Faddeev-Jackiw formalism for a topological-like oscillator in planar dimensions

The problem of a harmonic oscillator coupling to an electromagnetic potential plus a topological-like (Chern-Simons) massive term, in two-dimensional space, is studied in the light of the symplectic formalism proposed by Faddeev and Jackiw for constrained systems.Comment: 17 pages, Latex file, to appear in Mod. Phys. Let.

Class of self-dual models in three dimensions

In the present paper we introduce a hierarquical class of self-dual models inthree dimensions, inspired in the original self-dual theory ofTowsend-Pilch-Nieuwenhuizen. The basic strategy is to explore the powerfulproperty of the duality transformations in order to generate a new field. Thegeneralized propagator can be written in terms of the primitive one (firstorder), and also the respective order and disorder correlation functions. Someconclusions about the ``charge screening'' and magnetic flux were established

Simultaneous analysis of 25 phenolic compounds in grape juice for HPLC: method validation and characterization of São Francisco Valley samples.

A HPLCmethod for simultaneous determination of 25 phenolic compounds in grape juicewas optimized, validated and applied in the characterization of juices produced in São Francisco Valley (SFV), Brazil. The performance characteristics of the method were established by assays with standard solutions of phenolic compounds, spiked and unspiked samples. Linearity,matrix effects, trueness, precision, detection and quantification limits were evaluated. Linearity was demonstrated in the concentration ranges tested for all phenolic compounds. Significant matrix effects were not identified for the studied compounds.Mean recoveries ranged from86.18 to 106.50%, demonstrating no lack of trueness. Precision of the method was confirmed for the 25 phenolic compounds, with acceptable repeatability relative standard deviations (from 0.71 to 9.24%) and within-reproducibility relative standard deviations (from1.34 to 9.26%) for unspiked and spiked samples. The theoretical limits of detection and quantification of themethod varied from 0.001 to 0.19 Mg mL-1 and 0.003 to 0.37 Mg mL-1, respectively. The results of the validation process showed that the proposed method is fitness for purpose. This method was able to identify simultaneously 25 phenolic compounds and had advantages such as low consumption of solvents and easy sample preparation. The phenolic profile of the grape juices from SFV varied according the grape cultivar. Phenolics of the anthocyanins and tannins class predominated in red grape juices, while in white grape juice phenolic acids and tannins were found at high concentrations

Symmetry transform in the Faddeev-Jackiw quantization of dual models

We study the presence of symmetry transformations in the Faddeev-Jackiw approach for constrained systems. Our analysis is based in the case of a particle submitted to a particular potential which depends on an arbitrary function. The method is implemented in a natural way and symmetry generators are identified. These symmetries permit us to obtain the absent elements of the sympletic matrix which complement the set of Dirac brackets of such a theory. The study developed here is applied in two different dual models. First, we discuss the case of a two-dimensional oscillator interacting with an electromagnetic potential described by a Chern-Simons term and second the Schwarz-Sen gauge theory, in order to obtain the complete set of non-null Dirac brackets and the correspondent Maxwell electromagnetic theory limit.Comment: 22 pages, RevTex file, no figur

Desenvolvimento de cartilha educativa sobre o uso de adoçantes artificiais

A busca por hábitos alimentares mais saudáveis, o controle do diabetes e o grande interesse em manter a boa forma, fez crescer nos últimos anos o uso de adoçantes artificiais como alternativas para substituir o açúcar. Entretanto, a ingestão excessiva destes adoçantes é prejudicial para a saúde, principalmente para gestantes. O presente estudo não condena e nem incentiva o uso de qualquer adoçante artificial, mas busca trazer orientações e advertências quanto ao seu uso e suas peculiaridades. Para isso, utilizou-se como ferramenta uma cartilha explicativa dos efeitos adversos e toxicológicos dos adoçantes Aspartame, Ciclamato de Sódio e Sacarina Sódica. Para esse trabalho, foram feitas buscas nas bases de dados PUBMED e SCIELO, limitando os artigos em idioma (língua inglesa e portuguesa) e ano de publicação (a partir de 2000), usando como palavras-chaves os termos: gestação, adoçantes artificiais, aspartame, ciclamato de sódio e sacarina sódica. O programa utilizado para a diagramação foi o CorelDRAW. Esta cartilha tem como objetivo orientar sobre o uso de adoçantes na alimentação, portanto, para sua elaboração foi desenvolvido um personagem para atrair o leitor, despertar o interesse pela leitura e auxiliar na compreensão da mensagem. Uma formiguinha por "entender" muito bem de sacarose, explica o conteúdo da cartilha, em cima de uma folha de papel. A cartilha inicia com a história do açúcar branco e a definição de adoçantes artificiais. Em seguida são mostradas as principais características dos adoçantes estudados, comparando-os entre si. Recomendações da ANVISA encontram-se ao longo do texto, assim como sugestões de como usá-los e substituí-los. A cartilha elaborada será distribuída após aplicação de questionário exploratório a gestantes que fazem parte do Programa de Estratégia da Família em três postos de atendimento da rede municipal de Volta Redonda. Após um mês um questionário de avaliação do produto será aplicado

Seroprevalence of Chikungunya Virus after Its Emergence in Brazil.

Chikungunya has had a substantial impact on public health because of the magnitude of its epidemics and its highly debilitating symptoms. We estimated the seroprevalence, proportion of symptomatic cases, and proportion of chronic form of disease after introduction of chikungunya virus (CHIKV) in 2 cities in Brazil. We conducted the population-based study through household interviews and serologic surveys during October-December 2015. In Feira de Santana, we conducted a serologic survey of 385 persons; 57.1% were CHIKV-positive. Among them, 32.7% reported symptoms, and 68.1% contracted chronic chikungunya disease. A similar survey in Riachão do Jacuípe included 446 persons; 45.7% were CHIKV-positive, 41.2% reported symptoms, and 75.0% contracted the chronic form. Our data confirm intense CHIKV transmission during the continuing epidemic. Chronic pain developed in a high proportion of patients. We recommend training health professionals in management of chronic pain, which will improve the quality of life of chikungunya-affected persons

BFFT formalism applied to the minimal chiral Schwinger model

We consider the minimal chiral Schwinger model, by embedding the gauge noninvariant formulation into a gauge theory following the Batalin-Fradkin-Fradkina-Tyutin point of view. Within the BFFT procedure, the second class constraints are converted into strongly involutive first-class ones, leading to an extended gauge invariant formulation. We also show that, like the standard chiral model, in the minimal chiral model the Wess-Zumino action can be obtained by performing a q-number gauge transformation into the effective gauge noninvariant action.Comment: 11 Latex pages. Revised version: New section and more references included. To appear in MPL