Dimensional reduction of the CPT-even electromagnetic sector of the Standard Model Extension

The CPT-even abelian gauge sector of the Standard Model Extension is represented by the Maxwell term supplemented by $(K_{F})_{\mu\nu\rho\sigma}F^{\mu\nu}F^{\rho\sigma}$, where the Lorentz-violating background tensor, $(K_{F})_{\mu\nu\rho\sigma}$, possesses the symmetries of the Riemann tensor. In the present work, we examine the planar version of this theory, obtained by means of a typical dimensional reduction procedure to $(1+2)$ dimensions. The resulting planar electrodynamics is composed of a gauge sector containing six Lorentz-violating coefficients, a scalar field endowed with a noncanonical kinetic term, and a coupling term that links the scalar and gauge sectors. The dispersion relation is exactly determined, revealing that the six parameters related to the pure electromagnetic sector do not yield birefringence at any order. In this model, the birefringence may appear only as a second order effect associated with the coupling tensor linking the gauge and scalar sectors.The equations of motion are written and solved in the stationary regime. The Lorentz-violating parameters do not alter the asymptotic behavior of the fields but induce an angular dependence not observed in the Maxwell planar theory.Comment: 13 pages, revtex style, no figures, to appear in Physical Review D(2011

Um ajuste justo ou mais alguns passos atrás para a educação básica pública no Brasil? SEÇÃO

Neste artigo, iremos apresentar e discutir o relatório Um ajuste justo: análise da eficiência e equidade do gasto público no Brasil (2017), produzido pelo Banco Mundial para conjecturar acerca da necessidade de um ajuste fiscal radical para sanar as finanças e os problemas orçamentários do país. O relatório em questão apresenta alguns argumentos e estratégias para a execução de um ajuste das contas públicas, em especial, para setores como saúde, educação, previdência social, dentre outros. Partindo de uma abordagem crítica acerca das recomendações do Banco para a educação básica pública brasileira, questionamos as diretrizes expressas no documento, que apontam para a necessidade de contingenciamentos e cortes no orçamento como forma de melhorar as contas e equilibrar a razão investimento/resultados. O relatório ampara-se em uma econometria que busca legitimar a todo custo a tese que vê na política fiscal contracionista o melhor caminho para intervir na educação básica pública. Ao longo do texto, discutimos se isso é factível considerando o nosso contexto histórico de subfinanciamento, onde, diferentemente de outros países mais ricos e menos desiguais, jamais alcançamos um patamar de investimentos suficientes para garantir o acesso, a permanência e a qualidade na educação básica.This article aims to present and discuss the report A Fair Adjustment: Efficiency and Equity of Public Spending in Brazil (2017) produced by The World Bank, in order to analyze the need for a radical fiscal adjustment aimed to solve the financial and budgetary issues of the country. The report under study presents some arguments and strategies for the implementation of a public spending adjustment, especially for sectors such as health, education, social security, and others. Through a critical approach in relation to the recommendations of the Bank directed at the Brazilian public basic education, the guidelines expressed in the document were questioned. These guidelines point to the need of budgetary contingencies and cutting as methods of improving public accounts and of balancing the investment/returns ratio. The report is grounded on an econometrics that seeks to legitimate, at all costs, the thesis that regards the contractionist fiscal policy as the best path to intervene in public basic education. Throughout the text, a discussion about the feasibility of such a policy will be presented, taking into consideration our historical context of underfunding, in which, unlike other countries that are richer and less unequal, Brazil has never reached the necessary investment level to guarantee access, permanence and quality for people in basic education

Sobre a avaliação do conhecimento gramatical escolar : um estudo dos exames nacionais de português de 2009

Se aceitamos que “a avaliação é sinónimo de sucesso” (Pacheco & Zabalza, 1995: 7), ao estudar a problemática da avaliação e entendendo a avaliação oficial como um factor constitutivo da disciplina de Português, discutiremos como são representados e avaliados os conhecimentos explícitos sobre a língua materna. Assim, na sequência de um outro trabalho sobre a avaliação gramatical (Silva, no prelo), pretendemos, com o presente artigo, continuar o estudo do domínio da gramática em provas de avaliação externa, identificando o conhecimento gramatical oficialmente avaliado. Neste sentido, o objectivo principal deste texto é o de caracterizar a configuração do conhecimento gramatical nos exames nacionais de Português realizados em 2009. Para debater tais questões, este trabalho desenvolve-se em duas partes: a) apresentação das dimensões do estudo das provas de avaliação externa de Português; b) discussão e análise dos dados, com a apresentação dos primeiros resultados do estudo das provas de avaliação de Português realizadas em 2009. As conclusões de um trabalho desta natureza deverão apontar no sentido de uma melhor compreensão do papel da regulação externa dos saberes relativos ao conhecimento explícito da língua, ao mesmo tempo que nos permitirão determinar as novas formas de configuração da gramática escolar portuguesa

Exploiting the Use of Convolutional Neural Networks for Localization in Indoor Environments

Indoor localization has been an active research area for the last two decades. A great number of sensors have been applied in the task of localization—some with high computational and energy demands (e.g. laser beams), or with issues related to the coverage area, for example, by making use of images obtained by a network of cameras. A different approach, which presents less energy demands and a wide area of coverage, can be created by means of the signal strength of wireless networks. The open issue with signal strength is its high instability due to interferences, attenuation and fading, which, in general, makes the localization systems to present less than desired accuracy. In this article, we exploit the use of Convolutional Neural Networks (ConvNets) in the task of localization. The main motivation behind the employment of ConvNets is its inherent ability of feature extraction, which we believe can deal better with the noise without a filtering step. We evaluate how ConvNets can be employed and identify the best topologies that lead to the lowest errors

Statistics education from the perspective of statistical literacy: Reflections taken from studies with teachers

The aim of this article is to discuss aspects of statistical literacy from research on statistics education conducted with teachers and developed by the Research Group on Mathematics and Statistics Education (GPEME) at the Universidade Federal de Pernambuco (UFPE). These investigations were influenced by international discussions on a perspective of statistical literacy that focuses not only on knowledge and technical procedures of curriculum content in statistics, but also on developing critical attitudes towards approaching data. The reflections are based on the analysis of research with teachers of different levels and teaching modalities, who engaged in problem-solving activities associated with various topics in statistics. The article problematizes the challenges of addressing statistical literacy in the initial and continuing education of teachers who learn and teach statistics. Discussions are included on research that has methodologically addressed teacher participation in groups that involve cooperative and collaborative processes and that associate teacher education with this broader perspective of statistical literacy. The research presented offers empirical evidence that an effective pedagogic strategy to improve teachers’ knowledge of statistics is to explore of dialogic situations in which they may be led to reflect on their own interpretations of statistical data related to contemporary contexts that involve different themes. Reflections on the research results also indicate some possible pedagogic implications and the need for future research that may better develop the topics studied

Bloqueio da liquidez e estabilização : o fracasso do Plano Collor

Orientador: Jose Carlos de Souza BragaTese (doutorado) - Universidade Estadual de Campinas, Instituto de EconomiaResumo: Não informadoAbstract: Not informed.DoutoradoDoutor em Economi

Science-based solutions to foster connectivity of wolf populations are limited by available data

European wolf populations are currently exposed to distinct sources of anthropogenic disturbance and mortality that can cause dispersal limitations and lead to isolation. The identification of factors that act as complete or partial barriers to movement, dispersal, or gene flow contribute to foster connectivity between populations. We reviewed the existing literature (N=32) on wolf population barriers to 1) identify main barriers to connectivity; 2) outline different methodologies; and 3) highlight knowledge gaps. Based on the reviewed studies that empirically tested barrier occurrence (N=14), we compiled data on wolf population structure, anthropogenic disturbance, land cover, ecological factors, geographical features, and prey availability, and tested them as predictors to explain barrier occurrence at continental scale. We report few studies directly addressing this subject for one of the most emblematic and thoroughly studied species, inhabiting one of the most modified landscapes in the world. Albeit our analysis suggested that anthropogenic features are the main drivers of barrier occurrence, we highlight that the absence of standardised data limits our understanding of this subject. Long-term, intensive monitoring programs, explicit hypothesis-driven research using empirical methodologies, and the integration of information on databases for collaborative science are needed to increase the conservation and management relevance of future scientific outcomes on this topic.info:eu-repo/semantics/publishedVersio

Diet of Boana albopunctata (Anura: Hylidae) in an Atlantic Forest fragment of southeastern Brazil

Anuros são importantes na cadeia trófica por se alimentarem de invertebrados, muitos dos quais são prejudiciais aos humanos. Nós investigamos a dieta de 100 espécimes de Boana albopunctata provenientes do município de Ponte Nova, Estado de Minas Gerais, em um fragmento da Mata Atlântica e obtivemos 107 presas, sendo as mais representativas Lepidoptera, Araneae e Coleoptera. A espécie tendeu a selecionar maiores presas em menores quantidades, assim como registrado em outros trabalhos, mas diferiu em táxons encontrados, devido à variação espacial e temporal de micro habitats das paisagens de CerradoAnurans are important in trophic food chains because they feed on invertebrates, many of which are harmful to humans. We investigated the diet of 100 specimens of Boana albopunctata from an Atlantic Forest fragment in Ponte Nova municipality, Minas Gerais state. We obtained 107 prey items. The most common prey were Lepidoptera, Araneae and Coleoptera. This species tended to select larger prey in smaller quantities as found in previous reports, but differed in the taxons selected because of spatial and temporal variation in microhabitats and the availability of invertebrates in savanna

Acetilcisteína em retalho cutâneo randômico em ratos

PURPOSE: Analyze the ability of Acetylcysteine to reduce distal necrosis in a random skin flap, in the rat. METHODS: The present study utilized 28 adult male Wistar-EPM rats distributed, at random, in two groups of 14 animals. Control group rats (CG) received distilled water and Acetylcysteine group animals (NACG) received NAC (300 mg/kg) by oral infusion, 15 minutes before flap elevation. On the seventh postoperative day, percentage of distal necrosis was determined and skin samples collected in order to allow determination of MDA levels. RESULTS: The mean necrotic area in CG group (control) was 66 % and in NACG group (Acetylcysteine) 52 %, a statistically significant difference according to the Mann-Whitney test (U calc = 25; U crit = 45). MDA levels were lower in the CG flap skin samples than in the NACG samples (U calc = 24; U crit = 45), the oposite being true in the normal skin samples (U calc = 10; U crit = 45). CONCLUSION: Acetylcysteine was effective, according to the model used, reducing the percentage of distal necrosis in NACG rats.OBJETIVO: Analisar a capacidade da Acetilcisteína em reduzir a necrose distal em um retalho cutâneo randômico, no rato. MÉTODO: O presente trabalho utilizou 28 ratos machos adultos Wistar-EPM divididos, ao acaso, em dois grupos de 14 animais. Os ratos do grupo controle (CG) receberam água destilada e os animais do grupo Acetilcisteína (NACG) receberam NAC (300 mg/kg) por infusão oral, 15 minutos antes da elevação do retalho. No sétimo dia de pós-operatório, a porcentagem de necrose distal foi determinada e amostras de pele colhidas para permitir a determinação dos níveis de MDA. RESULTADOS: A área média de necrose no grupo CG (controle) foi 66 % e no grupo NACG (Acetilcisteína) 52 %, uma diferença estatisticamente significante de acordo com o teste de Mann-Whitney (U calc = 25; U crit = 45). Os níveis de MDA foram menores nas amostras de pele do retalho no grupo CG do que nas amostras do grupo NACG (U calc = 24; U crit = 45), o oposto sendo verdadeiro nas amostras de pele normal (U calc = 10; U crit = 45). CONCLUSÃO: A Acetilcisteína foi eficaz, de acordo com o modelo usado, reduzindo a porcentagem de necrose distal nos ratos NACG.UNIFESP Plastic Surgery DivisionUNIFESPUNIFESP, Plastic Surgery DivisionUNIFESPSciEL

An overview of the research and patenting activities that took place in Brazil during the 2010s

A National Innovation System is an interconnected network of public and private institutions that aims at the development and diffusion of new technologies. We use the Derwent Innovations platform to study the patent applications in Brazil between 2010 and 2020, and to identify the main technological areas that have benefited from the research conducted in the country. Our main methodological contribution is to present indicators that measure the technological importance and international scope of Brazilian patents. The results show that private companies rarely resort to intellectual property protection mechanisms and that public universities are responsible for most patent applications. This study concludes that private companies innovate little, and, as a result, academic research tends to act as a substitute for business investments in research and development, especially in software development, pharmaceutical outputs, and scientific instrumentation. On the other hand, Brazilian universities and companies are both being excluded from the global race for the Internet of Things patents that has characterized the fourth industrial revolution