4,757 research outputs found

    Thermodynamic entropy production in the dynamical Casimir effect

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    We address the question of entropy production in the context of the dynamical Casimir effect. Specifically, we consider a one-dimensional ideal cavity with one of its mirrors describing a prescribed trajectory. Inside the cavity we have a scalar quantum field and we ask about the changes in the thermodynamic entropy of the field induced by the non-trivial boundary conditions imposed by the moving mirror. By employing an effective Hamiltonian approach, we compute the entropy production and show that it scales with the number of particles created in the short-time limit. Moreover, such approach allows us to demonstrate that this entropy is directly related to the developments of quantum coherences in the mode basis of the field. A distinct approach, based on the time evolution of Gaussian states, allows us to study the long-time limit of the entropy production in single mode of the field. This results in a relation between the thermodynamic entropy production in the field mode with the entanglement between the considered mode and all the other modes. In this way, we link the entropy production in the field due to the dynamical Casimir effect with two fundamental features of quantum mechanics, coherence and entanglement.Comment: 11 pages, 1 figure, comments are welcom

    Finding Software Vulnerabilities in Open-Source C Projects via Bounded Model Checking

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    Computer-based systems have solved several domain problems, including industrial, military, education, and wearable. Nevertheless, such arrangements need high-quality software to guarantee security and safety as both are mandatory for modern software products. We advocate that bounded model-checking techniques can efficiently detect vulnerabilities in general software systems. However, such an approach struggles to scale up and verify extensive code bases. Consequently, we have developed and evaluated a methodology to verify large software systems using a state-of-the-art bounded model checker. In particular, we pre-process input source-code files and guide the respective model checker to explore them systematically. Moreover, the proposed scheme includes a function-wise prioritization strategy, which readily provides results for code entities according to a scale of importance. Experimental results using a real implementation of the proposed methodology show that it can efficiently verify large software systems. Besides, it presented low peak memory allocation when executed. We have evaluated our approach by verifying twelve popular open-source C projects, where we have found real software vulnerabilities that their developers confirmed.Comment: 27 pages, submitted to STTT journa

    Desenvolvimento de uma Aplicação para Classificação de Estruturas Cerebrais a partir de Imagens de Ressonância Magnética

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    Propomos uma metodologia para segmentação e classificação de três principais estruturas cerebrais em imagens de Ressonância Magnética. O trabalho foi dividido em quatro etapas para sua execução: alinhamento de imagens, separação de sub-imagens, extração de características e utilização de técnicas de inteligência artificial. Até o presente momento somente as três primeiras etapas foram executadas completament

    Contribution for the phytochemical studies of Ageratum fastigiatum

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    Organic extracts from leaves plus branches plus inflorescences of Ageratum fastigiatum (Gardner) R. M. King & H. Rob., Asteraceae, were fractionated through classic chromatography. The steroids stigmasterol, chondrillasterol and campesterol were isolated from hexane extract. The triterpenes lupeol, taraxasterol, α-amyrin, β-amyrin, pseudotaraxasterol, lupeol acetate and α-amyrin acetate were isolated from ethyl acetate extract. Steroids and triterpenes were identified by GC-MS. The coumarin ayapin was isolated from ethanol extract and identified by NMR. Essential oils of the fresh leaves and fresh inflorescences were obtained by hydrodistillation and analyzed for GC-MS. The main components in both essential oils were α-pinene, limonene and germacrene D.FAPEMI

    Identification by MALDI-TOF MS of Sporothrix brasiliensis isolated from a subconjunctival infiltrative lesion in an immunocompetent patient

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    Sporotrichosis is a globally distributed subcutaneous fungal infection caused by dimorphic fungi belonging to the Sporothrix species complex that affects the skin of limbs predominantly, but not exclusively. A rare case of ocular sporotrichosis in an immunocompetent Brazilian patient from the countryside of Rio de Janeiro State is reported. A 68-year-old woman presented with a subconjunctival infiltrative lesion in the right eye with pre-auricular lymphadenopathy of onset 4 months ago that evolved to suppurative nodular lesions on the eyelids. Conjunctival secretion was evaluated by histopathological examination and inoculated on Sabouraud Dextrose Agar (SDA). Histopathology showed oval bodies within giant cells and other mononucleated histiocytes. Fungus grown on SDA was identified as Sporothrix sp. by morphological observations. The isolated strain was finally identified by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) associated with an in-house database enriched with reference Sporothrix complex spectra. The strain presented a MALDI spectrum with the ion peaks of the molecular mass profile of S. brasiliensis. The patient was adequately treated with amphotericin B subsequently replaced by itraconazole. Due to scars left by the suppurative process, the patient presented poor final visual acuity. The present work presents an overview of ocular sporotrichosis and discusses the diagnostic difficulty that can lead to visual sequelae in these cases.Financial support for this work by Fundação de Amparo à Pesquisa do Rio de Janeiro [FAPERJ] (Grants: INST E-26/010.001784/2016; JCNE E-26/203.301/2017), by Conselho Nacional de Desenvolvimento Científico e Tecnológico [CNPq] (Grant Proc. 409227/2016-1). This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES). MALDI-TOF MS analyses were partially developed using equipment funded by CONICYT/Chile through the project Fondequip EQM160054 2016. The Universidad de La Frontera (Temuco, Chile) partially funded this work through the Project DIUFRO PIA19-0001. Furthermore, this study was also supported by FCT under the scope of the strategic funding of UID/BIO/04469/2019 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio

    Lack of association of indoleamine 2,3-dioxygenase polymorphisms with interferon-alpha-related depression in hepatitis C

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    Background: Major depression is a frequent adverse effect of interferon-alpha (IFN-alpha) therapy. Although the indoleamine 2,3-dioxygenase (IDO) enzyme seems to be involved in the pathophysiology of IFN-alpha-induced depression, no pharmacogenetic study has investigated Whether variation in the IDO gene modifies vulnerability to this adverse effect.Methods: A cross-sectional study assessing 277 hepatitis C patients recruited in two specialized outpatient clinics of Brazil. They were interviewed with the Mini International Neuropsychiatric Interview (MINI) approximately 1 month after the end of IFN-alpha plus ribavirin therapy. Genomic DNA of individuals was extracted from venous blood. Three IDO single-nucleotide polymorphisms (SNPs) were genotyped (rs3824259; rs10089084 and rs35099072).Results: MINI indicated that 21.3% of the sample met criteria for a major depressive episode during the course of IFN-alpha therapy. No association with the diagnosis of a major depressive episode during the course of IFN-alpha therapy was observed genotype or allele-wise (p > 0.05). Current major depression and/or current anxiety disorder was significantly associated with IFN-alpha-related depression (p 0.05).Conclusions: Our results suggest no influence of the variants in the IDO gene and the diagnosis of interferon-alpha-related depression in the Brazilian population. Interferon-alpha-related depression may impose persistent psychopathology on at least 15% of the depressed patients even 2 years after antiviral therapy termination. the cross-sectional design is a limitation of our study, predisposing memory bias. Prospective pharmacogenetic studies are warranted to continue investigation of the impact of IDO polymorphisms on the development of IFN-alpha-induced depression. (C) 2011 Elsevier Inc. All rights reserved.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Univ Fed Bahia, Sch Med, Dept Neurosci & Mental Hlth, BR-41170290 Salvador, BA, BrazilUniv Fed Bahia, Univ Hosp, Psychiat Serv, BR-41170290 Salvador, BA, BrazilUniversidade Federal de São Paulo, Sch Med, Dept Psychiat, São Paulo, BrazilUniversidade Federal de São Paulo, Sch Med, LiNC, São Paulo, BrazilUniversidade Federal de São Paulo, Sch Med, Inst Psychiat, São Paulo, BrazilUniversidade Federal de São Paulo, Sch Med, Dept Psychobiol, São Paulo, BrazilUniv Fed Bahia, Sch Med, Dept Gastroenterol, BR-41170290 Salvador, BA, BrazilUniversidade Federal de São Paulo, Sch Med, Hepatitis Unit, São Paulo, BrazilUniversidade Federal de São Paulo, Sch Med, Hosp São Paulo, São Paulo, BrazilHarvard Univ, Sch Publ Hlth, Dept Soc Human Dev & Hlth, Cambridge, MA 02138 USAUniversidade Federal de São Paulo, Sch Med, Dept Psychiat, São Paulo, BrazilUniversidade Federal de São Paulo, Sch Med, LiNC, São Paulo, BrazilUniversidade Federal de São Paulo, Sch Med, Inst Psychiat, São Paulo, BrazilUniversidade Federal de São Paulo, Sch Med, Dept Psychobiol, São Paulo, BrazilUniversidade Federal de São Paulo, Sch Med, Hepatitis Unit, São Paulo, BrazilUniversidade Federal de São Paulo, Sch Med, Hosp São Paulo, São Paulo, BrazilCNPq: 471592/2008-0CNPq: 142262/2008-0Web of Scienc

    Orchidaceae no município de Vitória da Conquista, Bahia: lista de espécies e similaridade florística entre áreas da Bahia e Minas Gerais

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    Here we present a survey of Orchidaceae from Vitória da Conquista, Brazil and an analysis of the floristic similarity among ten areas in Bahia and Minas Gerais. Fourty-four species of orchids were found in the municipality.  Among the species found, two are new occurrences for the Northeast region of Brazil, Acianthera panduripetala and Specklinia hymenantha, and one is a new occurrence for the state of Bahia, Pabstiella seriata. Analyzes were conducted using the UPGMA algorithm, Jaccard and Dice coefficient and Correspondence Analysis. The cluster analysis revealed low similarity rates, except for Serra Negra + Ibitipoca State Park. Two groups were formed: one group of dry forest areas and another group encompassing the Rupestrian Fields and Ombrophilous Forest areas of the two states. The results suggest that the areas of the same phytophysiognomy are more related to each other than to the vegetation of the same state.Se presenta el levantamiento de las Orchidaceae de Vitória da Conquista, Brasil, y un análisis de similitud florística entre diez áreas de Bahia y Minas Gerais. Se encontraron en el municipio un total de 44 especies de orquídeas, con dos nuevos registros para el nordeste brasileño, Acianthera panduripetala y Specklinia hymenantha, además de un nuevo registro para el estado de Bahia, Pabstiella seriata. Se realizaron análisis utilizando el algoritmo UPGMA, coeficiente de Jaccard y Dice, y Análisis de Correspondencia. El análisis de agrupamiento reveló bajos índices de similitud, excepto para Serra Negra + Parque Estadual do Ibitipoca. Dos grupos fueron formados: Uno de áreas de Bosques secos y otro que incluye las áreas de Campos Rupestres y de Bosques Ombrófilos de los dos estados. Los resultados sugieren que las áreas con la misma fitofisionomía están más relacionadas entre sí, que con la vegetación del mismo estadoAqui, apresentamos o levantamento das Orchidaceae de Vitória da Conquista, Brasil, e uma análise da similaridade florística entre dez áreas da Bahia e Minas Gerais. Foram encontradas no município 44 espécies de orquídeas, sendo duas novas ocorrências para o Nordeste brasileiro, Acianthera panduripetala e Specklinia hymenantha, além de uma nova ocorrência para o estado da Bahia, Pabstiella seriata. Foram conduzidas análises utilizando o algoritmo UPGMA, coeficiente de Jaccard e Dice, e análise de correspondência. A análise de agrupamento revelou baixos índices de similaridade, exceto para Serra Negra + Parque Estadual do Ibitipoca. Dois grupos se formaram: um de áreas de Florestas Secas e outro grupo que inclui as áreas de Campos Rupestres e de Floresta Ombrófila dos dois estados. Os resultados sugerem que as áreas de mesma fitofisionomia estão mais relacionadas entre si do que com a vegetação do mesmo estado
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