Noise and "pedagogic efficiency" in school activities.

A group of 8 pupils born in 1962 and a group of 8 future teachers between 25 and 40 years of age, were submitted in 1975 to two types of tests in the presence of environment noises at various levels (45 to 75 dBa), in order to assess the influence of this nuisance on the pedagogic efficiency. The results show a nocivity threshold for the pupils at around 55 dBA and for the teachers at aroung 65 dBA. Furthermore, backward pupils suffer more in this context from the interference of noise than the advanced ones.     

Intracellular recording of secretory potentials in a "mixed" salivary gland.

Secretory potentials evoked by nerve stimulation have been recorded from both types of cell (peripheral and central) present in the acini of cockroach salivary glands.     

Concentration of "available" unesterified cholesterol in human plasma as evaluated from inhibition of hemolysis by lucensomycin.

The unesterified cholesterol content of plasma samples can be evaluated from the extent of inhibition of lucensomycin-induced hemolysis. The test measures, however, only the fraction of cholesterol which is available for interaction with lucensomycin, this availability being adversely affected by high phospholipid-cholesterol ratios.