Testes ‘most distinct human tissue’

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Statue

The testes have been identified as the most distinct type of human tissue by the Royal Institute of Technology in Sweden.

The team have detailed which proteins are active in which tissues of the human body.

It shows the testes needed the most distinct suite of proteins to function.

The Human Protein Atlas has been described as a “really important foundation” for scientific research that could help develop new drugs.

Human DNA contains the instructions for building about 20,000 proteins – the little bits of biological machinery that run our body.

The combination of proteins active in a cell decides its function – a cell for filtering the blood in the kidney works differently to a neuron in the brain.

‘Housekeeping’

Scientists have now pieced together which proteins function where and hope the findings could have important implications for medicine.

“Surprisingly for us, there is altogether very little proteins which are enriched in the different parts of the human body and almost half of the 20,000 genes are coding for proteins which are expressed in all cells and tissues of the body,” Prof Mathias Uhlen, the project leader, said.

These are described as “housekeeping” proteins necessary to keep every cell functioning.

But 999 proteins were significantly more active in testicular tissue than anywhere else in the body.

Testicles Some proteins are more active in testicular tissue than elsewhere in the body

The cerebral cortex of the brain had 318, the liver 172 and smooth muscle zero.

Prof Uhlen told the BBC News website: “If you’re interested in the brain or neurological disorders or even degenerative diseases like Alzheimer’s obviously it is interesting to know which proteins are elevated in the brain.”

He speculated the testes were unique because of the complicated method of producing sperm, which need to have half as much DNA as a normal cell.

“Also there are about 600 proteins which are targets for all the pharmaceutical drugs, so you can say where are these targets located in the human body because that gives you indications about side effects.”

Antibodies

The team used antibodies designed to latch on to different proteins.

They then exposed 32 types of tissue – representing all the major organs and tissues in the body – to the antibodies to see which ones stuck and therefore which proteins were active.

The team aim to develop a “pathology atlas” that will show what goes wrong during disease and which proteins are involved.

Dr Ewan Birney, the associate director of the EMBL-European Bioinformatics Institute, said the project would complement the rapid advances in understanding DNA.

He told the BBC: “It’s looking great – it’s going to be a really important foundational resource on top of the bedrock of the Human Genome Project.

“It is going to accelerate both basic and clinical research. It’s much closer to the action than genomes.

“About half of proteins we’re really head-scratching about what they do… [now there are] proteins we know exist, we know they do something, but now we know where to look.”

He argued the testes had more distinctive proteins because of their focus on producing large numbers of sperm without any errors in their genetic code.

Mutations in a normal cell may eventually lead to cancer. However, a mutation in sperm could stop it being able to fertilise an egg, he said.

Meanwhile, the unique brain proteins may be down to a “sheer logistics problem” involved in operating really long nerve cells stretching across the brain, he argued.

Article source: http://www.bbc.co.uk/news/health-29932395#sa-ns_mchannel=rss&ns_source=PublicRSS20-sa

Brain’s taste secrets uncovered

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The brain has specialist neurons for each of the five taste categories – salty, bitter, sour, sweet and umami – US scientists have discovered.

The study, published in the journal Nature, should settle years of debate on how the brain perceives taste.

The Columbia University team showed the separate taste sensors on the tongue had a matching partner in the brain.

The scientists hope the findings could be used to help reverse the loss of taste sensation in the elderly.

It is a myth that you taste sweet only on the tip of the tongue.

Each of the roughly 8,000 taste buds scattered over the tongue is capable of sensing the full suite of tastes.

But specialised cells within the taste bud are tuned to either salty, bitter, sour, sweet or umami tastes.

When they detect the signal, a message is sent to the brain. Although how the brain deals with the information has been up for discussion.

Accounting for taste

A team at Columbia University engineered mice so that their taste neurons would fluoresce when they were activated.

They then trained their endoscopes on the neurons deep at their base of the brain.

The animals were fed chemicals to trigger either a salty, bitter, sour, sweet or umami response on the tongue and the researchers monitored the change in the brain.

They found a “hard wired” connection between tongue and brain.

Prof Charles Zuker told the BBC News website: “The cells were beautifully tuned to discrete individual taste qualities, so you have a very nice match between the nature of the cells in your tongue and the quality they represent [in the brain].”

It scotches the alternative idea that brain cells respond to multiple tastes.

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Taste in the animal kingdom

Panda

Pandas evolved from carnivorous bears to eat bamboo – they have lost the ability to taste umami, the savoury taste of meat

Cats, from big wild ones to pets, don’t do sweet – they are carnivores so focus on the other tastes

Vampire bats are one of the few species to have reduced umami, sweet and bitter tastes – their diet of blood limits their exposure to other tastes

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Elderly benefit

Prof Zuker said: “In the ageing population, they don’t enjoy eating anymore, you cannot believe how devastating this is.

“We believe that is a reflection of the taste cells in the tongue.”

Stem cells in the tongue produce new taste cells every fortnight. However, this process becomes weaker with age.

“These findings provide an interesting avenue to help deal with this problem because you have a clear understanding of how taste is functioning so you could imagine ways of enhancing that function,” Prof Zuker added.

This could include ways of making the existing cells more responsive so they sent a stronger signal to brain.

However, the findings are unlikely to help devise ways to encourage children to eat their greens.

The five tastes are innate rather than learned, and bitter is the signal that something may be toxic.

Children, of course, love the taste of calories, namely sugar, and the only way to change tastes is with time.

“Give a baby sugar and it smiles, give it quinine and it frowns. But give me tonic water and I like it, I like to be on the edge,” Prof Zuker said.

Article source: http://www.bbc.co.uk/news/health-29912877#sa-ns_mchannel=rss&ns_source=PublicRSS20-sa

Warning of ‘insufficient’ flood cash

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Flooded railway line in DawlishRailway lines in Dawlish, Devon, were damaged by floods this year

Spending on flood protection in England is “insufficient” to maintain defences, the National Audit Office (NAO) has warned.

It said half of the country’s defences were being maintained to a “minimal level”, and were likely to “deteriorate faster”.

The NAO also said spending on them had been cut in real terms between 2010/11 and 2014/15.

The government said it was spending “more than ever before” on resources.

The Environment Agency said it was making “record levels of investment” in flood schemes.

The report said five million properties were at risk of flooding in December 2013.

The NAO said the agency had improved the cost effectiveness of its flood risk spending, but faced “difficult decisions around whether to continue maintaining some flood defences” or whether to let them “lapse”.

Flooding in Moorland, SomersetThe village of Moorland in Somerset was flooded in February

As of August 2014, 1,356 flood defence systems, half of England’s total, were being maintained to a minimal level, it said.

In areas deemed lower priority – typically because they contained fewer homes – the danger of flooding was increased, but the agency had not set out how prioritising flood defences in certain areas would affect the risk elsewhere, the report said.

Labour MP Margaret Hodge, who chairs the Commons public accounts committee, said: “I am deeply concerned that current levels of spending are not enough to maintain flood protection, with five million homes at risk of flooding and people’s livelihoods in jeopardy.”

The government made an extra £270m available after storms last winter led to widespread flooding, with 7,700 homes and 3,200 commercial properties in England affected.

But the NAO said in real terms there was a 6% drop since 2010/11.

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Analysis by Roger Harrabin, environment analyst

Kingsand is hit by a huge waveEngland’s south coast, including Kingsand in Cornwall, was battered by huge waves

Nature doesn’t like man made flood defences. Given time, the waves, tides and rivers would nibble away at our sea walls and embankments – and eventually gobble them up and redistribute them through the oceans.

That fact lies behind today’s complaints over government policy, because in the laudable process of re-organising flood defence funds to protect the most populous areas, cash has been stripped from existing defences protecting more sparsely populated areas.

The government’s many critics – and they are many – say it makes no sense to have built defences but only maintain them at a level that puts the entire investment at risk from a major flood or storm surge. A brick in time saves nine.

Next month the government will brandish details of its six-year plan for new flood defences. But critics fear it won’t solve the maintenance issue.

The clash between spending on maintenance and capital spending is a global political issue. Capital projects make headlines to impress voters and are tidily deliverable.

Maintenance is dull, piecemeal, and burdens the taxpayer for ever. Except in the case of flood defences, there is wide agreement that this is money well spent.

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NAO head Amyas Morse said the Environment Agency had improved how it prioritised spending and achieved value for money.

He added: “However, if we set aside the emergency spending in response to last year’s floods, and give due credit for efficiency improvements, the underlying spending on flood defences has gone down.”

This was challenged by Flooding Minister Dan Rogerson, who said: “The NAO has drawn conclusions on funding based on inappropriate comparisons.

‘On track’

“We have invested £3.2bn in flood management and defences over the course of this parliament which is a real term increase and half a billion [pounds] more than in the previous parliament. This has allowed us to protect 165,000 families and households in vulnerable areas.”

A spokesman for the Environment Agency said: “We are on track to reduce flood risk to 165,000 properties between 2011 and 2015 and we will continue to invest in those activities that contribute most to reduce the risk of flooding per pound of funding we receive.

“Following the 2013 spending review we have a long-term, six-year capital settlement to continue to improve flood risk management infrastructure. This will allow us to make record levels of investment in capital projects and with this investment we aim to reduce flood risk to a further 300,000 properties.”

Shadow environment secretary Maria Eagle said the government had “no plan for dealing with flooding caused by climate change”.

She added: “Ignoring the evidence on climate change has led to the government making the wrong choices.

“It has taken a short-term approach when a long-term one is needed.”

Article source: http://www.bbc.co.uk/news/uk-politics-29902472#sa-ns_mchannel=rss&ns_source=PublicRSS20-sa

Inflatable baby incubator wins award

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Mom incubatorThe incubator’s inventor says it can match the performance of systems 100 times the price

A prototype inflatable incubator for prematurely-born babies has been picked as the international winner of this year’s James Dyson Award.

Mom costs a fraction of the price to make than commonly-used alternatives.

The project’s inventor – Loughborough University graduate James Roberts – said he hoped the final product would be used in the developing world.

One expert said it should be a good stand-in so long as the babies using it were not too premature.

Mr Roberts said that he had begun work on Mom as part of a final year project inspired by a TV documentary.

“I was watching a Panorama programme on BBC about Syrian refugees, and they had a segment about how there are loads of premature kids dying because of the stresses of war and specifically the lack of incubators out there and the infrastructure to support them,” he recalled.

“I thought there has to be a way to solve that.”

He added that the £30,000 award meant that he could continue work on the machine, which he now hopes to bring to market by 2017.

Jaundice lamp

The device is designed to be delivered as flat-packed parts that are assembled at their destination.

Mom prototypeThe electronic components of the prototype Mom are controlled by an Arduino computer

At its heart is a sheet of plastic containing inflatable transparent panels that are blown up manually and then heated by a ceramic element. This wraps around the interior of the unit to keep a newborn warm.

“When it’s opened it won’t collapse in on the child and will maintain its shape,” Mr Roberts stressed.

An Arduino computer is used to keep the temperature stable, control humidification, and manage a phototherapy lamp that can be used to treat jaundice, as well as sound an alarm.

The electronic components are designed to use as little power as possible and can be run off a car battery for more than 24 hours when mains electricity is not available.

The modular design of the kit allows damaged parts to be replaced without compromising the whole unit. And after the child is taken out of the incubator, it can be collapsed and the plastic sheet sterilised so that Mom can be easily transported for re-use elsewhere.

“Normally with incubators it costs loads to get them anywhere because you need huge boxes to put them in, and that can cost a lot to put on a flight,” Mr Roberts said.

“This one can go in a care packages already used for refugee camps.”

Mom incubatorThe incubator can be powered by a car battery for more than a day at a time

He estimated that the current prototype would cost about £250 to manufacture, and suggested it would offer a similar level of performance to modern systems that cost £30,000.

‘Fantastically elegant’

Mom’s design was praised by one of the UK’s leading neonatal experts.

“In resource-poor settings, the cold is one of the biggest killers of babies that are born slightly premature,” said Dr Martin Ward Platt, a consultant paediatrician at Newcastle’s Royal Victoria Infirmary.

“Just being able to maintain a good and stable environment is of enormous importance.

“We mustn’t lose sight of the fact you can achieve a huge amount of that simply by keeping a baby in contact with a mother’s body. But for a variety of reasons, that isn’t always going to be possible, particularly if the mother becomes ill herself.

James Roberts and James DysonMr Roberts received £30,000 as a result of winning the James Dyson Award

“And in a refugee camp, where it may be necessary to separate a baby from her mother, this provides a fantastically elegant and cheap solution.”

Dr Platt added that normal hospital incubators cost so much because they were designed to cope with babies born with as little as a seventh of the normal birth weight, who would need intensive care for weeks or even months – which Mom is not designed for.

But, the doctor said, doing away with some of the “bells and whistles” in order to “do the basics very well” made sense in situations where expensive kit was not available.

However, he was sceptical of Mr Roberts’ suggestion that a version of Mom might end up being stored in ambulances and used in remote parts of the UK to transport prematurely born babies to hospital.

Even so, the inventor suggested that the modular nature of the incubator could make it easy to adapt its parts for different needs.

“I’ve been approached by a few companies who want to work with me on it, but I have to decide what I want to do,” Mr Roberts added.

The runners-up in the competition were:

  • Qolo – an electric chair that can be controlled by the user tilting and twisting their upper body
  • Suncayr – a pen with colour changing ink that can be applied to the skin to let the user know when they should reapply sun cream
  • Bruise – an injury detection suit for disabled athletes

Article source: http://www.bbc.co.uk/news/technology-29900968#sa-ns_mchannel=rss&ns_source=PublicRSS20-sa

Mystery over monster cosmic cloud

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Gas cloudG2 has been stretched out by the gravity of our galaxy’s central black hole

Observations of a cosmic confrontation between a huge gas cloud and the black hole at the centre of our galaxy have sparked debate among astronomers.

Celestial fireworks were thought to be a possibility as the gas was torn apart by the black hole.

But their absence so far has rekindled suggestions that it may not be a pure gas cloud after all.

One study suggests the cloud, named G2, is in fact a pair of stars that have merged into a much bigger one.

This conclusion has been prompted by observations that G2 survived its closest approach to the Milky Way’s black hole, known as Sagittarius A* (Sgr A*).

“A gas cloud would not do that,” said Prof Andrea Ghez, from the University of California, Los Angeles (UCLA), who co-authored the research in Astrophysical Journal Letters.

But other astronomers are not as sure, and suggest that a more compact gas cloud should still fit the data.

KeckProf Ghez and colleagues carried out their observations at the Keck Observatory on Hawaii

Beyond a certain threshold point – the event horizon – nothing can escape the pull of a black hole, not even light itself. But outside that is a swirling mass of material, not unlike water circling a drain.

Astronomers had already seen G2 being stretched out like a string of spaghetti by the black hole’s extreme gravitational field.

Over an extended period of time, it was expected that about half of the cloud would be swallowed up, with the remainder flung out into space by Sgr A*.

The acceleration of the matter in the cloud would set off a shower of X-rays – the much-awaited celestial fireworks – that would help astronomers learn more about our local supermassive black hole.

But Prof Ghez explained that the cloud was “completely unaffected by the black hole; no fireworks”.

Cloaking mechanism

The team has proposed an alternative explanation for G2 based on their detailed study of the cloud with the huge optical and infrared telescopes at the Keck Observatory in Hawaii.

In their view, the object is in fact best explained by a pair of stars – a binary system – that had been orbiting the black hole in tandem. The stars then merged to form an extremely large star cloaked in gas and dust.

Continue reading the main story

Black holes

Artist's impression, supermassive black hole

  • Black holes are incredibly dense objects with gravity strong enough to trap even light
  • A ‘medium’ black hole could have the mass of 1,000 Suns but be no bigger than Earth
  • Supermassive black holes are thought to be at the centre of most large galaxies – including ours

Source: BBC Science

But Dr Stefan Gillessen, who was not involved in the recent study, maintains that the original interpretation of G2 stands. Dr Gillessen led the team that detected the red cloud approaching Sgr A*, reporting their discovery in Nature journal in 2012.

“The observational facts are clear, I guess: There is gas, which shows a beautiful tidal evolution, as witnessed in the radial velocities. And there is dust emission, which appears to be compact,” Dr Gillessen, from the Max Planck Institute for Extraterrestrial Physics in Garching, Germany, told BBC News.

“I personally am sceptical about the new proposed model: While I trust the observations, I don’t think it is very likely that we can catch an object in the transitional stage of merging.”

Prof Ghez and colleagues suggest that the newly formed object will eventually look like the massive young stars that are tightly clustered around the Milky Way’s black hole – the so-called S-stars.

They also propose that the gravitational influence of the black hole could make mergers of binary stars more likely by increasing the eccentricity of their orbits.

Luck of the draw

But Dr Gillessen explained: “I think we are far from excluding any model.”

He added: “My guess is still: it is an unlucky clump of gas on an almost plunge orbit. The new observations show, that it might be more compact by some moderate factor than what we thought.”

Dr Gillessen suggested there was a very low chance – perhaps lower than 10% – that the observations could be explained by a recently merged binary star. And he added that mathematical models of the object as a gas cloud could be tweaked to enable them to match the new data.

He added that the UCLA team did not detect any emission from the surface of the star.

Of the absence of fireworks, he said: “This is factually correct, but no models actually predicted increased accretion in 2014 – that would come later only. So the absence now is not telling much, I fear.

“On the other hand, it was estimated that the shock front of G2 rushing through the ambient gas might be observable. That has not been observed, which in turn means that G2 is more compact, or the ambient gas is thinner than assumed in these calculations.

“But G2 does not need to be as small as a star for that.”

The debate is likely to continue, but in the meantime, astronomers will be keeping their eyes glued on the centre of our galaxy.

Follow Paul on Twitter.

Article source: http://www.bbc.co.uk/news/science-environment-29934458#sa-ns_mchannel=rss&ns_source=PublicRSS20-sa

First Europeans ‘weathered Ice Age’

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Kostenki 14The DNA comes from a man who lived in westernmost Russia some 36,000 years ago

The genetic ancestry of the earliest Europeans survived the ferocious Ice Age that took hold after the continent was initially settled by modern people.

That is the suggestion of a study of DNA from a male hunter who lived in western Russia 36,000 years ago.

His genome is not exactly like those of people who lived in Europe just after the ice sheets melted 10,000 years ago.

But the study suggests the earliest Europeans did contribute their genes to later populations.

Europe was first settled around 40,000 years ago during a time known as the Upper Palaeolithic.

But conditions gradually deteriorated until ice covered much of the European landmass, reaching a peak 27,000 years ago.

The ice melted rapidly after 10,000 years ago, allowing populations from the south to re-populate northern Europe – during a time known as the Mesolithic. But the genetic relationships between pre- and post-Ice Age Europeans have been unclear.

Some researchers have in the past raised the possibility that pioneer populations in Europe could have gone extinct some time during the last Ice Age.

And one recent study looking at the skull features of ancient Europeans found that Upper Palaeolithic people were rather different from populations that lived during the later Mesolithic period.

In the latest study, an international team of researchers sequenced the genome (the genetic “blueprint” for a human) of a man buried in Kostenki, Russia.

They discovered a surprising genetic “unity” running from the first modern humans in Europe, through to later peoples. This, they claim, suggests that a “meta-population” of Palaeolithic hunter-gatherers managed to survive the Ice Age and colonise the landmass of Europe for more than 30,000 years.

“That there was continuity from the earliest Upper Palaeolithic to the Mesolithic, across a major glaciation, is a great insight into the evolutionary processes underlying human success,” said co-author Dr Marta Mirazón Lahr, from Cambridge’s Leverhulme Centre for Human Evolutionary Studies (LCHES).

Early EuropeanThis reconstruction shows an Upper Palaeolithic woman from southern France

“For 30,000 years ice sheets came and went, at one point covering two-thirds of Europe. Old cultures died and new ones emerged – such as the Aurignacian and the Gravettian – over thousands of years, and the hunter-gatherer populations ebbed and flowed.

“But we now know that no new sets of genes are coming in: these changes in survival and cultural kit are overlaid on the same biological background.”

She added: “It is only when famers from the Near East arrived about 8,000 years ago that the structure of the European population changed significantly.”

The arrival of the first farmers transformed the genetic landscape of Europe – to the extent that no modern population is a good match for the Mesolithic Europeans encountered by the farmers as they spread out across the continent.

The farmers carried the signature of a cryptic population which split off very early from all other Eurasians, including early Europeans and East Asians, and survived in some unknown place until some of their descendents invented agriculture in the Middle East – carrying it into Europe after 8,000 years ago.

“This mystery population may have remained small for a very long time, surviving in refugia in areas such as the Zagros Mountains of Iran and Iraq, for example,” said Dr Mirazón Lahr.

“We have no idea at the moment where they were for those first 30,000 years, only that they were in the Middle East by the end of the ice age, when they invented agriculture.”

Intriguingly, the Kostenki man already shows some evidence of mixing with this very old population, which has been dubbed Basal Eurasians. But analysis of the Europeans who emerged from the Ice Age 10,000 years ago show little sign of this ancestral component in their genomes.

Article source: http://www.bbc.co.uk/news/science-environment-29940694#sa-ns_mchannel=rss&ns_source=PublicRSS20-sa

Half of stars are ‘outside galaxies’

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colliding galaxiesCollisions and mergers can strip stars out of galaxies

A new study of the universe’s background light has suggested that as many as half its stars might be hidden in the space between galaxies.

Measurements were made by two cameras sent beyond the atmosphere on a rocket.

After subtracting all the interference from dust and galaxies, the leftover light has ripples in it, which the study’s authors ascribe to lone stars, flung out during galactic collisions.

Other scientists believe it comes from whole galaxies that are very distant.

The new results are published in the journal Science.

Continue reading the main story

Start Quote

Astronomers know this stripping happens, but we’re saying it’s much more prevalent”

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Prof Jamie Bock
Jet Propulsion Laboratory

Prof Jamie Bock from Nasa’s Jet Propulsion Laboratory, one of the report’s authors, described the extragalactic background light (EBL) as “kind of a cosmic glow”.

“It’s very faint – but basically the spaces between the stars and galaxies aren’t dark. And this is the total light made by stars and galaxies during cosmic history,” Prof Bock told the BBC.

Earlier measurements from rockets and satellites had shown that there was more fluctuation in this background than the sum total of known galaxies could explain.

At least two proposals were made to account for the extra light: it might come from very early, distant galaxies that formed when the universe was much younger, or it might come from stray stars outside galactic boundaries.

Prof Bock’s team set out to study the EBL in detail, in terms of its colour and its distribution, to try and settle the debate.

CIBER rocketThe cameras were taken to sub-orbital space on a sounding rocket

Checking it twice

Two rocket flights were used to collect the data, in 2010 and 2012, as part of an experiment dubbed CIBER: the cosmic infrared background experiment.

On each 10-minute flight, a 10m (30ft) sounding rocket travelled briefly beyond the Earth’s atmosphere and two infra-red cameras took wide-angle images of the sky.

Doing the measurements twice allowed the researchers to rule out fluctuations coming from the dust within our own solar system.

“[On the second flight] we’re looking through a completely different patch of the solar system, and we see the same signal,” Prof Bock explained.

“It’s been really nice to have multiple flights, so we can do all these checks.”

Once all the non-background light, such as galaxies themselves, was discarded – “you kind of surgically remove them” from the images, Prof Bock said – the team was left with a clean picture of the EBL.

Continue reading the main story

Start Quote

This is a big question in astronomers’ minds, because we can’t assign all the light we see to galaxies we know”

End Quote
Prof Jo Dunkley
University of Oxford

The brightness and the blueness of the light in that picture, they claim, support the idea that it comes from stars stripped of their galaxies.

“It’s inconsistent with [the light coming from] the very first galaxies, because it would look a lot redder,” Prof Bock said.

The report also says there is so much light in the recordings that there might be just as many stars outside galaxies as inside them.

“Astronomers know this stripping happens, but we’re saying it’s much more prevalent.”

‘Perfectly possible’

Other researchers are less certain of the data’s implications.

Jo Dunkley, a professor of astrophysics at the University of Oxford, said she did not think the evidence for vast numbers of lonely stars was compelling – “though it would obviously be really interesting if it were”.

“This is a big question in astronomers’ minds, because we can’t assign all the light we see to galaxies we know,” Prof Dunkley told BBC News. “So where is all the rest of it coming from?”

She said that the work represented “a really nice measurement” and agreed that the reported background light probably could not have come from the very earliest galaxies – but argued that there is much still to know about those galaxies, and the ones that followed soon after.

“There’s so many galaxies out there, very faint galaxies, very far away, and I don’t we’ve got a full census of those yet.”

zodiacal lightTo measure EBL, things like zodiacal light (caused by dust in our solar system) must first be substracted

Prof Steve Eales, an astronomer at Cardiff University, was also cautious about the findings.

“When you see a result like this, you never say ‘well yes that’s obviously right’,” he said.

Prof Eales said the JPL team’s interpretation – and their conclusion about extragalactic stars – was “perfectly possible” but that corroborating evidence would be needed.

If so many stars exist outside galaxies, he explained, you might expect to find more examples in between the galaxies closer to our own.

“But the problem is, once single stars move away, they’re very hard to see.

“There’s nothing to rule out the possibility but there’s probably no other evidence yet that they exist.”

Prof Bock acknowledged that his findings would probably not meet with universal acclaim.

“We have to hear how other people react to it,” he said.

Follow Jonathan on Twitter

Article source: http://www.bbc.co.uk/news/science-environment-29917082#sa-ns_mchannel=rss&ns_source=PublicRSS20-sa

History beckons for comet mission

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Jonathan Amos, Science correspondent

Jonathan Amos

Science correspondent

Artist's impression of Rosetta and PhilaeA first for space exploration: No probe has previously made a soft touchdown on a comet

All is on course for Wednesday’s ambitious attempt to put a probe on the surface of a comet.

Europe’s Rosetta spacecraft is currently making a long arc around 67P/Churyumov-Gerasimenko.

Shortly after 06:00 GMT, the orbiter will make a sharp turn towards the ice mountain, accelerate, and then eject the Philae robot towards its target.

Separation should occur at about 08:35 GMT. Touchdown is expected roughly seven hours later.

There are a series of major decision points in the run-up to the ejection – what the controllers back here on Earth call Go/No-go decisions.

It is at these moments that the flight team at the European Space Agency’s operations centre in Darmstadt, Germany, will assess progress and choose either to move forward to the next pinch point, or to abort and regroup for a second landing attempt in a couple of weeks’ time.

At each Go/No-go, the controllers will be paying particular attention to the navigation accuracy of Rosetta as it swoops over the comet to deliver the Philae lander.

The critical one, of course, is the final decision point, when the team receives telemetry from Rosetta describing the performance of that earlier sharp turn.

“We will get a radio signal from the spacecraft that will tell us whether or not our last manoeuvre was successful, within the right accuracy,” says Paolo Ferri, the head of operations in Darmstadt.

“It’s a very small piece of information, and we then have very little time to react, because very soon we have to send an instruction to Rosetta, ‘yes, you’re go for separation of the lander, or not’. This critical decision point, with little information and little time, worries me a lot.”

Three spindles driven by a common belt will release Philae from Rosetta with a velocity of 18cm per second.

If for some reason the spindle system fails to operate, a back-up spring mechanism is automatically primed to fire to ensure the robot is booted off come what may.

“The timing is extremely important, and also where we release the lander,” explains flight director Andrea Accomazzo.

“We have to predict the position at that point to within a few tens of metres or we land somewhere else on the comet or we don’t land at all.

“And the velocity of Rosetta – we need to know to a few millimetres per second. These are the two parameters we have to control very, very accurately.

“Once this is done then the lander will fall on to the trajectory we have predicted.”

Artist's impression of separationThe Philae robot is pushed off Rosetta by means of spindles

On separation, mothership and lander will be out of contact because the umbilical cable that has joined them for the past 10 years will have been dropped in the ejection process.

Controllers will have some idea of their relative positions, however, because a range-finder system will have been activated.

But proper radio communication has to wait until after Rosetta has performed another trajectory change – one that takes it away from the comet and on to a path where it can maintain good radio “visibility” to the descending Philae over a longer period of time.

Establishing radio contact two hours after separation is another of those high anxiety moments.

“If we pick up this signal, no matter what happens on the surface, we will have pictures on the descent and we will have measurements during the descent,” says Paolo Ferri.

“Even if then at the touchdown Philae does not survive, we would have had a significant success all through this descent phase.

“So, the reception of the signal by Rosetta from the lander roughly two hours after separation is for me one of the most critical moments, also.”

We should get a couple of “goodbye” shots from Philae looking back towards Rosetta. They will be iconic images for sure, but they have an engineering significance also because they will tell controllers something about the stability and attitude of the robot as it came off the side of Rosetta.

There should be some downward-looking images also, pulled from the Rolis camera system on Philae.

These will show the approaching comet, and, again, they contain important information about where the lander is headed – information that can be allied to maps of the comet to try to find the robot in the event of a failure at touchdown.

That should occur at just after 15:30 GMT, space time. But because of the 510 million km between Earth and 67P, we won’t know the outcome until a radio signal arrives almost 30 minutes later. The minutes around 16:00 GMT are when we should find out whether history has been made.

Landing siteThe targeted landing site is on the head of the 4km-wide rubber duck-shaped comet

Article source: http://www.bbc.co.uk/news/science-environment-29937050#sa-ns_mchannel=rss&ns_source=PublicRSS20-sa

Bats jam rivals’ senses in food race

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A flying Mexican free-tailed batMexican free-tailed bats emit specialised signals which scramble the echolocation of competitors

Bats were “jammed” the moment they were about to hone in on their insect prey, making them miss their target.



Two bats competing for prey and a visual rendering of the jamming call

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Listen to the bat’s jamming sound

The rival that emitted the call was then able to capture and eat the insect for itself.

This is the first time scientists have witnessed this behaviour in one species – the Mexican free-tailed bat – a team reports in Science journal.

When bats swoop in darkness to catch prey, they emit high-pitched sound waves – a process called echolocation – which speeds up as they get closer to their target. This well-known skill is vital for them to hunt for food and to navigate their environment. This new research shows that others can effectively push them off their tracks mid-hunt.

Lead author of the work, Aaron Corcoran from Wake Forest University in North Carolina, was initially studying moths when he heard these bat calls.

“One bat was trying to capture an insect using its echolocation. The second bat was making another sound that looked to me like it might be trying to jam or disrupt the echolocation of the other bat,” said Dr Corcoran.

“Most of the time when another bat was making this jamming call, the bat trying to capture the moth would miss”, he added.

Cloud of Mexican Free-tailed Bats

In order to study this initial observation further, Dr Corcoran had to illuminate the night sky with a spotlight. On it, he attached a camera with which to record bats capturing insects.

He then reconstructed bats’ flight paths to determine their precise position as they emitted sounds. This was done by placing microphones at various locations to measure the time differences between the sounds.

“We can stitch together all of the sounds that each bat makes and produce a map of their flight trajectories,” explained Dr Corcoran.

When these recorded sounds were manually played back to the bats as they were about to catch a moth, it sabotaged their hunt in the same way. Other recorded bat sounds had no impact.



Two bats competing for prey and a visual rendering of the jamming call

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The first bat captures an insect but the second bat’s signal is jammed

The finding was really unexpected, Dr Corcoran told the BBC.

“Nobody has seen anything like this in any other animals which echolocate. It’s not necessarily surprising that they’re competing with each other [for food] but the fact that they’ve evolved this jamming signal is quite new.

“When a bat is just about to capture a moth we know they are susceptible to jamming at that point. When we look at it from an acoustics or physics point of view, the jamming sounds are produced at the right time and made at the right frequency that match the frequency the other bats are using.”

The researchers will now look to establish whether this skill is unique to this one species, the Mexican free-tailed bat.

Foraging bats were attracted to this field location with the ultraviolet light tower seen in the right of the image, and the bat sounds were recorded on two microphone arrays placed below the lightForaging bats were attracted to this field location with the ultraviolet light tower seen in the right of the image, and the bat sounds were recorded on microphones

Prof Kate Jones at University College London, who was not involved with the study, said that it was fascinating that bats “are doing all kinds of crazy things that we don’t know about”.

They operate in the world using sonar sound and it takes new technology to access this entirely different world, she added.

“Technology is opening up our understanding of these deeply cryptic creatures,” the UCL researcher explained.

Prof Jones, who also studies echolocation in bats, said that there was still much to learn about the social calls bats make, and this new study advanced the field.

Head of monitoring at the Bat Conservation Trust, Dr Kate Barlow, also commented that social interaction between bats was difficult to study because of their small size and nocturnal habits.

“This study reveals another way in which bats have learnt to take advantage of their competitors by listening out for their feeding buzzes… Presumably with the intention of then sneaking in and catching [an] insect for themselves. Very sneaky!”

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Article source: http://www.bbc.co.uk/news/science-environment-29931995#sa-ns_mchannel=rss&ns_source=PublicRSS20-sa

‘Ghostly presence’ created in lab

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Ghost experimentThe researchers created an experiment that made some participants feel a ghost was present in the room

Feelings of a ghostly presence – the sense that someone is close-by when no-one is there – lie in the mind, a study has concluded.

Scientists say that they have identified the parts of the brain that are responsible for generating these spooky sensations.

They have also created an experiment that makes some people feel like there is a ghost nearby.

The research is published in the journal Current Biology.

There are many tales of the paranormal, but an often-reported phenomenon is that of the invisible apparition.

Dr Giulio Rognini, from the Swiss Federal Institute of Technology (EPFL), says: “The sensation is very vivid. They feel somebody but they cannot see it. It is always a felt presence.”

He said it was common in those who experience extreme conditions, such as mountaineers and explorers, and people with some neurological conditions, among others.

“What is astonishing is that they frequently report that the movements they are doing or the posture they are assuming at that specific moment is replicated by the presence. So if the patient is sitting, they feel the presence is sitting. If they are standing, the presence is standing, and so on,” he explained.

Ghost experimentSome of the participants asked for the experiments to stop because the sensation was so odd

To investigate, the researchers scanned the brains of 12 people with neurological disorders, who had reported experiencing a ghostly presence.

They found that all of these patients had some kind of damage in the parts of the brain associated with self-awareness, movement and the body’s position in space.

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Our brain possesses several representations of our body in space”

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Dr Giulio Rognini
EPFL

In further tests, the scientists turned to 48 healthy volunteers, who had not previously experienced the paranormal, and devised an experiment to alter the neural signals in these regions of the brain.

They blindfolded the participants, and asked them to manipulate a robot with their hands. As they did this, another robot traced these exact movements on the volunteers’ backs.

When the movements at the front and back of the volunteer’s body took place at exactly the same time, they reported nothing strange.

But when there was a delay between the timing of the movements, one third of the participants reported feeling that there was a ghostly presence in the room, and some reported feeling up to four apparitions were there.

Two of the participants found the sensation so strange, they asked for the experiments to stop.

The researchers say that these strange interactions with the robot are temporarily changing brain function in the regions associated with self-awareness and perception of the body’s position.

The team believes when people sense a ghostly presence, the brain is getting confused: it’s miscalculating the body’s position and identifying it as belonging to someone else.

Dr Rognini said: “Our brain possesses several representations of our body in space.

“Under normal conditions, it is able to assemble a unified self-perception of the self from these representations.

“But when the system malfunctions because of disease – or, in this case, a robot – this can sometimes create a second representation of one’s own body, which is no longer perceived as ‘me’ but as someone else, a ‘presence’.”

The researchers said that their findings could help to better understand neurological conditions such as schizophrenia.

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Article source: http://www.bbc.co.uk/news/science-environment-29939672#sa-ns_mchannel=rss&ns_source=PublicRSS20-sa

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