47 research outputs found

    Sheep Performance in Italian Ryegrass Swards at Contrasting Sward Heights

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    The objective of this study was to assess the effect of Italian ryegrass (Lolium multiflorum Lam.) sward height on lamb performance. The experiment was carried out at the Research Station of UFRGS, Eldorado do Sul, Brazil. Yearling no-castrated male lambs were assessed in terms of individual animal performance and gain per hectare. The experiment was carried out in a randomised block design with three replications of four treatments: 5, 10, 15 and 20 cm of sward surface height (SSH), which were maintained using continuous variable stocking, and monitored by a sward stick. Samples of 0.25 m2 were cut to ground level to estimate herbage and leaf lamina mass. Live weight gain per area and per animal increased in a quadratic pattern. The best animal production was found in a sward of approximately 15 cm high

    Facile synthesis, structure, and battery-type behavior of graphene oxides

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    Abstract Graphene oxide (GO) is one of the main precursors for the production of graphene and other graphene-based materials. We report a simple, safe, and fast synthesis method to obtain graphene oxide as a functional material for battery-type electrodes. Washing and lyophilization processes were performed to evaluate their effects on exfoliation and removal of functional groups from graphene sheets. Sample GO1 consisted of a 10-layer stack of oxidized graphene, while sample GO2 had 8 stacked layers. The difference between them was an extra washing and lyophilization process in the GO2 sample. The electrochemical performance of graphene oxide-based electrodes, classified as battery-type, indicated an improved specific capacity of 10.15 C.g-1 for GO1 against 4.55 C.g-1 for GO2 at a specific current of 0.5 A.g-1. This superior battery-type behavior of the GO1 electrode, also confirmed by electrochemical impedance spectroscopy, was most likely due to a higher degree of oxygenated groups on its surface, as shown by energy dispersive spectroscopy (EDS) and Fourier transform infrared spectroscopy (FTIR) studies

    Evolutionary view of acyl-CoA diacylglycerol acyltransferase (DGAT), a key enzyme in neutral lipid biosynthesis

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    <p>Abstract</p> <p>Background</p> <p>Triacylglycerides (TAGs) are a class of neutral lipids that represent the most important storage form of energy for eukaryotic cells. DGAT (acyl-CoA: diacylglycerol acyltransferase; EC 2.3.1.20) is a transmembrane enzyme that acts in the final and committed step of TAG synthesis, and it has been proposed to be the rate-limiting enzyme in plant storage lipid accumulation. In fact, two different enzymes identified in several eukaryotic species, DGAT1 and DGAT2, are the main enzymes responsible for TAG synthesis. These enzymes do not share high DNA or protein sequence similarities, and it has been suggested that they play non-redundant roles in different tissues and in some species in TAG synthesis. Despite a number of previous studies on the DGAT1 and DGAT2 genes, which have emphasized their importance as potential obesity treatment targets to increase triacylglycerol accumulation, little is known about their evolutionary timeline in eukaryotes. The goal of this study was to examine the evolutionary relationship of the DGAT1 and DGAT2 genes across eukaryotic organisms in order to infer their origin.</p> <p>Results</p> <p>We have conducted a broad survey of fully sequenced genomes, including representatives of Amoebozoa, yeasts, fungi, algae, musses, plants, vertebrate and invertebrate species, for the presence of DGAT1 and DGAT2 gene homologs. We found that the DGAT1 and DGAT2 genes are nearly ubiquitous in eukaryotes and are readily identifiable in all the major eukaryotic groups and genomes examined. Phylogenetic analyses of the DGAT1 and DGAT2 amino acid sequences revealed evolutionary partitioning of the DGAT protein family into two major DGAT1 and DGAT2 clades. Protein secondary structure and hydrophobic-transmembrane analysis also showed differences between these enzymes. The analysis also revealed that the MGAT2 and AWAT genes may have arisen from DGAT2 duplication events.</p> <p>Conclusions</p> <p>In this study, we identified several DGAT1 and DGAT2 homologs in eukaryote taxa. Overall, the data show that DGAT1 and DGAT2 are present in most eukaryotic organisms and belong to two different gene families. The phylogenetic and evolutionary analyses revealed that DGAT1 and DGAT2 evolved separately, with functional convergence, despite their wide molecular and structural divergence.</p
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