298 research outputs found
Lambda-Cold Dark Matter, Stellar Feedback, and the Galactic Halo Abundance Pattern
(Abridged) The hierarchical formation scenario for the stellar halo requires
the accretion and disruption of dwarf galaxies, yet low-metallicity halo stars
are enriched in alpha-elements compared to similar, low-metallicity stars in
dwarf spheroidal (dSph) galaxies. We address this primary challenge for the
hierarchical formation scenario for the stellar halo by combining chemical
evolution modelling with cosmologically-motivated mass accretion histories for
the Milky Way dark halo and its satellites. We demonstrate that stellar halo
and dwarf galaxy abundance patterns can be explained naturally within the LCDM
framework. Our solution relies fundamentally on the LCDM model prediction that
the majority of the stars in the stellar halo were formed within a few
relatively massive, ~5 x 10^10 Msun, dwarf irregular (dIrr)-size dark matter
halos, which were accreted and destroyed ~10 Gyr in the past. These systems
necessarily have short-lived, rapid star formation histories, are enriched
primarily by Type II supernovae, and host stars with enhanced [a/Fe]
abundances. In contrast, dwarf spheroidal galaxies exist within low-mass dark
matter hosts of ~10^9 Msun, where supernovae winds are important in setting the
intermediate [a/Fe] ratios observed. Our model includes enrichment from Type Ia
and Type II supernovae as well as stellar winds, and includes a
physically-motivated supernovae feedback prescription calibrated to reproduce
the local dwarf galaxy stellar mass - metallicity relation. We use
representative examples of the type of dark matter halos we expect to host a
destroyed ``stellar halo progenitor'' dwarf, a surviving dIrr, and a surviving
dSph galaxy, and show that their derived abundance patterns, stellar masses,
and gas masses are consistent with those observed for each type of system.Comment: 10 pages, 3 figures, version accepted by Ap
Gestational Diabetes Augments Group B Streptococcus Infection by Disrupting Maternal Immunity and the Vaginal Microbiota
Group B Streptococcus (GBS) is a pervasive perinatal pathogen, yet factors driving GBS dissemination in utero are poorly defined. Gestational diabetes mellitus (GDM), a complication marked by dysregulated immunity and maternal microbial dysbiosis, increases risk for GBS perinatal disease. Using a murine GDM model of GBS colonization and perinatal transmission, we find that GDM mice display greater GBS in utero dissemination and subsequently worse neonatal outcomes. Dual-RNA sequencing reveals differential GBS adaptation to the GDM reproductive tract, including a putative glycosyltransferase (yfhO), and altered host responses. GDM immune disruptions include reduced uterine natural killer cell activation, impaired recruitment to placentae, and altered maternofetal cytokines. Lastly, we observe distinct vaginal microbial taxa associated with GDM status and GBS invasive disease status. Here, we show a model of GBS dissemination in GDM hosts that recapitulates several clinical aspects and identifies multiple host and bacterial drivers of GBS perinatal disease
'I just want to watch the match': a practitioner's reflective account of men's health themed match day events at an English Premier League football club
This study reflects on the effectiveness and delivery of a series of health themed match day events at an English Premier League Football Club which aimed to create awareness and motivate men to adopt recommended health behaviours. A range of marketing techniques and activities were adopted within a targeted space and time to increase men's exposure to health information. The first author adopted a practitioner-cum-researcher role and was immersed in the planning and delivery of the events utilising the principles of ethnography. Data were predominately collated through observations and personal reflections logged via autobiographical field notes. Data were analysed through abductive reasoning. In general, men were reluctant to engage in health-related behaviours on match days. However, subtle, non-invasive approaches were deemed successful. Positive outcomes and case studies from the latter techniques are presented and suggestions for effective strategies that will better engage men in health information and behaviours are made. © 2014 © 2014 Taylor & Francis
How people with dementia and their families decide about moving to a care home and support their needs: development of a decision aid, a qualitative study
yesBackground: People with dementia and their relatives find decisions about the person with dementia living in a care home difficult.
Methods: We interviewed 20 people with dementia or family carers around the time of this decision in order to design a decision-aid.
Results: Decision-makers balanced the competing priorities of remaining somewhere familiar, familyâs wish they
remain at home, reduction of risk and effects on carerâs and person with dementiaâs physical health. The person with dementia frequently resented their lack of autonomy as decisions about care home moves were made after insight and judgment were impaired. Family consultation usually helped carers but sometimes exacerbated tensions. Direct professional support was appreciated where it was available. There is a need for healthcare
professionals to facilitate these conversations around decision-making and to include more than signposting to
other organisations.
Conclusions: There is a need for a healthcare professional facilitated decision-aid. This should detail what might change for the person with dementia and their carer, possible resources and alternatives and assist in facilitating discussion with the wider family; further research will develop and test a tool to facilitate decision making about
place of care needs
Why alternative teenagers self-harm: exploring the link between non-suicidal self-injury, attempted suicide and adolescent identity
Background:
The term âself-harmâ encompasses both attempted suicide and non-suicidal self-injury (NSSI). Specific adolescent subpopulations such as ethnic or sexual minorities, and more controversially, those who identify as âAlternativeâ (Goth, Emo) have been proposed as being more likely to self-harm, while other groups such as âJocksâ are linked with protective coping behaviours (for example exercise). NSSI has autonomic (it reduces negative emotions) and social (it communicates distress or facilitates group âbondingâ) functions. This study explores the links between such aspects of self-harm, primarily NSSI, and youth subculture.<p></p>
Methods:
An anonymous survey was carried out of 452 15 year old German school students. Measures included: identification with different youth cultures, i.e. Alternative (Goth, Emo, Punk), Nerd (academic) or Jock (athletic); social background, e.g. socioeconomic status; and experience of victimisation. Self-harm (suicide and NSSI) was assessed using Self-harm Behavior Questionnaire and the Functional Assessment of Self-Mutilation (FASM).<p></p>
Results:
An âAlternativeâ identity was directly (râââ0.3) and a âJockâ identity inversely (râââ-0.1) correlated with self-harm. âAlternativeâ teenagers self-injured more frequently (NSSI 45.5% vs. 18.8%), repeatedly self-injured, and were 4â8 times more likely to attempt suicide (even after adjusting for social background) than their non-Alternative peers. They were also more likely to self-injure for autonomic, communicative and social reasons than other adolescents.<p></p>
Conclusions:
About half of âAlternativeâ adolescentsâ self-injure, primarily to regulate emotions and communicate distress. However, a minority self-injure to reinforce their group identity, i.e. âTo feel more a part of a groupâ
D'Annunzio sulla scena lirica: libretto o "Poema"?
Australia Direct Action climate change policy relies on purchasing greenhouse gas abatement from projects undertaking approved abatement activities. Management of soil organic carbon (SOC) in agricultural soils is an approved activity, based on the expectation that land use change can deliver significant changes in SOC. However, there are concerns that climate, topography and soil texture will limit changes in SOC stocks. This work analyses data from 1482 sites surveyed across the major agricultural regions of Eastern Australia to determine the relative importance of land use vs. other drivers of SOC. Variation in land use explained only 1.4% of the total variation in SOC, with aridity and soil texture the main regulators of SOC stock under different land uses. Results suggest the greatest potential for increasing SOC stocks in Eastern Australian agricultural regions lies in converting from cropping to pasture on heavy textured soils in the humid regions
Probing the Halo From the Solar Vicinity to the Outer Galaxy: Connecting Stars in Local Velocity Structures to Large-Scale Clouds
(Abridged) This paper presents the first connections made between two local
features in velocity-space found in a survey of M giant stars and stellar
spatial inhomogeneities on global scales. Comparison to cosmological,
chemodynamical stellar halo models confirm that the M giant population is
particularly sensitive to rare, recent and massive accretion events. These
events can give rise to local observed velocity sequences - a signature of a
small fraction of debris from a common progenitor, passing at high velocity
through the survey volume, near the pericenters of their eccentric orbits. The
majority of the debris is found in much larger structures, whose morphologies
are more cloud-like than stream-like and which lie at the orbital apocenters.
Adopting this interpretation, the full-space motions represented by the
observed velocity features are derived under the assumption that the members
within each sequence share a common velocity. Orbit integrations are then used
to trace the past and future trajectories of these stars across the sky
revealing plausible associations with large, previously-discovered, cloud-like
structures. The connections made between nearby velocity structures and these
distant clouds represent preliminary steps towards developing coherent maps of
such giant debris systems. These maps promise to provide new insights into the
origin of debris clouds, new probes of Galactic history and structure, and new
constraints on the high-velocity tails of the local dark matter distribution
that are essential for interpreting direct detection experiments.Comment: submitted to the Astrophysical Journal, 40 pages, 13 figure
The ENIGMA Stroke Recovery Working Group: Big data neuroimaging to study brainâbehavior relationships after stroke
The goal of the Enhancing Neuroimaging Genetics through MetaâAnalysis (ENIGMA) Stroke Recovery working group is to understand brain and behavior relationships using wellâpowered metaâ and megaâanalytic approaches. ENIGMA Stroke Recovery has data from over 2,100 stroke patients collected across 39 research studies and 10 countries around the world, comprising the largest multisite retrospective stroke data collaboration to date. This article outlines the efforts taken by the ENIGMA Stroke Recovery working group to develop neuroinformatics protocols and methods to manage multisite stroke brain magnetic resonance imaging, behavioral and demographics data. Specifically, the processes for scalable data intake and preprocessing, multisite data harmonization, and largeâscale stroke lesion analysis are described, and challenges unique to this type of big data collaboration in stroke research are discussed. Finally, future directions and limitations, as well as recommendations for improved data harmonization through prospective data collection and data management, are provided
IMCI and ETAT Integration at a Primary Healthcare Facility in Malawi:A Human Factors Approach
Abstract Background Integrated Management of Childhood Illness (IMCI) and Emergency Triage, Assessment and Treatment (ETAT) are guidelines developed by the World Health Organization to reach targets for reducing under-5 mortality. They were set out in the Millennium Development Goals. Each guideline was established separately so the purpose of this study was to understand how these systems have been integrated in a primary care setting and identify barriers and facilitators to this integration using a systems approach. Method Interviews were carried out with members of staff of different levels within a primary healthcare clinic in Malawi. Along with observations from the clinic this provided a well-rounded view of the running of the clinic. This data was then analysed using the SEIPS 2.0 work systems framework. The work system elements specified in this model were used to identify and categorise themes that influenced the clinicâs efficiency. Results A process map of the flow of patients through the clinic was created, showing the tasks undertaken and the interactions between staff and patients. In their interviews, staff identified several organisational elements that served as barriers to the implementation of care. They included workload, available resources, ineffective time management, delegation of roles and adaptation of care. In terms of the external environment there was a lack of clarity over the two sets of guidelines and how they were to be integrated which was a key barrier to the process. Under the heading of tools and technology a lack of guideline copies was identified as a barrier. However, the health passport system and other forms of recording were highlighted as being important facilitators. Other issues highlighted were the lack of transport provided, challenges regarding teamwork and attitudes of members of staff, patient factors such as their beliefs and regard for the care and education provided by the clinic. Conclusions This study provides the first information on the challenges and issues involved in combining IMCI and ETAT and identified a number of barriers. These barriers included a lack of resources, staff training and heavy workload. This provided areas to work on in order to improve implementation
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