Science: Update

A SIMPLE test for the presence of cholera bacteria has been devised by scientists who are trying to find a way of alerting people to the presence of the microbe before they start falling ill.

Basil Swanson from the Los Alamos National Laboratory in the United States isolated the natural protein within cell membranes that binds to cholera toxin and embedded the receptor in an artificial membrane coating a glass bead. When a cholera toxin molecule binds to the membrane it causes a reaction that emits a red light from the bead. New Scientist reports that the US Army is studying a version of the test to see if it can be used on the battlefield to detect the use of biological weapons.

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A CERAMIC pot thought to be for separating curds from whey might actually have been an early soldering device used to create the intricate metalwork patterns of the Bronze Age. How metalworkers created the delicately soldered knots and scrolls of wire has been a mystery because of the difficulties of creating a flame hot enough to melt metal yet small enough to be handled easily. Jacqui Wood, an archaeologist who runs the Cornwall Celtic Village, a reconstruction of a Bronze Age village, studied a pot with its sides riddled with holes that was thought to be a device for straining curds. The inside, however, was vitrified, indicating repeated heating. When she put a lit candle underneath, a flame 20 centimetres high shot from the top - just the sort of strong yet localised heat needed for soldering metal.

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BREAKFAST CEREALS and bread are being contaminated with increasing numbers of small beetles and mites, according to a report in New Scientist. As the insects become resistant to pesticides, their rising numbers are posing problems for cereal manufacturers.

Ken Wildey of the Government's Central Science Laboratory in York found 81 per cent of the 279 grain stores he surveyed contained mites and 27 per cent were infested with beetles. He also found that 21 per cent of cereal-based foods contained mites, some of which could have been alive as his test killed the insects.