Karger AG, Basel”
“The main goal of the study was to investigate whether the presence of affordances, such as physical properties of given objects and resulting movement constraints, induce a performance increase in actual tool-use compared to demonstrating it with only the tool or pantomiming it without the tool and recipient object. In the present study the perception of affordances was manipulated Semaxanib in vivo by omission or supply of contextual information.
The three execution modes – pantomiming, demonstration and actual use, – were investigated concerning the actions hammering and scooping in 25 patients with left unilateral brain damage and 10 healthy controls. The content of the movement, the grip formation, the direction and the location of the movement were evaluated with video-analysis. The results show that the pantomime condition
is most prone to errors. The information given by the tool and the recipient object in the actual use task seems to facilitate especially scooping – the more complex tool-use action. A factor analysis and the high correlation between performance-scores show that the three execution modes of both actions have a major common factor. One possible joint commonality of the execution modes could be the nature of an action related working memory component, which is responsible for the recall and the integration of semantic information into a movement-plan. Additional analyses with a smaller group revealed a second factor, that might depict the online processing of spatial relationships of the IWR-1 cost hand, the tool and the recipient objects.
The results indicate that performance improvement can be achieved by providing perceptual cues and reducing the degrees of freedom for the required action. It is concluded that manipulating affordances in a tool use context should be taken into consideration for future investigation of therapeutic approaches. (C) 2011 Elsevier Ltd. All rights reserved.”
“Our goal was to characterize changes in flow and diameter with vascular endothelial cell growth factor A (VEGF-A) and fibroblast growth factor 2 (FGF2). Observations were made JPH203 chemical structure in arteriolar networks of the cheek pouch tissue in anesthetized hamsters (pentobarbital
70 mg/kg, i.p., n = 45). Local and remote dilation responses to micropipette-applied VEGF or FGF2 yielded similar EC(50) values. The role of gap junctions in the remote response was tested by applying sucrose, halothane or 18 alpha GA to the feed arteriole midway between the remote stimulation and upstream observation sites; all remote dilation to FGF2 was prevented, while only the early dilation to VEGF was blocked. The remote dilation to VEGF displayed a second rheologic mechanism. The second mechanism involved an abrupt increase in upstream velocity and shear rate, followed by nitro-arginine sensitive dilation. To test whether the abrupt increase in shear could be caused by other agents known to cause edema, remote responses to histamine and thrombin were tested.