Any gardener knows--different plant species mature at different times. Scientists studying plant communities in natural habitats call this phenomenon "complementarity." It allows many species to co-exist because it reduces overlap in the time period when species compete for limited resources. Now, in a study posted online the week of Sept. 4 in the Proceedings of the National Academy of Sciences, ecologists working at Stanford's Jasper Ridge Biological Preserve report evidence that climate change may alter this delicate balance.

Psychologists have long known that memories of disturbing emotional events - such as an act of violence or the unexpected death of a loved one - are more vivid and deeply imprinted in the brain than mundane recollections of everyday matters.

The golden age of dinosaur discovery is yet upon us, according to Peter Dodson at the University of Pennsylvania. In a forthcoming issue of the Proceedings of the National Academy of Sciences, Dodson revises his groundbreaking 1990 census on the diversity of discoverable dinosaurs upward by 50%, offering a brighter outlook about the number of dinosaurs waiting to be found. His findings also add evidence that dinosaur populations were stable, and not on the decline, in the time shortly before their extinction 65 million years ago.

Children of men age 40 and older have a significantly increased risk of having autism spectrum disorders compared with those whose fathers are younger than 30 years, according to an article in the September issue of Archives of General Psychiatry, one of the JAMA/Archives journals.

A new drug has been shown to improve blood flow in diseased arteries, reducing the risk of high blood pressure and heart attacks, a Monash University study published today reveals.

Blood cells have limited lifespans, which means that they must be continually replaced by calling up reserves, and turning these into the blood cell types needed by the body. Claus Nerlov and his colleagues at the European Molecular Biology Laboratory (EMBL) unit in Monterotondo, Italy, in collaboration with researchers from Sten Eirik Jacobsen's laboratory at the University of Lund in Sweden, have now uncovered how an intracellular communication pathway contributes to this process. Because defects in such pathways and in the development of stem cells frequently lead to leukemia and other diseases, the work should give researchers a new handle on processes within cells that lead to cancer. The work is published in this week's online issue of Nature Immunology.