3,259 research outputs found

    The relative impact of baryons and cluster shape on weak lensing mass estimates of galaxy clusters

    Get PDF
    Weak gravitational lensing depends on the integrated mass along the line of sight. Baryons contribute to the mass distribution of galaxy clusters and the resulting mass estimates from lensing analysis. We use the cosmo-OWLS suite of hydrodynamic simulations to investigate the impact of baryonic processes on the bias and scatter of weak lensing mass estimates of clusters. These estimates are obtained by fitting NFW profiles to mock data using MCMC techniques. In particular, we examine the difference in estimates between dark matter-only runs and those including various prescriptions for baryonic physics. We find no significant difference in the mass bias when baryonic physics is included, though the overall mass estimates are suppressed when feedback from AGN is included. For lowest-mass systems for which a reliable mass can be obtained (M2002×1014M_{200} \approx 2 \times 10^{14} MM_{\odot}), we find a bias of 10\approx -10 per cent. The magnitude of the bias tends to decrease for higher mass clusters, consistent with no bias for the most massive clusters which have masses comparable to those found in the CLASH and HFF samples. For the lowest mass clusters, the mass bias is particularly sensitive to the fit radii and the limits placed on the concentration prior, rendering reliable mass estimates difficult. The scatter in mass estimates between the dark matter-only and the various baryonic runs is less than between different projections of individual clusters, highlighting the importance of triaxiality

    Implementation of routine outcome measurement in child and adolescent mental health services in the United Kingdom: a critical perspective

    Get PDF
    The aim of this commentary is to provide an overview of clinical outcome measures that are currently recommended for use in UK Child and Adolescent Mental Health Services (CAMHS), focusing on measures that are applicable across a wide range of conditions with established validity and reliability, or innovative in their design. We also provide an overview of the barriers and drivers to the use of Routine Outcome Measurement (ROM) in clinical practice

    Dark Force Detection in Low Energy e-p Collisions

    Get PDF
    We study the prospects for detecting a light boson X with mass m_X < 100 MeV at a low energy electron-proton collider. We focus on the case where X dominantly decays to e+ e- as motivated by recent "dark force" models. In order to evade direct and indirect constraints, X must have small couplings to the standard model (alpha_X 10 MeV). By comparing the signal and background cross sections for the e- p e+ e- final state, we conclude that dark force detection requires an integrated luminosity of around 1 inverse attobarn, achievable with a forthcoming JLab proposal.Comment: 38 pages, 19 figures; v2, references adde

    Caesarean Section among Referred and Self-Referred Birthing Women: A Cohort Study from a Tertiary Hospital, Northeastern Tanzania.

    Get PDF
    The inequity in emergency obstetric care access in Tanzania is unsatisfactory. Despite an existing national obstetric referral system, many birthing women bypass referring facilities and go directly to higher-level care centres. We wanted to compare Caesarean section (CS) rates among women formally referred to a tertiary care centre versus self-referred women, and to assess the effect of referral status on adverse outcomes after CS. We used data from 21,011 deliveries, drawn from the birth registry of a tertiary hospital in northeastern Tanzania, during 2000-07. Referral status was categorized as self-referred if the woman had bypassed or not accessed referral, or formally-referred if referred by a health worker. Because CS indications were insufficiently registered, we applied the Ten-Group Classification System to determine the CS rate by obstetric group and referral status. Associations between referral status and adverse outcomes after CS delivery were analysed using multiple regression models. Outcome measures were CS, maternal death, obstetric haemorrhage ≥ 750 mL, postpartum stay > 9 days, neonatal death, Apgar score < 7 at 5 min and neonatal ward transfer. Referral status contributed substantially to the CS rate, which was 55.0% in formally-referred and 26.9% in self-referred birthing women. In both groups, term nulliparous singleton cephalic pregnancies and women with previous scar(s) constituted two thirds of CS deliveries. Low Apgar score (adjusted OR 1.42, 95% CI 1.09-1.86) and neonatal ward transfer (adjusted OR 1.18, 95% CI 1.04-1.35) were significantly associated with formal referral. Early neonatal death rates after CS were 1.6% in babies of formally-referred versus 1.2% in babies of self-referred birthing women, a non-significant difference after adjusting for confounding factors (adjusted OR 1.37, 95% CI 0.87-2.16). Absolute neonatal death rates were > 2% after CS in breech, multiple gestation and preterm deliveries in both referral groups. Women referred for delivery had higher CS rates and poorer neonatal outcomes, suggesting that the formal referral system successfully identifies high-risk birth, although low volume suggests underutilization. High absolute rates of post-CS adverse outcomes among breech, multiple gestation and preterm deliveries suggest the need to target self-referred birthing women for earlier professional intrapartum care

    Garden and landscape-scale correlates of moths of differing conservation status: significant effects of urbanization and habitat diversity

    Get PDF
    Moths are abundant and ubiquitous in vegetated terrestrial environments and are pollinators, important herbivores of wild plants, and food for birds, bats and rodents. In recent years, many once abundant and widespread species have shown sharp declines that have been cited by some as indicative of a widespread insect biodiversity crisis. Likely causes of these declines include agricultural intensification, light pollution, climate change, and urbanization; however, the real underlying cause(s) is still open to conjecture. We used data collected from the citizen science Garden Moth Scheme (GMS) to explore the spatial association between the abundance of 195 widespread British species of moth, and garden habitat and landscape features, to see if spatial habitat and landscape associations varied for species of differing conservation status. We found that associations with habitat and landscape composition were species-specific, but that there were consistent trends in species richness and total moth abundance. Gardens with more diverse and extensive microhabitats were associated with higher species richness and moth abundance; gardens near to the coast were associated with higher richness and moth abundance; and gardens in more urbanized locations were associated with lower species richness and moth abundance. The same trends were also found for species classified as increasing, declining and vulnerable under IUCN (World Conservation Union) criteria

    Chronic non-specific low back pain - sub-groups or a single mechanism?

    Get PDF
    Copyright 2008 Wand and O'Connell; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Background: Low back pain is a substantial health problem and has subsequently attracted a considerable amount of research. Clinical trials evaluating the efficacy of a variety of interventions for chronic non-specific low back pain indicate limited effectiveness for most commonly applied interventions and approaches. Discussion: Many clinicians challenge the results of clinical trials as they feel that this lack of effectiveness is at odds with their clinical experience of managing patients with back pain. A common explanation for this discrepancy is the perceived heterogeneity of patients with chronic non-specific low back pain. It is felt that the effects of treatment may be diluted by the application of a single intervention to a complex, heterogeneous group with diverse treatment needs. This argument presupposes that current treatment is effective when applied to the correct patient. An alternative perspective is that the clinical trials are correct and current treatments have limited efficacy. Preoccupation with sub-grouping may stifle engagement with this view and it is important that the sub-grouping paradigm is closely examined. This paper argues that there are numerous problems with the sub-grouping approach and that it may not be an important reason for the disappointing results of clinical trials. We propose instead that current treatment may be ineffective because it has been misdirected. Recent evidence that demonstrates changes within the brain in chronic low back pain sufferers raises the possibility that persistent back pain may be a problem of cortical reorganisation and degeneration. This perspective offers interesting insights into the chronic low back pain experience and suggests alternative models of intervention. Summary: The disappointing results of clinical research are commonly explained by the failure of researchers to adequately attend to sub-grouping of the chronic non-specific low back pain population. Alternatively, current approaches may be ineffective and clinicians and researchers may need to radically rethink the nature of the problem and how it should best be managed

    Discourse or dialogue? Habermas, the Bakhtin Circle, and the question of concrete utterances

    Get PDF
    This is the author's accepted manuscript. The final publication is available at Springer via the link below.This article argues that the Bakhtin Circle presents a more realistic theory of concrete dialogue than the theory of discourse elaborated by Habermas. The Bakhtin Circle places speech within the “concrete whole utterance” and by this phrase they mean that the study of everyday language should be analyzed through the mediations of historical social systems such as capitalism. These mediations are also characterized by a determinate set of contradictions—the capital-labor contradiction in capitalism, for example—that are reproduced in unique ways in more concrete forms of life (the state, education, religion, culture, and so on). Utterances always dialectically refract these processes and as such are internal concrete moments, or concrete social forms, of them. Moreover, new and unrepeatable dialogic events arise in these concrete social forms in order to overcome and understand the constant dialectical flux of social life. But this theory of dialogue is different from that expounded by Habermas, who tends to explore speech acts by reproducing a dualism between repeatable and universal “abstract” discursive processes (commonly known as the ideal speech situation) and empirical uses of discourse. These critical points against Habermas are developed by focusing on six main areas: sentences and utterances; the lifeworld and background language; active versus passive understandings of language; validity claims; obligation and relevance in language; and dialectical universalism

    nIFTy galaxy cluster simulations – V. Investigation of the cluster infall region

    Get PDF
    We examine the properties of the galaxies and dark matter haloes residing in the cluster infall region surrounding the simulated Λ\Lambda cold dark matter galaxy cluster studied by Elahi et al. at zz = 0. The 1.1 × 1015^{15} h1h^{−1} M_\odot galaxy cluster has been simulated with eight different hydrodynamical codes containing a variety of hydrodynamic solvers and sub-grid schemes. All models completed a dark-matter-only, non-radiative and full-physics run from the same initial conditions. The simulations contain dark matter and gas with mass resolution mDMm_\text{DM} = 9.01 × 108^8 h1h^{−1} M_\odot and mgasm_\text{gas} = 1.9 × 108^8 h1h^{−1} M_\odot, respectively. We find that the synthetic cluster is surrounded by clear filamentary structures that contain ~60 per cent of haloes in the infall region with mass ~1012.5^{12.5}–1014^{14} h1h^{−1} M_\odot, including 2–3 group-sized haloes (>1013^{13} h1h^{−1} M_\odot). However, we find that only ~10 per cent of objects in the infall region are sub-haloes residing in haloes, which may suggest that there is not much ongoing pre-processing occurring in the infall region at zz = 0. By examining the baryonic content contained within the haloes, we also show that the code-to-code scatter in stellar fraction across all halo masses is typically ~2 orders of magnitude between the two most extreme cases, and this is predominantly due to the differences in sub-grid schemes and calibration procedures that each model uses. Models that do not include active galactic nucleus feedback typically produce too high stellar fractions compared to observations by at least ~1 order of magnitude.The authors would like the acknowledge the Centre for High Performance Computing in Rosebank, Cape Town, for financial support and for hosting the ‘Comparison Cape Town’ workshop in 2016, July. The authors would further like to acknowledge the support of the International Centre for Radio Astronomy Research (ICRAR) node at the University of Western Australia (UWA) in hosting the precursor workshop ‘Perth Simulated Cluster Comparison’ in 2015, March; the financial support of the UWA Research Collaboration Award 2014 and 2015 schemes; the financial support of the ARC Centre of Excellence for All Sky Astrophysics (CAASTRO) CE110001020 and ARC Discovery Projects DP130100117 and DP140100198. We would also like to thank the Instituto de Fisica Teorica (IFT-UAM/CSIC in Madrid) for its support, via the Centro de Excelencia Severo Ochoa Program under Grant No. SEV- 2012-0249, during the three-week workshop ‘nIFTy Cosmology’ in 2014, where the foundation for the whole comparison project was established. JA acknowledges support from a post-graduate award from STFC. PJE is supported by the SSimPL programme and the Sydney Institute for Astronomy (SIfA) and Australian Research Council (ARC) grants DP130100117 and DP140100198. AK is supported by the Ministerio de Econom´ıa y Competitividad (MINECO) in Spain through grant AYA2012-31101 as well as the ConsoliderIngenio 2010 Programme of the Spanish Ministerio de Ciencia e Innovacion (MICINN) under grant MultiDark CSD2009-00064. ´ He also acknowledges support from the ARC grant DP140100198. He further thanks Noonday Underground for surface noise. STK acknowledges support from STFC through grant ST/L000768/1. CP acknowledges the support of the ARC through Future Fellowship FT130100041 and Discovery Project DP140100198. WC and CP acknowledge the support of ARC DP130100117. GY and FS acknowledge support from MINECO (Spain) through the grant AYA 2012-31101. GY thanks also the Red Espanola de Supercomputa- ˜ cion for granting the computing time in the Marenostrum Supercomputer at BSC, where all the MUSIC simulations have been performed. AMB is supported by the DFG Research Unit 1254 ‘Magnetisation of interstellar and intergalactic media’ and by the DFG Cluster of Excellence ‘Universe’. GM acknowledge support from the PRIN-MIUR 2012 Grant ‘The Evolution of Cosmic Baryons’ funded by the Italian Minister of University and Research, by the PRIN-INAF 2012 Grant ‘Multi-scale Simulations of Cosmic Structures’, by the INFN INDARK Grant and by the ‘Consorzio per la Fisica di Trieste’. IGM acknowledges support from an STFC Advanced Fellowship. EP acknowledges support by the ERC grant ‘The Emergence of Structure During the Epoch of Reionization’

    TRY plant trait database - enhanced coverage and open access

    Get PDF
    Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives
    corecore