Floristic and phytosociology in dense “terra firme” rainforest in the Belo Monte Hydroelectric Plant influence area, Pará, Brazil

The objective of the present study was to characterise the floristic and phytosociological composition on a stretch of dense “Terra Firme” rainforest located in the Belo Monte hydroelectric plant area of influence, located in the state of Pará, Brazil. All trees with DAP > 10 cm situated in 75 permanent plots of 1 ha were inventoried. 27,126 individuals trees (361 ind.ha-1), distributed in 59 botanical families, comprising 481 species were observed. The families with the largest number of species were Fabaceae (94), Araceae (65) and Arecaceae (43), comprising 43.7% of total species. The species Alexa grandiflora (4.41), Cenostigma tocantinum (2.50) and Bertholletia excelsa (2.28) showed the highest importance values (IV). The ten species with greater IV are concentrated (22%). The forest community has high species richness and can be classified as diverse age trees, heterogeneous and of medium conservation condition. © 2015, Instituto Internacional de Ecologia. All rights reserved

Human and Rodent Homologies in Action Control: Corticostriatal Determinants of Goal-Directed and Habitual Action

Recent behavioral studies in both humans and rodents have found evidence that performance in decision-making tasks depends on two different learning processes; one encoding the relationship between actions and their consequences and a second involving the formation of stimulus–response associations. These learning processes are thought to govern goal-directed and habitual actions, respectively, and have been found to depend on homologous corticostriatal networks in these species. Thus, recent research using comparable behavioral tasks in both humans and rats has implicated homologous regions of cortex (medial prefrontal cortex/medial orbital cortex in humans and prelimbic cortex in rats) and of dorsal striatum (anterior caudate in humans and dorsomedial striatum in rats) in goal-directed action and in the control of habitual actions (posterior lateral putamen in humans and dorsolateral striatum in rats). These learning processes have been argued to be antagonistic or competing because their control over performance appears to be all or none. Nevertheless, evidence has started to accumulate suggesting that they may at times compete and at others cooperate in the selection and subsequent evaluation of actions necessary for normal choice performance. It appears likely that cooperation or competition between these sources of action control depends not only on local interactions in dorsal striatum but also on the cortico-basal ganglia network within which the striatum is embedded and that mediates the integration of learning with basic motivational and emotional processes. The neural basis of the integration of learning and motivation in choice and decision-making is still controversial and we review some recent hypotheses relating to this issue