2,208 research outputs found

    Mobile Music Distribution: A Multichannel Approach

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    In contrast to what is happening in the Internet-based scenario, the music market in the mobile scenario is far from beingconsidered a large success. Several studies state that excessive downloading time and high cost are the main burdens.Motivated by the growth of social and mobile applications, in this paper we propose an approach that aims at reducing both the downloadingtime and the cost to get digital music when acquired in the mobile scenario. The proposed architecture exploits the usage ofpersonal communication technologies embedded in cellphones (e.g., Bluetooth and Wi-Fi) to couple the current distributionmodel (mainly based on 3G networks), so as to provide a multichannel distribution model where users are free to redistributedigitalmusic. The architecture includes a license-based securitymechanism that prevents unauthorized usage of digitalmusic, and makes use of an incentive mechanism to stimulate and reward the music distribution among customers. By analyzing pros and cons of the music distribution chain, results show that the proposed architecture might help in reducing both the downloading time and the cost to get digital music when acquired in the mobile scenario. Therefore, it might be helpful to the success of the mobile music scenario

    Method for analyzing web space data

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    A method for analyzing data from the web that determine the importance that a chosen subject has in society, e.g., subject matter relating a concert, a scientific discovery, a football match, a person, a corporation, a brand, or a car, and analyze such data that can represent the entire society better than the known techniques. The method according to the invention can avoid malicious alterations and is able to measure and detect the temporal relations among all the web resources that talk about a particular topic or subject matter

    Location privacy and public metadata in social media platforms: attitudes, behaviors and opinions

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    The highavailability of geolocation technologies is changing the social media mobile scenario and is exposing users to privacy risks. Different studies have focused on location privacy in the mobile scenario, but the results are conflicting: some say that users are concerned about location privacy, others say they are not. In this paper, we initially investigate attitudes and behaviors of people toward a location-aware scenario; then, we show users the amount of personal and sensitive data that can be extracted from contents publicly available in social platforms, and finally we ask for their opinions about a location-aware scenario. Results show that people who were not initially concerned about privacy are the most worried about the location-aware scenario; conversely, people who were initially concerned are less worried about the location-aware scenario and find the scenario interesting. A deeper analysis of the obtained results allows us to draw guidelines that might be helpful to build an effective location-aware scenario

    A computational model of gene expression in an inducible synthetic circuit

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    Synthetic biology aims to the rational design of gene circuits with predictable behaviours. Great efforts have been done so far to introduce in the field mathematical models that could facilitate the design of synthetic networks. Here we present a mathematical model of a synthetic gene-circuit with a negative feedback. The closed loop configuration allows the control of transcription by an inducer molecule (IPTG). Escherichia coli bacterial cells were transformed and expression of a fluorescent reporter (GFP) was measured for different inducer levels. Computer model simulations well reproduced the experimental induction data, using a single fitting parameter. Independent genetic components were used to assemble the synthetic circuit. The mathematical model here presented could be useful to predict how changes in these genetic components affect the behaviour of the synthetic circuit

    Editorial: Environmental phytoremediation: plants and microorganisms at work

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    Human industry, farming, and waste disposal practices have resulted in the large-scale contamination of soil and water with organic compounds and heavy metals, with detrimental effects on ecosystems and human health. Conventional soil remediation methods are expensiveand often involve the storage of soil in designated areas, postponing rather than solving the problem. In the last decade, the pressing need to find alternative methods has highlighted the scientific and economic benefits of plants and their associated microorganisms, which can beused for the reclamation of polluted soil and water (Meagher, 2000). This is an elegant and low-cost approach for the decontamination of polluted sites and has been greeted with a high degree of public acceptance, therefore prompting research into the use of phytoremediation technology to address the large areas of land and water currently affected (reviewed by Kr\ue4mer,2005; Vangronsveld et al., 2009; Lee, 2013). This Frontiers in Plant Science research topic provides a snapshot of current research into the application of environmental phytoremediation strategies

    VSCAN: An Enhanced Video Summarization using Density-based Spatial Clustering

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    In this paper, we present VSCAN, a novel approach for generating static video summaries. This approach is based on a modified DBSCAN clustering algorithm to summarize the video content utilizing both color and texture features of the video frames. The paper also introduces an enhanced evaluation method that depends on color and texture features. Video Summaries generated by VSCAN are compared with summaries generated by other approaches found in the literature and those created by users. Experimental results indicate that the video summaries generated by VSCAN have a higher quality than those generated by other approaches.Comment: arXiv admin note: substantial text overlap with arXiv:1401.3590 by other authors without attributio

    Características agronômicas dos acessos do Banco Ativo de Germoplasma de Uva.

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    Este trabalho teve por objetivo caracterizar agronomicamente 19 acessos do Banco Ativo de Germoplasma de Uva (BAGUva), por um período compreendido entre sete e 11 anos. Os materiais são cultivados a campo, em condições padronizadas, sob porta-enxerto '101-14?, com sistema de sustentação em espaldeira e poda em Guyot. Foram avaliadas características relacionadas ao cacho, à baga, à produtividade e à incidência das principais doenças da videira no país

    Comparison between microsatellites and Ml MntH gene as targets to identify Mycobacterium leprae by PCR in leprosy

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    FUNDAMENTOS: PCR tem sido frequentemente utilizada no diagnóstico molecular da hanseníase. OBJETIVOS: comparar os resultados da PCR com 4 pares de primers específicos para Mycobacterium leprae, bem como os resultados da PCR à classificação operacional, segundo a OMS, de multibacilar (MB) e paucibacilar (PB) da hanseníase. MÉTODO: Vinte e oito amostras de DNA, extraído de biópsias congeladas de pele e de imprint de biópsias em papel de filtro de 23 pacientes (14 MB e 9 PB), foram utilizadas na PCR com primers que amplificam 131pb, 151pb e 168pb de regiões de microssatélites, e um fragmento de 336pb do gene Ml MntH (ML2098) do bacilo. RESULTADOS: O bacilo pôde ser detectado em 22 (78,6%) das 28 amostras. Nove (45%) das 20 amostras de biópsia e 6 (75%) das 8 amostras de imprints foram positivas para TTC. Sete (35,5%) amostras de biópsias e 5 (62,5%) imprints foram positivos para AGT, e 11 (55%) biópsias e 4 (50%) imprints foram positivos para AT. Oito (38%) amostras de biópsias e 5 (62,5%) imprints foram positivos para o gene Ml MntH. Dentre o grupo MB, os microssatélites detectaram o bacilo em 78,5% das amostras, e o gene Ml MntH, em 57,1% das amostras, independentemente do material clínico. No grupo PB, 55,5% das amostras foram positivas para os microssatélites, enquanto que 22,2% o foram para o gene Ml MntH. CONCLUSÕES: Estes resultados mostram que, tanto as regiões específicas de microssatélites quanto o gene Ml MntH, podem representar ferramentas úteis na detecção do Ml MntH por PCR em amostras de biópsias e imprint de biópsiasBACKGROUND: The Polymerase Chain Reaction (PCR) technique has been frequently used in the molecular diagnosis of leprosy. OBJECTIVES: To compare the results of PCR with four pairs of Mycobacterium leprae specific primers as well as to compare these results to multibacillary (MB) and paucibacillary (PB) leprosy according to the WHO operational classification. METHOD: 28 DNA samples, collected from the frozen skin biopsies and biopsy imprints on filter paper of 23 patients (14 MB and PB 9), were examined for PCR using primers which amplify 131, 151 and 168bp of specific microsatellite regions and a 336 fragment of the Ml MntH (ML2098) gene. RESULTS: M.leprae bacillus could be detected in 22 (78.6%) of the 28 samples. 9 (45%) of the 20 biopsy samples and 6 (75%) of the 8 imprints were positive to TTC. 7 (35.5%) skin biopsy specimens and 5 (62.5%) imprints were positive to AGT, and 11 (55%) biopsies and 4 (50%) were positive to AGT. 11 (55%) skin biopsies and 4 (50%) imprints were positive to AT. 8(38%) skin biopsies and 5 (62.5%) imprints were positive to the Ml MntH gene. In the MB group, the microsatellites detected the bacillus in 78.5% of the samples, and the Ml MntH gene in 57.1% of the samples, independent of the clinical material. In the PB group 55.5% of samples were positive to the microsatellite primers, while 22.2% were positive to the Ml MntH gene. CONCLUSIONS: These results show that both the specific regions of microsatellites, as well as the Ml MntH gene fragment can be useful tools for detecting the M. leprae DNA by PCR in frozen skin biopsy samples and filter paper biopsy imprintsCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)(FAEPA) Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto - Universidade de São Paulo (USP) - Fundação de Apoio ao Ensino, Pesquisa e Assistênci

    Optimality Clue for Graph Coloring Problem

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    In this paper, we present a new approach which qualifies or not a solution found by a heuristic as a potential optimal solution. Our approach is based on the following observation: for a minimization problem, the number of admissible solutions decreases with the value of the objective function. For the Graph Coloring Problem (GCP), we confirm this observation and present a new way to prove optimality. This proof is based on the counting of the number of different k-colorings and the number of independent sets of a given graph G. Exact solutions counting problems are difficult problems (\#P-complete). However, we show that, using only randomized heuristics, it is possible to define an estimation of the upper bound of the number of k-colorings. This estimate has been calibrated on a large benchmark of graph instances for which the exact number of optimal k-colorings is known. Our approach, called optimality clue, build a sample of k-colorings of a given graph by running many times one randomized heuristic on the same graph instance. We use the evolutionary algorithm HEAD [Moalic et Gondran, 2018], which is one of the most efficient heuristic for GCP. Optimality clue matches with the standard definition of optimality on a wide number of instances of DIMACS and RBCII benchmarks where the optimality is known. Then, we show the clue of optimality for another set of graph instances. Optimality Metaheuristics Near-optimal
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