108 research outputs found

    The Holographic Dual of 2+1 Dimensional QFTs with N=1 SUSY and Massive Fundamental Flavours

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    The Maldacena Nastase solution is generalised to include massive fundamental matter through the addition of a flavour profile. This gives a holographic dual to N=1 SYM-CS with massive fundamental matter with a singularity free IR. We study this solution in some detail confirming confinement and asymptotic freedom. A recently proposed solution generating technique is then applied which results in a new type-IIA supergravity solution. In a certain limit the geometry of this solution is asymptotically AdS_4X Y, where Y is the metric at the base of the Bryant-Salamon G_2 cone, which has topology S^3XS^3.Comment: 31 pages plus appendices, 6 figures. v3: Typos corrected, version to appear in JHE

    Modelo conceptual para la reducción del riesgo de desastres: contribución al desarrollo local sostenible

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    Se analizó el riesgo de desastres en el contexto naturaleza-cultura-desarrollo local y se identificaron elementos que forman su modelo conceptual. La previsión de ese riesgo —en sus facetas social y regional— se abordó como construcción social dinámica y cambiante, que exige gestión del conocimiento y estrategias de comunicación. Se propuso un modelo conceptual para reducir el riesgo de desastres e introducir cultura de prevención a nivel local

    [14] Una aportación para las “escuelas sostenibles” en la década de la educación para el desarrollo sostenible

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    En el contexto de la Década de la Educación para el Desarrollo sostenible presentamos nuestra aportación a las “Escuelas Sostenibles”. Ésta surge como fruto de la reflexión después de una investigación realizada en torno a una experiencia concreta: “Ecocentros de Extremadura”, con el fin de contribuir al necesario proceso madurativo de las mismas. Con ello estaremos más cerca de lograr hacer una escuela coherente con los retos de la educación ambiental para el siglo XXI.Palabras clave: Escuelas sostenibles; ecoauditorías escolares; investigación en educación ambiental; práctica educativa en la escuela.A contribution to "sustainable schools" in the decade of education for sustainable developmentAs part of the context of the Decade of Education for Sustainable Development, we present our contribution to "Sustainable Schools". It arose as a result of reflection following as study conducted on a specific experience, "The 'Ecocentros' of Extremadura", with the aim of furthering the necessary maturation process of sustainable schools, and bringing us closer to achieving a school that is coherent with the challenges of environmental education for the XXI century.Keywords: Sustainable schools; school environmental audits, environmental education research; educational practice in the school

    Evaluation of bacterial adherence of clinical isolates of Staphylococcus sp. using a competitive model: An in vitro approach to the "race for the surface" theory

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    Objectives Implant-related infection is one of the most devastating complications in orthopaedic surgery. Many surface and/or material modifications have been developed in order to minimise this problem; however, most of the in vitro studies did not evaluate bacterial adhesion in the presence of eukaryotic cells, as stated by the 'race for the surface' theory. Moreover, the adherence of numerous clinical strains with different initial concentrations has not been studied. Methods We describe a method for the study of bacterial adherence in the presence of preosteoblastic cells. For this purpose we mixed different concentrations of bacterial cells from collection and clinical strains of staphylococci isolated from implant-related infections with preosteoblastic cells, and analysed the minimal concentration of bacteria able to colonise the surface of the material with image analysis. Results Our results show that clinical strains adhere to the material surface at lower concentrations than collection strains. A destructive effect of bacteria on preosteoblastic cells was also detected, especially with higher concentrations of bacteria. Conclusions The method described herein can be used to evaluate the effect of surface modifications on bacterial adherence more accurately than conventional monoculture studies. Clinical strains behave differently than collection strains with respect to bacterial adherence.This work was funded by the following grants from the Spanish MINECO (MAT2013- 48224-C2-2-R and MAT2013-48224-C2-1-R). M. Martínez-Pérez reports funding received from EFORT 2015 congress: travel supported by PFIZER, which is related to this article. J. Esteban and E. Gómez-Barrena report funding received from several companies for travel, expenses and grants, none of which is related to this articl

    D3/D7 Quark-Gluon Plasma with Magnetically Induced Anisotropy

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    We study the effects of the temperature and of a magnetic field in the setup of an intersection of D3/D7 branes, where a large number of D7 branes is smeared in the transverse directions to allow for a perturbative solution in a backreaction parameter. The magnetic field sources an anisotropy in the plasma, and we investigate its physical consequences for the thermodynamics and energy loss of particles probing the system. In particular we comment on the stress-energy tensor of the plasma, the propagation of sound in the directions parallel and orthogonal to the magnetic field, the drag force of a quark moving through the medium and jet quenching.Comment: 29 pages + appendices, 5 figures. v2 Version to appear in JHEP, with minor revisions, references added and typos correcte

    The Non-SUSY Baryonic Branch: Soft Supersymmetry Breaking of N=1 Gauge Theories

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    We study a non-supersymmetric deformation of the field theory dual to the baryonic branch of Klebanov-Strassler. Using a combination of analytical (series expansions) and numerical methods we construct non-supersymmetric backgrounds that smoothly interpolate between the desired UV and IR behaviors. We calculate various observables of the field theory and propose a picture of soft breaking by gaugino masses that is consistent with the various calculations on the string side.Comment: 32 pages plus many appendixes. One figur

    Open and Hidden Charm Production in 920 GeV Proton-Nucleus Collisions

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    The HERA-B collaboration has studied the production of charmonium and open charm states in collisions of 920 GeV protons with wire targets of different materials. The acceptance of the HERA-B spectrometer covers negative values of xF up to xF=-0.3 and a broad range in transverse momentum from 0.0 to 4.8 GeV/c. The studies presented in this paper include J/psi differential distributions and the suppression of J/psi production in nuclear media. Furthermore, production cross sections and cross section ratios for open charm mesons are discussed.Comment: 5 pages, 9 figures, to be published in the proceedings of the 6th International Conference on Hyperons, Charm & Beauty Hadrons (BEACH04), Chicago, IL, June 27 - July 3, 200

    Search for the Flavor-Changing Neutral Current Decay D0μ+μD^0 \to \mu^+\mu^- with the HERA-B Detector

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    We report on a search for the flavor-changing neutral current decay D0μ+μD^0 \to \mu^+\mu^- using 50×10650 \times 10^6 events recorded with a dimuon trigger in interactions of 920 GeV protons with nuclei by the HERA-B experiment. We find no evidence for such decays and set a 90% confidence level upper limit on the branching fraction Br(D0μ+μ)<2.0×106Br(D^0 \to \mu^+\mu^-) <2.0 \times 10^{-6}.Comment: 17 pages, 4 figures (of which 1 double), paper to be submitted to Physics Letters

    Dualising the baryonic branch: Dynamic SU(2) and confining backgrounds in IIA

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    In this paper we construct and examine new supersymmetric solutions of massive IIA supergravity that are obtained using non-Abelian T-duality applied to the Baryonic Branch of the Klebanov-Strassler background. The geometries display SU(2) structure which we show flows from static in the UV to dynamical in the IR. Confinement and symmetry breaking are given a geometrical interpretation by this change of structure. Various field theory observables are studied, suggesting possible ways to break conformality and flow in N=1 TN and related field theories
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