266 research outputs found

    Inelastic neutron scattering investigation of the crystal field excitations of NdCo5

    Get PDF
    We present an inelastic neutron scattering study of the crystal electric field (CEF) levels in the intermetallic ferrimagnets RECo5 (RE=Nd and Y). In NdCo5, measurements at 5K reveal two levels at approximately 28.9 and 52.9 meV. Crystal-field calculations including the exchange field Bexc from the Co sites account for both of these, as well as the spectrum at temperatures above the spin-reorientation transition at ∼280 K. In particular, it is found that both a large hexagonal crystal field parameter A66(r6) and Bexc are required to reproduce the data, with the latter having a much larger value than that deduced from previous computational and experimental studies. Our study sheds light on the delicate interplay of terms in the rare-earth Hamiltonian of RECo5 systems, and is therefore expected to stimulate further experimental and computational work on the broader family of rare-earth permanent magnets

    Propuesta para la sustituci?n del combustible Di?sel en los veh?culos de transporte de pasajeros

    Get PDF
    La presente tesis propone un cambio de la matriz energ?tica en el transporte urbano de pasajeros, que consume combustible di?sel y en su mayor?a de importaci?n, Para tal efecto hemos seleccionado a la empresa de Transportes Unidos el Chino S.A. (ETUCHISA) como caso estudio y l?nea base para realizar una transici?n energ?tica al Gas Natural y/o bater?as el?ctricas, para ello se plantea evaluar lo siguiente: - Rentabilidad econ?mica del combustible di?sel, - Evaluaci?n del impacto ambiental de las alternativas, - Evaluaci?n de la sostenibilidad social de las alternativas, - Seleccionar la alternativa que permita sustituir el combustible di?sel. De las evaluaciones a los buses de transporte urbano de pasajeros, realizadas en t?rminos privados y sociales, se determina que los primeros 5 a?os de operaci?n es rentable el uso del combustible di?sel, posteriormente, desde el a?o 5 al a?o 20, el uso de buses a Gas Natural es m?s rentable y finalmente, desde el a?o 20 en adelante, el uso de Bater?as el?ctricas es definitivamente m?s rentable que las otras dos alternativas de combustible. Finalmente, proponemos que las entidades gubernamentales MINEM, MINAM y MTC realicen coordinaciones y pol?ticas p?blicas integradas para que de esta manera se elabore el plan estrat?gico para la transici?n energ?tica planteada

    IFNAR1-Signalling Obstructs ICOS-mediated Humoral Immunity during Non-lethal Blood-Stage Plasmodium Infection

    Get PDF
    Funding: This work was funded by a Career Development Fellowship (1028634) and a project grant (GRNT1028641) awarded to AHa by the Australian National Health & Medical Research Council (NHMRC). IS was supported by The University of Queensland Centennial and IPRS Scholarships. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

    Multi-isotopic and morphometric evidence for the migration of farmers leading up to the Inka conquest of the southern Andes

    Get PDF
    We present isotopic and morphometric evidence suggesting the migration of farmers in the southern Andes in the period AD 1270–1420, leading up to the Inka conquest occurring ~ AD 1400. This is based on the interdisciplinary study of human remains from archaeological cemeteries in the Andean Uspallata Valley (Argentina), located in the southern frontier of the Inka Empire. The studied samples span AD 800–1500, encompassing the highly dynamic Late Intermediate Period and culminating with the imperial expansion. Our research combines a macro-regional study of human paleomobility and migration based on a new strontium isoscape across the Andes that allows identifying locals and migrants, a geometric morphometric analysis of cranio-facial morphology suggesting separate ancestral lineages, and a paleodietary reconstruction based on stable isotopes showing that the migrants had diets exceptionally high in C4 plants and largely based on maize agriculture. Significantly, this migration influx occurred during a period of regional demographic increase and would have been part of a widespread period of change in settlement patterns and population movements that preceded the Inka expansion. These processes increased local social diversity and may have been subsequently utilized by the Inka to channel interaction with the local societies.Fil: Barberena, Ramiro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Interdisciplinario de Ciencias Básicas. - Universidad Nacional de Cuyo. Instituto Interdisciplinario de Ciencias Básicas; Argentina. Universidad Nacional de Cuyo. Facultad de Filosofía y Letras; ArgentinaFil: Menéndez, Lumila. Universitat Bonn; AlemaniaFil: le Roux, Petrus J.. University of Cape Town; SudáfricaFil: Marsh, Erik Johnson. Universidad Nacional de Cuyo. Facultad de Filosofía y Letras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Interdisciplinario de Ciencias Básicas. - Universidad Nacional de Cuyo. Instituto Interdisciplinario de Ciencias Básicas; ArgentinaFil: Tessone, Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geocronología y Geología Isotópica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geocronología y Geología Isotópica; ArgentinaFil: Novellino, Paula Silvana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mendoza. Museo de Ciencias Naturales y Antropológicas J. Cornelio Moyano; ArgentinaFil: Lucero, Gustavo. Universidad Católica de Temuco; ChileFil: Luyt, Julie. University of Cape Town; SudáfricaFil: Sealy, Judith. University of Cape Town; SudáfricaFil: Cardillo, Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Multidisciplinario de Historia y Ciencias Humanas; ArgentinaFil: Gasco, Alejandra Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Interdisciplinario de Ciencias Básicas. - Universidad Nacional de Cuyo. Instituto Interdisciplinario de Ciencias Básicas; Argentina. Universidad Nacional de Cuyo. Facultad de Filosofía y Letras; ArgentinaFil: Llano, Carina Lourdes. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Interdisciplinario de Ciencias Básicas. - Universidad Nacional de Cuyo. Instituto Interdisciplinario de Ciencias Básicas; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Aplicadas a la Industria; ArgentinaFil: Frigolé, Cecilia Andrea. Universidad Nacional de Cuyo. Facultad de Filosofía y Letras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Interdisciplinario de Ciencias Básicas. - Universidad Nacional de Cuyo. Instituto Interdisciplinario de Ciencias Básicas; ArgentinaFil: Guevara, Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mendoza. Museo de Ciencias Naturales y Antropológicas J. Cornelio Moyano; ArgentinaFil: Da Peña, Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mendoza. Museo de Ciencias Naturales y Antropológicas J. Cornelio Moyano; ArgentinaFil: Winocur, Diego Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Benítez, Anahí. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Cornejo, Luis. Universidad Alberto Hurtado; ChileFil: Falabella, Fernanda. Universidad de Chile; ChileFil: Méndez, César. Centro de Investigación en Ecosistemas de la Patagonia; ChileFil: Nuevo Delaunay, Amalia. Centro de Investigación en Ecosistemas de la Patagonia; ChileFil: Sanhueza, Lorena. Universidad de Chile; ChileFil: Santana Sagredo, Francisca. Pontificia Universidad Católica de Chile; ChileFil: Troncoso, Andrés. Universidad de Chile; ChileFil: Zárate, Sol. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Interdisciplinario de Ciencias Básicas. - Universidad Nacional de Cuyo. Instituto Interdisciplinario de Ciencias Básicas; ArgentinaFil: Duran, Victor Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Interdisciplinario de Ciencias Básicas. - Universidad Nacional de Cuyo. Instituto Interdisciplinario de Ciencias Básicas; Argentina. Universidad Nacional de Cuyo. Facultad de Filosofía y Letras; ArgentinaFil: Cortegoso, Valeria. Universidad Nacional de Cuyo. Facultad de Filosofía y Letras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Interdisciplinario de Ciencias Básicas. - Universidad Nacional de Cuyo. Instituto Interdisciplinario de Ciencias Básicas; Argentin

    A Severe Lack of Evidence Limits Effective Conservation of the World's Primates

    Get PDF
    Threats to biodiversity are well documented. However, to effectively conserve species and their habitats, we need to know which conservation interventions do (or do not) work. Evidence-based conservation evaluates interventions within a scientific framework. The Conservation Evidence project has summarized thousands of studies testing conservation interventions and compiled these as synopses for various habitats and taxa. In the present article, we analyzed the interventions assessed in the primate synopsis and compared these with other taxa. We found that despite intensive efforts to study primates and the extensive threats they face, less than 1% of primate studies evaluated conservation effectiveness. The studies often lacked quantitative data, failed to undertake postimplementation monitoring of populations or individuals, or implemented several interventions at once. Furthermore, the studies were biased toward specific taxa, geographic regions, and interventions. We describe barriers for testing primate conservation interventions and propose actions to improve the conservation evidence base to protect this endangered and globally important taxon

    Seasonal drought limits tree species across the Neotropics

    Get PDF
    AcceptedArticle in Press© 2016 Nordic Society Oikos.Within the tropics, the species richness of tree communities is strongly and positively associated with precipitation. Previous research has suggested that this macroecological pattern is driven by the negative effect of water-stress on the physiological processes of most tree species. This implies that the range limits of taxa are defined by their ability to occur under dry conditions, and thus in terms of species distributions predicts a nested pattern of taxa distribution from wet to dry areas. However, this 'dry-tolerance' hypothesis has yet to be adequately tested at large spatial and taxonomic scales. Here, using a dataset of 531 inventory plots of closed canopy forest distributed across the western Neotropics we investigated how precipitation, evaluated both as mean annual precipitation and as the maximum climatological water deficit, influences the distribution of tropical tree species, genera and families. We find that the distributions of tree taxa are indeed nested along precipitation gradients in the western Neotropics. Taxa tolerant to seasonal drought are disproportionally widespread across the precipitation gradient, with most reaching even the wettest climates sampled; however, most taxa analysed are restricted to wet areas. Our results suggest that the 'dry tolerance' hypothesis has broad applicability in the world's most species-rich forests. In addition, the large number of species restricted to wetter conditions strongly indicates that an increased frequency of drought could severely threaten biodiversity in this region. Overall, this study establishes a baseline for exploring how tropical forest tree composition may change in response to current and future environmental changes in this region.This paper is a product of the RAINFOR and ATDN networks and of ForestPlots.net researchers (http://www.forestplots.net). RAINFOR and ForestPlots have been supported by a Gordon and Betty Moore Foundation grant, the European Union’s Seventh Framework Programme (283080, ‘GEOCARBON’; 282664, ‘AMAZALERT’); European Research Council (ERC) grant ‘Tropical Forests in the Changing Earth System’ (T-FORCES), and Natural Environment Research Council (NERC) Urgency Grant and NERC Consortium Grants ‘AMAZONICA’ (NE/F005806/1) and ‘TROBIT’ (NE/D005590/1). Additional funding for fieldwork was provided by Tropical Ecology Assessment and Monitoring (TEAM) Network, a collaboration among Conservation International, the Missouri Botanical Garden, the Smithsonian Institution, and the Wildlife Conservation Society. A.E.M. receives a PhD scholarship from the T-FORCES ERC grant. O.L.P. is supported by an ERC Advanced Grant and a Royal Society Wolfson Research Merit Award. We thank Jon J. Lloyd, Chronis Tzedakis, David Galbraith, and two anonymous reviewers for helpful comments and Dylan Young for helping with the analyses. This study would not be possible without the extensive contributions of numerous field assistants and rural communities in the Neotropical forests. Alfredo Alarcón, Patricia Alvarez Loayza, Plínio Barbosa Camargo, Juan Carlos Licona, Alvaro Cogollo, Massiel Corrales Medina, Jose Daniel Soto, Gloria Gutierrez, Nestor Jaramillo Jarama, Laura Jessica Viscarra, Irina Mendoza Polo, Alexander Parada Gutierrez, Guido Pardo, Lourens Poorter, Adriana Prieto, Freddy Ramirez Arevalo, Agustín Rudas, Rebeca Sibler and Javier Silva Espejo additionally contributed data to this study though their RAINFOR participations. We further thank those colleagues no longer with us, Jean Pierre Veillon, Samuel Almeida, Sandra Patiño and Raimundo Saraiva. Many data come from Alwyn Gentry, whose example has inspired new generations to investigate the diversity of the Neotropics
    corecore