Using parametric regressors to disentangle properties of multi-feature processes

FMRI data observed under a given experimental condition may be decomposed into two parts: the average effect and the deviation of single replications from this average effect. The average effect is represented by the mean activation over a specific condition. The deviation from this average effect may be decomposed into two components as well: systematic variation due to known empirical factors and pure measurement error. In most fMRI designs deviations from mean activation may be treated as measurement error. Nevertheless, often deviation from the average also may contain systematic variation that can be distinguished from simple measurement error. In these cases, the average fMRI signal may provide only a coarse picture of real brain activation. The larger the variation within-condition, the coarser the average effect and the more relevant is the impact of deviations from it. Systematic deviation from the mean activation may be examined by defining a set of parametric regressors. Here, the applicability of parametric methods to refine the evaluation of fMRI studies is discussed with special emphasis on (i) examination of the impact of continuous predictors on the fMRI signal, (ii) control for variation within each experimental condition and (iii) isolation of specific contributions by different features of a single complex stimulus, especially in the case of a sampled stimulus. The usefulness and applicability of this method are discussed and an example with real data is presented

Physical and mechanical properties of ZrO[2]/single wall carbon nanotubes nanocomposites

Zirconia ceramics reinforced with 0, 0.1, 0.5, and 1 wt.% single wall carbon nanotubes were fabricated by spark plasma sintering. The sintering was performed at 1500°C with a dwell time of 10 min, with heating and cooling rates of 100°C/min, and uniaxial pressure of 40 MPa was applied. Relative densities of the obtained pellets were calculated by weighing the pellets and measuring their dimensions. The highest value for microhardness was obtained for the pure ZrO[2] (14.72 GPa), and it decreased with the increase in the content of carbon nanotubes. On the other hand, fracture toughness of the obtained composites increased with the increase in carbon content. The highest value for fracture toughness was obtained for the composite with 1 wt.% of CNT (6.97 MPa·m{1/2})

Las Lunas, Yuncler (Toledo). Un depósito de materiales metálicos del Bronce Final en la Submeseta Sur de la Península Ibérica

Se exponen los resultados del primer estudio realizado sobre un nuevo conjunto de materiales metálicos del Bronce Final recuperado a finales de 2008 en las excavaciones arqueológicas del yacimiento de Las Lunas (Yuncler, Toledo, España). La localización geográfica del hallazgo, lejos de las principales zonas de dispersión conocidas para este tipo de conjuntos, la singularidad de los objetos que integra, y las relaciones atlánticas y mediterráneas que evidencian sus materiales, lo convierten en un ejemplo destacado para el estudio de este período en el centro de la Península Ibérica.Peer reviewe

The synthesis of a novel diazo-diphosphetidine-diamine based on interaction of 2-amino-4-phenylthiazole with chloride phosphorus(III)

In recent years, the obtaining and study of structural features of organophosphorus heterocyclic compounds with P-N bond, attracted considerable attention. Heterocycles which contain P-C, P-N, P-O and P-S bonds have a high biological activity and commercial importance. In this work, we have studied the reaction of interaction 2-amino-4-phenylthiazole with. phosphorus trichloride The conditions of reaction and structure of the resulting compounds were found

The gas–liquid phase-transition singularities in the framework of the liquid-state integral equation formalism

6 pages, 4 figures.-- PACS: 64.70.Fx; 65.20.+w; 02.30.Rz; 62.10.+sThe singularities of various liquid-state integral equations derived from the Ornstein–Zernike relation and its temperature derivatives, have been investigated in the liquid–vapor transition region. As a general feature, it has been found that the existence of a nonsolution curve on the vapor side of the phase diagram, on which both the direct and the total correlation functions become complex—with a finite isothermal compressibility—also corresponds to the locus of points where the constant-volume heat capacity diverges, in consonance with a divergence of the temperature derivative of the correlation functions. In contrast, on the liquid side of the phase diagram one finds that a true spinodal (a curve of diverging isothermal compressibilities) is reproduced by the Percus–Yevick and Martynov–Sarkisov integral equations, but now this curve corresponds to states with finite heat capacity. On the other hand, the hypernetted chain approximation exhibits a nonsolution curve with finite compressibilities and heat capacities in which, as temperature is lowered, the former tends to diverge.E.L. acknowledges financial support of the Dirección General de Investigación Científica y Técnica under Grant No. FIS2004-02954-C03-01. This work has been carried out under the auspices of the exchange agreement between the Consejo Superior de Investigaciones Científicas and the Russian Academy of Sciencies, which supported the exchange visits of E.L. and G.S. in the past two years.Peer reviewe