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.
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.
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
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
Trees find friends in farmers
Farm with sylvan charm
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
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
Space club growsSouth Korea joined the league of
spacefaring nations on 25 August
when its first rocket carrying a
satellite blasted into space. The
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.
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