563 research outputs found

    Undecidability as solution to the problem of measurement: fundamental criterion for the production of events

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    In recent papers we put forth a new interpretation of quantum mechanics, colloquially known as ``the Montevideo interpretation''. This interpretation is based on taking into account fundamental limits that gravity imposes on the measurement process. As a consequence one has that situations develop where a reduction process is undecidable from an evolution operator. When such a situation is achieved, an event has taken place. In this paper we sharpen the definition of when and how events occur, more precisely we give sufficient conditions for the occurrence of events. We probe the new definition in an example. In particular we show that the concept of undecidability used is not ``FAPP'' (for all practical purposes), but fundamental.Comment: 10 pages, contributed to the Castagnino Festschrif

    Lyman break and UV-selected galaxies at z1z \sim 1 I. Stellar populations from ALHAMBRA survey

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    We take advantage of the exceptional photometric coverage provided by the combination of GALEX data in the UV and the ALHAMBRA survey in the optical and near-IR to analyze the physical properties of a sample of 1225 GALEX-selected Lyman break galaxies (LBGs) at 0.8z1.20.8 \lesssim z \lesssim 1.2 located in the COSMOS field. This is the largest sample of LBGs studied at that redshift range so far. According to a spectral energy distribution (SED) fitting with synthetic stellar population templates, we find that LBGs at z1z \sim 1 are mostly young galaxies with a median age of 341 Myr and have intermediate dust attenuation,  0.20\ \sim 0.20. Due to their selection criterion, LBGs at z1z \sim 1 are UV-bright galaxies and have high dust-corrected total SFR, with a median value of 16.9 Myr1M_\odot {\rm yr}^{-1}. Their median stellar mass is log(M/M)=9.74\log{\left(M_*/M_\odot \right)} = 9.74. We obtain that the dust-corrected total SFR of LBGs increases with stellar mass and the specific SFR is lower for more massive galaxies. Only 2% of the galaxies selected through the Lyman break criterion have an AGN nature. LBGs at z1z \sim 1 are mostly located over the blue cloud of the color-magnitude diagram of galaxies at their redshift, with only the oldest and/or the dustiest deviating towards the green valley and red sequence. Morphologically, 69% of LBGs are disk-like galaxies, with the fraction of interacting, compact, or irregular systems being much lower, below 12%. LBGs have a median effective radius of 2.5 kpc and bigger galaxies have higher total SFR and stellar mass. Comparing to their high-redshift analogues, we find evidence that LBGs at lower redshifts are bigger, redder in the UV continuum, and have a major presence of older stellar populations in their SEDs. However, we do not find significant difference in the distributions of stellar mass or dust attenuation.Comment: Accepted for publication in MNRA

    Galaxy classification: deep learning on the OTELO and COSMOS databases

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    Context. The accurate classification of hundreds of thousands of galaxies observed in modern deep surveys is imperative if we want to understand the universe and its evolution. Aims. Here, we report the use of machine learning techniques to classify early- and late-type galaxies in the OTELO and COSMOS databases using optical and infrared photometry and available shape parameters: either the Sersic index or the concentration index. Methods. We used three classification methods for the OTELO database: 1) u-r color separation , 2) linear discriminant analysis using u-r and a shape parameter classification, and 3) a deep neural network using the r magnitude, several colors, and a shape parameter. We analyzed the performance of each method by sample bootstrapping and tested the performance of our neural network architecture using COSMOS data. Results. The accuracy achieved by the deep neural network is greater than that of the other classification methods, and it can also operate with missing data. Our neural network architecture is able to classify both OTELO and COSMOS datasets regardless of small differences in the photometric bands used in each catalog. Conclusions. In this study we show that the use of deep neural networks is a robust method to mine the cataloged dataComment: 20 pages, 10 tables, 14 figures, Astronomy and Astrophysics (in press

    Newborn screening for medium-chain acyl-CoA dehydrogenase deficiency: regional experience and high incidence of carnitine deficiency

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    Background Medium-chain acyl-CoA dehydrogenase deficiency (MCADD) is the most common inherited defect in the mitochondrial fatty acid oxidation pathway, resulting in significant morbidity and mortality in undiagnosed patients. Newborn screening (NBS) has considerably improved MCADD outcome, but the risk of complication remains in some patients. The aim of this study was to evaluate the relationship between genotype, biochemical parameters and clinical data at diagnosis and during follow-up, in order to optimize monitoring of these patients. Methods We carried out a multicenter study in southwest Europe, of MCADD patients detected by NBS. Evaluated NBS data included free carnitine (C0) and the acylcarnitines C8, C10, C10:1 together with C8/C2 and C8/C10 ratios, clinical presentation parameters and genotype, in 45 patients. Follow-up data included C0 levels, duration of carnitine supplementation and occurrence of metabolic crises. Results C8/C2 ratio and C8 were the most accurate biomarkers of MCADD in NBS. We found a high number of patients homozygous for the prevalent c.985A > G mutation (75%). Moreover, in these patients C8, C8/C10 and C8/C2 were higher than in patients with other genotypes, while median value of C0 was significantly lower (23 μmol/L vs 36 μmol/L). The average follow-up period was 43 months. To keep carnitine levels within the normal range, carnitine supplementation was required in 82% of patients, and for a longer period in patients homozygotes for the c.985A>G mutation than in patients with other genotypes (average 31 vs 18 months). Even with treatment, median C0 levels remained lower in homozygous patients than in those with other genotypes (14 μmol/L vs 22 μmol/L). Two patients died and another three suffered a metabolic crisis, all of whom were homozygous for the c.985 A>G mutation. Conclusions Our data show a direct association between homozygosity for c.985A>G and lower carnitine values at diagnosis, and a higher dose of carnitine supplementation for maintenance within the normal range. This study contributes to a better understanding of the relationship between genotype and phenotype in newborn patients with MCADD detected through screening which could be useful in improving follow-up strategies and clinical outcome

    The OTELO survey. A case study of [O III]4959,5007 emitters at <z> = 0.83

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    The OTELO survey is a very deep, blind exploration of a selected region of the Extended Groth Strip and is designed for finding emission-line sources (ELSs). The survey design, observations, data reduction, astrometry, and photometry, as well as the correlation with ancillary data used to obtain a final catalogue, including photo-z estimates and a preliminary selection of ELS, were described in a previous contribution. Here, we aim to determine the main properties and luminosity function (LF) of the [O III] ELS sample of OTELO as a scientific demonstration of its capabilities, advantages, and complementarity with respect to other surveys. The selection and analysis procedures of ELS candidates obtained using tunable filter (TF) pseudo-spectra are described. We performed simulations in the parameter space of the survey to obtain emission-line detection probabilities. Relevant characteristics of [O III] emitters and the LF([O III]), including the main selection biases and uncertainties, are presented. A total of 184 sources were confirmed as [O III] emitters at a mean redshift z=0.83. The minimum detectable line flux and equivalent width (EW) in this ELS sample are \sim5 ×\times 1019^{-19} erg s1^{-1} cm2^{2} and \sim6 \AA, respectively. We are able to constrain the faint-end slope (α=1.03±0.08\alpha = -1.03\pm0.08) of the observed LF([O III]) at z=0.83. This LF reaches values that are approximately ten times lower than those from other surveys. The vast majority (84\%) of the morphologically classified [O III] ELSs are disc-like sources, and 87\% of this sample is comprised of galaxies with stellar masses of M_\star << 1010^{10} M_{\odot}.Comment: v1: 16 pages, 6 figures. Accepted in Astronomy \& Astrophysics. v2: Author added in metadat

    Physical properties of Lyman-alpha emitters at z0.3z\sim 0.3 from UV-to-FIR measurements

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    The analysis of the physical properties of low-redshift Lyα\alpha emitters (LAEs) can provide clues in the study of their high-redshift analogues. At z0.3z \sim 0.3, LAEs are bright enough to be detected over almost the entire electromagnetic spectrum and it is possible to carry out a more precise and complete study than at higher redshifts. In this study, we examine the UV and IR emission, dust attenuation, SFR and morphology of a sample of 23 GALEX-discovered star-forming (SF) LAEs at z0.3z \sim 0.3 with direct UV (GALEX), optical (ACS) and FIR (PACS and MIPS) data. Using the same UV and IR limiting luminosities, we find that LAEs at z0.3z\sim 0.3 tend to be less dusty, have slightly higher total SFRs, have bluer UV continuum slopes, and are much smaller than other galaxies that do not exhibit Lyα\alpha emission in their spectrum (non-LAEs). These results suggest that at z0.3z \sim 0.3 Lyα\alpha photons tend to escape from small galaxies with low dust attenuation. Regarding their morphology, LAEs belong to Irr/merger classes, unlike non-LAEs. Size and morphology represent the most noticeable difference between LAEs and non-LAEs at z0.3z \sim 0.3. Furthermore, the comparison of our results with those obtained at higher redshifts indicates that either the Lyα\alpha technique picks up different kind of galaxies at different redshifts or that the physical properties of LAEs are evolving with redshift.Comment: Accepted for publication in Ap

    PACS-Herschel FIR detections of Lyman-alpha emitters at 2.0<z<3.5

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    In this work we analyze the physical properties of a sample of 56 spectroscopically selected star-forming (SF) Lyα\alpha emitting galaxies at 2.0\lesssimz\lesssim3.5 using both a spectral energy distribution (SED) fitting procedure from rest-frame UV to mid-IR and direct 160μ\mum observations taken with the Photodetector Array Camera & Spectrometer (PACS) instrument onboard \emph{Herschel Space Observatory}. We define LAEs as those Lyα\alpha emitting galaxies whose rest-frame Lyα\alpha equivalent widths (Lyα\alpha EWrestframe_{rest-frame}) are above 20\AA, the typical threshold in narrow-band searches. Lyα\alpha emitting galaxies with Lyα\alpha EWrestframe_{rest-frame} are called non-LAEs. As a result of an individual SED fitting for each object, we find that the studied sample of LAEs contains galaxies with ages mostly below 100Myr and a wide variety of dust attenuations, SFRs, and stellar masses. The heterogeneity in the physical properties is also seen in the morphology, ranging from bulge-like galaxies to highly clumpy systems. In this way, we find that LAEs at 2.0\lesssimz\lesssim3.5 are very diverse, and do not have a bimodal nature, as suggested in previous works. Furthermore, the main difference between LAEs and non-LAEs is their dust attenuation, because LAEs are not as dusty as non-LAEs. On the FIR side, four galaxies of the sample (two LAEs and two non-LAEs) have PACS-FIR counterparts. Their total IR luminosity place all of them in the ULIRG regime and are all dusty objects, with A1200_{1200}\gtrsim4mag. This is an indication from direct FIR measurements that dust and Lyα\alpha emission are not mutually exclusive. This population of red and dusty LAEs is not seen at z\sim0.3, suggesting an evolution with redshift of the IR nature of galaxies selected via their Lyα\alpha emission.Comment: Accepted for publication in A&

    Un nuevo concepto de la gastronomía desde la bioeconomía y la actividad académica

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    El proyecto “Ciencia y arte en gastronomía: botánica gastronómica y gastronomía molecular” se está desarrollando con el objetivo de establecer y organizar el intercambio de conocimientos y negocio en este ámbito. Con este objetivo se pretende aunar el conocimiento científico con la salud y el bienestar social desde la perspectiva bioeconómica promoviendo la creación de riqueza y trabajo. El proyecto forma parte de los cursos especializados que la Universidad Complutense de Madrid oferta con el animo de incrementar el conocimiento y desarrollar competencias personales y profesionales. El programa responde a la demanda social proporcionando una formación con inmediata proyección profesional mediante el establecimiento de un nexo directo entre la actividad académica y la realidad social.Universidad de Sevilla. Cristalografía, Mineralogía y Química Agrícola The project "Science and art in gastronomy: gastronomic botany and molecular gastronomy" is being developed with the aim to establish and organize the exchange of knowledge and business in this area. In this way we are working to join the scientific knowledge to the health and the social well-being, without losing the current perspective from the bioeconomy which look forward the generation of wealth and work. The project belongs to specialized courses offered by The Complutense University of Madrid which aim is to update the knowledge and develop personal and professional competitions. These programs answer to a social demand on providing formation with professional immediate projection establishing a direct relation between the academic activity and the social reality
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