92 research outputs found
Avaliação da germinação de sementes de capim-annoni-2 submetido a diferentes níveis de sombreamento.
O capim-annoni-2 (Eragrostis plana Ness) é uma planta perene da família das gramíneas, considerada uma invasora agressiva de pastagens na região sul do Brasil com alta produção de sementes que conservam o poder germinativo por vários anos no solo.Número especial. Trabalho 1122. Edição dos Resumos do 19º Congresso Brasileiro de Sementes, Foz do Iguaçu, set. 2015
Structural Basis for the Aminoacid Composition of Proteins from Halophilic Archea
In order to survive in highly saline environments, proteins from halophilic archea have evolved with biased amino acid compositions that have the capacity to reduce contacts with the solvent
Three Stages of Lysozyme Thermal Stabilization by High and Medium Charge Density Anions
Addition of high and medium charge density anions (phosphate, sulfate, and chloride) to lysozyme in pure water demonstrates three stages for stabilization of the protein structure. The first two stages have a minor impact on lysozyme stability and are probably associated with direct interaction of the ions with charged and partial charges on the protein’s surface. There is a clear transition between the second and third stages; in the case of sodium chloride, disodium sulfate and disodium hydrogen phosphate this is at 550, 210, and 120 mM, respectively. Stabilization of lysozyme can be explained by the free energy required to hydrate the protein as it unfolds. At low ion concentrations, the protein’s hydration layer is at equilibrium with the bulk water. After the transition, bulk water is depleted and the protein is competing for water with the ions. With competition for water between the protein and the ions at higher salt concentrations, the free energy required to hydrate the interior of the protein rises and it is this that stabilizes the protein structure
Eco-efficiency measurement and material balance principle:an application in power plants Malmquist Luenberger Index
Incorporating Material Balance Principle (MBP) in industrial and agricultural performance measurement systems with pollutant factors has been on the rise in recent years. Many conventional methods of performance measurement have proven incompatible with the material flow conditions. This study will address the issue of eco-efficiency measurement adjusted for pollution, taking into account materials flow conditions and the MBP requirements, in order to provide ‘real’ measures of performance that can serve as guides when making policies. We develop a new approach by integrating slacks-based measure to enhance the Malmquist Luenberger Index by a material balance condition that reflects the conservation of matter. This model is compared with a similar model, which incorporates MBP using the trade-off approach to measure productivity and eco-efficiency trends of power plants. Results reveal similar findings for both models substantiating robustness and applicability of the proposed model in this paper
The Peripheral Binding of 14-3-3γ to Membranes Involves Isoform-Specific Histidine Residues
Mammalian 14-3-3 protein scaffolds include seven conserved isoforms that bind numerous phosphorylated protein partners and regulate many cellular processes. Some 14-3-3-isoforms, notably γ, have elevated affinity for membranes, which might contribute to modulate the subcellular localization of the partners and substantiate the importance of investigating molecular mechanisms of membrane interaction. By applying surface plasmon resonance we here show that the binding to phospholipid bilayers is stimulated when 14-3-3γ is complexed with its partner, a peptide corresponding to the Ser19-phosphorylated N-terminal region of tyrosine hydroxylase. Moreover, membrane interaction is dependent on salts of kosmotropic ions, which also stabilize 14-3-3γ. Electrostatic analysis of available crystal structures of γ and of the non-membrane-binding ζ-isoform, complemented with molecular dynamics simulations, indicate that the electrostatic potential distribution of phosphopeptide-bound 14-3-3γ is optimal for interaction with the membrane through amphipathic helices at the N-terminal dimerization region. In addition, His158, and especially His195, both specific to 14-3-3γ and located at the convex lateral side, appeared to be pivotal for the ligand induced membrane interaction, as corroborated by site-directed mutagenesis. The participation of these histidine residues might be associated to their increased protonation upon membrane binding. Overall, these results reveal membrane-targeting motifs and give insights on mechanisms that furnish the 14-3-3γ scaffold with the capacity for tuned shuffling from soluble to membrane-bound states.This work was supported by grants from the Norwegian Cancer Society (to ØH), Junta de Andalucía, grant CVI-02483 (to JMSR), The Research Council of Norway (grant 185181 to A.M.), the Western Norway Health Authorities (grant 911618 to A.M.) and The Kristian Gerhard Jebsen Foundation (to AM)
Assessment of the Performance of Osmotically Driven Polymeric Membrane Processes
The universal water scarceness and the extensive ordeals with energy cost in
conjunction with the undesirable ecological effects have advanced the
improvement of novel osmotically driven membrane processes. Membrane
processes which are osmotically driven are developing type of membrane
separation procedures that apply concentrated brines to separate liquid
streams. They are adaptable in various applications; hence, allow them to be
an attractive substitute for drug release, wastewater treatment and the
production and recovery of energy. Although, internal concentration
polarization (ICP) occurs in membrane practises which are osmotically driven
as a consequence of hindered diffusion of solute in a porous stratum, their
interest has even increased. Here we review two natural membrane processes
that are osmotically driven; Forward osmosis (FO) and Pressure retarded
osmosis (PRO). Thus, the major points are as follows: 1) it was highlighted in
this review, that the major developments in FO process, important for the
process efficiency is to choose a suitable membrane and draw solution. 2) The
recent evaluation, understanding and optimizing the activities of fouling
throughout the osmotic dilution of seawater employing FO was discussed. 3)
Recent advancements of FO in the application of food processing was
reviewed. 4) It was highlighted that the main concept of PRO for power
generation is the energy of mixing that offers great assessment of the nonexpansion
work which could be generated from mixing; nonetheless, the
development of effective membranes with appropriate arrangement and
performance is needed for the advancement of PRO process for power
generation. 5) One major challenge of osmotically driven membrane
processes, most recent developments and model development to predict their
performances were discussed
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