Utilisation de la centrifugation analytique pour la mesure, au sein d'un extrait brut d'E. coli , du coefficient de sédimentation du complexe de décarboxylation oxidative du pyruvate

We have applied successfully the active enzyme analytical centrifugation method (A.E.C.) to the study of the well known pyruvate dehydrogenase complex (P.D.C.) in crude extracts from E. coli. It is not possible to study the complex in a spectrophotometer (through its dehydrogenase activity) due to NADH oxidase activities. The A.E.C. method, which overcomes this difficulty, can also be viewed as a refined spectrophotometric method.

Modifying the Ionosphere with Intense Radio Waves

The ionospheric modification experiments provide an opportunity to better understand the aeronomy of the natural ionosphere and also afford the control of a naturally occurring plasma, which will make possible further progress in plasma physics. The ionospheric modification by powerful radio waves is analogous to studies of laser and microwave heating of laboratory plasmas (20). " Anomalous" reflectivity effects similar to the observed ionospheric attenuation have already been noted in plasmas modulated by microwaves, and anomalous heating may have been observed in plasmas irradiated by lasers. Contacts have now been established between the workers in these diverse areas, which span a wide range of the electromagnetic spectrum. Perhaps ionospheric modification will also be a valuable technique in radio communications.

Differential cerebral processing of noise and verbal stimuli

Psychophysiological measurements have indicated that the right cerebral hemisphere processes noises and other nonverbal data and that the left cerebral hemisphere processes verbal material. Direct physiological measurements, as expressed in summated auditory evoked cortical responses, unequivocally demonstrate that click noises show a greater amplitude of initial output over the right brain, and that verbal stimuli produce either equal or higher amplitudes of output over the left cerebral hemisphere.

An Analytical Study of the Dynamics of an Elastic Linkage

The transverse vibrational characteristics of the connecting rod in a slider-crank mechanism are investigated. The equations of motion are derived, simplified, and solved. For the solution, two different numerical techniques are employed and correlation is achieved. Two dimensionless parameters, S the speed parameter and Z the physical parameter, arise during the derivation of the equations of motion. These parameters can be used by the designer as an indication of the vibrational activity of the mechanism.