7,952 research outputs found

    Tripartite Graph Clustering for Dynamic Sentiment Analysis on Social Media

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    The growing popularity of social media (e.g, Twitter) allows users to easily share information with each other and influence others by expressing their own sentiments on various subjects. In this work, we propose an unsupervised \emph{tri-clustering} framework, which analyzes both user-level and tweet-level sentiments through co-clustering of a tripartite graph. A compelling feature of the proposed framework is that the quality of sentiment clustering of tweets, users, and features can be mutually improved by joint clustering. We further investigate the evolution of user-level sentiments and latent feature vectors in an online framework and devise an efficient online algorithm to sequentially update the clustering of tweets, users and features with newly arrived data. The online framework not only provides better quality of both dynamic user-level and tweet-level sentiment analysis, but also improves the computational and storage efficiency. We verified the effectiveness and efficiency of the proposed approaches on the November 2012 California ballot Twitter data.Comment: A short version is in Proceeding of the 2014 ACM SIGMOD International Conference on Management of dat

    Phenomenological model for symmetry breaking in chaotic system

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    We assume that the energy spectrum of a chaotic system undergoing symmetry breaking transitions can be represented as a superposition of independent level sequences, one increasing on the expense of the others. The relation between the fractional level densities of the sequences and the symmetry breaking interaction is deduced by comparing the asymptotic expression of the level-number variance with the corresponding expression obtained using the perturbation theory. This relation is supported by a comparison with previous numerical calculations. The predictions of the model for the nearest-neighbor-spacing distribution and the spectral rigidity are in agreement with the results of an acoustic resonance experiment.Comment: accepted for publication in Physical Review

    Molecular Evaluation of exons 8 and 22 of the SHANK3 gene in Autism Spectrum Disorders

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    Autism spectrum disorders are a group of neurodevelopmental disorders with a complex and heterogeneous etiology. Studies have shown that genetic factors play an important role in the aetiology of these diseases. Recently, de novo mutations, frameshifts and deletions have been described in the SHANK3 gene, also known as ProSAP2 gene, which encodes a synaptic scaffolding protein. All the participants of this study had normal karyotypes and underwent screening for Fragile-X syndrome. Subsequently, they were analyzed by direct sequencing of different points of exons 8 and 22 of the SHANK3 gene. None of the study participants presented with changes in these regions. These findings may be due to the fact that mutations, deletions and duplications of the SHANK3 gene are rare

    Analytical results for a Bessel function times Legendre polynomials class integrals

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    When treating problems of vector diffraction in electromagnetic theory, the evaluation of the integral involving Bessel and associated Legendre functions is necessary. Here we present the analytical result for this integral that will make unnecessary numerical quadrature techniques or localized approximations. The solution is presented using the properties of the Bessel and associated Legendre functions.Comment: 4 page

    Comparative Analysis of three Growth Medium for Arthrospira platensis Cultivation based on Lab-Scale Results

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    Arthrospira platensis is a rich source of essential amino acids, vitamins and it is used as a feedstock for energy sources. The high cost of the growth medium used in its cultivation is a problem for increasing the production viability. The present study aimed to compare the technical viability and the cost elementsin different growth medium for A. platensis cultivation. For that purpose, it was proposed the use of three different growth medium, named as M1, M2 and M3 in a lab scale. The growth of the treatments presented a microbial process with characteristic phases. M1, M2 and M3 maximum concentration (Xmax), productivity (Px) and the maximum specific growth rate (μmax) showed no significant difference among treatments. However, M3 presented the lowest cost element, about 45.75% less than the M1 and 38.92% lower than M2. Therefore, the comparison enabled the result that M3 presented the best performance to be used, thus increasing profitability of this production in a lab-scale analysis

    Indexação de plantas básicas de citros da Embrapa Mandioca e Fruticultura para a presença de viróides.

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    Os citros são hospedeiros naturais de espécies de viróides: viróide da exocorte dos citros (Citrus exocortis viroid, CEVd), viróide do nanismo do lúpulo (Hop stunt viroid, HSVd), Citrus bark cracking viroid (CBCVd), viróide da folha curvada dos citros (Citrus bent leaf viroid, CBLVd), viróide do nanismo dos citros (Citrus dwarfing viroid, CDVd) e, mais recentemente, também foi descrita a ocorrência do Citrus Viroid V (CVd-V) e Citrus viroid VI (CVd-VI). Somente o CEVd e variantes do HSVd são agentes causais de doenças, exocorte e xiloporose, respectivamente. No Brasil já foram identificados as espécies CEVd, HSVd e o CDVd
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