1,890 research outputs found

    Cross-Validation of Functional MRI and Paranoid-Depressive Scale: Results From Multivariate Analysis.

    Get PDF
    Introduction: There exists over the past decades a constant debate driven by controversies in the validity of psychiatric diagnosis. This debate is grounded in queries about both the validity and evidence strength of clinical measures. Materials and Methods: The objective of the study is to construct a bottom-up unsupervised machine learning approach, where the brain signatures identified by three principal components based on activations yielded from the three kinds of diagnostically relevant stimuli are used in order to produce cross-validation markers which may effectively predict the variance on the level of clinical populations and eventually delineate diagnostic and classification groups. The stimuli represent items from a paranoid-depressive self-evaluation scale, administered simultaneously with functional magnetic resonance imaging (fMRI). Results: We have been able to separate the two investigated clinical entities - schizophrenia and recurrent depression by use of multivariate linear model and principal component analysis. Following the individual and group MLM, we identified the three brain patterns that summarized all the individual variabilities of the individual brain patterns. Discussion: This is a confirmation of the possibility to achieve bottom-up classification of mental disorders, by use of the brain signatures relevant to clinical evaluation tests

    Accurate crab cavity modeling for the high luminosity Large Hadron Collider

    Get PDF
    As part of the Large Hadron Collider high luminosity upgrade it is proposed to include crab cavities in the lattice in order to enhance the luminosity. For one proposed cavity design the dynamics of the cavity is considered in terms of its impact upon the dynamic aperture of the machine. Taylor maps of the cavity are created and used to perform this analysis with a full assessment of their validity. Furthermore from these Taylor maps, symplectic methods are developed further, guided by the knowledge gained in the study of the physics contained in them

    The contribution of sulfate ions and protons to the specific capacitance of microporous carbon monoliths

    Get PDF
    The monoliths studied in this work show large specific surface areas (up to 1600 m2 g-1), high densities (up to 1.17 g cm -3) and high electrical conductivities (up to 9.5 S cm-1). They are microporous carbons with pore sizes up to 1.3 nm but most of them below 0.75 nm. They also show oxygen functionalities. The electrochemical behavior of the monoliths is studied in three-electrode cells with aqueous H2SO4 solution as electrolyte. This work deals with the contribution of the sulfate ions and protons to the specific capacitance of carbon monoliths having different surface areas and different contents of oxygen groups. Protons contribute with a pseudocapacitance (up to 152 F g -1) in addition to the double layer capacitance. Sulfate ions contribute with a double layer capacitance only. At the double layer, the capacitance of the sulfate ions (up to 291 F g-1) is slightly higher than that of protons (up to 251 F g-1); both capacitances increase as the surface area increases. The preference of protons to be electroadsorbed at the double layer and the broader voltage window of these ions account for their higher contribution (70%) to the double layer capacitance. © 2014 Elsevier B.V. All rights reserved.Financial support through the projects MAT2011-25198, MP 1004 and PROMETEO/2009/047 is gratefully acknowledged. V.B. thanks MINECO for R&C contract.Peer Reviewe

    PROPUESTA ARQUITECTÓNICA PARA EL DESARROLLO DE APLICACIONES COLABORATIVAS DE CALIDAD

    Get PDF
    RESUMEN  Este artículo describe una propuesta arquitectónica basada en servicios web orientada al desarrollo de aplicaciones colaborativas de calidad. La arquitectura ha sido diseñada para abordar las carencias que presentan los modelos arquitectónicos y entornos existentes para el desarrollo de este tipo de aplicaciones. Estas limitaciones incluyen dependencias de plataformas, lenguajes y sistemas operativos, así como el hecho de que su funcionalidad, a menudo, está pensada para aplicaciones muy concretas. Nuestra propuesta, gracias a su diseño y a que está basada en servicios web, es capaz de proporcionar aplicaciones con atributos no funcionales (específicamente, atributos de calidad) como reusabilidad, portabilidad, interoperabilidad, ubicuidad y adaptabilidad, permitiendo reorganizar dinámicamente los componentes para adaptar la arquitectura a la forma en que se organiza el trabajo en grupo en cada momento. Dicha adaptación puede lograse, si es necesario, extendiendo la propuesta con nuevos servicios (que pueden ser aplicaciones, componentes o herramientas) cuando éstos se requieran, de manera consistente y sin necesidad de realizar modificaciones en los servicios existentes. Además, el grupo puede adaptarse a nuevas necesidades o estilos de trabajo,gracias a que nuestra arquitectura permite modificar las políticas de manejo de sesión en tiempo de ejecución. Nuestra propuesta también resuelve problemas significativos encontrados en los modelos y entornos existentes para el desarrollo de aplicaciones colaborativas, como el hecho de que no proporcionan sesiones flexibles y/o no suministran un modelo consistente para integrar componentes de terceros. PALABRAS CLAVE Arquitectura SoftwareAtributos de CalidadAplicaciones ColaborativasServiciosWebArquitectura Orientada a Servicios ABSTRACT This article describes a web service-based architectural proposal oriented to the development of quality collaborative applications. The architecture has been designed to overcome the lacks that existing architectural models and environments for developing this type of applications present. These limitations include platform, language and operative system dependencies, and also the fact that their functionality is often intended for very specific applications. Our proposal, thanks to its design and since it is based on web services, is able to provide applications with non functional attributes (specifically, quality attributes) such as reusability, portability, interoperability, ubiquity and adaptability, which allow to dynamically reorganize the components in order to adapt the architecture to the form in which groupwork is organized at each moment. This adaptation can be achieved, if necessary, extending the proposal with new services (which can be applications, components or tools) when these are required, in a consistent way and without necessity to modify existing services. Moreover, the group can adapt to different needsand work styles, thanks to our architecture allows to modify the session management policies in run time. Our proposal also solves significant problems found in the existing models and environments for the development of collaborative applications, as the fact that they do not provide flexible sessions and/or they do not provide a consistent model to integrate third-party components. KEYWORDSSoftware ArchitectureQuality AttributesCollaborative ApplicationsWeb ServicesService-Oriented Architecture (SOA)

    Bose-Fermi Mixtures in Optical Lattices

    Get PDF
    Using mean field theory, we have studied Bose-Fermi mixtures in a one-dimensional optical lattice in the case of an attractive boson-fermion interaction. We consider that the fermions are in the degenerate regime and that the laser intensities are such that quantum coherence across the condensate is ensured. We discuss the effect of the optical lattice on the critical rotational frequency for vortex line creation in the Bose-Einstein condensate, as well as how it affects the stability of the boson-fermion mixture. A reduction of the critical frequency for nucleating a vortex is observed as the strength of the applied laser is increased. The onset of instability of the mixture occurs for a sizeably lower number of fermions in the presence of a deep optical lattice.Comment: 7 pages, 6 figures, revtex4, 14th International Laser Physics Workshop (LPHYS'05

    Paper-based ZnO self-powered sensors and nanogenerators by plasma technology

    Full text link
    Nanogenerators and self-powered nanosensors have shown the potential to power low-consumption electronics and human-machine interfaces, but their practical implementation requires reliable, environmentally friendly and scalable, processes for manufacturing and processing. This article presents a plasma synthesis approach for the fabrication of piezoelectric nanogenerators (PENGs) and self-powered sensors on paper substrates. Polycrystalline ZnO nanocolumnar thin films are deposited by plasma-enhanced chemical vapour deposition on common paper supports using a microwave electron cyclotron resonance reactor working at room temperature yielding high growth rates and low structural and interfacial stresses. Applying Kinetic Monte Carlo simulation, we elucidate the basic shadowing mechanism behind the characteristic microstructure and porosity of the ZnO thin films, relating them to an enhanced piezoelectric response to periodic and random inputs. The piezoelectric devices are assembled by embedding the ZnO films in PMMA and using Au electrodes in two different configurations: laterally and vertically contacted devices. We present the response of the laterally connected devices as a force sensor for low-frequency events with different answers to the applied force depending on the impedance circuit, i.e. load values range, a behaviour that is theoretically analyzed. The vertical devices reach power densities as high as 80 nW/cm2 with a mean power output of 20 nW/cm2. We analyze their actual-scenario performance by activation with a fan and handwriting. Overall, this work demonstrates the advantages of implementing plasma deposition for piezoelectric films to develop robust, flexible, stretchable, and enhanced-performance nanogenerators and self-powered piezoelectric sensors compatible with inexpensive and recyclable supportsComment: 30 pages, 8 figures in main tex

    Confronting Spin Flavor Solutions of the Solar Neutrino Problem with current and future solar neutrino data

    Get PDF
    We show that spin flavor precession solutions to the solar neutrino problem, although preferred by the latest solar data, are ruled out by the first results from the KamLAND reactor experiment, at more than 3_sigma. An illustrative chi2 plot comparing these descriptions with oscillations is given.Comment: new appendix added discussing the impact of the KamLAND data. This updates the one published in Phys.Rev.D66:093009,200

    Constraining neutrino oscillation parameters with current solar and atmospheric data

    Get PDF
    We analyze the impact of recent solar, atmospheric and reactor data in the determination of the neutrino oscillation parameters, taking into account that both the solar nu_e and the atmospheric nu_mu may convert to a mixture of active and sterile neutrinos. We use the most recent global solar neutrino data, including the 1496-day Super-K neutrino data sample, and we investigate in detail the impact of the SNO neutral current, spectral and day/night data by performing also an analysis using only the charged current rate from SNO. The implications of the first 145.1 days of KamLAND data on the determination of the solar neutrino parameters are also discussed in detail. We confirm the clear preference of solar+reactor data for the pure active LMA-MSW solution of the solar neutrino problem, and obtain that the LOW, VAC, SMA and Just-So^2 solutions are disfavored with a Delta_chi^2 = 22, 22, 36, 44, respectively. Furthermore, we find that the global solar data constrains the admixture of a sterile neutrino to be less than 43% at 99% CL. By performing an improved fit of the atmospheric data, we also update the corresponding regions of oscillation parameters. We find that the recent atmospheric Super-K (1489-day) and MACRO data have a strong impact on constraining a sterile component in atmospheric oscillations: if the nu_mu is restricted to the atmospheric mass states only a sterile admixture of 16% is allowed at 99% CL, while a bound of 35% is obtained in the unconstrained case. Pure sterile oscillations are disfavored with a Delta_chi^2 = 34.6 compared to the pure active case.Comment: 28 pages, LaTeX file using RevTEX4, 12 figures and 3 tables included. Improved version including the new KamLAND dat

    Dense carbon monoliths for supercapacitors with outstanding volumetric capacitances

    Get PDF
    A commercially available dense carbon monolith (CM) and four carbon monoliths obtained from it have been studied as electrochemical capacitor electrodes in a two-electrode cell. CM has: (i) very high density (1.17 g cm−3), (ii) high electrical conductivity (9.3 S cm−1), (iii) well-compacted and interconnected carbon spheres, (iv) homogeneous microporous structure and (v) apparent BET surface area of 957 m2g−1. It presents interesting electrochemical behaviors (e.g., excellent gravimetric capacitance and outstanding volumetric capacitance). The textural characteristics of CM (porosity and surface chemistry) have been modified by means of different treatments. The electrochemical performances of the starting and treated monoliths have been analyzed as a function of their porous textures and surface chemistry, both on gravimetric and volumetric basis. The monoliths present high specific and volumetric capacitances (292 F g−1 and 342 F cm−3), high energy densities (38 Wh kg−1 and 44 Wh L−1), and high power densities (176 W kg−1 and 183 W L−1). The specific and volumetric capacitances, especially the volumetric capacitance, are the highest ever reported for carbon monoliths. The high values are achieved due to a suitable combination of density, electrical conductivity, porosity and oxygen surface content.Financial support from projects MAT2011-25198, MP1004 and PROMETEO/2009/047 is gratefully acknowledged. V.B. thanks MINECO for R&C contract
    corecore