Este artigo prolonga a análise do argumento apresentado por Descartes em favor da primeira certeza no início da Segunda Meditação, iniciada em um artigo anterior. É examinada a passagem subsequente ao referido argumento com vistas a estabelecer que sua compreensão aponta para um debate velado entre Descartes e seus leitores versa- dos na doutrina escolástica, mais particularmente nas concepções da definição como estruturada pela composição do gênero e da diferença e de específica e de conceito universal abstrato. Procuro mostrar que as razões que Des- cartes dispõe para recusar essas concepções podem ser extraídas de certa interpretação do argumento em favor da certeza da proposição eu existo e que essa recusa é imprescindível para a compreensão adequada do penso, logo existo e, portanto, de seu argumento em favor do dualismo.

Este artigo prolonga a análise do argumento apresentado por Descartes em favor da primeira certeza no início da Segunda Meditação, iniciada em um artigo anterior. É examinada a passagem subsequente ao referido argumento com vistas a estabelecer que sua compreensão aponta para um debate velado entre Descartes e seus leitores versa- dos na doutrina escolástica, mais particularmente nas concepções da definição como estruturada pela composição do gênero e da diferença e de específica e de conceito universal abstrato. Procuro mostrar que as razões que Des- cartes dispõe para recusar essas concepções podem ser extraídas de certa interpretação do argumento em favor da certeza da proposição eu existo e que essa recusa é imprescindível para a compreensão adequada do penso, logo existo e, portanto, de seu argumento em favor do dualismo.

Judgments about the validity of at least some elementary inferential patterns (say modus ponens) are a priori if anything is. Yet a number of empirical conditions must in each case be satisfied in order for a particular inference to instantiate this or that inferential pattern. We may on occasion be entitled to presuppose that such conditions are satisfied (and the entitlement may even be a priori), yet only experience could tell us that such was indeed the case. Current discussion about a perceived incompatibility between content externalism and first-person authority exemplifies how damaging the neglect of such empirical presuppositions of correct reasoning can be. An externalistic view of mental content is ostensibly incompatible with the assumption that a rational subject should be able to avoid inconsistency no matter what the state of her empirical knowledge may be. That fact, however, needs not be taken (as it often is) as a reductio of externalism: alternatively, we may reject that assumption, adding to the agenda of a philosophical investigation of rationality an examination of the vicissitudes of logical luck. I offer an illustration and defense of that alternative.

In this work was investigated the effect of pre-treatment with (PhSe) 2 and (PhTe) 2 on chemical seizure and 4-aminopyridine-induced lethality in mice. Additionally, lipid peroxidation levels of whole brain after treatment with 4-aminopyridine and effect of pre-treatment with (PhSe) 2 and (PhTe) 2 on these levels were investigated. Mice were pre-treated with (PhSe) 2 or (PhTe) 2 (50, 100, or 150 $μ$mol/kg) 30 min before 4-aminopyridine (12 mg/kg) administration. The treatment with 4-aminopyridine caused a significant incidence of seizures (clonic, tonic) and death. Pre-treatment with (PhSe) 2 and (PhTe) 2 significantly increased the latency for clonic and tonic seizures, and prevented 4-aminopyridine-induced death. Significantly, the pre-treatment with (PhSe) 2 or (PhTe) 2 increased the latency for clonic seizures in a dose-dependent manner. Additionally, a significant increase was observed in the brain lipid peroxidation level after treatment with 4-aminopyridine, which was significantly inhibited by pre-treatment with 150 $μ$mol/kg (PhSe) 2 or (PhTe) 2 . These results demonstrate that (PhSe) 2 and (PhTe) 2 counteract the harmful effects of 4-aminopyridine. It is possible that this effect results from modulation of the redox state of N-methyl-d-aspartate receptors and/or of Ca 2+ channel activity with subsequent alteration in neurotransmitter release. Importantly, this study provides evidence for anticonvulsant and antioxidant properties of (PhSe) 2 and (PhTe) 2′ which indicates a neuroprotective activity of these compounds.

A kinetic approach to the problem of wave propagation in dusty plasmas, which takes into account the variation of the charge of the dust particles due to inelastic collisions with electrons and ions, is utilized as a starting point for the development of a new formulation, which writes the components of the dielectric tensor in terms of a finite and an infinite series, containing all effects of harmonics and Larmor radius. The formulation is quite general and valid for the whole range of frequencies above the plasma frequency of the dust particles, which were assumed motionless. The formulation is employed to the study of electrostatic waves propagating along the direction of the ambient magnetic field, in the case for which ions and electrons are described by Maxwellian distributions. The results obtained in a numerical analysis corroborate previous analysis, about the important role played by the inelastic collisions between electrons and ions and the dust particles, particularly on the imaginary part of the dispersion relation. The numerical analysis also show that additional terms in the components of the dielectric tensor, which are entirely due these inelastic collisions, play a very minor role in the case of electrostatic waves, under the conditions considered in the present analysis.

The aim of this study was to evaluate flossing as a diagnostic method for interproximal gingival bleeding in children. For this crossover study, 23 pre-schoolchildren presenting neither restorations nor approximal carious cavities and with at least 15% of gingival bleeding sites were selected. Examinations were performed at three different moments (3-4 days interval). Examinations comprised repeated measurements of two gingival indices with a 10-minute interval in the following sequences: the Ainamo & Bay Gingival Bleeding Index (GBI) followed by the Carter & Barnes flossing index (CBI); CBI followed by GBI; and GBI followed by GBI. Data analysis was performed only for the interproximal sites, considering the GBI as the gold-standard. Agreement between indices, sensitivity (SE), specificity (SP), positive (PPV) and negative predictive values (NPV) were estimated. Percentage agreements in sequences GBI-CBI, CBI-GBI and GBI-GBI were 70.3%, 76.4% and 84.5%, respectively. Validation of flossing in the first sequence (GBI-CBI) resulted in values of 0.61 (95%CI 0.53 - 0.68), 0.72 (95%CI 0.69 - 0.76), 0.33 (95%CI 0.28 - 0.39) and 0.89 (95%CI 0.86 - 0.92) respectively for SE, SP, PPV and NPV. It can be concluded that professional flossing is a useful tool in the diagnosis of interproximal gingival inflammatory status in children, especially in conditions of gingival health.