468 research outputs found

    Valuing condition specific health states using simulation contact lenses

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    OBJECTIVE: This paper reports on a study that used contact lenses to simulate the effects of a visual impairment caused by Age Related Macular Degeneration (ARMD). The aim was to examine the feasibility of using this method of simulation and to compare the results from this experiment with those obtained from ARMD patients (n=209) using generic preference-based measures (HUI3 and EQ-5D) and patient time trade-off TTO. METHODS: Utility values were elicited from healthy participants (n=108) by TTO for three ARMD states simulated using contact lenses. RESULTS: A significant relationship was found between visual acuity and TTO values elicited from members of the general population (n=108). It was stronger than that found for HUI3, EQ-5D and own TTO values from patients (n=209). General population values informed by the experience of simulation were found to be significantly different to values from patient TTO and generic preference-based measures for the same level of visual impairment. Socio-demographic characteristics did not significantly affect results, although baseline TTO utility values were positively associated with TTO values for simulated states. CONCLUSIONS: ARMD has a major impact on general population TTO health state values. Differences across four visual health states appear larger than those found for a generic preference-based measures and patient TTO values. For conditions that are difficult to describe and imagine, simulation methods may offer an important method for obtaining better informed general population preferences

    Comment on: “Peatland carbon stocks and burn history: Blanket bog peat core evidence highlights charcoal impacts on peat physical properties and long-term carbon storage”, by A. Heinemeyer, Q. Asena, W.L. Burn and A.L. Jones (Geo: Geography and Environment. 2018; e00063)

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    A recent paper by Heinemeyer et al. (2018) in this journal has suggested that the use of prescribed fire may enhance carbon accumulation in UK upland blanket bogs. We challenge this finding based on a number of concerns with the original manuscript including the lack of an unburned control, insufficient replication, unrecognised potential confounding factors, and potentially large inaccuracies in the core dating approach used to calculate carbon accumulation rates. We argue that burn‐management of peatlands is more likely to lead to carbon loss than carbon gain

    Magnetic Field Amplification in Galaxy Clusters and its Simulation

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    We review the present theoretical and numerical understanding of magnetic field amplification in cosmic large-scale structure, on length scales of galaxy clusters and beyond. Structure formation drives compression and turbulence, which amplify tiny magnetic seed fields to the microGauss values that are observed in the intracluster medium. This process is intimately connected to the properties of turbulence and the microphysics of the intra-cluster medium. Additional roles are played by merger induced shocks that sweep through the intra-cluster medium and motions induced by sloshing cool cores. The accurate simulation of magnetic field amplification in clusters still poses a serious challenge for simulations of cosmological structure formation. We review the current literature on cosmological simulations that include magnetic fields and outline theoretical as well as numerical challenges.Comment: 60 pages, 19 Figure

    Exploring bodily sensations experienced during flow states in professional national hunt jockeys: a connecting analysis

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    Previous research has suggested that distinct bodily sensations are experienced by athletes during flow states, and could represent a sport-specific characteristic of this phenomenon. This study aimed to enrich understanding about bodily sensations and flow states in sport by exploring this experience in national hunt jockeys. The interspecies nature of horse-rider partnerships accentuates the importance of bodily awareness in equestrian sports. Therefore, horse racing provided a fertile context in which to investigate bodily sensations experienced during flow states in sport. In-depth, semi-structured interviews exploring the experience of flow in horse racing were undertaken with 10 professional national hunt jockeys (M age = 28.1 years). Data were interpreted iteratively using inductive categorising/thematic and connecting analyses. Present findings suggested that flow states in jockeys produce an idiosyncratic and multifaceted sensory experience, and indicated that altered physical perceptions during flow were not restricted to kinaesthetic properties. Jockeys explained that distinct bodily sensations were experienced during flow states, and described alterations in their perceptions of kinaesthetic ‘feel’, balance, arousal and strength of touch. Each of these bodily sensations was discussed in relation to sensory information received from the horse, and a connecting analysis enlightened the factors underlying the realisation of these unique bodily sensations that accompanied flow states. Findings are discussed with respect to the existing literature on flow in sport and recommendations for future research are outlined. Further, possible considerations regarding the inclusion of bodily sensations as a characteristic of the flow experience in sport are outlined

    A new strategy for enhancing imputation quality of rare variants from next-generation sequencing data via combining SNP and exome chip data

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    Background: Rare variants have gathered increasing attention as a possible alternative source of missing heritability. Since next generation sequencing technology is not yet cost-effective for large-scale genomic studies, a widely used alternative approach is imputation. However, the imputation approach may be limited by the low accuracy of the imputed rare variants. To improve imputation accuracy of rare variants, various approaches have been suggested, including increasing the sample size of the reference panel, using sequencing data from study-specific samples (i.e., specific populations), and using local reference panels by genotyping or sequencing a subset of study samples. While these approaches mainly utilize reference panels, imputation accuracy of rare variants can also be increased by using exome chips containing rare variants. The exome chip contains 250 K rare variants selected from the discovered variants of about 12,000 sequenced samples. If exome chip data are available for previously genotyped samples, the combined approach using a genotype panel of merged data, including exome chips and SNP chips, should increase the imputation accuracy of rare variants. Results: In this study, we describe a combined imputation which uses both exome chip and SNP chip data simultaneously as a genotype panel. The effectiveness and performance of the combined approach was demonstrated using a reference panel of 848 samples constructed using exome sequencing data from the T2D-GENES consortium and 5,349 sample genotype panels consisting of an exome chip and SNP chip. As a result, the combined approach increased imputation quality up to 11 %, and genomic coverage for rare variants up to 117.7 % (MAF < 1 %), compared to imputation using the SNP chip alone. Also, we investigated the systematic effect of reference panels on imputation quality using five reference panels and three genotype panels. The best performing approach was the combination of the study specific reference panel and the genotype panel of combined data. Conclusions: Our study demonstrates that combined datasets, including SNP chips and exome chips, enhances both the imputation quality and genomic coverage of rare variants
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