119 research outputs found

    ContribuciĂłn al conocimiento de las comunidades de Oryzopsi-Anthirrinetum granitici corr. Rivas-MartĂ­nez 1969, del Centro y Sur de Portugal

    Get PDF
    Wall communities from 42 localities of the Portuguese Luso-Extremadurense Chrological Province are studied. A big poverty of Parietarietea eurosiberian elements and a great deal of nitrophilous mediterranean ones is observed, so the .communities are included in the Oryzopsi-Anthirrinetum gran itici corr. Rivas-Martínez 1969, which represents the Parietarietea Class from the SW Iberian Peninsule. Whithin this association, three new subassociations are described for the first time.Se estudian las comunidades de muros y paredes rurales y urbanos en 42 localidades de los sectores portugueses de la provincia corológica luso-extremadurense. Se observa una notable pobreza en elementos genuinos de Parietarietea, eurosiberianos, y una gran abundancia de especies compañeras de área mediterránea. Por ello se ubican dichas comunidades en la Ass. Oryzopsi-Anthirrineturn granitici corr. Rivas-Martínez 1969, que define la Parietarietea finícola del SW ibérico. Dentro de esta asociación, se describen por primera vez tres pautas de variabilidad con rango de subasociación

    La Situación educativa de la población infantil emberá en condición de desplazamiento. El caso del Colegio distrital Agustín Nieto en Bogotá

    Get PDF
    Siendo estudiantes de pregrado de la Universidad Nacional de Colombia, decidimos reunirnos como un grupo de investigación académica. Además de tener una motivación académica, entramos en un posterior compromiso por nuestra labor debido a la información que pudimos conocer, por medio de nuestras conversaciones y posteriores entrevistas con las profesoras, actividades con los niños y diálogos con los padres y miembros adultos de la comunidad Emberá, y las entrevistas de tipo informal y formal con los miembros de la institución educativa, conocimiento que nos logró mostrar distintas problemáticas. Con respecto al marco teórico trabajado, nos adentramos en el objeto de investigación a partir de la historia de la comunidad Emberá dentro de la producción académica colombiana y en trabajos realizados en conjunto con las organizaciones indígenas, consejos regionales, cabildos específicos e instituciones del estado en investigación; nos enfocamos en aspectos referentes a la comunidad étnica, al desplazamiento forzado y a criterios etnoeducativos

    Respuesta que por su parte da el Duque de Osuna al num. VI. del Robespierre

    Get PDF
    BHR/C-043-082 (5)34159BHR/C-043-082 (5)4-22-3-53Digitalización Fondo Granadin

    Energy dependence of ϕ meson production at forward rapidity in pp collisions at the LHC

    Get PDF
    The production of ϕ\phi mesons has been studied in pp collisions at LHC energies with the ALICE detector via the dimuon decay channel in the rapidity region 2.5<y<42.5< y < 4. Measurements of the differential cross section d2σ/dydpT\mathrm{d}^2\sigma /\mathrm{d}y \mathrm{d}p_{\mathrm {T}} are presented as a function of the transverse momentum (pTp_{\mathrm {T}}) at the center-of-mass energies s=5.02\sqrt{s}=5.02, 8 and 13 TeV and compared with the ALICE results at midrapidity. The differential cross sections at s=5.02\sqrt{s}=5.02 and 13 TeV are also studied in several rapidity intervals as a function of pTp_{\mathrm {T}}, and as a function of rapidity in three pTp_{\mathrm {T}} intervals. A hardening of the pTp_{\mathrm {T}}-differential cross section with the collision energy is observed, while, for a given energy, pTp_{\mathrm {T}} spectra soften with increasing rapidity and, conversely, rapidity distributions get slightly narrower at increasing pTp_{\mathrm {T}}. The new results, complementing the published measurements at s=2.76\sqrt{s}=2.76 and 7 TeV, allow one to establish the energy dependence of ϕ\phi meson production and to compare the measured cross sections with phenomenological models. None of the considered models manages to describe the evolution of the cross section with pTp_{\mathrm {T}} and rapidity at all the energies.publishedVersio

    Elliptic and triangular flow of (anti)deuterons in Pb-Pb collisions at sNN =5.02 TeV

    Get PDF
    The measurements of the (anti)deuteron elliptic flow (v2) and the first measurements of triangular flow (v3) in Pb-Pb collisions at a center-of-mass energy per nucleon-nucleon collision √sNN = 5.02 TeV are presented. A mass ordering at low transverse momentum (pT) is observed when comparing these measurements with those of other identified hadrons, as expected from relativistic hydrodynamics. The measured (anti)deuteron v2 lies between the predictions from the simple coalescence and blast-wave models, which provide a good description of the data only for more peripheral and for more central collisions, respectively. The mass number scaling, which is violated for v2, is approximately valid for the (anti)deuterons v3. The measured v2 and v3 are also compared with the predictions from a coalescence approach with phase-space distributions of nucleons generated by IEBEVISHNU with AMPT initial conditions coupled with URQMD, and from a dynamical model based on relativistic hydrodynamics coupled to the hadronic afterburner SMASH. The model predictions are consistent with the data within the uncertainties in midcentral collisions, while a deviation is observed in the most central collisions

    Coherent psi (2S) photo-production in ultra-peripheral Pb-Pb collisions at root s(NN)=2.76TeV

    Get PDF
    We have performed the first measurement of the coherent psi(2S) photo-production cross section in ultraperipheral Pb-Pb collisions at the LHC. This charmonium excited state is reconstructed via the psi(2S) -> l(+)l(-) and ->(2S) -> J/psi pi(+)pi(-) decays, where the J/psi decays into two leptons. The analysis is based on an event sample corresponding to an integrated luminosity of about 22 mu b(-1). The cross section for coherent psi(2S) production in the rapidity interval -0.9 <y <0.9is d sigma(coh)(psi(2S))/dy = 0.83 +/- 0.19 (stat+syst) mb. The psi(2S) to J/psi coherent cross section ratio is 0.34(-0.07)(+0.08)(stat+syst). The obtained results are compared to predictions from theoretical models. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V.Peer reviewe

    Production of omega mesons in pp collisions at s=7 TeV

    Get PDF
    The invariant differential cross section of inclusive omega (782) meson production at midrapidity (|y| pi+pi-pi 0 decay channel. The measured omega production cross section is compared to various calculations: PYTHIA 8.2 Monash 2013 describes the data, while PYTHIA 8.2 Tune 4C overestimates the data by about 50%. A recent NLO calculation, which includes a model describing the fragmentation of the whole vector-meson nonet, describes the data within uncertainties below 6 GeV/c, while it overestimates the data by up to 50% for higher pT. The omega/pi 0 ratio is in agreement with previous measurements at lower collision energies and the PYTHIA calculations. In addition, the measurement is compatible with transverse mass scaling within the measured pT range and the ratio is constant with C omega/pi 0=0.67 +/- 0.03(stat) +/- 0.04(sys) above a transverse momentum of 2.5 GeV/c.Peer reviewe
    • 

    corecore