4,684 research outputs found

    Cosmic Chronometers: Constraining the Equation of State of Dark Energy. I: H(z) Measurements

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    We present new determinations of the cosmic expansion history from red-envelope galaxies. We have obtained for this purpose high-quality spectra with the Keck-LRIS spectrograph of red-envelope galaxies in 24 galaxy clusters in the redshift range 0.2 < z < 1.0. We complement these Keck spectra with high-quality, publicly available archival spectra from the SPICES and VVDS surveys. We improve over our previous expansion history measurements in Simon et al. (2005) by providing two new determinations of the expansion history: H(z) = 97 +- 62 km/sec/Mpc at z = 0.5 and H(z) = 90 +- 40 km/sec/Mpc at z = 0.8. We discuss the uncertainty in the expansion history determination that arises from uncertainties in the synthetic stellar-population models. We then use these new measurements in concert with cosmic-microwave-background (CMB) measurements to constrain cosmological parameters, with a special emphasis on dark-energy parameters and constraints to the curvature. In particular, we demonstrate the usefulness of direct H(z) measurements by constraining the dark- energy equation of state parameterized by w0 and wa and allowing for arbitrary curvature. Further, we also constrain, using only CMB and H(z) data, the number of relativistic degrees of freedom to be 4 +- 0.5 and their total mass to be < 0.2 eV, both at 1-sigma.Comment: Submitted to JCA

    Aprendizaje del Fibrobroncoscopio del Servicio de Anestesiología del Hospital Universitario de Getafe: Programa de aprendizaje

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    Las complicaciones más severas en Anestesiología son las relacionadas con la Vía Aérea, y una dificultad de intubación o ventilación del paciente originan una gran mórbida/mortalidad. En los últimos años, para mejorar la seguridad del paciente en este campo, ha habido una evolución muy importante en el manejo de la Vía Aérea Difícil (VAD). Las Sociedades internacionales más prestigiosas de este campo aconsejan en sus últimos trabajos y guías (ASA&nbsp;[Sociedad Americana de Vía Aérea Difícil] en el algoritmo del 2013, y la DAS&nbsp;[Difficult Airway Society] en el NAP4 y las guías de 2015….) aconsejan que todos los miembros del servicio de Anestesiología sean capaces de poder realizar una intubación con Fibroscopio (FOB) en paciente despierto cuando se precise. Es decir, en aquellos pacientes que tienen una intubación difícil conocida, y en los que administrarles anestesia general para realizar una intubación, perdiendo la respiración espontanea, supone un riesgo muy importante para ellos

    Decomposition and nitrogen mineralisation of two wild lupins (Leguminosae) species with potential as green manures

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    The amount of biomass produced by various native species of genus Lupinus (L.) growing in Mexico ranges from 2.9- 8.2 Mg/ha of dry matter, which can add up to 200 kg/ha of N to soil as green manure. However, information is scarce on the decomposition and mineralisation this biomass in the soil. The above-ground decomposition and N mineralisation of Lupinus mexicanus Cerv. ex Lag. and Lupinus rotundiflorus M.E. Jones species from Mexico using fine-mesh litter bags was evaluated. Litter bags containing 5 g of above-ground air-dried biomass at the vegetative and flowering stages were buried at a depth of 20 cm. Were dug up every 3 weeks over the course of 4 months, dried and re-weighed to determine the lost mass and total N by the Kjeldahl method. The largest decrease in residue mass occurred during the first 3 weeks of incubation. However, the lost mass was higher in younger green manure (75 days old) than in older plants (85 days old) after 18 weeks of exposure in the field. It was found that 60-75% of the total N in the plant material was released in the first 6 weeks. In L. rotundiflorus green manure, it was found that 79.14% of the initial N in the vegetative stage and 77.6% of N in the flowering stage was released 18 weeks after litter bag installation, whereas L. mexicanus were 74.6% and 74.7%, respectively. It was found that both decomposition and N mineralisation occurred quickly in the green manures evaluated

    Production performance, nutrient digestibility, and milk composition of dairy ewes supplemented with crushed sunflower seeds and sunflower seed silage in corn silage-based diets

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    This study determined production performance, nutrient digestibility, and milk composition of dairy ewes supplemented with crushed sunflower seeds (Helianthus annuus) and sunflower seed silage in corn silage-based diets. Six ewes were grouped in a double 3 × 3 Latin square design with three periods of 21 days. All treatments were based on ad libitum corn silage. Control diet was based on alfalfa hay (333 g/kg DM), sorghum grain (253 g/kg DM), triticale grain (200 g/kg DM), soybean meal (167 g /kg DM), and vitamin and mineral premix (47 g/kg DM). Sunflower seeds (SF) and sunflower seed silage (SFS) treatments consisted of alfalfa hay (333 g/kg DM), sorghum grain (267 g/kg DM), triticale grain (100 g/kg DM), soybean meal (167 g /kg DM), SF or SFS (87 g/kg DM) and vitamin and mineral premix (47 g/kg DM). Compared to control, SF and SFS increased intake and digestibility of fiber components, such as neutral detergent fiber (NDF) and acid detergent fiber (ADF). Body weight, nitrogen balance, milk yield, milk fat yield, milk protein yield, lactose yield and milk urea N were similar between treatments. Overall, results demonstrated that crushed sunflower seeds and ensiled seeds do not change significantly productive parameters of dairy sheep

    Single-nucleus RNA-seq2 reveals functional crosstalk between liver zonation and ploidy.

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    Funder: Cancer Research UKSingle-cell RNA-seq reveals the role of pathogenic cell populations in development and progression of chronic diseases. In order to expand our knowledge on cellular heterogeneity, we have developed a single-nucleus RNA-seq2 method tailored for the comprehensive analysis of the nuclear transcriptome from frozen tissues, allowing the dissection of all cell types present in the liver, regardless of cell size or cellular fragility. We use this approach to characterize the transcriptional profile of individual hepatocytes with different levels of ploidy, and have discovered that ploidy states are associated with different metabolic potential, and gene expression in tetraploid mononucleated hepatocytes is conditioned by their position within the hepatic lobule. Our work reveals a remarkable crosstalk between gene dosage and spatial distribution of hepatocytes

    Prospects in Constraining the Dark Energy Potential

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    We generalize to non-flat geometries the formalism of Simon et al. (2005) to reconstruct the dark energy potential. This formalism makes use of quantities similar to the Horizon-flow parameters in inflation, can, in principle, be made non-parametric and is general enough to be applied outside the simple, single scalar field quintessence. Since presently available and forthcoming data do not allow a non-parametric and exact reconstruction of the potential, we consider a general parametric description in term of Chebyshev polynomials. We then consider present and future measurements of H(z), Baryon Acoustic Oscillations surveys and Supernovae type 1A surveys, and investigate their constraints on the dark energy potential. We find that, relaxing the flatness assumption increases the errors on the reconstructed dark energy evolution but does not open up significant degeneracies, provided that a modest prior on geometry is imposed. Direct measurements of H(z), such as those provided by BAO surveys, are crucially important to constrain the evolution of the dark energy potential and the dark energy equation of state, especially for non-trivial deviations from the standard LambdaCDM model.Comment: 22 pages, 7 figures. 2 references correcte

    BDNF and NGF signalling in early phases of psychosis: relationship with inflammation and response to antipsychotics after a 1 year

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    Previous studies have indicated systemic deregulation of the proinflammatory or anti-inflammatory balance in individuals with first-episode psychosis (FEP) that persists 12 months later. To identify potential risk/protective factors and associations with symptom severity, we assessed possible changes in plasma levels of neurotrophins (brain-derived neurotrophic factor [BDNF] and nerve growth factor [NGF]) and their receptors in peripheral blood mononuclear cells (PBMCs). Expression of the 2 forms of BDNF receptors (active TrkB-FL and inactiveTrkB-T1) in PBMCs of FEP patients changed over time, TrkB-FL expression increasing by 1 year after diagnosis, while TrkB-T1 expression decreased. The TrkB-FL/TrkB-T1 ratio (hereafter FL/T1 ratio) increased during follow-up in the nonaffective psychosis group only, suggesting different underlying pathophysiological mechanisms in subgroups of FEP patients. Further, the expression of the main NGF receptor, TrkA, generally increased in patients at follow-up. After adjusting for potential confounders, baseline levels of inducible isoforms of nitric oxide synthase, cyclooxygenase, and nuclear transcription factor were significantly associated with the FL/T1 ratio, suggesting that more inflammation is associated with higher values of this ratio. Interestingly, the FL/T1 ratio might have a role as a predictor of functioning, a regression model of functioning at 1 year suggesting that the effect of the FL/T1 ratio at baseline on functioning at 1 year depended on whether patients were treated with antipsychotics. These findings may have translational relevance; specifically, it might be useful to assess the expression of TrkB receptor isoforms before initiating antipsychotic treatment in FEP
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