Technology

“PUMPING” data around a wireless network of sensors – just as blood is pumped around the human circulatory system – could allow the sensors’ batteries to last four times as long.

Sensor networks like the ones used for environmental monitoring are usually “tree-like”. Their branching structure means information gets from A to B quickly, but means devices have to be turned on permanently to co-ordinate the data traffic.

Now IBM’s TJ Watson Labs in New York have come up with a biologically inspired alternative: a “heartbeat” that synchronises the flow of information from node to node around the network. Nodes only turn on when the beat reaches them, saving battery power – but the system is slow because data has to travel all the way around the network.

LOCATION data that lingers in the memory of GPS receivers is proving an unexpected boon for crime-fighters.

London’s Metropolitan Police have used information extracted from satnavs to help investigations into kidnaps, the grooming of children, murder and terrorism, according to a paper by forensic analyst Beverley Nutter, to appear

$1billion. The combined market value of the error pages shown when web surfers try to access non-existent websites

You may think penguins all look the same, but you’d be wrong. A remote-controlled video camera on a South African island can identify individual birds from the arrangement of distinctive black plumage spots on their chests.

The camera – part of a system built by Tilo Burghardt and Peter Barham of the University of Bristol, UK – is hidden at ground level on a path the penguins use daily to reach the sea. If a bird’s chest is clearly visible, image analysis software generates a 2D map of the plumage spots. This can be compared with a database of stored maps to identify individual birds.

The technology is being tested on Robben Island, South Africa, home to some 20,000 African penguins. “The identification rate is now about 98 per

cent accurate,” says Burghardt. (You can see a video of the system in action on the New Scientist website via http://tinyurl.com/4lpjvo.)

The camera should snap every bird on the path at least once each month, helping researchers keep track of the endangered population without resorting to methods such as tagging that can distress or harm the penguins. “You don’t realise how much you affect the birds just by going to within 100 metres of them,” says Barham.

It should also be possible to track the behaviour of individual birds – for example, how male and female birds share chick-guarding and fishing duties. Barham thinks it may even be possible to judge how much a bird has eaten from the way the contents of its stomach stretch out its spots.

PICK OUT A PENGUIN

in the journal Digital Investigation. The data, stored on memory cards or hard drives, can include hundreds of GPS fixes of a user’s movements, including the location of their home and places they have recently visited.

And since some people couple their satnavs to their cellphones, GPS receivers can also contain phone numbers they have called or received calls from, contact lists and text messages – making them a fruitful one-stop-shop for detectives.

Lecturers and teachers could soon have an automated ally in the classroom. An intelligent tutoring system developed at the University of California, San Diego, can analyse facial cues, expressions and head movements to gauge how difficult students are finding a lecture. The system gets it right less than half the time at the moment, but could eventually help create video lectures that run at a student’s own pace.

A new way to fight obesity could soon overcome the need for invasive surgical interventions like gastric banding. In early trials overseen by the Mayo Clinic in Rochester, Minnesota, a small, implantable device that intermittently stimulated the vagus nerve – the nerve which tells the brain that the stomach is full – resulted in a loss of as much as 38 per cent of participants’ excess weight within six months.

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BEST GREEN BUY

Investment strategies that boost wind power yield the cheapest electricity for US consumers

Pete Bethune, after his biofuelled trimaran Earthrace finished a 61-day circumnavigation of the world. Bethune donated his own liposuctioned fat to help power the boat, whose crew overcame pirates, collisions, storms and breakdowns to complete their record-breaking journey (Powerboat-world.com, 27 June)

“Tonight a couple of glasses of champagne will probably sink me”

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Better batteries take heart

They know where you live

www.newscientist.com 5 July 2008 | NewScientist | 23