March 4, 1993

Federal regulators are putting television stations on notice: contrary to the past practice of many broadcasters, cartoons like "The Jetsons" and "The Flintstones" can no longer count as "educational and informational" programming. The announcement, issued on Tuesday by the Federal Communications Commission, may not come as news to parents, whose households are inundated with cartoon turtles, rabbits and robots.

In a lustrous finale to one of the most fervid hunts in biology, scientists have discovered the gene behind Lou Gehrig's disease, a neurodegenerative disorder that results in muscle wasting, paralysis and death. And while identifying the gene for an illness is usually just the first step in learning how it works and what happens when it goes awry, in this case the long-sought quarry turns out to be one of the most familiar genes in biomedicine. This familiarity means that potential therapies for the disease may be much closer at hand than had been expected.

The New York City Board of Education reached a consensus in a private session yesterday that a former city schools chancellor, Frank J. Macchiarola, would lead the search for a successor to Chancellor Joseph A. Fernandez, board members said. In choosing Mr. Macchiarola, the board rejected the selection process that led to Mr. Fernandez's appointment, saying that it had been controlled too much by a Manhattan elite and had not been responsive enough to the concerns of parents of the city's schoolchildren.

After overrunning much of a Muslim enclave in eastern Bosnia, Serbian forces rained artillery shells today on thousands of Muslims trapped in the snow-covered region, United Nations officials here said. [ The reports led the United Nations High Commissioner for Refugees, Sadako Ogata, to send a message to the United Nations saying that, even based on the most conservative reports, the Bosnian Serbs were committing a "massacre." She said most of the Muslim victims were found with their throats cut. ] Attack Follows Airdrop The shelling came a day after the United States Air Force tried for a second time in three nights to parachute aid into the enclave, around Cerska, about 20 miles from here. The enclave was once home to both Serbs and Muslims. Last spring the Serbs forced the Muslims from villages in the area, only to be pushed out themselves by a Muslim counteroffensive in December.

AT THE WORLD TRADE CENTER: INQUIRY, LOSS, PRECAUTIONS Three major companies that had planned to move into the World Trade Center before the explosion last Friday are reconsidering the move. The companies had been negotiating for the equivalent of 10 to 15 floors of office space. A1. TEAM OF BOMB SPECIALISTS HUNT FOR CLUES Within hours of the explosion, Federal officials began assembling a team of the nation's most experienced bomb specialists, technicians who probed the wreckage after the terrorist attacks on the United States Marine Corps barracks in Beirut and Pan American Flight 103. B4.