Inadequate Dissemination of Phase I Trials: A Retrospective Cohort Study

François Chapuis and colleagues examine a cohort of clinical trial protocols approved by French ethics committees, and show that Phase I trials are less frequently published than other types of trials

Spatial relationships between natural resources and land use dynamics in the amazonian agricultural frontier

The objective of this work was to analyze the relationship between the natural resources (soil, topography and hydrography) and the land use dynamics in an area in eastern Amazonia between 2004 and 2013. The spatial variables used were soil texture, topographic wetness index, slope and drainage distance. We used the method of weights of evidence to observe the relations between the transitions of land use and the spatial variables. In mechanized agriculture and large landholding area, the results show that the behavior of deforestation and pasture transformation responds to the soil texture and topography variables. In the smallholding areas, the relationship with natural resources is different and may be more related to the historical development of the expansion of the valleys towards the plateaux