586 research outputs found

    Clusters of Galaxies: New Results from the CLEF Hydrodynamics Simulation

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    Preliminary results are presented from the CLEF hydrodynamics simulation, a large (N=2(428)^3 particles within a 200 Mpc/h comoving box) simulation of the LCDM cosmology that includes both radiative cooling and a simple model for galactic feedback. Specifically, we focus on the X-ray properties of the simulated clusters at z=0 and demonstrate a reasonable level of agreement between simulated and observed cluster scaling relations.Comment: 7 pages, 4 figures, accepted for publication in Advances in Space Research (proceedings of the COSPAR 2004 Assembly, Paris

    Use of very high resolution climate model data for hydrological modelling: baseline performance and future flood changes

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    Increasingly, data from Regional Climate Models (RCMs) are used to drive hydrological models, to investigate the potential water-related impacts of climate change, particularly for flood and droughts. Generally, some form of further downscaling of RCM data has been required, but recently the first decadal-length runs of very high resolution RCMs (with convection-permitting scales) have been performed. Here, a set of such runs for southern Britain has been used to drive a gridded hydrological model. Results using a 1.5km RCM nested in a 12km RCM driven by European-reanalysis boundary conditions show that the 1.5km RCM generally performs worse than the 12km RCM for simulating river flows in 32 example catchments. The clear spatial patterns of bias are consistent with bias patterns shown in the RCM precipitation data. Results using 1.5km and 12km RCM runs for the current climate and a potential future climate (driven by GCM boundary conditions) show clear differences in projected changes in flood peaks. The 1.5km RCM tends towards larger increases than the 12km RCM, particularly in spring and winter. If robust, this could have important consequences for adaptation planning under climate change, but further research is required, particularly given the greater biases in the baseline flow simulations driven by 1.5km RCM data, and the use of only a single short future climate projection

    Culture modifies the operation of prime-to-behavior effects

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    Culture affects the extent to which people focus on other people or on the situation in drawing inferences. Building on recent research showing that perceptions of others and situations can mediate prime-to-behavior effects, we tested whether culture would modify both the mechanism and the outcome of primed constructs on behavior. Easterners and Westerners were primed with competitiveness or cooperativeness before playing a social dilemma game with an ambiguously or unambiguously competitive player. Results indicated that the primes had different effects on the social dilemma decisions of Easterners and Westerners and that these effects were due to the different consequences the primes had for Easterners’ and Westerners’ perceptions of the other player and construals of the situation

    Framework for setting up a Hydro-JULES perturbed parameter ensemble (PPE)

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    Land surface and hydrological processes and feedbacks that act at sub-grid scales need to be parameterised within models. These parameterisation schemes are an important source of uncertainty in model simulations. One of the aims of Hydro- JULES (HJ) is to quantify uncertainties in river flows induced by land surface and hydrological model parameterisations

    National-scale analysis of low flow frequency: historical trends and potential future changes

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    The potential impact of climate change on hydrological extremes is of increasing concern across the globe. Here, a national-scale grid-based hydrological model is used to investigate historical trends and potential future changes in low flow frequency across Great Britain. The historical analyses use both observational data (1891–2015) and ensemble data from a regional climate model (1900–2006). The results show relatively few significant trends in historical low flows (2- or 20-year return period), whether based on 7- or 30-day annual minima. Significant negative trends seen in some limited parts of the country when using observational data are generally not seen when using climate model data. The future analyses use climate model ensemble data for both near future and far future time periods (2020–2049 and 2070–2099 respectively), which are compared to a baseline sub-period from the historical ensemble (1975–2004). The results show future reductions in low flows, which are generally larger in the south of the country, at the higher (20-year) return period, and for the later time period. Reductions are more limited if the estimates of future potential evaporation include the effect of increased carbon dioxide concentrations on stomatal resistance. Such reductions in river flow could have significant impacts on the aquatic environment and on agriculture, and present a challenge for water managers, especially as reductions in water supply are likely to occur alongside increases in demand

    Climate change impacts on peak river flows: combining national-scale hydrological modelling and probabilistic projections

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    Potential future increases in flooding due to climate change need to be taken into consideration when designing flood defences or planning new infrastructure or housing developments. Existing guidance on climate change allowances in Great Britain was based on research that developed a sensitivity-based approach to estimating the impacts of climate change on flood peaks, which was applied with catchment-based hydrological models. Here, the sensitivity-based approach is applied with a national-scale grid-based hydrological model, producing modelled flood response surfaces for every river cell on a 1km grid. This provides a nationally consistent assessment of the sensitivity of flood peaks across Britain to climatic changes. The flood response surfaces are then combined with the most recent climate change projections, UK Climate Projections 2018 (UKCP18), to provide location-specific information on the potential range of impacts on floods across the country, for three flood return periods, three future time-slices and four emissions scenarios. An accompanying web-tool provides a convenient way to explore the large amount of data produced. Consideration is now being given to how to use the latest work to update guidance on climate change and flood peaks, including a workshop held to gather stakeholder views

    CCRA3 flooding projections, task 2a: high resolution climate change projections — fluvial. Technical note

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    As part of the CCRA3 flooding projections project, this task provides: 1. estimates of percentage changes in flood peaks for locations across the UK, using UKCP18 probabilistic projections applied for a set of global mean surface temperature (GMST) changes (ranging from 1.0°C to 4.5°C in increments of 0.5°C); and 2. estimates of change in return period corresponding to a range of peak flow uplifts, as look-up tables, for locations across the UK. The data are provided for use within the Future Flood Explorer (FFE) to investigate potential future flood risks under climate change, under a range of adaptation options. This technical report details the methodology used to produce the flood peak and return period data, including differences in the methods used for Great Britain and Nothern Ireland

    Evaluacija inovativno digitalno kontroliranog Er:YAG lasera u lijeÄŤenju leukoplakije - probno istraĹľivanje

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    The use of lasers for treatment of oral leukoplakia has gained a lot of interest in the past years, however, data on the use of Er:YAG laser are scarce. The aim of this study was to compare the efficacy of Er:YAG laser and 1% topical isotretinoin in the treatment of 27 oral leukoplakia patients. Er:YAG laser (LightWalker AT, Fotona, Slovenia) was used in 27 patients with 27 leukoplakia lesions. Postoperative pain was assessed by use of visual analog scale (VAS), and the impact of laser treatment on the quality of life was assessed by the OHIP-14 questionnaire (Croatian version). Control group consisted of the same 27 patients previously treated with 1% topical isotretionin three times a day during the period of one year. No improvement in the size of leukoplakia lesions was observed after treatment with topical isotretinoin. There were significant differences between men and women according to leukoplakia localization, number of laser sessions and VAS (p<0.05). At follow-up after six months and one year, there was no recurrence of lesions. Er:YAG laser is a successful treatment for oral leukoplakia. Topical isotretionin treatment is unsuccessful in patients with oral leukoplakia.Posljednjih godina postoji veliko zanimanje za upotrebu lasera u liječenju oralne leukoplakije, ali su podatci o upotrebi Er:YAG lasera malobrojni. Cilj ovoga istraživanja bio je usporediti učinak Er:YAG lasera i 1%-tnog topikalnog izotretinoina u liječenju 27 bolesnika s oralnom leukoplakijom. Er:YAG laser (LightWalker AT, Fotona, Slovenia) je korišten u 27 bolesnika s 27 leukoplakičnih lezija. Poslijeoperacijska bol je određena uz pomoć vizualne analogne ljestvice (visual analog scale, VAS), a utjecaj na kvalitetu života mjeren je pomoću upitnika OHIP-14 (hrvatska verzija). Kontrolna skupina se sastojala od istih 27 bolesnika koji su prije toga liječeni 1%-tnim topikalnim izotretioninom tri puta na dan tijekom tri mjeseca. Nije bilo poboljšanja u veličini lezija leukoplakije nakon topikalno primijenjenog izotretinoina. Utvrđene su značajne razlike između muškaraca i žena s obzirom na lokalizaciju leukoplakije, broj laserskih zahvata i rezultata VAS (p<0,05). Šest mjeseci i godinu dana od laserskog zahvata nije bilo recidiva oralne leukoplakije. Er:YAG laser je uspješna terapija u liječenju oralne leukoplakije. Topikalna primjena izotretionina nije uspješna u liječenju oralne leukoplakije

    An intervention study to prevent relapse in patients with schizophrenia

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    Purpose: To determine whether the use of relapse prevention plans (RPPs) in nursing practice is an effective intervention in reducing relapse rates among patients with schizophrenia. Design and Methods: Experimental design. Patients with schizophrenia (or a related psychotic disorder) and nurses from three mental health organizations were randomly assigned to either an experimental (RPP) or control condition (care as usual). The primary outcome measure was the psychotic relapses in the research groups. Results: The relapse rates in the experimental and control groups after 1-year follow-up were 12.5% and 26.2%, respectively (p=.12, ns). The relative risk of a relapse in the experimental versus the control group was 0.48(ns). Conclusions: In this study no statistically significant effects of the intervention were found. Effectiveness research in this area should be continued with larger sample sizes and longer follow-up periods

    Some general properties of the renormalized stress-energy tensor for static quantum states on (n+1)-dimensional spherically symmetric black holes

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    We study the renormalized stress-energy tensor (RSET) for static quantum states on (n+1)-dimensional, static, spherically symmetric black holes. By solving the conservation equations, we are able to write the stress-energy tensor in terms of a single unknown function of the radial co-ordinate, plus two arbitrary constants. Conditions for the stress-energy tensor to be regular at event horizons (including the extremal and ``ultra-extremal'' cases) are then derived using generalized Kruskal-like co-ordinates. These results should be useful for future calculations of the RSET for static quantum states on spherically symmetric black hole geometries in any number of space-time dimensions.Comment: 9 pages, no figures, RevTeX4, references added, accepted for publication in General Relativity and Gravitatio
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