Lunar probes dance to seek water

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  • 29 August 2009 | NewScientist | 7

    Faulty mtDNA inherited from the mother can cause incurable diseases such as MELAS syndrome.

    Mitalipov transferred chromosomes, but not the mtDNA, from the eggs of female monkeys into chromosome-free donor eggs that retained their own mtDNA. The team then fertilised the eggs using standard IVF (Nature, DOI: 10.1038/nature08368). I believe it can be replicated in people very quickly, he says.

    However, gene therapy of this kind that introduces heritable changes could make regulators nervous about human trials.

    Moon dance

    AN INDIAN and a US space probe have performed a delicate dance in lunar orbit, a manoeuvre designed to detect water on the moon.

    Its a unique experiment that can only be conducted by two spacecraft in orbit at the same time, says NASAs Jason Crusan in Washington DC.

    The first evidence of lunar water came in 1994, from radar signals sent by the NASA moon probe Clementine, bounced off the moon and picked up by the probe and receivers on Earth. The reflections hinted that there might be water ice on the surface, but solid proof requires closer listening posts. So on 20 August NASAs Lunar Reconnaissance Orbiter (LRO) and Indias Chandrayaan-1 came within a few dozen kilometres of each other, thanks to tight coordination between NASA and the Indian Space Research Organisation.

    Then Chandrayaan-1 fired its radar at a crater near the moons north pole, and both spacecraft listened to the echoes. The results are still being analysed, but the partners will probably not perform this measurement again: the LRO will soon settle into a lower orbit than Chandrayaan-1 to begin its main observing task.

    Imaging risks

    X-RAYS and CT scans expose a minority of Americans to radiation levels comparable to working in a nuclear power plant. Are such scans worth it?

    Reza Fazel of Emory University in Atlanta, Georgia, and colleagues looked at health insurance records for over 650,000 people who had at least one imaging procedure in a three-year period. Most received low doses of radiation, but around 2 per cent got doses equal to or above the suggested yearly exposure for someone working in a nuclear power plant (The New

    England Journal of Medicine, vol 361, p 849). Fazel says further studies are needed to work out if such medical scans benefit or damage health overall.

    Commenting on the research, radiologist James Thrall at

    Harvard Medical School points to a recent study reporting that medical imaging accounted for a one-year rise in life expectancy in the US between 1991 and 2004.

    Some patients got doses above the suggested levels for someone working in a nuclear power plant

    FARMERS wreck forests, right?

    You would be hard-pressed to find

    anyone who disagreed, but it turns

    out the number of trees on farms

    around the world has been seriously

    underestimated.

    In fact, a study by the World

    Agroforestry Centre (WAC) in Nairobi,

    Kenya, shows that often, the more

    intensive the farming, the more trees

    farmers plant for fruit, medicines,

    fodder crops, windbreaks and fuel.

    The research, presented at the

    World Congress of Agroforestry in

    Nairobi this week, uses satellite

    images to show that almost half of the

    22 million square kilometres of farmed

    land worldwide has at least 10 per

    cent tree cover, most of it previously

    unmapped. About 7 per cent of

    land classified as agricultural had

    more than 50 per cent tree cover.

    Even densely populated

    regions like south-east Asia

    typically have tree cover on more

    than a third of farmland, says study

    author Robert Zomer. Pioneer

    farmers remove trees from the

    landscape, but as intensive systems

    develop, there is an increase in

    planting useful trees, he says.

    Farmers are protecting and

    planting trees, but planners have

    been slow to recognise this, says

    WAC director Dennis Garrity. The

    group wants farmers to be able to

    claim carbon credits for increasing

    forest cover.

    Trees find friends in farmers

    Farm with sylvan charm

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    Engineers for EarthGeoengineering could contribute

    to a million-job green engineering

    sector in the UK by 2050, says the

    British Institution of Mechanical

    Engineers. It says that the British

    government should set aside

    10 million for research into the field

    and should start building artificial

    trees to suck carbon dioxide out of

    the atmosphere.

    Hippy habits die hardForty years after the festival

    that gave them their name, the

    Woodstock generation continue to

    make a mark on US health statistics.

    The Substance Abuse and Mental

    Health Services Administration

    reports that, in 2007, 9.4 per cent of

    people aged 50 to 59 said they had

    used illicit drugs in the previous year,

    up from 5.1 per cent in 2002. In

    people of all other ages, rates of drug

    use are constant or decreasing.

    Tiger hitPoachers have broken into Taman

    Rimba Zoo on Sumatra in Indonesia

    and slaughtered a rare Sumatran

    tiger for its body parts. The tiger,

    part of a conservation project run by

    the Zoological Society of London,

    was killed on Saturday morning after

    being drugged.

    Space club growsSouth Korea joined the league of

    spacefaring nations on 25 August

    when its first rocket carrying a

    satellite blasted into space. The

    Earth-observation satellite,

    however, appears not to have

    reached its intended altitude.

    Counting cancers costCancer doesnt just take a

    human toll, it also creates a financial

    burden. The Lance Armstrong

    Foundation, based in Austin,

    Texas, estimates that there will be

    12.9 million new cancer cases

    across the globe this year, which

    will cost the world $305 billion.

    It predicts there will be 16.8 million

    new cancer cases in 2020.

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

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