By Roberta Rampton WASHINGTON (Reuters) - President Barack Obama hopped on a mountain bike that was mounted on blocks and pedaled away, taking part in a science experiment on how to filter unsafe drinking water during an emergency. The invention was the brainchild of Kiona Elliott, 18, and Payton Kaar, 16, two participants in the White House Science Fair, which Obama considers one of his favorite events of the year. ...

LOS ANGELES (Reuters) - Country singer Glen Campbell is set to release what could be his final album as the "Rhinestone Cowboy" singer's health has deteriorated after being diagnosed with Alzheimer's disease two years ago. "See You There," which will be released on July 30, features Campbell singing new versions of old songs, including hits "Galveston, "True Grit" and "Gentle on My Mind," record company Surfdog said on Monday. Campbell, who turned 77 on Monday, performed at the Grammy Awards ceremony in 2012 and completed a farewell "Goodbye Tour" in November. ...

By Karl Plume (Reuters) - Commercial shipping traffic was moving again on the Mississippi River south of St. Louis after a pair of barge accidents that forced the U.S. Coast Guard to close the waterway over the weekend, but navigation remained severely impaired further north. Flooding following torrential rains across the central United States forced the U.S. Army Corps of Engineers to close about a dozen locks on the Illinois River and the Mississippi River north of St. Louis late last week. The U.S. ...

By Harriet McLeod CHARLESTON, South Carolina (Reuters) - Democrat Elizabeth Colbert Busch has a nine-point lead over former South Carolina Governor Mark Sanford, her Republican opponent in the race for the state's open congressional seat, according to a poll released on Monday. In the first independent poll taken since the primary election, Colbert Busch was favored by likely voters 50 percent to Sanford's 41 percent, Public Policy Polling said. Colbert Busch, a businesswoman making her first run for public office, is the sister of television comedian and political satirist Stephen Colbert. ...