16,350 research outputs found

    Changing the face of consulting: the women's initiative at Deloitte

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    Deloitte & Touche was hiring the best and brightest men and women, and proportionately losing 80 percent of the women before they reached partner level.Sex discrimination against women ; Women executives

    Experimental assessment and retrofit of full-scale models of existing RC frames

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    PSD tests on two full-scale models of existing non-seismic resisting RC frame structures are described. The testing program covered several aspects, namely assessment of seismic performance of existing frames without and with infill panels, retrofitting of the bare frame using Selective Retrofitting techniques, strengthening of the infill panels using shotcrete and retrofitting of the frame using K-bracing with shear-link dissipators. The main results from the tests are summarized and discussed and the conclusions are drawn. The tests on the bare frame have shown how vulnerable are existing structures constructed in the 60’s and the beneficial effects of infill panels were confirmed from the tests on the infilled frame. Important improvements, in terms of seismic performance, were achieved by the retrofitting of the frames. However, it was also confirmed that strengthening of the existing infill panels in poorly detailed frames may lead to dangerous ‘local’ failures, such as the shear out of the external columns

    A venting alarm system for cryogenic liquids

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    Alarm system for cryogenic fluid storage tank

    Vortex evolution in parametric wave mixing

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    We investigate the evolution of vortex wave front dislocations in multiple-wave second-harmonic generation processes in quadratic nonlinear media. Vortices nested in finite-size host beams are shown to nucleate and to annihilate in pairs, and to move across the transverse wave front during the beam evolution. A closed-form model that holds under conditions of negligible-depletion of the pump beam is developed to describe the vortex dynamics in order to predict the number of vortices present in the wave fronts of the beams at any instance of the propagation. Results are compared with numerical simulations of the full governing equations and with experimental observations. Limitations of the model are outlined.Peer ReviewedPostprint (published version

    Bacterial Active Community Cycling in Response to Solar Radiation and Their Influence on Nutrient Changes in a High-Altitude Wetland

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    Indexación: Web of Science; Scopus.Microbial communities inhabiting high-altitude spring ecosystems are subjected to extreme changes in solar irradiance and temperature throughout the diel cycle. Here, using 16S rRNA gene tag pyrosequencing (cDNA) we determined the composition of actively transcribing bacteria from spring waters experimentally exposed through the day (morning, noon, and afternoon) to variable levels of solar radiation and light quality, and evaluated their influence on nutrient recycling. Solar irradiance, temperature, and changes in nutrient dynamics were associated with changes in the active bacterial community structure, predominantly by Cyanobacteria, Verrucomicrobia, Proteobacteria, and 35 other Phyla, including the recently described Candidate Phyla Radiation (e.g., Parcubacteria, Gracilibacteria, OP3, TM6, SR1). Diversity increased at noon, when the highest irradiances were measured (3.3-3.9 H', 1125 W m(-2)) compared to morning and afternoon (0.6-2.8 H'). This shift was associated with a decrease in the contribution to pyrolibraries by Cyanobacteria and an increase of Proteobacteria and other initially low frequently and rare bacteria phyla (< 0.5%) in the pyrolibraries. A potential increase in the activity of Cyanobacteria and other phototrophic groups, e.g., Rhodobacterales, was observed and associated with UVR, suggesting the presence of photo activated repair mechanisms to resist high levels of solar radiation. In addition, the percentage contribution of cyanobacterial sequences in the afternoon was similar to those recorded in the morning. The shifts in the contribution by Cyanobacteria also influenced the rate of change in nitrate, nitrite, and phosphate, highlighted by a high level of nitrate accumulation during hours of high radiation and temperature associated with nitrifying bacteria activity. We did not detect ammonia or nitrite oxidizing bacteria in situ, but both functional groups (Nitrosomona and Nitrospira) appeared mainly in pyrolibraries generated from dark incubations. In total, our results reveal that both the structure and the diversity of the active bacteria community was extremely dynamic through the day, and showed marked shifts in composition that influenced nutrient recycling, highlighting how abiotic variation affects potential ecosystem functioning.http://journal.frontiersin.org/article/10.3389/fmicb.2016.01823/ful

    Cognitive outcome and gamma noise power unrelated to neuregulin 1 and 3 variation in schizophrenia

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    Background Neuregulins are a family of signalling proteins that orchestrate a broad range of cellular responses. Four genes encoding Neuregulins 1–4 have been identified so far in vertebrates. Among them, Neuregulin 1 and Neuregulin 3 have been reported to contribute to an increased risk for developing schizophrenia. We hypothesized that three specific variants of these genes (rs6994992 and rs3924999 for Neuregulin 1 and rs10748842 for Neuregulin 3) that have been related to this illness may modify information processing capacity in the cortex, which would be reflected in electrophysiological parameters (P3b amplitude or gamma noise power) and/or cognitive performance. Methods We obtained DNA from 31 patients with schizophrenia and 23 healthy controls and analyzed NRG1 rs6994992, NRG1 rs3924999 and NRG3 rs10748842 promoter polymorphisms by allelic discrimination with real-time polymerase chain reaction (PCR). We compared cognitive outcome, P300 amplitude parameters and an electroencephalographic measure of noise power in the gamma band between the groups dichotomized according to genotype. Results Contrary to our hypothesis, we could not detect any significant influence of variation in Neuregulin 1/Neuregulin 3 polymorphisms on cognitive performance or electrophysiological parameters of patients with schizophrenia. Conclusions Despite our findings, we cannot discard that other genetic variants and, more likely, interactions between those variants and with genetic variation related to different pathways may still influence cerebral processing in schizophrenia

    Surface solitons in two-dimensional chirped photonic lattices

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    We study surface modes in semi-infinite chirped two-dimensional photonic lattices in the frame- work of an effective discrete nonlinear model. We demonstrate that the lattice chirp can change dramatically the conditions for the mode localization near the surface, and we find numerically the families of surface modes, in linear lattices, and discrete surface solitons, in nonlinear lattices. We demonstrate that, in a sharp contrast to one-dimensional discrete surface solitons, in two-dimensional lattices the mode threshold power is lowered by the action of both the surface and lattice chirp. By manipulating with the lattice chirp, we can control the mode position and its localization.Comment: 12 pages, 7 figure

    Observation of surface solitons in chirped waveguide arrays

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    We report the observation of surface solitons in chirped semi-infinite waveguide arrays whose waveguides exhibit exponentially decreasing refractive indices. We show that the power threshold for surface wave formation decreases with an increase of the array chirp and that for sufficiently large chirp values linear surface modes are supported.Comment: 12 pages, 3 figures, to appear in Optics Letter

    Frequency and damping evolution during experimental seismic response of civil engineering structures

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    The results of the seismic tests on several reinforced-concrete shear walls and a four-storey frame are analysed in this paper. Each specimen was submitted to the action of a horizontal accelerogram, with successive growing amplitudes, using the pseudodynamic method. An analysis of the results allows knowing the evolution of the eigen frequency and damping ratio during the earthquakes thanks to an identification method working in the time domain. The method is formulated as a spatial model in which the stiffness and damping matrices are directly identified from the experimental displacements, velocities and restoring forces. The obtained matrices are then combined with the theoretical mass in order to obtain the eigen frequencies, damping ratios and modes. Those parameters have a great relevance for the design of this type of structures

    Late time tails of the massive vector field in a black hole background

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    We investigate the late-time behavior of the massive vector field in the background of the Schwarzschild and Schwarzschild-de Sitter black holes. For Schwarzschild black hole, at intermediately late times the massive vector field is represented by three functions with different decay law Ψ0t(+3/2)sinmt\Psi_{0} \sim t^{-(\ell + 3/2)} \sin{m t}, Ψ1t(+5/2)sinmt\Psi_{1} \sim t^{-(\ell + 5/2)} \sin{m t}, Ψ2t(+1/2)sinmt\Psi_{2} \sim t^{-(\ell + 1/2)} \sin{m t}, while at asymptotically late times the decay law Ψt5/6sin(mt)\Psi \sim t^{-5/6} \sin{(m t)} is universal, and does not depend on the multipole number \ell. Together with previous study of massive scalar and Dirac fields where the same asymptotically late-time decay law was found, it means, that the asymptotically late-time decay law t5/6sin(mt)\sim t^{-5/6} \sin{(m t)} \emph{does not depend} also \emph{on the spin} of the field under consideration. For Schwarzschild-de Sitter black holes it is observed two different regimes in the late-time decay of perturbations: non-oscillatory exponential damping for small values of mm and oscillatory quasinormal mode decay for high enough mm. Numerical and analytical results are found for these quasinormal frequencies.Comment: one author and new material are adde
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