Science digest 08/15/04

Gene suppressor makes lazy monkeys efficient

Laboratory monkeys that started out as careless procrastinators became super-efficient workers after injections into their brains that suppressed a gene linked to their ability to anticipate a reward. The monkeys, who had been taught a computer game that rewarded them with drops of water and juice, lost their slacker ways and worked faster while making fewer errors. The government researchers used a new technique to temporarily block a gene, known as D2, that normally produces receptors for the brain chemical dopamine -- a component in the perception of pleasure and satisfaction. The results, reported in the Proceedings of the National Academy of Sciences, could shed light on mental illnesses that involve motivation, such as obsessive compulsive disorder and mania.

Labs finds preference for matter over antimatter

Researchers at the Stanford Linear Accelerator Center in California have observed a dramatic difference between the behavior of matter and antimatter, providing a crucial insight into one of the key questions of physics: Why is there matter in the universe? Theoreticians agree the Big Bang that created the universe produced equal amounts of matter and its exotic counterpart, antimatter. Unfortunately, the two are converted back into energy in an explosion when they come into contact. The accelerator flings electrons and their antimatter counterparts together at high speeds, creating exotic particle pairs called B mesons and anti-B mesons, which decay into other particles, producing matter and antimatter. But after sifting through more than 200 million pairs of mesons, the team found 1,600 particles whose decay produced 13 percent more matter than antimatter. Though the effect is rare, it helps to explain why there was matter left over after the Big Bang, said physicist Fred Gilman of Carnegie Mellon University. "It only takes a little tiny difference overall to make it so that the universe now is made out of matter," he said.

-- From wire reports