BOULDER, Colo., July 10 (UPI) -- A U.S. study suggests invisible, reactive gases, not direct emissions of particulates, form the bulk of organic haze observed around the world.

SAN JOSE, Calif., May 23 (UPI) -- The firing of Don Imus and other on-air personalities has launched a discussion of the future of free speech and civil discourse on U.S. airwaves.

NORMAN, Okla., June 17 (UPI) -- The controversial sculpture of a rearing "Mustang" now stands as a memorial to artist Luis Jimenez, who was killed in a freak accident Wednesday in Hondo, N.M.

HONDO, N.M., June 14 (UPI) -- Luis Jimenez, 66, an innovative New Mexico artist who was the first to create sculptures from fiberglass, has died in an apparent industrial accident.