3,983 research outputs found

    Do non-state actors influence climate change policy? Evidence from the Brazilian nationally determined contributions for COP21

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    Participation in democratic regimes has been a central issue in foreign policy (FP) studies. This article seeks to contribute to the empirical discussion about FP participation through the analysis of the public consultation process conducted by the Brazilian Ministry of Foreign Affairs with non-state actors in the context of the preparations for the Paris Climate Agreement (2015). We employed automated text analysis using Python and R qualifying open responses submitted to the questionnaire launched at the first round of the consultations process and comparing them to the official document presented by Brazil establishing its own carbon emission targets. We found that the Brazilian academia members had a relevant influence on the content of the final document presented by Brazil, strengthening the literature on the importance of the epistemic community to environmental politics and raising new questions on the paths of foreign policy influence

    Late Pleistocene echimyid rodents (Rodentia, Hystricognathi) from northern Brazil

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    Echimyidae (spiny rats, tree rats and the coypu) is the most diverse family of extant South American hystricognath rodents (caviomorphs). Today, they live in tropical forests (Amazonian, coastal and Andean forests), occasionally in more open xeric habitats in the Cerrado and Caatinga of northern South America, and open areas across the southern portion of the continent (Myocastor). The Quaternary fossil record of this family remains poorly studied. Here, we describe the fossil echimyids found in karst deposits from southern Tocantins, northern Brazil. The analyzed specimens are assigned to Thrichomys sp., Makalata cf. didelphoides and Proechimys sp. This is the first time that a fossil of Makalata is reported. The Pleistocene record of echimyids from this area is represented by fragmentary remains, which hinders their determination at specific levels. The data reported here contributes to the understanding of the ancient diversity of rodents of this region, evidenced until now in other groups, such as the artiodactyls, cingulates, carnivores, marsupials, and squamate reptiles.Facultad de Ciencias Naturales y Muse

    Exploring different pretreatment methodologies for allowing microalgae growth in undiluted piggery wastewater

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    The overapplication of manure on agricultural soils leads to nitrogen and phosphorus discharge into the aquatic environment, resulting in serious eutrophication problems and decreased water quality. Piggery wastewater (PWW) can be treated by microalgae to recycle nutrients, but the toxic levels of ammonia and organic matter hinder their growth. Fresh water is usually used to dilute PWW, but it is a scarce resource. The implementation of a pretreatment step before microalgae-based treatment could make PWW suitable for microalgae growth. Electrocoagulation, ammonia stripping, photo-Fenton, and constructed wetlands were evaluated as pretreatment methods to reduce ammonia, chemical oxygen demand (COD), color, and total suspended solids. Moreover, the pretreated PWWs were tested to grow the microalga Tetradesmus obliquus. Photo-Fenton showed the best results among the other pretreatments, achieving removal efficiencies above 90%, except for ammonia. This resulted in T. obliquus being capable of growing on undiluted PWW, even at higher ammonia levels, achieving similar biomass productivity to synthetic medium (66.4 ± 17.8 mg·L−1·day−1 and 60.1 ± 10.4 mg·L−1·day−1, respectively) almost doubling with pH control (116.5 mg·L−1·day−1). Thus, this pretreatment seems to be the most promising one to incorporate into microalgae-based treatment systems and must be further explored.info:eu-repo/semantics/publishedVersio

    Write-erase and read paper memory transistor

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    Applied Physics Letters, Vol.93, issue 20We report the architecture and the performances of a memory based on a single field-effect transistor built on paper able to write-erase and read. The device is composed of natural multilayer cellulose fibers that simultaneously act as structural support and gate dielectric; active and passive multicomponent amorphous oxides that work as the channel and gate electrode layers, respectively,complemented by the use of patterned metal layers as source/drain electrodes. The devices exhibit a large counterclockwise hysteresis associated with the memory effect, with a turn-on voltage shift between 1 and −14.5 V, on/off ratio and saturation mobilities of about 104 and 40 cm2 V−1 s−1, respectively, and estimated charge retention times above 14 000 h

    Formalizando algoritmos concorrentes

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    Este trabalho mostra uma forma de pensar concorrente. São utilizados algoritmos de grafos, algoritmo do menor caminho, para mostrar desde a especificação até a implementação de algoritmos concorrentes. Objetiva-se mostrar uma outra forma de ensinar a concorrência, sua teoria, propriedades e a implementação de algoritmos concorrentes. Existem muitas áreas do conhecimento que necessitam e outras que podem se beneficiar do Processamento de Alto Desempenho (PAD), incluindo aí a concorrência. E ao mesmo tempo, são poucos os profissionais que possuem conhecimento para usar o PAD como um meio para solucionar problemas. Neste trabalho se apresenta a relação entre a especificação formal de programas concorrentes e a aplicação prática através das propriedades básicas dos programas paralelos.This work presents a way to think concurrent. We use graphs algorithms, shortest path, to show since specification thru concurrent algorithms implementation. We want to show another way to teach concurrency, theory, properties, and concurrent algorithms implementation. There are many knowledge areas that need High Performance Computing (HPC), including concurrent programming, and others that benefit with it. And at same time, there aren’t many people that have knowledge to use HPC as a way to solve problems. In this work we present a relation between concurrent formal specification and practical application thru the basic properties of parallel programs.Eje: Programación concurrenteRed de Universidades con Carreras en Informática (RedUNCI

    Negative effects of ant-plant interaction on pollination: costs of a mutualism

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    The mutualism of ants and extrafloral nectary (EFN)-bearing plants is known to reduce rates of herbivory. However, ants may have negative impacts on other mutualisms such as pollination, constituting an indirect cost of a facultative mutualism. For instance, when foraging on or close to reproductive plant parts ants might attack pollinators or inhibit their visits. We tested the hypothesis that ants on EFN-bearing plants may negatively influence pollinator behavior, ultimately reducing plant fitness (fruit set). The study was done in a reserve at Brazilian savannah using the EFN-bearing plant Banisteriopsis malifolia (Malpighiaceae). The experimental manipulation was carried out with four groups: control (free visitation of ants), without ants (ant-free branches), artificial ants (isolated branches with artificial ants on flowers) and plastic circles (isolated branches with plastic circles on flowers). We made observations on flower visitors and their interactions, and measured fruit formation as a proxy for plant fitness. Our results showed that pollinators hesitated to visit flowers with artificial ants, negatively affecting pollination, but did not hesitate to visit flowers with plastic circles, suggesting that they recognize the specific morphology of the ants. Pollinators spent more time per flower on the ant-free branches, and the fruiting rate was lower in the group with artificial ants. Our results confirm an indirect cost in this facultative mutualism, where the balance between these negative and positive effects of ants on EFN-bearing plants are not well known
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