the-BA : Science News Digest

Flu jab (image copyright: istockphoto.com)

In the science news this week: Neanderthals speak out, scientists follow flu’s journey around the globe, and why John McEnroe was probably wrong to challenge the umpire about that line call...

Neanderthals haven’t been heard since they died out 50,000 years ago, but this week the Telegraph reported how scientists have managed to recreate their voice. An anthropologist teamed up with a linguist to reconstruct Neanderthal vocal tracts from three 60,000-year old fossils and simulate their speech using a synthesizer.

So far they have only engineered the sound of a Neanderthal saying ‘E’ (which can be heard on the Telegraph website) but concluded that they lacked the ‘quantal vowel’ sounds that underlie modern speech and enable speakers with different sized vocal tracts to understand each other. For example, quantal vowels are needed to distinguish ‘beat’ from ‘bit’.

Whether Neanderthals had fully articulated speech, or simply used grunts, gestures and pre-language, has long been a matter of debate. After carrying out the reconstruction, the researchers concluded that Neanderthals would have spoken but that due to this linguistic difference their speech would have been limited compared to modern humans.
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If you’ve been suffering from the flu, you may be blaming the work colleague who’s been walking around the office coughing and sneezing. They’re just the latest in a long chain of infected individuals however – new research has been investigating how strains of the virus emerge in Asia before migrating around the world to start seasonal epidemics.

It’s hoped the work will help experts select which strains of virus to include in seasonal vaccination, reports the Times. Each year, eight months before the immunisation programme begins, and well before any outbreaks of flu, scientists must decide three strains to include in the vaccine.

In a recent study published in the journal Science, researchers analysed over 13,000 samples of the most common strain of influenza virus collected from around the world in 2002-07. They found that new strains tend to emerge in East and South East Asia, thanks to unique climatic conditions that mean the virus circulates all year round. It is only six to nine months later that the new strains reach Europe and North America, arriving in South America several months after that.
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According to new scientific analysis, we could be in for a rise in sea level of between 80 centimetres and to one-and-a-half metres by the end of the century – significantly more than forecast by the Intergovernmental Panel on Climate Change last year.

The discrepancy is because the processes leading to ‘accelerated’ melting of polar ice sheets as water warmed were not yet understood, and so their contribution wasn't included by the IPCC.

The latest analysis conducted by a UK/Finnish team was presented at the European Geosciences Union annual meeting, reported BBC News. It is based on a computer model linking temperatures to sea levels for the last two millennia. It isn’t the first to suggest the IPCC’s forecast of a 28-43 centimetre rise was too conservative.

The predictions have worrying implications for low-lying countries such as Bangladesh – where 80 to 90 per cent is within a metre or so of sea level, and millions face losing their homes and livelihoods.
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Meanwhile, the Guardian took a look closer to home. In places such as Norfolk people face difficult decisions over whether it is viable to keep improving sea defences and trying to keep the water at bay, or whether the time has come to accept the loss of land and all that entails and retreat inland.
(Read more... )
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In other news reminiscent of Hollywood sci-fi films, the American army has developed a robotic suit that can greatly increase a human’s strength and endurance.

The XOS lightweight aluminium exoskeleton matches the movement of the wearer and is designed to have comparable agility. It enables the person wearing it to easily lift more than they weigh.

While problems such as the creation of a mobile power supply that can last sufficiently remain, the US military anticipate taking delivery of early prototypes early in 2009, and deploying refined versions within eight years.

Initially, the XOS could result in quicker supply lines and fewer injuries for soldiers lifting heavy weights, while later it might be used in combat to carry heavier weapons or wounded colleagues.
(See the XOS in action on BBC News)
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UK researchers have made new advances with graphene – the substance some predict to be the leading contender to one day replace silicon as the basis for computing. They used it to create a transistor just one atom thick and ten wide, reported NewScientist.com.

While the number of transistors on a chip currently doubles roughly every two years – a rate of progress that has been true for 40 years - silicon is reaching the limits of its capabilities. The newest chips have features just 45 nanometres across, but silicon is unable to form stable structures below 10 nanometres in size.

The transistors created by the University of Manchester team using graphene are some of the smallest ever. The researchers overcame a major obstacle to do this: the material usually lacks the switchable conductivity essential for transistors to control electric current. By cutting small ‘quantum dots’ of graphene just a few nanometres across, they were able to give it this property, making use of quantum effects that become dominant at this scale.

The application of a magnetic field turns these dots into switchable transistors, as trapped electrons are able to flow again. The smallest dot found to work as a transistor was just one nanometre wide.

The devices differ from other prototypes of this size range because they are able to work at room temperature, whereas others usually require supercooling using liquid gas, while their other big advantage is that they are created in the same way as silicon devices, by etching from larger pieces of material. However, manufacture on a practical scale remains a challenge.
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The Guardian reported that publication of a human genome sequence that took just a million US Dollars and two months to complete heralds the next step towards an era of mass genome sequencing. In comparison, the first publicly-funded genome sequencing in 1990 took ten years to produce a rough draft and cost three billion US Dollars.

Genome sequencing may one day be so cheap that it can be conducted routinely at birth, providing individuals with advice about what diseases they are susceptible to. This could enable them to make appropriate lifestyle choices or ensure that they have early access to any necessary monitoring and treatment.

However, not everyone will wish to know about their entire genetic predisposition even if it is possible and cheap. Professor James Watson, whose genome was sequenced, is a good example of some of the issues that can be raised. He requested that the region around a gene called APOE – known to play a role in Alzheimer’s – not be sequenced, as he didn’t want to be worried by a potential result, and he did not want it made available to his employers.
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Scientists are hopeful that a new cloning technique could be used to conserve endangered species such as the northern white rhino (one of the world’s rarest animals), the giant panda, the African wild dog, the Ethiopian wolf and the pygmy hippo.

The Independent reported that the Medical Research Council’s human reproductive sciences unit is going to work closely with Edinburgh Zoo on breeding technologies and a new ‘Institute for Breeding Rare and Endangered African Mammals has been set up in Edinburgh to bring expertise and resources together.

Pioneering experiments will be trialled for the northern white rhino – of which just three or four animals are thought to remain in the grasslands of north-east Africa. The technique will involve reprogramming skin cells taken from animals in captivity or temporarily captured in the wild, so that they revert to an embryonic state and can develop back into any of the body’s specialised cells, including sperm and eggs.

The reprogramming method has been extensively and successfully tested on laboratory mice and Paul de Sousa, a stem cell expert at Edinburgh University believes that it should be possible to use the technique on the northern white rhino, and others, since all mammals appear to share the genes that are involved in reprogramming skin cells.

By mixing the northern species’ cells with embryos provided by a less-endangered close cousin, the southern white rhino, the scientists hope that some of the resulting chimeric offspring (that would contain a mixture of cells from both sub-species) would grow up to produce the sperm and eggs of the northern white rhino and hence boost the animal’s dwindling gene pool.
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Other news in brief:

Footage of Coronal Mass Ejections – that shoot huge amounts of ionised hydrogen and helium from the Sun’s surface – captured by Nasa’s Stereo orbiters can be viewed on BBC News Online.
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Australian researchers have discovered how to reverse abnormal vessel growth in tumours and make them more susceptible to attack by the body’s immune system.

Dr Ruth Ganss, from the Western Australian Institute for Medical Research, who reported the work in Nature said: ’It’s the uncontrolled growth of blood vessels and the formation of abnormal blood vessels inside tumours [a process called angiogenesis] that “feed” them, allowing them to grow and stopping the immune system from wiping out the tumour.

’What we’ve shown is that RGS5 is a master gene in angiogenesis and that when it is removed, angiogenesis reverses and the blood vessels in tumours appear more normal. Importantly, this normalisation changes the tumour environment in a way that improves immune cell entry, meaning tumours can be destroyed and improving survival rates in laboratory tests.’
(The Telegraph)
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The latest major set of additions to the Darwin Online project include his first formulation of the theory of natural selection from 1842 (including afterthoughts, footnotes and crossed-out text) and correspondence from his wife on religious faith. They are available to view online free of charge.
(The Guardian)
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The Telegraph described advances in ‘Virtual Paleontology’, where powerful X-ray technologies coupled with modern software are enabling scientists to see inside fossils in exceptional detail.

Synchrotron machines (that accelerate electrons in a circle) produce bright beams of X-rays that allow more precise pictures to be taken than previously possible. These can then be turned into stunning 3D images – for example, of bones of embryonic dinosaurs within petrified eggs, and of previously invisible invertebrates captured in amber.
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And finally…

One of the most famous moments in tennis history, and certainly one of the most quoted, is when John McEnroe disputed an umpire’s line call, yelling: ‘You cannot be serious man! That ball was on the line!’

Now, following analysis of 1,473 Hawk-Eye (the electronic line-calling system) challenges made by 246 players or doubles in 2006 and 2007, a researcher from the University of Sussex has concluded that the line judges are significantly more accurate than the players, who only get it right 40 per cent of the time.

However, Dr George Mather suggests that players should use their full quota of challenges, because the judges still make a significant number of mistakes. He suggests the players may want to focus on the base and service lines as these are the ones judges are most often wrong about – although there is also a greater chance of the player getting these wrong.
(The Times)