Sunday, August 31, 2014

Greenhouse gas fear over meat eating

Global consumption of meat needs to fall - to ensure future demand for food can be met and to help protect the environment - a study says.

Research from Cambridge and Aberdeen universities estimates greenhouse gases from food production will go up 80% if meat and dairy consumption continues to rise at its current rate.

That will make it harder to meet global targets on limiting emissions.

The study suggests a weekly limit of two portions of red meat and five eggs.

However that call comes as the world's cities are seeing a boom in burger restaurants.

The research highlights that more and more people from around the world are adopting American-style diets, leading to a sizeable increase in meat and dairy consumption.

It says if this continues, more and more forest land or fields currently used for arable crops will be converted for use by livestock as the world's farmers battle to keep up with demand.

'Start Quote

Agricultural practices are not necessarily at fault here - but our choice of food is'

End Quote Lead researcher, Bojana Bajzelj

Deforestation will increase carbon emissions, and increased livestock production will raise methane levels and wider fertiliser use will further accelerate climate change.

The lead researcher, Bojana Bajzelj from the University of Cambridge, said: 'There are basic laws of biophysics that we cannot evade.'

'The average efficiency of livestock converting plant feed to meat is less than 3%, and as we eat more meat, more arable cultivation is turned over to producing feedstock for animals that provide meat for humans.

'The losses at each stage are large, and as humans globally eat more and more meat, conversion from plants to food becomes less and less efficient, driving agricultural expansion and releasing more greenhouse gases. Agricultural practices are not necessarily at fault here - but our choice of food is.'

The report says the situation can be radically improved if farmers in developing countries are helped to achieve the best possible yields from their land.

Another big improvement will come if the world's population learns to stop wasting food.

The researchers say if people could also be persuaded to eat healthier diets, those three measures alone could halve agricultural greenhouse gas levels from their 2009 level.

The study is the latest to warn of the planetary risks of eating intensively-produced meat and dairy produce. Scientists worried about climate change are increasingly making common cause with health experts concerned about the obesity pandemic.

But many people are voting with their wallets and their bellies - as burger bars expand, mushroom burgers are not yet top-selling items.

Follow Roger on Twitter: @rharrabin

Xenon and argon banned for athletes

Doping experts have yet to find an effective test for athletes doping with xenon and argon, despite the fact that a worldwide ban has been introduced.

The new ban has been ordered by the World Anti-Doping Agency (Wada), which runs drug testing across many sports.

It follows concerns that athletes were breathing these so-called noble gases to encourage the growth of red blood cells that boost stamina.

But despite being piloted, a valid test is not yet ready, the agency says.

Ignoble prize

The idea of doping with gases more usually associated with arc welding, neon light bulbs and anaesthesia may seem bizarre, but Wada believes there is enough evidence of their enhancement potential to ban them.

'Start Quote

We had some preliminary pilot results that do indicate that detection is not too much of an issue'

Media reports earlier this year indicated that athletes in Russia have been using the gases for years as a means of boosting their stamina ahead of international competitions.

Indeed the company that developed techniques to help athletes prepare using xenon, has a ' badge of honour' on its website from the Russian Olympic Committee for 'the organisation and conduct of inhalation remediation'.

How xenon gas may boost performance

Inhaling xenon, mixed with oxygen, is believed to improve stamina because it increases the body's production of a protein known as hypoxia inducible factor 1, or HIF1.

In turn this stimulates the production of natural erythropoietin (EPO) which regulates the number of red blood cells. The more of these cells, the more oxygen you can carry, and the greater your athletic stamina.

Doping with artificial EPO has been one of the biggest threats to the integrity of sport over the past 20 years. The clampdown on using the drug has seen sports scientists develop other methods including the use of xenon and argon.

Earlier this year Wada's executive committee decided to ban these two named gases by adding them to the prohibited list from this month.

'We had serious information that xenon was being used,' Wada's science director Dr Olivier Rabin told BBC News.

'We believe it has been used in the preparation for some major events.'

Now that xenon and argon are banned, the agency needs to have an effective test for the gases.

Developing one is not an easy task.

As well as being present in the air we all breathe, albeit in minute quantities, xenon is also used in many countries as an anaesthetic.

Dr Rabin says that Wada scientists are close to developing a direct test for the gas.

'We had some preliminary pilot results that do indicate that detection is not too much of an issue but we just need to make it solid and robust in the anti-doping context and make sure that any result in the future will be accepted by a court.'

Validating a test like this to the level that it can stand up in the Court of Arbitration for sport is not easy. When I asked Dr Rabin if the test would be in place by the end of the year, he was unable to give that reassurance.

Gas facts

  • Xenon and argon are called noble gases because they are inert and don't react with anything else

  • At less than 100 parts per billion, xenon is one of the rarest natural gas components in the atmosphere

  • Xenon has been used in flash bulbs, lamps and in medical imaging

  • In Russia, xenon has been used for decades as an anaesthetic because of its lack of side effects

'I cannot give you a specific date, we usually do not, what I can tell you is that the science is very solid and certainly we will do our best, now that the gases are on the prohibited lists to make sure there are detection methods available as soon as possible.'

Other researchers though are not convinced that a reliable test will be quickly forthcoming.

They also question why Wada has banned the use of these gases but allows athletes to use oxygen tents or hypoxic chambers that mimic the effects of sleeping at altitude with the aim of producing a similar blood boosting effect as xenon.

'Their whole argument is based on false grounds,' said Dr Ben Koh, a former athlete and an expert on sports medicine.

'What is happening among elite athletes is a very artificial process, involving hypoxic chambers before competitions. This is artificial, and it is no different from the artificiality of xenon.'

Secondary benefits

Wada says that there could be dangers to the health of the athletes if they use large amounts of xenon or argon and this another reason for the ban, as well as the performance enhancement.

Dr Koh rejects this argument.

'I would argue that xenon is actually safer than hypoxic tents, in terms of heart failure, trauma to the ear and to the lungs, the risks are very well documented from hypoxic tents, on the other hand, xenon gas from the published literature seems to be quite safe.'

There is a possibility that Wada has information that xenon can have other sports enhancing effects in athletes that go beyond an increase in stamina.

'The concern would be that there's some secondary benefit not due to HIF1, and that seems to me entirely possible,' said Dr Chris Cooper, from the University of Essex, who has researched the science of doping.

'I'm surprised if the effect in these animal models is due to increased hematocrit, there is something else going on.'

Wada say they have named xenon and argon for the sake of legal clarity.

I asked Dr Rabin what would happen if similar inert gases such as krypton, say, are shown to have a similar effect.

'Xenon and argon are only examples, it is not a closed list as we do have for narcotics - tomorrow any gas that has a HIF1 activation is de facto prohibited.'

So no krypton-powered super athletes then?

'Absolutely not!'

Follow Matt on Twitter @mattmcgrathbbc.

Iceland issues new volcano alert

Friday, August 29, 2014

Scientists solve 'sliding rocks' puzzle

Scientists have finally solved the mystery of how rocks can move across the flat ground of a dry lake bed in Death Valley, California.

Visitors have long been puzzled by the sight of boulder tracks criss-crossing a dusty bowl known as the Racetrack Playa in Death Valley National Park. But two researchers now say the rocks - which can sometimes be heavy and large - are propelled along by thin, clear sheets of ice on breezy, sunny days. They call it 'ice shove'. 'I'm amazed by the irony of it all,' paleobiologist James Norris tells the LA Times. 'In a place where rainfall averages two inches a year, rocks are being shoved around by mechanisms typically seen in arctic climes.'

The findings are based on a lucky accident by James Norris and his cousin Richard Norris - while they were studying the sliding rock phenomenon. They actually witnessed the boulders moving in December when they went to check their time-lapse cameras in the valley. 'There was a pop-pop-crackle all over the place in front of us and I said to my cousin, 'This is it',' Richard Norris says in the science journal Nature. They watched some 60 rocks sail slowly by, leaving the well-known snaking trails in the ground. 'A baby can get going a lot faster than your average rock,' Norris notes. The rocks also don't slide around very often - scientists estimate only a few minutes out of a million - which is why the event has not been noticed before.

Use #NewsfromElsewhere to stay up-to-date with our reports via Twitter.

Iceland eruption triggers red alert

The Icelandic Met Office has raised its aviation warning level near the Bardarbunga volcano to red after an eruption began overnight.

Scientists said a fissure eruption 1km (0.6 miles) long started in a lava field north of the Vatnajokull glacier.

Civil protection officials said Icelandic Air Traffic Control had closed the airspace above the eruption up to a height of 18,000ft (5,500m).

The volcano has been hit by several recent tremors.

The fissure eruption took place between Dyngjujokull Glacier and the Askja caldera, a statement from the Department of Civil Protection said.

The area is part of the Bardabunga system.

'Scientists who have been at work close to the eruption monitor the event at a safe distance,' the statement added.

'The Icelandic Met Office has raised the aviation colour code over the eruption site to red.'

It added that no volcanic ash had so far been detected but a coast guard aircraft was due to take off later to survey the site.

Until now the Met Office has kept its aviation warning level - indicating the potential threat of volcanic activity to air travel - at orange, its second-highest.

On Thursday, scientists said they were examining several 'cauldrons' found near Bardarbunga volcano that could potentially be a sign of an eruption.

The cauldrons, depressions in the volcano's surface, each between 10-15m (49 ft) deep and 1km (0.6 miles) wide, were seen during a flight on Wednesday.

Bardarbunga is part of a large volcano system hidden beneath the 500m-thick (1,600ft) Vatnajokull ice cap in central Iceland.

Iceland's Eyjafjallajokull volcano erupted in 2010, producing ash that disrupted air travel across Europe.

Legal challenge to badger cull fails

Thursday, August 28, 2014

UN seeks climate change 'Malala'

Five hundred people are to learn if they have won the chance to vent their frustration at world leaders over the stalemate on climate policy.

They applied to address more than 100 heads of state and government at next month's UN climate summit in New York.

Many of the candidates are established climate campaigners; they span 115 countries and include victims of natural disasters like Typhoon Haiyan.

Just one winner will be chosen to speak at the plenary session.

The rules stipulate that it must be a woman under 30 - which the organisers say will give a voice to the next generation. They maintain that the majority of the poorest in society are women, so they are most likely to suffer worst from climate change.

The UN describes this as its first open competition to select members of the public to address world leaders.

It attracted 544 applicants to email mini-videos urging elected leaders to cut the emissions of CO2 that are driving climate change and ocean acidification.

The organisers are hoping the chosen one will electrify the conference as Pakistani schoolgirl Malala Yousafzai did when addressing the UN in 2013 as part of her campaign to ensure free compulsory education for every child.

Malala had survived being shot in the head the previous year by Taliban gunmen because of her campaign for girls' rights.

Controversial move

'Start Quote

Fully combating climate change is going to require women's full empowerment everywhere'

End Quote Susan Alzner UN Non-Governmental Liaison Service

The ability to scour the world for speakers has been enabled by the revolution in social media. The process is being coordinated by just two UN staff.

On Friday, the Secretary-General's office will choose 38 of the applicants to participate in the conference, three of them to join a panel.

All will be young people or people working with youths.

The 'young women only' rule for the main plenary slot is likely to attract controversy. Some will support it, others may find it sexist, patronising or even manipulative.

The main organiser, Susan Alzner from the UN Non-Governmental Liaison Service, defended her plan.

She told BBC News: 'If you consider the huge challenges that still exist for so many women across the world to realise their rights to participate in government and how important it is to show young women that they have this right, then we should give the one available slot to speak to more than 100 heads of state to a young woman.

'Women disproportionately experience the impacts of climate change in particular because 70% of the lowest income people worldwide are women.

'Fully combating climate change is going to require women's full empowerment everywhere. It is essential that we give women the space to speak on this critical topic that is an existential threat to humanity.'

Breadth of choice

Some of the would be speakers are already known to a global audience, like the young poet and activist Kathy Jetnil-Kijiner, whose Marshall Islands home is threatened by sea level rise.

Some audition videos are demotic whilst others are softly persuasive, like that from Vanessa Dalmau - a campaigner in the Dominican Republic for the green group

She hopes to tell world leaders: 'I put myself in your shoes and think about the political price you think you will have to pay (for policies to combat climate change). But the rewards we can all reap are larger. And people are ready to follow leaders who take bold action on climate change. Will you be that leader?'

The organisers are delighted by the breadth of applicants. But among them is a young woman whose experience counsels caution: Christina Ora from Solomon Islands has already addressed climate negotiators in 2009.

She told them: 'I was born in 1992. You have been negotiating all my life (on climate change). Stop negotiating away our future.'

Her address was made to delegates at the disastrous Copenhagen climate summit. Listening to impassioned youth is one thing: changing current economic policies to combat a risk of uncertain magnitude is another.

Follow Roger on Twitter.

DNA tells story of Arctic peopling

A new 'genetic prehistory' provides the best picture ever assembled of how the North American Arctic was populated, from 6,000 years ago to the present.

DNA sequences from living and ancient inhabitants show a single influx from Siberia produced all the 'Paleo-Eskimo' cultures, which died out 700 years ago.

Modern-day Inuit and Native Americans arose from separate migrations.

Previously our understanding of this history was based largely on cultural artefacts, dug up by archaeologists.

The study, which has more than 50 authors hailing from institutions across the globe, was published in the journal Science.

'Start Quote

A single founding population settled, and endured the harsh conditions of the Arctic, for almost 5,000 years'

End Quote Dr Maanasa Raghavan Natural History Museum of Denmark

Multiple models

Researchers of North American prehistory have long disagreed about the lineages of Arctic peoples, ranging from the first arrivals who mostly hunted ox and reindeer, through at least four other cultural groupings, to the modern Inuit and their marine hunting culture.

'Since the 1920s or so, it has been heavily discussed what is the relationship between these cultural groups,' said senior author Prof Eske Willerslev from the Natural History Museum of Denmark, which is part of the University of Copenhagen.

'All kinds of hypotheses have been proposed. Everything from complete continuity between the first people in the Arctic to present-day Inuits, [while] other researchers have argued that the Saqqaq and the Dorset and the Thule are distinct people.'

These three broadly-grouped cultures all occupied the north of North America: the Saqqaq until 2,500 years ago, followed by a series of Dorset cultures and then the Thule (Inuit ancestors) from about 1,000 years ago.

Using DNA from more than 150 ancient human remains, the researchers showed that all the Saqqaq and Dorset peoples, further bundled together as Paleo-Eskimos, represent a single genetic lineage. They all stem from a migration across the Bering Strait from Siberia that began some 6,000 years ago.

'A single founding population settled, and endured the harsh environmental conditions of the Arctic, for almost 5,000 years - during which time the culture and lifestyle changed enough to be represented as distinct cultural units,' explained Dr Maanasa Raghavan, first author of the new paper.

Four waves of arrivals

  • Paleo-Eskimos (beginning around 6,000 years ago) including Saqqaq and three separate Dorset cultures

  • Thule people (beginning around 1,000 years ago), ancestors of the modern-day Inuit

  • Two waves further south, giving rise to different groups of Native American ancestors

She explained that this was unusual in the study of ancient people, and suggested that cultural changes, identified through tools and other remains, are not the best way to gauge ancient population movements.

History of violence?

The findings also confirm that before the Paleo-Eskimo culture suddenly disappeared around 700 years ago, there was no mixing between those communities and the Inuit ancestors, who arose from a second, distinct Siberian migration.

Carbon dating suggests they may have overlapped in Greenland and northern Canada for up to several centuries, but cultural remains do not betray any interaction: the Paleo-Eskimos continued to use flaked stone tools, for example, while the Thule used ground slate.

The lack of any genetic cross-over may indicate that the previous inhabitants died out before the Thule arrived; it also 'raises the question', according to Prof William Fitzhugh, another author of the study, of a possible 'prehistoric genocide'.

Prof Fitzhugh, from the Smithsonian Institute in Washington DC, said the disappearance of the Paleo-Eskimos - 'within the space of 100 or 150 years, a whole population, a whole cultural tradition' - was something of a mystery.

And yet Inuit legend suggests only friendly relations between their Thule ancestors and the 'gentle giants' who preceded them.

Prof Fitzhugh emphasised he was only speculating: 'We don't have any good evidence that there was hostility between the Dorset people and the Thule people.'

There is much more to figure out, he said, describing the new work as 'an opening chapter in the genetic history of the New World Arctic'.

Overall, the findings add a 'fourth wave' to existing models of Arctic settlement in the New World, by confirming that all the Paleo-Eskimos arose from a distinct, early migration.

After comparing ancient samples with genomes from living people, the researchers concluded that subsequent, separate waves gave rise to the Thule people (and their descendents the Inuit), as well as two distinct groups of Native Americans further south.

Genetic clues to spread of Ebola

Scientists have tracked the spread of Ebola in West Africa, revealing genetic clues to the course of the outbreak.

Genetic analysis of patient samples suggests the virus spread from Guinea to Sierra Leone at a single funeral.

The virus is mutating and must be contained rapidly, warn African and US experts. But they say there is no evidence the virus is changing its behaviour.

The current outbreak is the largest ever, with more than 3,000 cases.

The number of cases could exceed 20,000 before the outbreak is stemmed, according to the World Health Organization.

'We've uncovered more than 300 genetic clues about what sets this outbreak apart from previous outbreaks,' said Stephen Gire from the Broad Institute and Harvard University in the US.

'Although we don't know whether these differences are related to the severity of the current outbreak, by sharing these data with the research community, we hope to speed up our understanding of this epidemic and support global efforts to contain it.'

The data, published in Science, suggests the virus made the leap from animals to humans only once in the current outbreak.

'Start Quote

Clearly this virus is evolving, but what's not clear is whether or not the mutations it's accumulating affect the way it behaves.'

End Quote Prof Jonathan Ball Nottingham University

The strain emerged in Central Africa in the past 10 years, probably carried by animals such as fruit bats or primates.

The first human cases appeared in Guinea, then the disease spread to Sierra Leone, reportedly at the funeral of a traditional healer.

There is evidence the virus is mutating, 'underscoring the need for rapid containment', the team writes in Science.

'The longer the outbreak happens, the more opportunity the virus has to accumulate mutations,' Dr Gire told the BBC.

But he said there was no evidence at present that the virus was changing its behaviour and becoming better adapted to humans.

Commenting on the research, Prof Jonathan Ball, a virus expert at Nottingham University, said: 'Clearly this virus is evolving, but what's not clear is whether or not the mutations it's accumulating affect the way it behaves.'

The genetic samples came from 78 patients at a hospital in Sierra Leone who were infected in May and June.

These were compared with existing virus samples from Guinea.

Five of the 58 experts named on the paper died from Ebola in Sierra Leone during the study.

Dead stars 'can re-ignite' and blow

Iceland examines volcano 'cauldrons'

Scientists in Iceland say they are examining several 'cauldrons' found near Bardarbunga volcano, which could potentially be a sign of an eruption.

The cauldrons, depressions in the volcano's surface, each between 10-15m (49 ft) deep and 1km (0.6 miles) wide, were seen during a flight on Wednesday.

Iceland's Met Office said they were formed 'as a result of melting, possibly a sub-glacial eruption.'

Bardarbunga volcano has been hit by several recent tremors.

The area experienced a magnitude 5.7 earthquake on Tuesday. Experts say these earthquakes are caused as magma flows beneath the ground, cracking the rocks as it moves.

The Met Office has kept its aviation warning level - indicating the potential threat of volcanic activity to air travel - at orange, its second-highest.

'Sinkholes formed'

Scientists discovered the new cauldrons south of the Bardarbunga volcano during a surveillance flight over Vatnajokull glacier on Wednesday night, the Met Office and Civil Protection Department said.

It is not clear when they were formed, and the data is still being examined, they said.

They added that they had not observed increased tremors in the area so far.

Meanwhile, the University of Iceland tweeted: 'New fractures and sinkholes seen on #Bardarbunga during surveillance flight tonight. Data currently being evaluated by our geologists & IMO [Icelandic Met Office]'.

However it cautioned that the sighting was limited by poor visibility, and said more information would be available after a second surveillance flight on Thursday morning.

Flooding risk

Bardarbunga is part of a large volcano system hidden beneath the 500m-thick (1,600ft) Vatnajokull glacier in central Iceland.

The authorities said on Saturday that a small eruption had taken place under the Dyngjujokull ice cap, part of the same volcano system, but that there were no signs that gases or ash had broken through the ice.

The region, located more than 300km (190 miles) from the capital Reykjavik, has no permanent residents but sits within a national park popular with tourists.

Officials have previously warned that any eruption could result in flooding north of the glacier.

Iceland's Eyjafjallajokull volcano erupted in 2010, producing ash that disrupted air travel across Europe.

UK Ebola vaccine trial to start

A trial vaccine against Ebola could be given to healthy volunteers in the UK in September, according to an international health consortium.

The vaccine uses a single Ebola virus protein to stimulate an immune response but cannot cause someone who is given it to become infected, scientists say.

The trial will start as soon as ethical approval is granted, experts at the Wellcome Trust say.

If the vaccine works well, the trial will extend to The Gambia and Mali.

The latest figures show that more than 1,550 people have died from the Ebola virus, with more than 3,000 confirmed cases - mostly in Guinea, Liberia and Sierra Leone.

The study will run alongside similar trials in the United States.

Wednesday, August 27, 2014

Memories 'flipped' from bad to good

By artificially activating circuits in the brain, scientists have turned negative memories into positive ones.

They gave mice bad memories of a place, then made them good - or vice versa - without returning to that place.

Neurons storing the 'place' memory were re-activated in a different emotional context, modifying the association.

Although unlikely to be applied in humans with traumatic memories, the work sheds new light on the details of how emotional memories form and change.

The research is is published in the journal Nature.

Incremental progress

'Emotion is intimately associated with memories of past events and episodes, and yet the 'valence' - the emotional value of the memories - is malleable,' said the study's senior author Prof Susumu Tonegawa, from the Riken-MIT Center for Neural Circuit Genetics in Massachusetts, US.

He offered examples of a mugging, or a blissful holiday, which might make you fearful of a particular street, or fond of a beach.

'Start Quote

It occurs without the mice ever being brought back to the original place... All the manipulation is done from within the brain'

End Quote Dr Roger Redondo Riken-MIT Center for Neural Circuit Genetics

We all know that these sorts of emotional associations can be changed by a new, contrasting experience. Your favourite seaside memories, for example, might be soured by news of a shark attack.

Therapists already use this malleability in their efforts to treat trauma victims or people with depression, attempting to replace negative associations with positive ones.

Prof Tonegawa's team has unpicked some of the networks that make this happen inside the brain.

Two years ago, they showed they could label the cells storing a new, fearful memory in a mouse's brain, and turn them on again at a later date to cause fearful behaviour.

Then in 2013, they labelled a memory of a place and later reactivated it, while giving the mice small electric shocks. This created a false, fearful association with the original place.

Now they have managed to actually switch the emotional, fearful - or cheerful - content of a memory, from one extreme to the other.

Re-wired connections

Male mice were given a negative experience, consisting of small electric shocks, in a particular room, and the neurons working to store that memory were labelled using 'optogenetics'.

Optogenetics: switches for brain cells

  • Developed in flies, and then mice, during the early 2000s

  • Now used in neuroscience labs all over the world

  • Allows researchers to control neurons (brain cells) with coloured light

  • Involves genetic installation of light-sensitive ion channels, which change the flow of electrical charge and activate or silence neurons

  • To deliver the light, a thin optical fibre can be implanted into the brain

  • Much more precise than older techniques, such as stimulating parts of the brain with electric current

  • Used in this study to turn specific neurons on, but a range of channels that respond to different colours of light can be used to switch neurons both on and off

  • Hotly tipped for a Nobel Prize in the future

This is a technique that effectively installs a switch in those neurons, allowing them to be turned on again at will. The trigger used to stimulate them is a beam of blue light, sent into the brain by an optical fibre.

The next day, with the mouse in a different room, stimulating the labelled neurons in this way effectively 'reactivated' the original, fearful memory. When the mice were offered a choice between having the blue light on or off, they chose to leave it off.

But next, the researchers stimulated the labelled neurons while they gave the mouse a positive emotional cue (a female for company), in an attempt to 'flip' the emotional association of the stored memory.

Sure enough, offered the same choice again, the mice now wanted the blue light switched on: the original memory trace had been altered, and now they liked it.

Importantly, when returned to the original room, in the absence of any brain stimulation, the mice were less afraid than after the first round of training. Their memory of that place had changed - for the better.

The whole procedure also worked in the other direction, allowing the researchers to engineer a corresponding flip from an original positive memory to an artificial negative one.

By installing the optogenetic switches in different parts of the brain, the team also established that the memory changes came with adjustments in the connections between the hippocampus, which stores spatial information, and the amygdala, which drives emotional responses.

The scientists now believe that a place memory, stored in brain cells of the hippocampus, can 'call up' different sets of neurons in the amygdala, invoking either good or bad emotions - and their experiments tweaked that wiring, so that the original memory produced an altered emotional response.

'Start Quote

[This will] help us understand the proportion of cells that are involved when you have to change a memory from a bad one into a good one... It gives us an idea of the scale of the problem'

End Quote Prof Richard Morris University of Edinburgh

'We changed the way the mice react to a memory, without any drugs,' said Dr Roger Redondo, one of Prof Tonegawa's colleagues and the paper's first author.

Importantly, he added, '[This] occurs without the mice ever being brought back to the original place where the memory was formed. All the manipulation is done from within the brain.'

Of mice and men

It is difficult to know, however, whether the artificial recollections, driven by beams of blue light inside a mouse's brain, are similar to memories as we know them.

'We can't ask the mouse what it's thinking,' commented Prof Richard Morris, an eminent memory researcher from the University of Edinburgh who was not involved in the study.

'All we can do is ask the mouse, if I turn this light on, how are you going to behave in relation to whatever gets evoked?'

Prof Tonegawa also points to the consistent behaviour reported in his team's results. 'The mouse is obviously expressing the consequences of recall in its behaviour - so therefore, we assume that the mouse has the sensation of recall.'

In terms of whether their findings can be directly applied to humans, the researchers are cautious.

'There may be a few years of work ahead, but you never know,' said Dr Redondo. 'Technology is moving faster and these optogenetic tools keep advancing.'

Prof Morris agreed that this was something of a long shot - but he told BBC News the work was valuable nonetheless.

'Nobody's going to be queuing up to have light guides inserted into their brain and have blue light shone down into it.

'But [these results will] help us understand the proportion of cells that are involved when you have to change a memory from being a bad one into a good one - are we dealing with changing 50% of the cells in the amygdala, or are we dealing with 1% or even less?

'It gives us an idea of the scale of the problem.

'I think that's valuable, that's important - to move beyond just a behavioural understanding, but to have a deeper understanding of the clinical task in front of us.'

Follow Jonathan on Twitter.

Lockheed Martin in space junk deal

US defence giant Lockheed Martin has struck a deal with an Australian technology firm to track space debris that can damage satellites.

It has signed a 'strategic co-operation agreement' with Canberra-based Electro Optic Systems (EOS) to build a new tracking station in Western Australia.

The site will employ advanced optical and laser technology to detect, track and identify specific space objects.

Debris threatens orbiting satellites daily and can cause millions in damage.

'Ground-based space situational awareness is a growing priority for government and commercial organisations around the world that need to protect their investments in space,' said Lockheed Martin Space Systems executive vice president Rick Ambrose in a statement.

'We'll offer customers a clearer picture of the objects that could endanger their satellites, and do so with great precision and cost-effectiveness.'

There are nearly 2,000 commercial and government satellites orbiting the Earth.

However, they face up to 200 threats a day from debris as small as a fingernail given they are travelling at speeds of about 17,500 miles an hour.

It is estimated that there are 300,000 pieces of space junk ranging from one-centimetre to the size of bowling balls, and that on average one satellite is destroyed each year.

EOS chief executive Dr Ben Greene says that they have invested 80m Australian dollars ($74,6m; £45m) into developing their light-based technology systems, which have become cheaper than the use of radar.

Currently, mostly radar-based systems are being used to track space junk, such as the US Air Force's Space Fence. It can follow as many as 200,000 objects in space.

EOS is one of the largest makers of major optical telescopes in the world. They also operate Australia's Space Research Centre at Mount Stromlo.

Tuesday, August 26, 2014

A sheepdog's 'two rules' for success

The relationship between a shepherd and his sheepdog has always seemed almost magical, but scientists now say it can be explained by two simple rules.

Researchers have used GPS data to reveal the mathematical secrets of how sheepdogs do their job.

The new model helps to explain why one shepherd and a single dog can herd an unruly flock of more than 100 sheep.

It could be used to help develop 'shepherd robots', for controlling crowds or cleaning up an oil spill.

'Start Quote

The dog sees white, fluffy things - if there are gaps between them or the gaps get bigger, it needs to bring them together'

End Quote Dr Andrew King Swansea University

The first rule: The sheepdog learns how to make the sheep come together in a flock. The second rule: Whenever the sheep are in a tightly knit group, the dog pushes them forwards.

Selfish herd

Dr Andrew King of Swansea University helped to design backpacks fitted with highly accurate GPS technology. These trackers were attached to a flock of sheep and a sheepdog.

'What's so interesting about this is how simple the rules are,' Dr King told the BBC.

'At the beginning we had lots of different ideas. We started out looking from a birds eye view, but then we realised we needed to see what the dog sees. It sees white, fluffy things. If there are gaps between them or the gaps get bigger, the dogs needs to bring them together.'

According to Dr King, sheepdogs are making the most of the 'selfish herd theory' to bring the animals close together and move them where they want.

'One of the things that sheep are really good at is responding to a threat by working with their neighbours. It's the selfish herd theory: put something between the threat and you. Individuals try to minimise the chance of anything happening to them, so they move towards the centre of a group.'

A colleague, Dr Daniel Strombom from Uppsala University in Sweden, used the GPS data from the collars to develop computer simulations. This enabled them to develop a mathematical shepherding model.

The algorithm displays the same weaving pattern exhibited by sheepdogs. It helps to solve what has been called the 'the shepherding problem': how one agent can control a large number of unwilling agents.

The research was published in Journal of the Royal Society Interface.

'No surprises'

Biologist Dr King also studies swarm behaviour in other species, such as baboons and fish.

'If you are looking at a shoal of fish, it's really unpredictable. You can't just rock up with a camera. With this research you could get really good fine detail because you could reproduce it.'

The scientists hope that the principle can be applied in many different contexts.

'Perhaps mathematicians and engineers or roboticists could put this in to their modelling. For example, if you want to send out swarms of drones to gather information and bring them all back.'

There may be environmental uses too. 'If you think of oil on top of water that you want to bring together, in theory you could develop a robot using this model that could help do this.'

However, some shepherds are sceptical of the value of the research.

'It confirms something that shepherds know from many years of watching and working with border collies,' said Jane Drinkwater, a shepherd in South Wales.

'Their instinct is to get around the prey, and to draw the prey together as one bunch. The only thing I would say is that they won't always pull the prey towards the handler - they may by instinct head in the opposite direction.'

Global coal 'binge' missed in data

The climate impacts of the world's fossil-fuelled power plants are being underestimated because of poor accounting, say researchers.

Governments would get a truer picture if they included the lifetime emissions of a facility in the year it goes into production

These 'committed emissions' have been growing by 4% a year between 2000 and 2012, the scientists say.

Power plants in China and India alone account for half of this commitment.

At present, UN accounting procedures only include the emissions from coal and gas powered electricity generation in the year in which they occur.

'Start Quote

'We've been hiding things from ourselves'

End Quote Prof Robert Socolow Princeton

According to the authors of the new paper, this method means they are missing a significant part of the picture.

'We are trying to get past a kind of myopia that sets in when people focus exclusively on the emissions of the day,' said one of the authors, Prof Robert Socolow from Princeton.

By taking an expected production life of 40 years, the researchers calculated that the new coal and gas plants built in 2012 would, in total, produce around 19bn tonnes of CO2.

This is significantly more than the 14bn tonnes produced by all the existing fossil fuel plants in the world in the same year.

'We've been hiding things from ourselves,' said Prof Socolow.

A new coal plant every week

What Prof Socolow termed the 'Chinese power plant construction binge', which has occurred since 1995, was a major factor in the story.

Plants in China represent 42% of committed future emissions, while India is responsible for 8%.

That contrasts with the US and Europe, which between them account for 20% of the committed carbon.

'The US and Europe, for the most part, have not paid attention that such large consequences were turning up in the development decisions of the developing world,' said Prof Socolow.

While the share of commitments related to natural gas plants has increased from around 15% in 1980 to 27% in 2012, much of this development is focussed on the Middle East.

Apart from this area, almost the entire developing world is looking to coal as the power plant fuel of choice on the road to industrialisation.

According to the report, all the existing fossil fuel plants in world will contribute 300bn tonnes of CO2 over their lifetimes, putting a significant dent in the remaining carbon budget that would prevent a global temperature rise of 2C, the threshold of dangerous climate change according to scientists.

'Worldwide, we've built more coal-burning power plants in the past decade than in any previous decade, and closures of old plants aren't keeping pace with this expansion,' said co-author Prof Steven Davis at University of California, Irvine.

'Far from solving the climate change problem, we're investing heavily in technologies that make the problem worse,' he said.

The researchers say that their calculation of committed emissions doesn't mean they are unavoidable.

They argue that with properly functioning carbon markets and the development of carbon capture and storage technology (CCS), the scale of the impacts on climate could be reduced.

'The extra piece of this is CCS,' said Prof Socolow.

'There is a tool, it does costs money - but it is one of the ways of having your cake and eating it too.'

The research has been published in the journal Environmental Research Letters.

Follow Matt on Twitter @mattmcgrathbbc.

New concerns over Iceland volcano

The magma from Iceland's Bardarbunga volcano could be moving towards another large volcanic system.

Data recorded by a team from the University of Cambridge suggests that 50 million cubic metres of molten rock has moved in the last 24 hours.

If it continues on a northern trajectory it could feed into the Askja volcanic system, potentially triggering a large eruption.

Prof Bob White said: 'It's headed straight for it.'

But he cautioned that volcanoes were hard to predict.

'It's moving at about 4km a day towards Askja, and if it keeps going it will get there in a few days,' he told BBC News.

'We know there is a lot of molten rock sitting under the ground beneath Askja, which is a major volcanic system. If this molten rock hits that, we know it is likely to trigger it to erupt.

'But who knows, it may just stop. It is still at 5km-depth, and it is possible it could freeze there and not a lot more will happen. That is perfectly plausible.'

The Cambridge seismology group has been monitoring volcanoes in the area since 2006 with more than 70 seismometers.

'Start Quote

It is a huge amount of magma, creating an enormous subterranean channel of molten rock'

End Quote Prof Simon Redfern University of Cambridge

Over the last 10 days, they have detected large numbers of earthquakes, which have been moving north over a distance of about 40km. They are caused as magma flows beneath the ground, cracking the rocks as it moves.

On Tuesday morning the Bardarbunga volcano was hit by a magnitude 5.7 earthquake, the largest since tremors began in the area last week.

The team estimates that about 350 million cubic metres of magma have moved in this period, which is about twice the amount of molten rock that was blasted into the air during Iceland's Eyjafjallajokull eruption in 2010.

Prof Simon Redfern, an earth scientist from the University of Cambridge, said: 'It is a huge amount of magma, creating an enormous subterranean channel of molten rock.'

He said that the dyke - the underground 'plumbing system' that carries the molten rock - could join up with other underground fissures, creating a large network of magma.

Prof White added that several scenarios were possible.

'One is that it erupts under the glacier,' he said.

'That is bad news because this kind of eruption can drive the big ash clouds that can go up 35,000-40,000ft, and that is what happened in 2010 with Eyjafjallajokull.'

However that scenario is looking less likely because the magma is moving beyond the thick ice of the glacier into shallower terrain beyond.

If it erupts in this region, with less ice-cover, it could create 'fire-fountains' - spectacular plumes of lava, which can be dangerous, but carry less ash.

Prof White said: 'The third scenario is that it keeps going north, it keeps feeding molten rock and it hits the Askja system and triggers that - then goodness knows what will happen. It could make a lot of disruptive ash all over Iceland.'

The last time that the Askja volcano had a major eruption was in 1875. The ash-fall caused crops to fail and killed livestock, triggering a wave of migration away from the north east of Iceland.

'Curtain of fire'

Commenting on the team's findings Prof David Rothery, from the Open University, said that while the magma could head for Askja, it may also change its route.

'Magma could be heading along a dyke towards Askja, which last erupted in 1961, or it might bypass it and be injected northwards along a fissure that passes to the east of Askja, where there have been several earthquakes in the past week,' he told BBC News.

'In neither case is an eruption inevitable. Many dykes never reach the surface.

'An eruption along a dyke could be a spectacular affair, beginning as a 'curtain of fire' feeding an expanding lava field. That sort of eruption is most unlikely to produce a column of fine ash that would get high enough to be a hazard to more than a local aviation.

'I would anticipate a bigger problem if an eruption of stored, gas-rich magma were to begin at Bardarbunga itself, but even that would cause major disruption to air travel only if it was powerful enough to reach about 20 km high and if the wind carried the ash southeast over the UK and mainland Europe.'

On Saturday, Iceland raised its level of alert to the aviation industry to red, warning of an imminent eruption, but then lowered it on Sunday to its second-highest level, orange.

Airspace over the site has been closed, but all Icelandic airports currently remain open, authorities say.

The Eyjafjallajokull eruption in April 2010 caused the largest closure of European airspace since World War Two, with losses estimated at between 1.5bn and 2.5bn euros (£1.3bn-2.2bn).

However since the eruption, the Civil Aviation Authority has relaxed its rules to allow planes to fly in areas with a low density of volcanic ash.

Badger cull targets are announced

A target number of badgers to be killed in this year's pilot cull, to tackle tuberculosis in cattle, has been announced.

Authorisation letters for the cull have been issued by Natural England. A minimum of 615 in Gloucestershire and 316 in Somerset need to be killed.

In 2013, 921 badgers were killed in Gloucestershire and 940 in Somerset.

The companies carrying out the cull have not announced when it will start this year.

A maximum number of badgers that can be culled this year has been set at 1,091 in Gloucestershire and 785 in Somerset.

Original population estimates for badgers in Gloucestershire have now been revised by The Department for Environment, Food and Rural Affairs (Defra) to 1,904 in Gloucestershire and 1,876 in Somerset.

The four-year pilot cull aims to kill 70% of the initial population to test how effective, humane and safe a cull can be.

An extension to the cull in 2013 in Gloucestershire was ended early as it had not met its target, and the Somerset pilot failed to meet its target even after a three-week extension.

Government ministers and the National Farmers' Union believe culling badgers will curb TB in cattle. Opponents say shooting the animals is not effective.

Monday, August 25, 2014

Magnetic levitation in 3D advances

Researchers from Harvard University have discovered how to orientate small objects in any direction using magnetic levitation.

Methods to manipulate small objects are crucial to manufacture complex structures such as electronic components in assembly lines.

But few methods exist that deal with fragile and arbitrarily shaped objects.

The researchers rotated delicate objects of varied shapes and sizes without 'touching' them.

The results of their experiments are published in PNAS journal.

Lead author, Dr Anand Bala Subramaniam, from Harvard's Department of Chemistry and Chemical Biology told, BBC News: 'Magnetic levitation in liquids has been used before to separate materials based on their density, but never to manipulate objects.'

Magnetic levitation is commonly referred to as MagLev.

Dr Andrew Steele, who was not part of the study, specialised in magnetism at the University of Oxford during his PhD.

He said: 'The classic way of doing magnetic levitation is using magnets. Take two magnets, or a magnet and a piece of superconductor, which will then have opposing magnetic fields.'

The repelling force lifts the magnetic object against gravity. The method used in the new study is slightly different.

'What they are doing is suspending a non-magnetic object that is embedded in a liquid that is itself magnetic. It's an advanced form of floating.'

The device consisted of a chamber filled with a paramagnetic fluid - a fluid that is attracted to a magnetic field - with magnets at the top and bottom.

The magnets 'pulled' the liquid upwards and downwards, creating a density gradient: the liquid was more compressed in the regions close to the top and bottom lids, and less in the middle of the chamber.

'If you place an object in that chamber, gravity is pulling it down and buoyancy is pushing it up. The object finds a position where it wants to float based on its density compared to that of the liquid around it,' explained Dr Andrew.

The key aspect is that this method does not require the object to be magnetic at all.

'You can levitate almost whatever you want as long as it's lighter than the liquid you are levitating it in.'

The device has potential applications in the automated manufacture of soft objects that try to mimic biological systems.

Dr Bala Subramaniam said: 'If you have a hard gripper coming in and trying to grab a soft object it may deform it and even damage it.

'There really is a need for methods that can manipulate and orient objects without contact, which is what the MagLev does.'

The researchers found that rotating or adding another external magnet to the chamber caused the object to rotate in different directions.

'We tried two different methods to show that MagLev is very versatile to orient objects.

'Sometimes bringing an external magnet is more useful than rotating the whole chamber.'

At the moment, Dr Bala Subramaniam's team has experimented with jelly-like materials, silicon grippers that are commonly used in robot assemblies, and gas bubbles of different shapes and sizes.

But the trials were limited to a single object at a time.

'The next step that we need to take is to put more than one object [in the chamber] and try to assemble them in the liquid. For this, you need a more complex configuration of magnets and control algorithms to bring in an object, orient it, then bring in another object, orient it and attach it to the first.

'The results are a starting point. They will require a little more work for practical applications.'

Dr Bala Subramaniam will be joining the School of Engineering at the University of California, Merced, this Autumn.

World's rarest bird needs new home

The Madagascar pochard, the world's rarest bird, will not be able to thrive without a new wetland home.

This is according to a study revealing that 96% of the chicks are dying at two to three weeks old.

Conservationists say that human activity has driven the birds to one remaining wetland, but that that site has insufficient food for the ducks.

The research is published in the journal Bird Conservation International.

The Wildfowl and Wetlands Trust (WWT), which led the research, estimates that only 25 individual birds now remain in the wild.

Human activity, including deforestation, farming and fishing, has destroyed their habitat to the point that this last population is now restricted to one wetland in north-east Madagascar - a complex of lakes near Bemanevika.

After the rediscovery of the species at this site in 2006, the WWT and its partners, including the Durrell Wildlife Conservation Trust and the Peregrine Fund, set up a conservation breeding programme and began to monitor the wild birds.

Dr Geoff Hilton, head of species research at the WWT, said that with such a small number of birds, keeping a close eye on the population was straightforward.

'We had about 10 or 11 females, [and] we were able to tell that most of those females were laying eggs, and those eggs were hatching,' he told BBC News.

But at the point when the ducklings were two to three weeks old, they would start disappearing.

Too deep to dive

Piecing the evidence together, including samples of food from the bottom of the lake, the researchers realised that the chicks were starving to death.

These diving ducks feed from the bottom of lakes, and this steep crater lake was simply too deep for them.

WWT senior research officer Dr Andrew Bamford, who led the study, said: 'The last refuge of the Madagascar pochard is one of the last unspoilt wetlands in the country, but it's simply not suited to its needs.

'Something similar happened in the UK when the lowland red kite became confined to upland Wales, and in Hawaii, where the last nenes survived only on the upper slopes of volcanoes because introduced predators had occupied their favoured grassland habitats.'

Dr Hilton added: 'What we think we're seeing is a bit of a classic wildlife conservation conundrum.

'The place where the species hangs on at the end is not a particularly good place for them - it's just the place that's been least badly affected by human activities.'

But the researchers say the species could thrive in Madagascar again if the captive-bred ducks can be found a new wetland home.

'We have been very successful in establishing a captive population,' said Dr Hilton.

'And we have recently identified a lake that we think has potential to be restored and become a reintroduction site.

'The main thing we have to do is work with the local people to reintroduce and restore the pochard, but also to restore the lake and help people to get a better livelihood from the lake they live around.'

Follow Victoria on Twitter

Potential comet landing sites chosen

Europe's Rosetta mission, which aims to put a robot on Comet 67P/Churyumov-Gerasimenko, has identified five potential locations for the touchdown.

The choice of sites was driven largely by operational considerations - they are places engineers believe a lander can get down with the least risk.

No-one has attempted to land on a 10-billion-tonne comet before.

The Rosetta probe will despatch its Philae contact robot to 67P's icy surface on 11 November.

The European Space Agency says it will be a one-shot opportunity.

Rosetta and the comet are currently about 400 million km from Earth, making real-time radio control impossible.

Instead, the process will have to be fully automated with commands uploaded several days in advance.

The five sites on the 'longlist' were selected at the end of a special meeting convened in Toulouse, France, this past weekend.

Esa project managers were joined by attendees from the space agencies of France (Cnes) and Germany (DLR), which play key roles in the Philae effort.

Instrument principal investigators on the washing machine-sized robot were also there to argue their preferences, as were the engineers, who could explain the technical possibilities.

A landing site needs to be relatively flat and free from boulders and fissures.

One key requirement has been the need to find places on the comet that experience something of a day/night cycle.

This will give not only a better appreciation of the changing behaviour of 67P under all conditions, but will provide the lander with some important protection - from too much sun, which could lead to overheating, or too little light, which would make it difficult to charge the batteries.

The engineers have also emphasised the need to find locations where Rosetta can deliver Philae at the right altitude and velocity, and maintain a communications link throughout the descent, which is likely to take several hours.

The longlist will be reduced to a leading candidate and perhaps a couple of back-ups in mid-September.

A final go/no-go decision on a target landing site is expected by mid-October.

By then, Rosetta's cameras and other instruments will have returned detailed data on the number one choice.

Comet 67P has very little gravitational attraction - several hundred thousand times weaker than what it would experience at Earth's surface.

For this reason, it will touch down at no more than a walking pace - about 1m/s.

It will use harpoons and ice screws to try to hang on to the comet and avoid bouncing back into space. and follow me on Twitter: @BBCAmos

Sunday, August 24, 2014

Methane vents bubble up off US coast

Researchers say they have found more than 500 bubbling methane vents on the seafloor off the US east coast.

The unexpected discovery indicates there are large volumes of the gas contained in a type of sludgy ice called methane hydrate.

There are concerns that these new seeps could be making a hitherto unnoticed contribution to global warming.

The scientists say there could be about 30,000 of these hidden methane vents worldwide.

Previous surveys along the Atlantic seaboard have shown only three seep areas beyond the edge of the US continental shelf.

The team behind the new findings studied what is termed the continental margin, the region of the ocean floor that stands between the coast and the deep ocean.

In an area between North Carolina and Massachusetts, they have now found at least 570 seeps at varying depths between 50m and 1,700m.

Their findings came as a bit of a surprise.

What is methane hydrate?

  • Methane hydrate is in the form of a 3D ice structure with natural gas locked inside

  • The substance looks like white ice, but it does not behave like it

  • If methane hydrate is either warmed or depressurised, it will break down into water and natural gas

  • The energy content of methane occurring in hydrate form is immense

  • In the Gulf of Mexico, gas hydrate resources have recently been assessed at more than 6,000 trillion cubic feet

Source: US Department of Energy

'It is the first time we have seen this level of seepage outside the Arctic that is not associated with features like oil or gas reservoirs or active tectonic margins,' said Prof Adam Skarke from Mississippi State University, who led the study.

The scientists have observed streams of bubbles but they have not yet sampled the gas within them.

However, they believe there is an abundance of circumstantial evidence pointing to methane.

Most of the seeping vents were located around 500m down, which is just the right temperature and pressure to create a sludgy confection of ice and gas called methane hydrate, or clathrate.

The scientists say that the warming of ocean temperatures might be causing these hydrates to send bubbles of gas drifting through the water column.

They do not appear to be reaching the surface.

'The methane is dissolving into the ocean at depths of hundreds of metres and being oxidised to CO2,' said Prof Skarke.

'But it is important to say we simply don't have any evidence in this paper to suggest that any carbon coming from these seeps is entering the atmosphere.'

This research, though, does highlight the scale of methane that is under the waters.

Estimates suggest that these undersea sediments are one of the largest reservoirs on Earth, and contains around 10 times more carbon than the atmosphere.

Carbon budget revisions

Prof Skarke and his colleagues estimate that worldwide, there may be around 30,000 of the type of seeps they have discovered.

They acknowledge that this is a rough calculation but they believe that it could be significant.

While the vents may not be posing an immediate global warming threat, the sheer number means that our calculations on the potential sources of greenhouse gases may need revising.

The scientists also found abundant life around many of these seeps, but not perhaps as we know it.

The creatures they describe are termed chemosynthetic, meaning they derive energy from chemical reactions and not from the Sun as do photosynthetic organisms.

Others who have collaborated on the search for seeps say these discoveries are important.

'These are significant geochemically, as they and our research teams found perhaps one of the largest seeps yet discovered with very active methane bubbling and large amounts of frozen hydrates,' said Prof Steve Ross, from the University of North Carolina, Wilmington.

'These seeps are also significant biologically, as we have found unique chemosynthetic communities, huge range extensions and increased biodiversity.'

As to the energy potential of these new seeping sources, Prof Skarke is fairly pessimistic.

'There is no evidence to say that these clathrates are related to conventional gas reservoirs, so there is no evidence to say they are a recoverable resource.'

The research has been published in the journal Nature Geoscience.

Follow Matt on Twitter @mattmcgrathbbc.

Iceland lowers aviation risk warning

Two new earthquakes have shaken the Barbardunga volcano in Iceland, which is already under a 'red alert' aviation warning because of fears an eruption.

They are the strongest earthquakes to hit the volcano since seismic activity began on Tuesday.

Authorities said there had not been a major eruption but have closed the airspace in the area as a precaution.

Iceland's Eyjafjallajokull volcano erupted in 2010, producing ash that disrupted air travel across Europe.

The Icelandic Met Office said it recorded earthquakes of magnitude 5.3 and 5 in the early hours of Sunday morning.

It said they were the strongest earthquakes at the Barbardunga volcano since 1996.

Airspace over the site has been closed, but all Icelandic airports currently remain open, authorities say.

Authorities said on Saturday that a small eruption had taken place under the Dyngjujokull ice cap but that there no signs that gases or ashes had broken through the ice.

Geologists reported that about 300 earthquakes had been detected in the area since midnight on Tuesday.

The Eyjafjallajokull eruption in April 2010 caused the largest closure of European airspace since World War Two, with losses estimated at between 1.5bn and 2.5bn euros (£1.3-2.2bn).

Criticism following the strictly enforced shutdown resulted in the UK Civil Aviation Authority relaxing its rules to allow planes to fly in areas with a low density of volcanic ash.

Bardarbunga and Dyngjujokull are part of a large volcano system hidden beneath the 500m-thick (1,600ft) Vatnajokull glacier in central Iceland.

The region, located more than 300km (190 miles) from the capital Reykjavik, has no permanent residents but sits within a national park popular with tourists.

Authorities have previously warned that any eruption could result in flooding north of the glacier.

'Antarctic audit' for marine life

The most complete audit ever assembled of Antarctic sea life is to be published this week.

More than 9,000 species, from single-cell organisms to penguins and whales, are chronicled in the first Antarctic atlas since 1969.

The book will be launched by the Scientific Committee on Antarctic Research at its Open Science Conference in Auckland, New Zealand.

Across 66 chapters, the atlas contains around 100 colour photos and 800 maps.

It is called the Biogeographic Atlas of the Southern Ocean.

'It's been an enormous international effort and will serve as a legacy to the dedicated team of scientists who have contributed to it,' said Dr Huw Griffiths, one of the atlas's authors and editors, from the British Antarctic Survey.

Dr Griffiths said he hoped the atlas would appeal to 'anyone interested in animals living at the end of the Earth'.

All together 147 scientists from 91 different institutions around the world contributed to the work, which has taken four years.

They hope the publication will help inform conservation policy, such as the issue of whether marine protected areas should be established in open swathes of the Southern Ocean.

The data include the distribution of different species, insights into their evolution and genetics, their interaction with the physical environment and the impacts of climate change.

Researchers hope the information can help predict how the habitats and distribution of important species will change in the future.

The book's chief editor, Dr Claude De Broyer from the Royal Belgian Institute of Natural Sciences, said: 'This is the first time that all the records of the unique Antarctic marine biodiversity, from the very beginnings of Antarctic exploration in the days of Captain Cook, have been compiled, analysed and mapped by the scientific community.'

Dr De Broyer described the atlas as 'an accessible database of useful information' for conserving the marine life of the Antarctic.

Saturday, August 23, 2014

Iceland issues volcano red alert

Galileo satellites on wrong orbit

The European Space Agency (Esa) says the latest two satellites for Europe's version of the American GPS satellite navigation system have not gone into the correct orbit.

However, it says the fifth and sixth satellites launched from French Guiana on Friday are under control.

The agency is examining the implications of the anomaly.

The satellites Doresa and Milena went up on a Soyuz rocket after a 24-hour delay because of bad weather.

'Observations taken after the separation of the satellites from the Soyuz VS09 (rocket) for the Galileo Mission show a gap between the orbit achieved and that which was planned,' said manufacturer Arianespace, in a statement.

'They have been placed on a lower orbit than expected. Teams are studying the impact this could have on the satellites,' it added.

Arianespace declined to comment on whether their trajectories could be corrected, the AFP news agency reports.

After years of delay, Galileo is now finally moving towards full deployment.

Esa, which is building the system on behalf of the EU, expects to have a 26-satellite constellation in orbit by 2017.

The EU is investing billions in its sat-nav project.

It believes Galileo will bring significant returns to European economies in the form of new businesses that can exploit precise timing and location data delivered from orbit.

Europe's Galileo system under construction

A project of the European Commission and the European Space Agency

30 satellites are likely to be launched in batches in the coming years

Galileo will work alongside GPS and the Russian Glonass systems

Full system promises real-time positioning down to a metre or less

It should deepen and extend high-value markets already initiated by GPS

Cost to date: 6bn euros (£4.8bn); budget set aside to 2020: 7bn euros

European GDP reliant now on GPS applications: 800bn euros per annum

Source: EC/Esa

MH370 search faces tough next phase

The next phase of the hunt for the missing Malaysia Airlines jet MH370 will be very challenging in places.

Detailed information being gathered about the shape of the ocean floor west of Australia confirms the seabed in some locations to be extremely rugged.

Two vessels - the Fugro Equator and the Zhu Kezhen - are currently mapping an area covering 60,000 sq km.

This survey will guide a metre-by-metre search using towed instruments and submersibles.

This is likely to get under way towards the end of September.

The Australian authorities have warned that this could take a year to complete.

The Dutch-owned Fugro Equator and the Chinese naval vessel Zhu Kezhen are presently assembling a bathymetric (depth) map.

It covers the general location in the southern Indian Ocean where investigators believe MH370 is most likely to have come down.

The map is akin to a broad canvas - a first-ever proper look at a terrain about which there is the slimmest of knowledge.

It is essential work. Without this map, which has a resolution of roughly 25m in the deepest depths, it would not be safe to put down submersibles, as there is a high risk these vehicles would be lost.

'Start Quote

The biggest heave we've had so far is 13m. That's a big wave'

End Quote Paul Kennedy Fugro Survey Pty Ltd

'There are volcanoes down there we've found which were unknown before,' says Paul Kennedy from Fugro Survey Pty Ltd.

'There are all sorts of new features that are appearing,' the company's project director for the MH370 search told BBC News.

The Fugro Equator is equipped with a state-of-the-art multibeam echosounder.

The vast majority of the area it is covering has never been sampled before.

It has recorded depths near to 6,000m. Even the shallow regions are more than 1,000m down.

But it is the craggy nature of the seabed that will prompt extreme caution to be exercised in the next phase of operations.

Fugro has been contracted by the Australian Transport Safety Bureau to conduct this part of the search as well.

It will involve the Equator and another ship, the Fugro Discovery. Both ships will pull a deep-tow instrument very close to the sea floor using a 10,000m armoured fibre-optic cable.

'There are areas that are benign and are going to be fairly straightforward. But then there are some areas that we know are going to be really hard work,' explained Mr Kennedy.

'There are some huge valleys between big mountains, and it's going to be really hard to tow our device through those areas. We can do it; it's just going to take a bit longer.'

Mr Kennedy likens the deep-tow's capabilities to human senses.

Echosounders are its ears; cameras represent its eyes; and a chemical sensor works like a nose.

This nose will 'sniff' for the presence of any jet fuel in the water, down to a few parts per billion in concentration.

Assembling the bathymetric map has been a tough job in itself.

The Equator has had to contend with some terrible winter weather.

'Heave is the vertical displacement of a vessel - that's how you measure the size of the waves,' Mr Kennedy said.

'We record it, and you correct for it when computing the bathymetric depth. The biggest heave we've had so far is 13m. That's a big wave.

'Fortunately, the vessel has anti-roll tanks, which push water from side to side inside the ship with great big pumps, and that helps tremendously.

'To get a clean map of the sea floor, we must know the attitude of the ship very accurately, to 0.02 of a degree.'

The Malaysian plane was lost on 8 March as it flew from Kuala Lumpur to Beijing, carrying 239 people.

Its disappearance has become one the biggest mysteries in aviation history.

The best information investigators have for its whereabouts come for a series of brief satellite communications with the jet during its flight.

The last of these connections suggests MH370 crashed into the water inside the 'high priority' search zone now being surveyed by the Dutch and Chinese vessels. and follow me on Twitter: @BBCAmos

Friday, August 22, 2014

Urban areas are hives for wild bees

A study has found a 'considerable richness' of wild bee species in most types of urban habitats.

French researchers recorded almost a third of the nation's 900 species of wild bees living in towns and cities.

Writing in Plos One, they added that 60 species were also found in very urbanised areas in the city of Lyon.

There is widespread concern that wild bee populations in rural areas are being adversely affected by a number of factors, including pesticides.

'For a bee species to be present in [an urban] habitat, it must be able to find food and nesting substrate,' said co-author Laura Fortel, a researcher from the French National Institute for Agricultural Research (INRA).

'Urban and periurban (the transition between rural and urban) sites can provide high quantities of flowers all year long; they show a high diversity of land cover types and are often warmer than surrounding landscapes.'

She added: 'Also, such habitats are seldom treated with pesticides, which are involved in the decline of bees elsewhere.'

City living

The two-year study recorded the number of bee species caught in traps and nets at 24 locations with varying levels of urbanisation - buildings, roads, industrial areas etc - within the Grand Lyon area.

The team collected 12,872 individual wild bees, and recorded 291 different species.

The findings showed that while the overall abundance of bees declined as the level of urbanisation increased, species richness was at its highest in areas of intermediate (50%) urbanisation.

The team also saw a change in the type of wild bee species that thrived as habitats became more urbanised.

'The structure of the community changed along the urbanisation gradient, with more parasitic species in sites with [an] intermediate proportion of impervious surfaces,' they observed.

'There were also greater numbers of cavity-nesting species and long-tongued species in sites with intermediate or higher proportion of impervious surface.

But they added that their findings suggested that the level of urbanisation had no effect on the occurrence of species regarding body size or social behaviour.

Other studies also showed that urban habitats can support a diverse number of wild bee species. A five-year study in Germany's capital city, Berlin, recorded 262 different species, while two studies of 21 urban gardens in New York City observed 110 species of bees.

Ms Fortel concluded: 'The presence of a diverse array of bee species even in the most urbanised area make these pollinators worthy of being a flagship group to raise the awareness of urban citizens about biodiversity.'

Europe expands Galileo network

Europe has launched the next two satellites in the Galileo network - its version of the American Global Positioning System (GPS).

The spacecraft - model numbers five and six - went up on a Soyuz rocket from French Guiana.

Galileo is now finally moving towards full deployment after years of delay.

The European Space Agency, which is building the system on behalf of the EU, expects to have a 26-satellite constellation in orbit by 2017.

To that end, it has just ordered three big Ariane-5 rockets at a cost of half a billion euros.

Europe's premier launch vehicle can loft four spacecraft at a time, and this should allow for six to eight satellites to be put in space every 12 months from now on.

'Every spacecraft is, after in-orbit commissioning, put into operation, and is broadcasting a navigation signal that is a valid signal for users with a combined Galileo/GPS receiver; and there are already receivers on the market that have this capability. So, you have to see the service as being increased one by one,' explained Esa Galileo project manager, Javier Benedicto.

Friday's Soyuz lift-off occurred on schedule at precisely at 09:27:11 local time (13:27 BST; 14:27 CEST).

The 'instant launch window' was required to get the satellites into just the right part of the sky demanded by the network's multi-plane configuration.

The latest platforms, dubbed 'Doresa' and 'Milena' in a public competition, are somewhat different to their four predecessors, which were used to validate the Galileo technology in orbit.

Formally described as the first Full Operational Capability (FOC) satellites, they have been produced by a new manufacturing consortium, comprising the German outfit OHB System and the UK firm SSTL.

This pair have been contracted to supply the next 20 spacecraft as well.

SSTL's role is to integrate all the Galileo system components inside a satellite.

'It's been a high-volume operation,' said SSTL director John Paffett, 'and we're now turning out a payload every six weeks. By the middle of next year, all our payloads will have shipped to OHB, and it won't be long after that that all the finished satellites will have been handed over to Esa.'

Esa still has to procure at least four more satellites to complete a constellation configuration that includes a number of in-orbit spares.

Didier Faivre, Esa's Galileo programme director, said the agency wanted to assess the first satellites in space before issuing another work order.

'We will have to decide whether we buy exactly the same [spacecraft], which is a consequence if everything works well, or if we have to tune things in terms of technology and performance,' he told BBC News.

Europe's Galileo system under construction

A project of the European Commission and the European Space Agency

30 satellites are likely to be launched in batches in the coming years

Galileo will work alongside GPS and the Russian Glonass systems

Full system promises real-time positioning down to a metre or less

It should deepen and extend high-value markets already initiated by GPS

Cost to date: 6bn euros; budget set aside to 2020: 7bn euros

European GDP reliant now on GPS applications: 800bn euros per annum

Source: EC/Esa

The EU is investing billions in its sat-nav project.

It believes Galileo will bring significant returns to European economies in the form of new businesses that can exploit precise timing and location data delivered from orbit.

GPS already underpins a great swathe of activity, with many uses that are unseen and therefore largely unrecognised, such as the timing signal's widespread role in synchronising telecommunications systems and major financial transactions.

Galileo incorporates next-generation technologies, including more advanced atomic clocks.

For navigation applications, this package should give users quicker, more reliable fixes, enabling them to locate their positions with an error of less than a metre, compared with the current GPS error of several metres.

Of the four pathfinder satellites launched in 2011 and 2012, one is now not working properly.

Engineers are trying to trace the source of an anomaly that prevents this platform from transmitting on two of Galileo's three frequency channels.

And Friday's launch was only approved after experts could satisfy themselves that corresponding systems in the new satellites shared no critical design 'commonalities'.

Galileo is one of several networks to follow GPS. The Russians, the Chinese and the Indians are all at various stages in the development and rollout of their independent constellations.

The proliferation of systems speaks to the ubiquity of satellite navigation now in daily life, but also raises serious concerns that societies may be becoming over-reliant on space-borne timing and location data.

The UK's Royal Academy of Engineering issued a report in 2011 that warned of the possibility of huge economic disruption if these systems became compromised for any reason - such as through an outage caused by a massive solar storm.

Russia's Glonass system was knocked sideways for several hours earlier this year, because of bad commands uploaded to its satellites. Receivers picking up Glonass signals could either not provide location fixes or were providing wildly inaccurate ones.

Proponents of global navigation satellite systems (GNSS) say multiple constellations will provide robustness, but the Academy report argued there was also a need need for alternative technologies.

The UK, for example, is installing a ground-based radio system called eLoran. and follow me on Twitter: @BBCAmos

Thursday, August 21, 2014

Stench of decay turns coral away

Baby corals and fish can smell the difference between good and bad reefs, according to a study based in Fiji.

When offered a choice of two water samples in the lab, the animals turned away from the stench of seaweed that invades depleted reefs, but were drawn to the smell of healthy coral.

It is the first time that coral have been shown to react over long distances to chemical 'smells' in the water.

The findings suggest that controlling seaweed is key to repopulating reefs.

Once a coral reef has decayed and seaweed takes over, stopping fishing in the area may not be enough to bring the coral back.

'If you're setting up a marine protected area to seed recruitment into a degraded habitat, that recruitment may not happen if young fish and coral are not recognizing the degraded area as habitat,' said Dr Danielle Dixson from the Georgia Institute of Technology, the study's first author.

'Start Quote

[We thought] this is so cool, nobody's going to believe it. We better do a lot of replicates.'

End Quote Prof Mark Hay Georgia Instititute of Technology

Surprising ability

Dr Dixson's research, published in the journal Science, made use of three marine protected areas off the coast of Fiji, which contain very healthy coral reefs but are immediately adjacent to heavily fished areas, dominated by seaweed.

'We've got these fished and un-fished areas that are small and immediately adjacent to each other, so it's a nice experimental setting,' said Prof Mark Hay, the study's senior author.

Water from both healthy and weedy areas was taken to Prof Hay's lab, where fish placed in a special chamber were offered a choice between the two.

Very young fish from 15 different species all chose the water from the healthy coral reefs, spending more than 80% of their time on that side of the chamber.

Doing the same sort of test with coral was a ground-breaking experiment, Prof Hay said.

'For fish, people weren't too surprised that it happened, even as babies. They have tails, they have a nose. But for corals... they thought we were nuts.'

The idea was challenging because baby corals are so simple. 'They're kind of like bags of snot,' Prof Hay told the BBC. 'We didn't think it would happen either.'

But sure enough, three species of coral larvae showed exactly the same behaviour, swimming into the better-smelling water by waggling their little hairs or 'cilia'.

'Dani and I were sitting around, smiling at each other and just laughing, going - can you believe this? This is so cool. Nobody's going to believe it. We better do a lot of replicates.'

'Start Quote

If we're going to bring these habitats back, just leaving them alone might not be enough'

End Quote Prof Steve Widdicombe Plymouth Marine Laboratory

The researchers also identified the key ingredients, by mixing things up: if they contaminated water from a healthy reef with the smell of specific seaweeds, the fish would avoid it just as much as water from an abandoned reef.

Similarly, the aroma of certain healthy corals is enough to make bad water attractive.

Breaking the cycle

These results reveal new complexity in the way that coral behave.

Previous work had showed that coral larvae would settle in some places and not others, based on molecular cues. But researchers had only seen this happen over very short distances, when the coral effectively contact a good or bad surface.

'This is the first time that we've seen coral's ability to assess this on a large scale, when they're floating around,' Prof Hay said.

'They can't do much against a current. So what we think is going on is that they're drifting through these different reefs, and if it smells good, they go down.

'It's a very strongly selected behaviour. Over aeons, there's been good reefs and bad reefs and if you settle on the bad ones, you die.'

The discovery also indicates something of a vicious cycle, whereby fish and coral will not settle in an area unless it already contains other, healthy coral giving off the right odours.

The news is not all bad, however. If the seaweed giving off bad smells can be removed, and a previously abandoned area seeded with the most pleasantly perfumed coral, these new insights could help turn things around.

Tackling the seaweed is an important first step, and Prof Hay is working with villagers in Fiji on two strategies.

Certain fish eat these weeds, so he is encouraging the locals to avoid those species when spear-fishing. There is also hope of recruiting villagers to help physically clear the seaweed away, in the months before most coral larvae are looking to settle.

Prof Steve Widdicombe, head of science in Marine Life Support Systems at the Plymouth Marine Laboratory, said the findings had important implications.

'Having the right conditions is important. [These animals] are programmed to look for the places that they're going to be most successful in.

'It was very interesting to see this idea that if we're going to bring these habitats back, just leaving them alone might not be enough. We might have to make some active steps.'

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Warming 'pause' may last until 2025

The hiatus in the rise in global temperatures could last for another 10 years, according to new research.

Scientists have struggled to explain the so-called pause that began in 1999, despite ever increasing levels of CO2 in the atmosphere.

The latest theory says that a naturally occurring 30-year cycle in the Atlantic Ocean is behind the slowdown.

The researchers says this slow-moving current could continue to divert heat into the deep seas for another decade.

However, they caution that global temperatures are likely to increase rapidly when the cycle flips to a warmer phase.

'Start Quote

The Pacific is a symptom of the hiatus but not the ultimate cause. The Atlantic is the driver'

End Quote Prof Ka-Kit Tung University of Washington

According to the Intergovernmental Panel on Climate Change (IPCC), global average temperatures have increased by around 0.05C per decade in the period between 1998 and 2012.

This compares with a decadal average of 0.12 between 1951 and 2012.

More than a dozen theories have been put forward on the cause of this pause in temperature growth that occurred while emissions of carbon dioxide were at record highs.

These ideas include the impact of pollution such as soot particles that have reflected back some of the Sun's heat into space.

Increased volcanic activity since 2000 has also been blamed, as have variations in solar activity.

The most recent perspectives have looked to the oceans as the locations of the missing heat.

Last year a study suggested that a periodic upwelling of cooler waters in the Pacific was limiting the rise.

However this latest work, published in the journal Science, shifts the focus from the Pacific to the Atlantic and Southern oceans.

The team, lead by Prof Kat-Kit Tung from the University of Washington, US, says there is now evidence that a 30-year current alternately warms and cools the world by sinking large amounts of heat beneath these deep waters.

They've used observations from a network of devices called Argo floats that sample the oceans down to 2,000 metres.

Ice age fears

The researchers say that there was another hiatus between 1945 and 1975 due to this current taking down the heat, that led to fears of a new ice age.

From 1976 though, the cycle flipped and contributed to the warming of the world, as more heat stayed on the surface.

But since the year 2000, the heat has been going deeper, and the world's overall temperatures haven't risen beyond the record set in 1998.

'The floats have been very revealing to us,' said Prof Tung.

'I think the consensus at this point is that below 700 metres in the Atlantic and Southern oceans [they are] storing heat and not the Pacific.'

A key element in this new understanding is the saltiness of the water. The waters in the Atlantic current coming up from the tropics are saltier because of evaporation. This sinks more quickly and takes the heat down with it.

Eventually though, the salty water melts enough ice in Arctic waters to lower the saline level, slowing down the current and keeping the heat near the surface.

'Before 2006 the saltiness was increasing, this indicated that the current was speeding up,' said Prof Tung.

'After 2006, this saltiness is diminishing but it's still above the long-term average. Now it is slowly slowing down.

'Once it gets below the long-term average, then it is the next period of rapid warming.'

As well as the data from the Argo floats, Prof Tung has also examined the Central England Temperature record, that dates back over 350 years. He believes that this confirms the regular 70-year cycles of warm and cold spells.

This historic pattern, he says, could extend the current period of pause.

'We probably may have another 10 years, maybe shorter as global warming itself is melting more ice and ice could flood the North Atlantic, but historically we are in the middle of the cycle.'

Rising staircase of warming

Several other researchers in this field acknowledge the Tung analysis is part of a growing body of evidence that suggests the Atlantic has a role in the pause.

Prof Reto Knutti from the ETH Zurich has recently published a review of all the current theories on the hiatus.

'I see the studies as complementary, and they both highlight that natural variability in ocean and atmosphere is important in modifying long term anthropogenic trends,' he said.

'A better understanding of those modes of variability is critical to understand past changes (including differences between models and observations during the hiatus period) as well as predicting the future, in particular in the near term and regionally, where variability dominates the forced changes from greenhouses gases.'

Other scientists say that the Atlantic hypothesis is interesting but a much longer range of observations is needed.

'We really don't have a lot of data,' said Dr Jonathan Robson from the University of Reading, UK.

'So if there is this 60-year oscillation in the ocean, we haven't observed it all, basically we've observed the impact of it. We may have to wait 15-20 years to know what's going on.'

Prof Tung believes that whatever the cause and the length of the pause, we are on a 'rising staircase' when it comes to global temperatures that will become apparent when the Atlantic current switches again.

'At the end we will be on the rising part of the staircase, and the rate of warming there will be very fast, just as fast as the last three decades of the 20th Century, plus we are starting off at a higher plateau. The temperatures and the effects will be more severe.'

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