0000000000019552
AUTHOR
Micheline Boquillon
Les représentations spatiales de concepts scientifiques : inventaire et diversité
The consultation of twelve journals (French and English language) that deal with science education, for the years 1991 to 1993, allowed us to summarize the use of spatial representations of scientific concepts in didactics research. Two main results were produced from this study : there has not been much work published with spatial representations, and what has been published is very heterogeneous. Analysis of this diversity does not always allow us to understand the authors’ objectives and obliges researchers in didactics to think about the nature and role of spatial representations in the construction of scientific knowledge.
Effect of acidosis on lipid peroxidation in brain slices.
Acidification of the incubation medium markedly increased lipid peroxidation of cortical brain slices. Lactic acidosis caused a more extensive lipid peroxidation than did phosphoric acidosis (+35% at pH 6 and +81% at pH 5), probably due to the rapid diffusion of the protonated form of lactic acid across cell membranes. These results support the hypothesis that free radical mechanisms may be involved in the cytotoxicity of acidosis.