7,283 research outputs found

    Physical Properties of Galactic Planck Cold Cores revealed by the Hi-GAL survey

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    Previous studies of the initial conditions of massive star formation have mainly targeted Infrared-Dark Clouds (IRDCs) toward the inner Galaxy. This is due to the fact that IRDCs were first detected in absorption against the bright mid-IR background, requiring a favourable location to be observed. By selection, IRDCs represent only a fraction of the Galactic clouds capable of forming massive stars and star clusters. Due to their low dust temperatures, IRDCs are bright in the far-IR and millimeter and thus, observations at these wavelengths have the potential to provide a complete sample of star-forming massive clouds across the Galaxy. Our aim is to identify the clouds at the initial conditions of massive star formation across the Galaxy and compare their physical properties as a function of their Galactic location. We have examined the physical properties of a homogeneous galactic cold core sample obtained with the Planck satellite across the Galactic Plane. With the use of Herschel Hi-GAL observations, we have characterized the internal structure of them. By using background-subtracted Herschel images, we have derived the H2 column density and dust temperature maps for 48 Planck clumps. Their basic physical parameters have been calculated and analyzed as a function of location within the Galaxy. These properties have also been compared with the empirical relation for massive star formation derived by Kauffmann & Pillai (2010). Most of the Planck clumps contain signs of star formation. About 25% of them are massive enough to form high mass stars. Planck clumps toward the Galactic center region show higher peak column densities and higher average dust temperatures than those of the clumps in the outer Galaxy. Although we only have seven clumps without associated YSOs, the Hi-GAL data show no apparent differences in the properties of Planck cold clumps with and without star formation.Comment: 22 pages, 11 figures, accepted for publication in A&

    Deep spectroscopic luminosity function of Abell 85: no evidence for a steep upturn of the faint-end slope

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    We present a new deep determination of the spectroscopic LF within the virial radius of the nearby and massive Abell\,85 (A85) cluster down to the dwarf regime (M* + 6) using VLT/VIMOS spectra for 2000\sim 2000 galaxies with mr21_r \leq 21 mag and μe,r24\langle \mu_{e,r} \rangle \leq 24 mag arcsec2^{-2}. The resulting LF from 438 cluster members is best modelled by a double Schechter function due to the presence of a statistically significant upturn at the faint-end. The amplitude of this upturn (αf=1.580.15+0.19\alpha_{f} = -1.58^{+0.19}_{-0.15}), however, is much smaller than that of the SDSS composite photometric cluster LF by Popesso et al. 2006, αf\alpha_{f} \sim -2. The faint-end slope of the LF in A85 is consistent, within the uncertainties, with that of the field. The red galaxy population dominates the LF at low luminosities, and is the main responsible for the upturn. The fact that the slopes of the spectroscopic LFs in the field and in a cluster as massive as A85 are similar suggests that the cluster environment does not play a major role in determining the abundance of low-mass galaxies.Comment: 6 pages, 4 figures, accepted at MNRAS lette

    Cauchy's formulas for random walks in bounded domains

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    Cauchy's formula was originally established for random straight paths crossing a body BRnB \subset \mathbb{R}^{n} and basically relates the average chord length through BB to the ratio between the volume and the surface of the body itself. The original statement was later extended in the context of transport theory so as to cover the stochastic paths of Pearson random walks with exponentially distributed flight lengths traversing a bounded domain. Some heuristic arguments suggest that Cauchy's formula may also hold true for Pearson random walks with arbitrarily distributed flight lengths. For such a broad class of stochastic processes, we rigorously derive a generalized Cauchy's formula for the average length travelled by the walkers in the body, and show that this quantity depends indeed only on the ratio between the volume and the surface, provided that some constraints are imposed on the entrance step of the walker in BB. Similar results are obtained also for the average number of collisions performed by the walker in BB, and an extension to absorbing media is discussed.Comment: 12 pages, 6 figure

    Understanding the gendered coaching workforce in Spanish sport

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    The present study focuses on the demographic and labor characteristics of coaches in Spain. Kanter’s theory on occupational sex segregation will be used as a guiding framework. The study was conducted with 1685 coaches (82.3% men and 17.7% women) from different sports and performance domains. The results show that there is an underrepresentation of women as coaches in Spain and data highlight that coaches’ gender is related to three structural factors: opportunity, power, and proportion. The present data reveal that women are younger, less likely to be in a marriage-like relationship, less likely to have children, and more likely to have competed at a high level as an athlete when compared to their male counterparts. However, fewer women than men access and participate in coach education in Catalonia and the working status of women was different to that of men. To expand, women worked less hours, were more likely to be assistant coaches, and had less years of coaching experience. Understanding of how gender influences women’s access, progression, and retention in coaching in Spain illustrates the need for gender sport policies and practices in sport organizations. This approach can benefit not only women, but the diversity and enrichment of the coaching system

    Evaluation of diabetic foot amputation rate

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    Acta Med Port. 2003 Nov-Dec;16(6):373-80. Epub 2003 Dec 1. [Evaluation of diabetic foot amputation rate]. [Article in Portuguese] Horta C, Vilaverde J, Mendes P, Gonçalves I, Serra L, Pinto PS, Almeida R, Carvalho R, Dores J, Serra MB. Serviços de Endocrinologia, Ortopedia e Cirurgia Vascular, Hospital Geral de Santo António, Porto. Abstract In 1987, it was created the first portuguese Diabetic Foot Clinic in Oporto, at the Hospital Geral de Santo António. The distinction between neuropathic and ischaemic foot was the key stone to reduce drastically the rate of major amputations in the first two years of activity. Since then and until 1995 the rate of major amputations had stabilised around 8%. The aim of the present study was to evaluate if there was any change in the last three years. A retrospective study was performed reviewing the clinical files of 843 new patients between 1998 and 2000. The 593 patients who presented with a foot ulcer with or without infection were selected: 60.4% with neuropathic foot and 39.6% with ischaemic one. Overall, 31 of the 593 patients with ulcer or infection were treated with major amputation (5.2%). There was a statistical difference between the major amputation outcome among the two types of foot (p < 0.001). Necrosis showed to carry a poor prognosis (30.7% in ischaemic foot vs 8,3% in neuropathic, p = 0.024). There was no further statistical significance for age, sex, type or duration of diabetes as risk factors for major amputation. This retrospective study has showed a slight reduction in the rate of major amputations since 1995. Poor prognosis was related to necrosis and ischaemic foot. Further improvement requires harder investment in patients' education, as well as in alerting the primary health care physicians, for the most unpredictable catastrophic complication of diabetes. PMID: 15631847 [PubMed - indexed for MEDLINE

    Experimentally Witnessing the Quantumness of Correlations

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    The quantification of quantum correlations (other than entanglement) usually entails laboured numerical optimization procedures also demanding quantum state tomographic methods. Thus it is interesting to have a laboratory friendly witness for the nature of correlations. In this Letter we report a direct experimental implementation of such a witness in a room temperature nuclear magnetic resonance system. In our experiment the nature of correlations is revealed by performing only few local magnetization measurements. We also compare the witness results with those for the symmetric quantum discord and we obtained a fairly good agreement

    New Methodology for the Classification of Gravel Beaches: Adjusted on Alicante (Spain)

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    [EN] In this article, a methodology is presented for the classification of gravel beaches, which can be applied internationally. Such beaches¿ defence against the energy of incoming water flow is due to their steep slopes and the high permeability of infiltration, but that defence is reduced with increasing sand fraction. The objective of this research was to understand the variables involved in the formation of gravel beaches, to classify them according to the distribution and position of sediment along the transversal profile, and to obtain a discriminant function. To apply the methodology, 34 gravel beaches in the province of Alicante, Spain, were first classified visually into five different types: Type 1: Sand and gravel beaches, Type 2: Sand and gravel separated beaches, Type 3: Gravel and sand beaches, Type 4: Gravel and sand separated beaches, and Type 5: Pure gravel beaches. In addition, a major study was performed to reduce the number of variables because one of the concerns was to find the variables that characterize and classify the beaches. Thus, the 45 variables, grouped according to material characteristics, wave, boundary conditions, and geometry of the beach, were first reduced to 25 by making comparisons among them and the type of beach and were finally reduced to 14 using the discriminant method. Note the use of the important variable Posidonia oceanica in the Mediterranean area, which, because of the changes produced in the swell, was actively involved in the classification. Finally, the discriminant function obtained was validated.Aragones, L.; Lopez, I.; Villacampa, Y.; Serra Peris, JC.; Saval, J. (2018). New Methodology for the Classification of Gravel Beaches: Adjusted on Alicante (Spain). Journal of Coastal Research. 31(4):1023-1034. doi:10.2112/JCOASTRES-D-14-00140.1S1023103431

    Towards a Full Census of the Obscure(d) Vela Supercluster using MeerKAT

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    Recent spectroscopic observations of a few thousand partially obscured galaxies in the Vela constellation revealed a massive overdensity on supercluster scales straddling the Galactic Equator (l \sim 272.5deg) at cz18000cz \sim 18000km/s. It remained unrecognised because it is located just beyond the boundaries and volumes of systematic whole-sky redshift and peculiar velocity surveys - and is obscured by the Milky Way. The structure lies close to the apex where residual bulkflows suggest considerable mass excess. The uncovered Vela Supercluster (VSCL) conforms of a confluence of merging walls, but its core remains uncharted. At the thickest foreground dust column densities (|b| < 6 deg) galaxies are not visible and optical spectroscopy is not effective. This precludes a reliable estimate of the mass of VSCL, hence its effect on the cosmic flow field and the peculiar velocity of the Local Group. Only systematic HI-surveys can bridge that gap. We have run simulations and will present early-science observing scenarios with MeerKAT 32 (M32) to complete the census of this dynamically and cosmologically relevant supercluster. M32 has been put forward because this pilot project will also serve as precursor project for HI MeerKAT Large Survey Projects, like Fornax and Laduma. Our calculations have shown that a survey area of the fully obscured part of the supercluster, where the two walls cross and the potential core of the supercluster resides, can be achieved on reasonable time-scales (200 hrs) with M32.Comment: 10 pages, 3 figures, accepted for publication, Proceedings of Science, workshop on "MeerKAT Science: On the Pathway to the SKA", held in Stellenbosch 25-27 May 201
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