20,564 research outputs found

    Human Resources: Key to Competitive Advantage

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    [Excerpt] As difficult as it may be and as fuzzy as it may turn out, we all must invest in an attempt to peer into the future to discern what implications it has for our human resources. It is not a precise effort, and it certainly can be challenged from many quarters; however, it is not only noble, but may prove to be extremely worthwhile for a competitive firm. As with almost every organization activity, the competitive world makes a paradigm shift inevitable for the human resource function. Understanding the nature of that shift and how to implement meaningful change are the fundamental questions for us all

    On transcendental numbers: new results and a little history

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    Attempting to create a general framework for studying new results on transcendental numbers, this paper begins with a survey on transcendental numbers and transcendence, it then presents several properties of the transcendental numbers ee and π\pi, and then it gives the proofs of new inequalities and identities for transcendental numbers. Also, in relationship with these topics, we study some implications for the theory of the Yang-Baxter equations, and we propose some open problems.Comment: 8 page

    Esthetic rehabilitation with ultra-thin ceramic veneers and direct mock-up in the treatment of dental erosion – Case report

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    Indexación: Scopus.Dental erosion is a high prevalence condition characterized by the loss of dental substance due to chemical agents. It can also be associated with �physical wear, affecting function and aesthetics. Ceramic veneers can provide effective solutions to patients affected by erosive disorders, by means of an indirect approach and minimal intervention. Recent advances in cementation techniques and ceramic materials have allowed their use in reduced thicknesses, known as "dental contact lenses" or "ultra-thin veneers". They contribute significantly to the preservation of the dental structures, having excellent models or mock ups in order to preview the final outcome. Case: The aim of this report is to communicate the use of this technique for the treatment and successful 12-months follow-up of a patient affected by dental erosion of the maxillary central incisors. Special interest was placed on direct mock-up, which is a simple technique not requiring laboratory steps. Luting of the lithium disilicate veneers was carried out with a light-curing resin cement and try-in pastes, yielding a very satisfactory result. Conclusion: Diagnosis and early treatment of this disorder allows the application of conservative techniques, such as ultra-thin veneers, which are seen as a promising alternative treatment to full coverage restorations and traditional ceramic veneers. © 2018, Universidad de Concepcion. All rights reserved.http://joralres.com/index.php/JOR/article/view/481/45

    Influence of statistically distributed point defects on LEED intensities

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    Unparticle contribution to the hydrogen atom ground state energy

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    In the present work we study the effect of unparticle modified static potentials on the energy levels of the hydrogen atom. By using Rayleigh-Schr\"odinger perturbation theory, we obtain the energy shift of the ground state and we compare it with experimental data. Bounds on the unparticle energy scale ΛU\Lambda_\mathcal{U} as a function of the scaling dimension dUd_\mathcal{U} and the coupling constant λ\lambda are derived. We show that there exists a parameter region where bounds on ΛU\Lambda_\mathcal{U} are stringent, signalling that unparticles could be tested in atomic physics experiments.Comment: 11 pages, 3 figure

    Star Integrals, Convolutions and Simplices

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    We explore single and multi-loop conformal integrals, such as the ones appearing in dual conformal theories in flat space. Using Mellin amplitudes, a large class of higher loop integrals can be written as simple integro-differential operators on star integrals: one-loop nn-gon integrals in nn dimensions. These are known to be given by volumes of hyperbolic simplices. We explicitly compute the five-dimensional pentagon integral in full generality using Schl\"afli's formula. Then, as a first step to understanding higher loops, we use spline technology to construct explicitly the 6d6d hexagon and 8d8d octagon integrals in two-dimensional kinematics. The fully massive hexagon and octagon integrals are then related to the double box and triple box integrals respectively. We comment on the classes of functions needed to express these integrals in general kinematics, involving elliptic functions and beyond.Comment: 23 page

    Predicting the connectivity of primate cortical networks from topological and spatial node properties

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    The organization of the connectivity between mammalian cortical areas has become a major subject of study, because of its important role in scaffolding the macroscopic aspects of animal behavior and intelligence. In this study we present a computational reconstruction approach to the problem of network organization, by considering the topological and spatial features of each area in the primate cerebral cortex as subsidy for the reconstruction of the global cortical network connectivity. Starting with all areas being disconnected, pairs of areas with similar sets of features are linked together, in an attempt to recover the original network structure. Inferring primate cortical connectivity from the properties of the nodes, remarkably good reconstructions of the global network organization could be obtained, with the topological features allowing slightly superior accuracy to the spatial ones. Analogous reconstruction attempts for the C. elegans neuronal network resulted in substantially poorer recovery, indicating that cortical area interconnections are relatively stronger related to the considered topological and spatial properties than neuronal projections in the nematode. The close relationship between area-based features and global connectivity may hint on developmental rules and constraints for cortical networks. Particularly, differences between the predictions from topological and spatial properties, together with the poorer recovery resulting from spatial properties, indicate that the organization of cortical networks is not entirely determined by spatial constraints
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