26 June 2010 | NewScientist | 5

to a level up to 0.9 on a visual acuity scale, in which 1 represents perfect vision, reports Graziella Pellegrini at the University of Modena in Italy (The New England Journal of Medicine (DOI: 10.1056/nejmoa0905955).

Most of the patients had burns in only one eye, so Pellegrini’s team was able to treat them with corneal stem cells extracted from their good eye.

Harvested from the limbus, a disc surrounding the iris, the stem cells restored transparency to corneas that had become opaque via the destruction of the damaged eye’s store of corneal stem cells.

Greenhouse junkRISING sea levels, vanishing glaciers and earlier blooming of flowers are among the well-documented effects of climate change. An increase in space junk can now be added to that list.

The upper layers of the atmosphere have a braking effect on defunct satellites and spent rockets, eventually causing them to drop out of orbit and burn up. Arrun Saunders and Hugh Lewis, at the University of Southampton in the UK, studied the orbits of 30 satellites over the past 40 years, and recorded a gradual increase in the time they remain in orbit. They attribute this to the cooling and reduced density of the upper atmosphere caused by increasing carbon dioxide levels.

The researchers calculate that the atmosphere is reducing in density by 5 per cent every decade at an altitude of 300 kilometres. “The lower molecular braking means debris can remain in orbit up to 25 per cent longer,” says Lewis.

This raises the risk of collisions with satellites and makes it more hazardous to launch spacecraft. Space agencies may need to double the amount of debris they plan to remove from orbit, the researchers say. They presented their work at a conference in Boulder, Colorado, last week.

Empty victory?MONSANTO is notching it up as a victory, but whether an end to the ban on the firm’s genetically modified alfalfa will actually lead to the seeds being sold is unclear.

In 2007, organic farmers sued Monsanto, winning an injunction that prevented the firm selling its “Roundup Ready alfalfa”. The farmers argued the alfalfa had not been properly checked by the US Department of Agriculture (USDA) for its environmental impact.

Monsanto appealed, and on Monday the Supreme Court ruled that the lower court had been

“unjustified” in imposing its ban. However, it also ruled that the USDA had broken the law by allowing the seeds to be sold in 2005 in the first place. This means the GM alfalfa cannot be sold until the USDA carries out an impact

assessment. “That could take years,” says John Bianchi, a spokesman for the Center for Food Safety in Washington DC, which is representing the farmers.

“A court was ‘unjustified’ in banning Roundup Ready alfalfa, but the seeds must still be investigated”

THE fate of whale species was being negotiated behind closed doors this week.

“I think it’s fair to say that key governments are viewing it as a make-or-break time,” Sarah Duthie, of Greenpeace, told New Scientist, speaking from the annual summit of the International Whaling Commission (IWC). “It’s difficult to see how negotiations will continue if there are still fundamental differences that can’t be resolved by the end of the week.”

In an attempt to do just that, IWC chair Christian Maquiera and vice-Chair Anthony Liverpool have put forward a new proposal. It eliminates certain loopholes in the so-called ban on commercial

whaling – including one that allows Japan to hunt whales for “scientific research”. While this aspect of the new proposal gets the support of NGOs like Greenpeace, other elements are highly controversial.

For instance, the text suggests quotas for all hunted species, including some endangered ones. According to Maquiera and Liverpool, their proposal would lead to 14,000 fewer whales killed in the next decade, compared with the number of whales that would be killed if catch rates continued at 2009 levels.

But Greenpeace and WWF remain staunchly opposed to any hunting of endangered or vulnerable species. “We are all waiting to see if there is a new proposal,” says Duthie.

Lose loopholes, consider quotas

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Cancer link trashedCellphone masts have been cleared of any link with childhood cancer by a study of 7000 British children – the largest study of its kind undertaken. Children who developed cancer between 1999 and 2001 were no more likely to have been born near a mast than healthy children (BMJ, DOI: 10.1136/bmj.c3077).

Halfway to PlutoThe first mission to Pluto has passed a milestone. On 14 June, the NASA spacecraft New Horizons had covered half the distance to the dwarf planet. Despite New Horizons being the fastest object ever launched from Earth when it departed in January 2006, it will still take another five years to arrive at Pluto.

Female ‘Viagra’ flopsA drug designed to boost female libido was rejected last week by a panel from the US Food and Drug Administration. It concluded that flibanserin, developed to raise sexual desire in the brain, doesn’t provide enough sexual satisfaction to offset the possible side effects of using it, which include fainting, dizziness, depression and appendicitis.

Ten-year savings planJust 10 years – that’s the time required to save our closest cousin from extinction, say the IUCN and the Wildlife Conservation Society. They announced this week that east and central African nations have devised a plan that could – if implemented – protect 96 per cent of eastern chimpanzees.

The ol’ swoop ’n’ skimNASA’s Cassini spacecraft has performed a daring manoeuvre – skimming through the upper atmosphere of Saturn’s moon, Titan, at a speed of 5.9 kilometres per second. The goal was to get close enough to the moon to see if it has its own magnetic field, which could signify an ocean beneath its icy surface.

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