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We have investigated SiC layers produced by ion beam synthesis on Si(111) substrates using different procedures. Bare Si(111) and SiO2/Si(111) structures were implanted with carbon at 40 keV up to a fluence of 4×1017 cm-2 at a temperature of 600 °C. Postimplantation annealing was carried out at 1250 °C for 2 h in pure O2 or Ar (with 1% of O2). A SiC layer was synthesized for all the procedures involving annealing under Ar. However, for the samples annealed under pure O2 flux, only that employing implantation into the bare Si(111) resulted in SiC synthesis. Rutherford backscattering spectrometry shows that, after annealing, the stoichiometric composition is obtained. Transmission electron microscopy measurements demonstrate the synthesis of cubic-SiC layers that are completely epitaxial to the Si(111) substrate. However, there is a high density of nanometric twins, stacking faults, and also narrow amorphous inclusions of laminar shape between the crystalline regions. The procedure based on high temperature implantation through a SiO2 cap, etching the cap off, 1250 °C postimplantation annealing under Ar ambient (with 1% of O2), and final etching has shown advantages from the point of view of surface flatness and increased layer thickness, keeping the same layer epitaxy and accurate composition. [ABSTRACT FROM AUTHOR]

We present a method to solve constrained convex stochastic optimization problems when the objective is a finite sum of convex functions. Our method is based on Incremental Stochastic Subgradient Algorithms and String-Averaging techniques, with an assumption that the subgradient directions are affected by random errors in each iteration. Our analysis allows the method to perform approximate projections onto the feasible set in each iteration. We provide convergence results for the case where a diminishing step-size rule is used. We test our method in a large set of random instances of a stochastic convex programming problem and we compare its performance with the robust mirror descent stochastic approximation algorithm proposed in Nemirovski et al. (Robust stochastic approximation approach to stochastic programming, SIAM J Optim 19 (2009), pp. 15741609). [ABSTRACT FROM AUTHOR]

Copyright of Ceramica is the property of Associacao Brasileira de Ceramica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The objective of this research was to evaluate the organizational support for learning and the impact of the Course on Improvement in Public Management in the perception of the Technical-Administrative managers in Education of a public institution of education, science and technology of the Northeast of Brazil. It is a qualitative research, with a mode of investigation in the case study and a descriptive objective. For the data collection it was used a structured interview through the ISAM (Integrated and Summative Assessment Model), proposed by Jairo Borges-Andrade, Jardim Abbad and Luciana Mourão. The data collected were processed in electronic spreadsheets and the results show that: in terms of organizational support, there were favorable organizational conditions and there was commitment of the organization to the learning of the new skills of the workers, as well as the absorption by the individuals / work groups about how much the organization values its contributions of new knowledge. As for the impact of the training, it has been verified that there were improvements in the individual performance of the trained servants through a new way of performing old tasks from the new skills acquired. [ABSTRACT FROM AUTHOR]

Copyright of Ceramica is the property of Associacao Brasileira de Ceramica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Hepatitis E virus ( HEV) is a zoonotic agent today considered a major Public Health issue in industrialized countries. HEV strains belonging to zoonotic genotype 3 are widely present in swine, being today considered important reservoirs for human disease. Unlike in swine, only scarce data are available on the circulation of HEV in wild boar. This study describes the detection and molecular characterization of HEV in livers from sylvatic wild boar hunted in Portugal and destined for consumption. Additionally, the detection of HEV in stools of a confined wild boar population also destined for consumption is also described. A total of 80 liver samples collected during the hunting season of 2011/2012 and 40 stools collected in February 2012 from a wild boar breeding farm in Portugal were tested by a nested broad-spectrum RT- PCR assay targeting open reading frame ( ORF) 1. Twenty livers (25.0%) and 4 stools (10%) were positive for HEV. Phylogenetic analysis showed that all strains clustered with sequences classified as HEV genotype 3 subgenotype e. To our knowledge, this is the first report documenting the occurrence and molecular analysis of HEV in sylvatic and captive wild boar destined for human consumption in Portugal. This report demonstrates for the first time the circulation of HEV in wildlife reservoirs of Portugal adding knowledge to the epidemiology of HEV in wild boar populations. [ABSTRACT FROM AUTHOR]

Copyright of Ceramica is the property of Associacao Brasileira de Ceramica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Archivos de Zootecnia is the property of Archivos de Zootecnia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Direct numerical simulations of the variable density and viscosity Navier–Stokes equations are employed, in order to explore three-dimensional effects within miscible displacements in horizontal Hele-Shaw cells. These simulations identify a number of mechanisms concerning the interaction of viscous fingering with a spanwise Rayleigh–Taylor instability. The dominant wavelength of the Rayleigh–Taylor instability along the upper, gravitationally unstable side of the interface generally is shorter than that of the fingering instability. This results in the formation of plumes of the more viscous resident fluid not only in between neighbouring viscous fingers, but also along the centre of fingers, thereby destroying their shoulders and splitting them longitudinally. The streamwise vorticity dipoles forming as a result of the spanwise Rayleigh–Taylor instability place viscous resident fluid in between regions of less viscous, injected fluid, thereby resulting in the formation of gapwise vorticity via the traditional, gap-averaged viscous fingering mechanism. This leads to a strong spatial correlation of both vorticity components. For stronger density contrasts, the streamwise vorticity component increases, while the gapwise component is reduced, thus indicating a transition from viscously dominated to gravitationally dominated displacements. Gap-averaged, time-dependent concentration profiles show that variable density displacement fronts propagate more slowly than their constant density counterparts. This indicates that the gravitational mixing results in a more complete expulsion of the resident fluid from the Hele-Shaw cell. This observation may be of interest in the context of enhanced oil recovery or carbon sequestration applications. [ABSTRACT FROM PUBLISHER]

In this work nickelate nanoparticles were synthesized using a simple and fast new route, which makes use of gelatin as an organic precursor in order to evaluate the performance of the synthesis method to obtain materials and the influence of the strontium replacement on the structural parameters of the powders. Samples of Nd2-xSrxNiO4 (x = 0 and 0.4) were calcined at 700 and 900 °C at a heating of 10 °C/min for 4 hours. X-ray powder diffraction patterns were obtained for all the samples, and the Rietveld Method was applied in order to determine the crystallite size using Scherrer's equation, the lattice parameters, and phase concentration. The results obtained using these techniques confirmed that the main crystal structure consists of the distorted K2NiF4-type tetragonal I4/mmm. In addition, scanning electron microscopy images revealed the formation of nanosized particles. [ABSTRACT FROM AUTHOR]

An increase in immigration from endemic regions has resulted in a number of cases of paracoccidioidomycosis (PCM) being imported into Spain. A molecular diagnostic technique based on real-time PCR was developed for the detection of Paracoccidioides brasiliensis DNA in both culture and patients’ clinical samples. A Molecular Beacon probe was used, labelled with FAM and directed at the ITS1 region of ribosomic DNA. The detection limit of the technique developed was 1 fg of fungal DNA per µl of sample. This procedure proved to be very reproducible and specific. The technique was tested with cultures of 12 clinical strains and on samples from two patients with proven PCM. Real-time PCR was positive for all the culture strains, as well as those from both patients. By samples, the technique was positive in sputum and tissue biopsies but less useful on blood samples. Samples were analyzed several months after patient treatment, detecting a small amount of fungal DNA in one respiratory sample. This technique of real-time PCR is a sensitive method for rapid diagnosis of paracoccidioidomycosis and could serve to monitor patients after treatment has begun. [ABSTRACT FROM AUTHOR]

Among the Opiliones, species of the suborders Cyphophthalmi, Eupnoi, Dyspnoi and Laniatores have shown very diverse diploid chromosome numbers. However, only certain Eupnoi species exhibit XY/XX and ZZ/ZW sex chromosome systems. Considering the scarcity of karyotypical information and the absence of structurally identifiable sex chromosomes in the suborder Laniatores, we decided to analyse the chromosomes and bivalents of Discocyrtus pectinifemur (Gonyleptidae) to identify possible sex differences. Testicular cells examined under light microscopy showed a high diploid number, 2 n = 88, meta/submetacentric chromosome morphology and a nucleolar organizer region on pair 35. Prophase I microspreading observed in transmission electron microscopy exhibited 44 synaptonemal complexes with similar electron density and thickness. The total and regular synapsis between the chromosomes of the bivalents was also noted in pachytene nuclei. Male mitotic and meiotic chromosomes revealed no distinct characteristic that could be related to the occurrence of heteromorphic sex chromosomes. Evolutionary trends of chromosome differentiation in the four suborders of Opiliones are discussed here. [ABSTRACT FROM AUTHOR]

The close relationship between the behavior of the edge plasma characteristics and the global confinement in discharges in tokamaks has been extensively explored in recent years. A 15 keV lithium beam with 80% neutralization efficiency, using a high ion current density emitter and a modified Pierce gun design for extraction of ions, was developed for edge studies on the spherical tokamak ETE—(major radius R=0.30 m, aspect ration A=1.5, designed plasma current of 200 kA with a torodial magnetic field up to 0.4 T). Already in the calibration phase this diagnostics confirmed to be an efficient experimental tool, allowing accurate measurements of the fast varying pressure of the discharges in ETE. The measurement of the temporal evolution of the density of the plasma edge with fast neutral lithium beam is in accordance with data from Langmuir probe for the region near the limiter and the one made by the Thomson scattering for the inner region. [ABSTRACT FROM AUTHOR]

New designs for Magnetic Resonance Imaging contrast agents are presented. Essentially, they all are host–guest inclusion complexes between γ-cyclodextrins and polyazamacrocycles of gadolinium (III) ion. Substitutions have been made to the host to optimise the host–guest association. Molecular mechanics calculations have been performed, using the UFF force field for metals, to decide on the suitability of the substitutions, and to evaluate the host–guest energies of association. Interesting general conclusions have been obtained, concerning the improvement of Magnetic Resonance Imaging contrast agents; namely, a set of rational methodologies have been deduced to improve the association between the gadolinium (III) chelates and the cyclodextrins, and their efficiency is demonstrated with a large set of substituted complexes, opening new doors to increase the diagnostic capabilities of Magnetic Resonance Imaging. [ABSTRACT FROM AUTHOR]

A 10 J ruby laser Thomson scattering system was implemented on the ETE spherical tokamak to measure the density n[sub e] and temperature T[sub e] profiles. The laser probes the plasma at the horizontal midplane of the torus and the collection optics allows the observation of up to 22 points inside the plasma in the same plane. Radial profiles of plasma density and electron temperature were obtained for different times during the discharge by shot-to-shot procedure. Temperatures of up to 160 eV and densities of 2.2 × 10[sup 19] m[sup -3] were measured. Since the level of stray light was too high, the calibration of the Thomson scattering system for density measurements was made using the nitrogen Raman technique instead of the usually applied Rayleigh method. [ABSTRACT FROM AUTHOR]