The structure of A segments from glycerinated skeletal muscle.

The A band of skeletal muscle consists of an array of thick myosin-containing filaments along with non-myosin proteins such as C protein and M line protein. In order to study the arrangement of the myosin and non-myosin components, A segments which are aggregations of thick filaments held together at the M line were prepared from glycerinated chicken pectoral and rabbit psoas muscles and examined by electron microscopy. Details of the preparative technique and comparison of the morphologies of A segments and I segments are provided. The A segments from chicken pectoral muscle exhibited 11 to 12 stripes in each half lateral to the bare zone. Several less distinct bands as well as subdivisions of the individual stripes were also observed. The periodicity of the major stripes in the A segments was 424 +/- 10 A. The A segments prepared from rabbit psoas muscle had a periodicity of 432 +/- 13 A, but in contrast with chicken A segments, fewer rabbit A segments showed this periodicity. We conclude that A segments can be separated from glycerinated chicken and rabbit skeletal muscles and compare our results with those of others who prepared A segments from frog and rabbit skeletal muscles in the absence of glycerol.     

Regulation of sex determination in maize

Maize develops separate male and female flowers in different locations on a single plant. Male flowers develop at the tip of the shoot in the tassel, and female flowers develop on the ears, which terminate short branches. The development of male flowers in tassels and female flowers in ears is the result of selective abortion of pistils or stamens, respectively, in developing florets. Genetic analysis has shown that stamen abortion and pistil abortion are under the control of two different genetic pathways. Local levels of the plant hormone gibberellic acid determine whether or not stamens are suppressed. Pistil abortion is under the regulation of the tassel seed genes, one of which has been shown to encode a short-chain alcohol dehydrogenase. The tassel seed genes play a role in regulating the fate of inflorescence meristems as well as pistil primordium fate.     

ALCOHOLISM: THE ROLE OF PSYCHIATRY IN MEETING THE PROBLEM

The extensive devastation resulting from excessive ingestion of alcoholic beverages is not widely recognized. Brief statistics indicate the extent of alcoholic beverage production and consumption, of the consumer outlay for products, and of losses in wages and the cost of increased illness incident to excessive drinking. Also indicated are the cost of law enforcement requirements coincident with drunkenness, and the factor of drinking in accidents and charitable care.Some of the sociologic and economic effects are recognized by agencies involved in the problem of alcoholism, but the extensive involvement of the personality of the addict and of his family and associates, the most devastating effect of all, is inestimable. Coordination of reorganized facilities is necessary to improve the situation. As the entire problem basically involves the personality, psychiatric principles need to be applied by means of studied recommendations and advice to coordinated groups making efforts to meet this extensive problem and to assist the alcoholic addict.     

Illuminating the Nubian ‘Dark Age’: A bioarchaeological analysis of dental non-metric traits during the Napatan Period

The origins of one of the most powerful sociopolitical entities of the Nile Valley, the Napatan State (850–650 BCE), are debated. Some scholars have suggested local development of this influential Nubian State, while others propose foreign involvement. This study uses a bioarchaeological approach to examine the biological affinity of these Ancient Nubians. The focal site of this research, Tombos, is one of few non-central Napatan Period sites that have been excavated and can, therefore, shed light on the broader Napatan populace. Dental non-metric trait frequencies were examined in the Tombos sample as well as in 12 comparative samples to elucidate the biological affinities of these populations.