Take a second look at your iced or steaming tea. Guided by scientific experts, three New York City high school students using tabletop DNA technologies found several herbal brews and a few brands of tea contain ingredients unlisted on the manufacturers' package.

Mucosal epithelia do not have any receptors on the outer membrane for the absorption of viruses like hepatitis C, herpes, the adenovirus or polio, and are thus well-protected against pathogenic germs. However, certain viruses, such as the human immunodeficiency virus HIV, still manage to enter the body via the mucous membrane. Just how this infiltration occurs on a molecular level has been a mystery. Three hypotheses were discussed: firstly, that it's caused by mechanical damage to the mucous membrane; secondly, the presence of previously unknown receptors on the mucous membrane cells; and, thirdly, that the viruses are smuggled in via a kind of Trojan horse. Now, for the first time, cell biologists from the University of Zurich have succeeded in identifying the infection mechanism for adenoviruses.

Heliconius butterflies were reared in butterfly houses at the Smithsonian Tropical Research Institute's facilities in Gamboa, Panama. Red may mean STOP or I LOVE YOU! A red splash on a toxic butterfly's wing screams DON'T EAT ME! In nature, one toxic butterfly species may mimic the wing pattern of another toxic species in the area. By using the same signal, they send a stronger message: DON'T EAT US!