421 research outputs found
Estimativa do parentesco numa população de melhoramento de Eucalyptus globulus através de microsatélites nucleares
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
indivÃduos e 16 microssatélites, da população base ou de referência (PR) de Eucalyptus
globulus do RAIZ. Através da recombinação gamética in silico foram simulados 105
indivÃduos com diferentes graus de parentesco: descendentes de autopolinização, meiosirmãos,
irmãos completos e indivÃduos 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 crÃtico correspondente à intercepção das funções densidade
dos indivÃduos não aparentados e dos meios-irmãos. O estimador escolhido foi aplicado Ã
PR. Detectaram-se 4,4% de pares de indivÃduos 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
indivÃduos deverão ser evitados
Tourism And Urbanization: Environmental Problem Of The Araruai Lagoon, State Of Rio De Janeiro, Brazil
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 comestÃveis: mistura de extratos fenólicos e polissacarÃdicos de Boletus edulis e Marasmius oreades.
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 quÃmicos e bioquÃmicos, sendo ainda determinados os fenóis totais (extratos fenólicos) e o teor em polissacáridos (extratos polissacarÃdicos). 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 quÃmicas 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 polissacarÃdicos 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
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
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
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
Influence de l'effeuillage sur l'efficience thermique de l'accumulation des anthocyanes dans la baie
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
Scattering from supramacromolecular structures
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
Rods Near Curved Surfaces and in Curved Boxes
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
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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