1,747 research outputs found

    A randomised trial of an internet weight control resource: The UK Weight Control Trial [ISRCTN58621669]

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    BACKGROUND: Obesity treatment is notoriously unsuccessful and one of the barriers to successful weight loss reported by patients is a lack of social support. The Internet offers a novel and fast approach to the delivery of health information, enabling 24-hour access to help and advice. However, much of the health information available on the Internet is unregulated or not written by qualified health professionals to provide unbiased information. The proposed study aims to compare a web-based weight loss package with traditional dietary treatment of obesity in participants. The project aims to deliver high quality information to the patient and to evaluate the effectiveness of this information, both in terms of weight loss outcomes and cost-effectiveness. METHODS: This study is a randomised controlled trial of a weight loss package against usual care provided within General Practice (GP) surgeries in Leeds, UK. Participants will be recruited via posters placed in participating practices. A target recruitment figure of 220 will enable 180 people to be recruited (allowing for 22% dropout). Participants agreeing to take part in the study will be randomly allocated using minimisation to either the intervention group, receiving access to the Internet site, or the usual care group. The primary outcome of the study will be the ability of the package to promote change in BMI over 6 and 12 months compared with traditional treatment. Secondary outcomes will be the ability of the Internet package to promote change in reported lifestyle behaviours. Data will be collected on participant preferences, adherence to treatment, health care use and time off work. Difference in cost between groups in provision of the intervention and the cost of the primary outcome will also be estimated. CONCLUSION: A positive result from this study would enhance the repertoire of treatment approaches available for the management of obesity. A negative result would be used to inform the research agenda and contribute to redefining future strategies for tackling obesity

    Extreme enriched and heterogeneous ⁸⁷Sr/⁸⁶Sr ratios recorded in magmatic plagioclase from the Samoan hotspot

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    We report the major-element, trace-element, and 87Sr/86Sr compositions of six plagioclase crystals from two Samoan lavas with extreme EM2 isotopic compositions (ALIA-115-18 with whole-rock 87Sr/86Sr of 0.718592, and ALIA-115-21 with whole-rock 87Sr/86Sr of 0.720469). We employed laser-ablation split-stream mass spectrometry (LASS) to simultaneously measure 87Sr/86Sr ratios, major-element concentrations, and trace-element concentrations in the same plagioclase crystal volume. We find that two plagioclase crystals have extreme 87Sr/86Sr heterogeneity in excess of 5000 ppm (where ppm of 87Sr/Sr variability86=106⋅[Sr/8687Srmax−87Sr/86Srmin]/87Sr/86Sravg). In two of the plagioclase crystals, we identify the highest 87Sr/86Sr ratios (0.7224) ever measured in any fresh, mantle-derived ocean island basalt (OIB) or OIB-hosted mineral phase.We find that in 87Sr/86Sr-versus-Sr concentration space, the six plagioclase crystals overlap in a “common component” region with higher 87Sr/86Sr than has been previously identified in whole-rock Samoan lavas or mineral separates. We use the occurrence of olivine mineral inclusions (Fo=74.5±0.8, 2 SD) in the high-87Sr/86Sr zone of one plagioclase crystal to infer the bulk composition (Mg#=46.8±0.8, 2 SD) of the extreme EM2 magma from which the olivine and high-87Sr/86Sr plagioclase crystallized. We argue that a relatively evolved EM2 endmember magma mixed with at least one lower-87Sr/86Sr melt to generate the observed intra-crystal plagioclase isotopic heterogeneity.By inferring that subducted terrigenous sediment gives rise to EM2 signatures in Samoan lavas, we estimate that the quantity of sediment necessary to generate the most-elevated 87Sr/86Sr ratios observed in the Samoan plagioclase is ∼7% of the mantle source. We also estimate that sediment subduction into the mantle over geologic time has generated a sediment domain that constitutes 0.02% of the mass of the mantle, a much lower proportion than required in the EM2 mantle source. Even if subducted sediment is concentrated in large low-shear-velocity provinces (LLSVPs) at the base of the mantle (which constitute up to 7.7% of the mantle's mass), then only 0.25% of the LLSVPs are composed of sediment. This requires that the distribution of subducted sediment in the mantle is heterogeneous, and the high relative abundance of sediment in the Samoan EM2 mantle is an anomalous relic of ancient subduction that has survived convective attenuation

    A multicentre, randomised controlled trial comparing the clinical effectiveness and cost-effectiveness of early nutritional support via the parenteral versus the enteral route in critically ill patients (CALORIES)

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    BACKGROUND: Malnutrition is a common problem in critically ill patients in UK NHS critical care units. Early nutritional support is therefore recommended to address deficiencies in nutritional state and related disorders in metabolism. However, evidence is conflicting regarding the optimum route (parenteral or enteral) of delivery. OBJECTIVES: To estimate the effect of early nutritional support via the parenteral route compared with the enteral route on mortality at 30 days and on incremental cost-effectiveness at 1 year. Secondary objectives were to compare the route of early nutritional support on duration of organ support; infectious and non-infectious complications; critical care unit and acute hospital length of stay; all-cause mortality at critical care unit and acute hospital discharge, at 90 days and 1 year; survival to 90 days and 1 year; nutritional and health-related quality of life, resource use and costs at 90 days and 1 year; and estimated lifetime incremental cost-effectiveness. DESIGN: A pragmatic, open, multicentre, parallel-group randomised controlled trial with an integrated economic evaluation. SETTING: Adult general critical care units in 33 NHS hospitals in England. PARTICIPANTS: 2400 eligible patients. INTERVENTIONS: Five days of early nutritional support delivered via the parenteral (n = 1200) and enteral (n = 1200) route. MAIN OUTCOME MEASURES: All-cause mortality at 30 days after randomisation and incremental net benefit (INB) (at £20,000 per quality-adjusted life-year) at 1 year. RESULTS: By 30 days, 393 of 1188 (33.1%) patients assigned to receive early nutritional support via the parenteral route and 409 of 1195 (34.2%) assigned to the enteral route had died [p = 0.57; absolute risk reduction 1.15%, 95% confidence interval (CI) -2.65 to 4.94; relative risk 0.97 (0.86 to 1.08)]. At 1 year, INB for the parenteral route compared with the enteral route was negative at -£1320 (95% CI -£3709 to £1069). The probability that early nutritional support via the parenteral route is more cost-effective - given the data - is < 20%. The proportion of patients in the parenteral group who experienced episodes of hypoglycaemia (p = 0.006) and of vomiting (p < 0.001) was significantly lower than in the enteral group. There were no significant differences in the 15 other secondary outcomes and no significant interactions with pre-specified subgroups. LIMITATIONS: Blinding of nutritional support was deemed to be impractical and, although the primary outcome was objective, some secondary outcomes, although defined and objectively assessed, may have been more vulnerable to observer bias. CONCLUSIONS: There was no significant difference in all-cause mortality at 30 days for early nutritional support via the parenteral route compared with the enteral route among adults admitted to critical care units in England. On average, costs were higher for the parenteral route, which, combined with similar survival and quality of life, resulted in negative INBs at 1 year. FUTURE WORK: Nutritional support is a complex combination of timing, dose, duration, delivery and type, all of which may affect outcomes and costs. Conflicting evidence remains regarding optimum provision to critically ill patients. There is a need to utilise rigorous consensus methods to establish future priorities for basic and clinical research in this area. TRIAL REGISTRATION: Current Controlled Trials ISRCTN17386141. FUNDING: This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 20, No. 28. See the NIHR Journals Library website for further project information

    Evaluating the successful implementation of evidence into practice using the PARiHS framework : theoretical and practical challenges

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    Background The PARiHS framework (Promoting Action on Research Implementation in Health Services) has proved to be a useful practical and conceptual heuristic for many researchers and practitioners in framing their research or knowledge translation endeavours. However, as a conceptual framework it still remains untested and therefore its contribution to the overall development and testing of theory in the field of implementation science is largely unquantified. Discussion This being the case, the paper provides an integrated summary of our conceptual and theoretical thinking so far and introduces a typology (derived from social policy analysis) used to distinguish between the terms conceptual framework, theory and model – important definitional and conceptual issues in trying to refine theoretical and methodological approaches to knowledge translation. Secondly, the paper describes the next phase of our work, in particular concentrating on the conceptual thinking and mapping that has led to the generation of the hypothesis that the PARiHS framework is best utilised as a two-stage process: as a preliminary (diagnostic and evaluative) measure of the elements and sub-elements of evidence (E) and context (C), and then using the aggregated data from these measures to determine the most appropriate facilitation method. The exact nature of the intervention is thus determined by the specific actors in the specific context at a specific time and place. In the process of refining this next phase of our work, we have had to consider the wider issues around the use of theories to inform and shape our research activity; the ongoing challenges of developing robust and sensitive measures; facilitation as an intervention for getting research into practice; and finally to note how the current debates around evidence into practice are adopting wider notions that fit innovations more generally. Summary The paper concludes by suggesting that the future direction of the work on the PARiHS framework is to develop a two-stage diagnostic and evaluative approach, where the intervention is shaped and moulded by the information gathered about the specific situation and from participating stakeholders. In order to expedite the generation of new evidence and testing of emerging theories, we suggest the formation of an international research implementation science collaborative that can systematically collect and analyse experiences of using and testing the PARiHS framework and similar conceptual and theoretical approaches. We also recommend further refinement of the definitions around conceptual framework, theory, and model, suggesting a wider discussion that embraces multiple epistemological and ontological perspectives

    Dissociable effects of 5-HT2C receptor antagonism and genetic inactivation on perseverance and learned non-reward in an egocentric spatial reversal task

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    Cognitive flexibility can be assessed in reversal learning tests, which are sensitive to modulation of 5-HT2C receptor (5-HT2CR) function. Successful performance in these tests depends on at least two dissociable cognitive mechanisms which may separately dissipate associations of previous positive and negative valence. The first is opposed by perseverance and the second by learned non-reward. The current experiments explored the effect of reducing function of the 5-HT2CR on the cognitive mechanisms underlying egocentric reversal learning in the mouse. Experiment 1 used the 5-HT2CR antagonist SB242084 (0.5 mg/kg) in a between-groups serial design and Experiment 2 used 5-HT2CR KO mice in a repeated measures design. Animals initially learned to discriminate between two egocentric turning directions, only one of which was food rewarded (denoted CS+, CS−), in a T- or Y-maze configuration. This was followed by three conditions; (1) Full reversal, where contingencies reversed; (2) Perseverance, where the previous CS+ became CS− and the previous CS− was replaced by a novel CS+; (3) Learned non-reward, where the previous CS− became CS+ and the previous CS+ was replaced by a novel CS-. SB242084 reduced perseverance, observed as a decrease in trials and incorrect responses to criterion, but increased learned non-reward, observed as an increase in trials to criterion. In contrast, 5-HT2CR KO mice showed increased perseverance. 5-HT2CR KO mice also showed retarded egocentric discrimination learning. Neither manipulation of 5-HT2CR function affected performance in the full reversal test. These results are unlikely to be accounted for by increased novelty attraction, as SB242084 failed to affect performance in an unrewarded novelty task. In conclusion, acute 5-HT2CR antagonism and constitutive loss of the 5-HT2CR have opposing effects on perseverance in egocentric reversal learning in mice. It is likely that this difference reflects the broader impact of 5HT2CR loss on the development and maintenance of cognitive function

    The remnants of galaxy formation from a panoramic survey of the region around M31

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    In hierarchical cosmological models, galaxies grow in mass through the continual accretion of smaller ones. The tidal disruption of these systems is expected to result in loosely bound stars surrounding the galaxy, at distances that reach 1010010 - 100 times the radius of the central disk. The number, luminosity and morphology of the relics of this process provide significant clues to galaxy formation history, but obtaining a comprehensive survey of these components is difficult because of their intrinsic faintness and vast extent. Here we report a panoramic survey of the Andromeda galaxy (M31). We detect stars and coherent structures that are almost certainly remnants of dwarf galaxies destroyed by the tidal field of M31. An improved census of their surviving counterparts implies that three-quarters of M31's satellites brighter than MV<6M_V < -6 await discovery. The brightest companion, Triangulum (M33), is surrounded by a stellar structure that provides persuasive evidence for a recent encounter with M31. This panorama of galaxy structure directly confirms the basic tenets of the hierarchical galaxy formation model and reveals the shared history of M31 and M33 in the unceasing build-up of galaxies.Comment: Published in Nature. Supplementary movie available at https://www.astrosci.ca/users/alan/PANDAS/Latest%20news%3A%20movie%20of%20orbit.htm

    The Political Economy of Non-Traditional Security: Explaining the Governance of Avian Influenza in Indonesia

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    Given the common association of non-traditional security (NTS) problems with globalisation, surprisingly little attention has been paid to how the political economy context of given NTS issues shape how they are securitised and managed in practice. We argue that security and its governance are always highly contested because different modes of security governance invariably privilege particular interests and normative agendas in state and society, which relate directly to the political economy. Drawing on critical political geography, we argue that, because NTS issues are perceived as at least potentially transnational, their securitisation often involves strategic attempts by actors and coalitions to ‘rescale’ their governance beyond the national political and institutional arenas, into new, expert-dominated modes of governance. Such efforts are often resisted by other coalitions, for which this rescaling is deleterious. As evidenced by a case study of avian influenza in Indonesia, particular governance outcomes depend upon the nature of the coalitions assembled for and against rescaling in specific situations, while these coalitions’ make-up and relative strength is shaped by the political economy of the industries that rescaling would affect, viewed against the broader backdrop of state-society relations
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