7 research outputs found

    Optical spectroscopy of Yb3+ centers in BaMgF4 ferroelectric crystal

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    The following article appeared in Journal of Applied Physics 110.6 (2011): 063102 and may be found at http://scitation.aip.org/content/aip/journal/jap/110/6/10.1063/1.3638040We report on the optical characterization of Yb3+ doped BaMgF4+ nonlinear fluoride crystal grown by the Czochralski technique. Low temperature absorption spectroscopy reveals that Yb3+ incorporates into the matrix at four well differentiated centers. High resolution site selective experiments have been performed to determine the energy level schemes associated with the major Yb3+ centers detected in the system. The fluorescence decay times recorded at 10 K under selective excitation are analyzed for each Yb3+ center. The spectroscopic behavior of the codoped Yb3+:Na+:BaMgF4+ system has been also investigated. Codoping with Na+ eliminates two Yb3+ centers present in the singly doped Yb3+:BaMgF 4+ crystal. The charge compensation mechanisms and site location for Yb3+ in the fluoride matrix are discussedThis work has been supported by Spanish MICINN under Contract Nos. MAT2010-17443 and MAT2009-06580, Comunidad de Madrid under Grant No. PHAMA S2009/MAT-1756 and Universidad Autónoma de Madrid under Contract No. CCG10-UAM/MAT-5290

    Current threats faced by Neotropical parrot populations

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    Made available in DSpace on 2018-12-11T16:49:29Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-10-01Consejo Nacional de Investigaciones Científicas y TécnicasAgencia Nacional de Promoción Científica y TecnológicaPsittaciformes (parrots, cockatoos) are among the most endangered birds, with 31% of Neotropical species under threat. The drivers of this situation appear to be manifold and mainly of anthropogenic origin. However, this assessment is based on the last extensive consultation about the conservation situation of parrots carried out in the 1990s. Given the rapid development of anthropogenic threats, updated data are needed to strategize conservation actions. Using a population approach, we addressed this need through a wide-ranging consultation involving biologists, wildlife managers, government agencies and non-governmental conservation organizations. We gathered up-to-date information on threats affecting 192 populations of 96 Neotropical parrot species across 21 countries. Moreover, we investigated associations among current threats and population trends. Many populations were affected by multiple threats. Agriculture, Capture for the Pet Trade, Logging, each of them affected > 55% of the populations, suggesting a higher degree of risk than previously thought. In contrast to previous studies at the species level, our study showed that the threat most closely associated with decreasing population trends is now Capture for the local Pet Trade. Other threats associated with decreasing populations include Small-holder Farming, Rural Population Pressure, Nest Destruction by Poachers, Agro-industry Grazing, Small-holder Grazing, and Capture for the international Pet Trade. Conservation actions have been implemented on < 20% of populations. Our results highlight the importance of a population-level approach in revealing the extent of threats to wild populations. It is critical to increase the scope of conservation actions to reduce the capture of wild parrots for pets.Instituto Multidisciplinario sobre Ecosistemas y Desarrollo Sustentable CONICET—Universidad Nacional del Centro de la Provincia de Buenos AiresJustus-Liebig-Universität Giessen Department of Animal Ecology and SystematicsTexas A&M University Schubot Exotic Bird Health Center Department of Veterinary Pathobiology College of Veterinary MedicineSociedade de Pesquisa em Vida Selvagem e Educação AmbientalUniversidade Federal de SergipePrograma Lapa Verde Centro Científico TropicalFacultad de Ciencias Naturales y Museo Universidad Nacional de La PlataArea de Conservación Pacífico Central ACOPAC Programa de Vida SilvestreWildlife Conservation SocietyAarhus UniversityGrupo de Ecología Conservación de Islas A.C. (GECI)University of California Department of Environment Science Policy & ManagementUniversidad Nacional Federico VillarrealUniversidade Federal de GoiásInstituto Venezolano de Investigaciones CientíficasProyecto Selva de Pino ParanáUnidos por las Guacamayas A. C.SELVA: Investigación para la conservación en el NeotrópicoInstituto Nacional de Tecnología AgropecuariaUniversity of BrasíliaUniversidade Federal da Paraíba Centro de Ciências Exatas e da NaturezaCentro Nacional de Pesquisa e Conservação de Aves Silvestres/ICMBioUniversidade Federal do Pará Instituto de Ciências BiológicasGuyra ParaguayUniversity of Colorado Department of Integrative BiologyThe World Parrot TrustBirdsCaribbeanFundacion del RioUniversitat de BarcelonaSociedad Conservacionista Audubon de VenezuelaUniversidad de Sancti Spíritus ¨José Martí Pérez¨Estación Biológica de Doñana CSICFundación Pro-BosqueCompañeros en Vuelo PIF-SVInstituto de Investigaciones Marinas y Costeras CONICET—Universidad Nacional de Mar del PlataUniversity of North Texas Biological SciencesOne Earth ConservationInstituto Espaço SilvestreUniversidade do Estado do AmazonasNational Aviary Conservation and Field ResearchUniversity of Cape TownBirdlife InternationalPaso PacíficoUniversidade de Passo FundoBiola UniversityMinisterio del Ambiente y los Recursos Naturales (MARENA)Universidad Michoacana de San Nicolas de HidalgoFundação Universidade Federal de Mato Grosso do SulAQUASISFundación Botánica y Zoológica de BarranquillaProvitaCIT Jujuy CONICET—UNJuFundación de Ciencias para el Estudio y la Conservación de la Biodiversidad (INCEBIO)UNESP Instituto de Biociências de BotucatuUniversidad Nacional Autónoma de México Estación Biología Chamela Instituto de BiologíaVinculación Interdisciplinaria para el Desarrollo Ambiental y lo SocialMesserli Research Institute University of Veterinary MedicineMuseo Noel Kempff MercadoGobierno Autónomo Departamental de Santa CruzUniversidad Autónoma de SinaloaMuseu de Zoologia da Universidade de Sao Paulo (MZUSP)University of Freiburg Evolutionary Biology and Animal EcologyMuseu de História Natural Capão da ImbuiaFundação Neotropica do BrasilCEMAVE: Centro Nacional de Pesquisa para a Conservação das Aves SilvestresCORBIDIAsociación Fauna ForeverUniversity of San Francisco Xavier de ChuquisacaUniversidad Nacional Autónoma de México Museo de Zoología Facultad de CienciasU.S. Fish and Wildlife Service Puerto Rican Parrot Recovery ProgramEcho Parrots and PeopleCátedra de Ecología General y Recursos Naturales Universidad Nacional Arturo JauretcheFundación para la Investigación y Conservación de los Loros en Bolivia (CLB)Instituto de Bio y Geociencias del NOA CONICETLaboratorio Nacional de Análisis y Síntesis Ecológica Universidad Nacional Autónoma de MéxicoDepto. de Estudios Ambientales Universidad Simón BolívarUNESP Instituto de Biociências de BotucatuConsejo Nacional de Investigaciones Científicas y Técnicas: CONICET-PIP 112-201501-0598Agencia Nacional de Promoción Científica y Tecnológica: FONCyT-PICT 2015-228

    II. Conflictos entre felinos y humanos en América Latina.

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    Este libro contó con el liderazgo del Instituto Humboldt y de las Fundaciones Herencia Ambiental Caribe y Panthera. En 32 capítulos se recoge el esfuerzo de 77 instituciones y 110 autores que representan 18 países y abordan el conflicto entre humanos y felinos en América Latina. Es la compilación más completa que se ha elaborado acerca del tema en Latinoamérica, involucrando el análisis, la planificación, el manejo y la resolución de los conflictos entre humanos y felinos.BogotáCiencias de la Biodiversida

    Quantum Mechanical Studies of Large Metal, Metal Oxide, and Metal Chalcogenide Nanoparticles and Clusters

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    Current threats faced by Neotropical parrot populations

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    Berkunsky I, Quillfeldt P, Brightsmith DJ, et al. Current threats faced by Neotropical parrot populations. Biological Conservation. 2017;214:278-287.Psittaciformes (parrots, cockatoos) are among the most endangered birds, with 31% of Neotropical species under threat. The drivers of this situation appear to be manifold and mainly of anthropogenic origin. However, this assessment is based on the last extensive consultation about the conservation situation of parrots carried out in the 1990s. Given the rapid development of anthropogenic threats, updated data are needed to strategize conservation actions. Using a population approach, we addressed this need through a wide-ranging consultation involving biologists, wildlife managers, government agencies and non-governmental conservation organizations. We gathered up-to-date information on threats affecting 192 populations of 96 Neotropical parrot species across 21 countries. Moreover, we investigated associations among current threats and population trends. Many populations were affected by multiple threats. Agriculture, Capture for the Pet Trade, Logging, each of them affected > 55% of the populations, suggesting a higher degree of risk than previously thought. In contrast to previous studies at the species level, our study showed that the threat most closely associated with decreasing population trends is now Capture for the local Pet Trade. Other threats associated with decreasing populations include Small-holder Farming, Rural Population Pressure, Nest Destruction by Poachers, Agro-industry Grazing, Small-holder Grazing, and Capture for the international Pet Trade. Conservation actions have been implemented on < 20% of populations. Our results highlight the importance of a population-level approach in revealing the extent of threats to wild populations. It is critical to increase the scope of conservation actions to reduce the capture of wild parrots for pets
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