64 research outputs found

    Metodología para Optimización Topológica y de Forma de Elementos Estructurales

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    The Hybrid Cellular Automaton (HCA) algorithm is a methodology developed to simulate the process of functional adaptation in bones. The HCA algorithm combines elements of the cellular automaton (CA) paradigm with finite element analysis. This methodology has proved to be computationally efficient to solve topology optimization problems. In this paper, the HCA algorithm is integrated with a shape optimization algorithm that uses sequential quadratic programming. The geometry of the topologically optimized structure is converted into a two-dimensional solid model using an edge detection algorithm and parametric B-splines. An example problem of a Michell structure is presented. Also shown is the application of the shape optimization algorithm in the redesign of the lightening holes in the transverse floors of a riverine patrol vessel designed by COTECMAR. In both cases an appreciable weight reduction was obtained.El método de los Autómatas Celulares Híbridos (HCA) para optimización topológica simula el proceso de adaptación funcional en estructuras óseas. El método HCA combina la técnica de los elementos finitos para análisis estructural con el paradigma de los Autómatas celulares (CA) para el diseño y ha demostrado ser una técnica efectiva para optimización topológica en estructuras continuas. En este trabajo se integra el método HCA con un algoritmo de optimización de forma que utiliza programación cuadrática secuencial. La geometría optimizada topológicamente es utilizada para construir un modelo bidimensional sólido aplicando un algoritmo de detección de bordes en imágenes y esplines paramétricos. Un ejemplo de una estructura Michell es presentado. También es presentada la aplicación de un algoritmo de optimización de forma en el diseño de unos aligeramientos en las varengas de un buque patrullero fluvial diseñado por COTECMAR. En ambos casos una apreciable reducción del peso fue obtenida

    Evolution of a fluvial-dominated delta during the Oligocene of the Colombian Caribbean: Sedimentological and ichnological signatures in well-cores

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    We would like to thank Dr. Pazos (JSAES Guest Editor) and two anonymous reviewers by constructive comments and suggestions. Thanks to the National Hydrocarbons Agency-ANH, and Ministerio de Ciencia, Tecnologia e Innovacion-Minciencias to allow the study of well-core (project Contrato RC 494-2017) . The Vicerrectoria de Inves-tigaciones y Posgrados and the Instituto de Investigaciones en Estrati-grafia-IIES of Universidad de Caldas gave economic and logistic support. The research was conducted within the "Ichnology and Palaeoenviron-ment RG" (UGR) . Financial support of Rodriguez-Tovar was provided by scientific Projects CGL 2015-66835-P and CTM 2016-75129-C3-2-R (Secretaria de Estado de I + D + I, Spain) , and B-RNM-072-UGR18 (FEDER Andalucia) , and Research Group RNM-178 (Junta de Andalucia) . Funding for open access charge: Universidad de Granada/CBUA. Thanks to Fabian Gallego for his contribution in some sedimentological discussions.Basin analysis from Colombian Caribbean is particularly important given the interest in finding hydrocarbon reservoirs, but their complex geological evolution, and the frequent lateral and vertical variation of facies difficult a conclusive characterization, highlights the need for detailed sedimentological and ichnological studies. The study succession corresponds to an interval of a well core drilled in the south of the Sinu-San Jacinto Basin (Colombian Caribbean), with 1069 ft (similar to 326 m) thick of an Oligocene siliciclastic succession, interpreted in general terms, as deposited in a deltaic system. The integrated sedimentological/ichnological analysis allows the differentiation of dominant facies, with predominant lithologies such as conglomerates, sandstones, mudrocks, bioclastic sediments, as well as coal beds. The ichnological assemblage is low in abundance and moderately diverse, composed by Conichnus, Cylindrichnus, Dactyloidites, Macaronichnus, Ophiomorpha, Phycosiphon, Skolithos, Taenidium, Teichichnus, and Thalassinoides, as well as rhizoliths. The complexity of the sedimentary system is reflected in its evolution throughout the Oligocene. A type succession with coarsening-upward trend was identified and it is repeated through the succession studied. It presents a general trend from bioclastic sediments (bioclastic conglomerates, sandstones and mudrocks) that pass into horizontal lamination and massive mudrocks occasionally bioturbated by Phycosiphon, and interbedded by mudrocks and sandstones with lenticular bedding, and the occurrence of Teichichnus. Above, bioturbated muddy sandstones with Ophiomorpha, Taenidium, Thalassinoides, and rarely Teichichnus, muddy sandstones with planar cross-lamination, and horizontal lamination sandstones with Dactyloidites, Ophiomorpha, Skolithos, and Thalassinoides are registered. Transition to carbonaceous mudrocks with Teichichnus, coal medium beds, and fine-to coarse-grained sandstones sometimes with Macaronichnus and/or Ophiomorpha is observed. Towards the top, are observed mudrocks with rhizoliths. This succession is interrupted by massive and horizontal lamination sandstones with low bioturbation index generated by the ichnological assemblage and/or by the exclusive occurrence of Ophiomorpha and/or Taenidium. Massive sandstones with erosive bases, asymmetrical ripples, and high content of organic debris are occasionally recorded. This succession reflects a progradational trend similar to those of fluvial-dominated deltaic sequences. Detailed analysis revealed that even the fluvial processes were dominant in the deltaic system; however, local tidal and wave influence is recorded. Moreover, integration of sedimentological and ichnological information allows characterizing the evolution of the different sub-environments of the deltaic system, as prodelta bay, distal delta front, proximal delta front, distributary channels, mouth bars, and lower delta plain, and this is essential for areas of economic interest.Ministerio de Ciencia, Tecnologia e Innovacion-Minciencias RC 494-2017Secretaria de Estado de I + D + I, Spain CGL 2015-66835-P- CTM 2016-75129-C3-2-RFEDER Andalucia B-RNM-072-UGR18Junta de Andalucia RNM-178Universidad de Granada/CBU

    Coarse-grained submarine channels: from confined to unconfined flows in the Colombian Caribbean (late Eocene)

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    Submarine channel mouth settings are hardly preserved in the stratigraphic record. Although they are still poorly known with respect to other segments of turbidite systems, conceptual models are being refined in the light of newdiscoveries inmodern and ancient examples. Still, some questions such as the transition between expansion zones and the traditional Channel-Lobe Transition Zone (CLTZ) remains open in ancient systems. Upper Eocene deposits of the Colombian Caribbean (San Jacinto Fold Belt) are interpreted here as a fan-delta-fed, submarine, coarse-grained channel-lobe system. It displays a well-preserved channel inception stage in the shelf break represented by sigmoidal to lens-shaped gravels, and planar cross-stratified pebbly sandstones (foreset and backset) interpreted as cyclic steps in an expansion zone. In a later stage, a classical channel-levee complex was developed, represented by channel fill elements showing sharp- and erosional-based, fining-upward sequences that aremeters thick, having basal massive matrix-supported pebble conglomerates (hard—extrabasinal—clasts, rip-up clasts, coastal bioclasts), vertically evolving to liquefied massive to planar-laminated coarse-grained sandstones with phytodetrital carbonaceous laminae. They are interpreted as concentrated flow deposits (high-density turbidites) coming from continental areas or from coastal systems (i.e., delta reworking). Undifferentiated channel belt thin-bedded turbidites associated with levees and terraces deposits are related to these confined systems. The channel-lobe transition zone is characterized by debrites from cohesionless debris flow in a channelmouth bar setting, representing bypass processes that developed distally into low-angle, planar cross- and sigmoidally- stratified (upstream antidune) pebble-size to coarse-grained sandstones that fill low-angle scours (cut-and-fill structures) in an antidune field settingwith supercritical conditions.When the currents lose channel confinement, the setting is characterized by changes fromFroude supercritical to subcritical flowconditions in an inner lobe to lobe off-axis environment. Large seasonal fluctuations in precipitation favor high sediment concentrations, promoting the formation of volumetrically significant fan deltas and coarse-grained submarine channels with high erosive capacity; therefore, their record helps refine interpretations of depositional processes, providing criteria for recognizing areas of the turbiditic systems that are hardly preserved. The particular aggradational conditions for the preservation and stratigraphic characterization of the rare exhumed submarine channelmouth systems make it possible to decipher sediment dispersal patterns and thus connect the models proposed here, from supercritical systems to the traditional models of turbiditic systems.National Programfor Doctoral Formation (Minciencias Colombia grants 885-2020, 906-2021)Project PID2019-104625RB-100 (funded by MCIN/AEI/10.13039/501100011033)Project P18-RT-4074 (funded by FEDER/Junta de Andalucía-Consejería de Economía y Conocimiento)Projects B-RNM-072-UGR18 and A-RNM-368-UGR20 (funded by FEDER Andalucía)Funding for open access charge: Universidad de Granada / CBU

    Spread COVID-19 during Godzilla African dust in June 2020 on the Colombian Caribbean region

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    Recent studies show that aerosols are highly linked to the spread of the COVID−19 pandemic. Furthermore, during this pandemic, the largest Saharan dust intrusion event has reached the Caribbean region in the last 20 years, called “Godzilla” African Dust or GAD. This study aims to analyze the correlation between the spread of COVID−19 and the GAD event in the main cities of the Colombian Caribbean region. The results showed a positive correlation between the spread of COVID−19 and the GAD event in most cities. Our findings could serve as input for the development of a strategy in the prevention of COVID−19 and other similar viral diseases during the Saharan dust intrusion events that reach the Caribbean region each year from Africa. Our results may help design strategies to prevent future outbreaks of COVID-19 and reduce the risk of future pandemics of similar viral diseases. Especially during the Saharan dust intrusion events that reach the Caribbean region each year.Fil: Bolaño Ortiz, Tomás R.. Universidad Católica de Maule; ChileFil: Constante Ballestas, Jelaine I.. Universidad del Magdalena; ColombiaFil: Puliafito, Salvador Enrique. Universidad Tecnológica Nacional; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; ArgentinaFil: Vélez Pereira, Andrés Mauricio. Universidad de Tarapacá; ChileFil: Tovar Bernal, Fredy A.. Universidad del Magdalena; ColombiaFil: Camargo Caicedo, Yiniva. Universidad del Magdalena; Colombi

    All about (nk cell-mediated) death in two acts and an unexpected encore: initiation, execution and activation of adaptive immunity

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    NK cells are key mediators of immune cell-mediated cytotoxicity toward infected and transformed cells, being one of the main executors of cell death in the immune system. NK cells recognize target cells through an array of inhibitory and activating receptors for endogenous or exogenous pathogen-derived ligands, which together with adhesion molecules form a structure known as immunological synapse that regulates NK cell effector functions. The main and best characterized mechanisms involved in NK cell-mediated cytotoxicity are the granule exocytosis pathway (perforin/granzymes) and the expression of death ligands. These pathways are recognized as activators of different cell death programmes on the target cells leading to their destruction. However, most studies analyzing these pathways have used pure recombinant or native proteins instead of intact NK cells and, thus, extrapolation of the results to NK cell-mediated cell death might be difficult. Specially, since the activation of granule exocytosis and/or death ligands during NK cell-mediated elimination of target cells might be influenced by the stimulus received from target cells and other microenvironment components, which might affect the cell death pathways activated on target cells. Here we will review and discuss the available experimental evidence on how NK cells kill target cells, with a special focus on the different cell death modalities that have been found to be activated during NK cell-mediated cytotoxicity; including apoptosis and more inflammatory pathways like necroptosis and pyroptosis. In light of this new evidence, we will develop the new concept of cell death induced by NK cells as a new regulatory mechanism linking innate immune response with the activation of tumour adaptive T cell responses, which might be the initiating stimulus that trigger the cancer-immunity cycle. The use of the different cell death pathways and the modulation of the tumour cell molecular machinery regulating them might affect not only tumour cell elimination by NK cells but, in addition, the generation of T cell responses against the tumour that would contribute to efficient tumour elimination and generate cancer immune memory preventing potential recurrences

    Derecho a la comunicación en América Latina

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    Este libro es el resultado del Segundo encuentro presencial de la Red de Derecho a la Comunicación y la Democracia vinculado a la Asociación de Universidades Confiadas a la Compañía de Jesús en América Latina (AUSJAL), evento realizado por el Departamento de Comunicación de la Universidad Católica de Uruguay el 24 y 25 de septiembre de 2018, en Montevideo. La consolidación de este proyecto editorial se fundamentó en la necesidad de generar una experiencia académica para el mutuo conocimiento de las trayectorias en investigación y la aproximación particular a los casos relativos al derecho a la comunicación en América Latina por parte de los homólogos AUSJAL. De esta forma, en la escritura de este manuscrito participaron profesores y profesoras de la Universidad Iberoamericana (México), la Universidad Iberoamericana Puebla (México), la Universidad Iberoamericana Torreón (México), el Instituto Tecnológico y de Estudios Superiores de Occidente-ITESO (México), la Universidad Rafael Landívar (Guatemala), la Universidad Centroamericana José Simeón Cañas (El Salvador), la Pontificia Universidad Católica del Ecuador, la Universidad Alberto Hurtado (Chile), la Universidad Católica del Uruguay, y la Pontificia Universidad Javeriana Cali (Colombia)

    The cyanobacterial saxitoxin exacerbates neural cell death and brain malformations induced by zika virus

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    The northeast (NE) region of Brazil commonly goes through drought periods, which favor cyanobacterial blooms, capable of producing neurotoxins with implications for human and animal health. The most severe dry spell in the history of Brazil occurred between 2012 and 2016. Coincidently, the highest incidence of microcephaly associated with the Zika virus (ZIKV) outbreak took place in the NE region of Brazil during the same years. In this work, we tested the hypothesis that saxitoxin (STX), a neurotoxin produced in South America by the freshwater cyanobacteria Raphidiopsis raciborskii, could have contributed to the most severe Congenital Zika Syndrome (CZS) profile described worldwide. Quality surveillance showed higher cyanobacteria amounts and STX occurrence in human drinking water sup-plies of NE compared to other regions of Brazil. Experimentally, we described that STX dou-bled the quantity of ZIKV-induced neural cell death in progenitor areas of human brain organoids, while the chronic ingestion of water contaminated with STX before and during gestation caused brain abnormalities in offspring of ZIKV-infected immunocompetent C57BL/6J mice. Our data indicate that saxitoxin-producing cyanobacteria is overspread in water reservoirs of the NE and might have acted as a co-insult to ZIKV infection in Brazil. These results raise a public health concern regarding the consequences of arbovirus outbreaks happening in areas with droughts and/or frequent freshwater cyanobacterial blooms.Fil: Pedrosa, Carolina da S. G.. D’Or Institute for Research and Education; BrasilFil: Souza, Leticia R. Q.. D’Or Institute for Research and Education; BrasilFil: Gomes, Tiago A.. Universidade Federal do Rio de Janeiro; Brasil. Instituto Oswaldo Cruz; BrasilFil: de Lima, Caroline V. F.. D’Or Institute for Research and Education; BrasilFil: Ledur, Pitia F.. D’Or Institute for Research and Education; BrasilFil: Karmirian, Karina. D’Or Institute for Research and Education; Brasil. Universidade Federal do Rio de Janeiro; BrasilFil: Barbeito Andrés, Jimena. Universidade Federal do Rio de Janeiro; Brasil. Universidad Nacional Arturo Jauretche. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos. Provincia de Buenos Aires. Ministerio de Salud. Hospital Alta Complejidad en Red El Cruce Dr. Néstor Carlos Kirchner Samic. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos; ArgentinaFil: Costa, Marcelo do N.. Universidade Federal do Rio de Janeiro; BrasilFil: Higa, Luiza M.. Universidade Federal do Rio de Janeiro; BrasilFil: Rossi, Átila D.. Universidade Federal do Rio de Janeiro; BrasilFil: Bellio, Maria. Universidade Federal do Rio de Janeiro; BrasilFil: Tanuri, Amilcar. Universidade Federal do Rio de Janeiro; BrasilFil: Prata Barbosa, Arnaldo. D’Or Institute for Research and Education; BrasilFil: Tovar Moll, Fernanda. D’Or Institute for Research and Education; Brasil. Universidade Federal do Rio de Janeiro; BrasilFil: Garcez, Patricia P.. Universidade Federal do Rio de Janeiro; BrasilFil: Lara, Flavio A.. Instituto Oswaldo Cruz; BrasilFil: Molica, Renato J. R.. Universidad Federal Rural Pernambuco; BrasilFil: Rehen, Stevens K.. D’Or Institute for Research and Education; Brasil. Universidade Federal do Rio de Janeiro; Brasi

    Regional development gaps in Argentina: A multidimensional approach to identify the location of policy priorities

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    Spatial inequalities within Latin American countries have historically attracted the interest ofacademics, policy-makers, and international agencies. This article aims to provide amultidimensional diagnosis of provincial development gaps in Argentina, in order to identifythe location of policy priorities. Therefore, we built a large database, which covers sevendevelopment dimensions, and applied multivariate analysis techniques to overcome someanalytical limitations of previous studies. Results show the stability of provincial developmentgaps between 2003 and 2013 and some heterogeneity within geographic regions. Instead,cluster analysis offers a better classification of Argentine provinces according to theirdevelopment gaps, which can help the government to prioritize the places wheredevelopment policies are strategic.Fil: Niembro, Andrés Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Universidad Nacional de Río Negro; ArgentinaFil: Sarmiento, Jesica Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Universidad Nacional de Río Negro; Argentin
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