1,474 research outputs found

    Necesidad de formación en el mercado de trabajo español: composición del empleo y estructura productiva

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    Este trabajo estudia las intensas transformaciones que se han producido en la composición del empleo español por niveles de educación y por categoría profesional. Mediante una técnica de descomposición “shift-share” se desagregan los efectos inputados al cambio técnico sesgado y al cambio técnico desigual, y se advierte que, en la segunda mitad de los noventa, se ha producido una ruptura con la pauta de comportamiento anterior. En efecto, a partir de 1995, el incremento de participación total del empleo cualificado ha venido determinado con mucha mayor intensidad que en períodos anteriores por el cambio técnico sesgado. Cuando, en cambio, esta influencia se examina desde la perspectiva de la recomposición del empleo por categoría profesional se observa que ha sido mucho menor. Ello permite introducir, aunque de manera muy preliminar, la hipótesis de sobreeducación en el mercado de trabajo español, que según los resultados obtenidos y como es de esperar, sólo afectaría a los colectivos más formados con relación a las categorías profesionales con empleos no manuales.empleo, cambio técnico, educación, ocupaciones, sobreeducación.

    Impact of a mouth parasite in a marine fish differs between geographical areas

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    Considerable variation exists in parasite virulence and host tolerance which may have a genetic and/or environmental basis. In this article, we study the effects of a striking, mouth-dwelling, blood-feeding isopod parasite (Ceratothoa italica) on the life history and physiological condition of two Mediterranean populations of the coastal fish, Lithognathus mormyrus. The growth and hepatosomatic index (HSI) of fish in a heavily human-exploited population were severely impacted by this parasite, whereas C. italica showed negligible virulence in fish close to a marine protected area. In particular, for HSI, the parasite load explained 34.4% of the variation in HSI in the exploited population, whereas there was no significant relationship (0.3%) between parasite load and HSI for fish in the marine protected area. Both host and parasite populations were not differentiated for neutral genetic variation and were likely to exchange migrants. We discuss the role of local genetic adaptation and phenotypic plasticity, and how deteriorated environmental conditions with significant fishing pressure can exacerbate the effects of parasitism. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 105, 842–852

    ML 3.0 smoothed aggregation user's guide.

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    ML is a multigrid preconditioning package intended to solve linear systems of equations Az = b where A is a user supplied n x n sparse matrix, b is a user supplied vector of length n and x is a vector of length n to be computed. ML should be used on large sparse linear systems arising from partial differential equation (PDE) discretizations. While technically any linear system can be considered, ML should be used on linear systems that correspond to things that work well with multigrid methods (e.g. elliptic PDEs). ML can be used as a stand-alone package or to generate preconditioners for a traditional iterative solver package (e.g. Krylov methods). We have supplied support for working with the AZTEC 2.1 and AZTECOO iterative package [15]. However, other solvers can be used by supplying a few functions. This document describes one specific algebraic multigrid approach: smoothed aggregation. This approach is used within several specialized multigrid methods: one for the eddy current formulation for Maxwell's equations, and a multilevel and domain decomposition method for symmetric and non-symmetric systems of equations (like elliptic equations, or compressible and incompressible fluid dynamics problems). Other methods exist within ML but are not described in this document. Examples are given illustrating the problem definition and exercising multigrid options

    Necesidad de formación en el mercado de trabajo español : composición del empleo y estructura productiva

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    Este trabajo estudia las intensas transformaciones que se han producido en la composición del empleo español por niveles de educación y por categoría profesional. Mediante una técnica de descomposición shift-share se desagregan los efectos inputados al cambio técnico sesgado y al cambio técnico desigual, y se advierte que, en la segunda mitad de los noventa, se ha producido una ruptura con la pauta de comportamiento anterior. En efecto, a partir de 1995, el incremento de participación total del empleo cualificado ha venido determinado con mucha mayor intensidad que en períodos anteriores por el cambio técnico sesgado. Cuando, en cambio, esta influencia se examina desde la perspectiva de la recomposición del empleo por categoría profesional se observa que ha sido mucho menor. Ello permite introducir, aunque de manera muy preliminar, la hipótesis de sobreeducación en el mercado de trabajo español, que según los resultados obtenidos y como es de esperar, sólo afectaría a los colectivos más formados con relación a las categorías profesionales con empleos no manuales

    Enhanced fluorescence by metal nanospheres on metal substrates

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    We investigate the metal enhanced fluorescence by silver nanospheres on a thin silver substrate. Experimental measurements for core/shell colloidal nanocrystals embedded in a polymer matrix show a fluorescence enhancement factor of about 9. We apply the discrete dipole approximation method to describe the local-field enhancement factor (LFEF). We find that the observed fluorescence enhancement is related to the broad LFEF profile induced by the substrate

    Rectification in supramolecular zinc porphyrin/fulleropyrrolidine dyads self-organized on gold(111).

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    Self-assembled donor/acceptor dyads are of current interest as they are biomimetic to the natural photosynthetic conversion system. Herein, we present an ultrahigh-vacuum scanning tunneling microscopy and scanning tunneling spectroscopy (UHV-STM/STS) study of ex situ self-assembled supramolecular dyads consisting of fulleropyrrolidines (PyC 2 C 60 ) axially ligated to zinc(II) tetraphenylporphyrin (ZnTPP), self organized on a 4-aminothiophenol (4-ATP) self-assembled monolayer on gold-(111). These dyads show both bias-polarity-dependent apparent height in STM images and highly rectifying behavior in tunneling spectroscopy. First-principles density functional theory calculations clarify the conformational and electronic properties of the 4-ATP/ZnTPP/PyC 2 C 60 system. Interestingly, we find easier tunneling for electrons moving from the acceptor side of the dyads to the donor side, in the inverse-rectifying sense with respect to previously reported molecular rectifiers. Such behavior cannot be explained as an elastic resonant tunneling process, but it can by using a model based on the Aviram-Ratner mechanism

    Repeatability of quantitative FDG-PET/CT and contrast-enhanced CT in recurrent ovarian carcinoma: test-retest measurements for tumor FDG uptake, diameter, and volume.

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    PURPOSE: Repeatability of baseline FDG-PET/CT measurements has not been tested in ovarian cancer. This dual-center, prospective study assessed variation in tumor 2[18F]fluoro-2-deoxy-D-glucose (FDG) uptake, tumor diameter, and tumor volume from sequential FDG-PET/CT and contrast-enhanced computed tomography (CECT) in patients with recurrent platinum-sensitive ovarian cancer. EXPERIMENTAL DESIGN: Patients underwent two pretreatment baseline FDG-PET/CT (n = 21) and CECT (n = 20) at two clinical sites with different PET/CT instruments. Patients were included if they had at least one target lesion in the abdomen with a standardized uptake value (SUV) maximum (SUVmax) of ≥ 2.5 and a long axis diameter of ≥ 15 mm. Two independent reading methods were used to evaluate repeatability of tumor diameter and SUV uptake: on site and at an imaging clinical research organization (CRO). Tumor volume reads were only performed by CRO. In each reading set, target lesions were independently measured on sequential imaging. RESULTS: Median time between FDG-PET/CT was two days (range 1-7). For site reads, concordance correlation coefficients (CCC) for SUVmean, SUVmax, and tumor diameter were 0.95, 0.94, and 0.99, respectively. Repeatability coefficients were 16.3%, 17.3%, and 8.8% for SUVmean, SUVmax, and tumor diameter, respectively. Similar results were observed for CRO reads. Tumor volume CCC was 0.99 with a repeatability coefficient of 28.1%. CONCLUSIONS: There was excellent test-retest repeatability for FDG-PET/CT quantitative measurements across two sites and two independent reading methods. Cutoff values for determining change in SUVmean, SUVmax, and tumor volume establish limits to determine metabolic and/or volumetric response to treatment in platinum-sensitive relapsed ovarian cancer.This study was funded by Merck and Co.This version is the author accepted manuscript. The OnlineFirst version of this article can be found on the publisher's website at: http://clincancerres.aacrjournals.org/content/20/10/2751.full.pdf+htm

    Whole-genome sequencing analysis of semi-supercentenarians

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    Extreme longevity is the paradigm of healthy aging as individuals who reached the extreme decades of human life avoided or largely postponed all major age-related diseases. In this study, we sequenced at high coverage (90X) the whole genome of 81 semi-supercentenarians and supercentenarians [105+/110+] (mean age: 106.6 ± 1.6) and of 36 healthy unrelated geographically matched controls (mean age 68.0 ± 5.9) recruited in Italy. The results showed that 105+/110+ are characterized by a peculiar genetic background associated with efficient DNA repair mechanisms, as evidenced by both germline data (common and rare variants) and somatic mutations patterns (lower mutation load if compared to younger healthy controls). Results were replicated in a second independent cohort of 333 Italian centenarians and 358 geographically matched controls. The genetics of 105+/110+ identified DNA repair and clonal haematopoiesis as crucial players for healthy aging and for the protection from cardiovascular events

    Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

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    The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
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