367 research outputs found

    A parallel algorithm for the partial single-input pole assignment problem

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    AbstractFor a linear control system, we introduce a parallel algorithm to assign a desired subset of eigenvalues to a single-input linear invariant dynamic system. We obtain a sequential algorithm as a particular case. The proposed algorithms are conceptually simple and are based on the computation of left eigenvectors of the state matrix. In addition, the parallel algorithm parallelizes easily as the numerical examples show

    A borane laser

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    © 2015 Macmillan Publishers Limited. Emission from electronically excited species forms the basis for an important class of light sources-lasers. So far, commercially available solution-processed blue-emitting laser materials are based on organic compounds or semiconductor nanocrystals that have significant limitations: either low solubility, low chemical-and/or photo-stability and/or uncompetitive prices. Here we report a novel and competitive alternative to these existing laser materials that is based on boron hydrides, inorganic cluster compounds with a rich and diverse chemistry. We demonstrate that solutions of the borane anti-B 18 H 22 show, under pulsed excitation, blue laser emission at 406 nm with an efficiency (ratio of output/input energies) of 9.5%, and a photostability superior to many of the commercially available state-of-the-art blue laser dyes. This demonstration opens the doors for the development of a whole new class of laser materials based on a previously untapped resource for laser technology-the boranes.Peer Reviewe

    MR imaging features of high-grade gliomas in murine models: How they compare with human disease, reflect tumor biology, and play a role in preclinical trials

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    Murine models are the most commonly used and best investigated among the animal models of HGG. They constitute an important weapon in the development and testing of new anticancer drugs and have long been used in preclinical trials. Neuroimaging methods, particularly MR imaging, offer important advantages for the evaluation of treatment response: shorter and more reliable treatment end points and insight on tumor biology and physiology through the use of functional imaging DWI, PWI, BOLD, and MR spectroscopy. This functional information has been progressively consolidated as a surrogate marker of tumor biology and genetics and may play a pivotal role in the assessment of specifically targeted drugs, both in clinical and preclinical trials. The purpose of this Research Perspectives was to compile, summarize, and critically assess the available information on the neuroimaging features of different murine models of HGGs, and explain how these correlate with human disease and reflect tumor biology.This work was supported by the Programme for Advanced Medical Education from Fundaçâo Champalimaud, Fundaçâo Calouste Gulbenkian, Ministério da Saúde and Fundaçâo para a Ciência e Tecnologia, Portugal, to the first author (A.R.B.), and by grants from the Spanish Ministry of Science and Innovation SAF 2008–01327 and the Community of Madrid S-BIO-2006–0170, to the last author (S.G.C.).Peer Reviewe

    MR imaging features of high-grade gliomas in murine models: How they compare with human disease, reflect tumor biology, and play a role in preclinical trials

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    Murine models are the most commonly used and best investigated among the animal models of HGG. They constitute an important weapon in the development and testing of new anticancer drugs and have long been used in preclinical trials. Neuroimaging methods, particularly MR imaging, offer important advantages for the evaluation of treatment response: shorter and more reliable treatment end points and insight on tumor biology and physiology through the use of functional imaging DWI, PWI, BOLD, and MR spectroscopy. This functional information has been progressively consolidated as a surrogate marker of tumor biology and genetics and may play a pivotal role in the assessment of specifically targeted drugs, both in clinical and preclinical trials. The purpose of this Research Perspectives was to compile, summarize, and critically assess the available information on the neuroimaging features of different murine models of HGGs, and explain how these correlate with human disease and reflect tumor biology.This work was supported by the Programme for Advanced Medical Education from Fundaçâo Champalimaud, Fundaçâo Calouste Gulbenkian, Ministério da Saúde and Fundaçâo para a Ciência e Tecnologia, Portugal, to the first author (A.R.B.), and by grants from the Spanish Ministry of Science and Innovation SAF 2008–01327 and the Community of Madrid S-BIO-2006–0170, to the last author (S.G.C.).Peer Reviewe

    Formalized HR practices and firm performance: An empirical comparison of family and non-family firms

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    ©2019. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/ This document is the Accepted version of a Published Work that appeared in final form in The International Journal of Human Resource Management. To access the final edited and published work see https://doi.org/10.1080/09585192.2017.1289547The influence of the family on human resource (HR) management structures creates important idiosyncrasies with potential implications in terms of firm performance. Based on the agency and socioemotional wealth (SEW) perspectives, this paper examines the formalization and effectiveness of three basic HR practices – selection, training, and compensation – in different contexts of family and non-family firms. Using a sample of 500 Spanish companies, the results show that a higher degree of HR formalization has a positive influence on firm performance, confirming the negative moderating influence of family involvement on the relationship between the formalization of training practices and the firm performance. In addition, the findings indicate that the mediating role of selection practices in the relationship between training and firm performance is smaller in family than in non-family firm

    Prácticas de recursos humanos en la empresa familiar: profesionalización y efecto sobre el desempeño

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    La influencia de la familia en las estructuras de gestión del capital humano de la empresa crea un marco único y diferente, con importantes implicaciones en términos de eficiencia. En este trabajo se examina la orientación de las principales prácticas de recursos humanos –selección, formación y retribución- y sus efectos sobre el desempeño organizativo en función de la presencia de la familia en la propiedad y dirección del negocio. Utilizando una muestra de 500 empresas españolas, los resultados indican que en las empresas de dirección familiar se aplican unas prácticas de recursos humanos menos formalizadas y profesionalizadas que en las empresas familiares de dirección externa. Asimismo, se comprueba una contribución de las prácticas de recursos humanos a través de la selección que se encuentra moderada negativamente por el carácter familiar.&nbsp

    Amino acids content in 'Tempranillo' must from three soil types over four vintages

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    Amino acids are the main grape nitrogen compounds and the principal source of N for yeasts, being precursors of several volatile compounds. Therefore, N compound concentrations in musts can affect sensorial characteristics of wines. The aim of this study was to analyse the influence of N-NO3- and N-NH4+ contents from different soils on profile and content of amino acids in 'Tempranillo' grapes. In order to determine this soil influence on must quality, three plots were selected in AOC Rioja, classified as Fluventic Haploxerepts, Typic Calcixerepts, and Petrocalcic Palexerolls. The results showed that amino acids and yeast assimilable nitrogen (YAN) content allowed us to differentiate samples from the three soils, and in each soil type, samples of each season. In general, must contents of total amino acids and some of them, as alanine, threonine, and tyrosine, were more influenced by soil type; YAN, proline, histidine, serine, and glycine concentrations mainly depended on the interaction soil-vintage. In conclusion, free amino acids concentration could be a tool to differentiate musts coming from different soils
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