Bibliometric parameters have been used in order to evaluate a scientist's performance. The h-index has been gradually accepted as the most adequate parameter for this purpose. To have an idea of this index among Brazilian scientists, we performed an analysis of this parameter for the full members of the Brazilian Academy of Sciences (BAS). The h-index of 402 members listed in 10 distinct categories by the BAS was determined, cross-checked with the curriculum vitae of each of them listed at the Plataforma Lattes database (CVL) and compared with each other. Despite the large production, mostly in journals without impact factor, the h-indexes among the BAS members are comparatively low and show a large variation in all of the 10 categories, particularly in Biomedical and Physical sciences. The highest average of h-index values was found in Biomedical, Health and Chemical sciences; the lowest values were found in Human sciences where this index is meaningless. Several problems due to the trend that new and "fresh" publications need be constantly produced (the "bakery-effect") are discussed. This study points to the need of developing countries such as Brazil to invest in national scientific journals in order to make them gradually part of the mainstream journals. This would have a positive effect on bibliometric parameters of Brazilian researchers, including the h-index.

The depositional model of the Cabeças Formation is re-evaluated in the context of the Devonian paleogeography of the Parnaíba Basin, and with particular reference to similarities between the formation's facies associations on the eastern border of the basin and the flood-dominated fluvio-deltaic system facies that have been discussed in recent literature. The widespread occurrence and nature of sigmoidal clinoforms (with asymptotic cross-stratification and climbing ripples) of the Cabeças Formation are here considered as strong evidence of flood-influenced depositional settings. Sandy strata of the Passagem Member, in the vicinity of Pimenteiras and Picos (Piauí State), are interpreted as the distal part of fine-grained mouth-bar deposits interbedded with delta-front sandstone lobes showing hummocky cross-stratification. Richly fossiliferous levels, with diverse megainvertebrates and plant cuticles, occur within the delta-front lobes and the distal mouth-bar deposits, reflecting continuation of shallow marine conditions.