaffective disorder. INTERVENTIONS: Intervention group: (1) four 2.5-hour group-based structured lifestyle self-management education sessions, 1 week apart; (2) multimodal fortnightly support contacts; (3) three 2.5-hour group booster sessions at 3-monthly intervals, post core sessions. Control group: usual care assessed through a longitudinal survey. All participants received standard written lifestyle information. MAIN OUTCOME MEASURES: The primary outcome was change in weight (kg) at 12 months post randomisation. The key secondary outcomes measured at 3 and 12 months included self-reported nutrition (measured with the Dietary Instrument for Nutrition Education questionnaire), objectively measured physical activity measured by accelerometry [GENEActiv (Activinsights, Kimbolton, UK)], biomedical measures, adverse events, patient-reported outcome measures and a health economic assessment. RESULTS: The trial recruited 414 participants (intervention arm: 208 participants; usual care: 206 participants) between 10 March 2015 and 31 March 2016. A total of 341 participants (81.6%) completed the trial. A total of 412 participants were analysed. After 12 months, weight change did not differ between the groups (mean difference 0.0 kg, 95% confidence interval -1.59 to 1.67 kg; p = 0.964); physical activity, dietary intake and biochemical measures were unchanged. Glycated haemoglobin, fasting glucose and lipid profile were unchanged by the intervention. Quality of life, psychiatric symptoms and illness perception did not change during the trial. There were three deaths, but none was related to the intervention. Most adverse events were expected and related to the psychiatric illness. The process evaluation showed that the intervention was acceptable, with participants valuing the opportunity to interact with others facing similar challenges. Session feedback indicated that 87.2% of participants agreed that the sessions had met their needs. Some indicated the desire for more ongoing support. Professionals felt that the intervention was under-resourced and questioned the long-term sustainability within current NHS settings. Professionals would have preferred greater access to participants' behaviour data to tailor the intervention better. The incremental cost-effectiveness ratio from the health-care perspective is £246,921 per quality-adjusted life-year (QALY) gained and the incremental cost-effectiveness ratio from the societal perspective is £367,543 per QALY gained. CONCLUSIONS: Despite the challenges of undertaking clinical research in this population, the trial successfully recruited and retained participants, indicating a high level of interest in weight management interventions; however, the STEPWISE intervention was neither clinically effective nor cost-effective. Further research will be required to define how overweight and obesity in people with schizophrenia should be managed. The trial results suggest that lifestyle programmes for people with schizophrenia may need greater resourcing than for other populations, and interventions that have been shown to be effective in other populations, such as people with diabetes mellitus, are not necessarily effective in people with schizophrenia. TRIAL REGISTRATION: Current Controlled Trials ISRCTN19447796. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 22, No. 65. See the NIHR Journals Library website for further project information

    Serum magnesium and calcium levels in relation to ischemic stroke : Mendelian randomization study

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    ObjectiveTo determine whether serum magnesium and calcium concentrations are causally associated with ischemic stroke or any of its subtypes using the mendelian randomization approach.MethodsAnalyses were conducted using summary statistics data for 13 single-nucleotide polymorphisms robustly associated with serum magnesium (n = 6) or serum calcium (n = 7) concentrations. The corresponding data for ischemic stroke were obtained from the MEGASTROKE consortium (34,217 cases and 404,630 noncases).ResultsIn standard mendelian randomization analysis, the odds ratios for each 0.1 mmol/L (about 1 SD) increase in genetically predicted serum magnesium concentrations were 0.78 (95% confidence interval [CI] 0.69-0.89; p = 1.3 7 10-4) for all ischemic stroke, 0.63 (95% CI 0.50-0.80; p = 1.6 7 10-4) for cardioembolic stroke, and 0.60 (95% CI 0.44-0.82; p = 0.001) for large artery stroke; there was no association with small vessel stroke (odds ratio 0.90, 95% CI 0.67-1.20; p = 0.46). Only the association with cardioembolic stroke was robust in sensitivity analyses. There was no association of genetically predicted serum calcium concentrations with all ischemic stroke (per 0.5 mg/dL [about 1 SD] increase in serum calcium: odds ratio 1.03, 95% CI 0.88-1.21) or with any subtype.ConclusionsThis study found that genetically higher serum magnesium concentrations are associated with a reduced risk of cardioembolic stroke but found no significant association of genetically higher serum calcium concentrations with any ischemic stroke subtype

    X-ray observations of low-power radio galaxies from the B2 catalogue

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    The definitive version is available at www.blackwell-synergy.com. Copyright Blackwell Publishing DOI : 10.1046/j.1365-8711.1999.02923.xWe present an analysis of X-ray data, taken with ROSAT, for a well defined sample of low-power radio galaxies from the Bologna B2 catalogue. Where possible, the HRI has been used in order to take advantage of the higher spatial resolution provided by this instrument. A variety of models are fitted to radial profiles in order to separate the resolved and unresolved X-ray emission from the galaxies. We demonstrate a strong, approximately linear, correlation between the luminosities of the unresolved X-ray components and the 5-GHz luminosities of the radio cores in this sample. This suggests a physical relationship between the soft X-ray emission of radio galaxies and the jet- generated radio core emission. We infer a nuclear jet-related origin for at least some of the X-ray emission.Peer reviewe

    The behaviour of composite sandwich beams and panels under low velocity impact conditions

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    SIGLEAvailable from British Library Document Supply Centre- DSC:DX175644 / BLDSC - British Library Document Supply CentreGBUnited Kingdo
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