Killer magma?

A group of UK geologists suggest that the cause of mass extinctions, such as the one that wiped out the dinosaurs, may not have been caused by meteorites. Instead, they suggest that large eruptions of lava may have contributed to these cataclysmic events. Their research correlates massive lava eruptions to all major extinctions. Volcanic activity releases gases that, in large enough quantities, could have caused prolonged winters followed by carbon dioxide-induced global warming. The researchers are currently studying gases trapped in the volcanic rock thought to have formed 250 million years ago at the time of one mass extinction. They hope to find these gases the cause of the major climate change that wiped out nearly all life on earth.

-Mariana Vidric

Source: University of Leicester news service

An aspirin a day keeps ill effects of meth at bay?

The deleterious effects of drugs such as ecstasy (MDMA) and methamphetamine on the brain have long been debated among scientists. But Dr. Peter Wells, a U of T researcher in the Faculty of Pharmacy, may have provided an explanation of how this occurs.

Turns out an enzyme called prostaglandin H synthase (PHS), which produces many hormones, is to blame. PHS acts as a catalyst-a substance that quickens the pace of a chemical reaction without being consumed-transforming the by-products of amphetamines into free radicals. These are noxious substances that combine with oxygen and attack the proteins and DNA in a living cell to which the brain is particularly susceptible.

To simulate the effects of one big meth bender on the brain, Wells’ team fed the mice four doses of amphetamines, with two hours between hits. Some mice were given aspirin beforehand, which is known to hamper PHS enzymes from producing radicals. Within two weeks, mice that had been fed meth were failing a simple motor coordination task; it took them about six months to recover. Control mice and those given aspirin, on the other hand, remained as fleet of foot as ever.

-Mike Ghenu

Source: Federation of American Societies for Experimental Biology Journal

Blue at 11, baked at 20?

Boys with low self-esteem at age 11 are much likelier to be drug abusers at age 20, sociologists from the University of Florida report. They followed 872 of them over nine years. More than a third of those who have used drugs met criteria for drug dependence nine years on; only three per cent of those who still spurned at age 13 met those same criteria at 22.

-M.G.

Source: Journal of Child and Adolescent Substance Abuse