2,760 research outputs found

    Are the low-momentum gluon correlations semiclassically determined?

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    We argue that low-energy gluodynamics can be explained in terms of semi-classical Yang-Mills solutions by demonstrating that lattice gluon correlation functions fit to instanton liquid predictions for low energies and, after cooling, in the whole range.Comment: 4 pages, revtex

    Modified instanton profile effects from lattice Green functions

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    We trace here instantons through the analysis of pure Yang-Mills gluon Green functions in the Landau gauge for a window of IR momenta (0.4 GeV <k<0.9< k < 0.9 GeV). We present lattice results that can be fitted only after substituting the BPST profile in the Instanton liquid model (ILM) by one based on the Diakonov and Petrov variational methods. This also leads us to gain information on the parameters of ILM.Comment: 32 pagex, 6 figure

    Anatomical, histochemical and immunohistochemical characterization of the outflow tract of ray hearts (Rajiformes; Chondrichthyes)

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    El resumen aparece en el Program & Abstracts of the 11th International Congress of Vertebrate Morphology, Washington DC 2016. Anatomical Record, Volume 299, Special Feature: 264.Recent work has shown that the cardiac outflow tract of sharks and chimaeras does not consist of a single myocardial component, the conus arteriosus, as classically accepted, but two, namely, the myocardial conus arteriosus and the non-myocardial bulbus arteriosus. However, the anatomical composition of the outflow tract of the batoid hearts remains unknown. The present study was designed to fill this gap. The material examined consisted of hearts of two species of rays, namely, the Mediterranean starry ray (Raja asterias) and sandy ray (Leucoraja circularis). They were studied using scanning electron microscopy, and histochemical and inmunohistochemical techniques. In both species, the outflow tract consists of two components, proximal and distal with regard to the ventricle. The proximal component is the conus arteriosus; it is characterized by the presence of compact myocardium in its wall and several transverse rows of pocket-shaped valves at its luminal side. Each valve consists of a leaflet and its supporting sinus. Histologically, the leaflet has two fibrosas, inner and outer, and a middle coat, the spongiosa. The distal component lacks myocardium. Its wall consists of smooth muscle cells, elastic fibers and collagen. Thus, it shows an arterial-like structure. However, it differs from the aorta because it is covered by the epicardium and crossed by coronary arteries. These findings indicate that the distal component is morphologically equivalent to the bulbus arteriosus of sharks and chimaeras. In contrast to foregoing descriptions, the valves of the first transverse row are distally anchored to the bulbus arteriosus and not to the ventral aorta. Our findings give added support to the notion that presence of a bulbus arteriosus at the arterial pole of the heart is common to all chondrichtyans, and not an apomorphy of actinopterygians as classically thought.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. CGL2014-52356-P, CEIMAR, BIO 203, FEDE

    Fuzzy systems and neural networks XML schemas for soft computing

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    This article presents an XML[2] based language for the specification of objects in the Soft Computing area. The design promotes reuse and takes a compositional approach in which more complex constructs are built from simpler ones; it is also independent of implementation details as the definition of the language only states the expected behaviour of every possible implementation. Here the basic structures for the specification of concepts in the Fuzzy Logic area are described and a simple construct for a generic neural network model is introduced

    BIDAIDEA

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    Monitorizar, analizar, alertar y concientizar a las empresas clientes de BIDAIDEA y a las que se busca hacer clientes, las vulnerabilidades que existen en sus sistemas, desde aplicaciones web hasta servidores con puertos y servicios en uso. Para ello es necesario realizar una serie de pasos para poder llevar a cabo cada una de las auditorias, tanto técnico como administrativo y así poder plasmar el paso a paso de cada uno de los caminos que se encontraron para llegar a explotar las vulnerabilidades que tienen cada uno de los sistemas.ITESO, A.C

    A Ghost Story II: Ghosts, Gluons and the Gluon condensate beyond the IR of QCD

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    Beyond the deep IR, the analysis of ghost and gluon propagators still keeps very interesting non-perturbative information. The Taylor-scheme coupling can be computed and applied to obtain the ΛQCD\Lambda_{\rm QCD} parameter from Landau gauge lattice simulations. Furthermore, a dimension-two gluon condensate, that can be understood in the instanton liquid model, plays an important role in the game.Comment: 12 pp., 3 fig

    Effect of Stakeholders-Oriented Behavior on the Performance of Sustainable Business

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    This study focuses on stakeholder-oriented behavior, throughout organizational culture and organizational behavior, and its effects on the performance of sustainable organizations managed according to Corporative Social Responsibility (CSR) criteria. The investigation demonstrates that the sustainability efforts of a wide range of stakeholders exert various effects on business performance. This investigation tests two integrated conceptual models: (a) Stakeholder Orientation Model estimates the relationships among organizational culture components and their effects on stakeholder-oriented organizational behavior. That is, it estimates the influence of values on norms and artifacts, and their effects on stakeholder-oriented organizational behavior; (b) Performance model estimates the association between stakeholder-oriented organizational behavior and financial and market performance, reputation, and commitment. Using Structural Equation Modelling, both models were estimated from primary data collected from large- and medium-sized multi-sector Colombian companies involved in business sustainability practices. The findings reveal that values are antecedents of norms, but neither values nor norms are predictors of artifacts. Furthermore, norms and artifacts exert direct effects on stakeholder-oriented organizational behavior. In turn, stakeholder-oriented organizational behaviors are predictors of both market performance and commitment. Nevertheless, stakeholder-oriented organizational behaviors are not direct antecedents of both financial performance and reputation.S

    Artificial diet sandwich reveals subsocial behavior in the coffee berry borer Hypothenemus hampei (Coleoptera: Curculionidae: Scolytinae)

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    An artificial diet sandwich, consisting of coffee berry borer artificial diet within two glass plates, has been developed to elucidate the behaviour of the coffee berry borer, an insect that in nature spends most of its life cycle inside the coffee berry. Various types of behaviour have been observed for the first time, including gallery construction, oviposition, gallery blocking, mating and most remarkably, subsocial tasks such as maternal sanitation and tending of eggs and larvae. This observational technique is a breakthrough for studies and manipulations of the coffee berry borer's social behaviour and could be applicable to other bark beetles, consequently yielding important insights into the origin of parental care in scolytine beetles

    Autohydrolysis followed by ionic liquid treatment for Eucalyptus globulus wood fractionation

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    The 2030 Agenda for Sustainable Development recognises the need for a green and sustainable chemistry and engineering [1]. In this context, cleaner processes require the substitution of organic solvents by less harmful solvents. In addition, the solvent selection for a biomass processing is crucial for the environmental sustainability and feasibility of a biorefinery [2]. In this work, water and the ionic liquid 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]) were chosen as green solvents for a selective fractionation of Eucalyptus globulus wood in order to valorise their main fractions (hemicellulose, cellulose and lignin). Two sequential stages were proposed for the biomass processing. First, an autohydrolysis step allowed the hemicellulose solubilisation and its recovery as oligosaccharides in the aqueous liquid phase, yielding a solid phase composed by 60 % glucan and 34 % lignin. Second, a treatment with [C2mim][OAc] was evaluated for the delignification of the autohydrolysed biomass. Optimisation of operational conditions (temperature and time) of the ionic liquid treatment was performed to improve the enzymatic saccharification of cellulose remaining in the solid phase and to solubilise lignin. The proposed process configuration is expected to contribute towards the development of integrated biorefineries based on hardwood biomass.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2019 unit, BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional doNorte, the EcoTech project (POCI01-0145-FEDER-032206). Aloia Romaní thanks the Iacobus Program (European Territorial Cooperation Partnership Galicia – Norte de Portugal) for a mobility fellowship.info:eu-repo/semantics/publishedVersio

    Ghost-gluon coupling, power corrections and ΛMS‾\Lambda_{\overline {\rm MS}} from twisted-mass lattice QCD at Nf=2

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    We present results concerning the non-perturbative evaluation of the ghost-gluon running QCD coupling constant from Nf=2N_f=2 twisted-mass lattice calculations. A novel method for calibrating the lattice spacing, independent of the string tension and hadron spectrum is presented with results in agreement with previous estimates. The value of ΛMS‾\Lambda_{\overline{MS}} is computed from the running of the QCD coupling only after extrapolating to zero dynamical quark mass and after removing a non-perturbative OPE contribution that is assumed to be dominated by the dimension-two \VEV{A^2} gluon condensate. The effect due to the dynamical quark mass in the determination of \Lams is discussed.Comment: 33 pages, 6 fig
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