Early Holocene crop cultivation and landscape modification in Amazonia.

The onset of plant cultivation is one of the most important cultural transitions in human history1-4. Southwestern Amazonia has previously been proposed as an early centre of plant domestication, on the basis of molecular markers that show genetic similarities between domesticated plants and wild relatives4-6. However, the nature of the early human occupation of southwestern Amazonia, and the history of plant cultivation in this region, are poorly understood. Here we document the cultivation of squash (Cucurbita sp.) at about 10,250 calibrated years before present (cal. yr BP), manioc (Manihot sp.) at about 10,350 cal. yr BP and maize (Zea mays) at about 6,850 cal. yr BP, in the Llanos de Moxos (Bolivia). We show that, starting at around 10,850 cal. yr BP, inhabitants of this region began to create a landscape that ultimately comprised approximately 4,700 artificial forest islands within a treeless, seasonally flooded savannah. Our results confirm that the Llanos de Moxos is a hotspot for early plant cultivation and demonstrate that-ever since their arrival in Amazonia-humans have markedly altered the landscape, with lasting repercussions for habitat heterogeneity and species conservation.

Dieta e câncer gástrico: aspectos históricos associados ao padrão de consumo alimentar no estado do Pará / Diet and gastric cancer: historical aspects associated with dietary patterns in the state of Pará, Brazil

O câncer gástrico ainda constitui importante problema de saúde pública no estado do Pará, onde as taxas de mortalidade apresentam valores acima da média brasileira. As bases históricas de ocupação de espaço na Amazônia, bem como as relações econômico-sociais estabelecidas ao longo desse processo, marcaram o padrão alimentar desse Estado. Este trabalho tem por objetivo reconstruir as principais características do padrão alimentar dessa população no século passado. Procurou-se identificar todas as publicações científicas disponíveis que relacionavam dados sobre os hábitos alimentares dos residentes do Pará no século XX. A partir dessas publicações, foi possível caracterizar o padrão alimentar da população paraense no século XX, que incluía um elevado consumo de sal, utilizado na conservação de carnes e frutos do mar, um consumo relativamente reduzido e irregular de legumes e verduras e uma importante ingestão de glicídios, a partir da farinha de mandioca, muitas vezes adicionada de corantes artificiais. O padrão de dieta retratado, provavelmente comum a outras regiões da Amazônia, pode ser caracterizado, com base na literatura científica, como potencialmente favorecedor de certas condições associadas à carcinogênese gástrica. Nesse sentido, ele poderia ter contribuído, em parte, para a alta mortalidade por essa neoplasia registrada na região Norte.

Gastric cancer still constitutes an important public health problem in the state of Pará, Brazil, where mortality rates are above the Brazilian average rates. The historical basis of occupation of the Amazon region, as well as the social-economic relations established during this process, have marked the dietary patterns of this state. The aim of this work is to reconstruct some of the main characteristics of the dietary pattern of the population of Pará in the last century. We sought to identify all the scientific papers that contained data on the dietary habits of the population of Pará during the XX Century. This material allowed us to characterize the eating pattern of this population during the XX Century which included an elevated consumption of salt, used to preserve meats and seafood, a relatively low and irregular consumption of legumes and leaves and an important consumption of carbohydrates with the cassava flour being the main source and frequently containing dyestuffs. This dietary pattern, probably common to other regions of the Amazon, can be characterized as potentially supportive of certain conditions associated with gastric carcinogenesis. In this sense it could have contributed, at least partially, to the high mortality rates from this neoplasia in the Amazon region of Brazil.