55 research outputs found

    Discourse of work among former combatants of the FARC. Socio-labor barriers to reintegration

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    Discourse analysis is used to identify the meanings and socio-labor barriers perceived by former FARC combatants in the post-conflict scenario, which must be understood to establish frameworks for action in the peace-building process. The interpretative repertoire "to be crossed out" is shown as an ontological mark in the former combatant that deprives him of access to different social settings and that hinders the identity configuration, fostering feelings of nullification of his civil utility.A partir del análisis del discurso se identifican los significados y barreras sociolaborales percibidas por excombatientes de las FARC frente al escenario de postconflicto, que deben ser comprendidas para establecer marcos de actuación en el proceso de construcción de paz. El repertorio interpretativo estar-tachado se muestra como marca ontológica en el excombatiente que le priva para acceder a distintos escenarios sociales y que entorpece la configuración identitaria, fomentando sentimientos de anulación de su utilidad civil

    Coherent coupling between vortex bound states and magnetic impurities in 2D layered superconductors

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    Bound states in superconductors are expected to exhibit a spatially resolved electron-hole asymmetry which is the hallmark of their quantum nature. This asymmetry manifests as oscillations at the Fermi wavelength, which is usually tiny and thus washed out by thermal broadening or by scattering at defects. Here we demonstrate theoretically and confirm experimentally that, when coupled to magnetic impurities, bound states in a vortex core exhibit an emergent axial electron-hole asymmetry on a much longer scale, set by the coherence length. We study vortices in 2H-NbSe2 and in 2H-NbSe1.8S0.2 with magnetic impurities, characterizing these with detailed Hubbard-corrected density functional calculations. We find that the induced electron-hole imbalance depends on the band character of the superconducting material. Our results show that coupling between quantum bound states in superconductors is remarkably robust and has a strong influence in tunneling measurements

    Coral Reef Resilience Index for Novel Ecosystems: A Spatial Planning Tool for Managers and Decision Makers - A Case Study from Puerto Rico

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    Timely information is critical for coral reef managers and decision-makers to implement sustainable management measures. A Coral Reef Resilience Index (CRRI) was developed with a GIS-coupled decision-making tool applicable for Caribbean coral reef ecosystems. The CRRI is based on a five-point scale parameterized from the quantitative characterization of benthic assemblages. Separate subindices such as the Coral Index, the Threatened Species Index, and the Algal Index also provide specific information regarding targeted benthic components. This case study was based on assessments conducted in 2014 on 11 reef sites located across 3 geographic zones and 3 depth zones along the southwestern shelf of the island of Puerto Rico, Caribbean Sea. There was a significant spatial and bathymetric gradient (p < 0.05) in the distribution of CRRI values indicating higher degradation of inshore reefs. Mean global CRRI ranged from 2.78 to 3.17 across the shelf, ranking them as “fair.” The Coral Index ranged from 2.60 to 3.76, ranking reefs from “poor” to “good,” showing a general cross-shelf trend of improving conditions with increasing distance from pollution sources. Turbidity and ammonia were significantly correlated to CRRI scores. Multiple recommendations are provided based on coral reef conditions according to observed CRRI rankings

    Superconducting density of states and band structure at the surface of the candidate topological superconductor Au2 Pb

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    The electronic band structure of Au2Pb has a Dirac cone which gaps when undergoing a structural transition into a low temperature superconducting phase. This suggests that the superconducting phase (Tc = 1.1 K) might hold topological properties at the surface. Here we make Scanning Tunneling Microscopy experiments on the surface of superconducting Au2Pb. We measure the superconducting gap and find a sizable superconducting density of states at the Fermi level. We discuss possible origins for this finding in terms of superconductivity induced into surface state

    Band structure, superconductivity and polytypism in AuSn4_4

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    The orthorhombic compound AuSn4 is compositionally similar to the Dirac node arc semimetal PtSn4_4. AuSn4_4 is, contrary to PtSn4_4, superconducting with a critical temperature of Tc_c = 2.35 K. Recent measurements present indications for quasi two-dimensional superconducting behavior in AuSn4_4. Here we present measurements of the superconducting density of states and the band structure of AuSn4_4 through Scanning Tunneling Microscopy (STM) and Angular Resolved Photoemission Spectroscopy (ARPES). The superconducting gap values in different portions of the Fermi surface are spread around {\Delta}0 = 0.4 meV, which is close to but somewhat larger than Δ=\Delta = 1.76kBTc_c expected from BCS theory. We observe superconducting features in the tunneling conductance at the surface up to temperatures about 20% larger than bulk Tc. The band structure calculated with Density Functional Theory (DFT) follows well the results of ARPES. The crystal structure presents two possible stackings of Sn layers, giving two nearly degenerate polytypes. This makes AuSn4_4 a rather unique case with a three dimensional electronic band structure but properties ressembling those of low dimensional layered compounds

    Observation of a gel of quantum vortices in a superconductor at very low magnetic fields

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    A gel consists of a network of particles or molecules formed for example using the sol-gel process, by which a solution transforms into a porous solid. Particles or molecules in a gel are mainly organized on a scaffold that makes up a porous system. Quantized vortices in type-II superconductors mostly form spatially homogeneous ordered or amorphous solids. Here we present high-resolution imaging of the vortex lattice displaying dense vortex clusters separated by sparse or entirely vortex-free regions in β-Bi2Pd superconductor. We find that the intervortex distance diverges upon decreasing the magnetic field and that vortex lattice images follow a multifractal behavior. These properties, characteristic of gels, establish the presence of a novel vortex distribution, distinctly different from the well-studied disordered and glassy phases observed in high-temperature and conventional superconductors. The observed behavior is caused by a scaffold of one-dimensional structural defects with enhanced stress close to the defects. The vortex gel might often occur in type-II superconductors at low magnetic fields. Such vortex distributions should allow to considerably simplify control over vortex positions and manipulation of quantum vortex states.Fil: Llorens, José Benito. Universidad Autónoma de Madrid; EspañaFil: Embon, Lior. Weizmann Institute Of Science.; IsraelFil: Correa, Alexandre. Consejo Superior de Investigaciones Científicas; España. Instituto de Ciencia de Materiales de Madrid; EspañaFil: González, Jesús David. Universidad del Magdalena; Colombia. Universiteit Antwerp; BélgicaFil: Herrera, Edwin. Universidad Autónoma de Madrid; España. Universidad Central; ColombiaFil: Guillamón, Isabel. Universidad Autónoma de Madrid; EspañaFil: Luccas, Roberto F.. Consejo Superior de Investigaciones Científicas; EspañaFil: Azpeitia, Jon. Consejo Superior de Investigaciones Científicas; EspañaFil: Mompeán, Federico J.. Consejo Superior de Investigaciones Científicas; EspañaFil: García Hernández, Mar. Consejo Superior de Investigaciones Científicas; EspañaFil: Munuera, Carmen. Consejo Superior de Investigaciones Científicas; EspañaFil: Aragón Sánchez, Jazmín. Comisión Nacional de Energía Atómica. Gerencia del Area de Investigación y Aplicaciones No Nucleares. Gerencia de Física (Centro Atómico Bariloche). División Bajas Temperaturas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología - Nodo Bariloche | Comisión Nacional de Energía Atómica. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología - Nodo Bariloche; ArgentinaFil: Fasano, Yanina. Comisión Nacional de Energía Atómica. Gerencia del Area de Investigación y Aplicaciones No Nucleares. Gerencia de Física (Centro Atómico Bariloche). División Bajas Temperaturas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología - Nodo Bariloche | Comisión Nacional de Energía Atómica. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología - Nodo Bariloche; ArgentinaFil: Milosevic, Milorad V.. Universiteit Antwerp; BélgicaFil: Suderow, Hermann. Universidad Autónoma de Madrid; EspañaFil: Anahory, Yonathan. The Hebrew University of Jerusalem; Israe

    Superconducting density of states and band structure at the surface of the candidate topological superconductor Au2Pb

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    [EN] The electronic band structure of Au2Pb has a Dirac cone which gaps when undergoing a structural transition into a low temperature superconducting phase. This suggests that the superconducting phase (Tc = 1.1 K) might hold topological properties at the surface. Here we make Scanning Tunneling Microscopy experiments on the surface of superconducting Au2Pb. We measure the superconducting gap and find a sizable superconducting density of states at the Fermi level. We discuss possible origins for this finding in terms of superconductivity induced into surface states.This work was supported by the Spanish Research State Agency (Grants No. PID2020-114071RB-I00, No. FIS2017-84330-R, No. CEX2018-000805-M, No. RYC-2014-15093, and No. MAT2017-87134-C2-2-R), by the Comunidad de Madrid through program NANOFRONTMAG-CM (Grant No. S2013/MIT-2850), by the European Research Council PNICTEYES Grant Agreement No. 679080 and by the Swedish Research Council (Vetenskapsrådet Grant No. 2018-03488). F.M. and M.G.H. acknowledge European Union’s Horizon 2020 research and innovation program Grant Agreement No. 881603 Graphene Core3-Graphene-based disruptive technologies, EU FLAG-ERA through the project To2Dox, JTC-2019-009 and the Comunidad de Madrid through the project CAIRO-CM project, Y2020/NMT-6661.We acknowledge collaborations through EU program Cost CA16218 (Nanocohybri). J.J.B. acknowledges the Marie Curie Fellowship program (H2020 MSCA-IF2016-751047) and the Generalitat Valenciana (CDEIGENT/2019/022). Ames Laboratory is operated for the U.S. Department of Energy by Iowa State University under Contract No. DE-AC02-07CH11358. We acknowledge SEGAINVEX at UAM for design and construction of cryogenic equipment.Peer reviewe

    Reflexiones universitarias. San Pedro Valencia: renovación urbana, saneamiento ambiental y emprendimientos turísticos. Otoño 2015

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    Los trabajos que aquí se presentan se elaboraron por las y los estudiantes como parte de las actividades del Proyecto de Aplicación Profesional (PAP) “San Pedro Valencia: renovación urbana, saneamiento ambiental y emprendimientos turísticos”, durante el periodo de Otoño de 2015. A lo largo del periodo los autores compartieron sus reflexiones en torno a su percepción sobre el contexto en el que actúa el PAP; sobre las alternativas posibles a la problemática detectada y lo que significa pensar una alternativa; sobre los sujetos con los que se ha interactuado a lo largo de la experiencia de trabajo y sobre el papel del profesionista y del ciudadano en un mundo como el que nos tocó vivir. La obra está compuesta por reflexiones personales de las y los estudiantes que, explorando estas temáticas, comparten sus aprendizajes y observaciones de forma vívida.ITESO, A.C

    Symptom cluster analysis of long COVID-19 in patients discharged from the Temporary COVID-19 Hospital in Mexico City.

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    INTRODUCTION: Several reports have emerged describing the long-term consequences of COVID-19 and its effects on multiple systems. METHODS: As further research is needed, we conducted a longitudinal observational study to report the prevalence and associated risk factors of the long-term health consequences of COVID-19 by symptom clusters in patients discharged from the Temporary COVID-19 Hospital (TCH) in Mexico City. Self-reported clinical symptom data were collected via telephone calls over 90 days post-discharge. Among 4670 patients, we identified 45 symptoms across eight symptom clusters (neurological; mood disorders; systemic; respiratory; musculoskeletal; ear, nose, and throat; dermatological; and gastrointestinal). RESULTS: We observed that the neurological, dermatological, and mood disorder symptom clusters persisted in >30% of patients at 90 days post-discharge. Although most symptoms decreased in frequency between day 30 and 90, alopecia and the dermatological symptom cluster significantly increased (p < 0.00001). Women were more prone than men to develop long-term symptoms, and invasive mechanical ventilation also increased the frequency of symptoms at 30 days post-discharge. CONCLUSION: Overall, we observed that symptoms often persisted regardless of disease severity. We hope these findings will help promote public health strategies that ensure equity in the access to solutions focused on the long-term consequences of COVID-19
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