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The mechanism by which mammalian circadian clocks are entrained to light-dark cycles is unknown. The clock that drives behavioral rhythms is located in the suprachiasmatic nucleus (SCN) of the brain, [...]

The essays that follow are drawn from invited presentations of the Conference Group on the Middle East, which meets annually in conjunction with the American Political Science Association. The essays [...]

The most critical problems confronting modern Middle East are water ownership, management and use. Reducing regional political tensions is thus a prerequisite for reaching agreements and promoting cooperative efforts among states sharing mutual resources. The Jordanian-Israeli agreements on water sharing may set an important precedent for the region, inspiring confidence that cooperation rather than conflict can relieve tensions and resolve long-standing problems.

Null mutations of the Caenorhabditis elegans unc-22 gene, when associated with hindered movement and a distortion in the muscle structure, give rise to a distinct body surface twitch. Earlier sequence analysis of the unc-22 had revealed that the encoded polypeptide termed twitching is comprised of a bone protein kinase domain, several variants of both the immunoglobulin-like domain and a fibronectin type III-like domain. The present experiment provides an explanation for the weak phenotype of a transposon insertion allele after additional information on the DNA sequence was revealed.

The effects of anoxia in extracellular concentrations of potassium ((K+)O) and calcium ((Ca2+)O) were studied in the medulla of newborn rabbits using ion-selective microelectrodes to monitor changes in the ion levels. Anoxia produced an age-dependent decrease in both (K+)O and (Ca2+)O resting concentrations in the brain stem confirming the neonatal brain's high resistance to oxygen deprivation.