7,228 research outputs found

    Video browsing interfaces and applications: a review

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    We present a comprehensive review of the state of the art in video browsing and retrieval systems, with special emphasis on interfaces and applications. There has been a significant increase in activity (e.g., storage, retrieval, and sharing) employing video data in the past decade, both for personal and professional use. The ever-growing amount of video content available for human consumption and the inherent characteristics of video data—which, if presented in its raw format, is rather unwieldy and costly—have become driving forces for the development of more effective solutions to present video contents and allow rich user interaction. As a result, there are many contemporary research efforts toward developing better video browsing solutions, which we summarize. We review more than 40 different video browsing and retrieval interfaces and classify them into three groups: applications that use video-player-like interaction, video retrieval applications, and browsing solutions based on video surrogates. For each category, we present a summary of existing work, highlight the technical aspects of each solution, and compare them against each other

    Role of microRNAs in the age-associated decline of pancreatic beta cell function in rat islets

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    This is a freely-available open access publication. Please cite the published version which is available via the DOI link in this record.AIMS/HYPOTHESIS: Ageing can lead to reduced insulin sensitivity and loss of pancreatic beta cell function, predisposing individuals to the development of diabetes. The aim of this study was to assess the contribution of microRNAs (miRNAs) to age-associated beta cell dysfunction. METHODS: The global mRNA and miRNA profiles of 3- and 12-month-old rat islets were collected by microarray. The functional impact of age-associated differences in miRNA expression was investigated by mimicking the observed changes in primary beta cells from young animals. RESULTS: Beta cells from 12-month-old rats retained normal insulin content and secretion, but failed to proliferate in response to mitotic stimuli. The islets of these animals displayed modifications at the level of several miRNAs, including upregulation of miR-34a, miR-124a and miR-383, and downregulation of miR-130b and miR-181a. Computational analysis of the transcriptomic modifications observed in the islets of 12-month-old rats revealed that the differentially expressed genes were enriched for miR-34a and miR-181a targets. Indeed, the induction of miR-34a and reduction of miR-181a in the islets of young animals mimicked the impaired beta cell proliferation observed in old animals. mRNA coding for alpha-type platelet-derived growth factor receptor, which is critical for compensatory beta cell mass expansion, is directly inhibited by miR34a and is likely to be at least partly responsible for the effects of this miRNA. CONCLUSIONS/INTERPRETATION: Changes in the level of specific miRNAs that occur during ageing affect the proliferative capacity of beta cells. This might reduce their ability to expand under conditions of increased insulin demand, favouring the development of type 2 diabetes.Swiss National Science FoundationFondation Francophone pour la Recherche sur le DiabèteWellcome Trust Senior Investigator AwardMRC Programme GrantRoyal Society Wolfson Research Merit AwardWellcome Trust project gran

    Can optical spectroscopy directly elucidate the ground state of C20?

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    The optical response of the lowest energy members of the C20 family is calculated using time-dependent density functional theory within a real-space, real-time scheme. Significant differences are found among the spectra of the different isomers, and thus we propose optical spectroscopy as a tool for experimental investigation of the structure of these important clusters.Comment: 11 pages, 2 figures. To be published in J. Chem. Phy

    Diversidade de tuviras comercializadas como iscas vivas pelas comunidades do Porto da Manga e Codrasa, Corumbá, MS.

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    A pesca é uma das principais atividades econômicas no Pantanal do Mato Grosso do Sul. Na década de 1990, o setor turístico pesqueiro cresceu expressivamente, gerando demandas por serviços especializados, como a captura de iscas vivas. Desde então, diversas comunidades de pescadores profissionais artesanais têm sua principal fonte de renda baseada na captura de iscas vivas destinadas principalmente ao setor turístico pesqueiro. O principal produto são as tuviras (Gymnotiformes), representando mais de 70% da captura anual de iscas vivas. Entretanto, nesta região não há conhecimento sobre a diversidade de espécies da Ordem Gymnotiformes que são exploradas comercialmente. Em outras palavras, não se sabe quantas espécies de tuviras são utilizadas como iscas vivas. Assim, esta pesquisa visou responder a essa dúvida. Adquirimos amostras a partir dos peixes estocados para venda pelas comunidades do Porto da Manga e da Codrasa, no município de Corumbá, MS. Utilizando iniciadores de tetranucleotídeos repetidos (GGAC)4 e empregando a técnica SPAR (Single Primer Amplification Reaction), encontramos quatro padrões de bandas, correspondentes às espécies Gymnotus paraguensis, G. pantanal, G. sylvius e G. inaequilabiatus. Assim, agora sabemos que esses pescadores exploram comercialmente quatro espécies de tuviras e não duas como constam na legislação vigente. Tal conhecimento pode auxiliar na construção de estratégias de conservação e uso sustentável deste recurso natural no Pantanal.bitstream/item/79844/1/BP120.pd

    Processing The Interspecies Quorum-Sensing Signal Autoinducer-2 (AI-2) Characterization Of Phospho-(S)-4,5-Dihydroxy-2,3-Pentanedione Isomerization By LsrG Protein

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    The molecule (S)-4,5-dihydroxy-2,3-pentanedione (DPD) is produced by many different species of bacteria and is the precursor of the signal molecule autoinducer-2 (AI-2). AI-2 mediates interspecies communication and facilitates regulation of bacterial behaviors such as biofilm formation and virulence. A variety of bacterial species have the ability to sequester and process the AI-2 present in their environment, thereby interfering with the cell-cell communication of other bacteria. This process involves the AI-2-regulated lsr operon, comprised of the Lsr transport system that facilitates uptake of the signal, a kinase that phosphorylates the signal to phospho-DPD (P-DPD), and enzymes (like LsrG) that are responsible for processing the phosphorylated signal. Because P-DPD is the intracellular inducer of the lsr operon, enzymes involved in P-DPD processing impact the levels of Lsr expression. Here we show that LsrG catalyzes isomerization of P-DPD into 3,4,4-trihydroxy-2-pentanone-5-phosphate. We present the crystal structure of LsrG, identify potential catalytic residues, and determine which of these residues affects P-DPD processing in vivo and in vitro. We also show that an lsrG deletion mutant accumulates at least 10 times more P-DPD than wild type cells. Consistent with this result, we find that the lsrG mutant has increased expression of the lsr operon and an altered profile of AI-2 accumulation and removal. Understanding of the biochemical mechanisms employed by bacteria to quench signaling of other species can be of great utility in the development of therapies to control bacterial behavior

    Procedimentos para coleta e preparo de perfis de solos preservados (macromonolitos).

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    Neste trabalho, serão descritos os procedimentos de seleção, coleta e preparo de monolitos de solos em tamanho natural, visando à construção de uma coleção. Aspectos principais sobre a preservação, transporte, exposição e custos também serão abordados. Vale destacar que esta publicação consiste em uma metodologia de coleta, preparo e exposição de macromonolitos diferente daquela apresentada por Pedron e Dalmolin (2010). Assim sendo,oferece ao usuário uma alternativa de uso de um ou outro método, no caso de um deles não apresentar sucesso em determinada classe de solo.bitstream/item/58011/1/doc134-2011-preparo-macromonolito.pd

    Demonstration project on epilepsy in Brazil - Outcome assessment

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    Purpose: To assess the outcome of patients with epilepsy treated at primary care health units under the framework of the demonstration project on epilepsy in Brazil, part of the WHO/ILAE/IBE Global Campaign Against Epilepsy. Method. We assessed the outcome of patients treated at four primary health units. The staff of the health units underwent information training in epilepsy. The outcome assessment was based on: 1) reduction of seizure frequency, 2) subjective perception from the patient's and the physician's point of view, 3) reduction of absenteeism, 4) social integration (school and work), and 5) sense of independence. Results: A total of 181 patients (93 women - 51%) with a mean age of 38 (range from 2 to 86) years were studied. The mean follow-up was 26 months (range from 1 to 38 months, 11 patients had follow-up of less than 12 months). Seizure frequency was assessed based on a score system, ranging from 0 (no seizure in the previous 24 months) to 7 (> 10 seizure/day). The baseline median seizure-frequency score was 3 (one to three seizures per month). At the end of the study the median seizure-frequency score was 1 (one to three seizures per year). The patients' and relatives' opinions were that in the majority (59%) the health status had improved a lot, some (19%) had improved a little, 20% experienced no change and in 2% the health status was worse. With regard to absenteeism, social integration and sense of independence, there were some modest improvements only. Discussion: The development of a model of epilepsy treatment at primary health level based on the existing health system, with strategic measures centred on the health care providers and the community, has proved to be effective providing important reductions in seizure frequency, as well as in general well being. This model can be applied nationwide, as the key elements already exist provided that strategic measures are put forward in accordance with local health providers and managers
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