518 research outputs found

    Garantia de qualidade do processo de Catalogação de Recursos de Informação na Árvore do Conhecimento Agroenergia: ajustes dos apontamentos da auditoria.

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    A Agência de Informação Embrapa é um website responsável pela organização e disseminação da informação tecnológica (EMBRAPA, 2012). Por meio dele, o conhecimento gerado pela Embrapa e instituições de pesquisa parceiras ficam disponíveis para a sociedade brasileira. A organização dessas informações são dispostas hierarquicamente, da mais genérica para as mais específicas. Estas divisões possibilitam a aproximação com a estrutura de uma árvore, e por isso recebe o nome de Árvore do Conhecimento (AC) (ALVES et al., 2008). Cada Árvore do Conhecimento organiza informações de um produto ou tema e é composta por diversos ?nós?, local de descrição dos itens da hierarquia e associação de recursos de informação. Estes recursos de informação possuem diferentes tipos (texto, som, imagem, website, software, etc) e formatos (como doc, odt e pdf para textos), tornando-os fundamentais para suprir a necessidade de informação de cada usuário. Para garantir a qualidade e precisão na recuperação desses recursos, adotou-se padrões internacionais e recomendações específicas de seus usos para a descrição dos mesmos (também conhecida como catalogação), conforme o manual de descrição elaborado por Alves et al. (2008). Além disso, neste manual encontram-se definidas as etapas do macroprocesso de organização de informação tecnológica da Agência. Dentre elas, a pré-publicação do conteúdo e, na sequência, a auditoria de qualidade da catalogação dos recursos desse conteúdo. A AC Agroenergia é o estudo de caso relatado neste trabalho porque teve o seu conteúdo organizado pela Embrapa Informática Agropecuária e encontrava-se na etapa Auditoria de Catalogação. Esta árvore oferece informações sobre formas de obtenção de energia proveniente da agricultura, dividida em quatro grandes temas: Álcool, Biodiesel, Florestas, Resíduos (dejetos agropecuários da agricultura), além do acesso a recursos de informação na íntegra. Neste contexto, as atividades desenvolvidas para ajustes dos apontamentos da auditoria serão discutidas neste trabalho

    Trace elements and Pb isotope variations in galena from the onça gold deposit, Mato Grosso, Brazil: fluid mixing from hydrothermal and crustal sources

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    This study deals with the petrography of sulfídes and quartz veins, Pb isotopes, major and trace elements in galena, microthermometry and Raman spectrometry of fluid inclusions, with the objective of delineating temporal and spatial aspects of the fluid circulation patterns during the origin of the Onça gold deposit, Mato Grosso State, Brazil. The Pb isotope and mineral chemistry data indicate variable sources for the Pb isotopes, major (S and Pb) and trace elements (Sb, Ag, Zn and Se), with increases or decreases of the contents during the growth of the galena crystals. The results suggest that the variation may be due to the contamination of the hydrothermal solution by mixing with components derived from supracrustal host rocks of Pontes e Lacerda metavolcanic-sedimentary sequence. The mineral chemistry and fluids inclusion studies suggest two possible sources for the hydrothermal solutions: (1) deep solutions that originated during the regional metamorphism represented by the Aguapeí metamorphic event where the solutions present aqueous-carbonic composition and Iow salinity. Geologic control of the mineralization is in agreement with this hypothesis because the ore bodies are syntectonic with foliation formed during the Aguapeí event; (2) high contents of base metais indicates a plutonic influence in the origin of the fluids. Geologic controls also are in agreement with this hypothesis because pegmatitic intrusion was synchronous with the mineralizations. The Pb isotope and fluid inclusion relations allows the conclusions that the compositions of the hydrothermal solutes were variable during the emplacement of the quartz veins and the growth of galena crystals. The earlier solutes had hydrocarbons and were more radiogenic, whereas the later solutes had base metais and were less radiogenic. The Onça deposit originated during a metamorphic event by the effect of hydrothermal solutions related to plutonism, and with an important contribution from the host rocks as recorded by the influence of isotope, major and trace element compositions on the growth of ore-forming minerais.Este estudo compreende petrografia de sulfetos e veios de quartzo, elementos traços, maiores e isótopos de Pb em galena, microtermometria e espectrometria Raman em inclusões fluidas com o objetivo de delinear aspectos temporais e espaciais da circulação de fluídos durante a origem do depósito aurífero do Onça, Estado do Mato Grosso. Os resultados de isótopos de Pb e a química mineral indicam uma fonte variável para os isótopos de Pb e para elementos maiores (S e Pb) e elementos traços (Sb, Ag, Zn e Se) com aumentos e diminuições nos seus conteúdos durante o crescimento dos cristais de galena de forma que esta variação pode ser resultado da contaminação da solução hidrotermal pelas rochas supracrustais encaixantes da Seqüência Metavulcano-sedimentar Pontes e Lacerda. A química mineral e o estudo das inclusões fluídas sugerem dois tipos de fontes para as soluções hidrotermais: (1) soluções originadas em profundidade durante o metamorfismo regional representado pelo evento Aguapeí, com soluções aquocarbônicas e de baixa salinidade, hipótese corroborada pela concordância dos corpos de minério com a foliação regional gerada por este evento; (2) altos valores de metais básicos indicam uma influência plutônica na origem dos fluídos. Os isótopos de Pb e os estudos de inclusões fluídas analisadas conjuntamente permitem concluir que a composição das soluções hidrotermais foram variáveis durante o emplacement dos veios de quartzo e o crescimento dos cristais de galena. As soluções iniciais apresentam CR, na sua composição e são mais radiogênicas. As soluções finais apresentam metais básicos em sua composição e são menos radiogênicos. Como conclusão é possível sugerir que o depósito do Onça foi originado durante um evento metamórfico por soluções hidrotermais com influência de plutonismo, com uma importante contribuição das rochas encaixantes na composição isotópica do Pb, nos elementos maiores e traços durante o crescimento dos minerais de minério

    Wind power forecasting with machine learning: single and combined methods

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    In Portugal, wind power represents one of the largest renewable sources of energy in the national energy mix. The investment in wind power started several decades ago and is still on the roadmap of political and industrial players. One example is that by 2030 it is estimated that wind power is going to represent up to 35% of renewable energy production in Portugal. With the growth of the installed wind capacity, the development of methods to forecast the amount of energy generated becomes increasingly necessary. Historically, Numerical Weather Prediction (NWP) models were used. However, forecasting accuracy depends on many variables such as on-site conditions, surrounding terrain relief, local meteorology, etc. Thus, it becomes a challenge to obtain improved results using such methods. This article aims to report the development of a machine learning pipeline with the objective of improving the forecasting capability of the NWP’s to obtain an error lower than 10%.info:eu-repo/semantics/publishedVersio

    (U-th)/he ages from the fuorite mineralization of the Tanguá Alkaline intrusion

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    The Tanguá Alkaline Suite formed as a result of Mesozoic to Cenozoic magmatic events that affected the part of the South American Platform in Brazil’s southeast. The alkaline intrusion is composed of alkali-feldspar syenite with nepheline (pulaskites and umptekites), syenite (with or without the presence of pseudo-leucite), varied nepheline syenites (foyaites, micro-foyaites etc.) and alkaline magmatic breccias. The intrusion contains important fluorite mineralization, in the form of NE-SW oriented veins, which were economically extracted in recent decades at the Emitang Mine. This paper focuses on the analysis of these centimetric crystals of fluorite which vary in color from (yellow, to white and pur-ple.) associated with mineralization of Tanguá Body. Geochronological dating by (U-Th)/He of fluorite mineralization showed a wide range of ages, with the oldest age of 74 ± 3 Ma (Late Cretaceous) and the youngest of 0.11 ± 0.02 Ma (Late Pleistocene). Most ages are concentrated between 25 and 8 Ma (Miocene). The oldest age (74.0 ± 3 Ma) is associated with hydrothermal fluids percolating at the time of intrusion of the Tanguá Body. The other ages represent episodes of percolation of hydrothermal fluids and consequent growth of fluorite crystals. Of note is a set of Miocene ages that can be associated with regional tectonic events. This phase of flurite growth may be associated with the reactivation of basement faults and structures in the Tanguá region and the circulation of hydrothermal fluids associated with intrusion of younger dikes. The youngest ages may be associated with neotectonic reactivation of faults during neotectonic events

    Time matters in multiple sclerosis: can early treatment and long-term follow-up ensure everyone benefits from the latest advances in multiple sclerosis?

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    [Excerpt] Introduction The management of multiple sclerosis (MS) has been a neurology success story for the past 25 years. Advances in understanding of the disease mechanisms and the dynamic nature of the disease have brought around 12 disease-modifying therapies (DMTs) to market in many countries.[...]This study was funded by F Hoffmann-La Roche.info:eu-repo/semantics/publishedVersio

    The interaction of La3+ complexes of DOTA/DTPA-glycoconjugates with the RCA120 lectin : a saturation transfer difference (STD) NMR spectroscopic study

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    The study of ligand-receptor interactions using high resolution NMR techniques, namely the Saturation Transfer Difference (STD), is presented for the recognition process between La(III) complexes of DOTA mono(amide) and DTPA bis(amide) glycoconjugates and the galactose specific lectin Ricinus Communis agglutinin (RCA120). This new class of Gd(III)-based potential targeted MRI contrast agents (CAs), bearing one or two terminal sugar (galactosyl or lactosyl) moieties, has been designed for in vivo binding to ASGPR (the asialoglycoprotein receptor), which is specifically expressed at the surface of liver hepatocytes, with the aim of leading to a new possible diagnosis of liver pathologies. The in vitro affinity constants of the divalent La(III)- glycoconjugate complexes to RCA120, used as a simple, water soluble receptor model, were higher than those of the monovalent analogues. The combination of the experimental data obtained from the STD NMR experiments with molecular modelling protocols (Autodock 4.1) allowed us to predict the binding mode of mono and divalent forms of these CAs to the galactose 1 binding sites of RCA120. The atomic details of the molecular interactions allowed corroborating and supporting the interaction of both the sugar moieties and the linkers with the surface of the protein and thus, their contribution to the observed interaction stabilities.Fundação para a Ciência e a Tecnologia (FCT

    Sources of hepatic triglyceride accumulation during high-fat feeding in the healthy rat

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    Hepatic triglyceride (HTG) accumulation from peripheral dietary sources and from endogenous de novo lipogenesis (DNL) was quantified in adult Sprague-Dawley rats by combining in vivo localized 1H MRS measurement of total hepatic lipid with a novel ex vivo 2H NMR analysis of HTG 2H enrichment from 2H-enriched body water. The methodology for DNL determination needs further validation against standard methodologies. To examine the effect of a high-fat diet on HTG concentrations and sources, animals (n = 5) were given high-fat chow for 35 days. HTG accumulation, measured by in vivo 1H MRS, increased significantly after 1 week (3.85 ± 0.60% vs 2.13 ± 0.34% for animals fed on a standard chow diet, P < 0.05) and was maintained until week 5 (3.30 ± 0.60% vs 1.12 ± 0.30%, P < 0.05). Animals fed on a high-fat diet were glucose intolerant (13.3 ± 1.3 vs 9.4 ± 0.8 mM in animals fed on a standard chow diet, for 60 min glycemia after glucose challenge, P < 0.05). In control animals, DNL accounted for 10.9 ± 1.0% of HTG, whereas in animals given the high-fat diet, the DNL contribution was significantly reduced to 1.0 ± 0.2% (P < 0.01 relative to controls). In a separate study to determine the response of HTG to weaning from a high-fat diet, animals with raised HTG (3.33 ± 0.51%) after 7days of a high-fat diet reverted to basal HTG concentrations (0.76 ± 0.06%) after an additional 7 days of weaning on a standard chow diet. These studies show that, in healthy rats, HTG concentrations are acutely influenced by dietary lipid concentrations. Although the DNL contribution to HTG content is suppressed by a high-fat diet in adult Sprague-Dawley rats, this effect is insufficient to prevent overall increases in HTG concentrations. Copyright © 2008 John Wiley & Sons, Ltd

    Genome resequencing reveals multiscale geographic structure and extensive linkage disequilibrium in the forest tree Populus trichocarpa

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    This is the publisher’s final pdf. The article is copyrighted by the New Phytologist Trust and published by John Wiley & Sons, Inc. It can be found at: http://onlinelibrary.wiley.com/journal/10.1111/%28ISSN%291469-8137. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work.•Plant population genomics informs evolutionary biology, breeding, conservation and bioenergy feedstock development. For example, the detection of reliable phenotype–genotype associations and molecular signatures of selection requires a detailed knowledge about genome-wide patterns of allele frequency variation, linkage disequilibrium and recombination.\ud •We resequenced 16 genomes of the model tree Populus trichocarpa and genotyped 120 trees from 10 subpopulations using 29 213 single-nucleotide polymorphisms.\ud •Significant geographic differentiation was present at multiple spatial scales, and range-wide latitudinal allele frequency gradients were strikingly common across the genome. The decay of linkage disequilibrium with physical distance was slower than expected from previous studies in Populus, with r² dropping below 0.2 within 3–6 kb. Consistent with this, estimates of recent effective population size from linkage disequilibrium (N[subscript e] ≈ 4000–6000) were remarkably low relative to the large census sizes of P. trichocarpa stands. Fine-scale rates of recombination varied widely across the genome, but were largely predictable on the basis of DNA sequence and methylation features.\ud •Our results suggest that genetic drift has played a significant role in the recent evolutionary history of P. trichocarpa. Most importantly, the extensive linkage disequilibrium detected suggests that genome-wide association studies and genomic selection in undomesticated populations may be more feasible in Populus than previously assumed

    PETROGRAFIA, GEOQUÍMICA E GEOCRONOLOGIA DAS ROCHAS GRANÍTICAS DA OROGENIA SAN IGNÁCIO (BOLÍVIA): Geology, geochemistry and geocronology of the granitic rocks of San Ignácio Orogeny (BOLÍVIA)

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    This contribution aims to characterize the Proterozoic granites of San Ignacio orogeny, western Bolivia, describing their chemical composition, U-Pb and Sm/Nd isotopic to identify sources and process of the crustal formation. The results of chemical and isotopic granitoids of Cachuela, Motacusal and Talcoso, present U/Pb age in zircon between 1307 and 1333 Ma, suggesting an important epoch of generation of granitoids in the Bolivian pre-Cambrian. Chemistry (A-Type granites) and Nd isotopes (εNd(1330) between -0.77 and -3.86) signatures here reported suggest an anorogenic environment and the spider diagram indicate the within-plates tectonic setting for the formation of these granites, instead of arc-related environment is suggested in the literature for these rocks. The data here reported suggest a geological evolution for the Bolivian pre-Cambrian composed of the San Ignacio event is represented by magmatic arc with participation of continental crust previously formed representing an important collisional period in the SW Amazonian craton.Esta contribuição visa caracterizar os granitos do Proterozóico de San Ignacio orogenia, ocidental da Bolívia, descrevendo sua composição química e isótopos de U-Pb e Sm / Nd para identificar fontes e processos de formação desyas rochas. Os resultados de granitoides químicos e isotópicos de Cachuela, Motacusal e Talcoso, apresentam idade U / Pb em zircão entre 1307 e 1333 Ma, sugerindo uma época importante de geração de granitoides no pré-Cambriano boliviano. Química (granitos de tipo A) e isótopos de Nd (εNd (1330) entre -0,77 e -3,86) aqui relatados para o pré-Cambriano boliviano indica que o evento San Ignacio, é representado por um arco magmático com participação de crosta continental previamente formada, representando um importante período colional no craton Amazônico da Amazônia
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