A toxic dipeptide from the defense glands of the colorado beetle

The Colorado beetle is protected against predators by the secretions of defensive glands located on the pronotum and the elytra. The single major compound of the secretion was identified as gamma-L-glutamyl-L-2-amino-3(Z),5-hexadienoic acid by spectroscopic and chemical methods. This compound, which contains a nonprotein beta,gamma- unsaturated amino acid, is toxic to ants (Myrmica rubra) at a concentration 10(-2) molar, which is less than its estimated concentration in the secretion (1.8 x 10(-1) molar).     

Age of the earliest african anthropoids

The earliest fossil record of African anthropoid primates (monkeys and apes) comes from the Jebel Qatrani Formation in the Fayum depression of Egypt. Reevaluation of both geologic and faunal evidence indicates that this formation was deposited in the early part of the Oligocene Epoch, more than 31 million years ago, earlier than previous estimates. The great antiquity of the fossil higher primates from Egypt accords well with their primitive morphology compared with later Old World higher primates. Thus, the anthropoid primates and hystricomorph rodents from Fayum are also considerably older than the earliest higher primates and rodents from South America.     

Changing climate: geothermal evidence from permafrost in the alaskan arctic

Temperature profiles measured in permafrost in northernmost Alaska usually have anomalous curvature in the upper 100 meters or so. When analyzed by heat-conduction theory, the profiles indicate a variable but widespread secular warming of the permafrost surface, generally in the range of 2 to 4 Celsius degrees during the last few decades to a century. Although details of the climatic change cannot be resolved with existing data, there is little doubt of its general magnitude and timing; alternative explanations are limited by the fact that heat transfer in cold permafrost is exclusively by conduction. Since models of greenhouse warming predict climatic change will be greatest in the Arctic and might already be in progress, it is prudent to attempt to understand the rapidly changing thermal regime in this region.