988 resultados para QQQQ(Q)OVER-BAR COMPONENTS


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Areanaeus cribrarius females were collected over a 12-month period with otter-trawl nets in the Ubatuba littoral zone, Brazil. Ovigerous individuals were measured (CW = carapace width excluding lateral spines) and weighed (WW = wet weight). Each egg brood was weighed (WE = wet weight), dried, and the number of eggs (EN) counted. Scatterplots from EN/CW, EN/WW, and EN/WE were submitted to regression analyses. Mean relative fecundity ((F) over bar') was calculated in each month/season to assess seasonal variation of reproductive intensity. The number of eggs showed a positive correlation with CW, WW, and WE. Fecundity of A. cribrarius ranged from 135,210 to 682,156 eggs, intermediate in comparison with other portunids. Fecundity in Portunidae is typically high; lower values are found in Polybiinae and higher ones in Portuninae. Mean fecundity did not reveal significant differences over months and seasons, but reproductive activity tended to be more intense in summer and winter, a phenomenon related to reduced temperature oscillations as found in subtropical regions.

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Introduction: The sport practiced by people with disabilities has been growing in recent years. Consequently, advances in assessment and training methods have emerged. However, the paralympic sport keeps in tow these advances, with few specific studies that consider disability as intervening factor. The transcranial direct current stimulation (tDCS) is a technique that has proven to be capable of modulating brain function. Studies show beneficial effects of tDCS on muscle strength, power and fatigue during exercise. Objective: Investigate de the effect of tDCS on movement control in para-powerlifters. Methods: Eight subjects underwent two sessions of motion capture, which previously applied the anodic tDCS or sham sessions in the cerebellum. Three movements were performed with increasing load between 90-95% of 1MR. The movements were recorded by an 10 infrared cameras system which reconstructed the 3D trajectory of markers placed on the bar. Results: There have been changes between the anodic and sham conditions over bar level (initial, final, maximum during the eccentric and concentric phase) and in the difference between the final and initial bar level. Moreover, there was difference in bar level (final and during the eccentric phase) comparing athletes amputees and les autres. Conclusion: The findings of this study suggest that tDCS applied prior to the exercise over the cerebellum in para-powerlifters acts differently according to disability

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The scheme is based on Ami Harten's ideas (Harten, 1994), the main tools coming from wavelet theory, in the framework of multiresolution analysis for cell averages. But instead of evolving cell averages on the finest uniform level, we propose to evolve just the cell averages on the grid determined by the significant wavelet coefficients. Typically, there are few cells in each time step, big cells on smooth regions, and smaller ones close to irregularities of the solution. For the numerical flux, we use a simple uniform central finite difference scheme, adapted to the size of each cell. If any of the required neighboring cell averages is not present, it is interpolated from coarser scales. But we switch to ENO scheme in the finest part of the grids. To show the feasibility and efficiency of the method, it is applied to a system arising in polymer-flooding of an oil reservoir. In terms of CPU time and memory requirements, it outperforms Harten's multiresolution algorithm.The proposed method applies to systems of conservation laws in 1Dpartial derivative(t)u(x, t) + partial derivative(x)f(u(x, t)) = 0, u(x, t) is an element of R-m. (1)In the spirit of finite volume methods, we shall consider the explicit schemeupsilon(mu)(n+1) = upsilon(mu)(n) - Deltat/hmu ((f) over bar (mu) - (f) over bar (mu)-) = [Dupsilon(n)](mu), (2)where mu is a point of an irregular grid Gamma, mu(-) is the left neighbor of A in Gamma, upsilon(mu)(n) approximate to 1/mu-mu(-) integral(mu-)(mu) u(x, t(n))dx are approximated cell averages of the solution, (f) over bar (mu) = (f) over bar (mu)(upsilon(n)) are the numerical fluxes, and D is the numerical evolution operator of the scheme.According to the definition of (f) over bar (mu), several schemes of this type have been proposed and successfully applied (LeVeque, 1990). Godunov, Lax-Wendroff, and ENO are some of the popular names. Godunov scheme resolves well the shocks, but accuracy (of first order) is poor in smooth regions. Lax-Wendroff is of second order, but produces dangerous oscillations close to shocks. ENO schemes are good alternatives, with high order and without serious oscillations. But the price is high computational cost.Ami Harten proposed in (Harten, 1994) a simple strategy to save expensive ENO flux calculations. The basic tools come from multiresolution analysis for cell averages on uniform grids, and the principle is that wavelet coefficients can be used for the characterization of local smoothness.. Typically, only few wavelet coefficients are significant. At the finest level, they indicate discontinuity points, where ENO numerical fluxes are computed exactly. Elsewhere, cheaper fluxes can be safely used, or just interpolated from coarser scales. Different applications of this principle have been explored by several authors, see for example (G-Muller and Muller, 1998).Our scheme also uses Ami Harten's ideas. But instead of evolving the cell averages on the finest uniform level, we propose to evolve the cell averages on sparse grids associated with the significant wavelet coefficients. This means that the total number of cells is small, with big cells in smooth regions and smaller ones close to irregularities. This task requires improved new tools, which are described next.

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In the present work, tellurite 20Li(2)O-80TeO(2) glasses were prepared with identical nominal composition under different glass-forming histories to produce a stressed and stress-free samples. X-ray Diffraction (XRD) and Differential Scanning Calorimetry (DSC) techniques were used to study the effects of the glass-forming histories on the thermal and structural properties of these glasses. The gamma-TeO2 (metastable), alpha-TeO2 and alpha-Li2Te2O5 phases were identified during the controlled devitrification in these glasses. The mestastable character of the gamma-TeO2 phase was clearly observed in the glass under stress but this effect is not so clear in the stress-free glass. The gamma-TeO2 and alpha-TeO2 phases crystallizes during the initial stages of crystallization in both studied glasses while the alpha-Li2Te2O5 phase crystallize in the final stages of the crystallization. The activation energies and Avrami exponent were calculated for both studied glasses with different particle size leading to E-3 > E-2 > E-1 for stressed glass and E-3 > E-2 approximate to E-1 for stress-free glass, where E-1, E-2 and E-3 were associated to the gamma-TeO2, alpha-TeO2 and alpha-Li2Te2O5 phases, respectively. The observed distinct (n) over bar (1) < <(n)over bar>(2) < <(n)over bar>(3) in both glasses is an indicative that nucleation and growth takes place by more than one mechanism in the early stages of the crystallization. (C) 2011 Elsevier B.V. All rights reserved.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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The mite Varroa destructor (Anderson & Treuman 2000) has caused extensive damage to beekeeping worldwide. In Brazil, weather conditions and the strains of bees do not provide ideal conditions for mite parasitism, which is reflected in the low number of deaths of colonies caused by varroatosis well as the stability of infestation levels. The aim of this study was to evaluate the damage caused by the mite infestation in hives maintained in natural conditions. For this purpose the number of mites per bee was calculated and used to quantify the level of infestation in each colony. To record the mortality rates of parasitized bees during development daily checks were performed. The data were analyzed by G test of independence and a Test of Proportions. The results indicate that the rate of mortality of pupae and larvae was proportional to the degree of infestation in each colony, and all colonies showed mortality rates significantly higher than the control rate. A significant interaction among death rates recorded between the third and fourth days of larval life and the total death of larvae was found (G Test = 50.22; P < 0.0001). So, it can be concluded that bee inbreeding contributed significantly to the increase of the larval rate of mortality. In Africanized honeybee colonies infested by the mite Varroa destructor mortality rates in conditions of natural infestation varied from 6.65 to 9.89% in pupae (<(x)over bar>= 8.78%) and from 6.13 to 13.48% in larvae ((x) over bar = 9.91%), against 3.85% and 3.74% in the control colony, respectively. Therefore, in the infested colonies the average rates of mortality caused by the harmful effects of the mite were, respectively, 2.28 times and 2.65 times greater in those two developmental stages.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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The J/psipi --> (D) over barD*, D (D) over bar*, (D) over bar *D* and (D) over barD cross sections as a function of roots are evaluated in a QCD sum rule calculation. We study the Borel sum rule for the four point function involving pseudoscalar and vector meson currents, up to dimension four in the operator product expansion. We find that our results are smaller than the J/psipi --> charmed mesons cross sections obtained with models based on meson exchange, but are close to those obtained with quark exchange models. (C) 2002 Elsevier B.V. B.V. All rights reserved.

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The H1 Collaboration recently reported a new analysis of data on the inelastic photoproduction of J/psi mesons at DESY's HERA ep collider. We show that these new experimental results are well described by the color evaporation model for quarkonium production. Moreover, these new data require the introduction of resolved photon contributions in order to accommodate the results in the kinematic region where the fractional energy carried by the J/psi is small, demonstrating that colored perturbative c (c) over bar states contribute to the production of a color singlet.

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Improving previous calculations, we compute the D + (D) over bar J/psi + pi cross section using the most complete effective Lagrangians available. The new crucial ingredients are the form factors on the charm meson vertices, which are determined from QCD sum rules calculations. Some of them became available only very recently, and the last one, needed for our present purpose, is calculated in this work.

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We consider a model with soft CP violation which accommodates the CP violation in the neutral kaons even if we assume that the Cabibbo-Kobayashi-Maskawa mixing matrix is real and the sources of CP violation are three complex vacuum expectation values and a trilinear coupling in the scalar potential. We show that for some reasonable values of the masses and other parameters the model allows us to explain all the observed CP violation processes in the K-0-(K) over bar (0) system.