Gravity influences the position of the dorsoventral axis in medaka fish embryos (Oryzias latipes).

To determine whether gravity influences the plane of bilateral symmetry in medaka embryos, zygotes were placed with their animal-vegetal axis orientated vertically and with their vegetal pole elevated. Then, at regular intervals during the first cell cycle, the zygotes were tilted 90 degrees for about 10 min and subsequently returned to their original orientation. In embryos tilted during the first half of the first cell cycle, the embryonic shield formed on the side that had been lowermost when the zygote was tilted. In embryos that were tilted twice, first in one direction and then in the opposite direction, the embryonic shield formed on the side that was lowermost the first time. When zygotes were centrifuged at 5 g, the embryonic shield formed on the outwardly radial (centrifugal) side of the embryo. The orientation of the array of parallel microtubules in the vegetal pole region was also influenced by tilting or centrifuging zygotes. No correlation was found between the positions of the polar body and the micropyle and the plane of bilateral symmetry. It was concluded that gravity influences both the plane of bilateral symmetry and the orientation of microtubules in the vegetal pole region of medaka embryos.

Coping and defense in relation to accommodation among a sample of blind men.

The relation of 26 measures of ego functioning, as assessed by the responses of 101 blind men to the California Psychological Inventory, to employment status and travel freedom were examined. Previous research findings and methodology and the need to control for intervening variables were discussed. The accommodation of blindness was characterized by greater cognitive and intellectual articulation, the absence of intraceptive rigidity, and the flexible regulation of affect and impulse. While this pattern held true for those subjects born partially sighted and those acquiring total and partial blindness, no differences emerged for subject born totally or partially blind. Support was found for the construct validity of the ego measures, as well as Haan's proposition of complementary pairing of ego functions. On the basis of these results specific recommendations were made regarding the administration of the scales and counseling among the blind.