3,802 research outputs found

    A construção do pensamento complexo num grupo de pesquisa em educação: primeiros passos

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    O presente trabalho busca analisar a constituição e dinâmica de dois grupos de pesquisa da UFSCar/CNPq- “Formação de Professores, Ambientalização Curricular e Educação em Ciências” e “Grupo de Estudo e Pesquisa em Educação Científica” - à luz da teoria dos grupos operativos de Pichon-Rivière e da teoria da complexidade. Para isso foram realizadas análises qualitativas das gravações em áudio dos encontros dos grupos e dos resumos das atividades dos mesmos. A partir das análises observaram- se aproximações entre a dinâmica do grupo de pesquisa com algumas características específicasdos grupos operativos na perspectiva Pichoniana. Na relação com o paradigma da complexidade, a principal dificuldade do grupo foi o rompimento com paradigmas anteriores, porém também pode-se observar aproximações e avanços do grupo com a construção do pensamento complexo

    Plagioscion squamosissimus (Sciaenidae) and Parachromis managuensis (Cichlidae): A Threat to Native Fishes of the Doce River in Minas Gerais, Brazil

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    The middle section of the lake basin of the Doce River in Minas Gerais State, Brazil is plagued by grave environmental problems, including the introduction of non-native fish, which reduces the biodiversity of this region. This study reports the presence of two newly-detected non-native species in the Doce River Basin. Sampling efforts included gill nets with mesh size of 3 to 12 mm (measured diagonally) and trawling nets, both of which were used in independent field campaigns in 2002 and 2011. The two new invasive Perciform fishes, Plagioscion squamosissimus (Heckel 1840) and Parachromis managuensis (Günther 1867) were collected in Caratinga and Rio Doce municipalities. These records and other reports on non-native fishes suggest favorable environmental conditions for the establishment of invasive species in this drainage. These invasive species have behavior and diet observed in other wide distribution exotic fish of Rio Doce Basin representing a threat to the 77 native fishes of this region, 37 of which are endangered

    A major QTL corresponding to the Rk locus for resistance to root-knot nematodes in cowpea (Vigna unguiculata L. Walp.).

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    Key messageGenome resolution of a major QTL associated with the Rk locus in cowpea for resistance to root-knot nematodes has significance for plant breeding programs and R gene characterization. Cowpea (Vigna unguiculata L. Walp.) is a susceptible host of root-knot nematodes (Meloidogyne spp.) (RKN), major plant-parasitic pests in global agriculture. To date, breeding for host resistance in cowpea has relied on phenotypic selection which requires time-consuming and expensive controlled infection assays. To facilitate marker-based selection, we aimed to identify and map quantitative trait loci (QTL) conferring the resistance trait. One recombinant inbred line (RIL) and two F2:3 populations, each derived from a cross between a susceptible and a resistant parent, were genotyped with genome-wide single nucleotide polymorphism (SNP) markers. The populations were screened in the field for root-galling symptoms and/or under growth-chamber conditions for nematode reproduction levels using M. incognita and M. javanica biotypes. One major QTL was mapped consistently on linkage group VuLG11 of each population. By genotyping additional cowpea lines and near-isogenic lines derived from conventional backcrossing, we confirmed that the detected QTL co-localized with the genome region associated with the Rk locus for RKN resistance that has been used in conventional breeding for many decades. This chromosomal location defined with flanking markers will be a valuable target in marker-assisted breeding and for positional cloning of genes controlling RKN resistance

    Desenvolvimento de um dispositivo de administração de insulina para crianças diabéticas

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    Este projeto visou o desenvolvimento de um dispositivo deadministração de insulina para crianças diabéticas que permitisse aumentar aqualidade de vida do doente através de um produto discreto e inovador. Assim,foi estudado o histórico da doença, identificado os dispositivos existentes nomercado, levantadas as novas tecnologias no tratamento da doença e asnecessidades do utilizador. O fator motivador para o desenvolvimento desteprojeto foi dado pela inexistência de um dispositivo de administração de insulinaexclusivo para crianças e adolescentes diabéticos. O conceito do dispositivo foibaseado em uma órtese umbilical, tornando o dispositivo imperceptível no corpodo diabético em sua vida diária. Além disso, aplicação tecnológica do dispositivopermite a conexão dos dados referentes a administração de insulina viabluetooth com medidores de glicemia, telemóveis, smartphones e tablets

    Optimization of the Anodization Processing for Aluminum Oxide Gate Dielectrics in ZnO Thin Film Transistors by Multivariate Analysis

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    The present study reports a two-level multivariate analysis to optimize the production of anodized aluminum oxide (Al<sub>2</sub>O<sub>3</sub>) dielectric films for zinc oxide thin-film transistors (TFTs). Fourteen performance parameters were measured and analysis of variance (ANOVA) of the combined responses has been applied to identify how the Al<sub>2</sub>O<sub>3</sub> dielectric fabrication process influences the electrical properties of the TFTs. Using this approach, the levels for the manufacturing factors to achieve optimal overall device performance have been identified and ranked. The cross-checked analysis of the TFT performance parameters demonstrated that the appropriate control of the anodization process can have a higher impact on TFT performance than the use of traditional methods of surface treatment of the dielectric layer. Flexible electronics applications are expected to grow substantially over the next 10 years. Given the complexity and challenges of new flexible electronics components, this “multivariate” approach could be adopted more widely by the industry to improve the reliability and performance of such devices

    Efeitos de mudanças regulatórias no microcrédito no desempenho nanceiro e social de cooperativas de crédito brasileiras

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    This study investigates whether the performance of credit unions that offer microcredit in Brazil was affected by the advent of Crescer – the National Microcredit Program. This research fills a gap in the literature because few papers investigate credit unions that work with microcredit and also the effects of governmental interventions related to microcredit operations. Studies of this type may help evaluate the impact of governmental interventions on the performance of the institutions that are directly or indirectly affected. Our results add to the debate about microcredit and about the inclusion of credit unions in this market. In particular, our evidence may influence the design of public policies and the strategies of microfinance institutions, which typically combine economic and social objectives. Based on the literature, we calculate fifteen indicators for each credit union, related to their financial and social performance. The inferences are based on the implementation of the difference in differences estimator using the advent of Crescer, in 2011, as the exogenous event of interest and including in the control group the credit unions that did not provide microcredit loans throughout the sample period. This research presents evidence that the volume of clients and microcredit operations performed by Brazilian credit unions was positively affected by regulatory changes that took place in 2011, consistently with the objectives of the governmental intervention. The evidence also suggests that the governmental intervention did not harm the financial sustainability of the credit unions. The main changes are: a substantial reduction of interest rates and transaction costs, the implementation of subsidies to participants in the program, and a push for public banks to enhance their supply of productive and oriented microcredit.Este estudo investiga se e como o desempenho nanceiro e social das cooperativas que ofertam microcrédito no Brasil foi afetado pelo advento do Crescer – Programa Nacional de Microcrédito. A pesquisa preenche lacuna na literatura da área, uma vez que há poucos estudos sobre cooperativas que trabalham com microcrédito e também sobre os efeitos de intervenções governamentais na área de microcrédito. Pesquisas como esta podem auxiliar na avaliação do impacto de intervenções governamentais sobre o desempenho das instituições direta ou indiretamente afetadas. Os resultados do estudo acrescentam novos elementos ao debate sobre o mercado do microcrédito e sobre a inserção das cooperativas de crédito nesse mercado. Em particular, as evidências aqui discutidas oferecem subsídio para o desenho de políticas públicas e para a de nição de estratégias de instituições de micro nanças, as quais tipicamente combinam objetivos econômicos e sociais. Com base na literatura, foram calculados 15 indicadores para cada cooperativa, relacionados ao seu desempenho nanceiro e social. As inferências baseiam-se na implementação do estimador de diferença em diferenças utilizando o advento do Crescer, em 2011, como o evento exógeno de interesse, e incluindo, no grupo de controle, as cooperativas de crédito que não forneceram empréstimos de microcrédito ao longo do período amostral. A pesquisa apresenta evidências de que o volume de clientes e de operações de microcrédito realizadas pelas cooperativas de crédito brasileiras foi positivamente afetado por mudanças regulatórias ocorridas em 2011, de forma compatível com os objetivos da intervenção governamental. As evidências também sugerem que a intervenção governamental enfocada não comprometeu a sustentabilidade nanceira das cooperativas. As mudanças enfocadas são: redução substancial das taxas de juros e custos de transação, implementação de subsídios aos participantes do programa e impulso para bancos públicos para aumentar sua oferta de microcrédito produtivo e orientado

    Spin-phase-space-entropy production

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    Quantifying the degree of irreversibility of an open system dynamics represents a problem of both fundamental and applied relevance. Even though a well-known framework exists for thermal baths, the results give diverging results in the limit of zero temperature and are also not readily extended to nonequilibrium reservoirs, such as dephasing baths. Aimed at filling this gap, in this paper we introduce a phase-space-entropy production framework for quantifying the irreversibility of spin systems undergoing Lindblad dynamics. The theory is based on the spin Husimi-Q function and its corresponding phase-space entropy, known as Wehrl entropy. Unlike the von Neumann entropy production rate, we show that in our framework, the Wehrl entropy roduction rate remains valid at any temperature and is also readily extended to arbitrary nonequilibrium baths. As an application, we discuss the irreversibility associated with the interaction of a two-level system with a single-photon pulse, a problem which cannot be treated using the conventional approach.Comment: 12 pages, 16 figure
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