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On étudie par polarographie et spectrophométrie la teneur en groupements SS et SH dans la farine de pois à différentes teneurs en eau. On montre que les concentrations sont suffisantes pour etre compatibles avec la cinétique de restauration des radicaux libres proposée antérieurement.

To study the distribution of free radicals produced by ionizing radiations in bone, the influence of different parameters (Ca/P ratio, crystalline structure, influence of impurities, molecular weight) on the production and stabilization of free radicals in synthetic apatitic crystals and collagens is investigated at room temperature and - 180°K.Whole bone and fractions of different densities were irradiated in air and in vacuum. The yields of the different types of radicals have been studied. We have shown that(1) the nature of the free radicals in the organic phase depends on the density;(2) the yield in apatite-like radicals increases with the density;(3) bone presents an increase of the radiosensitivity of the collagen and of the radioresistance of the mineral phase as compared with its isolated components;(4) toluene produces radicals in unirradiated bone; the nature and the concentration of these radicals depend on the density.Annealing after irradiation in liquid nitrogen has also been studied.Possible identifications of the nature of the free radicals observed are presented.

The evocative portrayal of small groups given by the group diagramming method naturally invites the further study of subgroups, behavioral clusters, and coalitions. Previous attempts at such study have depended on the mathematical formalism of Cluster Analysis. This is a natural choice, since much of the structure of a group is sure to be defined by the pairwise interactions which form the basis of Cluster Analytic techniques. However, several shortcomings of this method are apparent: While there is a straightforward measure of distance (the fundamental input to the Cluster Analysis) in the diagram plane, the dominance dimension appears to be qualitatively different; furthermore, it is most desirable that the analysis procedure consider all interactions simultaneously. We therefore turn to the Potential Theory of physical science which has long been used to describe assemblages of pairwise interacting “particles.” A method of characterizing probable clusters within a group is then possible based on the statistical moment description of a group —analogous to the multipole expansion of physical Potential Theory. It is hypothesized that there is an an underlying Social Interaction Potential which is clarified by the contours of the coalitions which thus emerge. Speculation on this Potential leads to other fruitful areas of inquiry.

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