195 research outputs found

    Quantum equivalence between the self-dual and the Maxwell-Chern-Simons models nonlinearly coupled to U(1) scalar fields

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    The use of master actions to prove duality at quantum level becomes cumbersome if one of the dual fields interacts nonlinearly with other fields. This is the case of the theory considered here consisting of U(1) scalar fields coupled to a self-dual field through a linear and a quadratic term in the self-dual field. Integrating perturbatively over the scalar fields and deriving effective actions for the self-dual and the gauge field we are able to consistently neglect awkward extra terms generated via master action and establish quantum duality up to cubic terms in the coupling constant. The duality holds for the partition function and some correlation functions. The absence of ghosts imposes restrictions on the coupling with the scalar fields.Comment: 13 pages, no figure

    Fluctuation Dissipation Relation for a Langevin Model with Multiplicative Noise

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    A random multiplicative process with additive noise is described by a Langevin equation. We show that the fluctuation-dissipation relation is satisfied in the Langevin model, if the noise strength is not so strong.Comment: 11 pages, 6 figures, other comment

    Nonextensivity and multifractality in low-dimensional dissipative systems

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    Power-law sensitivity to initial conditions at the edge of chaos provides a natural relation between the scaling properties of the dynamics attractor and its degree of nonextensivity as prescribed in the generalized statistics recently introduced by one of us (C.T.) and characterized by the entropic index qq. We show that general scaling arguments imply that 1/(1q)=1/αmin1/αmax1/(1-q) = 1/\alpha_{min}-1/\alpha_{max}, where αmin\alpha_{min} and αmax\alpha_{max} are the extremes of the multifractal singularity spectrum f(α)f(\alpha) of the attractor. This relation is numerically checked to hold in standard one-dimensional dissipative maps. The above result sheds light on a long-standing puzzle concerning the relation between the entropic index qq and the underlying microscopic dynamics.Comment: 12 pages, TeX, 4 ps figure

    Silent polymorphisms in the RYR1 gene do not\ud modify the phenotype of the p.4898 I>T\ud pathogenic mutation in central core disease:\ud a case report

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    Background: Central core disease is a congenital myopathy, characterized by presence of central core-like areas in\ud muscle fibers. Patients have mild or moderate weakness, hypotonia and motor developmental delay. The disease is\ud caused by mutations in the human ryanodine receptor gene (RYR1), which encodes a calcium-release channel.\ud Since the RYR1 gene is huge, containing 106 exons, mutation screening has been limited to three ‘hot spots’, with\ud particular attention to the C-terminal region. Recent next- generation sequencing methods are now identifying\ud multiple numbers of variants in patients, in which interpretation and phenotype prevision is difficult.\ud Case presentation: In a Brazilian Caucasian family, clinical, histopathological and molecular analysis identified a\ud new case of central core disease in a 48-year female. Sanger sequencing of the C-terminal region of the RYR1\ud gene identified two different missense mutations: c.14256 A > C polymorphism in exon 98 and c.14693 T > C in\ud exon 102, which have already been described as pathogenic. Trans-position of the 2 mutations was confirmed\ud because patient’s daughter, mother and sister carried only the exon 98’s mutation, a synonymous variant that was\ud subsequently found in the frequency of 013–0,05 of alleles. Further next generation sequencing study of the whole\ud RYR1 gene in the patient revealed the presence of additional 5 common silent polymorphisms in homozygosis and\ud 8 polymorphisms in heterozygosis.\ud Conclusions: Considering that patient’s relatives showed no pathologic phenotype, and the phenotype presented\ud by the patient is within the range observed in other central core disease patients with the same mutation, it was\ud concluded that the c.14256 A > C polymorphism alone is not responsible for disease, and the associated additional\ud silent polymorphisms are not acting as modifiers of the primary pathogenic mutation in the affected patient. The\ud case described above illustrates the present reality where new methods for wide genome screening are becoming\ud more accessible and able to identify a great variety of mutations and polymorphisms of unknown function in\ud patients and their families.Fundação de Amparo a Pesquisa do Estado de São Paulo - Centro de Pesquisa, Inovação e Difusão (FAPESP-CEPID)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq-INCT)Associação Brasileira de Distrofia Muscular (ABDIM)CAPES-COFECU

    Microcausality and quantization of the fermionic Myers-Pospelov model

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    We study the fermionic sector of the Myers and Pospelov theory with a general background nn. The spacelike case without temporal component is well defined and no new ingredients came about, apart from the explicit Lorentz invariance violation. The lightlike case is ill defined and physically discarded. However, the other case where a nonvanishing temporal component of the background is present, the theory is physically consistent. We show that new modes appear as a consequence of higher time derivatives. We quantize the timelike theory and calculate the microcausality violation which turns out to occur near the light cone.Comment: 9 pages and 3 figures, new version accepted in EPJC, Volume 72, Issue 9, includes lee-wick review, microcausalit

    Atividade antibacteriana de Óleos Essenciais sobre Streptococcus mutans e Staphylococcus aureus

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    Este trabalho objetivou avaliar a ação antimicrobiana in vitro dos óleos essenciais de Ocimum basilicum (Manjericão Exótico), Thymus vulgaris (Tomilho Branco), e de Cinnamomum cassia (Canela da China) sobre cepas bacterianas de Streptococcus mutans (ATCC 25175) e Staphylococcus aureus (ATCC 25923). A atividade antibacteriana dos óleos essenciais foi determinada pela Concentração Inibitória Mínima (CIM) e a Concentração Bactericida Mínima (CBM) através da técnica de microdiluição e do esgotamento. Para a CIM, foram utilizadas placas de 96 poços e inseriu-se 100µL de caldo BHI, 100µL da diluição dos óleos essenciais no primeiro poço e 10µL da suspensão bacteriana (1,5x106 microrganismos/mL). Realizou-se a diluição seriada partindo-se da concentração inicial de 8% até 0,0625%. A CIM correspondeu à última diluição na qual não foi verificada a presença de bactérias. Para obter a CBM, realizou-se a semeadura em Ágar Miller-Hinton das diluições correspondentes a CIM, 2CIM e 4CIM. As placas foram incubadas a 37º C em estufa bacteriológica por 24 horas. Os testes foram realizados em triplicata tendo a clorexidina como controle positivo. Para S. aureus (ATCC 25923) a CIM e CBM dos óleos essenciais de C. cassia, O. basilicum e T. vulgaris foram 0,0625%, 4% e 0,0625%, respectivamente. Para S. mutans a CIM e a CBM dos óleos essenciais de C. cassia e T. vulgaris foram 0,125% e 0,25%, respectivamente. Já a CIM do O. basilicum foi 4% e não apresentou ação bactericida. Conclui-se que os óleos essenciais avaliados apresentaram ação antibacteriana frente a cepas de S. mutans e S. aureus, sendo que os menores valores de CIM e de CBM foram provenientes dos óleos de C. cassia e T. vulgaris1621372377The aim of this study is to evaluate the in vitro antimicrobial activity of essential oils of Ocimum basilicum (basil), Thymus vulgaris (thyme) and Cinnamomum cassia (Chinese cinnamon) against strains of Streptococcus mutans (ATCC 25175) and Staphylococcus aureus (ATCC 25923). The antibacterial activity of the essential oils was determined by Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC). The MIC was obtained by the microdilution technique using 96-well microplates, in which we inserted: 100µL of Brain Heart Infusion broth at double concentration, 100µL of the dilution of the essential oils and 10µL of bacterial suspension (1.5 x 106 organisms / mL). The products were diluted from the initial concentration of 8% up to 0.0625%. The MIC corresponded to the last dilution in which there was no presence of bacteria or turbidity in the culture medium. The MBC was obtained by seeding, in Mueller-Hinton agar, 10µL aliquots of dilutions corresponding to the MIC and the two immediately preceding ones (2MIC and 4MIC). The plates were incubated at 37°C in a bacteriological incubator for 24 hours. The tests were performed in triplicate, and 2% Chlorhexidine Digluconate was the control product. For S. aureus, the MIC and MBC of the essential oils of C. cassia, O. basilicum and T. vulgaris were 0.0625%, 0.0625% and 4%, respectively. For S. mutans, the MIC and MBC of the essential oils of C. cassia and T. vulgaris were 0.125% and 0.25%, respectively. The MIC of O. basilicum against S. mutans was 4% and the essential oil showed no bactericidal action. Chlorhexidine Digluconate presented antibacterial activity against all organisms. The evaluated essential oils presented antibacterial activity against the strains of S. mutans and S. aureus, and we highlight the essential oils from C. cassia and T. vulgaris with the lowest MIC and MBCsem informaçã

    Nemaline Myopathy in Brazilian Patients: Molecular and Clinical Characterization

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    Nemaline myopathy (NM), a structural congenital myopathy, presents a significant clinical and genetic heterogeneity. Here, we compiled molecular and clinical data of 30 Brazilian patients from 25 unrelated families. Next-generation sequencing was able to genetically classify all patients: sixteen families (64%) with mutation in NEB, five (20%) in ACTA1, two (8%) in KLHL40, and one in TPM2 (4%) and TPM3 (4%). In the NEB-related families, 25 different variants, 11 of them novel, were identified; splice site (10/25) and frame shift (9/25) mutations were the most common. Mutation c.24579 G>C was recurrent in three unrelated patients from the same region, suggesting a common ancestor. Clinically, the “typical” form was the more frequent and caused by mutations in the different NM genes. Phenotypic heterogeneity was observed among patients with mutations in the same gene. Respiratory involvement was very common and often out of proportion with limb weakness. Muscle MRI patterns showed variability within the forms and genes, which was related to the severity of the weakness. Considering the high frequency of NEB mutations and the complexity of this gene, NGS tools should be combined with CNV identification, especially in patients with a likely non-identified second mutation
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