341 research outputs found

    Fuzzy automata as coalgebras

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    The coalgebraic method is of great significance to research in process algebra, modal logic, object-oriented design and component-based software engineering. In recent years, fuzzy control has been widely used in many fields, such as handwriting recognition and the control of robots or air conditioners. It is then an interesting topic to analyze the behavior of fuzzy automata from a coalgebraic point of view. This paper models different types of fuzzy automata as coalgebras with a monad structure capturing fuzzy behavior. Based on the coalgebraic models, we can define a notion of fuzzy language and consider several versions of bisimulation for fuzzy automata. A group of combinators is defined to compose fuzzy automata of two branches: state transition and output function. A case study illustrates the coalgebraic models proposed and their composition.This work has been supported by the Guangdong Science and Technology Department (Grant No. 2018B010107004) and the National Natural Science Foundation of China under grant No. 61772038, 61532019 and 61272160. L.S.B. was supported by the ERDF—European Regional Development Fund through the Operational Programme for Competitiveness and InternationalisationCOMPETE 2020 Programme and by National Funds through the Portuguese funding agency, FCT, within project KLEE - POCI-01-0145-FEDER-030947

    Dietary availability patterns of the brazilian macro-regions

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    <p>Abstract</p> <p>Introduction</p> <p>Epidemiological studies have raised concerns about the role of dietary patterns on the risk of chronic diseases and also in the formulation of better informed nutrition policies.</p> <p>Objective</p> <p>The development of a dietary availability patterns according to geographic regions in Brazil.</p> <p>Methodology</p> <p>The 2002-2003 Brazilian Household Budget Survey was conducted in 48,470 households. Dietary availability patterns were identified by Principal Component Analysis using as a unit of analysis the survey's Primary Sampling Units (PSUs) and purchased amounts for 21 food groups. Each of the extracted dietary availability patterns was regressed on socioeconomics categories.</p> <p>Results</p> <p>There were no differences in dietary availability patterns between urban and rural areas. In all regions, a rice and beans pattern was identified. This pattern explained 15% to 28% of the variance dependent on the region of the country. In South, Southeast and Midwest regions, a mixed pattern including at least 10 food groups explaining 8% to 16% of the variance. In the North region (Amazon forest included) the first pattern was based on fish and nuts and then it was designed as regional pattern. In multiple linear regression the rice and beans pattern was associated with the presence of adolescents in the households, except for North region, whereas the presence of adolescents was associated with the Regional pattern. A mixed patterns were associated with a higher income and education (p < 0.05), except in the South region.</p> <p>Conclusion</p> <p>The rice and beans and regional dietary availability patterns, both considered healthy eating patterns are still important in the country. Brazil has taken many actions to improve nutrition as part of their public health policies, the data of the Household Budget Survey could help to recognize the different food choices in the large regions of the country.</p

    Protein kinase C activation disrupts epithelial apical junctions via ROCK-II dependent stimulation of actomyosin contractility

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    <p>Abstract</p> <p>Background</p> <p>Disruption of epithelial cell-cell adhesions represents an early and important stage in tumor metastasis. This process can be modeled <it>in vitro </it>by exposing cells to chemical tumor promoters, phorbol esters and octylindolactam-V (OI-V), known to activate protein kinase C (PKC). However, molecular events mediating PKC-dependent disruption of epithelial cell-cell contact remain poorly understood. In the present study we investigate mechanisms by which PKC activation induces disassembly of tight junctions (TJs) and adherens junctions (AJs) in a model pancreatic epithelium.</p> <p>Results</p> <p>Exposure of HPAF-II human pancreatic adenocarcinoma cell monolayers to either OI-V or 12-O-tetradecanoylphorbol-13-acetate caused rapid disruption and internalization of AJs and TJs. Activity of classical PKC isoenzymes was responsible for the loss of cell-cell contacts which was accompanied by cell rounding, phosphorylation and relocalization of the F-actin motor nonmuscle myosin (NM) II. The OI-V-induced disruption of AJs and TJs was prevented by either pharmacological inhibition of NM II with blebbistatin or by siRNA-mediated downregulation of NM IIA. Furthermore, AJ/TJ disassembly was attenuated by inhibition of Rho-associated kinase (ROCK) II, but was insensitive to blockage of MLCK, calmodulin, ERK1/2, caspases and RhoA GTPase.</p> <p>Conclusion</p> <p>Our data suggest that stimulation of PKC disrupts epithelial apical junctions via ROCK-II dependent activation of NM II, which increases contractility of perijunctional actin filaments. This mechanism is likely to be important for cancer cell dissociation and tumor metastasis.</p

    piRNAs mediate posttranscriptional retroelement silencing and localization to pi-bodies in the Drosophila germline

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    Nuage, a well-conserved perinuclear organelle found in germline cells, is thought to mediate retroelement repression in Drosophila melanogaster by regulating the production of Piwi-interacting RNAs (piRNAs). In this study, we present evidence that the nuage–piRNA pathway components can be found in cytoplasmic foci that also contain retroelement transcripts, antisense piRNAs, and proteins involved in messenger RNA (mRNA) degradation. These mRNA degradation proteins, decapping protein 1/2 (DCP1/2), Me31B (maternal expression at 31B), and pacman (PCM), are normally thought of as components of processing bodies. In spindle-E (spn-E) and aubergine (aub) mutants that lack piRNA production, piRNA pathway proteins no longer overlap the mRNA degradation proteins. Concomitantly, spn-E and aub mutant ovaries show an accumulation of full-length retroelement transcripts and prolonged stabilization of HeT-A mRNA, supporting the role of piRNAs in mediating posttranscriptional retroelement silencing. HeT-A mRNA is derepressed in mRNA degradation mutants twin, dcp1, and ski3, indicating that these enzymes also aid in removing full-length transcripts and/or decay intermediates

    The development and psychometric properties of the Arabic version of the child oral health impact profile-short form (COHIP- SF 19)

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    BACKGROUND: This study aims to cross-culturally adapt the original English-language COHIP-SF 19 to Arabic culture and to test its psychometric properties in a community sample. METHODS: The Arabic COHIP-SF 19 was developed and its psychometric properties were examined in a population-based sample of 876 schoolchildren who were aged 12 years of age, in Benghazi, Libya. The Arabic COHIP-SF 19 was tested for its internal consistency, reproducibility, construct validity, factorial validity and floor as well as ceiling effects. A Mann-Whitney U test was used to compare the mean scores of COHIP-SF 19 by participants' caries status and self-reported oral health rating, satisfaction and treatment need. RESULTS: The Arabic COHIP-SF 19 was successfully and smoothly developed. It showed an acceptable level of equivalence to the original version. Overall, the internal consistency and reproducibility were acceptable to excellent, with a Cronbach's alpha of 0.84 and an intra-class correlation coefficient (ICC) of 0.76. All hypotheses predefined to test construct validity were confirmed. That is, children who had active dental caries, and who rated their oral health as poor, were not satisfied with their oral health or indicated the need of treatment had lower COHIP-SF 19 scores (P < 0.05). Floor or ceiling effects were not observed. The exploratory Factorial analysis suggested a 4-component solution and deletion of one item. CONCLUSION: The Arabic COHIP-SF 19 was successfully developed. The measure demonstrated satisfactory reliability and validity to estimate OHRQoL in a representative sample of 12-year-old schoolchildren
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