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.     

Tongue cooling: a new reward for thirsty rodents

Thirsty rodents will persistently lick a stream of dry air pumped through a standard drinking tube. This air-licking is attenuated by experimental manipulations which reduce the evaporative cooling of the tongue and mouth produced by the airstream. This suggests that such cooling is itself an effective reward for thirstry rodents. We tested this hypothesis by presenting thirsty rodents with a piece of cold, dry metal. Different species spent from 9 to 40 percent of their session time licking the cold metal. When deprived of water hamsters reared from birth without access to drinking water licked cold metal in preference to metal maintained at room or body temperature. This preference was approximately equal to that of littermates reared normally. We conclude that tongue cooling is a primary reward for thirsty rodents.     

Neutron scattering: progress and prospects

Over the last decade the unique properties of neutrons have proven useful in a growing number of scientific disciplines. Neutron scattering, traditionally the probe of choice for many magnetic and spectroscopic studies, is now firmly established as an invaluable complement to x-ray scattering for structural and dynamic studies within many other areas of the material sciences, chemistry, and biology. In recent years the instruments and techniques have matured to the point where they are of increasing relevance to the understanding and design of improved practical, everyday materials.