Periodontal outcomes and social, racial and gender inequalities in Brazil: a systematic review of the literature between 1999 and 2008 Condições periodontais e desigualdades sociais, raciais e de gênero no Brasil: revisão sistemática da literatura do período de 1999 a 2008

The objective of this study was to review the Brazilian epidemiologic literature on periodontal outcomes and socio-demographic factors, assessing bibliographic and methodological characteristics of this scientific production, as well as the consistency and statistical significance of the examined associations. A systematic review was carried out in six bibliographic sources. The review was limited to the period between 1999 and 2008, without any other type of restriction. Among the 410 papers identified, 29 were included in the review. An increasing number of articles, specifically in the last four years of study, was observed. However, there is a concentration of studies in the South and Southeast regions of Brazil, and many of them are not closely connected to theoretical formulations in the field. In spite of these shortcomings, the review findings corroborate the idea that poor socioeconomic conditions are associated with periodontal outcomes, as demonstrated primarily by income and schooling indicators.<br>O objetivo deste trabalho foi revisar a literatura epidemiológica brasileira sobre condições periodontais e aspectos sociodemográficos, avaliando características bibliográficas e metodológicas dessa produção, bem como a consistência e a significância estatística das associações examinadas. Foi conduzida uma revisão sistemática, por meio de consulta eletrônica, a seis fontes bibliográficas. A revisão foi restrita ao período de 1999 a 2008, sem a imposição de quaisquer outros limites de pesquisa. Entre os 410 artigos identificados, 29 foram incluídos na revisão. Observa-se crescimento da produção, especialmente no último quadriênio. Entretanto, há uma concentração dos estudos nas regiões Sul e Sudeste do país, e os trabalhos não se apoiam explicitamente em elaborações teóricas pertinentes ao tema. Apesar dessas limitações, os resultados dessa revisão sugerem que há uma relação inversa entre indicadores socioeconômicos e desfechos periodontais, demonstrada especialmente por indicadores de renda e escolaridade

A Modern View on the Red Sea Rift: Tectonics, Volcanism and Salt Blankets

Continental rifting and ocean basin formation can be observed at the present day in the Red Sea, which is used as the modern analogue for the formation of mid-ocean ridges. Competing theories for how spreading begins—either by quasi-instantaneous formation of a whole spreading segment or by initiation of spreading at multiple discrete “nodes” separated by thinned continental lithosphere—have been put forward based, until recently, on the observations that many seafloor features and geophysical anomalies (gravity, magnetics) along the axis of the Red Sea appeared anomalous compared to ancient and modern examples of ocean basins in other parts of the world. The latest research shows, however, that most of the differences between the Red Sea Rift (RSR) and other (ultra)slow-spreading mid-ocean ridges can be related to its relatively young age and the presence and movement of giant submarine salt flows that blanket large portions of the rift valley. In addition, the geophysical data that was previously used to support the presence of continental crust between the axial basins with outcropping oceanic crust (formerly named “spreading nodes”) can be equally well explained by processes related to the sedimentary blanketing and hydrothermal alteration. The observed spreading nodes are not separated from one another by tectonic boundaries but rather represent “windows” onto a continuous spreading axis which is locally inundated and masked by massive slumping of sediments or evaporites from the rift flanks. Volcanic and tectonic morphologies are comparable to those observed along slow and ultra-slow spreading ridges elsewhere and regional systematics of volcanic occurrences are related to variations in volcanic activity and mantle heat flow. Melt-salt interaction due to salt flows, that locally cover the active spreading segments, and the absence of large detachment faults as a result of the nearby Afar plume are unique features of the RSR. The differences and anomalies seen in the Red Sea still may be applicable to all young oceanic rifts, associated with plumes and/or evaporites, which makes the Red Sea a unique but highly relevant type example for the initiation of slow rifting and seafloor spreading and one of the most interesting targets for future ocean research