the-BA : Science News Digest

Blackbird (image copyright: istockphoto.com)

In the science news this week: stunning images both of the instant a star died and of the moment a human egg was released during ovulation, a 2,000-year-old seed has become the oldest ever grown successfully, and an early warning system could identify birds at risk of population decline. Plus, new research suggests humans should be let off the hook for hunting woolly mammoths to extinction...

New research has revealed that there were actually two kinds of woolly mammoth, reported the Telegraph. Scientists previously assumed there was just one, as there was no fossil evidence suggesting otherwise. The finding challenges assumptions that humans were responsible for wiping them out.

The new insight, published in the Proceedings of the National Academy of Sciences, comes as a result of analysis of the animals’ mitochondrial genome – the first time scientists have dissected the structure of an entire population of extinct mammal using genetic information from mitochondria (the ‘power plants’ within cells).

‘The population was split into two groups, then one of the groups died out 45,000 years ago, long before the first humans began to appear in the region,’ said lead researcher Dr Stephan Schuster of Penn State University. ‘This discovery is particularly interesting because it rules out human hunting as a contributing factor, leaving climate change and disease as the most probable causes of extinction.’
--------------------

As atmospheric carbon dioxide levels rise, the ocean is becoming more acidic. BBC News described how natural carbon dioxide vents on the sea floor are providing scientists with some insight as to how this will affect marine life in the future.

The Intergovernmental Panel on Climate Change predicts that without measures to reduce carbon emissions the pH of the ocean could fall as low as 7.8 by 2100. The current global average is 8.1 – a fall of about 0.1 since the industrial age began.

This increasing acidification of the sea will have an impact on creatures that use calcium carbonate to construct their shells or skeletons because its concentration falls as acidity increases. The UK scientists who reported their observations in Nature said that at pH 7.8 to 7.9 the number of species present was down 30 per cent compared to neighbouring areas. There was no coral present around the vents, and snails were seen with their shells dissolving. However, seagrasses that were maybe benefiting from extra carbon in the water thrived.

Research leader Jason Hall-Spencer, a previous BA Award Lecturer from the University of Plymouth, said: ‘It's clear that marine food webs as we know them are going to alter, and biodiversity will decrease. Those impacts are inevitable because acidification is inevitable - we've started it, and we can't stop it.’
--------------------

In the Guardian: A number of environmental groups, including the National Trust, RSPB and WWF, have challenged the government’s plans for a 15 billion pound tidal barrage across the Severn. While it would provide about 5 per cent of the UK’s annual electricity needs – helping Britain meet EU targets which say 40 per cent of the country’s electricity should come from renewable resources by 2020 – the coalition says that it comes at too high an environmental cost.

The group, who commissioned their report from the economics consultancy Frontier Economics, say the project would destroy nearly 86,486 acres of protected wetlands and that projected costs don’t take account of the cost of land acquisition or the creation of new wildlife habitats to compensate for those lost. The government’s environmental advisors, the Sustainable Development Commission, conducted a study last year that found in favour of the barrage on condition that lost wetlands be compensated for elsewhere.

The latest report also suggests that the carbon dioxide emissions produced during material transport and construction of the barrage would be 5 million tonnes each. The government is currently conducting its own feasibility studies.
--------------------

A 2,000-year-old date palm seed has become the oldest ever seed to be successfully germinated, reported the Independent. It was among three seeds recovered during archaeological excavations in the 1960s of the King Herod-fortified Jewish fortress of Masada near the Dead Sea.

The seed was planted two years ago to test whether it was viable and radiocarbon dating confirmed that it belonged to the period just before Masada’s siege and destruction by the Romans in AD72.

Dr Sarah Sallon of the Hadassah Medical Organisation in Jerusalem, who led the research published in Science, said: ’The ability of seeds to remain viable over prolonged periods of time is important in preserving plant genetic resources.’

Since discovery, the seeds had been maintained at room temperature. Prior to that they had been buried among the Masada ruins. ‘The Dead Sea is the lowest terrestrial point on Earth and it’s extremely hot and dry. So one of the things that probably helped to preserve the seed is the extreme dryness and heat of this area,’ said Dr Sallon.
--------------------

Roadrunner, a supercomputer built from microchips designed for games consoles, was this week officially crowned the world's fastest computer. Its title came after a test run saw it perform a million billion calculations per second.

The manufacturers put this feat in context by explaining that if 6 billion people did one sum a second on a calculator, it would take 46 years to do what Roadrunner could do in a day. In comparison, the Cray 1, the world’s first supercomputer built in the mid-1970s, would take 1,500 years to complete a calculation Roadrunner would take just two hours to perform.

Roadrunner has now been moved to the Los Alamos National Laboratory where it will help the military assess the safety and readiness of the US nuclear arsenal. However, before it begins this task it will spend six-months tackling scientific problems such as how HIV vaccines should best be administered, whether firing laser beams into plasmas will trigger nuclear fusion and mapping the region of the human brain that controls vision, as well as testing climate change models.
(Read more in the Guardian)
--------------------

The Guardian also reported that scientists have developed an ‘early warning system’ to identify birds that could be at risk of becoming endangered. At least a fifth of British birdlife is already at serious risk and it is hoped the new system can give conservationists a head start in protecting birds at future risk, such as greenfinches and the common blackbird.

Gavin Thomas, a biologist at Imperial College London used genetic records to construct a family tree of the nation’s birdlife. The first detailed record of its kind revealed that 93 per cent of British birds are related, and that endangered birds appeared to be grouped – suggesting that they shared traits that made them vunerable to population decline (such as low fertility rates or similar dietary or habitat needs).

Several close relatives of the blackbird, including the song thrush, are on the endangered list, suggesting it could also be at risk of declining in the future. Likewise, the greenfinch is closely related to the endangered linnet and bullfinch.
--------------------

For the first time ever, astronomers have observed the moment at which a star explodes into a supernova. Combining data from both ground-based and orbiting telescopes to compose a series of images, the scientists captured a dramatic ultraviolet flash.

’We believe that this light, emanating from deep within the star, was generated after its core collapsed and compressed the gas surrouding it to around one million degrees Kelvin,’ said Dr Stephen Justham of the University of Oxford’s Physics Department. ‘This flash occurred about two weeks before it was detected as a normal supernova.’
(The Daily Telegraph)
--------------------

After two years of deliberations and negotiations, astronomers have finally decided on a new official classification for Pluto, fomerly known as the ninth planet before its controversial demotion in 2006. It will now be known as a 'plutoid'. There are now two known plutoids in the solar system – Pluto and Eris – and the International Astronomical Union, who approved the classification this week, expect more will be named as new objects are discovered.

The Telegraph reported the following statement from the IAU: ‘Plutoids are celestial bodies in orbit around the sun at a distance greater than that of Neptune that have sufficient mass for their self-gravity to overcome rigid body forces to[sic] that they assume a near spherical shape, and that have not cleared the neighbourhood around their orbit.’
--------------------

Other news in brief:

Archaeologists in Rihab, Jordan believe they may have discovered the world’s oldest Christian church – a cave dating to AD33-70.
(BBC News)
--------------------

Spanish researchers have proven that it is possible to design special metamaterials that can be used to produce an acoustic cloak that makes sound waves flow around an object.
(Daily Telegraph)
--------------------

Professor Robert Langer, whose research into biomaterials has led to more accurate and controlled drug delivery in patients – with a significant impact on the ability to fight cancer and heart disease – has been rewarded with the prestigious Millenium Technology Prize. The 800,000 euros award is given every other year for a technology that ‘significantly improves the quality of human life, today and in the future’, and is seen as an unofficial Nobel Prize for technology.
(BBC News)
--------------------

Historical fishing records have revealed that shark numbers in the Mediterranean Sea have dropped dramatically in the past few decades. Among the worst affected are blue sharks whose population has decreased by 96.5 per cent, and mackerel sharks that have declined by an estimated 99.99 per cent. Overfishing is a particular threat to sharks because they grow slowly, reproduce late and produce few young.
(The Guardian)
--------------------

Other interesting items this week:

Gynaecologist Dr Jacques Donnez captured amazing footage of the moment a human egg was released from an ovary during ovulation. They are the clearest pictures ever taken of the event that is so crucial to human reproduction, and were recorded by chance during a partial hysterectomy operation on a 45-year-old woman. See the images at NewScientist.com
--------------------

The Telegraph invited people to participate in the Magical Memory Tour by submitting their Beatles-related memories, and revealed those of some of the UK’s leading scientists. The study is being conducted by scientists at the Leeds Memory Group at Leeds University’s Institute of Psychological Sciences in collaboration with the BA (British Association for the Advancement of Science) to explore autobiographical memory. The results will be announced at the BA Festival of Science taking place in Liverpool in September. Why not join in and add your own memories if you haven’t already done so? You can also explore what other people consider their most-significant memory of the Beatles.
--------------------

The Guardian interviewed six Britons desperate to earn a place as one of the European Space Agency’s new generation of astronauts, asking: ’What makes a person willing to climb inside a huge rocket and wait for someone to light the fuse?’
--------------------

And finally...

Could ‘pedestrian power’ be the answer to some of our energy needs? According to the Times, some engineers think so, and the footfall of trudging shoppers and commuters is about to become the latest source of emission-free energy harnessed to power lightbulbs and other devices in supermarkets and railway stations.

The technology works by using the pressure of feet to compress pads underneath the floor. This drives fluid through mini-turbines that generate electricity.

Engineers have modelled how this could work at Victoria Underground station in London and calculate that the 34,000 travellers an hour could generate enough electricity to power 6,500 lightbulbs.

Similar technology could exploit the energy of passing trains and vehicles: successful trials at a bridge in the Midlands last year used energy converted from trains passing above to power a flood detector. The American military have also tested technology where mini-generators were built into soldiers’ boots.