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15 October 2011| NewScientist | 5 KARL AMMANN/NATUREPL.COM/NATUREPL.COM DOCTORS should stop screening for prostate cancer because it does more harm than good. This advice comes more than a decade after the prostate-specific antigen (PSA) test was introduced in the US. “PSA-based screening for prostate cancer has no net benefit,” concludes the US Preventive Services Task Force, which evaluates screening services. The dangers of PSA- based screening include a high rate of false positives, negative psychological effects, and complications associated with diagnostic biopsy and treatment, the task force says. Between 1986 and 2005, 1 million men in the US had surgery and radiotherapy for prostate cancer after a PSA test, but the panel found no evidence this prevented more deaths than “watching and waiting”. However, between 200 and 300 men in every thousand treated developed incontinence or erectile dysfunction. “It’s encouraging to see a real debate on the impact of the PSA test on patient outcome,” says John Semmes of Eastern Virginia Medical School in Norfolk. Watch and wait ANTARCTIC researchers are set to make first contact with lakes deep beneath the continent’s ice – closely followed by second and third contact. Russian, British and US teams hope to find new kinds of life in the lakes, and evidence of how likely the west Antarctic ice sheet is to collapse. Over the next few months a team led by the British Antarctic Survey, based in Cambridge, will set up drilling equipment atop the 3 kilometres of ice that bury Lake Ellsworth. Next year the team will break into the lake by firing a jet of hot water into the ice. Using the melted ice itself in the jet should minimise contamination of the lake. Last year a Russian expedition drilled to within 29 metres of the surface of Lake Vostok, which lies 3750 metres below the icy surface of east Antarctica. They had to stop when winter closed in, but will resume drilling in January. The third project, the US-led WISSARD, will drill into west Antarctica’s Lake Whillans. A sediment core from Lake Ellsworth should tell us when the ice sheet last collapsed, says Dominic Hodgson of the British Antarctic Survey. Ground-up rock will have been deposited while the ice sheet was present, but when it was absent, marine sediment will have been deposited instead. “That provides a marker,” Hodgson says, and will help establish how likely it is that the ice will vanish again. BAS A taste for peanuts Mice have been cured of peanut allergy by attaching the peanut protein that causes allergic reactions to white blood cells outside the body then injecting them back into the mice. This reconditions the immune system so that it no longer reacts to the protein (The Journal of Immunology, DOI: 10.4049/ jimmunol.1100608). Bay of Plenty oil spill Compared with catastrophic tanker spills, the amount of oil released by the Rena cargo ship in New Zealand waters is small, but the spill has been declared the country’s worst marine disaster. Some 130 to 350 tonnes of oil have escaped; almost five times as much remains on board. Virus threatens tigers Wild Amur tigers in Russia are falling victim to a viral infection transmitted by stray dogs. Samples from two tigers have tested positive for the virus, which in a mutated form killed 1000 Tanzanian and Kenyan lions in 1994. The virus can be tackled by vaccinating domestic dogs. Solar link to chills Evidence for a link between extreme winter weather in North America and Europe – including the cold spells of the past three years – and the 11-year solar cycle is growing stronger. An analysis of fluctuations in the sun’s ultraviolet radiation by climate scientists at the UK Met Office suggests a mechanism for how solar activity affects seasonal weather (Nature Geoscience, DOI: 10.1038/ngeo1282). Power of protein Meat lovers, rejoice. Feeding your appetite for protein may curb overeating. Volunteers on a 10 per cent protein diet gained 1 kilogram a month, were hungrier and snacked more than those on a 15 per cent protein diet, who gained no weight (PLoS One, DOI: 10.1371/journal. pone.0025929). –High above Lake Ellsworth– Race to the bottom Moon suit “Prostate screening has no net benefit. There’s no evidence it is better than watching and waiting” “A sediment core from Lake Ellsworth should tell us when the west Antarctic ice sheet last collapsed” NASA isn’t pleased: it is suing the sixth man on the moon after learning that he intended to sell an Apollo 14 camera. Edgar Mitchell says NASA agreed to let astronauts keep some mission mementos. In 1971, he landed on the moon during the Apollo 14 mission. He brought a movie camera home with him that had been on the lunar lander. After ferrying Mitchell and Alan Shepard between the command module and the moon’s surface, the lander was allowed to crash onto the moon. NASA had planned to bring the film back to Earth but leave the camera on the lander, meaning it would have been destroyed too. In June, NASA filed a lawsuit to force Mitchell to return the camera. Mitchell sought to have the case dismissed, but a Florida judge ruled last week that it will go to trial late in 2012. 60 SECONDS –$200 of bushmeat– For daily news stories, visit newscientist.com/news
