The effect of context on semantic differential ratings.

Presents 3 studies testing the effect of context on semantic differential ratings. 1 view (absolutistic) considers each rating an independent judgment, which should not be affected by context. From a relativistic viewpoint, context establishes a frame of reference which should affect the ratings. This latter view would predict a decrease in the variability in rating concepts as the context shifts from homogeneous to heterogeneous to contrast conditions. Results of all 3 studies support the absolutistic position. (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Desferrioxamine-promoted virulence of Yersinia enterocolitica in mice depends on both desferrioxamine type and mouse strain

The effects of desferrioxamine B (DFOB) and G (DFOG) on growth promotion and virulence of Yersinia enterocolitica as well as on T cell activation and proliferation were investigated. Both desferrioxamines promoted growth of Y. enterocolitica O:8 (WA-314) and O:3 (Y-108). DFOB had a greater immunosuppressive effect on T cells than did DFOG. These results suggest a dual role of DFOB in yersiniosis: growth promotion of the pathogen and immunosuppression of the host. The LD50 of both Yersinia strains for mice was reduced by DFOB but not by DFOG. However, the LD50 of yersiniae was reduced by DFOB to a greater extent in Yersinia-resistant C57BL/6 than in Yersinia-susceptible BALB/c mice. The different impact of DFOB on the LD50 of Y. enterocolitica in C57BL/6 and BALB/c mice might be due to an immunomodulating effect of DFOB.     

Water Vapor and Oxygen Degradation Mechanisms in Organic Light Emitting Diodes

The degradation of organic light emitting diodes (OLEDs) due to the growth of dark spots can be attributed to the synergy of three external causes: dust particles deposited during the fabrication process, pollution by water vapor, and pollution by oxygen. On the basis of a set of new experiments performed on benchmark devices, we demonstrate that, for a given distribution of dust particles and a given concentration of the polluting agent, water is a thousand times more destructive than oxygen at room temperature. While the thermal diffusion of oxygen causes the oxidation of both the metal at the interface and the dye in the bulk of the device, water acts by an electrochemical process causing the delamination of the electrode.