3,609 research outputs found

    On Anisotropy of Ultra-High Energy Cosmic-Rays

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    We briefly summarize our study on anisotropy of Ultra-High Energy Cosmic-Rays (UHECRs), in which we define a statistics that measures the correlation between UHECRs and Large Scale Structure (LSS). We also comment here on recently published paper by Koers and Tinyakov that compared our statistics to improved KS statistics.Comment: 3 pages, 2 figures, proceedings of PANIC 2008. v2: version match publication in Nuclear Physics

    QCD corrections to e+eu dˉ s cˉe^+ e^- \to u~\bar d~s~\bar c at Lep 2 and the Next Linear Collider: CC11 at O(\alpha_s)

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    QCD one-loop corrections to the full gauge invariant set of electroweak diagrams describing the hadronic process e+eu dˉ s cˉe^+ e^- \to u~\bar d~s~\bar c are computed. Four-jet shape variables for WWWW events are studied at next-to-leading order and the effects of QCD corrections on the determination of the WW--mass in the hadronic channel at Lep 2 and NLC is discussed. We compare the exact calculation with a ``naive''approach to strong radiative corrections which has been widely used in the literature.Comment: 10 pages, 4 ps figures, requires axodra

    Have Cherenkov telescopes detected a new light boson?

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    Recent observations by H.E.S.S. and MAGIC strongly suggest that the Universe is more transparent to very-high-energy gamma rays than previously thought. We show that this fact can be reconciled with standard blazar emission models provided that photon oscillations into a very light Axion-Like Particle occur in extragalactic magnetic fields. A quantitative estimate of this effect indeed explains the observed data and in particular the spectrum of blazar 3C279.Comment: 3 pages, 1 figure, Proceeding of the "Eleventh International Workshop on Topics in Astroparticle and Underground Physics" (TAUP), Roma, Italy, 1 - 5 July 2009 (to be published in the Proceedings

    Evaluation of cervical posture improvement of children with cerebral palsy after physical therapy based on head movements and serious games

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    Background: This paper presents the preliminary results of a novel rehabilitation therapy for cervical and trunk control of children with cerebral palsy (CP) based on serious videogames and physical exercise. Materials: The therapy is based on the use of the ENLAZA Interface, a head mouse based on inertial technology that will be used to control a set of serious videogames with movements of the head. Methods: Ten users with CP participated in the study. Whereas the control group (n=5) followed traditional therapies, the experimental group (n=5) complemented these therapies with a series of ten sessions of gaming with ENLAZA to exercise cervical flexion-extensions, rotations and inclinations in a controlled, engaging environment. Results: The ten work sessions yielded improvements in head and trunk control that were higher in the experimental group for Visual Analogue Scale, Goal Attainment Scaling and Trunk Control Measurement Scale (TCMS). Significant differences (27% vs. 2% of percentage improvement) were found between the experimental and control groups for TCMS (p<0.05). The kinematic assessment shows that there were some improvements in the active and the passive range of motion. However, no significant differences were found pre- and post-intervention. Conclusions:Physical therapy that combines serious games with traditional rehabilitation could allow children with CP to achieve larger function improvements in the trunk and cervical regions. However, given the limited scope of this trial (n=10) additional studies are needed to corroborate this hypothesis

    A connectivity rating for vertices in networks

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    We compute the influence of a vertex on the connectivity structure of a directed network by using Shapley value theory. In general, the computation of such ratings is highly inefficient. We show how the computation can be managed for many practically interesting instances by a decomposition of large networks into smaller parts. For undirected networks, we introduce an algorithm that computes all vertex ratings in linear time, if the graph is cycle composed or chordal.4th IFIP International Conference on Theoretical Computer ScienceRed de Universidades con Carreras en Informática (RedUNCI

    Hartree-Fock-Bogoliubov theory versus local-density approximation for superfluid trapped fermionic atoms

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    We investigate a gas of superfluid fermionic atoms trapped in two hyperfine states by a spherical harmonic potential. We propose a new regularization method to remove the ultraviolet divergence in the Hartree-Fock-Bogoliubov equations caused by the use of a zero-range atom-atom interaction. Compared with a method used in the literature, our method is simpler and has improved convergence properties. Then we compare Hartree-Fock-Bogoliubov calculations with the semiclassical local-density approximation. We observe that for systems containing a small number of atoms shell effects, which cannot be reproduced by the semiclassical calculation, are very important. For systems with a large number of atoms at zero temperature the two calculations are in quite good agreement, which, however, is deteriorated at non-zero temperature, especially near the critical temperature. In this case the different behavior can be explained within the Ginzburg-Landau theory.Comment: 12 pages, 8 figures, revtex; v2: references and clarifying remarks adde

    A new light boson from MAGIC observations?

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    Recent detection of blazar 3C279 by MAGIC has confirmed previous indications by H.E.S.S. that the Universe is more transparent to very-high-energy gamma rays than currently thought. This circumstance can be reconciled with observations of nearby blazars provided that photon oscillations into a very light Axion-Like Particle occur in extragalactic magnetic fields. The emerging "DARMA scenario" can be tested in the near future by the satellite-borne Fermi LAT detector as well as by the ground-based Imaging Atmospheric Cherenkov Telescopes H.E.S.S., MAGIC, CANGAROO III, VERITAS and by the Extensive Air Shower arrays ARGO-YBJ and MILAGRO.Comment: 4 pages, 1 figure, Proceeding of the "Neutrino Oscillation Workshop", Conca Specchiulla, Otranto, Italy, 6-12 September 200

    Análisis del discurso multimodal de las caricaturas sobre Alejandro Toledo de “Otra vez Andrés” del diario El Comercio, enero - julio 2019

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    En la presente tesis se planteó el siguiente problema de investigación: ¿Cómo se presenta el discurso multimodal de las caricaturas sobre Alejandro Toledo de “Otra vez Andrés” del diario El Comercio, durante el periodo enero - julio 2019? Asimismo, tuvo como objetivo analizar el discurso multimodal de las caricaturas sobre el caso Alejandro Toledo de “Otra vez Andrés” en el diario El Comercio, durante el periodo enero - julio 2019. La investigación realizada fue de enfoque cualitativo de tipo básica, de nivel hermenéutica con un diseño de estudio del caso. Se utilizó la técnica de la observación, y el instrumento denominado ficha de observación, cuyo facto de validación fue de un 91%. Posteriormente se llegó a la conclusión que el discurso multimodal de las caricaturas sobre Alejandro Toledo de “Otra vez Andrés” que aparecen en el diario El Comercio se desarrolló de manera adecuada, ya que la utilización y distribución de sus principales componentes como lo son el discurso, la gráfica y la producción logran que el mensaje transmitido en las caricaturas sea entendible y asimilado rápidamente por los lectores

    Improved harmonic performance of cascaded H-Bridge converters with thermal control

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    Among multilevel converter topologies, the cascaded H-bridge converter (CHB) is one suitable solution for multiple applications such as flexible ac transmission systems and motor drives. CHB presents a natural high modularity because it is formed by the serial connection of H-bridges. This paper deals with a CHB where the cells do not have the same aging because the maintenance during the years of operation forces to replace some damaged cells of the converter with new or repaired ones. A method based on clamping one power cell can be used to reduce the power losses of that cell reducing its temperature and increasing its lifetime. However, clamping one cell of the CHB introduces high harmonic distortion around twice the carrier frequency due to the CHB unbalanced operation when a conventional phase-shifted PWM is applied. A deep harmonic distortion analysis of the CHB output voltage with thermal control based on clamping one cell is presented. Using this analysis, the harmonic distortion at twice the carrier frequency is eliminated applying a non-conventional phase-shifted PWM where the angles between the carriers of consecutive power cells are modified. Experimental results show how the thermal control applying the clamping of a power cell is achieved whilst the harmonic distortion around twice the carrier frequency is eliminated

    Development of NASH in Obese Mice is Confounded by Adipose Tissue Increase in Inflammatory NOV and Oxidative Stress

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    Aim. Nonalcoholic steatohepatitis (NASH) is the consequence of insulin resistance, fatty acid accumulation, oxidative stress, and lipotoxicity.We hypothesize that an increase in the inflammatory adipokine NOV decreases antioxidant Heme Oxygenase 1 (HO- 1) levels in adipose and hepatic tissue, resulting in the development of NASH in obese mice. Methods. Mice were fed a high fat diet (HFD) and obese animals were administered an HO-1 inducer with or without an inhibitor of HO activity to examine levels of adipose-derived NOV and possible links between increased synthesis of inflammatory adipokines and hepatic pathology. Results. NASH mice displayed decreased HO-1 levels and HO activity, increased levels of hepatic heme, NOV, MMP2, hepcidin, and increased NAS scores and hepatic fibrosis. IncreasedHO-1 levels are associated with a decrease in NOV, improved hepatic NAS score, ameliorated fibrosis, and increases in mitochondrial integrity and insulin receptor phosphorylation. Adipose tissue function is disrupted in obesity as evidenced by an increase in proinflammatory molecules such as NOV and a decrease in adiponectin. Importantly, increased HO-1 levels are associated with a decrease of NOV, increased adiponectin levels, and increased levels of thermogenic and mitochondrial signaling associated genes in adipose tissue. Conclusions.These results suggest that the metabolic abnormalities in NASH are driven by decreased levels of hepatic HO-1 that is associated with an increase in the adipose-derived proinflammatory adipokine NOV in our obese mouse model of NASH. Concurrently, induction of HO-1 provides protection against insulin resistance as seen by increased insulin receptor phosphorylation. Pharmacological increases in HO-1 associated with decreases in NOV may offer a potential therapeutic approach in preventing fibrosis, mitochondrial dysfunction, and the development of NASH
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