Atmospheric warming in coming decades could delay the recovery of Earth’s ozone layer.

 While tamoxifen can halve the risk of breast malignancies in cancerfree women, it also poses some serious risks—at least in women over 50. 

Researchers have identified the bacterium causing an unusually virulent coral disease.

A common operation to reduce blockage in the carotid artery carries greater risks of stroke than previously thought.

Spherical clusters of polymer molecules in a mixture of water and supercritical carbon dioxide can act as reaction vessels for enzymes.

A century-old economic model may help ecologists understand how two species can develop a mutually beneficial relationship.

By preventing the growth of butterfly wings and beetle horns, investigators can increase the size of other developing body parts.

Quantum effects do not necessarily rule out the possibility of traveling back in time.

Research Notes

Archaeology

Cutting-edge pursuits in Stone Age 

Human ancestors made sophisticated stone tools, displayed advanced hunting skills, and created symbolic artwork at least 200,000 years ago in the Middle East.

A chemical analysis pushes back direct evidence for tobacco smoking by Native Americans to between 1715 B.C. and A.D. 105.

Biomedicine

Gene therapy for breast, ovarian cancer 

Hyperactivity of a gene implicated in breast and ovarian cancer was dampened by injections of another gene.

Raspberries are suggested to ward off a cancer of the digestive tract.

Low doses of arsenic may prove helpful in treating people suffering from leukemia.

Chemistry

Friends, elephants: Lend me your ears 

Elephants appear to use secretions from glands behind their ears to communicate with each other.

A violin’s sweet sound may depend on the wood's finish.

Certain fire extinguishers can smother flames with a foamy layer of soap.

Butterflies may be more capable of learning than pollination biologists have thought.

Physicists find surprises when they probe the behavior of electrons inside tiny semiconductor structures called quantum dots.