467 research outputs found

    Improving the measurement of QALYs in dementia: Developing patient- and carer-reported health state classification systems using Rasch analysis

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    Objectives: Cost-utility analysis is increasingly used to inform resource allocation. This requires a means of valuing health states before and after intervention. Although generic measures are typically used to generate values, these do not perform well with people with dementia. We report the development of a health state classification system amenable to valuation for use in studies of dementia, derived from the DEMQOL system, a measure of health-related quality of life in dementia by patient self-report (DEMQOL) and carer proxy-report (DEMQOL-Proxy). Methods: Factor analysis was used to determine the dimensional structure of DEMQOL and DEMQOL-Proxy. Rasch analysis was subsequently used to investigate item performance across factors in terms of item-level ordering, functioning across subgroups, model fit and severity-range coverage. This enabled the selection of one item from each factor for the classification system. A sample of people with a diagnosis of mild/moderate dementia (n=644) and a sample of carers of those with mild/moderate dementia (n=683) were used. Results: Factor analysis found different 5-factor solutions for DEMQOL and DEMQOL-Proxy. Following item reduction and selection using Rasch analysis, a 5-dimension classification for DEMQOL and a 4-dimension classification for DEMQOL-Proxy were developed. Each item contained 4 health state levels. Conclusion: Combining Rasch and classical psychometric analysis is a valid method of selecting items for dementia health state classifications from both the patient and carer perspectives. The next stage is to obtain preference weights so that the measure can be used in the economic evaluation of treatment, care and support arrangements for dementia

    The principles and practices of educational neuroscience: commentary on Bowers (2016)

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    In his recent critique of Educational Neuroscience, Bowers argues that neuroscience has no role to play in informing education, which he equates with classroom teaching. Neuroscience, he suggests, adds nothing to what we can learn from psychology. In this commentary, we argue that Bowers’ assertions misrepresent the nature and aims of the work in this new field. We suggest that, by contrast, psychological and neural levels of explanation complement rather than compete with each other. Bowers’ analysis also fails to include a role for educational expertise – a guiding principle of our new field. On this basis, we conclude that his critique is potentially misleading. We set out the well-documented goals of research in Educational Neuroscience, and show how, in collaboration with educators, significant progress has already been achieved, with the prospect of even greater progress in the future

    Intervention for children with word-finding difficulties: a parallel group randomised control trial

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    Purpose: The study investigated the outcome of a word-web intervention for children diagnosed with word-finding difficulties (WFDs). Method: Twenty children age 6–8 years with WFDs confirmed by a discrepancy between comprehension and production on the Test of Word Finding-2, were randomly assigned to intervention (n = 11) and waiting control (n = 9) groups. The intervention group had six sessions of intervention which used word-webs and targeted children’s meta-cognitive awareness and word-retrieval. Result: On the treated experimental set (n = 25 items) the intervention group gained on average four times as many items as the waiting control group (d = 2.30). There were also gains on personally chosen items for the intervention group. There was little change on untreated items for either group. Conclusion: The study is the first randomised control trial to demonstrate an effect of word-finding therapy with children with language difficulties in mainstream school. The improvement in word-finding for treated items was obtained following a clinically realistic intervention in terms of approach, intensity and duration

    Partial derivative automata formalized in Coq

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    In this paper we present a computer assisted proof of the correctness of a partial derivative automata construction from a regular expression within the Coq proof assistant. This proof is part of a for- malization of Kleene algebra and regular languages in Coq towards their usage in program certification.Fundação para a Ciência e Tecnologia (FCT) Program POSI, RESCUE (PTDC/EIA/65862/2006), SFRH/BD/33233/2007

    Evaluation of multi-season convection-permitting atmosphere – mixed-layer ocean simulations of the Maritime Continent

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    A multi-season convection-permitting regional climate simulation of the Maritime Continent (MC) using the Met Office Unified Model (MetUM) with 2.2 km grid spacing is presented and evaluated. The simulations pioneer the use of atmosphere–ocean coupling with the multi-column K profile parametrisation (KPP) mixed-layer ocean model in atmospheric convection-permitting climate simulations. Comparisons are made against a convection-parametrised simulation in which it is nested and which in turn derives boundary conditions from the ERA5 reanalysis. This paper describes the configuration, performance of the mean state and variability in the two simulations compared against observational datasets. The models have both minor sea surface temperature (SST) and wet precipitation biases. The diurnal cycle, representation of equatorial waves, and relationship between SST and precipitation are all improved in the convection-permitting model compared to the convection-parametrised model. The Madden–Julian oscillation (MJO) is present in both models with a faster-than-observed propagation speed. However, it is unclear whether fidelity of the MJO simulation is inherent to the model or whether it predominantly arises from the forcing at the boundaries

    The interplay of type I and type II interferons in murine autoimmune cholangitis as a basis for sex-biased autoimmunity

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    We have reported on a murine model of autoimmune cholangitis, generated by altering the AU-rich element (ARE) by deletion of the interferon gamma (IFN-γ) 3\u27 untranslated region (coined ARE-Del−/−), that has striking similarities to human primary biliary cholangitis (PBC) with female predominance. Previously, we suggested that the sex bias of autoimmune cholangitis was secondary to intense and sustained type I and II IFN signaling. Based on this thesis, and to define the mechanisms that lead to portal inflammation, we specifically addressed the hypothesis that type I IFNs are the driver of this disease. To accomplish these goals, we crossed ARE-Del−/− mice with IFN type I receptor alpha chain (Ifnar1) knockout mice. We report herein that loss of type I IFN receptor signaling in the double construct of ARE-Del−/− Ifnar1−/− mice dramatically reduces liver pathology and abrogated sex bias. More importantly, female ARE-Del−/− mice have an increased number of germinal center (GC) B cells as well as abnormal follicular formation, sites which have been implicated in loss of tolerance. Deletion of type I IFN signaling in ARE-Del−/− Ifnar1−/− mice corrects these GC abnormalities, including abnormal follicular structure. Conclusion: Our data implicate type I IFN signaling as a necessary component of the sex bias of this murine model of autoimmune cholangitis. Importantly these data suggest that drugs that target the type I IFN signaling pathway would have potential benefit in the earlier stages of PBC. (Hepatology 2018;67:1408-1419)

    Perception of Relative Depth Interval: Systematic Biases in Perceived Depth

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    Given an estimate of the binocular disparity between a pair of points and an estimate of the viewing distance, or knowledge of eye position, it should be possible to obtain an estimate of their depth separation. Here we show that, when points are arranged in different vertical geometric configurations across two intervals, many observers find this task difficult. Those who can do the task tend to perceive the depth interval in one configuration as very different from depth in the other configuration. We explore two plausible explanations for this effect. The first is the tilt of the empirical vertical horopter: Points perceived along an apparently vertical line correspond to a physical line of points tilted backwards in space. Second, the eyes can rotate in response to a particular stimulus. Without compensation for this rotation, biases in depth perception would result. We measured cyclovergence indirectly, using a standard psychophysical task, while observers viewed our depth configuration. Biases predicted from error due either to cyclovergence or to the tilted vertical horopter were not consistent with the depth configuration results. Our data suggest that, even for the simplest scenes, we do not have ready access to metric depth from binocular disparity.</jats:p

    Unveiling the structural transitions during activation of a CO2 methanation catalyst Ru0/ZrO2 synthesised from a MOF precursor

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    Available online 5 May 2020Carbon Capture, Utilisation and Storage (CCUS) technologies are utilised to minimise net CO2 emissions and hence mitigate the impact of anthropogenic emissions on the global climate. One example of CO2 utilisation is the production of carbon-neutral methane fuel via catalytic CO2 reduction with H2 (methanation). Thermal activation of a metal impregnated metal-organic framework (MOF), 1 wt%Ru/UiO-66 in the presence of H2 and CO2 provides in situ synthesis of a highly active methanation catalyst: H2 promotes the formation of Ru0 nanoparticles, and CO2 behaves as a mild oxidant to remove framework carbon and promote ZrO2 crystallisation. The nature of the active MOF-derived Ru0/ZrO2 catalyst was studied by PXRD, TEM, and XAS, and the evolution of the parent 1 wt%Ru/UiO-66 during thermal activation monitored in operando by synchrotron PXRD. The Ru impregnated Zr-based MOF collapses on heating in H2 and CO2 to form an amorphous C and Zr containing phase that subsequently crystallises as tetragonal (t-) ZrO2 nanoparticles. These t-ZrO2 nanoparticles undergo a subsequent phase transition to the more stable monoclinic (m-) ZrO2 polymorph. In situ activation of Ru/UiO-66 generates a highly active catalyst for CO2 methanation by transforming the MOF precursor into a (carbonfree) crystalline t-ZrO2 support that stabilises highly dispersed metallic Ru nanoparticles. This insight may guide the rational design of future MOF-derived catalystsRenata Lippi, Anita M. D, Angelo, Chaoen Li, Shaun C. Howard, Ian C. Madsen, Karen Wilson, Adam F. Lee, Christopher J. Sumby, Christian J. Doonan, Jim Patel, Danielle F. Kenned

    Red Queen Coevolution on Fitness Landscapes

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    Species do not merely evolve, they also coevolve with other organisms. Coevolution is a major force driving interacting species to continuously evolve ex- ploring their fitness landscapes. Coevolution involves the coupling of species fit- ness landscapes, linking species genetic changes with their inter-specific ecological interactions. Here we first introduce the Red Queen hypothesis of evolution com- menting on some theoretical aspects and empirical evidences. As an introduction to the fitness landscape concept, we review key issues on evolution on simple and rugged fitness landscapes. Then we present key modeling examples of coevolution on different fitness landscapes at different scales, from RNA viruses to complex ecosystems and macroevolution.Comment: 40 pages, 12 figures. To appear in "Recent Advances in the Theory and Application of Fitness Landscapes" (H. Richter and A. Engelbrecht, eds.). Springer Series in Emergence, Complexity, and Computation, 201
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