From the American Association for the Advancement of Science’s Annual Meeting 2005 in Washington D.C. Mike Ghenu reports on some of the latest ideas
Saliva drug test to come
A credit-card-sized kit that analyzes tiny amounts of saliva may one day replace uncomfortable urine or blood tests as a way to detect drug use, HIV, or agents such as the bacterium Bacillus cereus, a cousin of anthrax. This is because the composition of saliva closely mirrors that of blood. Researchers led by Daniel Malamud, of the University of Pennsylvania, have developed a small sponge that collects tiny amounts of saliva from a subject’s mouth. The fluid is analyzed in a portable kit through a series of chemical reactions, producing results in about an hour. Malmud’s team is now working to integrate the different tests into one device.
We are warming the oceans
“The debate about whether or not there is a global warming signal here and now is over-at least for rational people,” said Tim Barnett, a marine physicist from the University of California in San Diego. Barnett and other researchers fed weather data into computer models of ocean circulation to estimate human-caused warming of the world’s oceans. Their predictions confirmed measured ocean temperatures with a confidence level exceeding 95 per cent. Ruth Curry, a researcher at the Woods Hole Oceanographic Institution, added that increasing ocean temperatures and the melting of the Greenland ice sheet is causing global sea levels to rise at a rate of about 20 centimetres per century.
Fixing our fisheries
New research shows that overfishing harms fish stocks in two ways. First, it eliminates the highly-productive larger and older fish from the population, which produce up to ten times as many larvae as the smaller youngsters. Second, it gives an evolutionary advantage to smaller and slower-growing fish, permanently altering the genetic diversity of fish stocks. Larry Crowder, marine biologist at Duke University, suggested zoning oceans to create marine reserves to protect the larger individuals from fishermen’s nets. That is the approach taken by Australia to protect the Great Barrier Reef-a third of which is permanently out-of-bounds to fishing and other human activities.
