Ensemble asteroseismology of solar-type stars with the NASA Kepler mission.

In addition to its search for extrasolar planets, the NASA Kepler mission provides exquisite data on stellar oscillations. We report the detections of oscillations in 500 solar-type stars in the Kepler field of view, an ensemble that is large enough to allow statistical studies of intrinsic stellar properties (such as mass, radius, and age) and to test theories of stellar evolution. We find that the distribution of observed masses of these stars shows intriguing differences to predictions from models of synthetic stellar populations in the Galaxy.

[Changes in caries prevalence in 7-12-year-old children from Araraquara, São Paulo, Brazil: 1989-1995]. / Mudanças na prevalência de cárie em crianças de sete a 12 anos de Araraquara, São Paulo, Brasil: 1989-1995.

The aim of this study was to compare the prevalence of caries in 7-12-year-old children from Araraquara, São Paulo, Brazil, in 1989 and 1995. Systematic random samples were drawn from the population of children enrolled in public schools. The surveys were carried out by trained examiners using the DMFT index and WHO diagnostic criteria. There was an increase in the percentage of children free of caries in the permanent dentition in all age groups (from 29 per cent in 1989 to 51 per cent in 1995). Amongst 12 year olds, the DMFT index was 3.8 in 1989 and 2.6 in 1995. Decreases were observed in the percentages of children classified in the 1-3 DMFT index category (from 40 per cent in 1989 to 31 per cent in 1995) and in the 4-6 DMFT index category (26.6 per cent in 1989 to 16.5 per cent in 1995). There was also a reduction in the percentage of children with a DMFT of 7 or more (4.4 per cent in 1989 to 1.5 in 1995). The WHO/FDI goal for the year 2000 of a mean DMFT index no more than 3 at the age of 12 years was achieved in this population, and on-going efforts should be made to reduce the percentage of children with caries in order to achieve the WHO/FDI goals for the year 2010.

[Analysis of fluoride concentration in mineral waters in the Araraquara region in Brazil]. / Análise da concentração de flúor em águas minerais na região de Araraquara, Brasil.

It has been shown that people of all ages can benefit from the topical and systemic effects of water fluoridation. However, the increase in consumption of bottled water, either to substitute for or supplement consumption of water from public sources, has implications for safe fluoride supplementation. Taking that into consideration, in 1995 we analyzed the fluoride content in 31 commercial brands of mineral water in the region of Araraquara, state of São Paulo, Brazil. Fluoride concentration as determined by our analysis was compared to the concentration of fluoride specified on each label. Only 25% of the products studied listed the fluoride concentration on their labels. In addition, among 31 mineral water brands, 26 listed the date when the chemical analysis to determine chemical composition had been performed. Of these, 20 had not been put through the annual chemical analysis determined by Brazilian law. Based on these results, if the mineral waters tested had been the only source of drinking water, fluoride supplementation would have been necessary in 69% of the samples analyzed. In the case of children up to 6 years of age who use products containing fluoride, such as topical gels, mouthwashes or toothpastes, supplementation should be recommended only if commercially bottled water is the only source of water used, not only for drinking but for cooking as well.