204 research outputs found

    Further Evidence for a Merger Origin for the Thick Disk: Galactic Stars Along Lines-of-sight to Dwarf Spheroidal Galaxies

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    The history of the Milky Way Galaxy is written in the properties of its stellar populations. Here we analyse stars observed as part of surveys of local dwarf spheroidal galaxies, but which from their kinematics are highly probable to be non-members. The selection function -- designed to target metal-poor giants in the dwarf galaxies, at distances of ~100kpc -- includes F-M dwarfs in the Milky Way, at distances of up to several kpc. Thestars whose motions are analysed here lie in the cardinal directions of Galactic longitude l ~ 270 and l ~ 90, where the radial velocity is sensitive to the orbital rotational velocity. We demonstrate that the faint F/G stars contain a significant population with V_phi ~ 100km/s, similar to that found by a targeted, but limited in areal coverage, survey of thick-disk/halo stars by Gilmore, Wyse & Norris (2002). This value of mean orbital rotation does not match either the canonical thick disk or the stellar halo. We argue that this population, detected at both l ~ 270 and l ~ 90, has the expected properties of `satellite debris' in the thick-disk/halo interface, which we interpret as remnants of the merger that heated a pre-existing thin disk to form the thick disk.Comment: Accepted, Astrophysical Journal Letter

    Clinical staff perceptions on the quality of end-of-life care in an Australian acute private hospital: A cross-sectional survey

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    Objective: To explore the perceptions of clinical staff on the quality of end-of-life care in an acute private hospital. Methods: A descriptive cross-sectional study with a convenience sample of clinical staff in an acute private hospital were surveyed using a validated end-of-life survey. Data from the surveys were analysed using descriptive statistics for quantitative responses and inductive content analysis for the open-ended responses. Results: Overall, 133 staff completed the survey. Of these, 107 had cared for a dying patient in the hospital. In total, 87.6% of participants felt confident in their ability to recognise a dying patient and 66.7% felt confident in their ability to talk to the patient and family. Almost one-third had not received specific training in the area. Conclusions: Hospitals need to take the lead in ensuring end-of-life care processes are embedded across clinical areas. This includes providing staff with end-of-life care education and support in the delivery of end-of-life care. These strategies will facilitate safe and quality end-of-life care, including better collaboration between patients, families and staff

    Who knows best? Older people’s contribution to understanding and preventing avoidable hospital admissions

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    A report outlining the findings from a research project into older people's experiences of emergency admission to hospital and the possibilities for prevention. The overall study was funded by the NIHR Research for Patient Benefit programme (PB–PG–0712–28045), albeit the conclusions drawn are those of the research team and do not necessarily reflect those of the NIHR, the Department of Health or the NHS/social care. This research was carried out at the University of Birmingham

    Health effects of adopting low greenhouse gas emission diets in the UK.

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    OBJECTIVE: Dietary changes which improve health are also likely to be beneficial for the environment by reducing emissions of greenhouse gases (GHG). However, previous analyses have not accounted for the potential acceptability of low GHG diets to the general public. This study attempted to quantify the health effects associated with adopting low GHG emission diets in the UK. DESIGN: Epidemiological modelling study. SETTING: UK. PARTICIPANTS: UK population. INTERVENTION: Adoption of diets optimised to achieve the WHO nutritional recommendations and reduce GHG emissions while remaining as close as possible to existing dietary patterns. MAIN OUTCOME: Changes in years of life lost due to coronary heart disease, stroke, several cancers and type II diabetes, quantified using life tables. RESULTS: If the average UK dietary intake were optimised to comply with the WHO recommendations, we estimate an incidental reduction of 17% in GHG emissions. Such a dietary pattern would be broadly similar to the current UK average. Our model suggests that it would save almost 7 million years of life lost prematurely in the UK over the next 30 years and increase average life expectancy by over 8 months. Diets that result in additional GHG emission reductions could achieve further net health benefits. For emission reductions greater than 40%, improvements in some health outcomes may decrease and acceptability will diminish. CONCLUSIONS: There are large potential benefits to health from adopting diets with lower associated GHG emissions in the UK. Most of these benefits can be achieved without drastic changes to existing dietary patterns. However, to reduce emissions by more than 40%, major dietary changes that limit both acceptability and the benefits to health are required

    Profiles of family-focused adverse experiences through childhood and early adolescence: the ROOTS project a community investigation of adolescent mental health.

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    BACKGROUND: Adverse family experiences in early life are associated with subsequent psychopathology. This study adds to the growing body of work exploring the nature and associations between adverse experiences over the childhood years. METHODS: Primary carers of 1143 randomly recruited 14-year olds in Cambridgeshire and Suffolk, UK were interviewed using the Cambridge Early Experiences Interview (CAMEEI) to assess family-focused adversities. Adversities were recorded retrospectively in three time periods (early and later childhood and early adolescence). Latent Class Analysis (LCA) grouped individuals into adversity classes for each time period and longitudinally. Adolescents were interviewed to generate lifetime DSM-IV diagnoses using the K-SADS-PL. The associations between adversity class and diagnoses were explored. RESULTS: LCA generated a 4-class model for each time period and longitudinally. In early childhood 69% were allocated to a low adversity class; a moderate adversity class (19%) showed elevated rates of family loss, mild or moderate family discord, financial difficulties, maternal psychiatric illness and higher risk for paternal atypical parenting; a severe class (6%) experienced higher rates on all indicators and almost exclusively accounted for incidents of child abuse; a fourth class, characterised by atypical parenting from both parents, accounted for the remaining 7%. Class membership was fairly stable (~ 55%) over time with escape from any adversity by 14 years being uncommon. Compared to those in the low class, the odds ratio for reported psychopathology in adolescents in the severe class ranged from 8 for disruptive behaviour disorders through to 4.8 for depressions and 2.0 for anxiety disorders. Only in the low adversity class did significantly more females than males report psychopathology. CONCLUSIONS: Family adversities in the early years occur as multiple rather than single experiences. Although some children escape adversity, for many this negative family environment persists over the first 15 years of life. Different profiles of family risk may be associated with specific mental disorders in young people. Sex differences in psychopathologies may be most pronounced in those exposed to low levels of family adversities.This is the published version of the article. It was published in BMC Psychiatry by BioMed Central. The online version can be found here: http://www.biomedcentral.com/1471-244X/11/109

    The Abundance Spread in the Bootes I Dwarf Spheroidal Galaxy

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    We present medium-resolution spectra of 16 radial velocity red-giant members of the low-luminosity Bootes I dwarf spheroidal (dSph) galaxy that have sufficient S/N for abundance determination, based on the strength of the Ca ii K line. Assuming [Ca/Fe]-0.3, the abundance range in the sample is Δ[Fe/H]-1.7 dex, with one star having [Fe/H]=-3.4. The dispersion is σ([Fe/H])=0.45 ± 0.08-similar to those of the Galaxy's more luminous dSph systems and ω Centauri. This suggests that the large mass (⊙≥10 7 M&o) normally assumed to foster self-enrichment and the production of chemical abundance spreads was provided by the nonbaryonic material in Boötes I

    What is a galaxy? How Cold is Cold Dark Matter? Recent progress in Near Field Cosmology

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    There has been a vast recent improvement in photometric and kinematic data for star clusters, Ultra Compact dwarfs, galactic nuclei, and local dSph galaxies, with Subaru contributing substantially to the photometric studies in particular. These data show that there is a bimodal distribution in half-light radii, with stable star clusters always being smaller than 35pc, while stable galaxies are always larger than 120pc. We extend the previously known observational relationships and interpret them in terms of a more fundamental pair of intrinsic properties of dark matter itself: dark matter forms cored mass distributions, with a core scale length of greater than about 100pc, and always has a maximum central mass density with a narrow range. The dark matter in dSph galaxies appears to be clustered such that there is a mean volume mass density within the stellar distribution which has the very low value of about 0.1M⊙M_{\odot} pc−3^{-3}. None of the dSphs displays kinematics which require the presence of an inner cusp, while in two dSphs there is evidence that the density profile is shallow (cored) in the inner regions. The maximum central dark matter density derived is model dependent, but is likely to have a mean value (averaged over a volume of radius 10pc) of about 0.1M⊙M_{\odot} pc−3^{-3}, which is 5GeV/c2^2cm−3^{-3}). Galaxies are embedded in dark matter halos with these properties; smaller systems containing dark matter are not observed.Comment: proceedings of The 1st Subaru International Conference, "Panoramic Views of Galaxy Formation and Evolution" (Hayama, Japan, 11-16 Dec 2007) ASP Conf se

    Complexity on Small Scales II: Metallicities and Ages in the Leo II Dwarf Spheroidal Galaxy

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    We present metallicities and ages for 52 red giants in the remote Galactic dwarf spheroidal (dSph) galaxy Leo II. These stars cover the entire surface area of Leo II and are radial velocity members. We obtained medium-resolution multi-fiber spectroscopy with ESO/VLT's FLAMES spectrograph. The metallicities were determined based on the near-infrared Ca II triplet. The resulting metallicity distribution (MD) is asymmetric and peaks at [Fe/H]=-1.74 dex on the Carretta & Gratton scale. The full range in metallicities extends from -2.4 to -1.1 dex. As in other dSphs, no extremely metal-poor red giants were found. We compare Leo II's observed MD with model predictions for several other Galactic dSphs from the literature. Leo II clearly exhibits a lack of more metal poor stars, in analogy to the classical G-dwarf problem, which may indicate a comparable `K-giant problem'. Moreover, its evolution appears to have been affected by galactic winds. We use our inferred metallicities as an input parameter for isochrone fits to SDSS photometry and derive approximate ages. The resulting age-metallicity distribution covers the full age range from 2-15 Gyr on our adopted isochrone scale. During the first 7 Gyr relative to the oldest stars [Fe/H] appears to have remained almost constant. The almost constant metallicity at higher ages and a slight drop by about 0.3 dex thereafter may be indicative of rejuvenation by low metallicity gas. Overall, the age-metallicity relation appears to support the formation of Leo II from pre-enriched gas. Evidence for enrichment is seen during the recent 2-4 Gyr. Our findings support earlier photometric findings of Leo II as a galaxy with a prominent old and a dominant intermediate-age population. We do not find a significant radial metallicity gradient nor age gradient in our data.(Abridged)Comment: 23 pages, 12 Figures, accepted for publication in the A

    Impact on mortality of pathways to net zero greenhouse gas emissions in England and Wales: a multisectoral modelling study.

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    BACKGROUND: The UK is legally committed to reduce its greenhouse gas emissions to net zero by 2050. We aimed to understand the potential impact on population health of two pathways for achieving this target through the integrated effects of six actions in four sectors. METHODS: In this multisectoral modelling study we assessed the impact on population health in England and Wales of six policy actions relating to electricity generation, transport, home energy, active travel, and diets relative to a baseline scenario in which climate actions, exposures, and behaviours were held constant at 2020 levels under two scenarios: the UK Climate Change Committee's Balanced Pathway of technological and behavioural measures; and its Widespread Engagement Pathway, which assumes more substantial changes to consumer behaviours. We quantified the impacts of each policy action on mortality using a life table comprising all exposures, behaviours, and health outcomes in a single model. FINDINGS: Both scenarios are predicted to result in substantial reductions in mortality by 2050. The Widespread Engagement Pathway achieves a slightly greater reduction in outdoor fine particulate matter air pollution of 3·2 μg/m3 (33%) and, under assumptions of appropriate ventilation, a greater improvement in indoor air pollution (a decrease in indoor-generated fine particulate matter from 9·4 μg/m3 to 4·6 μg/m3) and winter temperatures (increasing from 17·8°C to 18·1°C), as well as appreciably greater changes in levels of active travel (27% increase in metabolic equivalent hours per week of walking and cycling) by 2050. Additionally, the greater reduction in red meat consumption (50% compared with 35% under the Balanced Pathway) by 2050 results in greater consumption of fruits (17-18 g/day), vegetables (22-23 g/day), and legumes (5-7 g/day). Combined actions under the Balanced Pathway result in more than 2 million cumulative life-years gained over 2021-50; the estimated gain under the Widespread Engagement Pathway is greater, corresponding to nearly 2·5 million life-years gained by 2050 and 13·7 million life-years gained by 2100. INTERPRETATION: Reaching net zero greenhouse gas emissions is likely to lead to substantial benefits for public health in England and Wales, with the cumulative net benefits being correspondingly greater with a pathway that entails faster and more ambitious changes, especially in physical activity and diets. FUNDING: National Institute for Health Research and the Wellcome Trust
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