COSTELLO: Fifty-one minutes past the hour. Here's what you need to know to start your day.</s>COSTELLO (voice-over): New video just in from Libya showing rebels taking control of the capital city of Tripoli. New explosions rocking leader Moammar Gadhafi's compound. No one knows for sure where Gadhafi is right now. Three of his sons in custody. Hurricane Irene churning near the Caribbean islands. Forecasters say Irene could dump up to 20 inches of rain in Haiti and the Dominican Republic. Irene could hit the United States by the end of the week. The families of two American hikers sentenced to eight years in prison are urging the Iranian government to show compassion and free those two men. Josh Fattal and Shane Bauer were convicted of espionage and illegal entry into Iran. They were arrested more than two years ago. A Missouri teachers union is suing the state over a new law that prevents them from using the social networking site, Facebook, to connect with students. They say it violates their constitutional rights. The law takes effect on Sunday. A possible breakthrough that could lead to an effective treatment for Lou Gehrig's disease. Northwestern University researchers say they have found that the basis of the disease is a malfunctioning protein recycling system in the neurons of the brain and the spinal cord. These neurons become severely damaged when they can't repair or maintain themselves. And investors bracing for another potentially rocky week in the markets after steep losses across the board last week. Right now, U.S. stock futures for the Dow, NASDAQ and S&P; 500 are all trading higher ahead of the opening bell. Investors getting a boost from a dip in oil prices overnight.</s>COSTELLO (on-camera): And that's the news you need to know to start your day. AMERICAN MORNING back after this.
Scientists Cite Gains On Lou Gehrig's Disease