Avaliação do crescimento de espécies florestais por grupo ecológico em áreas exploradas na Flona do Tapajós.

III ENAAg

Ambient magnetic field amplification in shock fronts of relativistic jets: an application to GRB afterglows

Strong downstream magnetic fields of order of $\sim 1$G, with large correlation lengths, are believed to cause the large synchrotron emission at the afterglow phase of gamma ray bursts (GRBs). Despite of the recent theoretical efforts, models have failed to fully explain the amplification of the magnetic field, particularly in a matter dominated scenario. We revisit the problem by considering the synchrotron emission to occur at the expanding shock front of a weakly magnetized relativistic jet over a magnetized surrounding medium. Analytical estimates and a number of high resolution 2D relativistic magneto-hydrodynamical (RMHD) simulations are provided. Jet opening angles of $\theta = 0^{\circ} - 20^{\circ}$, and ambient to jet density ratios of $10^{-4} - 10^2$ were considered. We found that most of the amplification is due to compression of the ambient magnetic field at the contact discontinuity between the reverse and forward shocks at the jet head, with substantial pile-up of the magnetic field lines as the jet propagates sweeping the ambient field lines. The pile-up is maximum for $\theta \rightarrow 0$, decreasing with $\theta$, but larger than in the spherical blast problem. Values obtained for certain models are able to explain the observed intensities. The maximum correlation lengths found for such strong fields is of $l_{\rm corr} \leq 10^{14}$ cm, $2 - 6$ orders of magnitude larger than the found in previous works.Comment: mnras accepte

Diversidade genética de bovinos de corte por meio de marcadores microssatélites.

Uma alternativa para atender a demanda do mercado por carne de qualidade é a utilização de cruzamentos entre raças zebuínas e taurinas adaptadas. Assim, as raças Bonsmara, Caracu e Senepol (taurinas adaptadas), Angus (taurina não-adaptada) e Nelore (zebuína) foram analisadas utilizando cinco marcadores microssatélites para avaliar a diversidade genética existente dentro e entre as raças e orientar a sua utilização em cruzamentos. Foram analisados 127 touros Bonsmara, Caracu, Senepol, Angus e Nelore e as frequências alélicas foram utilizadas para estimar diversidade gênica, conteúdo de polimorfismo informativo, probabilidade de exclusão e uma matriz de distância genética Euc1ideana. Considerando a média das distâncias Euclideanas, calculadas individualmente para cada marcador, a maior distância genética foi observada entre as raças Angus e Nelore (0,62) e as menores entre Caracu e as demais raças taurinas adaptadas (0,41 e 0,35 para Bonsmara e Senepol, respectivamente). Entre as taurinas adaptadas, a Bonsmara foi a que apresentou a menor distância em relação ao Angus (0,50) e a maior em relação ao Nelore (0,59). A raça Caracu apresentou distância intermediária para Angus (0,53) e Nelore (0,55). As raças Bonsmara e Caracu apresentaram distância genética, em média, 8,3% maior que a raça Senepol para matrizes Angus X Nelore, proporcionando uma expectativa de maior heterose quando cruzadas com estas matrizes

A biorefinery from Nannochloropsis sp. microalga – Energy and CO2 emission and economic analyses

Are microalgae a potential energy source for biofuel production? This paper presents the laboratory results from a Nannochloropsis sp. microalga biorefinery for the production of oil, high-value pigments, and biohydrogen (bioH2). The energy consumption and CO2 emissions involved in the whole process (microalgae cultivation, harvest, dewater, mill, extraction and leftover biomass fermentation) were evaluated. An economic evaluation was also performed. Oil was obtained by soxhlet (SE) and supercritical fluid extraction (SFE). The bioH2 was produced by fermentation of the leftover biomass. The oil production pathway by SE shows the lowest value of energy consumption, 177-245 MJ/MJprod, and CO2 emissions, 13–15 kgCO2/MJprod. Despite consuming and emitting c.a. 20% more than the SE pathway, the oil obtained by SFE, proved to be more economically viable, with a cost of 365€/kgoil produced and simultaneously extracting high-value pigments. The bioH2 as co-product may be advantageous in terms of product yield or profit

Phenotyping the ideotypes of two maize landraces from Madeira archipelago using morpho-agronomic traits and zein pattern

Madeira Archipelago holds specific maize genetic resources whose populations, representing field diversity, were previously classified into four main landrace groups. The ISOPs 0061 and 0070, with common names of “Milho Sequeiro” and “Milho Branco” yellow and white maize, respectively, represent the ideotypes of two of these landraces. These ideotypes have now been analyzed using morpho-agronomic and biochemical traits, to phenotype these landraces. The variation of nine of the ten morpho-agronomic traits was used to separate the landraces ideotypes. However, the seven traits of seed biochemical composition did not allow to segregate the landraces ideotypes. This is not the case of zein pattern, which polymorphism shows to be specific for each ideotype. The original ideotypes populations were regenerated twice under low input conditions. Zein patterns of the original and regenerated accessions were compared, using two electrophoresis techniques. The lab-on-a-chip electrophoresis showed that the standard SDS-PAGE zein pattern with six fractions could be separated into eighteen (ISOP 0061) and twenty (ISOP 0070) protein bands. In contrast, no significant changes were detected in the zein pattern structure of the initial and regenerated accessions of both landraces ideotypes. The chip electrophoresis showed to be a suitable technique to screen and characterize a large number of individuals and accessions of the germplasm collections, due to its reproducibility. In particular, the zein patterns can be used to phenotype ideotypes and establish a formula representing their structure, allowing to detect changes in landrace structure, occurring as a result of gene bank management actions.info:eu-repo/semantics/publishedVersio

Urinary Estrogen Metabolites and Self-Reported Infertility in Women Infected with Schistosoma haematobium

Schistosomiasis is a neglected tropical disease, endemic in 76 countries, that afflicts more than 240 million people. The impact of schistosomiasis on infertility may be underestimated according to recent literature. Extracts of Schistosoma haematobium include estrogen-like metabolites termed catechol-estrogens that down regulate estrogen receptors alpha and beta in estrogen responsive cells. In addition, schistosome derived catechol-estrogens induce genotoxicity that result in estrogen-DNA adducts. These catechol estrogens and the catechol-estrogen-DNA adducts can be isolated from sera of people infected with S. haematobium. The aim of this study was to study infertility in females infected with S. haematobium and its association with the presence of schistosome-derived catechol-estrogens