The Development of the Vestibular Apparatus Under Conditions of Weightlessness

A series of experiments has been carried out on the effect of space flight conditions on morphogenesis and the structure of the vestibular apparatus in amphibian and fish larvae. Larval development proceeded in weightlessness without serious morphological defects. The vestibular apparatus developed; its organization in the experimental animals did not differ qualitatively from that in the controls. The specific external stimulus (gravitation) appears not to be a necessary condition for the development of a gravitation receptor in ontogenesis although the appearance of the vestibular apparatus in phylogenesis was apparently related to this stimulus

Elastic domains in antiferromagnets

We consider periodic domain structures which appear due to the magnetoelastic interaction if the antiferromagnetic crystal is attached to an elastic substrate. The peculiar behavior of such structures in an external magnetic field is discussed. In particular, we find the magnetic field dependence of the equilibrium period and the concentrations of different domains

The effect of O2 impurities on the low temperature radial thermal expansion of bundles of closed single-walled carbon nanotubes

The effect of oxygen impurities upon the radial thermal expansion (ar) of bundles of closed single-walled carbon nanotubes has been investigated in the temperature interval 2.2-48 K by the dilatometric method. Saturation of bundles of nanotubes with oxygen caused an increase in the positive ar-values in the whole interval of temperatures used. Also, several peaks appeared in the temperature dependence ar(T) above 20 K. The low temperature desorption of oxygen from powders consisting of bundles of single-walled nanotubes with open and closed ends has been investigatedComment: 7 pages, 3 figure