86 research outputs found

    A Mismatch-Based Model for Memory Reconsolidation and Extinction in Attractor Networks

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    The processes of memory reconsolidation and extinction have received increasing attention in recent experimental research, as their potential clinical applications begin to be uncovered. A number of studies suggest that amnestic drugs injected after reexposure to a learning context can disrupt either of the two processes, depending on the behavioral protocol employed. Hypothesizing that reconsolidation represents updating of a memory trace in the hippocampus, while extinction represents formation of a new trace, we have built a neural network model in which either simple retrieval, reconsolidation or extinction of a stored attractor can occur upon contextual reexposure, depending on the similarity between the representations of the original learning and reexposure sessions. This is achieved by assuming that independent mechanisms mediate Hebbian-like synaptic strengthening and mismatch-driven labilization of synaptic changes, with protein synthesis inhibition preferentially affecting the former. Our framework provides a unified mechanistic explanation for experimental data showing (a) the effect of reexposure duration on the occurrence of reconsolidation or extinction and (b) the requirement of memory updating during reexposure to drive reconsolidation

    The flora and vegetation of rocky outcrops in three municipalities in the northern region of Ceará, Brazil: phytosociological characterization

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    Veja material suplementar em <https://doi.org/10.6084/m9.figshare.5915233.v2O presente estudo teve como objetivo identificar a flora e a vegetação dos afloramentos rochosos isolados e de baixa altitude (lajedos), na vegetação de Caatinga Arbustiva Aberta, que se encontram nos municípios de Sobral, Groaíras e Santa Quitéria, no estado do Ceará, Brasil e propor uma classificação fitossociológica para estas comunidades xerófilas. Foram definidas cinco áreas de coleta de dados com elevada proporção de rochas expostas (> 80%) onde as excursões de campo decorreram em março de 2014 e 2015 (3º56’S e 40º23’W, 4º01’S e 40º05’W, 4º07’S e 40º08’W, 4º09’S e 40º09’W e 4º03’S e 40º00’W). No estudo da vegetação aplicou-se os métodos TWINSPAN (two-way indicator species analysis) e o clássico sigmatista de Braun-Blanquet. As áreas mínimas dos inventários fitossociológicos variaram de 8 a 16 m2. Foram coletadas as espécies vegetais que crescem em fissuras, fendas e ilhas de vegetação que se encontram em afloramentos rochosos. Foram registradas 88 espécies, distribuídas em 59 gêneros e 30 famílias botânicas. Fabaceae foi a família que se destacou em riqueza específica (20 spp.), seguida por Poaceae (dez spp.), Euphorbiaceae (sete spp.) e Convolvulaceae (seis spp.). Quanto ao endemismo foram registradas, em vegetação rupestre, 19 espécies endêmicas para o Brasil. Na análise fitossociológica da vegetação propôs-se estudar a comunidade de Pilosocereus gounellei (FA.C.Weber) Byles & Rowley e Encholirium spectabile Mart. ex Schult. & Schult.f. e a de Crateva tapia L. e Combretum leprosum Martinfo:eu-repo/semantics/publishedVersio

    Burnout Syndrome and alcohol consumption in prison employees

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    Objective: The aims of this study were to estimate the association between an at-risk drinking pattern and sociodemographic variables, and to compare the mean scores of the factors associated with the Burnout Syndrome, according to the alcohol consumption pattern in staff members from two Brazilian prisons. Methods: A cross-sectional study was developed with 339 participants (response rate = 63.8%). The instruments used were a sociodemographic questionnaire, the Alcohol Use Disorders Identification Test (AUDIT), and the Maslach Burnout Inventory – General Survey (MBI-GS). Results: The participants’ average age was 40.2 (SD = 8.8) years, and 81.0% were male. Among 78.5% of participants (95%CI 74.1 – 82.8) reported consuming alcoholic beverages. The prevalence of at-risk drinking behavior in the sample was 22.4% (95%CI 18.0 – 26.9), and of the Burnout Syndrome was 14.6% (95%CI 10.8 – 18.4). We observed a significant association between at-risk drinking behavior with gender, higher risk for men (OR = 7.32, p < 0.001), smoking, increased risk for smokers (OR = 2.77, p < 0.001), and religious practice, showing lower risks for religion practitioners (OR = 0.364, p < 0.001). We noticed significantly higher mean scores (p < 0.001) of emotional exhaustion and cynicism, and lower scores of professional achievement among individuals who reported consuming alcoholic beverages. Conclusion: Men who smoke were more likely to develop an at-risk drinking pattern, while religion is presented as a protective factor. Individuals who consume alcohol were more affected by the different factors of the Burnout Syndrome
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