2,583 research outputs found

    Biologia reprodutiva de Madracis decactis (Lyman, 1859) (Cnidaria, Scleractinia) de recifes do sul da Bahia, Brasil

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    The reproductive biology of the scleractinian coral Madracis decactis (Lyman, 1859) was studied in southern Bahia reefs, the most extensive and richest reef areas of the South Atlantic. Madracis decactis is one of the most widespread zooxanthellate corals in Brazil and can be found at the edges of the reefs on exposed or cryptic areas. The objective of this study was to investigate patterns of the sexual reproduction of M. decactis. Information about sexuality, gonad arrangement, mode of development, gametogenesis and temporal patterns of the reproductive cycle were obtained using histological procedures. The results showed that M. decactis is a hermaphroditic species and probably presents a brooding mode of development in southern Bahia reefs. Reproductive cycle is annual and lasts about four months. Female and male gametes started to develop at different times, with spermaries appearing in approximately the second month of oogenesis and lasting about two months. Gametogenesis started on the summer onset (December) and was complete at early autumn (April). Mature gametes were not present in samples collected between the end of March and April. Evidences suggested that fecundation, embryogenesis and the possible planulae release occurred within this period, of approximately one month.A biologia reprodutiva do coral escleractíneo Madracis decactis (Lyman, 1859) foi estudada nos recifes do sul da Bahia, a mais extensa e rica área recifal do Atlântico Sul. Madracis decactis é um dos corais zooxantelados mais amplamente distribuídos do Brasil, podendo ser encontrado nas bordas dos recifes em locais expostos ou abrigados. O objetivo deste estudo foi investigar padrões na reprodução sexual de M. decactis. Informações sobre sexualidade, arranjo das gônadas, modo de desenvolvimento, gametogênese e padrões temporais do ciclo reprodutivo foram obtidas através de procedimentos histológicos. Os resultados mostraram que M. decactis de recifes do sul da Bahia é uma espécie hermafrodita e provavelmente incubadora de larvas. O ciclo reprodutivo é anual e dura cerca de quatro meses. Gametas masculinos e femininos começaram seu desenvolvimento em momentos diferentes, com cistos espermáticos aparecendo aproximadamente no segundo mês da ovogênese e durando cerca de dois meses. A gametogênese se iniciou no começo do verão (dezembro) e completou-se no princípio do outono (abril). Não foram observados gametas maduros nas amostras coletadas entre o final de março e abril. Evidências sugeriram que a fecundação, a embriogênese e a possível liberação de plânulas ocorreram dentro desse período, com duração de cerca de um mês

    ERK-1 MAP kinase prevents TNF-induced apoptosis through bad phosphorylation and inhibition of bax translocation in HeLa cells

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    Extracellular signal-regulated kinase (ERK) 1/2 signaling is involved in tumor cell survival through the regulation of Bcl-2 family members. To explore this further and to demonstrate the central role of the mitochondria in the ERK1/2 pathway we used the HeLa cellular model where apoptosis was induced by tumor necrosis factor (TNF) and cycloheximide (CHX). We show that HeLa cells overexpressing ERK-1 displayed resistance to TNF and CHX. HeLa cells overexpressing a kinase-deficient form of ERK-1 (K71R) were more sensitive to TNF and CHX. In the ERK-1 cells, Bad was phosphorylated during TNF + CHX treatment. In the HeLa wt cells and in the K71R clones TNF and CHX decreased Bad phosphorylation. ERK-1 cells treated with TNF and CHX did not release cytochrome c from the mitochondria. By contrast, HeLa wt and K71R clones released cytochrome c. Bax did not translocate to the mitochondria in ERK-1 cells treated with TNF + CHX. Conversely, HeLa wt and K71R clones accumulated Bax in the mitochondria. In the HeLa wt cells and in both ERK-1 transfectants Bid was cleaved and accumulated in the mitochondria. The caspase-8 inhibitor IETD-FMK and the mitochondrial membrane permeabilization inhibitor bongkrekic acid (BK), partially prevented cell death by TNF + CHX. Anisomycin, a c-Jun N-terminal kinases activator, increased TNF-killing. The ERK-1 cells were resistant to TNF and anisomycin, whereas K71R clones resulted more sensitive. Our study demonstrates that in HeLa cells the ERK-1 kinase prevents TNF + CHX apoptosis by regulating the intrinsic mitochondrial pathway through different mechanisms. Inhibition of the intrinsic pathway is sufficient to almost completely prevent cell death. © 2009 Wiley-Liss, Inc

    Turismo e ativação popular do patrimônio-territorial no Centro Histórico de Planaltina – DF

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    Trabalho de Conclusão de Curso (graduação)—Universidade de Brasília, Centro de Excelência em Turismo, 2020.Algumas cidades do Distrito Federal passam por uma “negação” histórica e o descaso com sua cultura, diante da Brasília utópica e moderna. Planaltina é a primeira cidade do Planalto Central, rica de história e representatividade. A cidade passa pelo processo de presença marcante do povo e a ausência do governo. O objetivo deste trabalho é levantar e analisar o patrimônio material e imaterial do centro histórico de Planaltina - DF, para verificar uma possível ativação popular de um patrimônio-territorial, a partir dos sujeitos viventes na cidade. O trabalho se estrutura, primeiramente, na formação territorial de Planaltina, frente a Brasília modernista. Na sequência, debate os conceitos de patrimônio-territorial e preservação sinérgica e, por fim, cartografa os bens materiais e imateriais do centro histórico, que foram identificados como patrimônio-territorial, em síntese conclui-se construindo a ideia de turismo como uma prática integradora de preservação do patrimônio existente na cidade a partir dos sujeitos situados.Some cities in the Federal District are experiencing a historic “denial” and disregard for their culture, in the face of utopian and modern Brasilia. Planaltina is the first city in the Central Plateau, rich in history and representation. The city goes through the process of marked presence of the people and the absence of the government. The objective of this work is to survey and analyze the material and immaterial heritage of the historic center of Planaltina - DF, to verify a possible popular activation of a territorial heritage, based on the subjects living in the city. The work is structured, primarily, in the territorial formation of Planaltina, in front of modernist Brasilia. Then, it debates the concepts of territorial-heritage and synergistic preservation and, finally, maps the material and immaterial assets of the historic center, which were identified as territorial-heritage and, finally, concludes by constructing the idea of tourism as a integrative practice of preserving the existing heritage in the city from the subjects located

    PIBID e a formação inicial: um novo perfil para a formação do professor

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    Anais do II Seminário Seminário Estadual PIBID do Paraná: tecendo saberes / organizado por Dulcyene Maria Ribeiro e Catarina Costa Fernandes — Foz do Iguaçu: Unioeste; Unila, 2014Este artigo destaca a importância que o Programa Institucional de Bolsa de Iniciação à Docência (Pibid) proporciona aos estudantes dos cursos de licenciatura junto às escolas de educação básica, em um coletivo de ações para a melhoria da formação inicial dos futuros professores. Ainda mostra a ampla influência e abrangência do projeto, pois mobiliza estudantes dos cursos de licenciatura e da educação básica, bem como professores que atuam nestas escolas, pois estes enquanto supervisores, se aproximam novamente da universidade potencializando o projeto e enriquecendo sua práxis pedagógica. Nesse sentido, o programa admite a importância de se construir ações conjuntas para melhoria da formação inicial e continuada de professores estimulando diferentes sujeitos e espaços, sendo que escola de educação básica ocupa um lugar privilegiado para a atuação dos futuros professore

    Multisensory 3D saliency for artficial attention systems

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    In this paper we present proof-of-concept for a novel solution consisting of a short-term 3D memory for artificial attention systems, loosely inspired in perceptual processes believed to be implemented in the human brain. Our solution supports the implementation of multisensory perception and stimulus-driven processes of attention. For this purpose, it provides (1) knowledge persistence with temporal coherence tackling potential salient regions outside the field of view, via a panoramic, log-spherical inference grid; (2) prediction, by using estimates of local 3D velocity to anticipate the effect of scene dynamics; (3) spatial correspondence between volumetric cells potentially occupied by proto-objects and their corresponding multisensory saliency scores. Visual and auditory signals are processed to extract features that are then filtered by a proto-object segmentation module that employs colour and depth as discriminatory traits. We consider as features, apart from the commonly used colour and intensity contrast, colour bias, the presence of faces, scene dynamics and also loud auditory sources. Combining conspicuity maps derived from these features we obtain a 2D saliency map, which is then processed using the probability of occupancy in the scene to construct the final 3D saliency map as an additional layer of the Bayesian Volumetric Map (BVM) inference grid

    Partnering for greater success: local stakeholders and research in tropical biology.

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    Local communities are important stakeholders in resource management and conservation efforts, particularly in the developing world. Although evidence is mixed in suggesting that these resident stakeholders are optimal forest stewards, it is highly unlikely that large tracts of tropical forests will be conserved without engaging local people who depend on them daily for their livelihoods. Stakeholders, who reside in biodiverse ecosystems like tropical forests, are the largest direct users and ultimate decision-makers of forest fate, can be important investors in conservation, harbor local ecological knowledge that complements Western science and frequently have long-term legitimate claims on lands where they reside. Research partnerships with local stakeholders can increase research relevance, enhance knowledge exchange and result in greater conservation success. Different phases of the research cycle present distinct opportunities for partnership, with flexibility in timing, approaches and strategies depending on researcher and local stakeholder needs and interests. Despite being the last step in the research process, dissemination of results can be the best starting point for researchers interested in experimenting with local stakeholder engagement. Still, tropical biologists might not choose to partner with local people because of lack of institutional rewards, insufficient training in stakeholder engagement, insecure research infrastructure in community settings, and time and funding limitations. Although not appropriate in all cases and despite significant challenges, some biological scientists and research institutions have successfully engaged local stakeholders in the research process, proving mutually beneficial for investigators and local people alike and resulting in important innovations in tropical biology and conservation

    Guest Editorial: Non-Euclidean Machine Learning

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    Over the past decade, deep learning has had a revolutionary impact on a broad range of fields such as computer vision and image processing, computational photography, medical imaging and speech and language analysis and synthesis etc. Deep learning technologies are estimated to have added billions in business value, created new markets, and transformed entire industrial segments. Most of today’s successful deep learning methods such as Convolutional Neural Networks (CNNs) rely on classical signal processing models that limit their applicability to data with underlying Euclidean grid-like structure, e.g., images or acoustic signals. Yet, many applications deal with non-Euclidean (graph- or manifold-structured) data. For example, in social network analysis the users and their attributes are generally modeled as signals on the vertices of graphs. In biology protein-to-protein interactions are modeled as graphs. In computer vision & graphics 3D objects are modeled as meshes or point clouds. Furthermore, a graph representation is a very natural way to describe interactions between objects or signals. The classical deep learning paradigm on Euclidean domains falls short in providing appropriate tools for such kind of data. Until recently, the lack of deep learning models capable of correctly dealing with non-Euclidean data has been a major obstacle in these fields. This special section addresses the need to bring together leading efforts in non-Euclidean deep learning across all communities. From the papers that the special received twelve were selected for publication. The selected papers can naturally fall in three distinct categories: (a) methodologies that advance machine learning on data that are represented as graphs, (b) methodologies that advance machine learning on manifold-valued data, and (c) applications of machine learning methodologies on non-Euclidean spaces in computer vision and medical imaging. We briefly review the accepted papers in each of the groups

    Climate change, in the framework of the constructal law

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    Here we present a simple and transparent alternative to the complex models of Earth thermal behavior under time-changing conditions. We show the one-to-one relationship between changes in atmospheric properties and time-dependent changes in temperature and its distribution on Earth. The model accounts for convection and radiation, thermal inertia and changes in albedo (ρ) and greenhouse factor (γ). The constructal law is used as the principle that governs the evolution of flow configuration in time, and provides closure for the equations that describe the model. In the first part of the paper, the predictions are tested against the current thermal state of Earth. Next, the model showed that for two time-dependent scenarios, (δρ = 0.002; δγ = 0.011) and (δρ = 0.002; δγ = 0.005) the predicted equatorial and polar temperature increases and the time scales are (Δ<i>T</i><sub>H</sub> = 1.16 K; Δ<i>T</i><sub>L</sub> = 1.11 K; 104 years) and (0.41 K; 0.41 K; 57 years), respectively. In the second part, a continuous model of temperature variation was used to predict the thermal response of the Earth's surface for changes bounded by δρ = δγ and δρ = −δγ. The results show that the global warming amplitudes and time scales are consistent with those obtained for δρ = 0.002 and δγ = 0.005. The poleward heat current reaches its maximum in the vicinity of 35° latitude, accounting for the position of the Ferrel cell between the Hadley and Polar Cells
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