6,541 research outputs found

    HOMENS Trans(bordados): Experiências Juntas e Misturadas na Produção de Outras Masculinidades

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    O termo ―homem trans‖ refere-se a uma categoria política e social de pessoas que se recusam a ser definidas como mulheres, buscando por diversos motivos e processos identificarem-se com as masculinidades, transbordando normas de sexo e gênero. Pensando na pouca representatividade desses sujeitos nas pesquisas a respeito das transexualidades, o objetivo dessa dissertação é produzir experiências coletivas com homens trans, criando relações potencializantes com a vida e com os modos de viver; produzir encontros em que circulem histórias de vida que também dizem respeito aos coletivos que os atravessam; criar redes de solidariedade e amizades com eles, discutindo os modos e os métodos utilizados por esses sujeitos para a sua criação; conhecer as boas histórias, os movimentos de resistências e as transformações nas vidas dos homens trans, para além de sofrimentos ou mortificações em vida. O método deste trabalho é norteado pelos estudos cartográficos e dos cotidianos e foram feitas um total de cinco entrevistas com homens trans. O texto está dividido em quatro momentos que dialogam com temas que foram surgindo ao longo da pesquisa: Transviante pesquisar, em que abordo as propostas metodológicas para esse trabalho e como elas foram mudando ao longo dos dois anos de pesquisa; em Corpo trago alguns apontamentos sobre a produção do corpo trazido por homens trans da pesquisa; no capítulo Políticas apresento as políticas produzidas pelos homens trans para a implementação do Instituto Brasileiro de Transmasculinidades do Espírito Santo (IBRAT-ES), das produções autobiográficas e das pesquisas; e em Recortes apresento e problematizo alguns momentos importantes para produção de conhecimentos a respeito das transmasculinidades. Nos encontros e experiências com os homens trans, podemos ver um fiar de realidades que colocam esses mesmos sujeitos em movimentos desejantes na intenção de esculpir um novo corpo, um novo pensar e um novo existir. Muito mais do que conhecer a produção de sujeitos meramente sexualizados, observamos a produção da vida. Palavras-chave: homens trans; transmasculinidade; sexualidade; gênero; psicologia

    Location of the Energy Levels of the Rare-Earth Ion in BaF2 and CdF2

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    The location of the energy levels of rare-earth (RE) elements in the energy band diagram of BaF2 and CdF2 crystals is determined. The role of RE3+ and RE2+ ions in the capture of charge carriers, luminescence, and the formation of radiation defects is evaluated. It is shown that the substantial difference in the luminescence properties of BaF2:RE and CdF2:RE is associated with the location of the excited energy levels in the band diagram of the crystals

    Remotely sensed variables explain microhabitat selection and reveal buffering behaviours against warming in a climate-sensitive bird species

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    Fine-scale habitat selection modelling can allow a mechanistic understanding of habitat selection processes, enabling better assessments of the effects of climate and habitat changes on biodiversity. Remotely sensed data provide an ever-increasing amount of environmental and climatic variables at high spatio-temporal resolutions, and a unique opportunity to produce fine-scale habitat models particularly useful in challenging environments, such as high-elevation areas. Working at a 10-m spatial resolution, we assessed the value of remotely sensed data for investigating foraging habitat selection (in relation to topography, microclimate, land cover) in nestling-rearing white-winged snowfinch (Montifringilla nivalis), a high-elevation species highly sensitive to climate change. Adult snowfinches foraged at locations with intermediate vegetation cover and higher habitat heterogeneity, also avoiding extremely warm or extremely cold microclimates. Temperature interacted with other environmental drivers in defining habitat selection, highlighting trade-offs between habitat profitability and thermoregulation: snowfinches likely adopted mechanisms of behavioural buffering against physiologically stressful conditions by selecting for cooler, shaded and more snowy foraging grounds at higher temperatures. Our results matched those from previous studies based on accurate field measurements, confirming the species' reliance on climate-sensitive microhabitats (snow patches and low-sward grassland, in heterogeneous patches) and the usefulness of satellite-derived fine-scale modelling. Habitat suitability models built on remotely sensed predictors can provide a cost-effective method for periodic monitoring of species' habitats both at fine grain and over large extents. Fine-scale models also enhance our understanding of the actual drivers of (micro)habitat selection and of possible buffering behaviours against warming, allowing more accurate and robust distribution models, finer predictions of potential future changes and carefully targeted conservation strategies and habitat management

    Ecological factors affecting foraging behaviour during nestling rearing in a high-elevation species, the White-winged Snowfinch (Montifringilla nivalis)

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    During breeding, parents of avian species must increase their foraging efforts to collect food for their offspring, besides themselves. Foraging trips are thus a key aspect of the foraging ecology of central-place foragers when rearing their offspring. However, studies of the foraging ecology of high-elevation specialists inhabiting harsh environments are scarce. Here we report for the first time quantitative information on ecological determinants of foraging trips in the White-winged Snowfinch (Montifringilla nivalis), a high-elevation specialist threatened by climate warming. We focused on seasonal, meteorological, habitat and social factors affecting distance and duration of foraging trips performed during nestling rearing, recorded by visual observations in the Italian Alps. Based on 309 foraging trips from 35 pairs, we found that trips lasted 6.12 min and foraging areas were located at 175 m from the nest site on average. Trip duration was affected by snow cover (longer at intermediate cover), distance travelled and wind, while distance travelled was affected by snow cover (being higher at intermediate cover) and trip duration. Foraging individuals thus travelled farther and spent more time at areas characterized by intermediate snow cover, implying the presence of snow margins. It is likely that at such snow patches/margins snowfinches collected food for self-maintenance, besides that for their offspring, or collected more food items. Any reduction of snow cover during the breeding season, as expected under current climate warming, will severely alter foraging habitat suitability. Conserving suitable foraging habitats in the nest surroundings will be crucial to buffer such negative impacts

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    A genus at risk: Predicted current and future distribution of all three Lagopus species reveal sensitivity to climate change and efficacy of protected areas

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    Aim: Cold-adapted species are considered vulnerable to climate change. However, our understanding of how climate-induced changes in habitat and weather patterns will influence habitat suitability remains poorly understood, particularly for species at high latitudes or elevations. Here, we assessed potential future distributions for a climate-sensitive genus, Lagopus, and the effectiveness of protected areas in tracking shifting distributions. Location: British Columbia, Canada. Methods: Using community science observations from 1970 to 2020, we built species distribution models for white-tailed (L. leucura), rock (L. muta) and willow ptarmigan (L. lagopus) across British Columbia, a globally unique region harbouring all three ptarmigan species. We assessed the impact of climate (direct) and climate-induced habitat change (indirect) on potential future distributions of ptarmigan. Results: White-tailed and rock ptarmigan were associated with colder temperatures and tundra-like open habitats and willow ptarmigan with open, shrub habitats. Future projections based on climate and vegetation scenarios indicated marked losses in suitable habitat by the 2080s (RCP +8.5 W/m2), with range declines of 85.6% and 79.5% for white-tailed and rock ptarmigan, respectively, and a lower 61.3% for willow ptarmigan. Predicted current and future suitable habitat occurred primarily outside of current protected areas (67%–82%), yet range size declined at a less pronounced rate within protected areas suggesting a capacity to buffer habitat loss. Main conclusions: Ptarmigan are predicted to persist at higher elevations and latitudes than currently occupied, with the magnitude of elevation shifts consistent with trends observed elsewhere in the Holarctic. Our spatially explicit assessment of potential current and future distributions of ptarmigan species provides the first comprehensive evaluation of climate change effects on the distribution of three congeneric, cold-adapted species with different habitat preferences and life-history traits. We also highlight the potential role of protected areas in preserving suitable future sites for ptarmigan and other climate-sensitive or high-elevation species

    NMR and dc-susceptibility studies of NaVGe2O6

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    We report the results of measurements of the dc magnetic susceptibility chi(T) and of the 23Na nuclear magnetic resonance (NMR) response of NaVGe2O6, a material in which the V ions form a network of interacting one-dimensional spin S=1 chains. The experiments were made at temperatures between 2.5 and 300 K. The chi(T) data suggest that the formation of the expected low-temperature Haldane phase is intercepted by an antiferromagnetic phase transition at 18 K. The transition is also reflected in the 23Na NMR spectra and the corresponding spin-lattice relaxation rate 1/T1(T). In the ordered phase, 1/T1(T) decreases by orders of magnitude with decreasing temperature, indicating the formation of a gap of the order of 12 K in the magnetic excitation spectrum.Comment: 10 pages, 15 figures; v2 with minor revisions of the tex

    Nb3_3Sn conductor development and characterization for NED

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    The main purpose of Next European Dipole (NED) project is to design and to build an Nb3_{3}Sn ~ 15 T dipole magnet. Due to budget constraints, NED is mainly focused on superconducting cable development and production. In this work, an update is given on the NED conductor development by Alstom-MSA and SMI, which uses, respectively, Internal-Tin-Diffusion and Powder-In-Tube methods, with the aim of reaching a non-copper critical current density of ~ 3000 A/mm2 at 12 T and 4.2 K. Characterization results, including critical current and magnetization data, are presented and discussed, as well, for conductors already developed by both companies for this project. SMI succeeded to produce a strand with 50 µm diameter filaments and with a critical current of ~ 1400 A at 4.2 K and 12 T, corresponding to a non-copper critical current density of ~ 2500 A/mm2. Cabling trials with this strand were successfully carried out at LBNL
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