4,134 research outputs found

    Inmunización y militarización del cuerpo social en Colombia: el Estado en emergencia permanente

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    In this paper I analyze how the strategies of counterinsurgency warfare undertaken in Colombia during the sixties and seventies recreate an immunity politics device. I argue that this device is based on a notion where the nation is understood as a social body threatened and infected by communist ideologies and where the idea of safety and protection involving the administration of violence. I argue that this immunity politics device operates under a self-destructive logic and a notion of delocalized threat that encouraged the militarization of society, the management of fear and the maintenance of State in a permanent emergency. These facts, in turn, enabled to the appeal to the constitutional exceptionalism as a form of standardized government.En este artículo analizo cómo las estrategias de guerra contrainsurgente emprendidas en Colombia durante las décadas de los sesenta y los setenta recrean un dispositivo inmunitario en donde la nación es entendida como un cuerpo social amenazado e infectado por ideologías comunistas y en donde su seguridad y protección contra los actos violentos, suponen la administración de la violencia. Sostengo que este dispositivo inmunitario, opera bajo una lógica autodestructiva y una noción de amenaza deslocalizada que incentivó la militarización de la sociedad, la gestión del miedo y el sostenimiento de un Estado en emergencia permanente. Hechos que, a su vez, permitieron la apelación a la excepcionalidad constitucional como forma de gobierno normalizada

    Fronteras de seguridad en redes privadas virtuales (VPN)

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    El presente trabajo de grado consiste en la elaboración de un documento basado en la investigación sobre la temática de redes privadas virtuales, terminología usada, nociones de enlaces de red, tipos de VPN y arquitecturas de VPNs, hasta el análisis de seguridades de estas redes, con los clientes más usados y la importancia que debe tener en una organización. Inicialmente se presenta una introducción al mundo de las redes de comunicación, contextualizando al lector sobre las generalidades más importantes del tema, una descripción en detalle de una alternativa segura como lo son las VPN, que le permiten a las personas y organizaciones hacer uso de un medio peligroso de comunicación como lo es internet para conectarse con el mundo exterior de una forma fiable. Posteriormente, se hace una descripción de los protocolos de seguridad en las redes privadas virtuales, amenazas en la red y formas de mitigación, para finalizar con una metodología que le permita a las organizaciones escoger una red privada virtual según unos criterios expuestos

    Decision Tree Methods for Predicting Surface Roughness in Fused Deposition Modeling Parts

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    3D printing using fused deposition modeling (FDM) includes a multitude of control parameters. It is difficult to predict a priori what surface finish will be achieved when certain values are set for these parameters. The objective of this work is to compare the models generated by decision tree algorithms (C4.5, random forest, and random tree) and to analyze which makes the best prediction of the surface roughness in polyethylene terephthalate glycol (PETG) parts printed in 3D using the FDM technique. The models have been created using a dataset of 27 instances with the following attributes: layer height, extrusion temperature, print speed, print acceleration, and flow rate. In addition, a dataset has been created to evaluate the models, consisting of 15 additional instances. The models generated by the random tree algorithm achieve the best results for predicting the surface roughness in FDM parts

    Improvement of Surface Roughness and Hydrophobicity in PETG Parts Manufactured via Fused Deposition Modeling (FDM): An Application in 3D Printed Self–Cleaning Parts

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    The fused deposition modeling (FDM) technique is used today by companies engaged in the fabrication of tra c signs for the manufacture of light-emitting diode LED spotlights. In this sector, the surface properties of the elements used (surface finish, hydrophobic features) are decisive because surfaces that retain little dirt and favor self–cleaning behavior are needed. A design of experiments (L27) with five factors and three levels has been carried out. The factors studied were: Layer height (LH), print temperature (T), print speed (PS), print acceleration (PA), and flow rate (F). Polyethylene terephthalate glycol (PETG) specimens of 25.0 25.0 2.4 mm have been printed and, in each of them, the surface roughness (Ra,0, Ra,90), sliding angle (SA0, SA90), and contact angle (CA0, CA90) in both perpendicular directions have been measured. Taguchi and ANOVA analysis shows that the most influential variables in this case are printing acceleration for Ra, 0 (p–value = 0.052) and for SA0 (p–value = 0.051) and flow rate for Ra, 90 (p–value = 0.001) and for SA90 (p–value = 0.012). Although the ANOVA results for the contact angle are not significant, specimen 8 (PA = 1500 mm/s2 and flow rate F = 110%) and specimen 10 (PA =1500 mm/s2 and F = 100%) have reached contact angle values above or near the limit value for hydrophobia, respectively

    Ischemia detection from morphological QRS angles changes

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    In this paper, an ischemia detector is presented based on the analysis of QRS-derived angles. The detector has been developed by modeling ischemic effects on the QRS angles as a gradual change with a certain transition time and assuming a Laplacian additive modeling error contaminating the angle series. Both standard and non-standard leads were used for analysis. Non- standard leads were obtained by applying the PCA technique over specific lead subsets to represent different potential locations of the ischemic zone. The performance of the proposed detector was tested over a population of 79 patients undergoing percutaneous coronary intervention in one of the major coronary arteries (LAD (n = 25), RCA (n = 16) and LCX (n = 38)). The best detection performance, obtained for standard ECG leads, was achieved in the LAD group with values of sensitivity and specificity of Se = 90.9%, Sp = 95.4%, followed by the RCA group with Se = 88.9%, Sp = 94.4 and the LCX group with Se = 86.1%, Sp = 94.4%, notably outperforming detection based on the ST series in all cases, with the same detector structure. The timing of the detected ischemic events ranged from 30 s up to 150 s (mean = 66.8 s) following the start of occlusion. We conclude that changes in the QRS angles can be used to detect acute myocardial ischemi

    Galaxy populations in the Antlia cluster - III. Properties of faint early-type galaxies

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    (Abridge) We present a new analysis of the early-type galaxy population in the central region of the Antlia cluster, focusing on the faint systems like dwarf ellipticals (dE) and dwarf spheroidals (dSph). We confirm 22 early-type galaxies as Antlia members, using GEMINI-GMOS and MAGELLAN-MIKE spectra. Among them, 2 belong to the rare type of compact ellipticals (cE), and 5 are new faint dwarfs that had never been catalogued before. In addition, we present 16 newly identified low surface brightness galaxy candidates, almost half of them displaying morphologies consistent with being Antlia's counterparts of Local Group dSphs, that extend the faint luminosity limit of our study down to MB = -10.1 (BT = 22.6) mag. We built an improved CMR in the Washington photometric system, i.e. integrated T1 magnitudes versus (C - T1) colours, which extends \sim 4 mag faintwards the limit of spectroscopically confirmed Antlia members. When only confirmed early-type members are considered, this relation extends over 10 mag in luminosity with no apparent change in slope or increase in colour dispersion towards its faint end. The intrinsic colour scatter of the relation is compared with those reported for other clusters of galaxies; we argue that it is likely that the large scatter of the CMR, usually reported at faint magnitudes, is mostly due to photometric errors along with an improper membership/morphological classification. The distinct behaviour of the luminosity versus mean effective surface brightness relation at the bright and faint ends is analyzed, while it is confirmed that dE galaxies on the same relation present a very similar effective radius, regardless of their colour. The projected spatial distribution of the member sample confirms the existence of two groups in Antlia, each one dominated by a giant elliptical galaxy and with one cE located close to each giant.Comment: 19 pages, 9 figures, 5 tables. Accepted for publication in MNRA

    Temporal and spatial expression of genes involved in DNA methylation during reproductive development of sexual and apomictic Eragrostis curvula

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    Recent reports in model plant species have highlighted a role for DNA methylation pathways in the regulation of the somatic-to-reproductive transition in the ovule, suggesting that apomixis (asexual reproduction through seeds) likely relies on RdDM downregulation. Our aim was therefore to explore this hypothesis by characterizing genes involved in DNA methylation in the apomictic grass Eragrostis curvula. We explored floral transcriptomes to identify homologs of three candidate genes, for which mutations in Arabidopsis and maize mimic apomixis (AtAGO9/ZmAGO104, AtCMT3/ZmDMT102/ZmDMT105, and AtDDM1/ZmCHR106), and compared both their spatial and temporal expression patterns during reproduction in sexual and apomictic genotypes. Quantitative expression analyses revealed contrasting expression patterns for the three genes in apomictic vs sexual plants. In situ hybridization corroborated these results for two candidates, EcAGO104 and EcDMT102, and revealed an unexpected ectopic pattern for the AGO gene during germ line differentiation in apomicts. Although our data partially support previous results obtained in sexual plant models, they suggest that rather than an RdDM breakdown in the ovule, altered localization of AtAGO9/ZmAGO104 expression is required for achieving diplospory in E. curvula. The differences in the RdDM machinery acquired during plant evolution might have promoted the emergence of the numerous apomictic paths observed in plants.Fil: Selva, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; ArgentinaFil: Siena, Lorena Adelina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Investigaciones en Ciencias Agrarias de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Instituto de Investigaciones en Ciencias Agrarias de Rosario; ArgentinaFil: Rodrigo, Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentina. Universidad Nacional del Sur. Departamento de Agronomía; ArgentinaFil: Garbus, Ingrid. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentina. Universidad Nacional del Sur. Departamento de Ciencias de la Salud; ArgentinaFil: Zappacosta, Diego Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentina. Universidad Nacional del Sur. Departamento de Agronomía; ArgentinaFil: Romero, José Rodolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; ArgentinaFil: Ortiz, Juan Pablo Amelio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Investigaciones en Ciencias Agrarias de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Instituto de Investigaciones en Ciencias Agrarias de Rosario; ArgentinaFil: Pessino, Silvina Claudia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Investigaciones en Ciencias Agrarias de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Instituto de Investigaciones en Ciencias Agrarias de Rosario; ArgentinaFil: Leblanc, O.. Universidad de Montpellier; AlemaniaFil: Echenique, Carmen Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentina. Universidad Nacional del Sur. Departamento de Agronomía; Argentin

    Cambio climático: impactos y perspectivas de investigación desde una visión multidisciplinar

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    La preocupación que en los últimos años ha surgido por parte de los países desarrollados ante los crecientes impactos económicos generados por el Cambio Climático el cual se refleja en el incremento del número de investigaciones en este campo. La mayoría de los estudios muestran que el Cambio Climático afecta múltiples aspectos del entorno trayendo como resultado impactos directos sobre la economía de un país que en la mayoría de los casos se evidencia en alteraciones positivas y negativas del PIB. Los mayores impactos se presentan en los países del trópico donde paradójicamente hay una cantidad relativamente baja de investigaciones que aborden a profundidad el tema, siendo una posible causa de esto el desconocimiento que se tiene de los conceptos fundamentales relacionados con el tema. Este trabajo muestra desde una revisión actualizada y exhaustiva de la literatura un marco conceptual general que sirve como base para emprender procesos de investigación desde una perspectiva multidisciplinar alrededor de los principales impactos del Cambio Climático
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