Scientists at the University of Colorado and the National Institute of Standards and Technology say they have created a sixth form of matter, the other being gases, solids, liquids, plasma, and Bose-Einstein condensate, first observed in 1995. In Bose-Einstein condensate, atoms cooled almost to absolute zero merge into a single quantum state, in effect forming a single giant particle. Now researchers have achieved something similar with different kind of atom that has to form pairs before it can meld into a condensate. The team says the cloud of supercooled potassium atoms should yield clues to the deep workings of superconductivity, in which materials conduct electricity without any resistance.

A Japanese-U.S. team has reported the successful creation of transgenic zebrafish using sperm genetically modified and grown in a laboratory dish. Getting the immature sperm to grow "in vitro" was the tricky part, and the achievement could have an important effect on gene therapy. Certain genetic diseases could be cured permanently, before babies are conceived, by introducing genetic changes into the sperm—via insertion of a gene-carrying virus—that would then be passed to future generations.