O Censo 2010 traz diversos dados que permitem uma análise mais pormenorizada da dinâmica populacional indígena, possibilitando novos debates e acumulação de conhecimento sobre esta. Assim, com base nestes dados este trabalho pretende entender as principais dinâmicas da população indígena no município de Altamira, Estado do Pará, em específico os indígenas residentes na sede municipal e, em especial, as populações Arara, Juruna, Kuruaya e Xipaya. Uma análise histórica da cidade mostra a presença crescente de diversos grupos
indígenas, que nos últimos anos passou e ainda passa por um processo de etnogênese. Para compreendermos de maneira mais ampla os processos pelos quais esta população passou e passa, incorporaremos à análise o Estudo de Impacto Ambiental (EIA) da usina hidrelétrica de Belo Monte, que nos ajuda a traçar de maneira mais precisa a situação atual desta.

The spatial distribution of demographic variables is essential in Population and Environment studies, but the data of secondary sources – e.g. the Demographic Census – are not always provided on territorial units suitable to population distribution and landscape characteristics. In this work, we aggregate the micro-data from the Population Count 2007, of the Brazilian Institute of Geography and Statistics (IBGE), in regular grids based on household coordinates. Unlike the use of mathematical models for the spatial distribution of data, this methodology is based on the real distribution of households over the territory and enables the aggregation of population data in more adequate areas for population and environment studies, without facing problems with statistical confidentiality breach. The results are closer to the ones found in the field, besides being comparable with old and new surveys conducted by IBGE.

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.