3,265 research outputs found
Statistical analysis of dwarf galaxies and their globular clusters in the Local Volume
Morphological classification of dwarf galaxies into early and late type,
though can account for some of their origin and characteristics but does not
help to study their formation mechanism. So an objective classification using
Principal Component analysis together with K means Cluster Analysis of these
dwarf galaxies and their globular clusters is carried out to overcome this
problem. It is found that the classification of dwarf galaxies in the Local
Volume is irrespective of their morphological indices. The more massive (MV 0 <
-13.7) galaxies evolve through self-enrichment and harbor dynamically less
evolved younger globular clusters (GCs) whereas fainter galaxies (MV 0 > -13.7)
are influenced by their environment in the star formation process.Comment: 22 pages, 10 figures, 5 tables, published in Ap
Hardness and elasticity in cubic ruthenium dioxide
The Knoop hardness of the highly incompressible cubic phase of ruthenium dioxide was found to be 19–20 GPa from indentation tests. This value scales well with the shear modulus approximated by the elastic constant C44 of 144 GPa obtained from Brillouin scattering measurements. This work provides evidence that the shear modulus is a better indicator of hardness than the bulk modulus for ionic and covalent materials
Relevance of intermittent rivers and streams in agricultural landscape and their impact on provided ecosystem services—a Mediterranean case study
Ecosystem services (ES), as an interconnection of the landscape mosaic pieces, along with temporal rivers (IRES) are an object of research for environmental planners and ecological economists, among other specialists. This study presents (i) a review on the importance of IRES and the services they can provide to agricultural landscapes; (ii) a classification tool to assess the impact of IRES to provide ES by agricultural landscapes; (iii) the application of the proposed classification to the Caia River in order to identify the importance of this intermittent river for its surrounding agricultural landscape. The classification of the ES follows the Common International Classification of Ecosystem (CICES) classification that was adapted for the purposes of this study. Firstly, the list of ES provided by agricultural landscape was elaborated. In the next step, we assessed the potential of IRES to provide ES. Next, IRES impacts to ES within the agricultural landscape were evaluated according to observations from the conducted field monitoring in the study area. This study focuses on the relevance of the intermittent Caia River-a transboundary river in Spain and Portugal-and its ephemeral tributaries in the agricultural landscape. Our study estimates that each hydrological phase of IRES increases the ES provided by the agricultural landscape. However, the dry phase can potentially have negative impacts on several services. The intensification of the agricultural sector is the main provision of the water resource within the Caia River basin, but we were able to identify several other ES that were positively impacted. The present study is in line with the conclusions of other authors who state that IRES constitute a valuable resource which should not be underestimated by society.Agência financiadora
COST Action
CA15113
Slovak Research and Development Agency
APVV-16-0278
UID/SOC/04020/2013info:eu-repo/semantics/publishedVersio
LIBERALIZAÇÃO FINANCEIRA E DESEMPENHO MACROECONÔMICO BRASILEIRO: EVIDÊNCIAS EMPÍRICAS A PARTIR DO MODELO VEC [FINANCIAL LIBERALIZATION AND BRAZILIAN MACROECONOMIC PERFORMANCE: SOME EMPIRICAL EVIDENCE BASED ON VEC MODEL]
RESUMO: Este artigo avalia a relação entre liberalização financeira externa – tanto abertura quanto integração financeira – e desempenho macroeconômico da economia brasileira a partir da estimação de um modelo baseado em vetores autorregressivos com correção de erros (VEC). Como contribuição potencialmente original, foi encontrada a precedência, no sentido de Granger, dos movimentos do ciclo financeiro global diante do grau de integração financeira da economia brasileira, e deste diante do risco-país. Quanto aos demais resultados, um aumento do grau de abertura da conta capital e financeira não gerou efeitos macroeconômicos significativos. Já uma elevação do grau de integração financeira teve desdobramentos problemáticos em variáveis como volatilidade cambial e nível de atividade.PALAVRAS-CHAVE: liberalização financeira; desempenho macroeconômico; Brasil=========================ABSTRACT: This paper discusses the relationship between external financial liberalization – both in terms of capital account liberalization and financial integration – and the macroeconomic performance of Brazil’s economy by estimating vector error correction model (VEC). As a potentially original contribution, it has been found a causal relation, in Grange sense, between the global financial movements and the degree of financial integration and between the latter and the country risk. Also, evidence has been found that an increased degree of capital account liberalization did not produce relevant macroeconomic effects. Additionally, results show that a high degree of financial integration had problematic repercussions in variables such as exchange rate volatility and activity level.KEYWORDS: financial liberalization; macroeconomic performance; Brazi
ACCESS IV: The quenching of star formation in a cluster population of dusty S0s
We present an analysis of the mid-infrared (MIR) colours of 165 70um-detected
galaxies in the Shapley supercluster core (SSC) at z=0.048 using panoramic
Spitzer/MIPS 24 and 70um imaging. While the bulk of galaxies show f70/f24
colours typical of local star-forming galaxies, we identify a significant
sub-population of 23 70micron-excess galaxies, whose MIR colours (f70/f24>25)
are much redder and cannot be reproduced by any of the standard model infrared
SEDs. These galaxies are found to be strongly concentrated towards the cores of
the five clusters that make up the SSC, and also appear rare among local field
galaxies, confirming them as a cluster-specific phenomenon. Their optical
spectra and lack of significant UV emission imply little or no ongoing star
formation, while fits to their panchromatic SEDs require the far-IR emission to
come mostly from a diffuse dust component heated by the general interstellar
radiation field rather than ongoing star formation. Most of these
70micron-excess galaxies are identified as ~L* S0s with smooth profiles. We
find that almost every cluster galaxy in the process of star-formation
quenching is already either an S0 or Sa, while we find no passive galaxies of
class Sb or later. Hence the formation of passive early-type galaxies in
cluster cores must involve the prior morphological transformation of late-type
spirals into Sa/S0s, perhaps via pre-processing or the impact of cluster tidal
fields, before a subsequent quenching of star formation once the lenticular
encounters the dense environment of the cluster core. In the cases of many
cluster S0s, this phase of star-formation quenching is characterised by an
excess of 70um emission, indicating that the cold dust content is declining at
a slower rate than star formation.Comment: 17 pages, 12 figures. Accepted for publication in MNRA
Infrared properties of the SDSS-maxBCG galaxy clusters
The physics of galaxy clusters has proven to be influenced by several
processes connected with their galactic component which pollutes the ICM with
metals, stars and dust. However, it is not clear whether the presence of
diffuse dust can play a role in clusters physics since a characterisation of
the IR properties of galaxy clusters is yet to be completely achieved. We focus
on the recent work of Giard et al. (2008) who performed a stacking analysis of
the IRAS data in the direction of several thousands of galaxy clusters,
providing a statistical characterisation of their IR luminosity and redshift
evolution. We model the IR properties of the galactic population of the
SDSS-maxBCG clusters (0.1<z<0.3) in order to check if it accounts for the
entire observed signal and to constrain the possible presence of other
components, like dust in the ICM. Starting from the optical properties of the
galaxy members, we estimate their emission in the 60 and 100 micron IRAS bands
making use of modeled SEDs of different spectral types (E/S0, Sa, Sb, Sc and
starburst). We also consider the evolution of the galactic
population/luminosity with redshift. Our results indicate that the galactic
emission, which is dominated by the contribution of star-forming galaxies, is
consistent with the observed signal. In fact, our model slightly overestimates
the observed fluxes, with the excess being concentrated in low-redshift
clusters (z <~ 0.17). This indicates that, if present, the IR emission from
intracluster dust must be very small. We obtain an upper limit on the
dust-to-gas mass ratio in the ICM of Z_d <~ 5 10^-5. The excess in luminosity
obtained at low redshift constitutes an indication that the cluster environment
is driving a process of star-formation quenching in its galaxy members.Comment: 12 pages, 6 figures, 2 tables. Accepted for publication in A&
General practitioners' use and experiences of palliative care services: a survey in south east England
<p>Abstract</p> <p>Background</p> <p>The role of the General Practitioner (GP) is central to community palliative care. Good liaison between the different professionals involved in a patient's care is extremely important in palliative care patients. In cases where GPs have previously been dissatisfied with palliative services, this may be seen as a barrier to referral when caring for other patients. The aim of this survey is to investigate the use and previous experiences of GPs of two palliative care services, with particular emphasis on barriers to referral and to explore issues surrounding the GP's role in caring for palliative patients.</p> <p>Methods</p> <p>Design: Descriptive postal survey of use and experience of palliative care services with particular emphasis on barriers to referral. Setting: One Primary Care Trust (PCT), south London, England, population 298,500. Subjects: 180 GPs in the PCT, which is served by two hospice services (A&B).</p> <p>Results</p> <p>An overall questionnaire response rate of 77% (138) was obtained, with 69% (124) used in analysis. Over 90% of GPs were satisfied with the palliative care services over the preceding two years. Two areas of possible improvement emerged; communication and prescribing practices. GPs identified some patients that they had not referred, most commonly when patients or carers were reluctant to accept help, or when other support was deemed sufficient. Over half of the GPs felt there were areas where improvement could be made; with clarification of the rules and responsibilities of the multi disciplinary team being the most common. The majority of GPs were working, and want to work with, the specialist services as part of an extended team. However, a greater number of GPs want to hand over care to the specialist services than are currently doing so.</p> <p>Conclusion</p> <p>A large number of GPs were happy with the service provision of the palliative care services in this area. They suggested that 3 out of 4 terminally ill patients needed specialist input. Views of services were largely positive, and reasons for non referral were unrelated to previous experience of the specialist services.</p
Mortality after admission for acute myocardial infarction in Aboriginal and non-Aboriginal people in New South Wales, Australia: a multilevel data linkage study
Background - Heart disease is a leading cause of the gap in burden of disease between Aboriginal and non-Aboriginal Australians. Our study investigated short- and long-term mortality after admission for Aboriginal and non-Aboriginal people admitted with acute myocardial infarction (AMI) to public hospitals in New South Wales, Australia, and examined the impact of the hospital of admission on outcomes.
Methods - Admission records were linked to mortality records for 60047 patients aged 25–84 years admitted with a diagnosis of AMI between July 2001 and December 2008. Multilevel logistic regression was used to estimate adjusted odds ratios (AOR) for 30- and 365-day all-cause mortality.
Results - Aboriginal patients admitted with an AMI were younger than non-Aboriginal patients, and more likely to be admitted to lower volume, remote hospitals without on-site angiography. Adjusting for age, sex, year and hospital, Aboriginal patients had a similar 30-day mortality risk to non-Aboriginal patients (AOR: 1.07; 95% CI 0.83-1.37) but a higher risk of dying within 365 days (AOR: 1.34; 95% CI 1.10-1.63). The latter difference did not persist after adjustment for comorbid conditions (AOR: 1.12; 95% CI 0.91-1.38). Patients admitted to more remote hospitals, those with lower patient volume and those without on-site angiography had increased risk of short and long-term mortality regardless of Aboriginal status.
Conclusions - Improving access to larger hospitals and those with specialist cardiac facilities could improve outcomes following AMI for all patients. However, major efforts to boost primary and secondary prevention of AMI are required to reduce the mortality gap between Aboriginal and non-Aboriginal people
Fatigue strength of common tibial intramedullary nail distal locking screws
Premature failure of either the nail and/or locking screws with unstable fracture patterns may lead to angulation, shortening, malunion, and IM nail migration. Up to thirty percent of all unreamed nail locking screws can break after initial weight bearing is allowed at 8–10 weeks if union has not occurred. The primary problem this presents is hardware removal during revision surgery. The purposes of our study was to evaluate the relative fatigue resistance of distal locking screws and bolts from representative manufacturers of tibial IM nail systems, and develop a relative risk assessment of screws and materials used. Evaluations included quantitative and qualitative measures of the relative performance of these screws
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