SCIENTISTS have discovered why some lucky people manage to spend their hols unmolested by mosquitoes while others are bitten down to their last drop of plasma.

It’s all due to your smell, say researchers at the University of Aberdeen, who hope that their discovery will point the way to a new generation of human-derived repellents. They have discovered that mozzies find the smell of certain people utterly repulsive. “They emit unattractive chemicals that mask their otherwise attractive odours,” says Professor John Pickett.

The researchers used a form of gas chromatography to isolate the chemicals that mosquitoes find a turn-off. Now they are transforming them into a long-lasting formulation that may be sprayed on to clothes.

They hope that the human repellent will also work on other insects such as ticks. This could boost the battle against diseases such as dengue and yellow fever as well as malaria.

Human-derived repellent should also help the many holidaymakers who are allergic to traditional repellents such as DEET. These don’t actually repel; they attempt to block the mosquitoes’ sensors so that they can’t locate you.

In future, the mozzies will know where you are, but they’ll wish you weren’t there.

Puzzling purchase

DON’T try doing brain puzzles before shopping — you could overspend, says a study in Applied Cognitive Psychology.

Chicago investigators have found that people are far more likely to say that they recognise and trust brands after they have solved a series of anagrams. The “Aha!” experience of turning a puzzle into something that makes sense gets mixed up with the experience of seeing a brand, they say. So do avoid doing Su Doku in Selfridges.

Head & Boulders

WASHING young boys with shampoos or soaps containing lavender or tea-tree oils may cause hormonal changes and breast growth, says a small study by the US National Institute of Environmental Health Studies.

The institute investigated after five cases were reported of boys growing breasts when using products made with lavender and tea-tree oils. The symptoms subsided after the products were changed. The institute tested tea-tree and lavender oils’ effect on human breast cells and found that they can mimic oestrogen, the hormone that promotes breast tissue growth, and also cut the activity of androgens, which inhibit breast growth.

Herbal-product industry lobbyists say the results are only preliminary, but the institute says parents should be alert to the possible link.

Fruitful new approach in cancer research

A PEACHY way to block cancer in humans has been found by Israeli agriculturalists who were exploring how to boost the size of their fruit.

They were studying RNaseT2, a substance that can interfere with plants’ pollen tubes and limit a peach tree’s ability to produce fruit. If fewer peaches are produced they grow to be bigger.

RNaseT2 works by blocking the action of actin, a protein in the plant that helps to link cell structures. But actin is also found in the human body and the scientists decided to see how RNaseT2 would affect human cells.

They appear to have struck it lucky. They found that RNaseT2 inhibits the action of the cells responsible for forming blood vessels in malignant cancer tumours, starving them of supplies of nutrition and oxygen.

RNaseT2 doesn’t seem to affect normal cells, so it is believed that it may prevent tumours from growing or spreading around the body, but without the severe side-effects of the current treatments, radiation and chemotherapy.

In laboratory experiments using cultures taken from human breast and colon cancers, RNaseT2 inhibited the cells’ ability to form tumour colonies, the team reports in the journal Cancer.

Low-tar, short life

SMOKERS who use low-tar brands as a “healthy” option are far less likely to quit than full-tar fans, says a study by Pittsburgh University of 12,285 smokers. It reports in the American Journal of Public Health that low-tar smokers are twice as likely to keep puffing. They tend to be female and highly educated — but not smart enough to see that life on lights is far riskier than quitting a high-tar brand.

Miss whiplash

COOL-HEADED drivers may be significantly less liable to suffer from whiplash in car accidents than those who are easily startled, claim Canadian physiologists.

The study, by Vancouver’s School of Kinetics, involved suddenly shaking 120 volunteers back and forth while measuring contractions in their neck muscles.

The researchers report, in the Journal of Physiology, that people who were startled by the movements had far more whiplash-like contractions in their neck muscles than those who had been prepared for the shock beforehand.

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