Electron spin resonance absorption of tissue constituents.

The electron spin resonance spectra at g = 2 of the structural and soluble proteins of mouse liver have been investigated separately. The structural materials have signals an order of magnitude stronger. Radicals with important similarities to those occurring in natural tissue can be induced by treating casein with methylglyoxal or crotonaldehyde.

Latitudinal and population specific differences in timing of daily and seasonal functions in redpolls (Acanthis flammea).

1. The daily (circadian) rhythm of activity and rest of common redpolls (Acanthis f. flammea L.

Re-entrainment of circadian rhythms after phase-shifts of the Zeitgeber.

To describe anabrupt shift of the Zeitgeber sufficiently, it is necessary to indicate whether the phase has been advanced or delayed, for how many hours it has been shifted, and what part of the Zeitgeber has been lengthened or shortened respectively. The entrained circadian system usually follows a shift of the Zeitgeber in the same direction and by an equal amount. However, there can be exceptions to both of these rules: a) an instantaneous 12-h shift of a (symmertric) Zeitgeber always represents a delya (= doubling of one-half of its period).

Dielectrophoresis of cells.

Dielectrophoresis, the motion produced by the action of nonuniform electric field upon a neutral object, is shown to be a simple and useful technique for the study of cellular organisms. In the present study of yeast (Saccharomyces cerevisiae) using a simple pin-pin electrode system of platinum and high-frequency alternating fields, one observes that the collectability of cells at the electrode tip, i.e.