890 resultados para effective utilization


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Pfs230, surface protein of gametocyte/gamete of the human malaria parasite, Plasmodium falciparum, is a prime candidate of malaria transmission-blocking vaccine. Plasmodium vivax has an ortholog of Pfs230 (Pvs230), however, there has been no study in any aspects on Pvs230 to date. To investigate whether Pvs230 can be a vivax malaria transmission-blocking vaccine, we performed evolutionary and population genetic analysis of the Pvs230 gene (pvs230: PVX_003905). Our analysis of Pvs230 and its orthologs in eight Plasmodium species revealed two distinctive parts: an interspecies variable part (IVP) containing species-specific oligopeptide repeats at the N-terminus and a 7.5 kb interspecies conserved part (ICP) containing 14 cysteine-rich domains. Pvs230 was closely related to its orthologs, Pks230 and Pcys230, in monkey malaria parasites. Analysis of 113 pvs230 sequences obtained from worldwide, showed that nucleotide diversity is remarkably low in the non-repeat 8-kb region of pvs230 (theta pi = 0.00118) with 77 polymorphic nucleotide sites, 40 of which results in amino acid replacements. A signature of purifying selection but not of balancing selection was seen on pvs230. Functional and/or structural constraints may limit the level of polymorphism in pvs230. The observed limited polymorphism in pvs230 should ground for utilization of Pvs230 as an effective transmission-blocking vaccine. (C) 2011 Elsevier Ltd. All rights reserved.

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We derive a closed form expression for the long wavelength limit of the effective action for hard thermal loops in an external gravitational field. It is a function of the metric, independent of time derivatives. It is compared and contrasted with the static limit, and with the corresponding limits in an external Yang-Mills field. (C) 2009 Elsevier B.V. All rights reserved.

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We present, from first principles, a direct method for evaluating the exact fermion propagator in the presence of a general background held at finite temperature, which can be used to determine the finite temperature effective action for the system. As applications, we determine the complete one loop finite temperature effective actions for (0 + 1)-dimensional QED as well as the Schwinger model. These effective actions, which are derived in the real time (closed time path) formalism, generate systematically all the Feynman amplitudes calculated in thermal perturbation theory and also show that the retarded (advanced) amplitudes vanish in these theories. (C) 2009 Elsevier B.V. All rights reserved.

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we study the one-loop quantum corrections for higher-derivative superfield theories, generalizing the approach for calculating the superfield effective potential. In particular, we calculate the effective potential for two versions of higher-derivative chiral superfield models. We point out that the equivalence of the higher-derivative theory for the chiral superfield and the one without higher derivatives but with an extended number of chiral superfields occurs only when the mass term is contained in the general Lagrangian. The presence of divergences can be taken as an indication of that equivalence. (C) 2009 Elsevier B.V. All rights reserved.

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We develop the superfield approach to the effective potential in three dimensions and calculate the one-loop and two-loop Kahlerian effective potential in commutative and noncommutative cases. (C) 2009 Published by Elsevier B.V.

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A systematic study was made of the synthesis of V(2)O(5)center dot nH(2)O nanostructures, whose morphologies, crystal structure, and amount of water molecules between the layered structures were regulated by strictly controlling the hydrothermal treatment variables. The synthesis involved a direct hydrothermal reaction between V(2)O(5) and H(2)O(2), without the addition of organic surfactant or inorganic ions. The experimental results indicate that high purity nanostructures can be obtained using this simple and clean synthetic route. Oil the basis of a study of hydrothermal treatment variables such as reaction temperature and time, X-ray diffraction (XRD) and scanning transmission electron microscopy (STEM) revealed that it was possible to obtain nanoribbons of the V(2)O(5)center dot nH(2)O monoclinic phase and nanowires or nanorods of the V(2)O(5)center dot nH(2)O orthorhombic phase. Thermal gravimetric analysis (TGA) shows also that the water content in the Structure call be controlled at appropriate hydrothermal conditions. Concerning the oxidation state of the vanadium atoms of as-obtained samples, a mixed-valence state composed of V(4+) and V(5+) was observed ill the V(2)O(5)center dot nH(2)O monoclinic phase, while the valence of the vanadium atoms was preferentially 5+ in the V(2)O(5)center dot nH(2)O orthorhombic phase. The X-ray absorption near-edge structure (XANES) results also indicated that the local structure of vanadium possessed a higher degree of symmetry in the V(2)O(5)center dot nH(2)O monoclinic phase.

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This study evaluated the process of ablation produced by a Ti:Sapphire femtosecond laser under different average powers taking place at the enamel/dentin interface. Based on the geometry of ablated microcavities the effective intensity for ablation was obtained. This study shows the validity for the local effective intensity analysis and allows a quantification of the variation in the ablation geometry taking place at the interface of two naturally different materials. It shows that the variation of the diameter of the ablated region as a function of the cavity depth comes essentially from a mechanism of effective intensity attenuation, as a result of a series of complex effects. Additionally, our data are sufficient to predict that a discontinuity on the ablation profile will occur on the interface between two biological media: enamel-dentin, showing a suddenly jump on the ablated cavity dimensions.

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This paper applies the concepts and methods of complex networks to the development of models and simulations of master-slave distributed real-time systems by introducing an upper bound in the allowable delivery time of the packets with computation results. Two representative interconnection models are taken into account: Uniformly random and scale free (Barabasi-Albert), including the presence of background traffic of packets. The obtained results include the identification of the uniformly random interconnectivity scheme as being largely more efficient than the scale-free counterpart. Also, increased latency tolerance of the application provides no help under congestion.

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We described herein the molecular design of novel in vivo anti-inflammatory 6-methanesulfonamide-3,4-methylenedioxyphenyl-N-acylhydrazone derivatives (1) planned by applying the molecular hybridization approach. This work also points out to the discovery of LASSBio-930 (1c) as a novel anti-inflammatory and anti-hyperalgesic prototype, which was able to reduce carrageenan-induced rat paw edema with an ED(50) of 97.8 mu mol/kg, acting mainly as a non-selective COX inhibitor. (C) 2009 Elsevier Ltd. All rights reserved.

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In this work, we deal with the problem of packing (orthogonally and without overlapping) identical rectangles in a rectangle. This problem appears in different logistics settings, such as the loading of boxes on pallets, the arrangements of pallets in trucks and the stowing of cargo in ships. We present a recursive partitioning approach combining improved versions of a recursive five-block heuristic and an L-approach for packing rectangles into larger rectangles and L-shaped pieces. The combined approach is able to rapidly find the optimal solutions of all instances of the pallet loading problem sets Cover I and II (more than 50 000 instances). It is also effective for solving the instances of problem set Cover III (almost 100 000 instances) and practical examples of a woodpulp stowage problem, if compared to other methods from the literature. Some theoretical results are also discussed and, based on them, efficient computer implementations are introduced. The computer implementation and the data sets are available for benchmarking purposes. Journal of the Operational Research Society (2010) 61, 306-320. doi: 10.1057/jors.2008.141 Published online 4 February 2009

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One of the key objectives in fuel-cell technology is to improve the performance of the anode catalyst for the alcohol oxidation and reduce Pt loading. Here, we show the use of six different electrocatalysts synthesized by the sol -gel method on carbon powder to promote the oxidation of methanol in acid media. The catalysts Pt-PbO(x) and Pt-(RuO(2)-PbO(x)) with 10% of catalyst load exhibited significantly enhanced catalytic activity toward the methanol oxidation reaction as compared to Pt-(RuO(2))/C and Pt/C electrodes. Cyclic voltammetry studies showed that the electrocatalysts Pt-PbO(x)/C and Pt-(RuO(2)-PbO(x))/C started the oxidation process at extremely low potentials and that they represent a good novelty to oxidize methanol. Furthermore, quasi-stationary polarization experiments and cronoamperometry studies showed the good performance of the Pt-PbO(x), Pt-(RuO(2)-PbO(x))/C and Pt-(RuO(2)-IrO(2))/C catalysts during the oxidation process. Thus, the addition of metallic Pt and PbO(x) onto high-area carbon powder, by the sol -gel route, constitutes an interesting way to prepare anodes with high catalytic activity for further applications in direct methanol fuel cell systems.

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Integration or illusion – a deviance perspective Denmark experienced one of its most successful periods of economic growth in 2004– 2008 with a tremendous reduction of unemployment, which in June 2008 was around. 1.5 percent, far below the expected level of structural unemployment. In the wake of this development the lack of utilization of migrants’ educations and skills became, once again, a core concern. The political, societal and academic debate followed to a great extent the traditional top-down approach to the problem and revolved around two axes: 1. How effective the labour market was/is to make use of migrants’ skills. 2. Whether there were patterns of over-education as expression of institutional and societal discrimination. The focus of the present study is, however, quite different: We examine the pattern of deviance in relation to labour market participation (not integration), and instead of searching for explanations for the lack of integration, we attempt to identify and explain the deviance pattern as a product of institutionally inherent possibilities and barriers on the one hand and articulating immigrants as rational actors (not victims) on the other. We argue that deviance is not only a more fruitful theoretical and analytical framework than integration and discrimination. Taking departure in empirical evidence on immigrants’ preferences and behaviour as bounded rational actors, and how they actually articulate their everyday life practical experiences, including adjustment of what they want and what they can, the deviance perspective, we believe, also reduces the theoretical and normative biases, that characterises the discrimination and integration framework, and provide more reliable explanations. 

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Background. Nurses' research utilization (RU) as part of evidence-based practice is strongly emphasized in today's nursing education and clinical practice. The primary aim of RU is to provide high-quality nursing care to patients. Data on newly graduated nurses' RU are scarce, but a predominance of low use has been reported in recent studies. Factors associated with nurses' RU have previously been identified among individual and organizational/contextual factors, but there is a lack of knowledge about how these factors, including educational ones, interact with each other and with RU, particularly in nurses during the first years after graduation. The purpose of this study was therefore to identify factors that predict the probability for low RU among registered nurses two years after graduation. Methods. Data were collected as part of the LANE study (Longitudinal Analysis of Nursing Education), a Swedish national survey of nursing students and registered nurses. Data on nurses' instrumental, conceptual, and persuasive RU were collected two years after graduation (2007, n = 845), together with data on work contextual factors. Data on individual and educational factors were collected in the first year (2002) and last term of education (2004). Guided by an analytic schedule, bivariate analyses, followed by logistic regression modeling, were applied. Results. Of the variables associated with RU in the bivariate analyses, six were found to be significantly related to low RU in the final logistic regression model: work in the psychiatric setting, role ambiguity, sufficient staffing, low work challenge, being male, and low student activity. Conclusions. A number of factors associated with nurses' low extent of RU two years postgraduation were found, most of them potentially modifiable. These findings illustrate the multitude of factors related to low RU extent and take their interrelationships into account. This knowledge might serve as useful input in planning future studies aiming to improve nurses', specifically newly graduated nurses', RU.