An important source of uncertainty in predictions about global warming is how plants will respond to increasing atmospheric carbon dioxide. Now biologists at the University of California, San Diego have made significant advances toward understanding the mechanism plants use to regulate their carbon dioxide intake.

Arizona farmers receive the same yield/acre, use fewer chemical insecticides and maintain insect biodiversity when they plant the biotech cotton known as Bt cotton, according to new research.

Boston, MA – The prevalence of obesity in the U.S. states has been greatly underestimated. Researchers at the Harvard School of Public Health (HSPH) analyzed data from health surveys, which are used to estimate obesity levels in states. Because people tend to provide incorrect information about their weight and height, especially in telephone surveys, the researchers concluded that estimates of obesity in individual states have been too low, by more than 50%. Their study, which corrects for misreporting in those surveys, appears in the May 2006 issue of the Journal of the Royal Society of Medicine.

Researchers at the University of California, Los Angeles have defined conditions associated with disabling fatigue that persists for years in almost a third of breast cancer survivors, according to a study in the May 1 issue of Clinical Cancer Research.

Biologists have long argued about how birds evolved the ability to fly, because it is not immediately evident what improvement in fitness would result from ancestral, partly evolved wings. Two theories have recently dominated the debate: one postulates that flight evolved in tree-dwelling ancestors that used their forelimbs to help them glide, while the other considers ancestral birds to be terrestrial dinosaurs that developed powered flight from the ground up.

Estimates of increased plant respiration in response to higher global temperatures may be somewhat overstated as they have not taken into account plants' ability to adjust to changing conditions, according to researchers from Oak Ridge National Laboratory.

A new technique devised by MIT engineers may one day help physicians detect cancerous tumors during early stages of growth.