Degradation and disappearance of ortho, para isomer of technical DDT in living and dead avian tissues

The O,p'-DDT in technical DDT is broken down to p,p'-DDT and then to 1,1-dichloro- 2,2-bis(p-chlorophenyl)ethylene in living avian tissue. In the anaerobic conditions existing after death, O,p'-DDT is metabolized to 1,1-dichloro-2-(O-chlorophenyl)-2-(p-chlorophenyl)ethane. The absence of O,p'-DDT and metabolites in field specimens is ascribed to the rapid rate of breakdown and a masking of the 1,1-dichloro-2-(O-chlorophenyl)-2-(p-chlorophenyl)ethane residue during analysis by the relatively large amounts of 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene.     

Rat brain: effects of environmental enrichment on wet and dry weights

Wet weight of rat cerebral cortex was increased by exposure to an enriched environment, as compared with standard colony or impoverished conditions. Dry weights and wet weights were compared and both yielded identical percentage differences between brains of animals experiencing enrichment and those experiencing impoverishment.     

Habituation of electrically induced readiness to gnaw

Electrical stimulation of the hypothalamus in prairie dogs (Cynomys ludovicianus) produced a readiness to gnaw which decreased over time, exhibited spontaneous recovery, and could be dishabituated by foot shock. The response decrement was in part habituatory and could modify the interaction between a stimulation-induced readiness to gnaw and a physiologically induced hunger. Functional plasticity of stimulation-induced behavior might be accounted for, in part, by habituation.     

Crustal plates in the central atlantic

Various people have proposed that North and South America are a part of a gigantic crustal plate within which little differential movement is taking place. Considerations of the size of this postulated plate and the pattern of seismicity around the Caribbean indicate that it is in fact two plates, separated in the region between the Lesser Antilles and the Mid-Atlantic Ridge. Many of the offsets of the Mid-Atlantic Ridge opposite the Caribbean are the result of differential spreading rates and the westward continuations of the fracture zones extending from these offsets are active left-lateral faults.