35 research outputs found

    Experimentos numéricos con diferentes resoluciones de episodios de lluvias fuertes y ciclogénesis de Argelia

    Get PDF
    Se estudia la dependencia crucial de la resolución en el modelo de área limitada del INM para simular episodios de lluvias fuertes asociados con ciclogénesis de Argelia. Estos fenómenos caen ya dentro de la mesoscala por lo que la resolución operativa del modelo es inadecuada para su simulación

    Resultados de experimentos numéricos en casos de episodios de lluvias fuertes en el Mediterráneo

    Get PDF
    Ponencia presentada en: II Simposio Nacional de Predictores, celebrado en 1990 en Madrid los días 20-22 de noviembr

    Influencia de la orografía y la condensación en la ciclogénesis de Argelia

    Get PDF
    Ponencia presentada en: I Simposio Nacional de Predictores, celebrado en 1989 en Madri

    Patrimonio geopaleontológico de los depósitos aluviales situados sobre la terraza +28 m del Jarama. Nuevos datos micropaleontológicos y cronológicos (Solar de la Real Fábrica de Paños de San Fernando de Henares)

    Get PDF
    Trabajo presentado en la Reunión de Arqueología Madrileña, celebrada en Alcalá de Henares el 20 y 21 de noviembre de 2014.[ES] Durante los trabajos de vigilancia de los movimientos de tierras asociados a la obra de la construcción de viviendas en el solar de la Real Fábrica de Paños (en adelante RFP) de San Fernando de Henares se documentaron materiales geológicos de edad miocena y cuaternaria con un contacto lateral dinámico entre ellos, constituido por una falla extensional de dirección norte-sur. En los niveles cuaternarios se registraron numerosos restos paleontológicos y algunas piezas de industria lítica. Según los estudios preliminares geomorfológicos y de macromamíferos (Tapias y Arango 2008; Yravedra et al. 2008; Dones et al. 2011) se asignó una cronología genérica de Pleistoceno Medio, confirmada por la datación obtenida por racemización de aminoácidos de un molar de Equus caballus (304 ka). En este trabajo se aportan nuevos datos a partir de la revisión y estudio de los restos de micromamíferos recuperados en la unidad 3. La presencia de Microtus brecciensis y M. arvalis en la base de los depósitos aluviales posibilita su adscripción cronológica al Pleistoceno Medio avanzado (MIS 8 o MIS 6).[EN] During the monitoring of the movements of land associated with the work of the construction of homes in the Solar of the Royal Factory of Cloths of San Fernando de Henares, some geological materials of Miocene and Quaternary age were documented. Numerous paleontological remains and some stone tools have been registered in these quaternary levels. According to geomorphological preliminary studies and macromammals (Tapias y Arango 2008; Yravedra et al. 2008; Dones et al. 2011) a generic Middle Pleistocene chronology was assigned. This was confirmed by the aminoacids racemization dating of Equus caballus molar (304 ka) This paper provides new data of the remains of micromammals recovered. The faunal assemblage, with Microtus brecciensis and M arvalis found at the base of the alluvial deposits, has allowed reviewing previous studies. It could be more specific on the geochronological and paleoenviromental contextualization of remains and materials that could be assigned to advanced Middle Pleistocene (MIS 8 or MIS 6).Peer reviewe

    Large-scale ocean connectivity and planktonic body size

    Get PDF
    Villarino, Ernesto ... et al.-- 13 pages, 5 figures, 5 tables, supplementary material https://dx.doi.org/10.1038/s41467-017-02535-8Global patterns of planktonic diversity are mainly determined by the dispersal of propagules with ocean currents. However, the role that abundance and body size play in determining spatial patterns of diversity remains unclear. Here we analyse spatial community structure - β-diversity - for several planktonic and nektonic organisms from prokaryotes to small mesopelagic fishes collected during the Malaspina 2010 Expedition. β-diversity was compared to surface ocean transit times derived from a global circulation model, revealing a significant negative relationship that is stronger than environmental differences. Estimated dispersal scales for different groups show a negative correlation with body size, where less abundant large-bodied communities have significantly shorter dispersal scales and larger species spatial turnover rates than more abundant small-bodied plankton. Our results confirm that the dispersal scale of planktonic and micro-nektonic organisms is determined by local abundance, which scales with body size, ultimately setting global spatial patterns of diversityThis research was funded by the project Malaspina 2010 Circumnavigation Expedition (Consolider-Ingenio 2010, CSD2008-00077) and cofounded by the Basque Government (Department Deputy of Agriculture, Fishing and Food Policy). [...] E.V. was supported by a PhD Scholarship granted by the Iñaki Goenaga−Technology Centres FoundationPeer Reviewe

    Global beta diversity patterns of microbial communities in the surface and deep ocean

    Get PDF
    This is contribution 1112 from AZTI Marine Research Division.-- 14 pages, 4 figures, 3 tables, supporting information https://doi.org/10.1111/geb.13572.-- Data Availability Statement: DNA sequences for surface prokaryotes are publicly available at the European Nucleotide Archive [http://www.ebi.ac.uk/ena; accession number PRJEB25224 (16S rRNA genes)], for deep prokaryotes at the National Center for Biotechnology Information (NCBI) Sequence Read Archive (http://www.ncbi.nlm.nih.gov/Traces/sra) under accession ID SRP031469, and for surface and deep picoeukaryotes at the European Nucleotide Archive with accession number PRJEB23771 (http://www.ebi.ac.uk/ena). Environmental data used in this study are available from https://github.com/ramalok/malaspina.surface.metabacoding, Giner et al. (2020) and Salazar et al. (2015). The code to analyze the data and produce the figures of this research is available from the corresponding author upon request.-- This is the pre-peer reviewed version of the following article: Ernesto Villarino, James R. Watson, Guillem Chust ,A. John Woodill, Benjamin Klempay, Bror Jonsson, Josep M. Gasol, Ramiro Logares, Ramon Massana, Caterina R. Giner, Guillem Salazar, X. Anton Alvarez-Salgado, Teresa S. Catala, Carlos M. Duarte, Susana Agusti, Francisco Mauro, Xabier Irigoien, Andrew D. Barton; Global beta diversity patterns of microbial communities in the surface and deep ocean; Global Ecology and Biogeography 31(11): 2323-2336 (2022), which has been published in final form at https://doi.org/10.1111/geb.13572. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived VersionsAim: Dispersal and environmental gradients shape marine microbial communities, yet the relative importance of these factors across taxa with distinct sizes and dispersal capacity in different ocean layers is unknown. Here, we report a comparative analysis of surface and deep ocean microbial beta diversity and examine how these patterns are tied to oceanic distance and environmental gradients. Location: Tropical and subtropical oceans (30°N–40°S). Time period: 2010-2011. Major taxa studied: Prokaryotes and picoeukaryotes (eukaryotes between 0.2 and 3 μm). Methods: Beta diversity was calculated from metabarcoding data on prokaryotic and picoeukaryotic microbes collected during the Malaspina expedition across the tropical and subtropical oceans. Mantel correlations were used to determine the relative contribution of environment and oceanic distance driving community beta diversity. Results: Mean community similarity across all sites for prokaryotes was 38.9% in the surface and 51.4% in the deep ocean, compared to mean similarity of 25.8 and 12.1% in the surface and deep ocean, respectively, for picoeukaryotes. Higher dispersal rates and smaller body sizes of prokaryotes relative to picoeukaryotes likely contributed to the significantly higher community similarity for prokaryotes compared with picoeukaryotes. The ecological mechanisms determining the biogeography of microbes varied across depth. In the surface ocean, the environmental differences in space were a more important factor driving microbial distribution compared with the oceanic distance, defined as the shortest path between two sites avoiding land. In the deep ocean, picoeukaryote communities were slightly more structured by the oceanic distance, while prokaryotes were shaped by the combined action of oceanic distance and environmental filtering. Main conclusions: Horizontal gradients in microbial community assembly differed across ocean depths, as did mechanisms shaping them. In the deep ocean, the oceanic distance and environment played significant roles driving microbial spatial distribution, while in the surface the influence of the environment was stronger than oceanic distanceData collection was funded by the Malaspina 2010 Circumnavigation Expedition project (Consolider-Ingenio 2010, CSD2008-00077) and cofunded by the Basque Government (Department Deputy of Agriculture, Fishing and Food Policy). We acknowledge funding from the Spanish Government through the “Severo Ochoa Center of Excelence” accreditation CEX2019-000928-S. [...] We also acknowledge H2020 Mission Atlantic project (Ref. Grant Agreement Number 862428). EV was supported by an international exchange post-doc scholarship to Scripps Institution of Oceanography and Oregon State University granted by the Education Department of the Basque GovernmentPeer reviewe

    Experimental study of differentially rotating supersonic plasma flows produced by aluminium wire array Z-pinches

    No full text
    A novel approach to cylindrical wire array z-pinches has been developed in order to create a rotating plasma flow analogous to astrophysical accretion discs. The method involves subjecting the wire array to a cusp magnetic field (B_r) to create converging off axis ablation streams to form a rotating flow. The rotation is sustained by the ram pressure of the ablation streams in a quasi-equilibrium state for approximately 150 ns. This corresponds to one full rotation of the plasma about the axis. The rotating plasma is supersonic with Mach number ~2 and a radially constant rotation velocity between 60 and 75 km/s; the angular velocity therefore has an r^-1 dependence and the flow is differential. A Thomson scattering diagnostic is used to measure the electron and ion temperatures as Te ~30 eV and Ti >55 eV and the ionisation of the plasma (Z) between 6 and 8. These parameters are used to calculate the Reynolds number (10^5 to 10^6) and magnetic Reynolds numbers (20 to 100) which are large enough for viscous and resistive effects to be negligible on the large scale of the flow. These are of sufficient magnitude for the experiment to be scalable to astrophysical accretion discs. Further more the Reynolds number for the experiment is large enough for shear instabilities to manifest in the plasma. Some evidence for this can be seen in XUV images and Thomson spectra which indicate the development of perturbations and vorticity within the flow. Predictions for the growth rate of the Kelvin Helmholtz instability, 12 to 40 ns, agree reasonably well with the observed perturbation growth of ~30 ns. It is also possible that shear instabilities are driving hydrodynamic turbulence. Turbulent heating of the plasma could explain the approximately 500 eV increase in the ion temperature observed from some Thomson spectra. Further work is required however to prove the existence of shear flows and turbulence within the experiments.Open Acces

    Nord-Sud : una realitat indefugible

    No full text
    Complementa a esta publicación un libro del profesor con el título: Nord-Sud ; Quart món ; Aquí...un amic. Premio Educación y Sociedad 1993Tras una introducción sobre las características socio-económicas de los países considerados como desarrollados frente a los países no desarrollados del sur, se sugieren actividades para trabajar diversos aspectos de dicha problemática.CataluñaBiblioteca de Educación del Ministerio de Educación, Cultura y Deporte; Calle San Agustín 5 -3 Planta; 28014 Madrid; Tel. +34917748000; [email protected]

    Nord-Sud ; Quart Món ; Aquí un amic : llibre de l'educador

    No full text
    Libro del profesor que aborda la problemática de desequilibrio entre los países ricos y los países pobres, desigualdad de oportunidades y Tercer Mundo, desde una perspectiva crítica y de responsabilidad solidaria. Contiene la programación, los aspectos teóricos, las orientaciones y propuestas didácticas, así como una propuesta de evaluación respecto a los temas señalados de los que tratan los cuadernos de la colección Senderi: Nord-Sud, Quart Món, Aquí... un amic.CataluñaBiblioteca de Educación del Ministerio de Educación, Cultura y Deporte; Calle San Agustín 5 -3 Planta; 28014 Madrid; Tel. +34917748000; [email protected]

    Mechanism for Hydride-Assisted Rearrangement from Ethylidene to Ethylene in Iridium Cationic Complexes

    No full text
    6 páginas, 3 figuras, 5 esquemas.The cationic hydride alkylidene complexes [TpMe2Ir(═CH−CH3)(H)(PMe3)]+ and [Cp*Ir(═CH−CH3)(H)(PMe3)]+ (TpMe2 = hydrotris(3,5-dimethyl-1-pyrazolyl)borate; Cp* = pentamethylcyclopentadienyl) are experimentally known to tautomerize to the corresponding hydride alkene species. Our computational study on the mechanism shows that the reaction takes place through formation of the corresponding alkyl intermediates, with participation of species involving α- and β-CH agostic interactions. Computed energy barriers reproduce the available experimental kinetic data and agree with a much faster process in the Cp* system. The highest stabilization of the hydride alkylidene complex (the reactant) in the TpMe2 system appears as the main reason for the higher barrier found. The difference between the two complexes is due to the steric effects of the spectator ligands.We thank the ICIQ Foundation, the Spanish Ministerio de Ciencia e Innovacion (Consolider Ingenio 2010 CSD2006-0003 and CSD2007-000006; projects CTQ2007-62814, CTQ2008-06866-CO2-01/BQU, CTQ2008-06866-CO2-02/BQU, and CTQ2008-03077/BQU, FEDER support), Generalitat de Catalunya (grants 2009SGR0259 and XRQTC), and Junta de Andalucia (project numbers FQM-315 and FQM-67). M.B. thanks the Spanish Ministerio de Ciencia e Innovacion for a “Juan de la Cierva” grant.Peer reviewe
    corecore