403 research outputs found

    Longitudinal analysis of viral shedding in astronauts before, during, and after a mission to the International Space Station

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    Trabalho de Projeto de Mestrado, Bioestatística, 2022, Universidade de Lisboa, Faculdade de CiênciasHerpesviruses were measured in 23 astronauts with the objective of understanding their reactivation pattern during a long-duration space mission. The measurements consisted of the number of viral copies of cytomegalovirus (CMV), Epstein-Barr (EBV) and varicella-zoster (VZV) viruses collected at different moments: two before (L−180, L−45 ), three during (Early, Mid, Late) and two after (R+0, R+30 ) a spaceflight. These data present three difficulties: small sample size, zero-inflation and missing responses. The methods used were confidence intervals for proportions, McNemar’s exact test, linear models for categorical data, multiple imputation using chained equations (MICE), and logistic regression mixed models (LRMM). CMV was only measured once during the flight (During). There was significant increase in the reactivation proportion during flight compared to before and after flight measures L−180 and R+30. The LRMM fitted for binary CMV that had moments with reactivation as fixed effects and random effect subject was significant at coefficient R+30 (p=0.043), although During (p=0.078) had a p-value close to the statistical significance of 5%. EBV and VZV were measured in saliva samples and have missing responses for the inflight moments. An increase of the amplitude of reactivation was detected at Late for both viruses. The data seemed to follow a missing-completely-at-random mechanism for both viruses (p=0.490 and 0.070 for EBV and VZV, respectively). Fifty imputed data sets were generated for each virus. For EBV the pooled estimates for the reactivation probability were 0.126, 0.239, 0.454 for Early, Mid, Late, respectively, and for VZV 0.488, 0.330, 0.617, respectively. The pooled LRMM of EBV with L−180 as baseline was significant at L−45 (p=0.029) and Late (p=0.022), and R+0 (p=0.053) was close to significance. For VZV, R+30 was the only significant different from baseline Early(p=0.002). In conclusion, the stress conditions of the spaceflight affected the reactivation dynamics of all three viruses

    Struggles for self-definition of Black subjectivities in organizational contexts: racism, self-image, and aphrodiaspora resistance

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    En este artículo discutimos algunas tensiones entre las modulaciones discursivas antirracistas en contextos organizacionales ante episodios de racismo y las acciones individuales de trabajadores y trabajadoras que involucran la denuncia y la reparación de tales acciones en los tribunales. Analizamos siete casos que tuvieron visibilidad mediática a partir de una búsqueda en las colecciones de Folha de S.Paulo en el período entre 2000 y 2021, y concluimos que hay operaciones discursivas de las categorías conciencia negra occidental (racismo) y conciencia negra del negro (autodefinición) según el concepto de razón negra.This article discusses some tensions between anti-racist discursive modulations in organizational contexts before episodes of racism and individual actions of workers to denounce and redress them in court. To this end, the study investigated seven cases that reached media visibility, selected from a search in the Folha de São Paulo archive (2000-2021), indicating discursive operations in the categories western Black consciousness (racism) and Black consciousness of Black people (self-definition) – according to the concept of Black reason.Neste artigo, discutimos algumas tensões entre modulações discursivas antirracistas em contextos organizacionais em face a episódios de racismo e ações individuais de trabalhadores e trabalhadoras para denunciá-los e repará-los judicialmente. Metodologicamente, analisamos sete casos que tiveram visibilidade midiática a partir de busca no acervo da Folha de S.Paulo entre 2000 e 2021, nos quais verificamos operações discursivas das categorias consciência ocidental do negro (racismo) e consciência negra do negro (autodefinição), de acordo com o conceito de razão negra

    Neinei -- The Neutron Imaging Center at the Brazilian Multipurpose Reactor

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    Neutron imaging is a non-destructive technique for analyzing a wide class of materials, such as archaeological or structures of industrial materials. Technological advances, in recent decades, have had a great impact on the neutron imaging technique, evolving from simple radiographs using films (2D) to modern tomography systems with digital processing (3D). The Instituto de Pesquisas Energ\'eticas e Nucleares (IPEN), in Brazil, houses a 5MW research nuclear reactor, called IEA-R1, where there is a neutron imaging instrument located at the beam hole 08 (BH08) with 1.0×1061.0 \times 10^{6} n/cm2sn/cm^{2}s in the sample position. IEA-R1 is over 60 years old and the future of neutron science in Brazil, including imaging, will be expanded on a new facility called the Brazilian Multipurpose Reactor (RMB). The RMB will house a suite of instruments at the Neutron National Laboratory, including the neutron imaging facility called Neinei. Inspired by recent work, we have calculated the thermal neutron flux at the sample position, using the Monte Carlo method, in the Neinei and compared it to the results obtained with the Neutra (PSI), Antares (FRM II), BT2 (NIST) and DINGO (OPAL) instruments. The results are promising and provide avenues for future improvements.Comment: 8 pages, 9 figures. Preprin

    Yin Yang Convolutional Nets: Image Manifold Extraction by the Analysis of Opposites

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    Computer vision in general presented several advances such as training optimizations, new architectures (pure attention, efficient block, vision language models, generative models, among others). This have improved performance in several tasks such as classification, and others. However, the majority of these models focus on modifications that are taking distance from realistic neuroscientific approaches related to the brain. In this work, we adopt a more bio-inspired approach and present the Yin Yang Convolutional Network, an architecture that extracts visual manifold, its blocks are intended to separate analysis of colors and forms at its initial layers, simulating occipital lobe's operations. Our results shows that our architecture provides State-of-the-Art efficiency among low parameter architectures in the dataset CIFAR-10. Our first model reached 93.32\% test accuracy, 0.8\% more than the older SOTA in this category, while having 150k less parameters (726k in total). Our second model uses 52k parameters, losing only 3.86\% test accuracy. We also performed an analysis on ImageNet, where we reached 66.49\% validation accuracy with 1.6M parameters. We make the code publicly available at: https://github.com/NoSavedDATA/YinYang_CNN.Comment: 12 pages, 5 tables and 6 figure

    Fake news, discursos de ódio e ativismo digital: movimentos sociais de desmonetização, desafios jurídicos e reflexões sobre o case sleeping giants Brasil

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    A falta de regulamentação dos serviços de anúncios na internet causa incertezas para a sociedade, mas esta omissão não desencorajou cidadãos, que, pelo ativismo social (digital), encontraram alternativas para enfrentar as consequências do problema. Neste contexto, este artigo objetiva investigar as repercussões jurídicas, políticas e sociais do movimento de ativismo digital Sleeping Giants Brasil, que surgiu em 2020 com a proposta de combater e desmonetizar portais que produzem e divulgam notícias falsas (fake news) e discursos de ódio, especialmente quanto a legitimidade de sua atuação. Busca-se então responder o seguinte: quais os limites e (im)possibilidades para se falar em legitimidade do movimento Sleeping Giants no Brasil, ante a ausência de normas regulamentadoras, da judicialização ocorrida e do contexto sociológico do país? Metodologicamente adota-se como teoria de base autores que abordam tais perspectivas, envoltas entre direito, comunicação e política, como Castells, Bucci, Empoli e Sarlet. Ainda, emprega-se a abordagem sistêmico-complexa, aliada ao método de procedimento monográfico e a técnica de pesquisa bibliográfica. Ao final o estudo permite concluir que até o suprimento das lacunas legislativas, o Poder Judiciário restará incumbido de valorar os direitos fundamentais em cada caso. Ademais, sem políticas públicas que empoderem os cidadãos, proporcionando-lhes o controle social da legitimidade de Movimentos populares, serão os juízes que decidirão se iniciativas como o Sleeping Giants Brasil são legitimas ou não. Outrossim, ressalta-se que esta pesquisa é original e relevante para o campo jurídico, especialmente pela atualidade dessas problemáticas e o necessário aprofundamento do debate sobre o legítimo enfrentamento da desinformação

    Análise da Composição Cianobacteriana das Esteiras Pustulares em Salina, Araruama, Rio de Janeiro.

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    Julieta saline receives water from lagoa de Araruama, which is located in the state of Rio de Janeiro, to the East of the city of Araruama and to the west of the city of Cabo Frio, between 22o 49’ and 22o 57’ S latitude and 42o 00’ and 42o 23’ W longitude. It is composed by a series of soil tanks obtained by natural excavation, where water gradually concentrates through natural evaporation until salt precipitation. The reservoirs can be divided in three types, according to their activity: cargo, evaporator and crystallizer tanks. The process of making such reservoirs waterproof is enabled bya fine layer of algae which is formed naturally with the passing of time. This study is based on monthly collects within the period ranging from May, 2004 to October, 2004, along three collection stations set up in different saline reservoirs. To identify the microbic composition, fresh, semi-permanent and permanent laminae were obtained and their analysis were performed by means of optical microscopy. The analysis revealed a total of twenty cyanobacterial types. In all layers, a predominant amount of oval spherical forms was observed. The predominance of cyanobacteria is justified by the fact that they are carriers of high morphological adaptations which enables them to survive in various types of environments andbe predominant in hypersaline sites

    EXTRAÇÃO AUTOMÁTICA DAS REDES DE DRENAGEM NO PANTANAL DE AQUIDAUANA: ESTUDO COMPARATIVO COM DADOS SRTM, ASTER E CARTA TOPOGRÁFICA DSG

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    Este estudo averigua a conformidade entre drenagens extraídas automaticamente a partir de MDE’s produtos SRTM das fontes USGS, EMPRAPA e TOPODATA, produto ASTER e drenagem definida na carta topográfica de Aquidauana. Para análises de cunho quantitativo e qualitativo foram realizados procedimentos de intersecção, sobreposição, obtenção de dados de densidade e análises estatísticas. Os resultados indicam baixa concordância entre as redes de drenagem obtidas, tanto na relação entre os produtos dos MDE’s, como a relação destes com as linhas de drenagem presentes na carta topográfica. Palavras-chave: Modelo digital de elevação. Rede de drenagem. Topografia. ASTER-MDE. SRTM. Automatic extraction of drainage networks in the Aquidauana Pantanal: a comparative study using SRTM, ASTER and DSG topographical chart This work aims to investigate the correspondence between automatically extract drainages from SRTM-DEM products from different sources (USGS, EMBRAPA and TOPODATA), ASTER-DEM product and the mapped drainage on Aquidauana topographic chart. For the quantitative and qualitative analysis we performed the following routines: intersection, overlap, vector density calculation and statistical procedures. Our results indicate very low agreement between the drainages networks extract from all sources, particularly from the vectors mapped on topographic chart with the DEM’s. Key words: Digital elevation model. Drainage network. Topography. ASTER-DEM. SRTM

    Turismofobia e os impactos econômicos do turismo nos discursos midiáticos do jornal “El País”

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    Tendo o espaço urbano como locus para sua concepção e seu desenvolvimento, o turismo gera diferentes formas de apropriação e de relacionamento com os lugares em que ocorre. Os impactos da atividade, tradicionalmente discutidos no âmbito acadêmico, gradativamente ganham eco em uma variedade de plataformas comunicacionais, em virtude da dimensão atribuída ao turismo por diversos grupos sociais. Os discursos midiáticos reproduzidos em jornais, na televisão e no cinema criam e reforçam sentidos ligados ao modo como se interpreta o fenômeno turístico, e nessa esfera ganham espaço termos e expressões com forte carga de significados, como a turismofobia. Partindo desse cenário, este trabalho tem como objetivo discutir as representações midiáticas do termo “turismofobia” nos discursos sobre os impactos econômicos do turismo identificados a partir de publicações do jornal espanhol El País, no período entre julho e agosto de 2017. A fim de explorar o conteúdo de cada publicação, foi realizada a análise da construção de tais conteúdos realizados pelos jornalistas, comparando-se os dados com o escopo conceitual da pesquisa. Os resultados estudados permitiram observar que o El País tem sido um espaço de destaque na criação de sentidos ligados à turismofobia como forma de manifestar, discursivamente, conflitos e contradições gerados a partir dos impactos econômicos do turismo na Espanha
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