4,529 research outputs found

    Contemporary trends in Brazilian human resource management studies over the last decade (2001–2010)

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    In seeking to detail what is new in the lesser-known field of Brazilian Human Resource Management (HRM) research, this study analyzes 136 recent Brazilian HRM articles over the last decade from 2001 until 2010. Findings reveal that contemporary Brazilian HRM research contains: a wide range of HRM topics; the isomorphic use of some Western HRM themes; and case-based, descriptive methodologies using non-probability sampling. While the number of recently published Brazilian HRM studies has increased, such research seems ripe for further empirical and theoretical development. Our contributions to knowledge lie in: surfacing and classifying recent Brazilian HRM research trends and identifying potentially fruitful areas for future research. Implications for practitioners include the need to attract and retain expert staff, to use more localized pay and reward systems, and to assess the usefulness of HR interventions in the public sector

    Study of the vertical transport in p-doped superlattices based on group III-V semiconductors

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    The electrical conductivity σ has been calculated for p-doped GaAs/Al0.3Ga0.7As and cubic GaN/Al0.3Ga0.7N thin superlattices (SLs). The calculations are done within a self-consistent approach to the k→⋅p→ theory by means of a full six-band Luttinger-Kohn Hamiltonian, together with the Poisson equation in a plane wave representation, including exchange correlation effects within the local density approximation. It was also assumed that transport in the SL occurs through extended minibands states for each carrier, and the conductivity is calculated at zero temperature and in low-field ohmic limits by the quasi-chemical Boltzmann kinetic equation. It was shown that the particular minibands structure of the p-doped SLs leads to a plateau-like behavior in the conductivity as a function of the donor concentration and/or the Fermi level energy. In addition, it is shown that the Coulomb and exchange-correlation effects play an important role in these systems, since they determine the bending potential

    MapRepeat: an approach for effective assembly of repetitive regions in prokaryotic genomes

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    The newest technologies for DNA sequencing have led to the determination of the primary structure of the genomes of organisms, mainly prokaryotes, with high efficiency and at lower costs. However, the presence of regions with repetitive sequences, in addition to the short reads produced by the Next-Generation Sequencing (NGS) platforms, created a lot of difficulty in reconstructing the original genome in silico. Thus, even today, genome assembly continues to be one of the major challenges in bioinformatics specifically when repetitive sequences are considered. In this paper, we present an approach to assemble repetitive regions in prokaryotic genomes. Our methodology enables (i) the identification of these regions through visual tools, (ii) the characterization of sequences on the extremities of gaps and (iii) the extraction of consensus sequences based on mapping of raw data to a reference genome. We also present a case study on the assembly of regions that encode ribosomal RNAs (rRNA) in the genome of Corynebacterium ulceransFRC11, in order to show the efficiency of the strategies presented here. The proposed methods and tools will help in finishing genome assemblies, besides reducing the running time and associated costs. Availability All scripts are available at http://github.com/dcbmariano/maprepea

    Design Thinking: Project Portfolio Management and Simulation – A Creative Mix for Research

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    This paper takes de Bono’s explanation of ‘design thinking’ as the starting point for a report on a doctoral research project that began with a conventional ‘why?’ question, and then, instead of looking for an ‘explanation’, chose to look forward in time to establish an understanding of ‘how to’ think differently about a recurring problem. The catalyst for this work was observation of otherwise competent managers making desperately wrong decisions when good decision making was crucial to their company’s future. The initial choice to ‘look forward’ when designing the research strategy was made well before there was a clear understanding of what was being observed. Given that trajectory, this paper explores the process by which a simulation was created and then used in conjunction with a comparatively new approach to data collection (Explanation looks backwards and design looks forward [1].)

    Ages for exoplanet host stars

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    Age is an important characteristic of a planetary system, but also one that is difficult to determine. Assuming that the host star and the planets are formed at the same time, the challenge is to determine the stellar age. Asteroseismology provides precise age determination, but in many cases the required detailed pulsation observations are not available. Here we concentrate on other techniques, which may have broader applicability but also serious limitations. Further development of this area requires improvements in our understanding of the evolution of stars and their age-dependent characteristics, combined with observations that allow reliable calibration of the various techniques.Comment: To appear in "Handbook of Exoplanets", eds. Deeg, H.J. & Belmonte, J.A, Springer (2018

    Emergent Gauge Fields in Holographic Superconductors

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    Holographic superconductors have been studied so far in the absence of dynamical electromagnetic fields, namely in the limit in which they coincide with holographic superfluids. It is possible, however, to introduce dynamical gauge fields if a Neumann-type boundary condition is imposed on the AdS-boundary. In 3+1 dimensions, the dual theory is a 2+1 dimensional CFT whose spectrum contains a massless gauge field, signaling the emergence of a gauge symmetry. We study the impact of a dynamical gauge field in vortex configurations where it is known to significantly affect the energetics and phase transitions. We calculate the critical magnetic fields H_c1 and H_c2, obtaining that holographic superconductors are of Type II (H_c1 < H_c2). We extend the study to 4+1 dimensions where the gauge field does not appear as an emergent phenomena, but can be introduced, by a proper renormalization, as an external dynamical field. We also compare our predictions with those arising from a Ginzburg-Landau theory and identify the generic properties of Abrikosov vortices in holographic models.Comment: 19 pages, 14 figures, few comments added, version published in JHE

    Innovative Metallic Microfluidic Device for Intensified Biodiesel Production

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    We present a strategy for intensified biodiesel production in a novel metallic microdevice. Additive manufacturing using Selective Laser Melting (SLM) was employed to build the metallic device consisting of multiple micro reactors monolithically integrated with multiple micro heat exchangers. This device allows high conversion rate of biodiesel production with concomitant use of the rejected heat from external source to enhance the reaction temperature and, thereby, its output. The biodiesel production was carried out using soybean oil, ethanol and NaOH as the catalyst. The influences of the reaction temperature and the residence time in the biodiesel production was examined. Biodiesel yield increased with the reaction temperature and a rate of conversion of 99.6% was achieved with a reactor residence time of less than 35 seconds. The work opens up a pathway to exploit waste heat to intensify biodiesel production and contribute significantly to global sustainability

    Anti-inflammatory effects and possible mechanism of action of lupeol acetate isolated from Himatanthus drasticus (Mart.) Plumel

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    <p>Abstract</p> <p>Background</p> <p>The species <it>Himatanthus drasticus </it>is popularly known in Northeast Brazil as "janaguba" and belongs to the family Apocynaceae. The latex collected from its stem bark is used for several purposes including anti-inflammatory properties and presents among its bioactive constituents the pentacyclic triterpene lupeol. The objective of the present work was to study <it>in vivo </it>and <it>in vitro </it>the lupeol acetate (LA) isolated from the plant latex, in several models of inflammation.</p> <p>Methods</p> <p>Male Swiss mice (25-30 g, 6-24 animals per group) were administered with LA, 30 min before the test initiation. In the evaluation of analgesic activity the formalin test was used. The anti-inflammatory activity was evaluated by the following tests: paw edema induced by carrageenan and dextran, and the carrageenan-induced neutrophil migration into peritoneal cavities. Furthermore, the effect of LA on the myeloperoxidase release (MPO, an inflammation biomarker) from human neutrophils was also determined, as well as its antioxidant potential by the DPPH assay.</p> <p>Results</p> <p>In the formalin test, LA (10, 25 and 50 mg/kg, i.p.) inhibited both the 1<sup>st </sup>(neurogenic, 0-5 min) and mainly the 2<sup>nd </sup>(inflammatory, 20-25 min) phase. Naloxone completely reversed the LA effect, indicating the participation of the opioid system. LA also significantly inhibited carrageenan- and dextran-induced paw edemas, as well as the neutrophil migration to the peritoneal cavity evaluated by the carrageenan-induced pleurisia. In this model, the effect of a very low dose of LA (0.1 mg/kg) was potentiated by the same dose of pentoxifylline (PTX), a known TNF-alpha inhibitor. LA (25 and 50 μg/ml) was also very effective in inhibiting MPO released from stimulated human neutrophils, and significantly decreased the number of cells expressing iNOS activity in the paw of mice submitted to carrageenan-induced edema, suggesting a drug involvement with the NO system.</p> <p>Conclusions</p> <p>The anti-inflammatory effect of LA probably involves the opioid system, as indicated by the complete blockade of the opioid antagonist naloxone. Furthermore, the LA effect was potentiated by PTX (a TNF-alpha inhibitor). LA also decreased the number of iNOS cells, suggesting the participation of pro-inflammatory cytokines and the NO system in the drug action.</p
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