USA

Calling the post "too important to leave vacant any longer," President Bush installed controversial John Bolton as US ambassador to the United Nations at a White House ceremony. The president cited his constitutional authority to bypass the Senate, where Democrats have delayed Bolton's confirmation by demanding more information about his record as the senior US arms-control diplomat. The recess appointment, made with Congress on summer break, allows Bolton to serve until January 2007, when a new Congress is sworn in. Democratic critics were quick to criticize the end run.

As two Discovery astronauts worked to replace a 600-pound gyroscope used to steer the International Space Station, NASA officials considered whether to undertake an unprecedented repair to the shuttle's heat shield. The decision revolves around what to do after an in-flight inspection revealed that two bits of filler material protrude between thermal tiles on the shuttle's underside. Engineers must decide if these could overheat on re-entry and whether attempting a repair is necessary.

After a few postponements, Bush appeared Sunday at the National Boy Scout Jamboree near Bowling Green, Va., where an estimated 50,000 members, their leaders, and visitors were buoyed by his words at the end of a difficult week. Four leaders were electrocuted by a power line at the beginning of the 10-day jamboree and, later, 300 scouts were overcome by the heat. Bush urged the boys to live up to the ideals that the leaders who died exemplified.

Minnesota became the final state to adopt a 0.08 percent blood-alcohol level to measure drunkenness in motorists. Until Monday, Minnesota had used a 0.10 percent limit. The National Highway Traffic Safety Administration says the lower limit reduces drunken driving deaths on average by 5 to 8 percent.

Hurricanes are growing in intensity because of rising ocean temperatures, according to a Los Angeles Times account of research presented online in the journal Nature. Based on five decades of data, meteorologist Kerry Emanuel says the duration and wind speeds of storms have increased 50 percent as a factor of human-induced global warming and natural ocean-temperature oscillations.

Immigration and Customs enforcement agents arrested 528 alleged street gang members, most of whom are illegal immigrants, in 27 states over a two-week period, officials said Monday. The crackdown, part of Operation Community Shield, is "just getting started" according to one official. So far, the campaign has made 1,057 arrests as part of the sting.