14 August 2010 | NewScientist | 7

in 2003-4 to 18.5 µg/l in 2005-6.Although triclosan can reduce

levels of thyroid hormones in animals, the levels needed to have such effects are much higher than those in consumer products. Sarah Janssen of the US Natural Resources Defense Council says the rise is still a concern: “Though we do not have any human data for triclosan, other chemicals that interfere with thyroid hormones have been shown to cause behavioural changes [in humans] when exposure occurs early in life.”

The US Food and Drug Administration will finish a safety review of triclosan in April 2011.

Autism brain scanTEN minutes in a brain scanner could be all it takes to diagnose autism. So says Christine Ecker at the Institute of Psychiatry, UK, who has developed software that identifies the anatomical signatures of the condition.

Ecker’s team carried out MRI scans on the brains of 20 adult males with autism, 20 with attention-deficit disorder and 20 healthy controls. They used a machine-learning tool called a support vector machine (SVM) – which analyses data and identifies patterns – to identify key differences between the groups, such as in the cortical folding and curvature of the brain. The SVM was then used to build a model to predict whether brain scans fall into the autistic or control group. When the original scans were fed into this model, it diagnosed autism with a 90 per cent success rate (Journal of Neuroscience, DOI: 10.1523/jneurosci.5413-09.2010).

Current diagnosis tools are based on time-consuming and potentially stressful behavioural tests and interviews. Ecker now plans to test her model on children, for whom she predicts more accurate results “because the differences in anatomy between the healthy and autistic brain are more prominent in childhood”.

No easy answerHAS the biggest question in computer science been solved? Vinay Deolalikar of Hewlett-Packard Labs in Palo Alto, California, has released a draft paper titled simply “P ≠ NP”. It could earn him $1 million, as it appears to solve one of the Clay Mathematics Institute’s seven Millennium prize problems.

The P versus NP question concerns the speed at which a computer can accomplish a task such as factorising a number. Deolalikar’s solution implies that many tasks may be fundamentally,

irreducibly complex. An example is the travelling salesman problem, which aims to find the shortest route between a set of cities. If Deolalikar is right, then there is no computer program that can calculate this quickly.

So far, complexity theorists have given a favourable reception to Deolalikar’s draft paper, though scrutiny will intensify when the final version emerges.

“There may be no short cuts to certain complex tasks, such as the travelling salesman problem”

SWALLOWING its pride, NASA says it wants to learn from future commercial missions to the moon – and is willing to pay for the privilege.

The space agency aims to take advantage of the flurry of activity sparked by the Google-funded Lunar X Prize. There are 21 teams vying for the $20 million prize, which will go to the first private entity to land a robotic rover on the moon before the end of 2012.

NASA is seeking any data gathered by commercial landers that would be useful for its own future missions. It has set aside $30 million in total, and says it is prepared to pay up to $10 million per mission, depending on how many “wish-list” technologies a team successfully demonstrates,

such as spacecraft that automatically avoid hazards while landing.

The agency landed both robots and humans on the moon decades ago, but could learn something from designs that incorporate state-of-the-art technology, says David Gump, president of Astrobotic Technology, a team competing for the prize based in Pittsburgh, Pennsylvania. “We went to the moon when TVs had vacuum tubes, cars had fins, and computers had punch cards,” he says.

It’s not clear when – or even if – NASA will send astronauts back to the moon. The White House is trying to cancel plans to return there by 2020, in favour of a mission to an asteroid by 2025, but Congress has yet to approve the idea.

NASA: Spill those X Prize secrets

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Vaccine successA vaccine against rotavirus, which kills 500,000 children each year, could halve the number of infections, trials in Africa and Asia have shown. In Asia, vaccine recipients halved their chances of infection compared with those given a placebo, while in Africa infections were reduced by more than a third (The Lancet, DOI: 10.1016/S0140-6736(10)60755-6).

Flu pandemic is overThe world is no longer experiencing a global influenza pandemic, says a World Health Organization committee, which assessed reports from several countries experiencing H1N1 flu. Although we are now entering a “post-pandemic period”, the H1N1 virus is expected to circulate for some years to come.

Space-fix failureAstronauts on a space-walk outside the International Space Station on 7 August failed to fix a broken cooling pump when toxic ammonia started to leak from a hose connector. They are hoping to have solved the problem after another space-walk on 11 August.

Hunt the frogIt’s a treasure hunt like no other. Over the next few months, teams of researchers will scour 15 countries on four continents for 30 species of amphibians that have not been seen in more than a decade. Conservation International, which is running the search, is confident that at least one of the 30 will be rediscovered.

Arctic’s largest icebergA 260-square-kilometre chunk of ice has broken off the Petermann glacier in north-west Greenland. The iceberg is the largest seen in the Arctic since 1962. Climate change is thought to be behind the acceleration of Greenland’s glaciers towards the ocean, but it’s unclear whether it can be blamed for this latest event.

For daily news stories, visit www.NewScientist.com/news

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