345 research outputs found

    Cultivo de colza para produção de biodiesel

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    Cultivo de colza para produção de biodieselO presente trabalho teve como objetivo principal estudar a adaptação da colza às condições de cultivo do Nordeste de Portugal. Procedeu-se ainda à determinação laboratorial do teor de óleo em sementes de colza. A partir de óleos alimentares usados foi produzido biodiesel e determinados os índices de iodo e de acidez, de acordo com as normas EN14111 e EN14104, respetivamente. Aspetos pouco conhecidos sobre a mecanização de operações culturais como a sementeira e colheita foram estudados, tendo-se encontrado algumas respostas para as características que o semeador a eleger deve conter e regulações a efetuar na ceifeira- -debulhadora a usar na colheita. A produção de colza em campo foi bastante penalizada pelas condições de seca severa que se registaram no Inverno e início da Primavera desse mesmo ano, não tendo sido possível observar efeitos significativos entre as diferentes modalidades experimentais. A produção média de colza em cada um dos talhões foi da ordem de 1000 kg semente ha-1. O teor em óleo das sementes de colza variou entre 41.7 e 42.0%. Relativamente ao índice de acidez do biocombustível obteve-se 0.16 g KOH/g amostra e quanto ao índice de iodo registou-se o valor de 130.32 g iodo/100 g de biocombustível

    Co-silencing of human Bub3 and dynein highlights an antagonistic relationship in regulating kinetochore-microtubule attachments

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    We previously reported that the spindle assembly checkpoint protein Bub3 is involved in regulating kinetochore-microtubule (KT-MT) attachments. Also, Bub3 was reported to interact with the microtubule motor protein dynein. Here we examined how this interaction contributes to KT-MT attachments. Depletion of Bub3 or dynein induced misaligned chromosomes, consistent with their role in KT-MT attachments. Unexpectedly, co-silencing of both proteins partially suppressed the misalignment phenotype and restored chromosome congression. Consistent with these observations, KT-MT attachments in co-depleted cells were stable, able to drive chromosome congression, and produce inter-and intra-kinetochore stretch, indicating they are functional. We suggest that a mutual antagonism exists between Bub3 and dynein to ensure optimal KT-MT attachments. (C) 2015 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.CESPU [02-GCQF-CICS-2011N]; FCT - Fundacao para a Ciencia e a Tecnologia [CEQUIMED-PEst-OE/SAU/UI4040/2014]; FCT [SFRH/BD/90744/2012]info:eu-repo/semantics/publishedVersio

    CARACTERIZAÇÃO DAS UNIDADES GEOAMBIENTAIS E CONDIÇÕES DE USO E COBERTURA DO ESTUÁRIO DO RIO ARACATIAÇU/CE

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    O ambiente estuarino é um ponto de encontro entre as águas continentais e marinhas, proporcionando assim um ambiente de intensas dinâmicas físico-químicas e biológicas. Este estudo teve por objetivo caracterizar, a partir da análise integrada, as condições geoambientais atuais e o uso e cobertura do estuário do rio Aracatiaçu, localizado no município de Amontada, na costa oeste do estado do Ceará

    Carbon footprint of apple and pear : orchards, storage and distribution

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    Apple and pear represent 51% of fresh fruit orchards in Portugal. This paper presents a life-cycle (LC) greenhouse gas (GHG) assessment (so-called carbon footprint) of 3 apple and 1 pear Portuguese production systems. An LC model and inventory were implemented, encompassing the farm stage (cultivation of fruit trees in orchards), storage and distribution (transport to retail). The functional unit considered in this study was 1 kg of distributed fruit (at retail). Four different LC inventories for orchards were implemented based on data collected from three farms. Inventory data from two storage companies were also gathered. The main results show that the GHG emissions of apple and pear ranged between 192 and 229 gCO2eq kgfruit-1. The GHG emissions (direct and indirect) from the cultivation phase ranged from 36% to 60% of total emissions. Fruit storage, which lasted for as much as 8-10 months, was also responsible for significant emissions due to high energy requirements

    Patchiness and Demographic Noise in Three Ecological Examples

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    Understanding the causes and effects of spatial aggregation is one of the most fundamental problems in ecology. Aggregation is an emergent phenomenon arising from the interactions between the individuals of the population, able to sense only -at most- local densities of their cohorts. Thus, taking into account the individual-level interactions and fluctuations is essential to reach a correct description of the population. Classic deterministic equations are suitable to describe some aspects of the population, but leave out features related to the stochasticity inherent to the discreteness of the individuals. Stochastic equations for the population do account for these fluctuation-generated effects by means of demographic noise terms but, owing to their complexity, they can be difficult (or, at times, impossible) to deal with. Even when they can be written in a simple form, they are still difficult to numerically integrate due to the presence of the "square-root" intrinsic noise. In this paper, we discuss a simple way to add the effect of demographic stochasticity to three classic, deterministic ecological examples where aggregation plays an important role. We study the resulting equations using a recently-introduced integration scheme especially devised to integrate numerically stochastic equations with demographic noise. Aimed at scrutinizing the ability of these stochastic examples to show aggregation, we find that the three systems not only show patchy configurations, but also undergo a phase transition belonging to the directed percolation universality class.Comment: 20 pages, 5 figures. To appear in J. Stat. Phy

    Carbon footprint of apple and pear: orchards, storage and distribution

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    Apple and pear represent 51% of fresh fruit orchards in Portugal. This paper presents a life-cycle (LC) greenhouse gas (GHG) assessment (so-called carbon footprint) of 3 apple and 1 pear Portuguese production systems. An LC model and inventory were implemented, encompassing the farm stage (cultivation of fruit trees in orchards), storage and distribution (transport to retail). The functional unit considered in this study was 1 kg of distributed fruit (at retail). Four different LC inventories for orchards were implemented based on data collected from three farms. Inventory data from two storage companies were also gathered. The main results show that the GHG emissions of apple and pear ranged between 192 and 229 gCO2eq kgfruit-1. The GHG emissions (direct and indirect) from the cultivation phase ranged from 36% to 60% of total emissions. Fruit storage, which lasted for as much as 8-10 months, was also responsible for significant emissions due to high energy requirements.Project ECODEEP (Eco-efficiency and Eco-management in the Agro Industrial sector, FCOMP–05–0128–FEDER–018643) and the Portuguese Science and Technology Foundation projects: MIT/SET/0014/2009, PTDC/SEN-TRA/117251/201

    Corpo, maturação biológica e actividade física: um olhar interactivo em crianças e jovens madeirenses

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    Cada vez mais a sociedade moderna é olhada através da sua condição física, enquanto factor de bem-estar, saúde, qualidade de vida e longevidade dos seus membros. Os indicadores demográficos actuais da população madeirense apontam no sentido de uma considerável componente juvenil, adolescente e jovem. No entanto, a evolução demográfica prevista, decorrente de um acentuado decréscimo da natalidade, leva a prever um comportamento diverso da pirâmide de idades, assumindo particular ênfase as questões relacionadas com o estudo e a investigação do corpo, a procura de padrões, a descrição normativa, a interpretação das mudanças e o espaço morfológico externo, que se vem enquadrar no território de investigação reservado à somatotipologia

    Alcalóides de Duguetia trunciflora Maas (Annonaceae)

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    From the ethanolic extract of the leaves and thin branches of Duguetia trunciflora Maas (Annonaceae) six alkaloids were isolated, being one benzylisoquinoline: reticuline¹, four tetrahydroprotoberberine:,tetrahydro-palmatine², tetrahydrojathrorrizine³, discretamine4, thaicanine5, and one berberine: jathrorrizine6. These alkaloids were identified through ¹H and 13C NMR spectroscopic technics. The alkaloids 1, 3, 5 and 6 are being cited for the first time on Duguetia genus

    Volatile and glycosidically bound composition of Loureiro and Alvarinho wines

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    Composition of Loureiro and Alvarinho wines from the Vinhos Verdes region, respecting free volatile compounds as well as glycosidically bound aroma precursors, was exhaustively determined by GC-MS after adsorption on XAD-2 resin. On the whole, were identified and quantified 120 volatile compounds in the free fraction and 77 glycosidically bound compounds, belonging to C6-compounds, alcohols, fatty acids ethyl esters, esters of organic acids, acetates, monoterpenic alcohols, monoterpenic oxides and diols, C13-norisoprenoids, volatile phenols, volatile fatty acids and carbonyl compounds. Globally, the wines of the two cultivars present similar composition on volatiles. However, respecting varietal compounds, Loureiro wines are richer than Alvarinho ones with regard to C6-compounds and monoterpenic compounds, occurring the opposite for volatile phenols. It was also demonstrate that wines of both varieties may benefit the aroma reserve, present as glycoconjugates, as it is susceptible of being technologically explored. Linalool, Ho-trienol, α-terpineol, contributing with fruity and floral notes, and β-damascenone mostly for Alvarinho, confering tropical fruit notes, are the varietal compounds which may particularly influence the aroma of these wines. Respecting fermentative compounds, Alvarinho is also particularly rich in fatty acids ethyl esters related to lipid metabolism and acetates of fusel alcohols, which can provide it a fruity character; Loureiro contains higher levels of esters of organic acids and 2-phenylethanol, conferring fruity and floral notes. Sensory analysis agree with chemical analyses showing a pronounced tree and tropical fruit character for Alvarinho wines while Loureiro wines present more intense citrus fruit notes.Centre of Biological Engineering of Universidade do Minho; Estação Vitivinícola Amândio Galhano (EVAG); Solar de Serrade; EVAG; Comissão de Viticultura da Região dos Vinhos Verdes
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