NASA's Cassini probe has beamed home stunning images of Saturn and Titan, the ringed planet's largest moon.

The new natural-color Cassini photos, which were unveiled Wednesday (Aug. 29), capture the Saturn system as it undergoes a seasonal shift. The ringed planet and its many moons look quite different today than they did when Cassini arrived on the scene eight years ago, researchers said.

"As the seasons have advanced, and spring has come to the north and autumn to the south throughout the Saturn system, the azure blue in the northern winter Saturnian hemisphere that greeted Cassini upon its arrival in 2004 is now fading; and it is now the southern hemisphere, in its approach to winter, that is taking on a bluish hue," Cassini imaging team leader Carolyn Porco, of the Space Science Institute in Boulder, Colo., said in a statement.

"This change is likely due to the reduced intensity of ultraviolet light and the haze it produces in the hemisphere approaching winter, and the increasing intensity of ultraviolet light and haze production in the hemisphere approaching summer," Porco added. [More Spectacular Photos of Saturn by Cassini]

One of the photos showcases Saturn, its rings and Titan, which at 3,200 miles (5,150 kilometers) wide is larger than the planet Mercury. The edge-on ring system forms a thin line directly behind the huge moon while its shadow projects a series of dark bands onto the planet's southern half.

Another photo shows Titan's south polar vortex — an odd mass of swirling gas that Cassini noticed earlier this year — in clear and dramatic detail. The formation of the vortex is likely related to the seasonal changes occurring on Saturn, Titan and its other moons, scientists have said.

The last photo shows a circle of light around Titan, making the haze-shrouded moon look like a dazzling ring floating in the blackness of space. The effect is created by sunlight scattering through the periphery of Titan's thick, nitrogen-dominated atmosphere, researchers said.

Cassini launched in 1997 and has been studying Saturn and its rings and moons since it arrived in orbit around the planet in 2004. Cassini's primary mission ended in 2008, but the probe's activities have been extended twice, most recently through 2017. 

NASA, the European Space Agency and the Italian Space Agency have worked together on the mission over the years.

Follow SPACE.com for the latest in space science and exploration news on Twitter @Spacedotcom and on Facebook.

• Saturn Quiz: How Well Do You Know the Ringed Planet?
• Photos: Saturn's Glorious Rings Up Close
• The Rings and Moons of Saturn

Please follow Science on Twitter and Facebook.

Join the conversation about this story »

It simply takes too much water to grow a steak. In a new report, leading water scientists say the human population would have to switch to an almost entirely vegetarian diet by 2050 to avoid catastrophic global food and water shortages.

"There will not be enough water available … to produce food for the expected 9 billion population in 2050 if we follow current trends," Malin Falkenmark and colleagues at the Stockholm International Water Institute stated in the report. By their estimation, there should be just enough water to go around if humans derive just 5 percent of their calories from animal-based foods by midcentury, instead of the 20 percent of calories that they currently get from meat, eggs and dairy.

It's a simple numbers game: Cattle, for example, consume a shocking 17 times more grain calories than they produce as meat calories. All that lost grain (which humans could have eaten) requires water. "Producing food requires more water than any other human activity — and meat production is very water-intensive," Josh Weinberg, the institute's communications officer, told Life's Little Mysteries.

The fixed amount of water on Earth indicates people must reduce their meat consumption to avoid shortages. But with so many meat lovers around, will people actually do it?

They'll be forced to eat less meat, experts say. But not by government intervention or their own inner moral compasses. For most people, the choice between a juicy, medium-rare sirloin steak and a humble plateful of soybeans won't turn on which one is sucking wells dry in Texas. It will hinge on the contents of their wallets.

Rich food

In fact, meat eating is already on the decline in the United States. It reached its peak in 2007. According to Janet Larsen, director of research at the nonprofit Earth Policy Institute, Americans collectively consumed 55 billion pounds (25 billion kilograms) of meat that year. This year, consumption will total about 52 billion pounds (22 billion kg). Beef eating has dropped off the most.

One driver, Larsen said, is health; another is environmental concerns, because meat production contributes greatly to greenhouse gas emissions and thus global warming. But the primary reason meat-eating has fallen is the rising price of meat, especially beef, Larsen said. And that reflects the increasing price of the corn used to feed livestock.

"Incomes aren't rising nearly as fast as corn prices, and people end up filling their carts with less meat," Larsen told Life's Little Mysteries. She thinks the trend will continue. "We might go back to when Sunday night dinner was [the only time] when you had a chicken on the table."

In the past two years, corn prices have been driven up in the United States by droughts across the Southern Plains — a palpable demonstration that water is the ultimate deciding factor in the availability of meat. A fixed amount of water paired with a growing world population means something has to give (or if not give, at least become a luxury). And that something is meat eating.

"When you look at the absolute numbers of people on the planet and the amount of food that we're producing, you ask the age-old question: How many people can Earth support? We look at the question from the perspective of food-intake levels," Larsen said.

"People in India eat very little meat, so they consume about 200 kilograms [441 pounds] of grain per person each year. At that level of consumption, our total grain harvest could support 10 billion people on the planet. In the U.S., people are eating closer to 800 kilograms [1,768 pounds] of grain, and that's because much of our grain is being consumed indirectly through livestock. At that level, we could only support a world population of closer to 6 billion or less."

Humans stand at 7 billion strong partly because most people consume a fraction of the grain that Americans do. As the population presses upward, placing ever greater demand on the grain supply, fewer people will be able to afford the large quantity of grain that goes into each pound of meat. Wealthy populations will import grain to support their meat-eating, but at great cost.

Beef will probably end up as the priciest meat of all, Larsen said. In fact, although people in China, India and other rapidly modernizing countries are eating more meat, beef production is already leveling off globally, according to Larsen. "I don't think that the world will be able to produce much more beef," she said. Cows just eat too much. 

Ruminating cows

"Not all animal-based foods are created equal," said Gidon Eshel, a statistician at Bard College in upstate New York who studies the energy cost of various agricultural practices. "Certainly beef is a huge contributor to unchecked water consumption that is hard to imagine continuing."

Eshel's research shows that beef has a "conversion efficiency" of just 6 percent: "So if you give a cow 100 calories of feed, it will produce 6 edible beef calories," he said. Chicken and turkey are four times more efficient, and pork falls in between poultry and beef. [How Much Water Is Used to Grow a Hamburger?]

The low conversion efficiency of the cow is partly due to its digestion, which starts in the rumen. "A ruminant supports itself as well as a couple trillion protozoa and fungi and unicellular organisms that also make a living in its rumen," Eshel said. "We humans also have a ridiculous amount of bacteria, but it is unique that for [cows and other ruminants] the bulk of those hitchhikers are involved in digestion — they mostly live in that oxygen-free chamber called the rumen." In this symbiotic relationship, the bacteria break down cell walls in plant matter and extract the useful material, some of which gets offered up to the host cow, and some of which they use for their own metabolism, Eshel said. "Without them, cows would be no more competent at digesting ruffage than we are."

Considering how much grain cows require to satisfy both themselves and their hangers-on, Eshel thinks beef is still pretty cheap. (In the United States, it's cheap enough to contribute to the obesity epidemic, he noted.) This is bound to change, whether the passionate meat lovers of the world like it or not. "I assume the ranks of 'passionate meat eaters' will thin dramatically," he said, "once it is expensive."

Follow Natalie Wolchover on Twitter @nattyover or Life's Little Mysteries @llmysteries. We're also on Facebook & Google+.

• 5 Ways the World Will Change Radically This Century
• Eat the Old: Could Mass Cannibalism Solve a Future Food Shortage?
• When Will Earth Run Out of Food?

Please follow Science on Twitter and Facebook.

Join the conversation about this story »

A neat study that shows us, once again, that the brain remains plastic in adulthood:

“Scientists at University College London have shown that working as a piano tuner may lead to changes in the structure of the memory and navigation areas of the brain. The study, published today in the Journal of Neuroscience, shows that these structural differences correlate with the number of years of experience a piano tuner has accumulated.

The researchers used magnetic resonance imaging (MRI) to examine how the brain structures of 19 professional piano tuners differed from those of 19 controls. The tuners, from across the UK, all tune pianos by ear, without the use of any electronic instruments.

Sundeep Teki from UCL, joint first author of the study, explains: ‘Piano tuning is a unique profession and this motivated us to investigate physical changes in the brain of tuners that may develop over several years of repeated acoustic practice. We already know that musical training can correlate with structural changes, but our group of professionals offered a rare opportunity to examine the ability of the brain to adapt over time to a very specialised form of listening.’

The researchers found highly specific changes in both the grey matter (the nerve cells where information processing takes place) and the white matter (the connections between cells) within a particular part of the brain: the hippocampus. These changes significantly correlated with the number of years that tuners have been performing the task.” Read more here.

I love the idea of the brain “adapt[ing] over time to a very specialized form of listening.” It makes me wonder about the changes that might be induced by other kinds of listening: Do the brains of experienced clinical psychologists show evidence of all the hours they spend listening for emotion in their patients’ voices? Do the brains of doctors reflect the years they have spent listening to heartbeats and to the sound of air in the lungs? Fanciful questions inspired by a serious insight: our brains are shaped by what we repeatedly do.

Please follow Science on Twitter and Facebook.

Join the conversation about this story »

The genome of a recently discovered branch of extinct humans known as the Denisovans that once interbred with us has been sequenced, scientists said today (Aug. 30).

Genetic analysis of the fossil revealed it apparently belonged to a little girl with dark skin, brown hair and brown eyes, researchers said. All in all, the scientists discovered about 100,000 recent changes in our genome that occurred after the split from the Denisovans. A number of these changes influence genes linked with brain function and nervous system development, leading to speculation that we may think differently from the Denisovans. Other changes are linked with the skin, eyes and teeth.

"This research will help [in] determining how it was that modern human populations came to expand dramatically in size as well as cultural complexity, while archaic humans eventually dwindled in numbers and became physically extinct," said researcher Svante Pääbo at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.

Future research may turn up other groups of extinct humans in Asia "in addition to Neanderthals and Denisovans," Pääbo told LiveScience.

Although our species comprises the only humans left alive, our planet was once home to a variety of other human species. The Neanderthals were apparently our closest relatives, and the last of the other human lineages to vanish. [10 Mysteries of the First Humans]

However, scientists recently revealed another group of extinct humans once lived at the same time as ours. DNA from fossils unearthed in Denisova Cave in southern Siberia in 2008 revealed a lineage unlike us and closely related to Neanderthals. The precise age of the Denisovan material remains uncertain — anywhere from 30,000 to 80,000 years of age.

"The Denisovan genome is particularly close to my heart, because it was the first time that a new group of extinct humans was discovered and defined just from DNA sequence evidence and not from the morphology of bones," Pääbo said.

Denisovan genes unzipped

Now, based on only a tiny sample of genetic material from a finger bone, scientists have sequenced the complete genome of the Denisovans (pronounced deh-NEESE-so-vans), as they are now called.

To make the most of what little genetic material they had, the researchers developed a technique that unzipped the double strands of DNA in the bone, doubling the amount of DNA they could analyze. This enabled them to sequence each position in the genome about 30 times over, generating an extremely thorough genome sequence. [See Photos of Denisovan Fossils]

"We have very few errors in the sequences, even less errors than we often have when you sequence a person today," Pääbo said. "With just a few technical reservations, there is actually today then no difference in what we can learn genetically about a person that lived 50,000 years ago and from a person today, provided that we have well-enough preserved bones."

Comparing the Denisovan genome with ours confirmed past research suggesting the extinct lineage once interbred with ours and lived in a vast range from Siberia to Southeast Asia. The Denisovans share more genes with people from Papua New Guinea than any other modern population studied.

In addition, more Denisovan genetic variants were found in Asia and South America than in European populations. However, this likely reflects interbreeding between modern humans and the Denisovans' close relatives, the Neanderthals, rather than direct interbreeding with the Denisovans, researchers said.

Denisovans began to diverge from modern humans in terms of DNA sequences about 800,000 years ago. Among the genetic differences between Denisovans and modern humans are likely changes that "are essential for what made modern human history possible, the very rapid development of human technology and culture that allowed our species to become so numerous, spread around the whole world, and actually dominate large parts of the biosphere," Pääbo said.

Eight of these genetic changes have to do with brain function and brain development, "the connectivity in the brain of synapses between nerve cells function, and some of them have to do with genes that, for example, can cause autism when these genes are mutated," Pääbo added.

What makes humans special?

It makes a lot of sense to speculate that what makes us special in the world relative to the Denisovans and Neanderthals "is about connectivity in the brain," Pääbo said. "Neanderthals had just as large brains as modern humans had — relative to body size, they even had a bit larger brains. Yet there is, of course, something special in my mind that happens with modern humans. It's sort of this extremely rapid technological cultural development that comes, large societal systems, and so on. So it makes sense that, well, what pops up is sort of connectivity in the brain."

The fact that differences are seen between modern humans and Denisovans in terms of autism-linked genes is especially interesting, because whole books have been written "suggesting that autism may affect sort of a trait in human cognition that is also crucial for modern humans, for how we put ourselves in the shoes of others, manipulate others, lie, develop politics and big societies and so on," Pääbo said.

The genetic diversity suggested by this Denisovan sample was apparently quite low. This was probably not due to inbreeding, the researchers say — rather, their vast range suggests their population was initially quite small but grew quickly, without time for genetic diversity to increase as well.

"If future research of the Neanderthal genome shows that their population size changed over time in similar ways, it may well be that a single population expanding out of Africa gave rise to both the Denisovans and the Neanderthals," Pääbo said.

Intriguingly, comparing the X chromosome, which is passed down by females, to the rest of the genome, which is passed down equally in males and females, revealed "there is substantially less Denisovan genetic material in New Guinea on the X chromosome than there is on the rest of the genome,"researcher David Reich at Harvard Medical School in Boston told LiveScience.

One possible explanation "is that the Denisovan gene flow into modern humans was mediated primarily by male Denisovans mixing with female modern humans," Reich said. "Another possible explanation is that actually there was natural selection to remove genetic material on the X chromosome that came from Denisovans once that entered the modern human population, perhaps because it caused problems for the people who carried it."

These current Denisovan findings have allowed the researchers to re-evaluate past analysis of the Neanderthal genome. They discovered modern humans in the eastern parts of Eurasia and Native Americans actually carry more Neanderthal genetic material than people in Europe, "even though the Neanderthals mostly lived in Europe, which is really, really interesting," Reich said.

The researchers would now like to upgrade the Neanderthal genome to the quality seen with the Denisovan genome. The genetic techniques they used could also be employed in forensic investigations, and in analyzing other fossil DNA, said researcher Matthias Meyer, also at the Max Planck Institute for Evolutionary Anthropology.

The scientists detailed their findings online today in the journal Science.

• In Photos: Uncovering a New Human Species
• Top 10 Things that Make Humans Special
• Image Gallery: Our Closest Human Ancestor

Please follow Science on Twitter and Facebook.

Join the conversation about this story »

Using a mobile phone, tablet or laptop before going to bed leads to sleep troubles according to new research. It’s high time people switch off in order to feel switched.

Researchers at the Lighting Research Centre, which is part of New York’s Rensselaer Polytechnic Institute, have discovered that two or more hours of exposure to backlit devices, such as a smartphone or tablet, suppresses melatonin.

This suppression can lead to trouble sleeping at night, especially in teenagers.

Mariana Figueiro, director of the LRC’s Light and Health Program, who led the team on this piece of research, said: “Our study shows that a two-hour exposure to light from self-luminous electronic displays can suppress melatonin by about 22 per cent.

“Stimulating the human circadian system to this level may affect sleep in those using the devices prior to bedtime.”

Consequently she recommends dimming the brightness on backlit devices to minimize melatonin suppression. But other similar pieces of research go a step further and urge people to have a total break from all devices for several hours before going to sleep.

However, most people I know cannot resist checking their emails, social networks and news feeds throughout the evening.

At the end of last year car company Volkswagen agreed to turn off email to workers with Blackberry devices, in a bid to help with their employees’ work-life balance.

The business agreed to only push emails to German staff 30 minutes before they are due to start work and stop them 30 minutes after they are due to finish work.

The business agreed to only push emails to German staff 30 minutes before they are due to start work and stop them 30 minutes after they are due to finish work.

While I am not sure this is practical for most companies, which operate globally and around the clock, or even necessary, it is up to us as individuals to learn from comprehensive research and amend our behavior accordingly.

For instance, how many people do you know still use an alarm clock? Most people now tend to rely upon their phones, iPods or tablet devices to wake them up.

While it makes sense to make use of the increasing number of shiny devices we have cluttering up our bedside table, this simple act of setting your mobile phone alarm each night often leads to a game being played, a work email being checked or a tweet being posted simply by the device being in your hands.

The return of the good old fashioned alarm clock, combined with a decent amount of discipline, in a bid to let ourselves actually get some proper rest before the whole digital cycle begins again, is what’s necessary to preserve our health in a world which never seems to switch off.

Please follow Science on Twitter and Facebook.

Join the conversation about this story »

Around one in 100 children in the UK could be a psychopath, research suggests.

Displaying similar characterists to the protagonist in the novel We Need To Talk About Kevin, they are liable to lie, cheat, manipulate and commit acts of remorseless cruelty.

Appealing to their sense of fair play and conscience is a waste of time because they lack empathy.

So too are standard punishments such as "time out" which involves brief periods of isolation such as sitting in a corner or on a "naughty chair".

Psychologists are only now starting to recognise that psychopathic children, described as callous-unemotional (CU), form a distinct sub-group.

Unlike most children who display anti-social behaviour, they are not primarily products of bad parenting, according to Professor Essi Viding from University College London.

Her group has carried out twin studies which suggest that psychopathic traits in children are largely genetic.

"For the group which has callous-unemotional traits, there's a strong genetic vulnerability," said Prof Viding.

"This does not mean these children are born anti-social or are destined to become anti-social. But in the same way that some of us are more susceptible to heart disease, these children are people who are more vulnerable to environmental influences that trigger the anti-social outcome."

For other children with conduct problems, a "dose relationship" could be seen with bad parenting, she said. The worse the parents were, the more these children were likely to be anti-social. But this was not the case for children with psychopathic tendencies.

Prof Viding, who will give a talk at the British Science Festival next week, said between a quarter and half of children with conduct problems may fall into the CU category. That amounts to slightly less than 1% of all children.

She told how she applied her own "Kevin test" to her one-and-a-half-year-old daughter. Knowing that emotions are strongly contagious in most small children, Prof Viding pretended to cry profusely.

"I was very relieved when my daughter promptly burst into tears," she said. "I'm not saying that a child who wouldn't start crying at that point is then diagnostic of being a psychopath, but I think that's one fairly crude way to see how your child reacts emotionally."

Usually parents become all-too-painfully aware of psychopathic tendencies in their children over a long period of time, she said.

"The kinds of features that parents report are cruelty to animals, cruelty to younger siblings and lying and not having any remorse or concern about getting caught," Prof Viding said.

Oddly there is some evidence, albeit tentative, that psychopathic children respond to "warm parenting". This might mean giving the children what they want in return for good behaviour, even if this felt a little uncomfortable.

"We may need to appeal to their selfish motives," said the professor.

The British Science Festival opens at the University of Aberdeen next Tuesday.

Please follow Science on Twitter and Facebook.

Join the conversation about this story »

A blue moon will grace the night sky tonight (Aug. 31), giving skywatchers their last chance to observe this celestial phenomenon for nearly three years.

The moon will wax to its full phase at 9:58 a.m. EDT (1358 GMT) today, bringing August's full moon count to two (the first one occurred Aug. 1). Two full moons won't rise in a single month again until July 2015.

But don't expect tonight's full moon to actually appear blue, unless you're peering through a thick haze of volcanic ash or forest fire smoke. "Blue moon" is not a reference to the satellite's observed color.

The term has long been used to describe rare or absurd happenings. And farmers once employed it to denote the third full moon in a season — spring, summer, autumn or winter — that has four full moons instead of the usual three. [Photos: The Blue Moon and Full Moons of 2012]

This somewhat obscure and complicated definition, in fact, is found in the 1937 edition of the "Maine Farmers' Almanac." But in 1946, a writer for "Sky and Telescope" magazine misinterpreted it, declaring a blue moon to be the second full moon in a month with two of them.

Widespread adoption of the new (and incorrect) definition apparently began in 1980, after the popular radio program "StarDate" used it during a show.

Blue moons  occur because lunar months are not synched up perfectly with our calendar months. It takes the moon 29.5 days to orbit Earth, during which time we see the satellite go through all of its phases. But every calendar month (except February) has 30 or 31 days, so two full moons occasionally get squeezed into a single month.

Though the phrase "once in a blue moon" suggests the phenomenon is exceedingly rare, that's not quite the case. On average, blue moons come around once every 2.7 years, making them more common than the Summer Olympics, or a presidential election in the United States.

Some years even boast two blue moons. This last happened in 1999, and it will occur again in 2018.

Tonight's blue moon also happens to fall on the day of late astronaut Neil Armstrong's memorial service. Armstrong, who on July 20, 1969 became the first person to set foot on the moon, died Aug. 25 following complications from heart surgery.

So stargazers may want to keep Armstrong's "one small step" in mind as they gaze up tonight.

"For those who may ask what they can do to honor Neil, we have a simple request," Armstrong's family wrote in a statement shortly after his death. "Honor his example of service, accomplishment and modesty, and the next time you walk outside on a clear night and see the moon smiling down at you, think of Neil Armstrong and give him a wink."

If you snap any good photos of Friday's full moon and would like them to be considered for a future story or gallery, please send them to SPACE.com assistant managing editor Clara Moskowitz at cmoskowitz@space.com, or managing editor Tariq Malik at tmalik@space.com.

Follow SPACE.com senior writer Mike Wall on Twitter @michaeldwall or SPACE.com @Spacedotcom. We're also on Facebook and Google+.

• Will The Blue Moon Really Be Blue? | Video
• Moon Master: An Easy Quiz for Lunatics
• Full Moon: Why Does It Happen? How Does It Affect Us? | Video

Please follow Science on Twitter and Facebook.

Join the conversation about this story »

The world's biggest offshore windfarm could be built off the northern Scottish coast, after a scheme with enough capacity to power 40% of Scottish households was submitted for planning permission.

The £4.5bn complex would have 339 turbines covering 300 square kilometres off Caithness, making it 50% bigger than the giant London Array scheme off Kent. It is expected to be the first in a series of deep water schemes under "Round 3" licensing.

The renewable industry has hailed it as a watershed moment but warned these new deep water farms might only be fully realised if the government provides policy stability by pushing through its proposed Energy Bill.

The 1.5-gigawatt farm is being developed by Moray Offshore Renewables, a joint venture between Spanish oil company Repsol, and an arm of Portuguese power group EDP, which has recently become partly owned by China's state-owned Three Gorges Corporation.

It has already attracted controversy because it is opposed by American billionaire Donald Trump, who says the 200-metre-high turbines will spoil the view from his planned new golf course.

Dan Finch, project director for the scheme due to come on stream in 2018, said working more than 12 miles from shore allowed it to take advantage of the excellent wind resource in the outer Moray Firth.

"We estimate that the project will be capable of supplying the electricity needs of 800,000 to 1m households ... Each year this development could save between 3.5m and 4.5m tonnes of carbon dioxide compared with coal fired generation, and between 1.5m and 2m tonnes of carbon dioxide compared with gas fired generation," he said.

The industry body, RenewableUK, said a further 4.5 gigawatts of offshore wind schemes should follow into the planning process this year with a total of 18 gigawatts expected to become operational over the next eight years.

But Maria McCaffery, RenewableUK's chief executive, emphasised that this progress could only be achieved if the policy certainty laid out in the upcoming Energy Bill was achieved.

"We're marking a watershed moment as Round Three starts to become a reality with this planning application. It's the first of many coming forward. As well as delivering secure supplies of low carbon electricity to British homes and businesses, our global leadership role in offshore wind can provide tens of thousands of jobs across the country, building and maintaining these turbines."

The Moray Firth wind farm, which will be given significant subsidies, compares with the 1-gigawatt at the London Array, which is currently in the construction phase, and compares with the largest British coal-fired plant, Drax in northern Yorkshire of 4 gigawatts, and the planned new EDF nuclear reactors at Hinkley Point in Somerset with a combined output of 3.2 gigawatts and a bill of at least £10bn.

China Three Gorges Corporation acquired a 21% holding from the cash-strapped Portuguese government in Energias de Portugal, EDP, for €2.69bn (£2.13bn). The Beijing-based energy company was responsible for construction of the also controversial Three Gorges Dam-project, the world largest hydroelectric power plant, that went into operation in 2008.

This article originally appeared on guardian.co.uk

Please follow Science on Twitter and Facebook.

Join the conversation about this story »

• Bond is supremely confident. This makes him sexy. It also makes him great at his job; being overconfident often gives better results than being objective and rational. (We'd all be better off moderately overconfident.)Neither men or women prefer modest guys. Bond has the personality of a trained man of action: SWAT team members differed from the average person by being extremely confident ("self-deceptive enhancement"), more emotionally stable and more resilient.

• 007 is almost always calm. (Maybe that's due to all the sex.) Even when people are trying to kill him he's calm. This is sexy. Bond doesn't move unnecessarily. You never see his knee bouncing or hands fidgeting. He speaks slowly and deliberately and is rarely rushed. These are all very charismatic qualities. He has the unflinching eye contact of a predator -- and this increases the chance women will fall in love with him. 007 doesn't gush over girls and show his feelings. He keeps them guessing and uncertainty increases attraction. Bond doesn't smile much and this too makes him sexy because happiness isn't alluring in men. His body language is commanding and he's not afraid to take up space, which is very masculine and appealing. 007 doesn't ramble on and this too issmooth. Bond never slouches. Good posture increases confidence, feelings of power and makes you physically tougher. (Which works out well when you want to look classy in your tuxedo while battling machete wielding evil minions.)

Keep reading at Barking Up The Wrong Tree >

Please follow Science on Twitter and Facebook.

Join the conversation about this story »

As extraterrestrial journeys go, it is not the most imposing challenge that science has faced. Yet the quarter-mile journey on which the Martian rover Curiosity embarked last week is being watched with breathless attention by planetary experts.

The $2.5bn vehicle, the most sophisticated machine to visit another world, was sent to the Red Planet to provide data that could show Mars is, or was, capable of supporting life. This task will require the use of a battery of instruments – lasers to zap rocks, neutron beams to analyse soil and drills to break up samples – which will be put through their paces on this, the Nasa craft's first test drive.

Hence the tension at the Curiosity team's headquarters at the Jet Propulsion Laboratory in Pasadena, California. A failure of a key device on the car-sized rover's jaunt through the red desert of Gale Crater, its landing site, could have devastating consequences, they acknowledge.

"I feel the burden of two and a half billion dollars," geologist John Grotzinger, leader of the 400-strong science team that runs Curiosity, told the journal Nature. "I feel the burden of the future of Mars exploration."

Certainly, much is expected from the rover following its successful landing after being lowered to the Martian surface from a giant rocket-powered device called a sky crane on 6 August. Planetary exploration is now under severe budgetary stress in the US, the nation that has pioneered the field, and there are no detailed plans for future major missions. Hence the care being taken with Curiosity. When it comes to Martian exploration, this may be science's only opportunity for a decade.

Certainly the Curiosity team is taking no chances in directing the craft on its way to Glenelg, the name given to its first target destination. This trip will take several weeks as the six-wheeled vehicle trundles, with infinite care, over the greyish-ochre soil of Mars. "This drive really begins our journey toward the first major destination and it's nice to see some Martian soil on our wheels," said mission manager Arthur Amador. The drive had proceeded beautifully, he said, "just as our rover planners designed it".

Glenelg is considered important because three types of surface material meet there and mission scientists hope to compare these rocks, using the rover's drill to investigate interesting-looking pebbles and boulders. A laser will vaporise slivers of rocks and analyse their chemical composition. A robot arm will pulverise pieces of stone while the rover's Sample Analysis of Mars (Sam) instrument has an oven in which soil and rock samples will be baked and tested for the presence of organic carbon.

"We have already tested quite a few instruments, including all 17 cameras on Curiosity," deputy project scientist Ashwin Vasavada said. "However, the robot arm will be given a full test, as will the craft's different drive modes."

For the next two years or longer, Curiosity will use its instruments to carry out a chemical survey of the interior of Gale crater, a mission which it is hoped will show, once and for all, that the soil of Mars possesses organic materials – including amino acids and sugars, the building blocks of life – that could support living organisms.

"We will carry out a detailed chemical survey of all the different geological layers of Mars and so create an environmental history of the planet," said Vasavada. "That will tell us what era most likely supported life during Mars's history. From that, and from our other surveys of the planet, we will be able to pinpoint the most promising place to find life, or evidence of past life, on Mars."

It will be a tremendous achievement and testimony to the JPL scientists who designed and built Curiosity. But it should be noted that the robot rover will not demonstrate that life exists on Mars. It will merely reveal, at best, that the planet is capable of providing a home for alien lifeforms and will suggest regions to which future missions could be directed. These will then be fitted with the best available instruments to detect life.

Unfortunately, at present Nasa has only limited plans to return to the Red Planet. One modest $425m project, InSight, to be launched in 2016 to study Martian geology, has been approved, though it will have little bearing on the hunt for life there. Apart from that, there is nothing in the pipeline. All other Mars missions have been cancelled as Nasa has struggled with a limited budget and the soaring costs for other projects.

The US is not the only space power capable of reaching Mars, however, and ExoMars – a former joint project backed by Nasa and the European Space Agency – is still scheduled for launch in 2018, even though the US agency pulled out of its involvement last year. "ExoMars is still going ahead," insisted Dr Ralph Cordey, head of science for Astrium UK, which is building the rover that will form the main part of the ExoMars mission. "However, instead of co-operating with Nasa we will go ahead with the Russians."

ExoMars will be smaller than Curiosity but will have one key additional instrument. It will be fitted with a drill capable of probing two metres down into the Martian soil. And that could be crucial. Mars's atmosphere is thin and its surface is bombarded with deadly radiation. Most scientists believe that, if life does exist there, it will be in the form of simple, bacteria-like organisms growing deep underground. ExoMars might just be able to dig some out.

A note of caution should be sounded, however. Europe's new partner on the route to Mars, Russia, has a miserable track record in trying to land craft on the Red Planet. It has 16 failures and only two complete successes to its credit. Yet it will be Russia's task to design and build the lander that will put the ExoMars rover safely on the Martian surface. The omens are not encouraging.

And even if ExoMars reaches its target safely and finds promising material, the hunt for Martian life will be far from over. "The only way we can be sure we have found life on Mars is to bring samples back to Earth, and that will be a very complex mission," said Cordey. "Various proposals for projects have been put forward, but I think it would have to be an international affair, a joint US-European mission most probably, and that would take a long time to set up. I really don't see one being launched until the end of the next decade."

Finding life on Mars may take another 20 years, in other words. The search for ET is proving to be a lengthy one. Of course, the Red Planet is not the only destination in the solar system that could support primitive lifeforms. Several moons of Jupiter and Saturn offer real hopes. In each case, however, missions to these worlds are unlikely to produce results in the next 20 to 30 years, leaving scientists to look further afield, a point stressed by Dr Giovanna Tinetti, of University College London.

She is one of a team of scientists backing a proposed European Space Agency mission called Echo, the Exoplanet Characterisation Observatory. "Instead of studying planets inside our own solar system, we will study those in orbit around other stars," she said. "The light from these stars will pass through their planets' atmospheres and will allow us to study their composition. The presence of reactive gases like oxygen and methane together would indicate that living beings existed on those worlds and were producing these gases. The techniques involved are tricky but the science required has made enormous strides in recent years.

"I wouldn't have thought it possible a decade ago but I would now say it was an evens bet that we detect the presence of life outside our solar system before we find life inside it."

Additional reporting by Geraint Jones

This article originally appeared on guardian.co.uk

Please follow Science on Twitter and Facebook.

Join the conversation about this story »

Off Argentina's coast, the birds have trained themselves to swoop down on the endangered mammals to feast on their blubber when they surface for air.

The waters off Argentina's Chubut province have historically been a prime breeding spot for endangered Southern right whales. But now the gentle, bus-sized mammals are being threatened by a savvy new predator: Ravenous seagulls that swoop down when the whales surface to breathe, tearing and pecking away at their flesh for an easy meal. The attacks have become such a problem that local officials are declaring "open season" on the gulls. Here, a concise guide to this unusual battle:

What's going on exactly?
"The macabre torment of the whales sounds like a punishment from vengeful gods in a Greek myth or the plot of an Edgar Allan Poe story," says Tim Wall at Discovery. About eight years ago, the gull population near the coastal city of Puerto Madryn began to explode, and some of the birds figured out that the whales provided an accessible, rich source of meat. The gulls wait patiently for a whale to breathe, "then tear holes in the whale's flesh and rip off pieces of skin and blubber." 

How problematic are the birds?
The attacks are causing the whales to change their natural behavior, making them increasingly hesitant to surface. They used to leap out of the water in dramatic displays; now, they simply skim the surface just quickly enough to catch a breath and retreat back to deeper waters. "It really worries us because the damage they're doing to the whales is multiplying, especially to infant whales that are born in these waters," says Marcelo Bertellotti of the National Patagonia Center, a government-sponsored conservation group. Experts also fear that the birds could affect the local tourism industry, changing whale-watching from "a magical experience to something from a horror movie," says Australia's Sky News.

Why are there so many gulls?
Human-made garbage. Open air trash heaps near coastal cities "have fueled a massive population boom in seagulls" by providing a huge new food source, says Discovery's Wall. Compounding the problem are fishermen who throw used fish parts — which seagulls eat — back into the ocean.

So now people are going to kill all the seagulls?
Not all of them. The tentative plan is for police to go out on motorboats to selectively shoot at gulls only when they're attacking the whales. Officials hope that this will eliminate the portion of the bird population that has been raised to feast on whale flesh. After the gulls are shot, however, their bodies must be quickly gathered to keep other marine life from swallowing them and their ammunition, which could cause further damage to the marine ecosystem. Some environmentalists, of course, vehemently oppose the plan, and are proposing alternatives, such as closing nearby garbage dumps and prohibiting fishermen from discarding their fish scraps in the ocean. 

Please follow Science on Twitter and Facebook.

Join the conversation about this story »

Why do humans live so long? The African naked mole rat might have the answer, reports Steve Jones.

September already, and the start of term looms near. In the first lecture of my genetics course, I tell the audience to look at the person to their left, and to their right, and point out that two out of each three will die for reasons connected to the genes they carry. That gets a gasp – but to cheer them up, I say that had I been speaking in Shakespeare’s time, two out of every three would be dead already.

To the students, their demise from cancer, heart disease or diabetes (all of which have an inherited component) seems immeasurably distant; and thanks to the latest research, it may be even further than they think. For the past century or so, life expectancy has been going up at the almost unimaginable rate of six hours a day, every day. Since I emerged into the world on the day of the Great Escape from Stalag Luft III (March 24, 1944) the average age at which a citizen can expect to survive for a further decade has risen by 10 years. In 1944 it was 70, but is now close to 80. These islands have almost 12,000 centenarians, four times more than in the 1960s. At the present rate, that will rise to 100,000 at the end of the century.

It is worth reminding ourselves, too, just how long-lived we already are in comparison with our fellow warm-blooded land animals. For them, each doubling of body weight leads to about a 16 per cent increase in length of life. We stand beyond that, for in spite of our modest size we live longer than any of them (elephants included).

Something is keeping us alive, and we do not know what it is. Now, a real Methuselah of the mammals is beginning to hint at what it takes to make a century. The African naked mole rat, whose name describes its charming appearance, has a pair of fearsome front teeth. It lives in burrows in which one aggressive female prevents all the others from mating and forces them to look after her own offspring. The animal is about the same size as a mouse, but it lives eight times as long, with plenty getting to 30 or so.

Once past our own teenage years, we age faster and faster. The average chance of death in a particular period doubles every eight years. The figures are more favourable in the prime of life and are at their best at the age of 10. If that schoolboy rate of mortality were to persist throughout life, most children born in 2000 would survive until the year 3300, which gives an uncomfortable insight into the power of bodily decay.

The mole rat does much better, for it stays young, healthy and fully fertile for almost all its days (which for an elderly animal is equivalent to an 80-year-old woman having the biological make-up of someone 50 years younger). And its longevity hints at some of the fundamental causes of ageing.

There are plenty of ideas around. One is that we poison ourselves with the by-products of our own metabolism; it has often been suggested that a restricted diet will help, or eating vitamins, fruit or vegetables, but the effects for people of normal weight are marginal at best.

Now, it seems that poisons from outside are more important: that fate depends not on how much you eat, but what it is. In the mole rat’s subterranean home, the only food and water comes from the roots and bulbs of plants growing above. Most plants are packed with all kinds of poisons – snowdrops, daffodils, and crocuses have bulbs that cause vomiting and worse, while garlic depends for its flavour on the same kind of stuff – and those in the African desert are even more noxious. So the mole rat has evolved defences that allow it to cope: its cells are so tough that they can deal with huge doses of lead, cadmium and other poisons and cope well with heat and starvation. Cells from other long-lived creatures (ourselves included) are also resistant to such stresses, hinting that an ability to deal with external challenges may be the source of longevity itself.

This year marks the 500th anniversary of the explorer Ponce de León’s search for the Fountain of Youth in Florida. A pill may soon emerge from the mole rat work to fulfil his dream. In the meantime, it seems the secret of long life is to have an embittered one, which should improve the prospects of today’s students as they cut down on beer to pay their tuition fees.

Please follow Science on Twitter and Facebook.

Join the conversation about this story »

Skywatchers all over the world jumped at the chance to view and photograph Friday's (Aug. 31) full moon, the last so-called "blue moon" until July 2015.

Friday's full moon was the second one to rise during the month of August, following the full moon of Aug. 1. This qualifies it as a blue moon, according to the popularly accepted (but incorrect) definition of the term.

"Blue moon" originally referred to the third full moon in a season that has four full moons instead of the usual three. But in 1946, a writer for "Sky and Telescope" magazine erroneously reported the second-full-moon-in-month meaning, and the definition stuck.

Friday's blue moon rose on the same day that late astronaut Neil Armstrong was memorialized in Cincinnati. Armstrong, the first person to walk on the moon, died Aug. 25 following complications from a recent heart surgery.

Several skywatchers thought of the famous moonwalker when they looked up last night. [Gallery: August 2012 Blue Moon]

"From Michigan, we are thinking of you, Neil," wrote Dennis Daniels, who photographed the full disk of the moon Friday night.

Blue moons aren't actually blue, unless clouds of smoke or volcanic ash in Earth's atmosphere lend them that particular hue. Rather, they usually look like any other full moon in the sky. [Photos: The Blue Moon and Full Moons of 2012]

However, some sky photographers, such as Johan Clausen of Denmark, used photographic effects to get pictures of blue-looking moons.

Another stunning photo of the blue moon was taken by photographer Ajay Talwar of "The World At Night," from India.

"Yesterday's blue moon was actually reddish when it rose over the Avenue Rajpath, New Delhi," Talwar wrote. "Actually it was lucky to have been visible at all during the Indian Monsoons."

Blue moons occur because lunar months and calendar months aren't perfectly synched up. It takes the moon 29.5 days to zip around our planet, during which time we see the satellite go through all of its phases. But Earth's months all have 30 or 31 days (except February), so once in a while two full moons get squeezed into a single month.

The moon looked markedly different from various locations around the world because of the different weather and atmospheric affects in each location.

An almost red moon was photographed over Evergreen Valley in Olympia, Wash., by Mary P. Bowman.

Before Friday night, the last blue moon occurred on Dec. 31, 2009. The next blue moon will come along on July 31, 2015.

The phrase "once in a blue moon" implies that the celestial phenomenon is incredibly rare, but it's really not. Blue moons occur on average once every 2.7 years, and sometimes much more frequently. In 1999, for example, two of them rose within three months. The next year that will see two blue moons is 2018.

If you snapped any good photos of Friday's full moon and would like them to be considered for a future story or gallery, please send them to SPACE.com assistant managing editor Clara Moskowitz at cmoskowitz@space.com.

Follow SPACE.com on Twitter @Spacedotcom. We're also on Facebook & Google+.

• The Blue Moon and Full Moon of 2012 (Photos)
• Will The Blue Moon Really Be Blue? | Video
• Once in a Blue Moon Event Is Not Really Blue (Infographic)

Please follow Science on Twitter and Facebook.

Join the conversation about this story »

A group of compounds used in a variety of products, including non-stick cookware, may influence a baby's growth in the womb and after birth, a new study suggests.

In the study, pregnant women who were exposed to high levels of polyfluoroalkyl compounds, or PFCs, had babies that were smaller at birth and larger at age 20 months compared with those born to women exposed to lower levels of the compounds.

The results held even after the researchers adjusted for factors that could influence the babies' weights, including the mother's smoking habits and weight before pregnancy.

The findings agree with previous studies on the effect of PFC exposure during in-utero development. A recent study in Denmark found that girls exposed to PFCs in the womb were more likely to be overweight at age 20, said study researcher Michele Marcus, a professor of epidemiology at Emory University's Rollins School of Public Health.

It's important to note the new study only found an association, and not a cause-effect link.

It's not clear how PFCs might influence growth rates, but it's possible they have an effect on fat metabolism, Marcus said.

Exposure in pregnancy

PFCs have thousands of uses in manufacturing, and most people have the compounds in their bodies. They are slow to break down, and persist for many years in the environment. They are commonly found in coatings of packaging products, as well as water-resistant clothing.

In the new study, Marcus and colleagues analyzed information from about 450 women living in England who were pregnant between 1991 and 1992, and gave birth to daughters.

Blood samples taken during pregnancy from the mothers were tested for the concentration of PFCs. Information about their children's weight and length were collected at birth, and again when they were 20 months old.

All of the mothers in the study had some PFCs in their blood. Girls born to mothers with the highest levels weighed about 5 ounces (140 grams) less on average at birth than girls born to mothers with the lowest levels.

By age 20 months, girls born to mothers with the highest blood levels of PCFs weighed 1.3 pounds (580 grams) more, on average, than girls born to mothers with the lowest levels.

The researchers were not able to examine the children's exposure to PFCs after birth, which may have affected the results, they said.

Because the women in the study had their blood collected about two decades ago, when PFC levels in the environment were higher, the findings do not tell us what the risks of exposure are to women who become pregnant now, said Dr. Magaly Diaz-Barbosa, medical director of neonatal services at Miami Children's Hospital, who was not involved in the study.

"While it would be reasonable for today's pregnant women to try to avoid exposure to these compounds, studies need to be conducted using more recent data before we can draw conclusions about the risks," Diaz-Barbosa said.

How to avoid PFCs

Pregnant women should avoid exposure to chemicals that could interfere with hormone signals, Marcus said.

To do this, Marcus recommended avoiding use of non-stick cookware (use iron or stainless steel instead), and not heating microwave food in its packaging.

"Cardboard food packaging is often coated with PFCs to prevent the food from sticking to the cardboard," Marcussaid.

Marcus also recommended not to heat food in plastic containers in the microwave.

The study was published online Aug. 30 in the journal Environmental Health Perspectives.

Pass it on: Exposure to PFCs in the womb may influence a baby's growth.

Follow Rachael Rettner on Twitter @RachaelRettner, orMyHealthNewsDaily @MyHealth_MHND. We're also on Facebook & Google+.

• 11 Big Fat Pregnancy Myths
• Top 5 Ways to Reduce Toxins in Homes
• Microwave Popcorn Bag Pollutants Make Vaccines Less Effective

Please follow Science on Twitter and Facebook.

Join the conversation about this story »

Guys' eyes are more sensitive to small details and moving objects, while women are more perceptive to color changes, according to a new vision study that suggests men and women actually do see things differently.

"As with other senses, such as hearing and the olfactory system, there are marked sex differences in vision between men and women," researcher Israel Abramov, of the City University of New York (CUNY), said in a statement. Research has shown women have more sensitive ears and sniffers than men.

"[A] recent, large review of the literature concluded that, in most cases females had better sensitivity, and discriminated and categorized odors better than males," Abramov and colleagues write Tuesday (Sept. 4) in the journal Biology of Sex Differences.

Abramov and his team from CUNY's Brooklyn and Hunter Colleges compared the vision of males and females over age 16 who had normal color vision and 20/20 sight — or at least 20/20 vision with glasses or contacts.

In one part of the study, the researchers asked the volunteers to describe different colors shown to them. They found that the guys required a slightly longer wavelength of a color to experience the same shade as women and the men were less able to tell the difference between hues. [Your Color Red Really Could Be My Blue]

The researchers also showed the participants images made up of light and dark bars that varied in width and alternated in color so that they appeared to flicker, a measure of participants' sensitivity to contrast. Compared with the women, the male volunteers were better able to identify the more rapidly changing images made up of thinner bars, the researchers said.

Abramov explained in a statement these elements of vision are linked to specific sets of thalamic neurons in the brain's primary visual cortex. The development of these neurons is controlled by male sex hormones called androgens when the embryo is developing into a fetus.

"We suggest that, since these neurons are guided by the cortex during embryogenesis, that testosterone plays a major role, somehow leading to different connectivity between males and females," Abramov said. "The evolutionary driving force between these differences is less clear."

Previous research found that men and women also focus differently. In experiments at the University of Southern California, researchers found that men are likely to fixate on the mouth of a person in conversation and also are more likely to be distracted by movement behind that person. Meanwhile, women tend to shift their gaze between a speaker's eyes and body, and they are more likely to be distracted by other people, the researchers found.

Follow LiveScience on Twitter @livescience. We're also on Facebook & Google+.

• 5 Myths About Women's Bodies
• Busted! 6 Gender Myths in the Bedroom & Beyond
• 10 Things Every Woman Should Know About a Man's Brain

Please follow Science on Twitter and Facebook.

Join the conversation about this story »

The aftermath of Hurricane Isaac has washed ashore tens of thousands of dead "swamp rats," invasive species whose rotting corpses are now presenting a health hazard in Mississippi.

The drowned rodents, known as nutria, are a stark reminder of the effects of hurricanes on wildlife, which can range from mass death to — surprisingly enough — dolphin baby booms. In the case of the nutria, the drownings may be a blessing for the Gulf Coast, where the beaver-like creatures wreck havoc on native marsh vegetation.

The clean-up, though, is proving unpleasant.

"They're actually starting to swell up and bust," Hancock County Supervisor David Yarborough told local news station WLOX. "It smells really bad." [See Photos of the Nutria Washed Ashore]

Animals and hurricanes

Nutria aren't the only animals to suffer after hurricanes. A study of alligators in southwest Louisiana after Hurricane Rita hit in 2005 found that the reptiles were physically stressed a month after the initial storm surge inundated their marshy habitat. Blood tests on the gators showed elevated stress hormones as well as other signs of ill health, the researchers reported in February 2010 in the Journal of Experimental Zoology Part A: Ecological Genetics and Physiology.

Research on Florida manatees has suggested that docile "sea cows" die more frequently during years with extreme storms, perhaps due to immediate causes like getting swept out to sea, or perhaps due to post-hurricane environmental changes such as cooling in coastal waters, according to a 2006 paper published in the journal Estuaries and Coasts. That study tracked a handful of manatees through the 2004 and 2005 hurricane seasons and found that the animals tended to "ride out" the storms in place rather than attempt to avoid them. 

Other studies have found changes in fish populations right after hurricanes, as well as changes in phytoplankton, the algal basis of the ocean food chain, though these changes are short-lived. Sometimes, though, hurricane effects echo over long time periods. A 2010 study on bottlenose dolphins found that two years after Hurricane Katrina, the number of baby dolphins in the Gulf of Mexico suddenly skyrocketed. [Photos: World's Cutest Baby Animals]

Some of the jump could be explained by dolphin mamas getting pregnant sooner than usual after losing their previous calves in the storm, the researchers reported in the journal Marine Mammal Science. But the storm had another effect: It destroyed a significant chunk of the Gulf of Mexico fishing fleet. Fewer fishermen meant more food for dolphins and their young, the researchers concluded.

Nutria death zone

Mississippi's nutria population took a hit from Isaac. Sanitation workers have been cleaning up the carcasses with pitchforks and front-end loaders.

"Estimates are there will be over 20,000 carcasses, but that is unclear now," Robbie Wilbur, a spokesman for the Mississippi Department of Environmental Quality, told LiveScience. "Eventually, the totals will be numerated in tons when they're all disposed."

The carcasses are being sent to the Pecan Grove landfill in Harrison County, Miss., Wilbur added.

"It's starting to get bad," said Mark Williams of the Department of Environmental Quality's Solid Waste Management branch. "It's heated up over the last two or three days, and of course that really expedites the degradation process."

Nutria are native to South America, but the rodents were brought to North America in the late 1800s and farmed for their fur. Escaped and released nutria established themselves in the marshes of the Gulf Coast, where they gnaw the roots of marsh plants, destroying the vegetal web that keeps the marshes from washing away.

Hurricane Isaac likely won't set Mississippi's nutria population back for long. Nutria can produce litters with as many as 13 babies, and they're capable of reproducing twice a year starting at as early as four months of age. Baby nutria begin supplementing their mother's milk with marsh vegetation within hours of birth.

Follow Stephanie Pappas on Twitter @sipappas or LiveScience @livescience. We're also on Facebook & Google+. 

• In Images: Hurricane Isaac
• Image Gallery: Invasive Species
• The 10 Weirdest Animal Discoveries

Please follow Science on Twitter and Facebook.

Join the conversation about this story »

New hope was raised yesterday for people left paralyzed by injury, after doctors said they had succeeded in using stem cells to restore feeling in two patients.

In a world first, doctors at Zurich University said two out of three men who had agreed to take part in an early trial, had regained some sensation below the level of their injuries.

It is the first time anyone has reported a positive outcome from stem cell therapy for severe spinal cord injury - and holds out the possibility of greater things in years to come.

The ultimate aim is to help those paralysed by injury to walk again.

Stem cells are special cells that can turn themselves into almost any kind of cell in the body. Those from human embryos have that absolute ability, while 'adult' stem cells have already specialized to a degree. For instance, neural stem cells can special ise into different type of nerve cells, but not something else like muscle or blood cells.

The trial worked on the theory that injected adult stem cells would transform themselves into spinal cord nerves, reconnecting brain and lower body.

Professor Armin Curt, leading the study, described the result as “fundamental”.

He said: “To find something that can repair the spinal cord is a huge breakthrough. If we can show that something has changed for the better [as a result of stem cell therapy] that’s fundamental.”

He presented the findings at the annual conference of the International Spinal Cord Society in London on Monday.

Prof Curt was working in partnership with StemCells Inc., a Californian company which also has a base in Cambridge.

Dr Stephen Huhn, from the firm, said: “We think these stem cells are one of the first tools we have for actually repairing the central nervous system.

"To see this kind of change in patients who truly have the worst-of-the-worst type of injury to the spinal cord is very exciting."

The three patients, who all had complete spinal injury where they could feel nothing below the break, were each given a dose of 20 million ‘adult’ neural stem cells about six months ago.

This was primarily a safety trial, and Prof Curt said monitoring had shown “a very good safety profile”.

But detailed questioning and objective tests also showed signals were passing up the injured spine to the brain, when they had not before.

One of the patients, Knut Ølstad, a 46-year-old Norwegian financial consultant, said: “I’ve noticed changes. When somebody touches my stomach, I can feel something. I can’t be specific, but I can sense it.”

Mr Ølstad was paralysed from the mid-chest down last summer during a cycling holiday in the Alps.

On his last descent, having cycled over 500 miles and climbed the equivalent of two Everests, he was flipped over the handlebars after braking to avoid a car.

The recent improvement was modest, but he said: “It provides me with hope for the future.”

He believed stem cells could one day help him and others like him walk again.

Prof Curt was cautious about that possibility, but Dr Huhn said: “I think it’s in the realm of possibility.”

Stem cell research for spinal injury “requires an incremental approach where we build the therapy one brick at a time”, he added.

Walking was not the only aim: people paralysed through injury also wanted to regain sensation, bowel and sexual function, he said.

The results come almost a year after another US firm, Geron, pulled out of a similar trial using embryonic stem cells, citing cost concerns.

Please follow Science on Twitter and Facebook.

Join the conversation about this story »

Exploding stars carve out gas cavities called superbubbles in a nearby dwarf galaxy, as shown in a new photo from the Chandra space telescope.

This photo reveals a superbubble in the Large Magellanic Cloud, a small satellite galaxy of our own Milky Way, that lies roughly 160,000 light-years away from Earth.

Chandra's X-ray observations are shown here in blue light, which represents hot regions. The red light in the photo is from NASA's Spitzer Space Telescope, which sees infrared light from areas containing dust and cooler gas. Meanwhile, optical light is shown here in yellow in observations from the 2.2-meter Max-Planck-ESO telescope in Chile, which sees ultraviolet radiation from hot, young stars.

Combining all these wavelengths, this composite picture helps give astronomers a fuller understanding of this dynamic region. Many of the bright stars belong to the star cluster NGC 1929, which is embedded in the nebula N44, inside the Large Magellanic Cloud.

Superbubbles are formed when massive stars reach the ends of their lives, exploding in powerful bursts called supernovas that send out shockwaves through space. These shockwaves and winds push gas outward to carve out huge cavities in space.

However, many of the details of how this works remain a mystery. Some superbubbles, including the one in N44, release more X-ray light than current theories suggest they should. This new photo helps astronomers distinguish between the different sources of X-ray emission in this region to try to account for the light they observe.

Follow SPACE.com on Twitter @Spacedotcom. We're also on Facebook & Google+. 

• Spectacular Photos of Nebulas in Deep Space
• Supernovas Blow Superbubble In Nearby Star Cluster | Video
• Supernova Photos: Great Images of Star Explosions

Please follow Science on Twitter and Facebook.

Join the conversation about this story »

He has shot a grey whale with a sample-collecting dart in the Pacific, released leopards in the Caucasus and "saved journalists from wild tigers", now Vladimir Putin's latest episode of animal antics takes him into the Siberian skies as a surrogate parent leading a flock of endangered cranes.

The stunt-prone Russian president will personally pilot a motorised hang-glider during a stopover in the far north of the country this week on his way to the Asia-Pacific Economic Co-operation Forum in Vladivostok.

There are only 20 Siberian white cranes left in the world. Putin will lead a group of the birds on the first leg of their 5,000km migration and, if all goes to plan, they will spend the winter in central Asia.

Six months into his third presidential term and a month from his 60th birthday, Putin will have to don white overalls and a special beak to be recognised by the cranes, Yuri Markin, an ornithologist and director of the Oksk Nature Reserve, where the young birds were raised, told the RBC news website.

Putin has cultivated an image as an animal lover during his time at the top of Russian politics and has even been given a tiger cub as a birthday present.

During a televised phone-in session last year, when he was prime minister, a viewer asked why Putin looked more comfortable with tigers and leopards than his own ministers. "The more I know people, the more I like dogs," Putin replied, paraphrasing the greek philosopher Diogenes. "I simply like animals."

But observers will be watching the latest stunt carefully for any signs of a set up. There was widespread disbelief in 2008 when Putin appeared to save a television crew from a rare Amur tiger in Russia's far east by shooting it with a tranquiliser  gun.

And even the Kremlin's press service was forced to admit last year that footage and photographs of Putin striding away from a dive in the Black Sea having recovered Greek amphorae was planned in advance, with the jars having been planted on the sea floor.

Putin has been undergoing special training to be able to fly the motorised hang-glider and will take part in the "Flight of Hope" that begins in the Yamal district of northern Russia as long as the weather is favourable, his press secretary, Dmitry Peskov, told Russia's Vedomosti newspaper on Wednesday.

After helping the birds on their way, Putin will take a more conventional plane on Friday to Vladivostok, where he will greet heads of state from around Asia and the Pacific at the annual Apec summit, which Russia is hosting.

A row about Putin's date with the endangered cranes was already under way in Moscow before official confirmation of the stunt.

Russia's oldest scientific magazine, Vokrug Sveta, lost its chief editor, Masha Gessen, on Monday after she resisted pressure to send a reporter to cover the event. "I'm leaving Vokrug Sveta #thankstoPutinforthat", Gessen tweeted later that day.

She said that she considered the request to publish material about Putin's involvement with the Siberian white cranes to have been "editorial interference".

The outspoken journalist is also the author of a critical biography about Putin that was released last year with the title The Man Without A Face: The Unlikely Rise of Vladimir Putin.

Guided migrations for young birds that would otherwise not know where to go were made famous by the 1996 Hollywood film Fly Away Home, in which a girl befriends a group of geese, overcomes crashes and the loss of her mother to fly a microlight to take them to their wintering grounds.

This article originally appeared on guardian.co.uk

Please follow Science on Twitter and Facebook.

Join the conversation about this story »

"Men think about sex every seven seconds"

Nope. More like an average of every 158 seconds.

"Nice guys finish last"

It depends. Over the long run, being a nice guy can lead to happiness, success and good relationships. On the other hand, they aren't as likely to end up in prestigious positions or to be chosen as leaders when times are tough. Rude people have higher credit scores and jerks make more money. And it can be hell on your love life: young women and women who most enjoy sex prefer bad boys.

Read The Rest At Barking Up The Wrong Tree >

Please follow Science on Twitter and Facebook.

Join the conversation about this story »