Science Digest: Shuttle Launch Delayed Again

Shuttle Again Delayed

CAPE CANAVERAL, Fla. -- Thunderstorms have forced NASA to delay Sunday evening's launch of space shuttle Endeavour.

The launch team came within minutes of sending Endeavour and seven astronauts to the international space station. But storms moving in from the west were in violation of NASA's safety rules, and managers called everything off. They will try again today.

It was NASA's fourth launch attempt over the past month. Saturday's try was foiled by lightning, and hydrogen gas leaks caused two postponements in June.

NASA has until Tuesday, possibly Wednesday, to launch Endeavour with the final piece of Japan's space station lab. Otherwise, it will have to wait until the end of July because of a Russian supply ship, which is awaiting liftoff.

Endeavour holds the third and final segment of Japan's enormous $1 billion space station lab, named Kibo, or Hope. It's a porch for experiments that need to be exposed to the vacuum of space. The shuttle also is loaded with large spare parts and hundreds of pounds of food for the six station residents.

When the shuttle astronauts arrive at the space station, they will make up the biggest crowd ever in a single place in orbit: 13 people. All of the major space station partners will be represented: the United States, Russia, Canada, Europe and Japan.

One American flying up on Endeavour will trade places with the lone Japanese astronaut on the space station, who has been there since March.

-- Associated Press

Alzheimer's Update

For many years, a study tracking nuns belonging to the School Sisters of Notre Dame in Mankato, Minn., has produced provocative theories about the origins and nature of Alzheimer's disease. The study has found that nuns with better education and superior verbal skills in their 20s were less likely to develop Alzheimer's disease decades later, compared with their less intellectually minded sisters.

Research published last week in the journal Neurology provides an intriguing twist to the data. The new study evaluated brain autopsies conducted on 38 nuns, and examined the relationship between the brain features that usually mark Alzheimer's disease and the behavioral symptoms of the disease that some nuns displayed before they died. Alzheimer's is marked by plaques and neurofibrillary tangles in the brain -- evidence that the destruction of brain cells is responsible for the disease.

To the surprise of the researchers, the brains of several nuns who remained intellectually alert and active to their last days had just as many plaques and tangles as nuns who displayed the symptoms of Alzheimer's disease. Nuns who suffered damage to the brain while nonetheless remaining intellectually healthy were again those who displayed superior verbal ability decades earlier.