* Cretaceous chill: Fossil evidence implies that dark skies and plunging global temperatures may have helped kill off the dinosaurs after a giant asteroid impact.

* A protein in breast milk can eliminate warts, a Swedish team reports. The compound, called Hamlet, also seems effective against certain cancer cells. 

* Roads, buildings, parking lots, and other solid structures in the U.S. cover an area the size of Ohio, contributing to urban heat and reducing water quality, the NOAA reports.

* A computer virus infects British cell phones. Although the infection proves harmless, it shows how vulnerable mobile phones really are.

* FDA approves the marketing of leeches as a medical device by a French firm. The animals are used to remove pooled blood after skin grafts and reattachment surgery.

* Researchers inject female rats with a hormonelike drug that makes them three times friskier in the presence of male rats—a possible female Viagra.

* London conservationists seek sperm donations from zoos to provide a genetic lifeline for the endangered Amur leopard, Amur tiger, and Sumatran tiger.

* A presidential commission unveils a major overhaul of NASA with more emphasis on basic exploration and cooperation with private space ventures.

* The United Nations urges protection of the habitat of the 700 mountain gorillas remaining in Central Africa after reports of the destruction of critical Congolese forests.

* Adult skin cells can be transformed into the precursors of nerve cells, say U.K. researchers. Further experiments could lead to new treatments for Parkinson’s disease.

* Physicists perform a simple type of teleportation, transferring the quantum characteristics of one atom onto another atom at a different location.