213 research outputs found

    El pensamiento político de Hostos

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    Libros

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    Modeling Gamma-ray burst Afterglow observations with an Off-axis Jet emission

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    Gamma-ray bursts (GRBs) are fascinating extragalactic objects. They represent a fantastic opportunity to investigate unique properties not exhibited in other sources. Multi-wavelength afterglow observations from some short- and long-duration GRBs reveal an atypical long-lasting emission that evolves differently from the canonical afterglow light curves favoring the off-axis emission. We present an analytical synchrotron afterglow scenario, and the hydrodynamical evolution of an off-axis top-hat jet decelerated in a stratified surrounding environment. The analytical synchrotron afterglow model is shown during the coasting, deceleration (off- and on-axis emission), and the post-jet-break decay phases, and the hydrodynamical evolution is computed by numerical simulations showing the time evolution of the Doppler factor, the half-opening angle, the bulk Lorentz factor, and the deceleration radius. We show that numerical simulations are in good agreement with those derived with our analytical approach. We apply the current synchrotron model and describe successfully the delayed non-thermal emission observed in a sample of long and short GRBs with evidence of off-axis emission. Furthermore, we provide constraints on the possible afterglow emission by requiring the multi-wavelength upper limits derived for the closest Swift-detected GRBs and promising gravitational-wave events.Comment: 36 pages, 16 figures, accepted for publication in Ap

    Climate change and ecosystem services: a participatory approach in a Brazilian mountainous region.

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    Climate change is present in all sectors of global societies, causing various damages, including to agriculture. In this process, understanding the perception of the most affected population and including them in decision-making is a matter of social justice and a more assertive path. Aiming to obtain subsidies for better adaptation to climate change in family farming, this study established a methodology for evaluating the risks of climate change impacts on ecosystem services, related to water and food security, under the perception of rural actors in the mountainous region of the Rio de Janeiro state, Brazil. The methodology consisted of five steps, including the application of the questionnaire to 29 rural actors and ending with validation of the results in a focus group. The main results obtained were that the interviewees perceive the risks of the impacts of climate change in ES, both related to water and food security. Additionally, 24.14% of interviewees mentioned that their family has a monthly income below the Brazilian minimum wage, which exposes their food insecurity. In relation to water security, the risks classified as Very High were mainly in relation to low per capita investments in adaptation policies and infrastructure for environmental protection, between others. The use of many chemical inputs in agriculture also highlighted as a risk to water and food security. Regarding the methodology, it concluded that it was effective in obtaining the perception of the rural actors interviewed regarding the impacts of climate change on ecosystem services at a local scale

    Orogenias paleozoicas en los Andes de Argentina y Chile y en la Península Antártica

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    Congreso Geológico Argentino (20º. 2017. San Miguel de Tucumán, Argentina). Simposio de Téctonica pre-andinaDurante el Neoproterozoico y Paleozoico, los Andes de Argentina y Chile, y desde fines del Paleozoico también la Península Antártica, formaron parte del margen SO de Gondwana. Durante este tiempo se acrecionaron a dicho margen varios fragmentos continentales de tamaño y aloctonía variable; denominados de N a S: Antofalla, Chi-Cu, Patagonia Occidental y Antártida Occidental. Estos fragmentos formaban parte de placas litosféricas, en ocasiones divididas en subplacas. La colisión de dichos fragmentos continentales con Gondwana y una última subducción bajo dicho margen, dieron lugar a 6 orogenias de extensión temporal y espacial limitada.Instituto Geológico y Minero de España, EspañaDepartamento de Geología, Universidad de Oviedo, EspañaUniversidad de Río Negro, ArgentinaServicio Geológico y Minero Argentino, ArgentinaInstituto De Bio y Geociencias Del NOA, Consejo Nacional de Investigaciones Científicas y Técnicas, ArgentinaInstituto De Bio y Geociencias Del NOA, Universidad Nacional de Salta, ArgentinaDepartamento de Geodinámica, Universidad del País Vasco, EspañaFacultad de Geología, Universidad de Barcelona, EspañaDepartamento de Geología, Universidad de Chile, ChileUniversidad Andrés Bello, ChileUnidad de Tectónica, Consejo Nacional de Investigaciones Científicas y Técnicas, ArgentinaFacultad de Geología, Universidad de Buenos Aires, ArgentinaÁrea de Geología, Universidad Rey Juan Carlos, EspañaUniversidad de Salta, ArgentinaInstituto de Investigación en Paleobiología y Geología, Universidad de Río Negro, ArgentinaInstituto de Investigación en Paleobiología y Geología, Consejo Nacional de Investigaciones Científicas y Técnicas, ArgentinaCentro de Investigaciones Geológicas, Universidad de La Plata, ArgentinaUniversidad de San Juan, ArgentinaPeer reviewe

    Automated database-guided expert-supervised orientation for immunophenotypic diagnosis and classification of acute leukemia

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    Precise classification of acute leukemia (AL) is crucial for adequate treatment. EuroFlow has previously designed an AL orientation tube (ALOT) to guide towards the relevant classification panel (T-cell acute lymphoblastic leukemia (T-ALL), B-cell precursor (BCP)-ALL and/or acute myeloid leukemia (AML)) and final diagnosis. Now we built a reference database with 656 typical AL samples (145 T-ALL, 377 BCP-ALL, 134 AML), processed and analyzed via standardized protocols. Using principal component analysis (PCA)-based plots and automated classification algorithms for direct comparison of single-cells from individual patients against the database, another 783 cases were subsequently evaluated. Depending on the database-guided results, patients were categorized as: (i) typical T, B or Myeloid without or; (ii) with a transitional component to another lineage; (iii) atypical; or (iv) mixed-lineage. Using this automated algorithm, in 781/783 cases (99.7%) the right panel was selected, and data comparable to the final WHO-diagnosis was already provided in >93% of cases (85% T-ALL, 97% BCP-ALL, 95% AML and 87% mixed-phenotype AL patients), even without data on the full-characterization panels. Our results show that database-guided analysis facilitates standardized interpretation of ALOT results and allows accurate selection of the relevant classification panels, hence providing a solid basis for designing future WHO AL classifications

    MARIBNO project: Structure of the NorthWest Iberian margin: influence of inherited tectonics in the Alpine extension and inversion

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    X Congreso Geológico de España, 5-7 Julio 2021, Vitoria - GasteizLa zona noroeste de Iberia reúne rasgos geológicos excepcionales relacionados con el desarrollo de un margen continental hiperextendido cerca de un punto triple y la posterior inversión tectónica parcial. Es una zona de gran interés para el estudio del papel de la herencia tectónica y la posterior inversión en márgenes continentales extensionales, pero hay un gran déficit de información. Todo esto sienta las bases del proyecto anfibio MARIBNO (PGC2018-095999-B-I00) donde a lo largo de 2021 y 2022 se adquirirán sísmica marina de reflexión multicanal 2D (~4000 km), sísmica de gran ángulo en 3 transectos tierra-mar (~600 km), batimetría multihaz, grav-mag y sísmica de alta resolución. Se complementará en tierra con adquisición de datos grav-mag y varias campañas de cartografía geológica. Los objetivos se centran en el estudio de la estructura cortical, el control tectónico ejercido por estructuras previas a las etapas alpinas y la cartografía y caracterización de los dominios corticales aunando criterios geológicos y geofísicos.Todo esto sienta las bases del proyecto anfibio MARIBNO (PGC2018-095999-B-I00) donde a lo largo de 2021 y 2022 se adquirirán sísmica marina de reflexión multicanal 2D (~4000 km), sísmica de gran ángulo en 3 transectos tierra-mar (~600 km), batimetría multihaz, grav-mag y sísmica de alta resolución

    First results from the AugerPrime Radio Detector

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