13,466 research outputs found

    Evidences of evanescent Bloch waves in Phononic Crystals

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    We show both experimentally and theoretically the evanescent behaviour of modes in the Band Gap (BG) of finite Phononic Crystal (PC). Based on experimental and numerical data we obtain the imaginary part of the wave vector in good agreement with the complex band structures obtained by the Extended Plane Wave Expansion (EPWE). The calculated and measured acoustic field of a localized mode out of the point defect inside the PC presents also evanescent behaviour. The correct understanding of evanescent modes is fundamental for designing narrow filters and wave guides based on Phononic Crystals with defects.Comment: 8 pages, 3 figure

    Sites for Gamma-ray Astronomy in Argentina

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    We have searched for possible sites in Argentina for the installation of large air Cherenkov telescope arrays and water Cherenkov systems. At present seven candidates are identified at altitudes from 2500 to 4500 m. The highest sites are located at the Northwest of the country, in La Puna. Sites at 2500 and 3100 m are located in the West at El Leoncito Observatory, with excellent infrastructure. A description of these candidate sites is presented with emphasis on infrastructure and climatology.Comment: Submitted to Proceedings of "4th Heidelberg International Symposium on High Energy Gamma-Ray Astronomy 2008

    Fricke and polymer gel 2D dosimetry validation using Monte Carlo simulation

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    Complexity in modern radiotherapy treatments demands advanced dosimetry systems for quality control. These systems must have several characteristics, such as high spatial resolution, tissue equivalence, three-dimensional resolution, and dose-integrating capabilities. In this scenario, gel dosimetry has proved to be a very promising option for quality assurance. In this study, the feasibility of Fricke and polymer gel dosimeters suitably shaped in form of thin layers and optically analyzed by visible light transmission imaging has been investigated for quality assurance in external radiotherapy. Dosimeter irradiation was carried out with a 6-MV photon beam (CLINAC 600C). The analysis of the irradiated dosimeters was done using two-dimensional optical transmission images. These dosimeters were compared with a treatment plan system using Monte Carlo simulations as a reference by means of a gamma test with parameters of 1 mm and 2%. Results show very good agreement between the different dosimetric systems: in the worst-case scenario, 98% of the analyzed points meet the test quality requirements. Therefore, gel dosimetry may be considered as a potential tool for the validation of other dosimetric systems.Fil: Vedelago, José Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina. Universidad Nacional de Córdoba; ArgentinaFil: Chacón Obando, D.. Universidad Nacional. Physics Department; Costa Rica. Universidad Nacional de Córdoba; ArgentinaFil: Malano, Francisco Mauricio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina. Universidad Nacional de Córdoba; ArgentinaFil: Conejeros, R.. Servicio de Radioterapia, Icos. Temuco, Chile;Fil: Figueroa, R.. Universidad de la Frontera; ChileFil: Garcia, D.. Servicio de Imagenes por Resonancia Magnética; ChileFil: González, G.. Servicio de Imagenes por Resonancia Magnética; ChileFil: Romero, Marcelo Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina. Universidad Nacional de Córdoba; ArgentinaFil: Santibañez, M.. Servicio de Imagenes por Resonancia Magnética; ChileFil: Strumia, Miriam Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Velásquez, J.. Servicio de Radioterapia; ChileFil: Mattea, Facundo. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Valente, M.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina. Universidad de La Frontera. Departamento de Ciencias Físicas; Chil

    Transport and Entanglement Generation in the Bose-Hubbard Model

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    We study entanglement generation via particle transport across a one-dimensional system described by the Bose-Hubbard Hamiltonian. We analyze how the competition between interactions and tunneling affects transport properties and the creation of entanglement in the occupation number basis. Alternatively, we propose to use spatially delocalized quantum bits, where a quantum bit is defined by the presence of a particle either in a site or in the adjacent one. Our results can serve as a guidance for future experiments to characterize entanglement of ultracold gases in one-dimensional optical lattices.Comment: 14 pages, 6 figure

    World knowledge and novel information integration during L2speech comprehension.

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    Published online: 22 January 2016In this study we explore whether world knowledge (WK) processing differs between individuals listening to their native (L1) or their non-native (L2) language. We recorded event-related brain potentials in L1 and L2 speakers of Spanish while they listened to sentences uttered by native speakers of Spanish. Sentences were either congruent or incongruent with participants’ WK. In addition, participants also listened to sentences in which upcoming words could not be anticipated on the basis of WK. WK violations elicited a late negativity of greater magnitude and duration in the L2 than the L1 group. However, sentences in which WK was not helpful regarding word anticipation elicited similar N400 modulations in both groups. These results suggest that WK processing requires a deeper lexical search in L2 comprehension than in L1 comprehensionThis research was approved by the ethics committee of the Spanish Ministry of Economy and Finance, which funded this study.We thank Silvia Blanch and Xavier Mayoral for their technical support, and Meritxell Ayguasanosa for assistance in testing participants. This research was funded by an FPI grant (BES-2012-056668) and two project grants (PSI2011-23033 and Consolider INGENIO CSD2007- 00012) awarded by the Spanish Government; by one grant from the Catalan Government (SGR 2009-1521); and by one grant from the European Research Council under the European Community’s Seventh Framework (FP7/2007-2013 Cooperation grant agreement 613465-AThEME). C.D.M. is supported by the IKERBASQUE institution and the Basque Center on Cognition, Brain and Language. A.C. is supported by the ICREA institution and the Center for Brain and Cognition

    Certainty relations between local and nonlocal observables

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    We demonstrate that for an arbitrary number of identical particles, each defined on a Hilbert-space of arbitrary dimension, there exists a whole ladder of relations of complementarity between local, and every conceivable kind of joint (or nonlocal) measurements. E.g., the more accurate we can know (by a measurement) some joint property of three qubits (projecting the state onto a tripartite entangled state), the less accurate some other property, local to the three qubits, become. We also show that the corresponding complementarity relations are particularly tight for particles defined on prime dimensional Hilbert spaces.Comment: 4 pages, no figure

    The effects of advanced maternal age on T- cell subsets at the maternal- fetal interface prior to term labor and in the offspring: a mouse study

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155904/1/cei13437.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155904/2/cei13437_am.pd

    Anomalous Hall conductivity control in Mn3_3NiN antiperovskite by epitaxial strain along the kagome plane

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    Antiferromagnetic manganese-based nitride antiperovskites, such as Mn3_3NiN, hold a triangular frustrated magnetic ordering over their kagome lattice formed by the Mn atoms along the (111)-plane. As such, frustration imposes a non-trivial interplay between the symmetric and asymmetric magnetic interactions, which can only reach equilibrium in a noncollinear magnetic configuration. Consequently, the associated electronic interactions and their possible tuning by external constraints, such as applied epitaxial strain, play a crucial role in defining the microscopic and macroscopic properties of such topological condensed matter systems. Thus, in the present work, we explored and explained the effect of the epitaxial strain imposed within the (111)-plane, in which the magnetic and crystallographic symmetry operations are kept fixed, and only the magnitude of the ionic and electronic interactions are tuned. We found a linear shifting in the energy of the band structure and a linear increase/decrease of the available states near the Fermi level with the applied strain. Concretely, the compression strain reduces the Mn-Mn distances in the (111) kagome plane but linearly increases the separation between the stacked kagome lattices and the available states near the Fermi level. Despite the linear controlling of the available states across the Fermi energy, the anomalous Hall conductivity shows a non-linear behavior where the σ111\sigma_{111} conductivity nearly vanishes for tensile strain. On the other hand, σ111\sigma_{111} fetches a maximum increase of 26\% about the unstrained structure for a compression value close to -1.5\%.This behavior found an explanation in the non-divergent Berry curvature within the kagome plane, which is increased for constraining but significantly reduced for expansion strain values..

    Absceso epidural cervical por peptostreptococcus anaerobius

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    Se presenta 1 caso de infección con absceso epidural a nivel cervical producido por un Peplostreptococcus anaerobius en 1 paciente en el que se realizó previamente una artrodesis C6-C7 por una hernia discal cervical. En la literatura no se han encontrado referencias bibliográficas de casos similares, por la etiología y la localización. Se discute la importancia de las infecciones por bacterias anaerobias en patología osteoarticular, métodos diagnósticos, así como su abordaje terapéutico.A case of postsurgical infection with cervical epidural abscess produced by Peptostreptococcus anaerobius is presented. The patient underwent previously a cervical arthrodesis (levels C6-C7) due to a discal herniation. A similar case has not been found in the review of the literature, taking into account its etiology and localization. It is discussed the importance of anerobic bacterial infections in osteoarticular pathology, and diagnostic and therapeutic means
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