868 research outputs found

    Molecular characterization of dissolved organic matter linked to microbial (Bacteria and Archaea) diversity in the main water masses of the Eastern North Atlantic Ocean

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    The microbe-dissolved organic matter (DOM) interactions include microbial uptake and DOM reworking and release, affecting the composition of the heterogeneous DOM pool. In turns, this distinct DOM composition can select for microbial assemblages. We investigated the diversity of microbial (both Bacteria and Archaea) communities (combining Illumina tag sequencing of 16S rRNA gen -amplicon sequencing variants, ASVs- and metagenomics) and the chemodiversity of dissolved organic molecules (extracted by solid phase extraction and analyzed by Fourier Transform Ion Cyclotron Resonance Mass Spectrometry, FT-ICR-MS) in the Eastern North Atlantic Ocean off the Galician coast (43oN, 9o-15oW). Sampling ranged from 100 m to 5000 m, thereby encompassing a wide variety of water masses with contrasting origins and different aging. Applying diversity ecological metrics to both organic compounds and ASVs, we found that microbial diversity and richness were negatively correlated with DOM concentration and chemo-diversity. Besides, our results demonstrated the link between this trend and water mass aging, which enhances biosphere taxonomic diversity but reduces molecular variety. DOM diversity, decreasing along the water mass aging gradient, would likely reflect the persistence of the most refractory molecules, generated as by- product of the DOM degradation by microbes. In two PCoAs based on the metagenomic data, combined PCoA axis 1 and PCoA axis 2, explained the 80% and 20% of the microbial gene ́s structural variability among water masses. The oldest water masses, originated at high latitudes, such as NADW and LDW, were associated to higher abundance of genes involved in metabolism of aromatic compound. Intermediate waters such as ENACWst were related to sulphur/iron/phosphorous metabolism related genes. Surface waters were linked to genes involved in photosynthesis, autotrophy and cell division. Taken together, the observed increase of DOM homogenization along water mass aging was associated to differences in the functional diversity of microbial communities

    Calibration and performance tests of detectors for laser-accelerated protons

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    We present the calibration and performance tests carried out with two detectors for intense proton pulses accelerated by lasers. Most of the procedures were realized with proton beams of 0.46-5.60 MeV from a tandem accelerator. One approach made use of radiochromic films, for which we calibrated the relation between optical density and energy deposition over more than three orders of magnitude. The validity of these results and of our analysis algorithms has been confirmed by controlled irradiation of film stacks and reconstruction of the total beam charge for strongly non-uniform beam profiles. For the spectral analysis of protons from repeated laser shots, we have designed an online monitor based on a plastic scintillator. The resulting signal from a photomultiplier directly measured on a fast oscilloscope is especially useful for time-of-flight applications. Variable optical filters allow for suppression of saturation and an extension of the dynamic range. With pulsed proton beams we have tested the detector response to a wide range of beam intensities from single particles to 3 ×105 protons per 100 ns time interval.Project funded by the Spanish Ministry of Economy and Competitiveness and co-funded with FEDER's funds within the INNPACTO 2011 program under Grant No. IPT-2011-0862-900000. This work was supported by the Spanish Plan Nacional de Investigacion Cientifica, Desarrollo e Innovacion Tecnologica (I+D+i) under Grant No. TEC 2013-48036-C3-1-R and the Valencian Local Government under Grants PROMETEOII/2013/010 and ISIC 2011/013. The work of A. J. Gonzalez is financed by CSIC with a JAE-Doc contract under Junta de Ampliacion de Estudios program, cofinanced by the European Social Fund.Peer Reviewe

    Time-of-Flight Detector for the Characterisation of Laser-Accelerated Protons

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    [Otros] Lasers of ultra-high intensity focused on thin targets can form plasmas and release large numbers of charged particles with kinetic energies in the MeV region. The characterization of the accelerated particles requires suitable detectors. We present a time-of-flight detector based on a plastic scintillator optimized for the spectral analysis of laser-accelerated protons. All details of the detector layout are adapted to the expected properties of the proton beam. Particle energies will be separated by the time-of-flight technique over 200 cm path length. The active area (25 mm width) corresponds to a few mrad opening angle. With 5 mm thickness the detector is capable of absorbing protons up to 22.5 MeV. A very thin, aluminized mylar foil shields the scintillator from outer light while absorbing very little particle energy. The scintillation photons are measured with a photomultiplier tube coupled through a bundle of optical fibres. The coupling of these fibres via a PMMA light guide has been previously optimized in simulations with Litrani. A critical aspect of the detection of virtually large numbers of protons emitted in femtosecond pulses is the saturation of the PMT. The latter can be avoided by use of appropriate optical filters. With these the effective dynamic range starts from single particles over several orders of magnitude. Our time-of-flight detector has been calibrated at the Spanish National Accelerator Centre at Sevilla. Proton beams from 0.46 to 5.6 MeV from a tandem accelerator have been used to measure the relation between particle energy and pulse heights. Further tests have been performed with a pulsed electron beam to simulate many-particle hits.Project funded by the Spanish Ministry of Economy and Competitiveness and co-funded with FEDER¿s funds within the INNPACTO 2011 program, Grant No. IPT-2011-0862- 900000. This work was supported by the Spanish Plan Nacional de Investigacion Científica, Desarrollo e Innovacion Tecnológica (I+D+i) under Grant No. FIS2010-21216-CO2-01 and the Valencian Local Government under Grants PROMETEOII/2013/010 and ISIC 2011/013Seimetz, M.; Bellido, P.; Soriano, A.; Huertas, C.; García Lopez, J.; Jimenez-Ramos, MC.; Fernandez, B.... (2013). Time-of-Flight Detector for the Characterisation of Laser-Accelerated Protons. IEEE. 25-28. https://doi.org/10.1109/NSSMIC.2013.6829804S252

    Dosimetric Calibration of Radiochromic Film For Laser-accelerated Proton Beams

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    [Otros] When an ultra-intense and ultra-short laser pulse interacts with solid matter a fraction of the laser pulse can be converted into kinetic energy of a beam of charged particles. Radiochromic film (RCF), widely used as radiation detector in the field of conventional radiotherapy, can be used as detector for laser-accelerated protons. If used in stack configuration it is a useful and versatile tool to obtain 2D spatial distribution and energetic information of proton beams. In order to obtain dosimetric information from RCF it must be properly calibrated. Irradiating film pieces under well known conditions allows us to establish a relation between the optical density (OD) of the radiochromic film, which is measured through a flat bed scanner operating in transmission mode, and the deposited energy in the active layer. A calibration curve over a large dynamic range (3 orders of magnitude) has been obtained for few MeV protons. Our calibration process has been performed at the Spanish National Accelerator Center at Sevilla. We have irradiated several areas of a single RCF with a constant 50 pA beam current and fixed 4 MeV energy from a 3 MV tandem accelerator. We have calculated the deposited energy in the films under the same conditions. We demonstrate that this technique can be used to measure the spectrum and total energy of a laser-accelerated mixed-energy proton beam. This detector has been calibrated for a near future application at the Center of Pulsed, Ultra-short, Ultra-intense Lasers (CLPU) at Salamanca (Spain). We present the calibration procedure and results, the design optimization, and a comparison with similar experiments.Project funded by the Spanish Ministry of Economy and Competitiveness and co-funded with FEDERs funds within the INNPACTO 2011 program. This work was supported by the Spanish Plan Nacional de Investigacion Cientifica, Desarrollo e InnovacionTecnologica (I+D+i) under Grant No. FIS2010-21216-CO2-01 and the Valencian Local Government under Grants PROMETEOII/2013/010 and ISIC 2011/013.Bellido, P.; Seimetz, M.; Soriano, A.; Huertas, C.; García Lopez, J.; Jimenez-Ramos, MC.; Fernandez, B.... (2013). Dosimetric Calibration of Radiochromic Film For Laser-accelerated Proton Beams. IEEE. 20-23. https://doi.org/10.1109/NSSMIC.2013.6829806S202

    Calibration and Performance Tests of Detectors for Laser-Accelerated Protons

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    “©2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.”We present the calibration and performance tests carried out with two detectors for intense proton pulses accelerated by lasers. Most of the procedures were realized with proton beams of 0.46-5.60 MeV from a tandem accelerator. One approach made use of radiochromic films, for which we calibrated the relation between optical density and energy deposition over more than three orders of magnitude. The validity of these results and of our analysis algorithms has been confirmed by controlled irradiation of film stacks and reconstruction of the total beam charge for strongly non-uniform beam profiles. For the spectral analysis of protons from repeated laser shots, we have designed an online monitor based on a plastic scintillator. The resulting signal from a photomultiplier directly measured on a fast oscilloscope is especially useful for time-of-flight applications. Variable optical filters allow for suppression of saturation and an extension of the dynamic range. With pulsed proton beams we have tested the detector response to a wide range of beam intensities from single particles 3 x 10(5) to protons per 100 ns time interval.Project funded by the Spanish Ministry of Economy and Competitiveness and co-funded with FEDER's funds within the INNPACTO 2011 program under Grant No. IPT-2011-0862-900000. This work was supported by the Spanish Plan Nacional de Investigacion Cientifica, Desarrollo e Innovacion Tecnologica (I+D+i) under Grant No. TEC 2013-48036-C3-1-R and the Valencian Local Government under Grants PROMETEOII/2013/010 and ISIC 2011/013. The work of A. J. Gonzalez is financed by CSIC with a JAE-Doc contract under Junta de Ampliacion de Estudios program, cofinanced by the European Social Fund.Seimetz, M.; Bellido, P.; Soriano Asensi, A.; García López, J.; Jiménez-Ramos, M.; Fernández, B.; Conde Castellanos, PE.... (2015). Calibration and Performance Tests of Detectors for Laser-Accelerated Protons. IEEE Transactions on Nuclear Science. 62(6):3216-3224. https://doi.org/10.1109/TNS.2015.2480682S3216322462

    The state of the Martian climate

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    60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

    Revista de Vertebrados de la Estación Biológica de Doñana

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    Página 298 con error de impresiónEstudio cariológico en dos especies de Serránidos del Mediterráneo (Peces: PerciformesRelaciones morfométricas de Atherina boyeri Risso (Pisces: Atherinidae) de la laguna de Zoñar (Córdoba, España)Contribución al conocimiento de la biometríay osteología de Barbus barbus bocagei, Steindachner, 1866 (Pisces: CyprinidaeLa actividad de la salamandra, Salamandra salamandra (L.), en Galicia.Estudios sobre el sapo corredor (Bufo calamita) en el Sur de España.1. BiometríaEstudios sobre el sapo corredor (Bufo calamita) en el Sur de España. II. AlimentaciónBiología de la reproducción de Rana iberica Boulenger 1879 en zonas simpátridas con Rana temporaria Linneo, 1758Nuevos datos sobre la distribución geográfica de Lacerta monticola cantabrica Mertens, 1929. (Sauria, lacertidae).Datos sobre Lacerta monticola Boulenger, 1905 (Saurio: lacertidae)en el oeste del Sistema Central.Nueva especie de Anolis (lacertilia, Iguanidae) para CubaEtograma cuantificado del cortejo en Falco naumannOntogénesis del comportamiento predador en Falco naumanniContaminación xenobiótica del Parque Nacional de Doñana. 1. Residuos de insecticidas organoclorados, bifenilos policlorados y mercurio en anseriformes y gruiformesReproducción del críalo (Clamator glandarius) en Sierra Morena CentraNidificación de Picus viridis en taludes de arcilla en Ramblas de Guadix (Granada)Comportamiento del calamón Porphyrio porphyrio (Linnaeus, 1758) en Doñana, Marismas del GuadalquiviBiología y ecología de la malvasía (Oxyura leucocephala) en Andalucía.On the differential diet of Carnivora in islands:a method for analysing it and a particular case.Notas sobre la distribución pasada y actual del meloncillo Herpestes ichneumon (L.) en la Península IbéricaEstructuración de las interacciones en una camada de lobos (Canís lupus)Nuevos datos sobre la distribución del Cottus gobio L. (pisces, cottidae) en EspañaSobre la alimentación de Callopistes maculatus (Reptilia,teiidaeObservación de Lacerta lepida depredando un nido de Alectoris rufaNueva cita del galápago leproso Mauremys leprosa (Scheigger, 1812) en los pirineosPrimera cita de Psammodromus hispanicus (Fitzinger) para GaliciaSobre la presencia de Gallotia (=Lacerta) atlantica (Peters y Doria, 1882) en Gran CanariaNota sobre las Lacerta monticola Boulenger, 1905 de las zonas del norte de GaliciaPrimeras notas herpetológicas de la provincia de Soria.Datos sobre selección de hábitat y ecología alimenticia del porrón pardo (Aythya nyroca)Probable nueva área de cría del pechiazul (Luscinia svecica cyanecula) en el sistema central. PerisPredación de Falco peregrinus y Falco subbuteo sobre quirópterosResultados de la producción de Oxyura leucocephala en el año 1981 en las lagunas de Zóñar y el rincónAnálisis de la dieta de Tyto alba en un medio árido antropógeno de los alrededores de Almería¿Son Eudocimus ruber y E. albus distintas especies?EL Estornino pinto (Sturnus vulgaris) en Canarias: nueva especie nidifiante en el archipiélagoDatos sobre la alimentación otoñal del cárabo (Strix aluco) en la sierra de CádizObservación primaveral de rapaces y otras aves en el páramo del estado de Mérida (Venezuela).Murciélago hematófago (Desmodus rotundus) parasitando a un chigüire (Hidrochoerus hydrochaeris)Observaciones sobre la reproducción del zacatuche o teporinho Romerolagus diazi (Mammalia: lagomorpha)Estudio electroforético de hemoglobinas y esterasas sanguíneas en Rhinolophus ferrumequinum (Chiroptera: rhinolophidae) y de hemoglobinas en Tadaria taeniotis (chiroptera: molossidae)Peer reviewe

    Study of the scattering of halo nuclei around the Coulomb barrier

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    During the past ten years the present collaboration has carried out several experiments related with the study of radioactive nuclei. One of the topics in which we have centered our research, is the scattering of halo nuclei at energies around the Coulomb barrier. As part of this study, we present in this work a review of the results obtained from the scattering of 6He, 11Be and 11Li. The presence of a >halo> in these exotic nuclei is found to have a striking effect on the dynamics of these reactions, making their study an interesting experimental problem and a challenge for existing reaction theories.Peer Reviewe

    Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

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    The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality
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