412 research outputs found

    Estimativa do parentesco numa população de melhoramento de Eucalyptus globulus através de microsatélites nucleares

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    É situação comum desconhecer-se o grau de parentesco entre a população na origem da maioria dos programas de melhoramento genético de espécies florestais. Para resolver este problema, desenvolvemos um protocolo de avaliação do parentesco utilizando 125 indivíduos e 16 microssatélites, da população base ou de referência (PR) de Eucalyptus globulus do RAIZ. Através da recombinação gamética in silico foram simulados 105 indivíduos com diferentes graus de parentesco: descendentes de autopolinização, meiosirmãos, irmãos completos e indivíduos não aparentados. Por simulação Monte-Carlo foram calculados o valor médio e a variância associada à média dos diferentes grupos de parentesco, com quatro coeficientes de similaridade genética. Compararam-se as funções densidade dos diferentes grupos de parentesco, obtidas com quatro coeficientes de parentesco, utilizando o valor crítico correspondente à intercepção das funções densidade dos indivíduos não aparentados e dos meios-irmãos. O estimador escolhido foi aplicado à PR. Detectaram-se 4,4% de pares de indivíduos potencialmente aparentados, com um erro de tipo II de 8%. Inferimos também, o parentesco de um conjunto de 24 clones elite e encontrámos 4 pares que são potencialmente aparentados. Futuros cruzamentos entre estes indivíduos deverão ser evitados

    Tourism And Urbanization: Environmental Problem Of The Araruai Lagoon, State Of Rio De Janeiro, Brazil

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    The Araruama Lagoon (Rio de Janeiro) is known for its scenic beauty and natural resources, factors that have led to the economic expansion of the region. In recent decades, tourism and property speculation have been key to the urban development of the municipalities surrounding this Lagoon. Using secondary data and a theoretical framework based on Political Ecology and Critical Environmental Education, this article seeks to analyze the correlations between the development processes of the towns surrounding the Lagoon and the impact of these processes on the environmental quality of its ecosystem. In recent years, the evolution of parameters studied revealed that the imbalance in terms of the sustainable development of the region has damaged the health of this body of water. Large quantities of fresh water, as well as domestic and industrial effluents discharged without appropriate treatment in the Lagoon, have overloaded the ecological system, with negative effects for the entire economy in the surrounding area.194598

    Efeitos sinergistas da atividade antioxidante de cogumelos comestíveis: mistura de extratos fenólicos e polissacarídicos de Boletus edulis e Marasmius oreades.

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    Neste trabalho, avaliou-se a atividade antioxidante de diferentes misturas de Marasmius oreades e Boletus edulis (12,5/87,5, 25/75, 50/50, 75/25, 87,5/12,5) e comparou-se com os controlos (amostras individuais), com o objetivo de verificar qual das misturas contribui para efeitos sinergistas. As propriedades antioxidantes foram avaliadas por quatro métodos químicos e bioquímicos, sendo ainda determinados os fenóis totais (extratos fenólicos) e o teor em polissacáridos (extratos polissacarídicos). Foram observadas três tipos de interações utilizando as diferentes misturas de cogumelos: efeitos aditivos, sinergistas e antagonistas. Os resultados obtidos mostraram diferentes comportamentos nos ensaios de atividade antioxidante de acordo com as proporções utilizadas, indicando que as misturas de cogumelos permitem a ocorrência de diferentes interações químicas entre os compostos obtidos em cada espécie. Todas as diferentes proporções utilizadas de cada cogumelo demonstraram ter atividade antioxidante e, independentemente das proporções utilizadas, os extratos polissacarídicos apresentaram maior atividade antioxidante que os extratos fenólicos. Verificou-se também que a mesma mistura pode induzir um efeito sinergista num método de atividade antioxidante e um efeito antagonista noutro método de atividade antioxidante

    Insights in the antioxidant synergistic effects of combined edible mushrooms: phenolic and polysaccharidic extracts of Boletus edulis and Marasmius oreades

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    In a previous work, we reported the presence of Marasmius oreades in mixtures with antioxidant synergistic effects, and the mixture Boletus edulis and Marasmius oreades (50% of each) as having the highest antioxidant activity, but without synergism among the phenolic extracts. Herein, phenolic and polysaccharidic extracts from both species were combined in different proportions (12.5, 25, 50, 75 and 87.5%) and compared to controls (individual samples), in order to give insight in the contribution of each species to antioxidant synergistic effects. The antioxidant activity of the individual or combined extracts obtained from both edible mushrooms was evaluated through their 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity, reducing power, -carotene bleaching inhibition and lipid peroxidation inhibition in brain homogenates using thiobarbituric acid reactive substances (TBARS) assay. Synergism was the main observed effect among the combined extracts, either phenolic or polysaccharidic. However, the effect of each B. edulis and M. oreades proportion was not the same for all antioxidant activity assays. In fact, the same mixture exhibited sometimes opposite behaviours according with the performed antioxidant activity assay

    Optimizing the choice of microsatellite markers for fingerprinting eucalyptus

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    In this study we have analyzed the information provided by 17 publicly available Eucalyptus microsatellite (SSR) markers (Brondani et al. 1998, 2002; Jones et al. 2002; Steane et al. 2001) in the context of genetic identification within a sample of 140 individuals from an elite collection (denoted hereafter base) of RAIZ genetic improvement population

    Effect of vineyard floor management practices on water use: A case study at a terroir of the "Dão" winegrowing region in Portugal

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    Aiming to evaluate the effect of vineyard floor management practices on water use and vine performance, a field experiment was carried out at the Dão Wine Research Station, located at Nelas, Center Portugal. The experiment was set up in 2010 in a mature vineyard planted with the red grape variety ‘Touriga Nacional’, using a 2x2 factorial design with the following treatments: inter-row soil management (permanent resident vegetation vs. soil tillage) and undervine floor management (mulch vs. herbicide). In this paper it will be presented data from 2013 growing season (four seasons after experiment setup). The volumetric soil moisture, assessed with a capacitance probe to a 1.5 m depth, showed a decreasing pattern throughout the growing season in all treatments with the resident vegetation presenting lower values as compared to the tillage treatment, while no significant differences were observed between the two undervine floor management practices. From budburst to flowering the resident vegetation treatment showed a higher soil water depletion (up to 1.5 m depth) than the tillage treatment but the relative situation was reversed during the flowering-veraison period, while no significant differences were observed during the ripening period. Vine stem water potential values showed a decreasing pattern along the season attaining very low values during September but with no significant differences between treatments. In general the soil management practices did not significantly affect vine vigor, yield and berry composition however, since these results are only from one season, further data analysis in ongoing in order to allow stronger conclusions.info:eu-repo/semantics/publishedVersio

    Scattering from supramacromolecular structures

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    We study theoretically the scattering imprint of a number of branched supramacromolecular architectures, namely, polydisperse stars and dendrimeric, hyperbranched structures. We show that polydispersity and nature of branching highly influence the intermediate wavevector region of the scattering structure factor, thus providing insight into the morphology of different aggregates formed in polymer solutions.Comment: 20 pages, 8 figures To appear in PR

    Influence de l'effeuillage sur l'efficience thermique de l'accumulation des anthocyanes dans la baie

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    The aim of this work was to analyse the effects of leaf removal on Touriga Nacional berry temperature and consequent thermal efficiency for anthocyanins biosynthesis. The field experiment was located at Dão Wine Research Station, Nelas, Portugal in an adult vineyard planted with North-South oriented rows, with the red grape variety Touriga Nacional grafted on 110R rootstock. The vines were trained on a vertical shoot positioning, spur-pruned on a bilateral Royat cordon system and deficit irrigated (50% ETc). The experimental design was a randomized complete block design with four replications of twelve vines per elemental plot, and the following two treatments: basal leaf removal (LR) and a control non-defoliated (ND). Berry temperature (Tb) was measured continuously during the second half (3rd to 19th September) of the 2009 ripening period using two-junction, fine-wires copper-constantan thermocouples manually inserted into the berries and connected to a data logger. A sample of clusters located in different canopy positions (exposed and internal; facing East and West) of 4 vines per treatment were used. To quantify the effect of Tb on anthocyanins biosynthesis, the berry hourly mean temperatures were converted into normal heat hours (NHH) and accumulated per day (NHHd) and per monitoring period (NHHc). For quantification of thermal requirements for anthocyanins synthesis and accumulation, a minimum of 10°C, a maximum of 35°C, and an optimum of 26°C were used. Meteorological variables were measured at an automatic weather station installed within the experimental plot. For all days of the monitoring period, daily average berry temperature (dTb) of all monitored berries was lower in ND treatment than in LR, being the maximum differences between treatments registered on 11th September. The highest dTb differences between treatments were registered on the clusters located at the west side of the canopy on 7th September while dTb of the clusters located in the centre of the canopy was less affected by leaf removal. The control non-defoliated treatment (ND) presented a significantly higher NHHc than that of LR being the higher differences presented by the clusters located in the west side. The lowest differences in NHHc were obtained in the clusters located in the centre of the canopy. Our results show that the thermal efficiency for berry anthocyanins accumulation was significantly affected by leaf removal and that this effect was dependent of the meteorological conditions, time of the day and berry/cluster location into the vine canopy

    Rods Near Curved Surfaces and in Curved Boxes

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    We consider an ideal gas of infinitely rigid rods near a perfectly repulsive wall, and show that the interfacial tension of a surface with rods on one side is lower when the surface bends towards the rods. Surprisingly we find that rods on both sides of surfaces also lower the energy when the surface bends. We compute the partition functions of rods confined to spherical and cylindrical open shells, and conclude that spherical shells repel rods, whereas cylindrical shells (for thickness of the shell on the order of the rod-length) attract them. The role of flexibility is investigated by considering chains composed of two rigid segments.Comment: 39 pages including figures and tables. 12 eps figures. LaTeX with REVTe

    Molecular estimates of similarity in Eucalyptus globulus

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    The base populations used in most forest tree genetic improvement programs usually lack detailed pedigree information. Molecular markers, such as microsatellites (SSR), can be used to estimate individuals’ pairwise relatedness, which is based on the probabilities’ ratios of the identity in state between the individuals compared and the reference unrelated population These estimates can be very useful to infer the level of relationship among sub-populations of elite material and/or for the design of controlled crosses between putatively unrelated parents. Using 113 putatively unrelated individuals - genotyped with 18 SSR - self, full-sib, half-sib and unrelated were simulated, and four pairwise similarity coefficients were tested: Queller & Goodnight 1989; Li et al. 1993; Ritland 1996, and Lynch & Ritland 1999. The Lynch & Ritland (1999) coefficient was selected (Figure 1), for it displayed a better adjustment with the expected level of relatedness and narrower standard errors (SE). SE were calculated through Monte- Carlo techniques, to avoid unequal sample size bias, by using 105 simulations for each relatedness group. To illustrate the usefulness of molecular estimates of similarity in genetic improvement programs, a clustering (UPGMA) based on the pairwise Lynch & Ritland (1999) coefficient (LR) values was performed to infer about the putative relationship among individuals of the subgroups of E. globulus elite individuals. From that analysis at least two pairs might be related and a PCA analysis confirmed the clustering results
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