159 research outputs found

    World Press Photo 2012: the discursive construction of the Arab Spring

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    O presente artigo pretende analisar a forma como o fenómeno da Primavera Árabe foi retratado nas fotografias vencedoras do concurso World Press Photo em 2012. As fotografias jornalísticas, embora se apresentem como índices do real, condicionam frequentemente a percepção dos indivíduos e influenciam as suas práticas sociais. Também as fotografias vencedoras do World Press Photo, um dos concursos mais prestigiados de fotojornalismo, em 2012 não fogem ao construtivismo discursivo que molda a representação e a percepção dos acontecimentos. A partir da análise crítica do discurso, nomeadamente dos instrumentos teóricos da semiótica barthesiana e da semiótica social de Gunther Kress e Theo van Leeuwen, procurámos interpretar as 38 fotografias vencedoras do World Press Photo 2012, a fim de reflectirmos sobre o modo como contribuíram para a compreensão da Revolta Árabe e como despertaram o nosso interesse e a nossa imaginação para o desenrolar do conflito.ABSTRACT:This article aims to analyze how the Arab Spring phenomenon was represented in the award-winning photographs of the World Press Photo contest in 2012. Although news photographs are usually seen as indexes of the real, they often limit the perception of individuals and influence their social practices. Also the winning photographs in 2012 of the World Press Photo, one of the most prestigious photojournalism contests, do not escape the discursive constructivism that shapes the representation and perception of events. Drawing from critical discourse analysis, namely from the theoretical tools of barthesian semiotics and Gunther Kress’s and Theo van Leeuwen’s social semiotics, we sought to interpret the 38 award-winning photographs of the World Press Photo contest in 2012, in order to reflect on the way they have contributed to our understanding of the Arab Revolt and aroused our interest and imagination to the unfolding of the conflict.info:eu-repo/semantics/publishedVersio

    Growth and production of cowpea cultivated with liming and nitrogen fertilization in the Eastern Amazon.

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    No nordeste do Pará, o feijão-caupi é uma das principais fontes proteicas da população. Este estudo teve como objetivo avaliar os efeitos da calagem, a fertilização mineral P e K, e a combinação de inoculação de sementes com Rizobium associada à suplementação mineral N no crescimento e produção de cultivares de feijão-caupi. Dois experimentos foram realizados em dois anos consecutivos na Universidade Federal Rural da Amazônia (Capitão Poço-PA). Um randomizado projeto experimental de bloco com parcelas subdivididas foi utilizado com quatro replicações, duas cultivares de feijão-caupi (BRS Tapaihum e BRS Marataoã) e seis tratamentos de fertilização e calagem: i) sem fertilização e sem calagem; ii) P e K fertilização mineral, calagem e inoculação de sementes com Rizobium; iii) Fertilização mineral P e K e inoculação de sementes com Rizobium; iv) Adubação mineral n, P e K e calgem; v) Fertilização mineral P e K e calagem; e vi) N, P e fertilização mineral K, calagem e inoculação de sementes com Rizobium. O feijão-caupi respondeu a calagem e P e K fertilização mineral, mas não fertilização N. Não houve diferença entre o fornecimento de N através da inoculação de sementes ou fertilização mineral. Assim, sugere-se inocular sementes com Rizóbio, a fim de manter a reserva n do solo.In the northeastern of Pará, cowpea is one of the main protein sources of the population. This study aimed to evaluate the effects of liming, the P and K mineral fertilization, and the combination of seed inoculation with Rhizobium associated with mineral N supplementation in the growth and production of cowpea cultivars. Two experiments were carried out in two consecutive years at the Federal Rural University of Amazonia (Capitão Poço-PA). A randomized block experimental design with subdivided plots was used with four replications, two cowpea cultivars (BRS Tapaihum and BRS Marataoã) and six fertilization and liming treatments: i) without fertilization and without liming; ii) P and K mineral fertilization, liming and seed inoculation with Rhizobium; iii) P and K mineral fertilization and seed inoculation with Rhizobium; iv) N, P and K mineral fertilization and liming; v) P and K mineral fertilization and liming; and vi) N, P and K mineral fertilization, liming and seed inoculation with Rhizobium. Cowpea responded to liming and P and K mineral fertilization, but not N fertilization. There was no difference between the supply of N through seed inoculation or mineral fertilization. Thus, it is suggested to inoculate seeds with Rhizobium in order to maintain the soil N reserv

    Impact of Si on C, N, and P stoichiometric homeostasis favors nutrition and stem dry mass accumulation in sugarcane cultivated in tropical soils with different water regimes

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    Studies with silicon (Si) in sugarcane indicate a greater response in productivity in plants under stress, and the underlying mechanisms of Si in the crop are poorly reported. In this context, the benefits of Si in the crop’s stem production are expected to occur at the C:N:P stoichiometry level in plant tissues, benefiting plants with and without stress. However, the extension of this response may vary in different soils. Thus, this research aimed to evaluate if fertigation with Si modifies the C:N:P stoichiometry and if it can increase sugarcane’s nutritional efficiency and vegetative and productive parameters. Therefore, three experiments were installed using pre-sprouted seedlings to cultivate sugarcane in tropical soils belonging to the Quartzarenic Neosol, Eutrophic Red Latosol, and Dystrophic Red Latosol classes. The treatments comprised a 2 × 2 factorial scheme in each soil. The first factor was composed without water restriction (water retention = 70%; AWD) and with water restriction (water retention = 35%; PWD). The second factor presented Si concentrations (0 mM and 1.8 mM) arranged in randomized blocks with five replications. Fertigation with Si increases the Si and P concentration, the C and N efficiency, the C:N ratio, and the dry mass production. However, it decreases the C and N concentration and the C:P, C:Si, and N:P ratios in sugarcane leaves and stems regardless of the water regime adopted in the three tropical soils. Cluster and principal components analysis indicated that the intensity of the beneficial effects of Si fertigation on sugarcane plants varies depending on the cultivation soil and water conditions. We found that Si can be used in sugarcane with and without water stress. It changes the C:N:P homeostasis enough to improve the nutritional efficiency of C, P, N, and, consequently, the dry mass accumulation on the stems, with variation in the different cultivated soils

    Production of oil palm under phosphorus, potassium and magnesium fertilization

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    ABSTRACT Oil palm production is strategic in the Amazon with high productive potential, but information on its fertilization is still relatively scarce for the region. The objective of this work was to evaluate the effects of phosphorus, potassium and magnesium fertilizations on oil palm production in different years in the state of Pará, Brazil. The study was conducted in Tailândia, Northeastern of Pará, Eastern Amazon, Brazil. A randomized block design was used in a 4 x 2 x 3 x 2 factorial scheme, with four levels of phosphorus, two sources of phosphorus, three levels of potassium and two levels of magnesium. Oil palm production responded positively to the increase in phosphorus levels, and until the eighth year of age of the plants, there was greater production when triple superphosphate was applied. From the ninth year onwards, fertilization with phosphine provided a production equal to the supply of phosphorus with triple superphosphate. The application of potassium chloride increased the number, weight and production of the bunches from the sixth year. The supply of magnesium sulfate increased the average weight of the bunches. Thus, phosphorus, potassium and magnesium fertilizations become essential to increase oil palm production in the Northeast of Pará

    Micronutrients concentrations in leaves of oil palm trees fertilized with phosphorus, potassium, and magnesium.

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    O manejo de micronutrientes em palmeiras de óleo na Amazônia brasileira ainda é subdesenvolvido; assim, informações sobre as demandas das plantas e suas interações com outros nutrientes são necessários para criar procedimentos de manejo adequados. O objetivo deste trabalho foi para avaliar os efeitos da fertilização de fosfato, potássio e magnésio no micronutriente concentrações em folhas de palmeiras de óleo. O experimento foi realizado na Amazônia brasileira em um projeto de bloco randomizado em um esquema fatorial 4 x 2 x 3 x 2, usando quatro Níveis de fósforo, duas fontes de fósforo (fosfato natural e superfosfato triplo), três níveis de potássio e dois níveis de magnésio. A fertilização fosfato aumentou o concentrações de boro, cloro e ferro nas folhas, enquanto cobre e manganês concentrações nas folhas diminuíram com o aumento das doses de fósforo.The management of micronutrients in oil palm trees in the Brazilian Amazon is still underdeveloped; thus, information on plant demands and their interactions with other nutrients is required to create adequate management procedures. The objective this work was to evaluate the effects of phosphate, potassium, and magnesium fertilization on micronutrient concentrations in leaves of oil palm trees. The experiment was carried out in the Brazilian Amazon in a randomized block design in a 4 x 2 x 3 x 2 factorial scheme, using four phosphorus levels, two phosphorus sources (natural phosphate and triple superphosphate), three potassium levels and two magnesium levels. Phosphate fertilization increased the concentrations of boron, chlorine, and iron in leaves, while copper and manganese concentrations in leaves decreased with increased doses of phosphorus. Among the phosphorus sources, triple superphosphate provided higher chlorine concentrations in leaves. Potassium fertilization increased only chlorine concentrations in leaves, while magnesium supply did not alter micronutrient concentrations in leaves. Thus, phosphorus and potassium fertilizers are essential to provide adequate micronutrient concentrations in leaves of oil palm trees

    Discontinuity detection in the shield metal arc welding process.

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    This work proposes a new methodology for the detection of discontinuities in the weld bead applied in Shielded Metal ArcWelding (SMAW) processes. The detection system is based on two sensors?a microphone and piezoelectric?that acquire acoustic emissions generated during the welding. The feature vectors extracted from the sensor dataset are used to construct classifier models. The approaches based on Artificial Neural Network (ANN) and Support Vector Machine (SVM) classifiers are able to identify with a high accuracy the three proposed weld bead classes: desirable weld bead, shrinkage cavity and burn through discontinuities. Experimental results illustrate the system?s high accuracy, greater than 90% for each class. A novel Hierarchical Support Vector Machine (HSVM) structure is proposed to make feasible the use of this system in industrial environments. This approach presented 96.6% overall accuracy. Given the simplicity of the equipment involved, this system can be applied in the metal transformation industries

    Contribution of Pueraria phaseoloides L. in the cycling of macronutrients in oil palm plantations

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    O uso de culturas de cobertura tornou-se uma prática comum em plantações de dendê, garantindo maior sustentabilidade para os agroecosistemas, aumentando o ciclismo de nutrientes e proporcionando maior economia no uso de fertilizantes minerais. Nesse sentido, o objetivo deste estudo foi avaliar o acúmulo de macronutrientes (N, P, K, Ca, Mg e S) em plantas tropicais kudzu (Pueraria phaseoloides L.) em plantações de dendê. O experimento foi realizado no município de Tailândia, Pará, utilizando um projeto experimental completamente randomizado, quatro replicações e sete tratamentos (idades de dendê). O acúmulo de macronutrientes foi obtido através do produto de concentrações de nutrientes e a atéria seca da antena parte dos vivos, mortos e cobertura total de kudzu tropical. A ordem de acumulação total de nutrientes cicluidos por leguminosas foi ca, N, K, Mg, P e S. Tropical kudzu, como um cobrir planta, contribui para o ciclismo de nutrientes em plantações de dendê, mas esse benefício diminuiu com a era das palmeiras.The use of cover crops has become a common practice in oil palm plantations, ensuring greater sustainability to agroecosystems, increasing nutrient cycling and providing greater savings in the use of mineral fertilizers. In this sense, the objective of this study was to evaluate the accumulation of macronutrients (N, P, K, Ca, Mg and S) in tropical kudzu plants (Pueraria phaseoloides L.) in oil palm plantations. The experiment was carried out in the municipality of Tailândia, Pará State, using a completely randomized experimental design, four replications and seven treatments (ages of oil palm). The accumulation of macronutrients was obtained through the product of nutrient concentrations and the dry matter of the aerial part of the living, dead and total cover of tropical kudzu. The order of total accumulation of cycled nutrients by legumes was Ca, N, K, Mg, P and S. Tropical kudzu cultivation, as a cover plant, contributes to nutrient cycling in oil palm plantations, but this benefit decreased with the age of palm oil trees

    12,500+ and counting: biodiversity of the Brazilian Pampa

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    Knowledge on biodiversity is fundamental for conservation strategies. The Brazilian Pampa region, located in subtropical southern Brazil, is neglected in terms of conservation, and knowledge of its biodiversity is fragmented. We aim to answer the question: how many, and which, species occur in the Brazilian Pampa? In a collaborative effort, we built species lists for plants, animals, bacteria, and fungi that occur in the Brazilian Pampa. We included information on distribution patterns, main habitat types, and conservation status. Our study resulted in referenced lists totaling 12,503 species (12,854 taxa, when considering infraspecific taxonomic categories [or units]). Vascular plants amount to 3,642 species (including 165 Pteridophytes), while algae have 2,046 species (2,378 taxa) and bryophytes 316 species (318 taxa). Fungi (incl. lichenized fungi) contains 1,141 species (1,144 taxa). Animals total 5,358 species (5,372 taxa). Among the latter, vertebrates comprise 1,136 species, while invertebrates are represented by 4,222 species. Our data indicate that, according to current knowledge, the Pampa holds approximately 9% of the Brazilian biodiversity in an area of little more than 2% of Brazil’s total land The proportion of species restricted to the Brazilian Pampa is low (with few groups as exceptions), as it is part of a larger grassland ecoregion and in a transitional climatic setting. Our study yielded considerably higher species numbers than previously known for many species groups; for some, it provides the first published compilation. Further efforts are needed to increase knowledge in the Pampa and other regions of Brazil. Considering the strategic importance of biodiversity and its conservation, appropriate government policies are needed to fund studies on biodiversity, create accessible and constantly updated biodiversity databases, and consider biodiversity in school curricula and other outreach activitie
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