Coral reefs, like tree rings, are natural archives of climate change. But oceanic corals also provide a faithful account of how people make use of land through history, says Robert B. Dunbar of Stanford University.

In a study published in the Feb. 22 issue of Geophysical Research Letters, Dunbar and his colleagues used coral samples from the Indian Ocean to create a 300-year record of soil erosion in Kenya, the longest land-use archive ever obtained in corals. A chemical analysis of the corals revealed that Kenya has been losing valuable topsoil since the early 1900s, when British settlers began farming the region.

Up to 15 percent of couples of childbearing age struggle with the heartache of infertility. Now there is the promise of new hope with Cornell researchers' identification of a mutation in a gene that causes male infertility in mice. Because this is the first time that a dominant mutation that leads specifically to infertility in a mammal has been discovered, the researchers say they can now look for similar mutations in the DNA of infertile men.

Bacterial infections caused by Gram-negative bacteria such as Escherichia coli are frequently resistant to two or more antibiotics (multi-drug resistant). Because introduction of new antibiotics will not eliminate the problem of multi-drug resistance (mdr), mdr type infections constitute a major health threat, especially to patients that acquire such infections nosocomially. The manner by which mdr develops has become an area of intense research and the recent investigations conducted by an international group consisting of American, Portuguese and French scientists have identified the genetic sequence of events that lead to mdr phenotypes of Gram-negative bacteria.

A study of how the brain of a premature infant responds to injury has found vulnerabilities similar to those in the mature brain but also identified at least one significant difference, according to neuroscientists and neonatologists at Washington University School of Medicine in St. Louis.

Scientists have known for more than a decade that individuals with a certain gene are at higher risk for developing Alzheimer's disease. Now a new study helps explain why this is so.

The research, led by scientists at the Oklahoma Medical Research Foundation (OMRF), has uncovered a molecular mechanism that links the susceptibility gene to the process of Alzheimer's disease onset. The findings appear in the April 11 issue of The Journal of Neuroscience and may lead to new pathways for development of Alzheimer's therapeutics.

The two most prevalent forms of genetic mental retardation, Fragile X and Down syndromes, may share a common cause, according to researchers at Stanford University School of Medicine. The problem, a crippled communication network in the brain, may also be associated with autism.