La conservation apprise par observation: Variations sur quelques paramètres de la démonstration du modèle.

Studied the effectiveness of imitation and comprehension processes in learning conservation by observation: specifically, the extent to which some of the verbal and social characteristics of a model's correct demonstration of conservation problems regulate the learning of the principle involved. Three experiments were conducted with 3 groups of Canadian kindergarten and 1st-grade schoolchildren, balanced by age and sex. The same male model participated in all 3 experiments; 2 female models were added in Exp III. Classical liquid conservation and/or quantification problems were solved by the model(s) in the Ss' presence. Results show that acquisition occurred by a series of cognitive processes in which the role of social pressure to conform to the model's behavior was one of the parameters evaluated. (English abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Chloration anodique de liaisons insaturees en solvants nucleophiles - comportement des derives ethyleniques et acetyleniques

The anodic behaviour of ethylenic and acetylenic compounds is studied in the presence of chloride ion in polar solvents such as dmf and acetonitrile. The chlorination mechanism is discussed from voltammetric curves obtained with platinum or glassy carbon microelectrodes. The macroscale electrolyses allow the isolation of the mixed addition compounds, (eg) the chloroacetamides in acetonitrile and the chloroformates in dmf. When the anodic chlorinations of α aromatic acetylenic derivatives are carried in dmf, the electrolyses lead to chloroenol formates (2 F .mole^?1) and to dichloroketones (4 F .mole^?1) after the decomposition during the work up to unstable chloroimminium salts which are the primary intermediates of the reaction.     

Leek odor analysis by gas chromatography and identification of the most active substance for the leek moth,Acrolepiopsis assectella

When crushed, the leek,Allium porrum emits propyl propanethiosulfinate. The unstable thiosulfinate decomposes during GC analysis in numerous compounds, except on very short columns. The propyl propanethiosulfmate is the most attractive substance for the leek moth,Acrolepiopsis assectella. This thiosulfinate is not active onPlutella xylostella orPlodia interpunctella and seems to be repulsive onEphestia kuehniella.     

Skin optics

Quantitative dosimetry in the treatment of skin disorders with (laser) light requires information on propagation of light in the skin related to the optical properties of the individual skin layers. This involves the solution of the integro-differential equation of radiative transfer in a model representing skin geometry, as well as experimental methods to determine the optical properties of each skin layer. These activities are unified under the name skin optics. This paper first reviews the current status of tissue optics, distinguishing between the cases of: dominant absorption, dominant scattering, and scattering about equal to absorption. Then, previously published data as well as some current unpublished data on (human) stratum corneum, epidermis and dermis, have been collected and/or (re)analyzed in terms of absorption coefficient, scattering coefficient, and anisotropy factor of scattering. The results are that the individual skin layers show strongly forward scattering (anisotropy factors between 0.7 and 0.9). The absorption and scattering data show that for all wavelengths considered scattering is much more important than absorption. Under such circumstances, solutions to the transport equation for a multilayer skin model and finite beam laser irradiation are currently not yet available. Hence, any quantitative dosimetry for skin treated with (laser) light is currently lacking.     

High index microlenses for GaAlAs laser-fibre coupling

The best compromise between coupling efficiency, accuracy of positioning and reproducibility has been obtained for a high index hemispherical lens melted on the tip of an intermediate fibre between the GaAlAs laser and the transmission fibre. The letter describes the lens fabrication technique and gives various experimental results of coupling efficiencies and mechanical tolerances.     

Confrontation Vurpillot-Gibson: Recension du Livre de Monde Visuel du Jeune Enfant par Elaine Vurpillot.

Reviews the book, The Visual World of the Child by Elaine Vurpillot (1972). By reading this work in which Vurpillot approaches, by the genetic method, the problem of the perceptive conduits of identification and differentiation, it is difficult to envision a confrontation between this new approach and that of Eleanor Gibson (1969). It is done from a point of view of comparison which the work of Vurpillot will be analyzed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)