Flashing green snails from the BBC:

A humble marine snail has a unique luminescent shell that brightens its glow, say scientists.

The snail, Hinea brasiliana, produces flashes of green light, which scare away predators.

Its tiny "bioluminescent" body part is lodged permanently within its shell, but the shell amplifies the light, and the faint glow it produces illuminates the whole shell surface.

The findings are published in the Royal Society journal Proceedings B.

Dr Dimitri Deheyn from the Scripps Institution of Oceanography in San Diego, US, led the study.

He specialises in the study of bioluminescent organisms - living things that produce their own light.

It could be the snail's way of saying, 'hey - eat that guy - he's attacking me' Dimitri Deheyn Scripps Institution of Oceanography

Dr Deheyn has worked on glowing snails before, but he was intrigued by this one because, when it retracted into its opaque, yellow shell to avoid a predator, it still glowed.

"The shell actually amplifies the light - making the light source appear much bigger," he told BBC News.

Examining the bright little creature further, the research team discovered that its shell was a far more effective "light diffuser" than the best commercially available product.

"It's also colour-specific," Dr Deheyn explained. "If you shine red light through it, it doesn't work; if you shine blue light it doesn't work.

"It only works for blue-green light that the snail produces."

The team now plans to study the shell in detail, to find out how it works and possibly copy its specialised light-amplifying structure.

Double defence

As well as scaring the predator away, the scientists also think the flashy snail's bioluminescence may act as a second line of defence.

All aglow: more on bioluminescence at BBC Wildlife Finder

The flashes puts "the spotlight" on a persistent predators, such as a crab. This means that the creatures that prey on the crab can see it more easily.

This is a known concept in biology, called the burglar alarm hypothesis.

Dr Deheyn said: "It could be the snail's way of saying, 'hey - eat that guy - he's attacking me'."

Impetus on Iapetus - from the BBC:

Iapetus moon's mighty ridge stirs debate

By Jonathan Amos Science correspondent, BBC News, San Francisco

The mountainous ridge that circles the equator on the Saturnian moon Iapetus is both weird and spectacular.

Discovered in 2004, the icy rim is as much as 20km high and runs fully 1,600km from end to end.

No explanation for its existence has yet won total support; it is a puzzle.

Dr Andrew Dombard and colleagues have now made a compelling case for the ridge being the remains of a huge ring of debris that once orbited Iapetus but which eventually fell on to the moon.

"In my opinion, the ridge at Iapetus, which sits right on the equator, is one of the most amazing features that we've seen in the Solar System," the University of Illinois at Chicago (UIC) scientist told BBC News.

"Imagine standing at the base of this ridge. You'd be confronted with a mountain of ice that is taller than the tallest mountain on Earth and nearly as tall as Olympus Mons on Mars, the biggest volcano in the Solar System.

"And it runs ram-rod straight off in either direction. You wouldn't see it end; you'd just see the ridge disappear over the horizon."

Dr Dombard has been explaining his team's thinking here at the at the 2010 American Geophysical Union (AGU) Fall Meeting, the largest annual gathering in the world for Earth and planetary scientists.

The ridge was first identified in images of the 1,400km-wide moon acquired by the Cassini probe in 2004.

Dr Dombard's group proposes that Iapetus was hit very early in its evolution by another icy body, and that this impact threw an enormous quantity of debris into space.

The researchers argue that this material could then have come together to form a mini-moon or sub-satellite. They liken the situation to the one at dwarf planet Pluto which has a small moon called Charon that was also probably the result of a collision.

Earth's own Moon was almost certainly made this way, too.

But the orbit of the early Iapetus sub-satellite would have decayed over time, the team believes, and tidal forces would have torn it apart to distribute its material in a thick ring around the world.

Over a relatively short period of time, this disc would then have collapsed on to Iapetus to form the ridge we see today.

"Imagine all of these particles coming down horizontally across the equatorial surface at about 400 meters per second, the speed of a rifle bullet, one after the other, like frozen baseballs," said colleague Professor Bill McKinnon from by Washington University in St Louis.

"Particles would impact one by one, over and over again on the equatorial line. At first the debris would have made holes to form a groove that eventually filled up."

Many models have been put forward to explain the line of ice mountains, even ones that involve ring collapse.

Some researchers have proposed that Iapetus could have changed its shape as it began to spin more slowly after its formation.

The stresses from de-spinning, it is said, could have produce warm, buoyant ice in the moon's interior that then rose to the surface at the equator, pushing up its brittle surface to make the ridge.

Dr Dombard told BBC News: "Those models generally invoke global to regional stress fields. Yes you can come up with model where the stresses peak right on the equator, but the stresses 20 degrees off or at the poles may be just as large.

"And so you would expect to see other features on the satellite - not just one feature right on the equator."

Although Iapetus is unique in the Solar System for its ridge, there are hints at another Saturnian moon, Rhea, of perhaps similar processes at work.

Images of Rhea reveal a chain of splotches along its equator where fresh, bluish ice has been exposed on older crater rims.

One suggestion is that these patches could have been uncovered by orbiting material - perhaps a ring - crashing to the surface in the fairly recent past.

From the BBC:

Why haven't we found aliens yet?

By Alex Hudson BBC News

The question of whether or not we are alone in the galaxy is one that has fascinated everyone from mathematicians to conspiracy theorists.

But, if extra-terrestrial life forms are abundant in the Universe - as some people believe - why have they not been in contact?

From Doctor Who to Superman, ET to Marvin the Martian, fiction has regularly brought aliens to Earth as friends or enemies but, as yet, no-one has proved they have ever seen an alien apart from on film or TV.

In 1960, a radio telescope was pointed out into space to listen for signs of extra-terrestrial intelligence, trying to add scientific fact to the question "is anybody out there?"

But 50 years on, nobody knows the answer to it.

"It's probably the most important question there is," says Dr Frank Drake, who was a pioneer of radio astronomy and is considered the father of Seti - the Search for Extra Terrestrial Intelligence.

"What does it mean to be a human being? What is our future? Are there other creatures like us? What have they become? What can evolution produce? How far can it go?

"It will all come out of learning of extra-terrestrials and this will certainly enrich our lives like nothing else could."

Where is everybody?

Back in 1961, Drake created a formula to work out how likely it was that we are alone in the galaxy, a formula which still underpins how experts view the question today.

The so-called "Drake equation" estimates the amount of civilisations able to communicate with Earth. And the figure Drake and his colleagues estimated in 1961 was 10,000.

Many argue over the exact figures, as the equation is based on unknowns. But if that number is anywhere near correct then the more pressing question is why haven't we got any firm evidence of their existence?

This was a question posed by the physicist Enrico Fermi as far back as 1950, saying "where is everybody?" to his colleagues over lunch. It formed the basis of the Fermi paradox which juxtaposes the high estimates of intelligent life and the lack of evidence put forward.

This "great silence" - as it is often referred to - draws attention to the size of the universe and how alone we appear to be. It is a paradox which has yet to be satisfactorily solved.

Astronomers have estimated there to be around 70 sextillion - or seven followed by 22 zeroes - stars in the visible Universe. A recent census of planets said that there could be an Earth-like planet circling 23% of the stars in the night sky.

The maths alone is an almost inconceivable headache of scope, size and scale.

Phone home?

"We should be prepared" for aliens, says professor of space science John Zarnecki, from the Open University. Stephen Hawking says aliens almost certainly exist and senior Seti astronomer Seth Shostak has said that the hunt for alien life should take into account alien "sentient machines", almost disregarding the possibility that there's nothing to search for.

But many scientists argue that because humans have been using wave technology for little over a century - compared to the Earth's age of over four billion years - even if anyone is out there, the window of opportunity to have similar technology is incredibly small.

Indeed, the radio wave as we know it for our communication purposes, is already changing from an analogue wave into a digital pulse, a much more complex signal to detect. And similarly, the waves scientists are looking for may not be the right ones. While a larger amount of the wave spectrum is being examined, it is still a small fraction.

The theory goes that no other inhabited planet is likely to be using the same technology at the same time, or at least within distance of making contact. The actual practicalities of ET phoning home would be, they would argue, basically impossible.

Human history

Another theory is that with intelligence comes destruction. The time between being able to make contact and the self destruction of the species is short.

Purveyors of this theory cite nuclear warfare or the creation of a man-made virus only possible with technological advances as examples of why it is likely.

And many disagree about whether this is anything to look for at all. Indeed, the simplest answer to Fermi's Paradox is that there is no intelligent life to search for so none has been found.

The human race is either an accidental blip in the Universe or we are special and the conditions we evolved in were unique.

The Rare Earth hypothesis argues that because of the intricate design and infrastructure of our planet, the amount of coincidences and circumstances that must occur together make life almost impossible.

Philosophy Professor Nick Bostrom, of Oxford University, has even posed the question whether humans are living in a computer simulation created by beings with a superior intellect. In this model, other beings would not be created within that programme.

But Dr Drake has a more simple answer to why life hasn't been found:

"We just haven't tried enough," he says.

"We've looked carefully at only a few thousand stars and very few channels that are possible on the electromagnetic spectrum and that's hardly even a start.

"If you take reasonable or optimistic values for the [Drake] equation, it suggests that right now, there may be around 10,000 civilisations we can detect in the galaxy.

"That's one in 10,000,000 stars. Before we have a good chance of succeeding, we still have a long way to go."

From the BBC:

California approves first US carbon-trading scheme

California has become the first US state to approve a carbon-trading plan aimed at cutting greenhouse emissions.

State regulators passed a "cap-and-trade" framework to let companies buy and sell permits, giving them an incentive to emit fewer gases.

The aim is to create the second-largest market in the field, after Europe's.

State officials hope the scheme will be copied across the US, but opponents warn it may harm California's growth and lead to higher electricity prices.

The new rules - part of a wider state climate bill passed in 2006 - mean that from 2012 California will allocate licences to pollute and create a market where they can be traded.

A company that emits fewer greenhouse gases than its permits allow, could sell the extra capacity to a dirtier firm.

By making over-polluting more expensive, the scheme aims to provide incentives to develop greener technology.

Over time the total amount of greenhouse gas emissions - the cap - is to be reduced. California wants to cut emissions to 1990 levels by 2020.

However the BBC's Rajesh Mirchandani in Los Angeles says many businesses fear it will add extra costs in an economy struggling to rebound.

Outgoing Governor Arnold Schwarzenegger - who supports environmental causes - argues that growth in the green economy would offset the costs of cap-and-trade.

From the BBC:

US to target fake online pill pedlars

Online stores that sell fake drugs or pills without prescriptions are being targeted by the US government.

It has set up an initiative that will try to shut down the web stores and educate people about the dangers of buying drugs from such places.

Search firms, payment providers and net hosting firms have all pledged to help the crackdown.

Research suggests about 36 million Americans have bought medicines from unlicensed web pharmacies.

"Those who sell prescription drugs online without a valid prescription are operating illegally, undercutting the laws that were put in place to protect patients, and are thereby endangering the public health," said Victoria Espinel, US intellectual property enforcement co-ordinator, in a statement.

"It is a real wake-up call that so many Americans have engaged in this dangerous behaviour," she said.

Web firms joining the initiative include search giant Google, domain registration firm Network Solutions, hosting companies as well as payment processors Paypal, Visa and Mastercard.

Together, the firms hope to tackle every link in the chain that keeps unlicensed pharmacies operating by stopping them showing up in search results, taking their websites offline, delisting the domains they use and stopping payments reaching them.

Many spammers align with online pharmacies and direct those who click on links in junk mail to the pedlars of fake pills.

The commercial partners in the initiative will also share information with law enforcement agencies and fund public awareness campaigns of the dangers of buying drugs from unlicensed pharmacies.

"The abuse of prescription medications is one of the most troubling public health problems in our country today," said Steve Pasierb, president of the non-profit Drugfree.org which runs education campaigns about drug abuse.

Drugfree and the Alliance for Safe Online Pharmacies are planning research to find out why one in six Americans have bought drugs from web pharmacies. They will also look into what they buy and try to uncover the reasons some people see the practice as risky and others do not.

The initiative was announced at a White House summit on intellectual property and is one result of a plan the Obama administration submitted to Congress in mid-2010 that committed to tackling counterfeit medicines.

Woody Woodpecker from space. From the BBC:

Space laser spies for woodpeckers

By Jonathan Amos Science correspondent, BBC News, San Francisco

US scientists are developing techniques to monitor woodpeckers from space.

An Idaho University team has been using a satellite-borne laser to try to predict in which part of a State forest the birds might be living.

The instrument cannot see individual woodpeckers or trees, but it can determine the key characteristics of a woodland, like how dense it is.

Initial work has shown maps built from such data can locate areas favoured by North American pileated woodpeckers.

The scientists want to know where these birds are because they are seen as good indicators of overall bird diversity in a forest.

"They create homes for lots of other species in the forest setting," explained Dr Kerri Vierling from the university's fish and wildlife department.

"They make cavities and those cavities are then used by other species for nesting and roosting.

"Woodpeckers are very sensitive to forest characteristics, and so they're very selective about where they decide to live."

The Idaho research has been presented here in San Francisco at the American Geophysical Union (AGU) Fall Meeting, the world's largest annual gathering of Earth and planetary scientists.

The team assessed some 20,000 hectares of forest in the northern part of the state around Moscow Mountain. They used data acquired by laser altimeters flown on aircraft and on Nasa's Icesat spacecraft before its recent retirement (it was de-orbited in August).

Originally conceived as a means to measure the height of ice surfaces in polar regions, the Icesat instrument has also proved hugely effective in gathering information about vegetation cover in other parts of the globe.

Because the way the beam of light sent down by the laser bounces back off canopy leaves, tree trunks and the ground, it is possible to make general statements about important forest characteristics.

Team-member Patrick Adam told BBC News: "We try to measure the diameter of the trees and their density. We can't do that directly from these instruments, but to get at diameter we can measure the height of the trees because tall trees are fatter than short trees; and we get at the density of the forest by looking at the relative amount of light that is returned from the foliage versus that which is returned from the ground.

"So by looking at the areas that have the tallest trees, we know that they also have the largest trees in diameter, and that there's a better chance of there being woodpeckers there. We don't just hypothesise that, we go out and we actually conduct ground-based woodpecker surveys in these locations as well to verify it."

Dr Lee Vierling from the university's department of forest ecology and biogeosciences added: "There's one species that needs to have high-density forest. That's the pileated woodpecker.

"It's a magnificent bird with a tall red crest on its head. It's a carpenter-ant foraging species so the denser the forest, the better for that particular bird."

Past survey's of forest structure have tended to be fairly labour intensive endeavours, involving sending many people into an area on foot to make the evaluation. And while such assessments produce very detailed results, they are necessarily limited in their spatial information.

Allying remotely sensed data to the ground effort should make habitat surveys more relevant over much broader areas of forest.

"If we are able to predict where woodpeckers are just based on satellite data then we can also surmise, based some other vegetation characteristics, that we might also have higher diversity of forest songbirds or even some mammals and reptiles. That's useful in land management planning and biodiversity planning," said Mr Adam.

"It's a lot easier to use satellite data. It's important to still to do some ground-truthing at a few select points just to make sure we're not totally going off tangent from reality. But in general, yes, we can cover large areas with the airborne lidar, and we're really hopeful with what we can use the space-borne lidar for because that has global coverage, so we could use that at a much larger scale."

The Icesat instrument is no longer in space, but it will be replaced later this decade. In addition, the US space agency is thinking of flying another laser instrument on its Deformation, Ecosystem Structure and Dynamics of Ice (DESDynI) mission.

From the BBC:

Swarm satellite mission to try to sense ocean magnetism

By Jonathan Amos Science correspondent, BBC News, San Francisco

European scientists are going to try to measure the movement of the oceans by tracing their magnetism alone.

The effort will be achieved using three super-sensitive spacecraft called Swarm, which should launch in 2012.

The magnetic signal of the tides sweeping around the globe has been seen before, but the new mission would aim to observe far more detail.

It should provide additional data on how the oceans transfer heat around the Earth, a key feature of the climate.

"When salty ocean water flows through the magnetic field of the Earth, an electric field is generated and this electric field again makes a magnetic field," explained Dr Hermann Lühr, from the German Research Centre for Geosciences (GFZ) and a leading investigator on Swarm.

"We hope to have the possibility to measure the ocean currents which are so important for climate dynamics, because oceans are transporting a lot of heat. The German Champ mission was the first to see at least the tidal signal, but with Swarm we want to be able to monitor the currents themselves."

The new mission is one of the several innovative European Space Agency (Esa) endeavours being discussed this week here at the American Geophysical Union (AGU) Fall Meeting, the largest annual gathering of Earth and planetary scientists.

The major part of Earth's global magnetic field is generated by convection of molten iron within the planet's outer liquid core, but there are other components that contribute to the overall signal, including the magnetism retained in rocks.

Swarm's goal is to investigate all the components, but pulling out the small part produced by ocean movement will probably be its greatest challenge, concedes Dr Mark Drinkwater from Esa's Earth observation division.

"We're talking about tens of thousands of nanoteslas for the total field measured at satellite level, of which one part in 50,000 approximately is contributed by ocean circulation," he told BBC News.

"So it's a akin to finding a needle in a haystack, but the modelling which has shown the retrievability of this element of the magnetic field has demonstrated that it might be possible with [our satellite system]."

It means the spacecraft themselves have to be built with extreme care. The magnetism generated by the satellites' own workings has to be minimised as much as possible, and thoroughly modelled to understand what interference it might be introducing into the scientific data.

Currently under construction with manufacturer EADS Astrium, the satellites look like giant mechanical rats with long tails.

The tails are booms designed to hold Swarm's sensitive magnetometer instruments away from the "noise" that would inevitably come from the electronics inside the main body of the spacecraft.

Every component put on the satellites has had to be tested, right down to the glues that have been used to bond some surfaces together. Any trace ferrous materials in the glues could ruin the measurements.

"You can't go near the spacecraft with a standard spanner or screwdriver - all the tools you would normally use on a spacecraft build. You have to de-gauss them," said platform project manager Andy Jones.

"You have to test them and make sure they're magnetically clean so they'll leave no trace, because if you touch a bolt with a magnetised spanner you will leave a field behind on that bolt."

The Champ spacecraft came out of orbit just a few weeks ago, burning up in the Earth's atmosphere.

Scientists reported first in 2003 that this satellite could sense the subtle magnetic field generated as the waters of the Earth moved under the gravitational tug of the Moon. This signal was apparent because of its very regular pattern.

Sensing the more complex signal from general ocean currents will be much more difficult, however.

At present, researchers use a range of methods to track the currents, including altimetry - the measurement of ocean surface height.

"All these different forms of measurement give you a different answer," said Dr Lühr.

"If you consider altimetry, this relies on seeing how the surface of the water is deformed by the current. But this can also be deformed by other effects like warming up, or having less salt in the water.

"However, if you look into the magnetic field this is just the integral motion from top to bottom of the water, and it will give you a really independent answer about the net transport of that water."

The Swarm satellites will be launched on a single rocket into a polar orbit some 300-500km (186-311 miles) above the Earth.

Two of the satellites will circle the planet in tandem while the plane of the third spacecraft will be offset and gradually diverge over the course of the mission.

This approach is expected to make it much easier for Swarm to separate out all the different components of the global magnetic field.

Scientists say they still have much to learn about Earth's magnetism.

The global field, which shields the planet from high-energy particles emanating from the Sun, appears to be getting weaker, particularly over the South Atlantic where Champ data was used to show there had been a 12% reduction during the course of three decades.

It is in this so-called South Atlantic Anomaly that orbiting spacecraft experience most of their technical failures and where astronauts on the space station receive their largest dose of radiation.

I found this on the BBC website. One of these days, the health professionals will give accurate advice and stick with it rather than say one thing one year, and a different thing a few years later.

New guidance on vitamin D recommends midday sunshine

By Jane Dreaper Health correspondent, BBC News

New health advice recommends short spells in the sun - without suncream and in the middle of the day.

Seven organisations have issued joint advice on vitamin D, which the body gets from natural sunlight.

The nutrient keeps bones strong, and protects against conditions like osteoporosis.

The guidance was drawn up because it is thought fears about skin cancer have made people too cautious about being in the sun.

Cancer Research UK and the National Osteoporosis Society are among the bodies which agree that "little and frequent" spells in summer sunshine several times a week can benefit your health.

The experts now say it is fine to go outside in strong sun in the middle of the day, as long as you cover up or apply sunscreen before your skin goes red.

'Too negative'

Professor Rona Mackie, from the British Association of Dermatologists, said: "Total sun protection with high factor suncream on all the time is not ideal, in terms of vitamin D levels.

"Even Australia has changed its policy on this. They're now producing charts showing parts of Australia where sun protection may not be required during some parts of the year.

"Some of the messages about sun exposure have been too negative. UK summer sunshine isn't desperately strong. We don't have many days in the year when it is very intense.

"What's changed is that we're now saying that exposure of 10 to 15 minutes to the UK summer sun, without suncream, several times a week is probably a safe balance between adequate vitamin D levels and any risk of skin cancer."

Official government advice already recommends vitamin D supplements for pregnant women and children aged under five.

But the experts who wrote the joint statement say mothers often are not made aware of this recommendation. They suggest women consult their GP.

Winter levels of vitamin D can be helped by a break in the tropical sun - or by eating oily fish, liver and fortified margarine.

'Complex area'

Cancer Research UK's chief clinician, Professor Peter Johnson, said: "A good diet and sensible sun exposure will be adequate for the great majority of the UK population to minimise their cancer risk.

"The area of vitamin D and cancer is complex.

"There's some evidence, which is strongest in bowel cancer, that low levels of vitamin D in the blood correlate with the risk of developing cancer.

"But that doesn't mean those low levels cause bowel cancer.

"We think overall that low levels of vitamin D are unlikely to be major contributors to the chances of developing cancer in the UK population."

The joint statement also highlighted questions about vitamin D that warrant further research.

These include finding out the optimal levels of vitamin D, and more detail about the role of dietary sources and supplements.

I wonder if there is a connection between thre retreating polar ice and the bad winter we are having. From the BBC:

Cryosat ice mission returns first science

By Jonathan Amos Science correspondent, BBC News, San Francisco

The Cryosat-2 spacecraft has produced its first major science result.

Radar data from the European satellite has been used to make a map of ocean circulation across the Arctic basin.

Cryosat's primary mission is to measure sea-ice thickness, which has been in sharp decline in recent decades.

But its ability also to map the shape of the sea surface will tell scientists if Arctic currents are changing as a result of winds being allowed to blow more easily on ice-free waters.

"Nobody really knows how the Arctic is going to behave as the ice retreats, but we do anticipate that significant changes will occur," said Dr Seymour Laxon, a Cryosat science team member from University College London, UK.

"This is just the first data, and it shows we now have the tool to monitor what is happening," he told BBC News.

Dr Laxon presented the first Cryosat result in San Francisco at the American Geophysical Union (AGU) Fall Meeting, the world's largest annual gathering of Earth and planetary scientists.

The European Space Agency (Esa) satellite was launched in April.

It carries one of the highest resolution synthetic aperture radars ever put in orbit.

The instrument sends down pulses of microwave energy which bounce off both the top of the Arctic sea-ice and the water in the cracks, or leads, which separate the floes.

By measuring the difference in height between these two surfaces, scientists will be able, using a relatively simple calculation, to work out the overall volume of the marine ice cover in the far north.

But in sensing the surface of the water, Cryosat becomes a powerful tool also to study ocean behaviour.

And the opening months of observations have enabled the Cryosat team to build a unique map from just the radar echoes bouncing off leads.

This map, displayed at the top of the page, describes what researchers call ocean dynamic topography.

It is the height in metres of the water surface above the gravitational level in the Arctic.

Simply put, it shows where water is piled up, and it is water's desire always to "run down hill" that is a major feature underpinning the direction and speed of currents.

"What we've revealed is the first complete picture of ocean dynamic topography in the Arctic Ocean. All missions previously have had large holes in the middle of their Arctic data because of their orbits, even the American Icesat satellite which did a pretty good job of getting dynamic topography - it only went up to 86 degrees North. Cryosat goes up to 88 degrees North."

'Spin up'

In the Northern Hemisphere, ocean currents move clockwise around highs in topography and anti-clockwise around the lows.

Clearly evident therefore in this map (strong red blob) is the Beaufort Gyre, the great clockwise rotation of water that shifts sea-ice around the Arctic.

Also visible are the topographic features related to the Transpolar Drift, which routinely moves sea-ice across the Arctic from the Russian side of the basin; and the East Greenland Current that carries much of the ice that gets exported towards the Atlantic.

The Cryosat team stresses that the map is built from early data and is only a first, static snapshot.

Over the course of the mission, however, this data-set will be improved and provide telling evidence of any changes in Arctic Ocean circulation.

The region has witnessed a dramatic retreat of Arctic sea-ice in summer months, far ahead of what the majority of climate computer models had forecast.

One consequence of the retreat is the potential for open water to "spin up": for the water to start moving faster or in different directions because winds can act on it more easily in the absence of an ice covering.

This could have implications for circulation patterns beyond just the Arctic basin - it could affect sub-Arctic waters, in the Norwegian and Greenland Seas, and ultimately the North Atlantic.

In other words, the climate impacts felt in the Arctic could start feeding back further south.

Model performance

Scientists know also that there is now a lot of warm water at depth in the Arctic.

At present, this deep water's energy is not allowed to influence the sea-ice because of a buffer of colder, less dense water lying between it and the floes above.

But if this warm water were made to well up because of wind-driven changes at the surface, it could have a catastrophic impact on the formation and retention of the ice cover.

Cryosat is intended to provide the information to test all these ideas, and to help improve the performance of computer models that are used to try to forecast future climate behaviour.

"The reason we believe all this is important is because we think from models that a retreat of the ice is going to significantly affect the circulation in the Arctic, and Cryosat is the only tool we've got to measure those changes," said Dr Laxon.

A Christmas item from the BBC:

A new species of tropical mistletoe has been described by scientists at the Royal Botanic Gardens, Kew in London.



The research team found the plant on an expedition to Mount Mabu in northern Mozambique in 2008.



Now, just in time for Christmas, they have confirmed that Helixanthera schizocalyx is new to science.



The plant tops a list of Kew's botanical discoveries of 2010, which includes a Vietnamese orchid and an exceptionally rare tree from Cameroon.

Only four of these giant trees are known to exist

Butterfly specialist, Colin Congdon, spotted the mistletoe in the dense foliage near the summit of Mount Mabu.



He realised that it was different from anything he had seen on the mountains in neighbouring Malawi and Tanzania. Closer inspection back at Kew confirmed it as a new species.



Mistletoes are "hemi-parasitic", meaning they take some of the nutrients they need from other plants.



When birds eat the small fleshy white sweet fruits, the seeds are wiped onto branches of trees, where they stick. Once germinated, the root grows into the living tissue of the tree to "suck out" its nutrients.



Giant genome



Another highlight from this year was the discovery of the largest genome of any living species studied so far. This was found in Paris japonica, a subalpine plant endemic to Honshu, Japan.



Its genome is 50 times the size of the human genome - so large that if this line of genetic code was to be stretched out, it would be taller than the tower of Big Ben.



Plants with such large genomes may be at greater risk of extinction as biologists believe they are less able to adapt to environmental changes.



The other plant discovery highlights from 2010 include:

• Lustrous Vietnamese orchid(Dendrobium daklakense).

The beautiful new orchid may already be endangered

This beautiful orchid, with white and orange flowers, was first collected in 2009 by a local plant hunter in the Dak Lak province of southern Vietnam. Botanists at Kew suspect it is already endangered.

Cameroon canopy giant (Magnistipula multinervia). At 41m, the gigantic but critically endangered tree towers above the canopy of the lush green rainforests of Korup National Park, where it was found. The team used alpine climbing equipment to scale its heights and collect specimens of its fruit from which to identify it. Only four of these trees are known to exist. New palms in Madagascar. Dypsis dracaenoides is one of 14 new palm species found in Madagascar With the help of local palm expert, Joro Rakotoarinivo, Kew scientist John Dransfield has described no fewer than 14 new species of Madagascan palms this year, all of which are threatened in the wild. Among these are Dypsis metallica, which has thick, steely-blue leaves and Dypsis dracaenoides, which resembles a spiky dragon tree. Medicinal aubergine (Solanum phoxocarpum). Commonly known as 'Osigawai' in the local Masai language, the plant was discovered during an expedition to Kenya's Aberdare mountainous cloud forests. It is used medicinally by local people, but Kew scientists say it may be poisonous. Wild Irises from the Andes. The pretty iris could become an ornamental garden plant

Another ocean current maapping story from the BBC:

Goce gravity mission traces ocean circulation

By Jonathan Amos Science correspondent, BBC News, San Francisco

The great sweep of water around Planet Earth has been captured from space in greater detail than ever before.

New observations from Europe's Goce gravity mapping satellite have allowed scientists to plot ocean currents with unprecedented precision.

Understanding gravity is fundamental to being able to track the direction and speed of water across the globe.

The data should improve the climate models which need to represent better how oceans move heat around the planet.

Very strongly represented in the new map is the famous Gulf Stream, the most intense of all the currents where water zips along at velocities greater than one metre per second in places.

"The Gulf Stream takes warm water from the tropics and transports it to higher latitudes, and that warmth is released to the atmosphere and keeps the British Isles, for instance, much warmer than they would otherwise be," said Dr Rory Bingham from Newcastle University, UK.

"When this water has reached higher latitudes, still, because it is by then cold, salty and dense, it will sink; and you get this overturning circulation that helps regulate Earth's climate," he told BBC News.

Dr Bingham presented his ocean circulation data using the latest information from Goce at the recent American Geophysical Union (AGU) Fall Meeting, the largest annual gathering of Earth and planetary scientists.

The European Space Agency (Esa) satellite was launched in March 2009, and is delivering a step change in our vision of how gravity varies across the globe.

Contrary to popular perception, the pull of gravity is not the same everywhere. There are actually very subtle differences in the tug exerted by the mass of the planet from one place to the next.

In the oceans, this has the effect of making water bulge over great submarine mountain ranges and to dip over the deepest ocean trenches.

Goce, which circles the Earth from pole to pole, carries a state of the art gradiometer to sense the variations on a scale better than 100km.

The information is critical to oceanographers attempting to trace the currents.

If they compare the gravity information with measurements of sea surface height made by other spacecraft, they can establish a much better picture of where water is piled up and where it is likely to flow and at what speed.

Very accurate data on currents is already obtained from drifting sensors thrown into the water, but these are necessarily just point measurements.

Oceanographers would hope therefore to combine the truly global perspective they can only get from Goce with the "ground truth" they can retrieve from drifters.

Add in further data collected about sea temperature and it becomes possible to calculate the amount of energy the oceans are moving around Earth's climate system.

Computer models that try to forecast future climate behaviour have to incorporate these details if they are to improve their simulation performance.

"The new information coming from Goce is amazing," said Dr Bingham. "We're getting down to very fine scales now. It's incredible to think for example that we can sense from space very small circulation features like the Mann Eddy, a persistent pocket of water in the Atlantic that just goes around and around."

The ocean circulation information presented at AGU was built using just two months of Goce gravity data.

Scientists expect to construct improved maps when they understand better how the satellite's sophisticated instrument behaves and the observations accumulate.

Goce is not expected to be a long-lived mission. Flying at an altitude of just 255km - the lowest orbit of any research satellite in operation today - it experiences significant drag from the atmosphere.

This has to be counteracted by constantly throttling an ion thruster on the back of the satellite.

When the fuel for the thruster runs out, however, Goce will fall from the sky.

"We have the funding and resources on board to go until at least the end of 2012," said Dr Rune Floberghagen, Esa's Goce mission manager. If European governments then provide additional money and Goce can be frugal with its fuel reserves, the end date could move out to 2014.

Goce is an acronym for Gravity field and steady-state Ocean Circulation Explorer.

It is part of a series of missions that aim to do innovative science in obtaining data on issues of pressing environmental concern.

GOCE SPACECRAFT PROBES GRAVITY FIELD VARIATIONS

• 1. Earth is a slightly flattened sphere - it is ellipsoidal in shape
• 2. Goce senses tiny variations in the pull of gravity over Earth
• 3. The data is used to construct an idealised surface, or geoid
• 4. It traces gravity of equal 'potential'; balls won't roll on its 'slopes'
• 5. It is the shape the oceans would take without winds and currents
• 6. So, comparing sea level and geoid data reveals ocean behaviour
• 7. Gravity changes can betray magma movements under volcanoes
• 8. A precise geoid underpins a universal height system for the world
• 9. Gravity data can also reveal how much mass is lost by ice sheets

Another bee story which was mentioned on the Bee Bee Cee radio news this morning:



Varroa mites live on the bees and weaken their immune systems

Researchers have developed a genetic technique, which could revitalise the fight against the honeybee's worst enemy - the Varroa mite.

The method enables researchers to "switch off" genes in the Varroa mite, a parasite that targets the honeybee.

The scientists say this could eventually be used to force the mites to "self-destruct".

The treatment is now at an early, experimental stage but could be developed into an anti-Varroa medicine.

Varroa destructor is widely accepted to be the major pest affecting the European honeybee, and has been linked to a worldwide decline in these important pollinating insects.

Dr Giles Budge from the National Bee Unit in York, who was involved in the study, said the mites operated a particularly "severe form of parasitism".

The human equivalent, he illustrated, would be having "an organism on your back that's about the size of a dinner plate, which creates a hole through which it can feed and through which its family can feed".

"The hole doesn't seal up - they drink blood through it and inject viruses into it."

To tackle this particularly nasty pest, bee researchers and parasite specialists came together to harness a method called RNA interference (RNAi).

This involves putting a tiny chunk of genetic code into an organism. This code cancels out a specific gene, essentially switching it off.

The researchers added this piece of genetic material to a solution that they soaked the Varroa mites in.

They described in the journal Parasites and Vectors that, via this soaking, their experimental treatment found its way into the mites and switched off the gene they were targeting.

Fool-proof

Dr Alan Bowman from the University of Aberdeen led the research.

He told BBC News that the approach "fooled the immune system of the mite" into attacking itself.

The Varroa mite, which looks like a tiny brown crab is believed to be the biggest global killer of honey bees It was first found in the Asian honeybee population but more recently jumped to the European honeybee The mite injects viruses, suppresses the bees' immune system and feeds on blood Over the past decade, the mite has developed some resistance to chemical controls that beekeepers use If untreated, it can take just 1,000 mites to kill a colony of 50,000 bees.

Dr Budge explained that this proved it was possible to "control gene expression in the mite".

"In the experiment, we've targeted a non-lethal gene, because we were able to monitor if we has successfully silenced it.

"Now, we'll be looking to target genes which, when we silence them, the mite won't be able to function."

In the coming years, the researchers hope to develop this into a medicine, which could be added to the bees' food in order to protect them against Varroa.

"The mites hide in the food that is being provided by the other bees in the colony for honeybee larvae," Dr Budge explained.

"They will hide for several days in that food, so [a beekeeper could] put the treatment into the brood food and the mite, through its normal behaviour, would come into contact with that treatment."

This could solve a conundrum for beekeepers - how to tackle the mites without damaging the bees they live so intimately with.

Currently, beekeepers use chemicals, or mitocides, in carefully controlled doses to control the parasite. They even use trapping methods - physically removing mites from hives.

Dr Bowman said: "This [new method] can target the mite in the hive.

"It would be completely selective - it wouldn't target the bees and wouldn't affect any other pollinating insects, such as ladybirds."

Professor Francis Ratnieks, a bee researcher from the University of Sussex cautioned that it would be a long time before this technique could be applied in the control of Varroa.

"It may be possible to use gene knockout techniques such as RNAi to learn more about the physiology of pests and to use this to develop ways of controlling them, maybe by the development and application of novel pesticides," he said.

"But to do this is a huge undertaking involving [many years] of testing and certification."

The most famous zebra crossing in the world. From the BBC:

Beatles' Abbey Road zebra crossing given listed status

The Abbey Road zebra crossing in north London - made famous after appearing on a Beatles album cover - has been given Grade II listed status.

The crossing - the first of its kind to be listed - is being recognised for its "cultural and historical importance" following advice from English Heritage.

The Beatles were photographed on Abbey Road in Ian Macmillan's iconic cover shot for the 1969 album Abbey Road.

Sir Paul McCartney said it was the "icing on the cake" of a great year.

The original zebra crossing, where the photograph was taken, was moved several metres for traffic management reasons more than 30 years ago, and no original features remain.

'Huge cultural pull'

But John Penrose, Minister for Tourism and Heritage, said: "This London zebra crossing is no castle or cathedral but, thanks to the Beatles and a 10-minute photo-shoot one August morning in 1969, it has just as strong a claim as any to be seen as part of our heritage."

Roger Bowdler, head of designation at English Heritage, said: "This is obviously an unusual case and, although a modest structure, the crossing has international renown and continues to possess huge cultural pull - the temptation to recreate that iconic 1969 album cover remains as strong as ever.

"Together with the nearby Abbey Road studios, also listed at Grade II on our advice, they remain a Mecca for Beatles fans the world over."

Sir Paul said: "It's been a great year for me and a great year for the Beatles and hearing that the Abbey Road crossing is to be preserved is the icing on the cake."

The crossing is outside the Abbey Road studios, where the Beatles recorded much of their output.

That building was granted Grade II listed status in February.

A Grade II listing, the most common protected status, means that a building or monument is recognised as nationally important and of special interest.

I wonder if these elephants remember which species they belong to. From the BBC:

African elephant is two species, researchers say

By Richard Black Environment correspondent, BBC News

Genetic researchers may have resolved a long-standing dispute by proving there are two species of African elephant.

Savannah and forest elephants have been separated for at least three million years, they say, and are as distinct from each other as Asian elephants are from the extinct woolly mammoth.

The researchers also made what they say are the first sequences of nuclear DNA from the extinct American mastodon.

The study is reported in the journal Public Library of Science Biology.

The debate over whether the African elephant is one or two species has been going on for about a decade.

Weighing in at six or seven tonnes, the much larger elephants found on savannah are about twice as heavy as forest-dwellers.

This, along with other differences in size and shape, has led some researchers to conclude there are two species - the savannah (or bush) elephant, Loxodonta africana, and the forest species, Loxodonta cyclotis.

The scientists - from the US, UK and Germany - now say they have proved the case.

"The divergence of the two species took place around the time of the divergence of the Asian elephant and woolly mammoths," said Michi Hofreiter, a specialist in ancient DNA at the UK's York University.

"The split between African savannah and forest elephants is almost as old as the split between humans and chimpanzees. This result amazed us all."

Ancient and modern

The researchers compared sequences of DNA from the nuclei of African and Asian elephants, and from woolly mammoths and the American mastodon.

All are members of the Proboscidea order of mammals.

The mastodon became extinct about 10,000 years ago - around the same time that mammoths disappeared from most of their range.

Although mastodon mitochondrial DNA has been sequenced before, the researchers say they were the first to do the analysis on DNA from the cell nucleus - in this case, using material from a tooth.

"Experimentally, we had a major challenge to extract DNA sequences from two fossils - mammoths and mastodons - and line them up with DNA from modern elephants over hundreds of sections of the genome," said Nadin Rohland of Harvard Medical School.

The genetic "distance" between the Asian elephant and the woolly mammoth turned out to be about the same as between the two African elephant species - which, the researchers say, proves the case for two distinct species in Africa now.

Fragmented world

The picture of elephant conservation across Africa is a mixed one.

In southern countries, the animals are thriving, with populations increasing so fast that governments have had to consider culls.

However, the picture is very different in Central and West Africa, where poaching, ivory smuggling and the bushmeat trade are fragmenting populations.

If there are indeed two species, the forest dwellers are the ones most under pressure, as they tend to be found in areas where poaching and smuggling are rife.

Potentially, confirming the separation could help direct conservation efforts where they are most needed, according to Simon Stuart, chair of the International Union for the Conservation of Nature's Species Survival Commission (SSC).

"We'd have to review the evidence to see whether we need to split the African elephant into two entries on the Red List of Threatened Species," he told BBC News.

"Currently the species is listed as Vulnerable but it's possible that if there are two, one would come out in a more serious category and the other in a less serious one.

"This could be helpful for highlighting the Central African issue."

However, he cautioned, other research groups may well challenge the conclusion of the latest study, and the debate may have some way to run.

On the BBC radio news this morning:

Ancient humans, dubbed 'Denisovans', interbred with us

By Pallab Ghosh Science correspondent, BBC News

Professor Chris Stringer: "It's nothing short of sensational - we didn't know know how ancient people in China related to these other humans"

Scientists say an entirely separate type of human identified from bones in Siberia co-existed and interbred with our own species.

The ancient humans have been dubbed "Denisovans" after the caves in Siberia where their remains were found.

There is also evidence that this population was widespread in Eurasia.

A study in Nature journal shows that Denisovans co-existed with Neanderthals and interbred with our species - perhaps around 50,000 years ago.

An international group of researchers sequenced a complete genome from one of the ancient hominins (human-like creatures), based on nuclear DNA extracted from a finger bone.

'Sensational' find

According to the researchers, this provides confirmation there were at least four distinct types of human in existence when anatomically modern humans (Homo sapiens sapiens) first left their African homeland.

Along with modern humans, scientists knew about the Neanderthals and a dwarf human species found on the Indonesian island of Flores nicknamed "The Hobbit". To this list, experts must now add the Denisovans.

The implications of the finding have been described by Professor Chris Stringer of the Natural History Museum in London as "nothing short of sensational".

Scientists were able to analyse DNA from a tooth and from a finger bone excavated in the Denisova cave in southern Siberia. The individuals belong to a genetically distinct group of humans that were distantly related to Neanderthals but even more distantly related to us.

The finding adds weight to the theory that a different kind of human could have existed in Eurasia at the same time as our species.

Researchers have had enigmatic fossil evidence to support this view but now they have some firm evidence from the genetic study carried out by Professor Svante Paabo of the Max Planck Institute in Leipzig, Germany.

"A species of early human living in Europe evolved," according to Professor Paabo.

"There was a western form that was the Neanderthal and an eastern form, the Denisovans."

The study shows that Denisovans interbred with the ancestors of the present day people of the Melanesian region north and north-east of Australia. Melanesian DNA comprises between 4% and 6% Denisovan DNA.

David Reich from the Harvard Medical School, who worked with Svante Paabo on the study, says that the fact that Denisovan genes ended up so far south suggests they were widespread across Eurasia: "These populations must have been spread across thousands and thousands of miles," he told BBC News.

One mystery is why the Denisovan genes are unique in modern Melanesians and are not found in other Eurasian groups that have so far been sampled.

'Fleeting encounter'

Professor Stringer believes it is because there may have been only a fleeting encounter as modern humans migrated through South-East Asia and then on to Melanesia.

"It could be just 50 Denisovans interbreeding with a thousand modern humans. That would be enough to produce this 5% of those archaic genes being transferred," he said.

"So the impact is there but the number of interbreeding events might have been quite small and quite rare."

No one knows when or how these humans disappeared but, according to Professor Paabo, it is very likely something to do with modern people because all the "archaic" humans, like Denisovans and Neanderthals disappeared sometime after Homo sapiens sapiens appeared on the scene.

"It is fascinating to see direct evidence that these archaic species did exist (alongside us) and it's only for the last few tens of thousands of years that is unique in our history that we are alone on this planet and we have no close relatives with us anymore," he said.

The study follows a paper published earlier this year by Professor Paabo and colleagues that showed there was interbreeding between modern humans and Neanderthals as they emerged from Africa 60,000 years ago.

Cheetah, cheetah, burning bright, in the deserts late at night. From the BBC:

One of the world's most elusive cats has been photographed by a night time camera trap, after a year-long search for the animal.

The ghostly image of the Saharan cheetah has excited conservationists, as perhaps fewer than 10 of the cats survive in the deserts of Termit, Niger, where the photograph was taken.

Almost nothing is known of the Saharan cheetah, except that it endures extremely high temperatures and appears to survive without a permanent source of water.

On one journey recently, a cheetah eluded researchers, using the desert geography to maintain its enigmatic, elusive reputation Thomas Rabeil Saharan Conservation Fund

Scientists working for the Saharan Conservation Fund (SCF) took the image as part of the Saharan Carnivore Project, an effort launched in conjunction with the University of Oxford, UK, four years ago to research and document larger predators roaming one of the world's most inhospitable habitats.

SCF researchers, led by John Newby and Tim Wacher, focused their attention on the Niger's Termit Massif and the neighbouring Tin Toumma desert

These areas have become the most important remaining refuges for wildlife in the entire Sahara.

Although conservationists have been working in or around the massif since 2000, they have only observed cheetahs there three times, and the cat has not been photographed.

That was until a camera trap, set by SCF researchers, captured an eerie image of a Saharan cheetah passing by at night.

"The cheetahs of Termit Massif are extremely shy, rarely revealing themselves to researchers and few visitors go there," the SCF's Thomas Rabeil told the BBC.

DESERT 'GHOSTS' See more 'ghostly' photographs of extremely elusive wild cat and dog species photographed by the Saharan Carnivore Project

Saharan cheetahs remain an enigma, even to scientists who specialise in studying rare cats.

For example is it not yet known if Saharan cheetahs are more closely related to other cheetahs in Africa, or those living in Iran, which make up the last remaining wild population of Asiatic cheetahs.

Saharan cheetahs appear to have different colour and spot patterns compared to common cheetahs that roam elsewhere in Africa.

However, "very little is known about the behavioural differences between the two cheetahs, as they have never been studied in the wild," says Dr Rabeil.

"From observations of tracks and anecdotal reports they seem to be highly adaptable and able to eke out an existence in the Termit and Tin Toumma desert."

Experts believe the Saharan cheetah has found a way to survive in a habitat where there is no permanent source of water.

In doing so the animals endure exceptionally high summer temperatures.

CHEETAH FACTS Watch stunning footage of an epic cheetah hunt, as three cats attempt to take down an ostrich Watch more videos of cheetah behaviour at BBC Wildlife Finder Find out how animals survive in extreme desert environments

Attempts to track Saharan cheetahs also suggest that the cats roam considerable distances in a bid to hunt prey, which might include addax, dama and dorca gazelles or Barbary sheep.

That makes finding and following the cats almost impossible.

"Project personnel have gone to extraordinary lengths to try and observe these animals directly, resorting to extended surveys on camel-back," Dr Rabeil told the BBC.

"On one such eight-day journey recently a cheetah eluded researchers, leaving clearly identifiable tracks behind but changing direction and using the desert geography to maintain its enigmatic, elusive reputation," he said.

Saharan cheetahs are thought to range in six countries: Algeria, Togo, Niger, Mali, Benin, and Burkina Faso.

But the total population may be fewer than 250 mature individuals.

The first ever camera trap photograph of one was only taken last year in Algeria.

More than 50 cheetahs are thought to live there, compared to 10 or fewer in Niger.

A very Happy Christmas to you all

And a seasonal article from the BBC:

The printed future of Christmas dinner

By Lakshmi Sandhana Technology reporter

Christmas dinner traditionally centres on the turkey or goose. But if US scientists have their way, everyone may be sitting around a printer.

The team at Cornell University's Computational Synthesis Lab (CCSL) are building a 3D food printer, as part of the bigger Fab@home project, which they hope one day will be as commonplace as the microwave oven or blender.

Just pop the raw food "inks" in the top, load the recipe - or 'FabApp' - and the machine would do the rest.

"FabApps would allow you to tweak your foods taste, texture and other properties," says Dr Jeffrey Ian Lipton, who leads the project.

"Maybe you really love biscuits, but want them extra flaky. You would change the slider and the recipe and the instructions would adjust accordingly."

The goal is to blow the lid off cooking as we know it and change the future of food production.

People lacking even basic culinary skills could download the recipe files of master chefs or print out nutrition-packed dishes recommended by their doctors.

Chefs could also create new foodstuffs and customizable menus for fussy customers.

And it would have the added benefit of cutting out some of the waste of current food production methods, says Homaro Cantu, chef and owner of the Moto Restaurant in Chicago, Illinois, who has printed sushi using an ink jet printer.

"Imagine being able to essentially 'grow', 'cook' or prepare foods without the negative industrial impact - everything from fertilizers to saute pans and even packaging," he says.

"The production chain requirements for food would nearly be eliminated."

Local food, could really mean local.

"You can imagine a 3D printer making homemade apple pie without the need for farming the apples, fertilizing, transporting, refrigerating, packaging, fabricating, cooking, serving and the need for all of the materials in these processes like cars, trucks, pans, coolers, etc," he adds.

'Designer domes'

While other researchers have toyed with the idea of printing food - notably at the Massachusetts Institute of Technology - the Fab@home team is actively working on creating an affordable syringe-based 3D printer that can print a wide variety of foods.

The current design is basically a series of precise syringes that deposits food inks line by line, and layer by layer, according to an electronic blueprint.

 

The blueprint specifies exactly what materials go where and are currently drawn up using traditional engineering computer aided design (CAD) software.

"In the future there would probably be a kind of 'ChefCAD' that will allow people to design their own food constructions," said Professor Hod Lipson, Director of CCSL.

"You'd hit the print button and it would ask you how many copies," said Prof Lipson.

The raw materials used to print the food are currently limited to anything that can be extruded from a syringe. Commonly they are liquid or melted versions of ingredients, including chocolate, cookie dough, cheese, or cake batter.

However, the team are now experimenting with mixing foods with hydrocolloids - substances that form gels with water, generally used to thicken food products - to create a range of basic liquid ingredients.

They also recognize that people will want to create their own inks, allowing everyone to become Willy Wonka.

This creates its own problems.

"Each material will behave differently," says Dr Lipton.

The solution would be to create a machine that constantly examines what it is printing, tweaking the design and mixture of raw ingredients as it goes.

"I feel like both approaches will be used going forward," he says. "In situations where you want complete control over the food intact and properties - hospitals, space flight, personal dieting - people will use the hydrocolloids approach.

When doing home cooking you want to be able to use your own hand-made ingredients and feedback will be the only solution."

The team has already had some success with their prototypes, creating cookies with embedded letters and designer domes made of turkey meat.

They hope to make their designs and ingredients list more complex, and able to handle food that people want to eat.

"Imagine if the microwave oven worked only with frozen pre cooked hot dogs when it first came out - no one would have them now," says Dr Lipton.

Long-term, the team believes that people will take to the technology by creating their own 3D printable food recipe social networks with everyone improving on each other's creations.

"3D printing will do for food what e-mail and instant messaging did for communication," says Mr Cantu.

"What if you could have mom's homemade apple pie sent via e-mail and printed up at home? Her apple pie becomes as close as an instant message on Facebook."

Merry Christmas Loro

Thank you muf

From the BBC:

From the BBC:

New solar fuel machine 'mimics plant life'

By Neil Bowdler Science reporter, BBC News

A prototype solar device has been unveiled which mimics plant life, turning the Sun's energy into fuel.

The machine uses the Sun's rays and a metal oxide called ceria to break down carbon dioxide or water into fuels which can be stored and transported.

Conventional photovoltaic panels must use the electricity they generate in situ, and cannot deliver power at night.

Details are published in the journal Science.

The prototype, which was devised by researchers in the US and Switzerland, uses a quartz window and cavity to concentrate sunlight into a cylinder lined with cerium oxide, also known as ceria.

Ceria has a natural propensity to exhale oxygen as it heats up and inhale it as it cools down.

If as in the prototype, carbon dioxide and/or water are pumped into the vessel, the ceria will rapidly strip the oxygen from them as it cools, creating hydrogen and/or carbon monoxide.

Hydrogen produced could be used to fuel hydrogen fuel cells in cars, for example, while a combination of hydrogen and carbon monoxide can be used to create "syngas" for fuel.

It is this harnessing of ceria's properties in the solar reactor which represents the major breakthrough, say the inventors of the device. They also say the metal is readily available, being the most abundant of the "rare-earth" metals.

Methane can be produced using the same machine, they say.

Refinements needed

The prototype is grossly inefficient, the fuel created harnessing only between 0.7% and 0.8% of the solar energy taken into the vessel.

Most of the energy is lost through heat loss through the reactor's wall or through the re-radiation of sunlight back through the device's aperture.

But the researchers are confident that efficiency rates of up to 19% can be achieved through better insulation and smaller apertures. Such efficiency rates, they say, could make for a viable commercial device.

"The chemistry of the material is really well suited to this process," says Professor Sossina Haile of the California Institute of Technology (Caltech). "This is the first demonstration of doing the full shebang, running it under (light) photons in a reactor."

She says the reactor could be used to create transportation fuels or be adopted in large-scale energy plants, where solar-sourced power could be available throughout the day and night.

However, she admits the fate of this and other devices in development is tied to whether states adopt a low-carbon policy.

"It's very much tied to policy. If we had a carbon policy, something like this would move forward a lot more quickly," she told the BBC.

It has been suggested that the device mimics plants, which also use carbon dioxide, water and sunlight to create energy as part of the process of photosynthesis. But Professor Haile thinks the analogy is over-simplistic.

"Yes, the reactor takes in sunlight, we take in carbon dioxide and water and we produce a chemical compound, so in the most generic sense there are these similarities, but I think that's pretty much where the analogy ends."

Daniel Davies, chief technology officer at the British photovoltaic company Solar Century, said the research was "very exciting".

"I guess the question is where you locate it - would you put your solar collector on a roof or would it be better off as a big industrial concern in the Sahara and then shipping the liquid fuel?" he said.

Solar technology is moving forward apace but the overriding challenges remain ones of efficiency, economy and storage.

New-generation "solar tower" plants have been built in Spain and the United States which use an array of mirrors to concentrate sunlight onto tower-mounted receivers which drive steam turbines.

A new Spanish project will use molten salts to store heat from the Sun for up to 15 hours, so that the plant could potentially operate through the night.

One of the more unusual stories from the BBC:

Ancient rock art's colours come from microbes

A particular type of ancient rock art in Western Australia maintains its vivid colours because it is alive, researchers have found.

While some rock art fades in hundreds of years, the "Bradshaw art" remains colourful after at least 40,000 years.

Jack Pettigrew of the University of Queensland in Australia has shown that the paintings have been colonised by colourful bacteria and fungi.

These "biofilms" may explain previous difficulties in dating such rock art.

Professor Pettigrew and his colleagues studied 80 of these Bradshaw rock artworks - named for the 19th-Century naturalist who first identified them - in 16 locations within Western Australia's Kimberley region.

They concentrated on two of the oldest known styles of Bradshaw art - Tassel and Sash - and found that a vast majority of them showed signs of life, but no paint.

The team dubbed the phenomenon "Living pigments".

"'Living pigments' is a metaphorical device to refer to the fact that the pigments of the original paint have been replaced by pigmented micro-organisms," Professor Pettigrew told BBC News.

"These organisms are alive and could have replenished themselves over endless millennia to explain the freshness of the paintings' appearance."

Among the most frequent inhabitants of the boundaries of the artwork was a black fungus, thought to be of the group of fungi known as Chaetothyriales.

Successive generations of these fungi grow by cannibalising their predecessors. That means that if the initial paint layer - from tens of thousands of years ago - had spores of the fungus within it, the current fungal inhabitants may be direct descendants.

The team also noted that the original paint may have had nutrients in it that "kick-started" a mutual relationship between the black fungi and red bacteria that often appear together. The fungi can provide water to the bacteria, while the bacteria provide carbohydrates to the fungi.

The exact species involved in these colourations have yet to be identified, and Professor Pettigrew said that the harsh conditions in the Kimberley region may hamper future research.

However, even the suggestion of these "living pigments" may explain why attempts to date some rock art has shown inconsistent results: although the paintings may be ancient, the life that fills their outlines is quite recent.

"Dating individual Bradshaw art is crucial to any further understanding of its meaning and development," Professor Pettigrew said.

"That possibility is presently far away, but the biofilm offers a possible avenue using DNA sequence evolution. We have begun work on that but this will be a long project."

From the BBC:

Neanderthals cooked and ate vegetables

By Pallab Ghosh Science correspondent, BBC News

Neanderthals cooked and ate plants and vegetables, a new study of Neanderthal remains reveals.

Researchers in the US have found grains of cooked plant material in their teeth.

The study is the first to confirm that the Neanderthal diet was not confined to meat and was more sophisticated than previously thought.

The research has been published in the Proceedings of the National Academy of Sciences.

The popular image of Neanderthals as great meat eaters is one that has up until now been backed by some circumstantial evidence. Chemical analysis of their bones suggested they ate little or no vegetables.

This perceived reliance on meat had been put forward by some as one of the reasons these humans become extinct as large animals such as mammoths declined due to an Ice Age.

But a new analysis of Neanderthal remains from across the world has found direct evidence that contradicts the chemical studies. Researchers found fossilised grains of vegetable material in their teeth and some of it was cooked.

Although pollen grains have been found before on Neanderthal sites and some in hearths, it is only now there is clear evidence that plant food was actually eaten by these people.

Professor Alison Brooks, from George Washington University, told BBC News: "We have found pollen grains in Neanderthal sites before but you never know whether they were eating the plant or sleeping on them or what.

"But here we have a case where a little bit of the plant is in the mouth so we know that the Neanderthals were consuming the food."

More like us

One question raised by the study is why the chemical studies on Neanderthal bones have been wide of the mark. According to Professor Brooks, the tests were measuring proteins levels, which the researchers assumed came from meat.

"We've tended to assume that if you have a very high value for protein in the diet that must come from meat. But... it's possible that some of the protein in their diet was coming from plants," she said.

This study is the latest to suggest that, far from being brutish savages, Neanderthals were more like us than we previously thought.

This must be the most ambitious computer project to date. From the BBC:

Earth project aims to 'simulate everything'

By Gareth Morgan Technology reporter

It could be one of the most ambitious computer projects ever conceived.

An international group of scientists are aiming to create a simulator that can replicate everything happening on Earth - from global weather patterns and the spread of diseases to international financial transactions or congestion on Milton Keynes' roads.

Nicknamed the Living Earth Simulator (LES), the project aims to advance the scientific understanding of what is taking place on the planet, encapsulating the human actions that shape societies and the environmental forces that define the physical world.

"Many problems we have today - including social and economic instabilities, wars, disease spreading - are related to human behaviour, but there is apparently a serious lack of understanding regarding how society and the economy work," says Dr Helbing, of the Swiss Federal Institute of Technology, who chairs the FuturICT project which aims to create the simulator.

Knowledge collider

Thanks to projects such as the Large Hadron Collider, the particle accelerator built by Cern, scientists know more about the early universe than they do about our own planet, claims Dr Helbing.

What is needed is a knowledge accelerator, to collide different branches of knowledge, he says.

"Revealing the hidden laws and processes underlying societies constitutes the most pressing scientific grand challenge of our century."

The result would be the LES. It would be able to predict the spread of infectious diseases, such as Swine Flu, identify methods for tackling climate change or even spot the inklings of an impending financial crisis, he says.

But how would such colossal system work?

For a start it would need to be populated by data - lots of it - covering the entire gamut of activity on the planet, says Dr Helbing.

It would also be powered by an assembly of yet-to-be-built supercomputers capable of carrying out number-crunching on a mammoth scale.

Although the hardware has not yet been built, much of the data is already being generated, he says.

For example, the Planetary Skin project, led by US space agency Nasa, will see the creation of a vast sensor network collecting climate data from air, land, sea and space.

In addition, Dr Helbing and his team have already identified more than 70 online data sources they believe can be used including Wikipedia, Google Maps and the UK government's data repository Data.gov.uk.

Drowning in data

Integrating such real-time data feeds with millions of other sources of data - from financial markets and medical records to social media - would ultimately power the simulator, says Dr Helbing.

The next step is create a framework to turn that morass of data in to models that accurately replicate what is taken place on Earth today.

That will only be possible by bringing together social scientists and computer scientists and engineers to establish the rules that will define how the LES operates.

Such work cannot be left to traditional social science researchers, where typically years of work produces limited volumes of data, argues Dr Helbing.

Nor is it something that could have been achieved before - the technology needed to run the LES will only become available in the coming decade, he adds.

Human behaviour

For example, while the LES will need to be able to assimilate vast oceans of data it will simultaneously have to understand what that data means.

That becomes possible as so-called semantic web technologies mature, says Dr Helbing.

Today, a database chock-full of air pollution data would look much the same to a computer as a database of global banking transactions - essentially just a lot of numbers.

But semantic web technology will encode a description of data alongside the data itself, enabling computers to understand the data in context.

What's more, our approach to aggregating data stresses the need to strip out any of that information that relates directly to an individual, says Dr Helbing.

That will enable the LES to incorporate vast amounts of data relating to human activity, without compromising people's privacy, he argues.

Once an approach to carrying out large-scale social and economic data is agreed upon, it will be necessary to build supercomputer centres needed to crunch that data and produce the simulation of the Earth, says Dr Helbing.

Generating the computational power to deal with the amount of data needed to populate the LES represents a significant challenge, but it's far from being a showstopper.

If you look at the data-processing capacity of Google, it's clear that the LES won't be held back by processing capacity, says Pete Warden, founder of the OpenHeatMap project and a specialist on data analysis.

While Google is somewhat secretive about the amount of data it can process, in May 2010 it was believed to use in the region of 39,000 servers to process an exabyte of data per month - that's enough data to fill 2 billion CDs every month.

Reality mining

If you accept that only a fraction of the "several hundred exabytes of data being produced worldwide every year… would be useful for a world simulation, the bottleneck won't be the processing capacity," says Mr Warden.

"Getting access to the data will be much more of a challenge, as will figuring out something useful to do with it," he adds.

Simply having lots of data isn't enough to build a credible simulation of the planet, argues Warden. "Economics and sociology have consistently failed to produce theories with strong predictive powers over the last century, despite lots of data gathering. I'm sceptical that larger data sets will mark a big change," he says.

"It's not that we don't know enough about a lot of the problems the world faces, from climate change to extreme poverty, it's that we don't take any action on the information we do have," he argues.

Regardless of the challenges the project faces, the greater danger is not attempting to use the computer tools we have now - and will have in future - to improve our understanding of global socio-economic trends, says Dr Helbing.

"Over the past years, it has for example become obvious that we need better indicators than the gross national product to judge societal development and well-being," he argues.

At it's heart, the LES is about working towards better methods to measure the state of society, he says, which would account for health, education and environmental issues. "And last but not least, happiness."

I missed this story posted by the BBC just before Christmas:

Scientists produce 'world's smallest Christmas card'

Scientists have produced what they believe is the world's smallest Christmas card.

It was created by nantotechnologists at the University of Glasgow and is so small it could fit on to the surface of a postage stamp 8,276 times.

The image, which measures 200x290 micro-metres, features a Christmas tree and is etched on a tiny piece of glass.

The team behind the project said the technology could eventually be used in products such as TVs and cameras.

The university's school of engineering drew up the design to highlight its "world-leading" nanotechnology expertise.

Prof David Cumming said: "Our nanotechnology is among the best in the world but sometimes explaining to the public what the technology is capable of can be a bit tricky.

"We decided that producing this Christmas card was a simple way to show just how accurate our technology is.

"The process to manufacture the card only took 30 minutes. It was very straightforward to produce as the process is highly repeatable - the design of the card took far longer than the production.

Human hair

Prof Cumming added: "The card is 200 micro-metres wide by 290 micro-metres tall.

"To put that into some sort of perspective, a micro-metre is a millionth of a metre; the width of a human hair is about 100 micro-metres.

"You could fit over half a million of them on to a standard A5 Christmas card - but signing them would prove to be a bit of a challenge."

The colours were produced by a process known as plasmon resonance in a patterned aluminium film made in the university's James Watt Nanofabrication Centre.

Although the Christmas card example is a simple demonstration, the university said the underlying technology had important real-world applications.

The electronics industry is taking advantage of micro and nano-fabrication technology by using it in bio-technology sensing, optical filtering and light control components.

The applications are critical in the future development of the digital economy and could eventually find their way into cameras, television and computer screens to reduce the manufacturing cost.

From the BBC:

All change: Theories of human ancestry get an overhaul

By Professor Clive Finlayson Director, Gibraltar Museum

For over 150 years the name "Neanderthal" has been household property.

And it has become associated with dim-witted, ape-like brutes that scurried across vast ice-covered wastes waiting for the day when our ancestors - the intelligent and modern humans - would wipe them from the face of the Earth.

Now, we have discovered the Denisovans and I wonder what image we will choose to give them.

But there are already hints that suggest that the status quo will prevail and we will find reasons for making these people a little bit less clever than our direct ancestors.

The irony is that the scientific community is going to have to come round to the acceptance that the Denisovans and the Neanderthals also belonged to the species which we call Homo sapiens.

The Denisovans, for that is how we must know them (for now as the authors of a recent paper in Nature have preferred not to give them a scientific name), lived in southern Siberia.

We do not know how much further their range extended but it seems highly unlikely that they were confined to this region alone.

The site in which their remains were found seems to have been occupied over two periods, one older than 50,000 years ago and the other between 30,000 and 23,000 years ago.

It seems that it is not possible at this stage to determine whether the Denisovans occupied the site in one or other period, or both. Either way they must have lived close to Neanderthals or our own ancestors, depending on which time period they lived in.

An earlier study already showed that Neanderthals contributed a percentage of their genome to some of us, right across Eurasia from the west to the extreme south-east.

The present study shows that the Denisovans were closer genetically to the Neanderthals than to us but that we all shared a remote common ancestor.

Reality check

The Denisovans do not seem to have contributed much to the European gene pool but their genes made it all the way into that of the Melanesians.

Put together, this evidence shows us that humans formed an interwoven network of populations with varying degrees of gene flow between them. Some humans may have looked quite different from each other, revealing a combination of adaptation to local environments and genetic drift, but it does seem as though those differences were not large enough to prevent genetic interchange.

I have suggested that humans, at any point in time in our evolutionary history, behaved as a polytypic species; they consisted of an array of regional populations clustered into geographical races which had not achieved independent species status - they could exchange genes when they met.

And this is not a new idea either. The great evolutionary biologist Ernst Mayr proposed it for the human species as far back as 1950! An obsession with turning each new fossil into a distinct species has clouded the biological reality that we are now retrieving.

One aspect of the findings of this recent study shows that the Neanderthals experienced a severe genetic bottleneck in the course of their history which means that their overall genetic diversity was much lower than that of present-day humans.

The Denisovans seem to have escaped the bottleneck too. Now, the interesting point for me is that the bottleneck, affecting all Neanderthals, was an ancient one.

It predated the arrival of modern humans into Eurasia and thus must have been the result of an ecological impact and not competition.

This conclusion is exactly what I have been predicting over the past decade, that Neanderthal populations were in decline for a long time and well before the arrival of modern humans.

Food for thought

Almost concurrently with the Denisova findings, a paper published in the US Proceedings of the National Academy of Sciences (PNAS) journal looked at an unusual case - a family group of Neanderthals who lived in northern Spain and whose remains were preserved.

These Neanderthals from El Sidrón have provided DNA that reveals that the males were very similar to each other but the females were not. The conclusion is that Neanderthals were patrilocal - the males stayed put while the females wandered between clans and tribes.

What is more, these Neanderthals lived in small groups with low genetic diversity. Added to the Denisova paper findings, we can begin to understand the population biology of the Neanderthals. As I have suggested previously, their populations became heavily fragmented and gene flow between them became reduced.

They were in crisis but not because of the arrival of modern humans. Like pandas today they were in danger of extinction.

They were not in such danger because they were ape-like brutes either. A paper published this week in the Proceedings of the National Academy of Sciences has provided conclusive evidence that Neanderthals regularly ate plants and even cooked them before eating them!

A detailed study of Neanderthal teeth from Spy in Belgium and Shanidar in Iraq found traces of plant matter including grass seed starches that had been cooked. We had suspected that Neanderthals consumed plants for some time, and it was logical to do so, but now we have the evidence.

So those who claimed that Neanderthals only ate meat, an almost physiological impossibility, have to rethink their argument.

Seafood platter

In 2008, we published evidence of marine mammal and mollusc consumption by Neanderthals in Gorham's Cave, also in the PNAS journal. I have been arguing that omnivory is a defining characteristic of the genus Homo, including the Neanderthals, and these latest findings have confirmed this conclusion.

So the Neanderthals weren't stupid apes but humans, and they interbred with our own ancestors. Yet they were affected by environmental perturbation and went extinct.

This is a lesson for us all to learn. But in spite of the evidence there are those who will resist. A hallmark, for the archaeologists, of modern humanity has been the Upper Palaeolithic technology.

In recent years the boundary between this technology and its makers has become increasingly diffuse and I would argue that technology can no longer be used as proxy for human taxa.

Now, the findings at Denisova have included typically Upper Palaeolithic technology. It would be ironic if we were to establish that it was the Denisovans, not modern humans, who had made them.

But the authors of the Denisova paper are unsure of the association between the bones and the tools and have opted for "the reasonable hypothesis that the phalanx and molar belong to the older occupation".

In other words the Denisovans lived prior to 50,000 years ago and the tools were made between 30,000 and 23,000 years ago by invisible humans.

A Happy New Year to everyone

On the BBC radio news yesterday:

Scientists have found a colony of rare Mediterranean monk seals at an undisclosed location in Greece.

The species is the world's most endangered seal, and one of the most endangered marine mammals - fewer than 600 individuals remain.

Researchers are keeping the location of the colony secret to avoid having the seals disturbed by human visitors.

It is the only place in the region where seals lie on open beaches, rather than hide in coastal caves.

Alexandros Karamanlidis, scientific co-ordinator of the Mom/Hellenic Society for the Study and Protection of the Monk seal, explained that this was the seals' "original behaviour".

We're trying to make this a place where the seals feel secure Alexandros Karamanlidis Mom/Hellenic Society for the Study and Protection of the Monk Seal In pictures: A rare haven for endangered seals

"It is human disturbance that has caused the species to retreat to inaccessible caves," he told BBC News.

"So this place is incredibly important - the seals feel so secure that they go out on to open beaches."

The Mom researchers, whose society name is derived from the Latin name of the species, Monachus monachus, have been monitoring and studying monk seals for more than 20 years.

This has not been an easy task when most of the animals now live in areas that are not visible from the water line.

By driving the seals into secluded caves, the scientists say, human activity has also affected the number of seal pups that survive into adulthood.

The researchers have placed cameras on the island to study the seals

Dr Karamanlidis explained: "Because of human disturbance, [the seals] give birth in these coastal caves, [meaning that] more pups die during storms."

The number of seal pups born annually in the newly discovered colony on this tiny island is amongst the highest recorded anywhere in the Mediterranean Sea.

The team has placed cameras on the island to study the seals remotely.

The area's popularity with tourists has gradually driven the animals away from other beaches, and the scientists hope to stop the same thing happening on this island.

"It's a small island in the Aegean with nice sandy beaches," Dr Karamanlidis told BBC News.

"So if it remains open to people, the place will get crowded and the seals will start going away again."

More than half of the world's remaining monk seals live in Greece.

The society is now appealing to the Greek government to make the part of the island where the seals live, and its inshore waters, a marine protected area.

"The seals only survive in Greece because we have these isolated islands that people do not have access to," said Dr Karamanlidis.

"So we're trying to make this a place where the seals feel secure."

From the BBC:

Simple rubber device mimics complex bird-song

By Mark Kinver Science and environment reporter, BBC News

A simple rubber device that replicates complex bird songs has been developed by a team of US researchers.

The song is produced by blowing air through the device, which mimics a bird's vocal tract, the team explained.

The findings appear to challenge the idea that birds had to learn complicated neurological controls in order to produce distinctive calls.

The team plans to share its data with biologists to see if it sheds new light on how birds produce complex songs.

"I definitely did not think that I would be able to produce a whole bird song when we started," explained Aryesh Mukherjee, a member of the project team from Harvard University.

"We were just playing around and I probed the device in a certain way and it started playing a bird song - that was very exciting."

He added that the design of the device was very rudimentary: "It is made out of two pieces of rubber, which are stuck together but leaving a little area in the middle that forms the 'vocal tract'."

As well as the air source, the device is pressed together by a motor that replicates the action of a contracting muscle.

"In the terms of physics, the tract is just an elastic membrane of springs. If you tense it correctly, and probe it in a certain way, it starts vibrating," Mr Mukherjee told BBC News.

"Our project was to control the frequency of those vibrations."

The team were able to replicate a number of bird-songs, such as Bengalese finches and vireos, and were able to closely model the song of zebra finches.

"Making it sound like a zebra finch is the holy grail of the project," Mr Mukherjee said.

"We have been able to come pretty close to it, but we have been able to replicate other bird species much better."

He suggested that the song of the zebra finch was a little bit more complex, therefore it required a little fine tuning.

"But we are getting close," he added.

Good vibrations

The team's discovery was made during a project to learn more about the physical behaviour of vocal tracts.

"We were working with neuroscientists who were trying to understand how a bird learns to sing.

"It was considered a very complicated process, and we tried to uncover some of the mysteries with physics."

Bird-song, a complex sound full of intricate patterns and rich harmonies, has been the subject of many studies. Neuroscientists, over the years, have provided insights into how young birds learn their songs from adult birds, requiring a series of complex neurological changes in order for them to control their voices.

But Mr Mukherjee said the project's results showed that it was possible to replicate bird-song without high degrees of control inputs.

"By just having one muscle (motor pressing the device) in the equation, you can get a lot of sounds," he explained.

"Translating that back into the idea of neurological control... it suggests that the control needed to produce seemingly complex songs is not as challenging as previously thought."

However, Mr Mukherjee said that whether this challenges current thinking on how birds produce their song was outside their area of expertise.

"We are in no position to make a claim about what this has to do with bio-physics or neurological control within birds. All we can say is what we have learned from our experiments, and share that information with biologists.

Another member of the team Shreyas Madre - now an assistant professor at Brown University, Rhode Island - is developing a mathematical model to see if it is possible to identify some of the key principles in producing complex birdsong.

The team plans to publish its findings in a paper in the near future.

From the BBC:

Sabretooth cats threatened most ancient human ancestor

By Paul Rincon Science reporter, BBC News

Humankind's oldest known ancestor probably lived in fear of several large sabretooth cats that roamed the same ancient lakeside habitat in Africa.

Palaeontologists have identified two new sabretooth species among fossils unearthed at Toros Menalla in Chad.

In 2001, a team unearthed remains of a seven million-year-old human-like creature - or hominid - known as "Toumai" at the central African site.

Its discoverers argue that Toumai is the oldest hominid known to science.

The fossilised skull of Toumai (which means "hope of life" in the local Dazaga language of Chad) was found in the Djurab desert by a team led by Michael Brunet of the University of Poitiers, France.

The position of a hole at the bottom of the skull called the foramen magnum suggests that Toumai (Sahelanthropus tchadensis) walked upright - an important signature of the human lineage.

The brainstem enters and exits the skull through this hole; in great apes, it is positioned more towards the back of the skull. But in hominids - including Toumai - it is placed more towards the front of the skull.

The ancient fossil caused a worldwide sensation when it was unveiled in the pages of Nature journal in 2002.

However, the interpretation of Toumai as a human relative is controversial. The skull was distorted and, if any other parts of the skeleton happen to exist, none has yet been published in the scientific literature. It is also older than the date when genetics says that the human and chimp lineages diverged.

Predator's playground

Nevertheless, palaeontologists have been busy studying the abundant fossil material unearthed at the site, steadily building a picture of the environment in which Sahelanthropus eked out its existence.

In Late Miocene times, this area of Chad must have had a lake, because palaeontologists have found the fossilised remains of fish, amphibians and crocodiles.

But they have also found evidence of grasslands, gallery forest and a desert.

Researchers have discovered the fossilised remains of a wide variety of carnivorous mammals at Toros Menalla. Ending up in the sharp jaws of a predator must have been an ever-present threat for primates like Toumai.

Palaentologists had already reported finding remains of a large sabretooth cat from Toros Menalla known as Machairodus kabir which weighed in at 350-490kg.

Writing in the journal Comptes Rendus Palevol, Louis de Bonis from Poitiers University and colleagues add two new sabretooth species to the growing list of carnivores that stalked this region of central Africa in late Miocene times.

The big cat remains were unearthed during recent field expeditions and have been identified as new species belonging to the genus Lokotunjailurus and the genus Megantereon.

Forest refuge

Patrick Vignaud, director of Poitier University's Institute of Palaeo-primatology and Human Palaeontology, told BBC News the cats were about the same size as modern lions.

"With our present data, we don't know what precisely the interactions were between a primate and a big carnivore. But probably these interactions were not so friendly," said Professor Vignaud.

He told BBC News: "Sabretooths hunted all mammals; bovids, equids... and primates. The interactions were also more 'psychological', exercising a stress on potential prey. We can't prove it but it's probably important because in that case, primates had to live near closed environments like gallery forest."

While ancient primates like Sahelanthropus tchadensis gave sabretooth cats a wide berth, they may also have depended on these big carnivores - and others - for their survival.

Sabretooths would have hunted large herbivorous mammals, and probably left enough meat on their kills for scavengers like the jackal-sized Hyaenictherium and perhaps even primates like Sahelanthropus.

Some researchers have proposed that Toumai is more closely related to chimpanzees or gorillas. Even if this were the case, the discovery would be of great significance, as virtually no fossil ancestors of these great apes are known from Africa.

From the BBC:

Hair colour predicted from genes

By Paul Rincon Science reporter, BBC News

Scientists say they have developed a way to predict a person's probable hair colour using markers in their DNA.

The study paves the way for a forensic test that could estimate the hair colour of a suspect from DNA left at a crime scene.

The information could then be used to refine the description of an unknown but wanted person.

A Dutch-Polish team of researchers have published details in the journal Human Genetics.

The researchers found that it was possible to determine with an accuracy of more than 90% whether a person had red hair, with a similar accuracy for people with black hair

They could estimate with an accuracy of more than 80% whether a person's hair color was blonde or brown.

Predictive power

This new genetic approach is also able to differentiate between some hair colours that are similar, for example, between red and reddish blonde, or between blonde and dark blonde hair.

The DNA can be taken from blood, sperm, saliva or other samples that would be relevant in forensic case work, say the researchers.

Lead scientist Manfred Kayser, from Erasmus University Medical Center in Rotterdam, said: "That we are now making it possible to predict different hair colours from DNA represents a major breakthrough because, so far, only red hair colour, which is rare, could be estimated from DNA.

The researchers studied DNA and hair colour information from hundreds of Europeans. They investigated genes previously known to influence the differences in hair colour.

"We identified 13 'DNA markers' from 11 genes that are informative to predict a person's hair colour," said Professor Kayser, chair of the Department of Forensic Molecular Biology at Erasmus.

Emerging field

Predicting human "phenotypes" - a person's outward traits such as hair colour or eye colour - from DNA information is a newly emerging field in forensics.

Genetic profiling compares DNA at a crime scene with that of a known suspect or with other profiles in a database in search of a match. But researchers say that when this approach draws a blank, clues to the appearance of a suspect could provide valuable leads in an investigation.

But only a few phenotypic traits can currently be identified from DNA information with enough accuracy to have practical applications.

"This research lays the scientific basis for the development of a DNA test for hair colour prediction," said Professor Ate Kloosterman of the Netherlands Forensic Institute (NFI).

"A validated DNA test system for hair colour shall become available for forensic research in the not too distant future."

He added: "This new development results in an important expansion of the future DNA tool-kit used by forensic investigators to track down unknown offenders."

Professor Kayser's team at Erasmus University has already developed a test for eye colour based on DNA markers. In September they published details of a technique to estimate the age of a suspect from blood left at a crime scene.

The method exploits a characteristic of immune cells carried in the blood known as T cells. The approach enables scientists to estimate a person's age, give or take nine years either side.

From the BBC:

Ancient Jamaican bird used wings to go clubbing

By Richard Black Environment correspondent, BBC News

An extinct flightless bird from Jamaica fought rivals and predators using wings evolved into clubs, scientists suggest.

The boney bludgeons carried by Xenicibis xympithecus are unlike anything else known in the bird world - or in mammals, reptiles or amphibians.

Writing in the Royal Society journal Proceedings B, the scientists report finding bones that had apparently been broken by another bird's club.

The species may have survived until less than 10,000 years ago.

A member of the ibis family, it was probably about the size of a chicken, but with an infinitely more robust armoury.

Fossils show that the metacarpus - one of the "hand" bones - was elongated and much bigger than in related species, with very thick walls.

This allowed the wings to function "in combat as a jointed club or flail", the researchers write.

"We don't really know how they would have used these clubs, but we do know that modern ibises grab each other by the beak and pound away with their wings," said Nicholas Longrich, from Yale University in the US.

"And we analysed two bones that had been broken during fighting, including a humerus (upper arm bone) that had been snapped in half - it had started to re-heal, although the two ends hadn't knitted together," he told BBC News.

Dr Longrich's colleague in this research, Storrs Olson from the Smithsonian Institution, was one of the scientists who first identified Xenicibis xympithecus back in the 1970s.

A number of other birds are known to fight by whacking each other with their wings - including swans, who will also protect their young this way.

Some, including screamers, lapwings and and spur-winged goose, have evolved spurs to increase the damage they can wreak.

The extinct solitaire from the Indian Ocean island of Rodrigues - a cousin of the dodo - had bony growths colloquially known as "musketballs" on their wings, which appear to have served the same purpose.

"But among vertebrates - there's no animal of any sort that has anything like a limb modified as a club," noted Dr Longrich.

Julian Hume, an avian palaeontologist with London's Natural History Museum who was not involved in the research, noted that unlike most flightless birds, Xenicibis retained long wings, possibly making its flailing more powerful.

"Ibis young stay in the nest for a relatively long time," he said.

"So if they retained that feature, that suggests they needed it for defence against predators - and there were quite a few on Jamaica."

However, ibises also tend to be intensely territorial, so the flailing clubs may also - or alternatively - have found employment in disputes between individuals, probably with both sexes involved.

From the BBC:

Leatherback turtles tracked on Atlantic 'danger' trips

By Richard Black Environment correspondent, BBC News

Scientists have for the first time tracked leatherback turtles from the world's largest nesting site, in Gabon, as they traverse the South Atlantic.

Data from tags on their backs show they swim thousands of kilometres each year.

These journeys take them through areas where they are at high risk of being caught accidentally by fishing boats.

The leatherback is the world's biggest turtle and listed as Critically Endangered, largely because of poaching for eggs and snaring in fishing gear.

Typically between one and two metres long, the animals weigh up to three-quarters of a tonne and can swim across entire oceans, returning to their ancestral nesting sites to breed every few years.

First tracks

Writing in the Royal Society journal Proceedings B, an international group of researchers relate how they tagged 25 adult female leatherbacks (Dermochelys coriacea) from Gabon over a four-year period.

The Gabon nesting sites were identified in 2009 as the world's biggest, supporting an estimated population of 15-41,000 females.

"The reason for doing the project is to understand the turtles' movements, but the context is that the Pacific population recently went through a huge decline," said Matthew Witt from Exeter University, the study's lead author.

"Part of the reason for that is interaction with fisheries - so it seemed very pertinent to get a better understanding of what the South Atlantic leatherbacks are up to."

A study published last year estimated that millions of turtles had been killed in fishing gear over the last 20 years.

Although leatherbacks have been extensively tracked further north in the Atlantic and also in the Pacific, this is the first time that more than a few animals have been followed from the South Atlantic.

The tags affixed to the turtles' backs typically functioned for several months before either falling off, succumbing to battery failure or becoming clogged with seaweed so they refused to return data.

The South Atlantic leatherbacks adopted three different patterns.

Some swam west and remained in the tropical Atlantic waters. A second group swam south-west until they reached the coast of South America, and foraged in shallow waters there; while the remainder moved southwards down the western coast of Africa.

Why they should take these different routes is not clear.

But as hatchlings, they swim weakly and must go where the South Atlantic gyre sweeps them; and the scientists suspect that as adults, each turtle sticks with the path it took on its initial, involuntary foray.

Catching the drift

The global population of leatherbacks is not known, although estimates based mainly on data from nesting sites suggest a decline of up to 80% between 1982 and 1996.

In Malaysia, a site that had once supported 10,000 females contained just 37 in 1995.

Conservation initiatives appear to have halted the decline in some sites.

Egg-poaching does not appear to be a major threat in Gabon, where about 80% of the nesting areas lie inside National Parks.

But fishing could be. The turtles' routes take them through areas traversed by long-line fishing boats, which are known to catch turtles, and into coastal waters where entrapment in gillnets is a demonstrable threat.

The scientists calculate that the South Atlantic turtles travel the territorial waters of at least 11 nations - although the bulk of their time is spent in open ocean, where there are very few rules on fishing.

"This study gives us a really good idea where we should be focussing efforts to reduce bycatch," Dr Witt told BBC News.

"Over the last five or 10 years there's been quite a lot of research for example on using a different shape of fish hook that cuts the rate of unintentional catch for things like turtles while maintaining the intentional rate of fish catch.

"So I think we now need to push forward and say 'let's change all the hooks in these areas'."

From the BBC:

Wreckage is from 'pristine star'

By Jonathan Amos Science correspondent, BBC News

UK and US scientists have found the remnants of a star that exploded more than 13 billion years ago.

It would most probably have been one of the very first stars to shine in the Universe, they say.

All that is left of this pioneer is the gas cloud it threw out into space when it blew itself apart.

It was identified when its contents were illuminated by the brilliant light coming from the surroundings of a distant black hole.

The cloud's atoms occur in abundances that are quite unlike that found in the nearby cosmos today and are more what one would expect from stars that were originally made only of hydrogen and helium.

The research required the observations of two of the world's most powerful telescopes - the Keck facility in Hawaii and the Very Large Telescope in Chile.

It has been written up in the Monthly Notices of the Royal Astronomical Society.

'Holy Grail'

The study is said to provide fresh insight on key events in the earliest stages of the Universe, in particular it offers some new details on the endings of the so-called "Dark Ages", the period before the first stars formed.

"It's a period we know very little about, but the Universe at that time was a rather boring place, just filled with hydrogen and helium gas and not much else; there was no light - that's why it's called the Dark Ages," explained Professor Max Pettini at Cambridge's Institute of Astronomy, UK.

"And then somehow from that initial state it changed into this wonderful mix of stars and planets and galaxies that we see around us today."

Working on the Keck and VLT, Pettini's team probed the composition of distant clouds of gas known as "damped Lyman alpha systems". They did this using the light provided by quasars, extremely luminous galaxies whose brilliance is powered by a mighty black hole at their core.

The investigation identified one particular DLA that had a unique chemical signature - one where the ratio of carbon to iron atoms was 35 times greater than what can be measured in the Sun. It enabled the group to infer that the gas was released by a star 25 times more massive than our star and which originally consisted of only hydrogen and helium - exactly the type of star expected to have ended the Dark Ages.

"The first stars have been a bit like the Holy Grail for astronomers," said Professor Pettini, who led the research with PhD student Ryan Cooke.

"We think that they all lived very short and furious lives. They are all dead now, and there is no way for us even with the most powerful telescopes to observe them directly. So, what we have found is the remnants of one of these first stars to form in the Universe, and the elements carbon, oxygen and iron and pristine gas in a mix that has never been seen before."

Next generation

The results of the study, conducted with partners at the California Institute of Technology (Caltech), will feed into the theoretical framework scientists are building to describe this early epoch.

Scientists believe the very first stars to shine in the Universe were hot giants that fundamentally changed the cosmic environment.

Not only did they seed the cosmos with the heavier elements needed to make planets, but their intense ultraviolet radiation also "fried" the neutral gas around them. The consequences of this latter process are evident even today in the diffuse plasma that fills the space between the galaxies.

"This was only a first step; it was like finding some fossil," Professor Pettini told the BBC.

"Now that we have discovered how to find such fossil evidence, we are much better placed for finding other examples of these particular clouds in the distant Universe that hold the special clues; and then progress from there and really breakthrough what has been called the last frontier in observational astronomy."

Finding out any information about this early period, just a few hundred million years after the Big Bang, is a tour de force because it takes existing technology such as the Keck and VLT right to the limits of their capability.

Only with the next generation of observatories - super telescopes with mirrors tens of metres in diameter - can scientists hope to probe more widely into the circumstances that ended the Dark Ages.

The European Southern Observatory Organisation, which runs the VLT, plans to build a telescope with a 42m-wide mirror, and Caltech is involved in a project to build one with a mirror that is 30m in diameter.

An interesting idea. From the BBC:

Smart wrapping developed to detect 'off food'

A new generation of smart packaging - which flags up when food is going off - is being developed in Glasgow.

Researchers from Strathclyde University are working on indicators made from "intelligent plastics" which change colour when food loses its freshness.

They hope to have a commercially viable product available soon which will improve food safety and cut waste.

The project is being supported with £325,000 in funding from the Scottish Enterprise Proof of Concept programme.

UK households are estimated to throw out about 8.3 million tonnes of food each year - most of which could be eaten.

It is also thought that there are about one million cases of food poisoning annually in Britain.

The Strathclyde University team hopes new smart wrapping will alert consumers when food is about to lose its freshness because it has broken or damaged packaging, has exceeded its "best before" date or has been poorly refrigerated.

'Atmosphere packaging'

Freshness indicators currently used across the food industry usually take the form of labels inserted in a package but these come at a significant cost.

Strathclyde researchers are looking to create a new type of indicator which is part of the wrapping itself and subsequently much cheaper.

The indicator it is working on will change colour when the freshness of the food deteriorates past a certain level.

It will be used as part of a form of food packaging known as modified atmosphere packaging, which keeps food in specially-created conditions that prolong its shelf life.

Professor Andrew Mills, who is leading the project, said: "At the moment, we throw out far too much food, which is environmentally and economically damaging.

"Modified atmosphere packaging is being used increasingly to contain the growth of organisms which spoil food but the costs of the labels currently used with it are substantial. We are aiming to eliminate this cost with new plastics for the packaging industry.

"We hope that this will reduce the risk of people eating food which is no longer fit for consumption and help prevent unnecessary waste of food. We also hope it will have a direct and positive impact on the meat and seafood industries."

The Strathclyde team believes its work could resolve potential confusion about the different significances of "best before" dates and "sell-by" dates.

It could also help to highlight the need for food to be stored in refrigerators which are properly sealed.

From the BBC:

Ammonite diet revealed in X-rays

By Jonathan Amos Science correspondent, BBC News

Ask someone to name their favourite fossils and the chances are they will point to the ammonites.

These coiled remains of ancient squid-like creatures are in every child's rock collection.

The animals were a big success, filling the oceans for 350 million years before going extinct with the dinosaurs.

Now, exquisite X-ray images featured in Science magazine are providing new insights on how the ammonites lived and perhaps also on why they died out.

The pictures have been produced by a team of French and American researchers using the European Synchrotron Radiation Facility (ESRF) in Grenoble.

They reveal the mouthparts of three ammonite specimens discovered in Belle Fourche, South Dakota, US, a place renowned for the excellent preservation of fossils.

The fossils are actually from a grouping of straight, or uncoiled, ammonites known as Baculites but the implications should hold across a great swathe of species.

Beautiful 3D reconstructions lay bare the physical characteristics of the molluscs' jaws and a tongue-like structure called the radula.

The imagery is important because of what it says about the feeding habits of these prehistoric marine invertebrates.

Although "ten a penny" in terms of their abundance, the fossils still hide some secrets about the living animals' ecology.

"Ammonites are iconic fossils; everyone knows them, but actually we have very few data on the animals themselves," explained Isabelle Kruta from the National Museum of Natural History, Paris. "We have their shells but beyond that it's all been speculation."

With no direct counterpart today, it has been difficult to nail down the ammonites' true place in the ancient food chain.

But the analysis by Kruta and her colleagues indicates their ammonites would have dined on small organisms floating in the water, such as zooplankton, tiny crustaceans, and even other petite ammonites.

In one of the specimen's mouths the team found the remains of what was probably the animal's last meal, diced up by the jaws and the teeth-laden radula.

If plankton provided the major part of the ammonite diet then this could help explain their extinction 65 million years ago, the team believes.

The asteroid or comet impact widely implicated in the dinosaurs' demise would also have damaged plankton production in the oceans.

Depleted food resources could have been a decisive factor therefore in pushing the ammonites over the edge.

"Pretty much all the community thought they were carnivorous but we didn't know exactly what they were eating," said Ms Kruta.

"People have pictured them catching fish or eating clams. But we've found they couldn't eat large, hard prey; they were not able to tear apart pieces of flesh," she told BBC News.

Ammonites were cephalopods; their nearest living relatives are animals like squid, octopus and cuttlefish.

And although the modern nautilus looks superficially like an ammonite, it is in fact a more distant cousin. Indeed, the nautilus has far more robust mouth parts; and can scavenge a wide variety of food sources. This fact may in part explain why the ancestors of the modern nautilus survived the space impact and the ammonites did not, say the researchers.

From their first appearance in the Early Devonian Period (about 400 million years ago), ammonites underwent an explosive diversification.

Today, many thousands of species are known from the fossil record.

This great wealth of different forms through Earth history means they can be used as a dating tool by geologists - if a rock contains a particular fossil ammonite then that rock must be of a certain age.

The ESRF has pioneered the X-ray study of such palaeontological specimens.

The machine produces an intense, high-energy light that can pierce just about any material, revealing its inner structure.

Its advantage is that the investigation is non-destructive - it provides information that could otherwise only be obtained by cutting into a fossil.

The X-ray microtomography data also captures very fine details which can then be rendered virtually in a 3D form and manipulated on a computer.

2 of 3

3 of 3

This data can even be sent to a printer to make oversized plastic models that scientists can play with to try to reconstruct the proper alignment of anatomical features which in the fossil itself may have been preserved in a jumbled heap.

For example, Ms Kruta uses a 15cm-long plastic print of a radula tooth to demonstrate the 2mm-long original that remains hidden away inside a fossil.

"For the radula you have to imagine a kind of band with something like 50 rows of teeth, and for each row you have nine teeth; and for some of the teeth you can have up to 17 cusps. It looks like a comb," said Dr Paul Tafforeau from the ESRF.

"In one of our specimens we found its last meal.

"The preservation meant we had both jaws in position with the radula, and then inside we had planktonic animals including one that had been cut in two. You can even see its internal organs," he told BBC News.

From the BBC:

Led by Dr Antonia Monteiro, the team found that the white "pupil" at the centre of each butterfly's eye spot reflects different amounts of ultraviolet (UV) light, depending on what temperature the butterfly was reared at when a larvae.

"Cool temperatures increase the UV reflectance of female sexual ornaments, warmer temperatures increase the UV reflectance of male sexual ornaments. These changes are not visible to humans because we do not see UV," explains postdoctoral fellow Dr Kathleen Prudic.

However butterflies can see UV, so by developing more attention-grabbing eye spots, females born in the dry season are able to attract males.

Researchers suggest that female butterflies may take over the performance role in order to survive the adverse conditions of the dry season.

By actively attracting mates and mating more often researchers have found that the dry season females in their studies live longer.

Butterflies have evolved complex and dynamic mating behaviours that can respond to predictable changes in their environment Kathleen Prudic

This evidence supports previous studies that suggest female butterflies benefit from receiving sperm and associated nutrients during mating.

"The implications of these findings build upon a growing understanding that butterflies and other insects have evolved complex and dynamic mating behaviours that can respond to predictable changes in their environment," says Ms Prudic.

Squinting bush brown butterflies are native to sandy forest habitats from central to south eastern Africa.

Three to five generations are born per year and developing caterpillars experience considerably different temperatures between wet and dry seasons.