Braz Dent J

This study investigated the presence of the black-pigmented bacteria Prevotella nigrescens and Prevotella intermedia, the non-black-pigmented bacteria Actinomyces spp and particularly the cariogenic pathogen Streptococcus mutans in the dental biofilms of patients with or without black extrinsic tooth stains, using the multiplex polymerase chain reaction (PCR) technique. Analysis of the dental biofilms of patients with (n=26) or without (n=26) black tooth stains was performed using duplex PCR for the 16S ribosomal RNA gene (P. nigrescens, P. intermedia, Actinomyces spp) and glucosyltransferase-I gene for S. mutans. P. nigrescens and S. mutans were the most frequent bacteria detected in both groups. The least frequently detected were P. intermedia and Actinomyces spp. The similar bacterial composition of dental biofilms of black tooth stains and healthy tooth surfaces indicates that black tooth stains are not free of cariogenic bacteria.CC999999/ImCDC/Intramural CDC HHSUnited States/2022-05-20T00:00:00Z23306233PMC91213651148

Numerical symmetrization of state of identical particles

The method of numerical symmetrization of state of identical particles proposed by us before is clarified and discussed.Comment: Talk presented by O.Utyuzh at XXXVI International Symposium on Multiparticle Dynamics, September 2-8, 2006, Paraty (RJ), Brazil; minor corrections, to be published in Braz. J. Phys. (2007

Braz J Otorhinolaryngol

IntroductionEarlier studies have demonstrated an auditory effect of lead exposure in children,but information on the effects of low chronic exposures needs to be further elucidated.ObjectiveTo investigate the effect of low chronic exposures of the auditory system in childrenwith a history of low blood lead levels, using an auditory electrophysiological test.MethodsContemporary cross-sectional cohort. Study participants underwent tympanometry, pure tone and speech audiometry, transient evoked otoacoustic emissions, and brainstem auditory evoked potentials, with blood lead monitoring over a period of 35.5 months. The study included 130 children, with ages ranging from 18 months to 14 years, 5 months (mean age 6years, 8 months \uc2\ub1 3 years, 2 months).ResultsThe mean time-integrated cumulative blood lead index was 12 g/dL (SD \uc2\ub1 5.7, range:2.433). All participants had hearing thresholds equal to or below 20 dBHL and normal amplitudes of transient evoked otoacoustic emissions. No association was found between the absolute latencies of waves I, III, and V, the interpeak latencies I---III, III---V, and I---V, and the cumulative lead values.ConclusionNo evidence of toxic effects from chronic low lead exposures was observed on the auditory function of children living in a lead contaminated area.CC999999/Intramural CDC HHS/United States2016-01-01T00:00:00Z25458254PMC455778

Fluctuations, correlations and non-extensivity

The present status of investigations on fluctuations and correlations seen in high energy multiparticle production processes made using the notion of nonextensivity is reviewed.Comment: Minireview presented at XXXVI International Symposium on Multiparticle Dynamica, September 2-8, 2006, Paraty (RJ), Brazil; to be published in Braz. J. Phys. (2007). Some misprints correcte

A Representation of the Virasoro Algebra via Wigner-Heisenberg Algebraic Technique to Bosonic Systems

Using the Wigner-Heisenberg algebra for bosonic systems in connection with oscillators we find a new representation for the Virasoro algebra.Comment: Revised version. Revtex, 7 pages, no figures. This work was presented in the XXII Brazilian National Meeting on Particles and Fields (October/2001), to appear in Braz. J. of Phys., 33, 1 (2003

Femtoscopic correlations in multiparticle production and beta-decay

The basics of formalism of femtoscopic and spectroscopic correlations are given, the orthogonal character of these correlations is stressed. The similarity and difference of femtoscopic correlations in multiparticle production and beta-decay is discussed.Comment: 8 pages, 3 figures, Workshop on Particle correlations and Femtoscopy (WPCF 2006), Sao Paulo, Brazil, September 9-11, 2006; to be published in Braz. J. Phy

Statistical-thermodynamical foundations of anomalous diffusion

It is shown that Tsallis' generalized statistics provides a natural frame for the statistical-thermodynamical description of anomalous diffusion. Within this generalized theory, a maximum-entropy formalism makes it possible to derive a mathematical formulation for the mechanisms that underly Levy-like superdiffusion, and for solving the nonlinear Fokker-Planck equation.Comment: 13 pages, 8 figures; to appear in special issue of Braz. J. Phys. as invited revie

Energy-Momentum Problem of Bell-Szekeres Metric in General Relativity and Teleparallel Gravity

This paper is devoted to the investigation of the energy-momentum problem in two theories, i.e., General Relativity and teleparallel gravity. We use Einstein, Landau-Lifshitz, Bergmann-Thomson and M\"{o}ller's prescriptions to evaluate energy-momentum distribution of Bell-Szekeres metric in both the theories. It is shown that these prescriptions give the same energy-momentum density components in both General Relativity and teleparallel theory. M\"{o}ller's prescription yields constant energy in both the theories.Comment: 21 pages, accepted for publication in Braz. J. Phy