No more pause: Warming will be non-stop from now on

Enjoy the pause in global warming while it lasts, because it's probably the last one we will get this century. Once temperatures start rising again, it looks like they will keep going up without a break for the rest of the century, unless we cut our greenhouse gas emissions.

The slowdown in global warming since 1997 seems to be driven by unusually powerful winds over the Pacific Ocean, which are burying heat in the water. But even if that happens again, or a volcanic eruption spews cooling particles into the air, we are unlikely to see a similar hiatus, according to two independent studies.

Masahiro Watanabe of the University of Tokyo in Japan and his colleagues have found that, over the past three decades, the natural ups and downs in temperature have had less influence on the planet's overall warmth. In the 1980s, natural variability accounted for almost half of the temperature changes seen. That fell to 38 per cent in the 1990s and just 27 per cent in the 2000s.

Instead, human-induced warming is accounting for more and more of the changes from year to year, says Watanabe. With ever-faster warming, small natural variations have less impact and are unlikely to override the human-induced warming.

"The implication is that we will get fewer hiatus periods, or hiatus periods that last for a shorter period," says Wenju Cai at the CSIRO in Melbourne, Australia, who wasn't involved in the work.

Stop it

According to another recent study, the current hiatus may be our last for a while. Matthew England and his colleagues at the University of New South Wales in Sydney, Australia, tried to quantify the chance of another pause. "It's looking to us that it's probably going to be the last one that we'll see in the foreseeable future," says England.

Using 31 climate models, they showed that if emissions keep rising, the chance of a hiatus – a 10-year period with no significant warming – drops to virtually zero after 2030. The current hiatus will probably be followed by rapid warming as the heat trapped in the ocean escapes back into the atmosphere, so we are unlikely to get another decade of no warming before 2030. England believes it could be another century or more before the next hiatus.

But that could change if we slow greenhouse gas emissions now. If we can reach peak global emissions by 2040, the temperature rise will slow by the end of the century, and hiatus periods will become more likely.

Hiatuses can also be triggered by volcanic eruptions that spew particles into the air, reflecting sunlight away from Earth, as happened after the 1991 Mount Pinatubo eruption. But even if a volcano erupts it will make little difference. "After 2030, the rate of global warming is likely to be so fast that even large volcanic eruptions on the scale of Krakatoa are unlikely to drive a hiatus decade," says team member Nicola Maher.

Journal references: Watanabe: Nature Climate Change, DOI: 10.1038/nclimate2355; Maher: Geophysical Research Letters, DOI: 10.1002/2014GL060527

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New push for better handling of football head injuries

Seeing stars? It may be from one header too many. Following a class-action lawsuit filed in California on Wednesday, there is growing pressure for FIFA – soccer's international governing body – to limit the potential for brain damage from the beautiful game.

The lawsuit has been brought by a group of players and parents in the US. It claims that FIFA, alongside a number of US soccer organisations, have been negligent in their handling of head injuries.

Rather than seeking financial compensation, the plaintiffs are asking for the rules of football to be changed to better prevent and manage concussion in the sport. One proposal is to allow a temporary substitution of an injured player so that they can be properly examined.

Clash of heads

The lawsuit comes after some players at this year's FIFA World Cup in Brazil received little immediate medical treatment following nasty head clashes. For instance, Uruguay's Álvaro Pereira was left unconscious after his head came into contact with the knee of England's Raheem Sterling during one fixture – but he continued to play once he had come round. In the semi-finals, the Netherlands' Georginio Wijnaldum clashed heads with Argentina's Javier Mascherano, and in the final Germany's Cristoph Kramer played on for half an hour after suffering a blow to the head.

If our handling of such injuries could be improved, so too could our understanding of the risks and long-term effects of head contact in football. "What exactly happens to sportsmen in these games? We don't actually know," says John Hardy, a neuroscientist at University College London. "We don't know in a quantitative way what happens and what the effects are." Hardy says careful analysis of players and the game is needed.

Antonio Belli, a neurosurgeon at the University of Birmingham, UK, says that perhaps three bouts of concussion could be enough to cause permanent brain damage. Some studies suggest that even repeated head-to-ball contact, a normal part of the game, might lead to reduced cognitive function, possibly caused by damage to the brain's frontal lobes.

New impetus

This month, both FIFA and the English Football Association (FA) released statements outlining plans for research into footballing head injuries. "The World Cup this year probably did the world of concussion in sport a favour, because it's provided a huge impetus for having rules and regulations in place to more robustly manage it," says Craig Ranson, a sports physiotherapist at Cardiff Metropolitan University in the UK.

FIFA's ongoing research efforts include a study of Swiss football players throughout the 2014-15 season. Both male and female players received a neurological assessment before the season began, and will undergo follow-up examinations should they experience a head injury. The study could help reveal how lasting concussion is, and when it is safe for an injured player to return to the game. "The thing to try and work out is if there is any physical problem with the brain after concussion," says Ranson.

The FA is taking a longer view. It has announced plans to research head injuries following a meeting with the family of former player Jeff Astle, who died aged 59 in 2002 from chronic traumatic encephalopathy – a condition more often seen in boxers.

Willie Stewart, a neuropathologist at the Southern General Hospital in Glasgow, UK, diagnosed Astle's condition, and has been in discussions with the FA. "I'm hoping to work with them to look at the incidence of dementia and neurological illness in retired footballers," says Stewart. He says the work can be done relatively quickly and will give an insight into whether this is a big problem. "Anecdotally, the answer would seem to be yes," Stewart says.

Limits on heading

Should research show that the sport significantly contributes to neurological conditions, Stewart says preventive measures will be the best way forward. "That may mean modifications of the way the game is played, [such as] modifying the age that kids start to head footballs, or limiting heading practice."

Compared to other sports, head clashes are rare in football, says Ranson. "But when they do occur, can they be managed better so that the player' is not at risk?" In rugby, players must leave the pitch if they sustain a head injury, and it is the team doctor that decides whether the player can return. A similar approach is being tried in the English Premier League for the first time this season.

But sports psychology will play an important role too, as pumped-up professional players are unlikely to want to be sent back to the bench following a potential head injury. "There's very good evidence that players will do their best to hide symptoms because they don't want to lose playing time," says Belli. He says better education about the signs and risks of concussion are needed. "We need a better objective test of concussion, and that's something the world of sport is desperately trying to come up with," says Stewart.

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Today on New Scientist

Soviet dog spacesuit for pooches with the right stuff

Your canine companion can strut its stuff in this authentic Soviet spacesuit, worn by genuine doggy heroes of the space race Belka and Strelka

Painful memories eased by inhaling xenon gas

The odourless, colourless and mostly inert gas xenon has been used to ease painful memories in mice. It could help us to forget our own past traumas

Earth's tectonic plates have doubled their speed

The latest study suggests Earth's plates today move twice as fast as they did 2 billion years ago – maybe because the mantle has got more runny

Voyager 2's view of solar system's edge will be unique

There's reason to think Voyager 2's sensors will pick up changes that contrast with what Voyager 1 saw en route to the edge of interstellar space

Emailing angry? Your keyboard feels your pain

By measuring the way you are typing, a computer program can detect how you are feeling with 80 per cent accuracy

Beautiful spiral cracks could be a feature, not a flaw

Unusually uniform, watercolour-like fractures that form in high-tech materials could be used to manufacture micro-patterned surfaces

Feedback: Tipping the quantum scales

The appliance of science, fake delusions equal profit, sinister buttocks in essays and more

Let's talk about the weather to revive climate debate

Explaining how climate change is affecting today's weather will be tricky, but it might bring home to the public the everyday reality of global warming

3D-printed books make pictures real for blind children

Children's classics like The Very Hungry Caterpillar have come to life for visually impaired children thanks to 3D-printed Braille text and tactile pictures

A to zinc: What supplements are worth taking?

Vitamins, minerals, fish oils… the list of nutritional supplements you can buy keeps growing. Some are worth it, some aren't. We sift the evidence for you

Ferguson protests spark calls for cops to wear cameras

On-body cameras mean police use less force, and a range of new apps are giving citizens new ways to hold errant police officers to account

Moving home? Your microbes will make the trip too

Families have identifiable collections of microbes that travel with them. It can take just 24 hours for the microbes to take over a new house

Taming of the bunny rewrote rabbit genome

When rabbits were domesticated, around 100 regions of their genome changed to make them less fearful, but the variations are not fixed

Mapping the web of disease in Nairobi's invisible city

Peter Guest discovers how studying the way diseases jump from animals to humans sometimes means wrestling pigs in a slum that doesn't officially exist

Fossil dinosaur nursery includes babysitter's bones

A crèche of 30 dinosaur infants looked over by an older animal shows that even terrible lizards needed a night away from the kids

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Soviet dog spacesuit for pooches with the right stuff

(Image: Auctionata)

Tempted to dress up your dog as a Soviet space pioneer? Keep it real by investing in this genuine 1950s doggy spacesuit, used to test the effects of low gravity and high-speed launches. Although, judging by this model dog's expression, your dogmonaut may not enjoy the experience as much as you do.

The lace-up, full-body suit comes complete with an oxygen supply tube, and will be going on the auction block on 13 September with an estimate of €8000. Made out of cotton, nylon, rubber and aluminium, the suit is believed to have been used during the training of the dogs Belka and Strelka for the USSR's Korabl-Sputnik 2 mission.

While the US used chimpanzees in their space race tests, Russian scientists chose dogs, because of their willingness to sit still for long periods. Some of the tests involved strapping dogs into capsules and launching them to a height of 80 kilometres. The capsules then returned to Earth by parachute.

The dog Laika became the first animal to orbit the Earth in 1957, dying from stress and overheating around 6 hours into the flight. Belka and Strelka were luckier: in 1960, they became the first dogs to return to Earth safely, having spent a day in space.

Strelka subsequently gave birth to six puppies, one of which was presented as a gift to John F. Kennedy's family.

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Painful memories eased by inhaling xenon gas

It's odourless, colourless, tasteless and mostly non-reactive – but it may help you forget. Xenon gas has been shown to erase fearful memories in mice, raising the possibility that it could be used to treat post-traumatic stress disorder (PTSD) if the results are replicated in a human trial next year.

The method exploits a neurological process known as "reconsolidation". When memories are recalled, they seem to get re-encoded, almost like a new memory. When this process is taking place, the memories become malleable and can be subtly altered.

This new research suggests that at least in mice, the reconsolidation process might be partially blocked by xenon, essentially erasing fearful memories. Among other things, xenon is used as an anaesthetic.

Frozen in fear

Edward Meloni and his colleagues at Harvard Medical School in Boston trained mice to be afraid of a sound by placing them in a cage and giving them an electric shock after the sound was played. Thereafter, if the mice heard the noise, they would become frightened and freeze.

Later, the team played the sound and then gave the mice either a low dose of xenon gas for an hour or just exposed them to normal air. Mice that were exposed to xenon froze for less time in response to the sound than the other mice.

When mice that weren't exposed to xenon were later placed in the cage where the sound and shocks were produced, they spent 70 per cent of the first two minutes frozen. But mice that had been given xenon treatment spent less than 30 per cent of the time frozen. Playing the sound cue induced more fear in the xenon-exposed mice, but they still only spent about 40 per cent of the two minutes following the sound frozen. "It was as though the animals no longer remembered to be afraid of those cues," says Meloni.

Xenon does several things in the brain, so pinning down exactly how it works could be difficult. But Meloni's team tried the gas because it blocks NMDA receptors, which are involved in memory formation and reconsolidation.

Forget and fear not

"Unlike other drugs or medications that may also block NMDA receptors involved in memory, xenon gets in and out of the brain very quickly," says Meloni. "This suggests that xenon could be given at the exact time the memory is reactivated, and for a limited amount of time, which may be key features for any potential therapy used in humans."

"This is an interesting study, which opens lots of questions for future research," says Elizabeth Phelps of New York University, who studies the interplay between memory and fear. But she warns that such work has limitations. "These are simple associative threat memories. Many people use these paradigms to study aversive memory representations that are relevant to understanding PTSD, but the evidence that this simple learning model is a sufficient model for the extensive pathology that encompasses PTSD is not great."

Nevertheless, Meloni says it's a useful guide, and helps us to understand the dysfunctional learning and memory process involved in maintaining some aspects of PTSD. He hopes to start trials on healthy humans within a year, and if that works, move on to patients who have been diagnosed with PTSD.

Journal reference: PLoS One, DOI: 10.1371/journal.pone.0106189

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Earth's tectonic plates have doubled their speed

SO MUCH for slowing down as you age. Earth's tectonic plates are moving faster now than at any point in the last 2 billion years, according to the latest study of plate movements. But the result is controversial, since previous work seemed to show the opposite.

If true, the result could be explained by another surprising recent discovery: the presence of more water within Earth's mantle than in all of the oceans combined.

Plate tectonics is driven by the formation and destruction of oceanic crust. This crust forms where plates move apart, allowing hot, light magma to rise from the mantle below and solidify. Where plates are being pushed together, the crust can either rise up to form mountains or one plate is shoved under the other and is sucked back into the mantle.

The planet's inner heat powers plate tectonics. That heat is ebbing away as Earth ages, and this was expected to slow plate motion. A study last year by Martin Van Kranendonk at the University of New South Wales in Sydney, Australia, and colleagues measured elements concentrated by tectonic action in 3200 rocks from around the world, and concluded that plate motion has been slowing for 1.2 billion years.

Now Kent Condie, a geochemist at the New Mexico Institute of Mining and Technology in Socorro and his colleagues have used a different approach and concluded that tectonic activity is increasing. They looked at how often new mountain belts form when tectonic plates collide with one another. They then combined these measurements with magnetic data from volcanic rocks to work out at which latitude the rocks formed and how quickly the continents had moved.

Both techniques showed plate motion has accelerated. The average rate of continental collisions, and the average speed with which the continents change latitude, has doubled over the last 2 billion years (Precambrian Research, doi.org/vbv).

"We expected to find that the average speed would be slowing down with time, but we didn't get that. Both speeds were going up," says Condie. "It was a surprise."

Condie thinks the mantle's huge store of water could explain the finding. When crust sinks back into the mantle, oceanic water gets sucked down too, and although most comes back to the surface in volcanic emissions, over the aeons the store of water in the mantle has grown vast.

Some of this water forms hydrous minerals that essentially make the mantle more runny, says Condie, speeding up the flow of rock. The effect is strong enough to overcome the stiffening of the mantle caused by the gradual cooling inside Earth, he says.

Peter Cawood at the University of St Andrews in the UK thinks the work is interesting and provocative. "The overall increase in the rate of plate motion with time seems real and believable," he says, and could well be linked to changes in the mantle's water content – although convincing sceptics that plates move faster now will be difficult without more data, he adds.

Van Kranendonk is not ready to change his mind. "Our paper documents a reduction in the rate and volume of crustal recycling for 1.2 billion years, supporting the idea that plate tectonics actually has been slowing down since that time," he says.

This article appeared in print under the headline "Earth's tectonic plates in high-speed controversy"

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Voyager 2's view of solar system's edge will be unique

Earth's second emissary to interstellar space, Voyager 2, is phoning home with new views of the solar system's ragged edge. But what it sees could be very different to what its predecessor glimpsed, revealing new details of the sun's immediate neighbourhood.

Voyager 2 has reached the heliosheath, the beginning of the end of the solar system. If the experience of its twin, Voyager 1, is anything to go by, Voyager 2 is about two-thirds of the way to the heliopause – the outer edge of the sun's influence, also considered to be where interstellar space begins. Voyager 1 crossed this boundary two years ago this week, according to NASA and most Voyager scientists. Not everyone agrees, though, because readings sent back by Voyager 1 left a little room for doubt.

One clue that Voyager 1 had passed the heliopause was that its instruments measured a slowing, sparser solar wind. That's not happening yet for Voyager 2, says Rob Decker at Johns Hopkins University in Maryland.

Windsock-shaped sphere

That could be because the sun's sphere of influence isn't a sphere. Solar radiation blows a bubble of charged particles about 15 billion kilometres in radius, but the sun's motion through the galaxy gives that bubble a windsock shape, with a rounded part in the direction of travel and a tail trailing behind. Voyager 1 is moving in the same direction as the sun, but Voyager 2 – 3 billion kilometres behind – is headed more sideways and down.

In addition to the sun's motion, particles and plasma from interstellar space might be deforming the bubble, Decker says. As a result, it could take longer for Voyager 2 to reach interstellar space – or it could happen sooner, notes Ed Stone, chief Voyager scientist at NASA. Voyager 2 crossed the termination shock, another physical boundary signifying the heliosheath, about 1.5 billion kilometres before anyone expected, he says, so it's hard to make firm predictions about what it will do in the future.

When Voyager 2 does cross the heliopause, its exit will be definitive, Decker and Stone say. Voyager 1's plasma sensor broke down sometime in the 1980s, but the younger probe's still works. The sensor will detect the change between the sun's sphere of influence, which is warm and less dense, to the interstellar medium, which is cold and denser by a factor of 40. That means Voyager 2's observations will be much clearer.

"We're very fortunate to have a second spacecraft," Stone says.

Journal reference: The Astrophysical Journal, DOI: 10.1088/0004-637X/792/2/126

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Emailing angry? Your keyboard feels your pain

FACEBOOK, email, texting, instant messaging – more of our life than ever is lived through our keyboards. Communicating emotion through type can be hard, though.

That could be about to change. By measuring the way someone is typing – the speed, rhythm and how often they use backspace – and then combining that information with an emotional analysis of the typed text, a computer program has been able to predict how they are feeling with 80 per cent accuracy.

Nazmul Haque Nahin and colleagues at the Islamic University of Technology in Bangladesh asked volunteers to type phrases presented to them on a screen, including passages from Alice's Adventures in Wonderland. First they built a model by measuring and recording information on how people type while also asking them how they were feeling – joyful, guilty, disgusted or tired, for example. When the volunteers were asked to carry out the task a second time, the software used this model to predict how a person was feeling as they were typing.

Tested on different emotions, the program successfully detected joy 87 per cent of the time, while anger was identified 81 per cent of the time (Behaviour and Information Technology, doi.org/vbt).

This isn't the first attempt to measure emotions through a keyboard. A team led by Clayton Epp at the University of Saskatchewan in Canada found that anger and excitement were the easiest emotions to detect, because they were only expressed for short periods of time.

"The objective is a good one," says Joshua Feast, CEO of Cogito, a firm that provides behaviour and voice analytics. "These types of tools can provide automated feedback to individuals to increase self-awareness."

Although monitoring typing comes with overtones of surveillance, Feast says there are lots of useful applications, such as alerting people when they are typing an email while angry.

Epp foresees an "emotional instant messaging client": an app that works like a more sophisticated form of emoticon. Subtle cues would alert the recipient to the emotional message's tone, allowing people to communicate more naturally.

This article appeared in print under the headline "Emailing angry? Your keyboard feels your pain"

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Beautiful spiral cracks could be a feature, not a flaw

UNUSUALLY beautiful and uniform cracks that form in high-tech materials could be used to manufacture micro-patterned surfaces.

Joël Marthelot of ESPCI ParisTech in France and his colleagues noticed the cracks when studying thin films of silicate materials, which are used as a coating inside lasers.

If the coating doesn't quite stick to the surface below, cracks can form that spiral around a central point or that etch out regular rows of crescents. Optical effects caused by the film lifting from the surface produce watercolour-like hues.

Other researchers had seen these cracks in similar materials, but no one had studied how they formed. Investigating further, Marthelot and his colleagues realised that a combination of elastic energy within the film and the process of peeling away from the underlying surface makes an initial crack replicate itself an interval that depends on the thickness of the film (Physical Review Letters, doi.org/vb5).

These regular patterns could be useful in processes such as creating microscopic channels for transporting liquids. "Usually fracture is seen as failure and something you have to avoid," says Marthelot, who is now at the Massachusetts Institute of Technology. "We can think about using such cracks as tools to make patterns at small scales."

"It's a nice piece of work, the pictures are beautiful," says Nicolas Vandenberghe of Aix-Marseille University in France. "Maybe cracks will become a useful process to manufacture or design specific things."

This article appeared in print under the headline "Spiral cracks are a feature, not a flaw"

Correction, 28 August 2014: When this article was first published, the affiliation for Joël Marthelot was incorrect.

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Feedback: Tipping the quantum scales

Feedback is our weekly column of bizarre stories, implausible advertising claims, confusing instructions and more

INSPIRED by reports of experiments that show ever-bigger objects demonstrating quantum properties, Andrew Scott would like to propose some further research. The largest object that Feedback is aware of having gone through two points "at once" is a "buckyball", the near-spherical carbon-based molecule that is just visible under a microscope (8 May 2010, p 37).

Andrew is "wondering what would happen if we tried to narrow down the size range for quantum effects", working down from larger objects. He suggests that "we could begin by letting cats wander through two cat flaps towards a wall smeared with catmint and record the points they touch first". Funding, anyone?

"There is a fault with departure screens," read a display at Dewsbury station: "please disregard the information shown." So they were working?

FURTHER, reports of experiments ...

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Let's talk about the weather to revive climate debate

Explaining how climate change is affecting today's weather will be tricky, but it might bring home to the public the everyday reality of global warming

LULL in the conversation? You can safely bring up the weather – no matter who you're chatting with, no matter where in the world you are. Unless you're talking to a climate scientist, that is.

Unlike the rest of humanity, climate researchers have long avoided discussing what's going on outside the window – be it a heatwave or cold snap, drought or deluge. Their studies have revealed that the weather will change dramatically over the long term, but they shy away from what it's doing right now.

That's changing. Thanks to advances in climate modelling, researchers can now assess how much more or less likely climate change has made individual extreme weather events. With enough computing power, this could even become part of your daily weather report (see "And now the weather, featuring climate change blame").

Those driving this effort hope that discussing climate change in the context of today's weather, rather than last year's, will help make it more tangible to a largely confused or indifferent public. Will it? You could argue that when describing a system as complex, variable and chaotic as Earth's climate, it's a good strategy to avoid sweating the small stuff and focus on the big picture: the ample evidence that pumping greenhouse gases into the atmosphere is causing the planet to warm, in turn causing the climate to change – with profound consequences (New Scientist, 7 December 2013, page 34).

The problem, of course, is that this picture has failed to stir much of the public to action: "global warming" still appears far down the list of US voters' priorities, for example. Climate change, as it is usually presented, falls squarely into the category of problems we find it hard to engage with – a seemingly remote threat calling for immediate sacrifices (16 August 2014, page 24).

The effects of the weather, on the other hand, are far more visceral: we don't need much persuasion to take an umbrella out when clouds loom. In fact, in recent years public opinion has been quick to attribute freak weather events to climate change. This may or may not have been warranted, but it does suggest that many people would be receptive to meteorologists revealing human fingerprints on the weather.

How much of this laypeople will really understand is a different question. Talk of climate change "increasing the likelihood" of a weather event, rather than simply "causing" it, is potentially confusing, but blurring the distinction would be disingenuous at best and dishonest at worst.

It will provide fodder for scepticism, too, of both the naive and calculated varieties. The unfair but enduring dictum that the weather forecast always gets it wrong is likely to be aired frequently, while those motivated to deny climate change will seek to highlight "anomalies" in the hopes of muddying the water, just as they gloat meaninglessly over every cold snap now. Lawyers, politicians and businesses will weigh in as and when it suits them.

All this potential for sound and fury should not obscure the value of talking about climate change in everyday contexts. In fact, the potential to reinvigorate the conversation is its value. Empty "debate" over the actuality of climate change has nothing to offer, so it's time to find a fresh topic. How's the weather where you are?

This article appeared in print under the headline "Stormy weather ahead"

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3D-printed books make pictures real for blind children

TIME to get hands-on. A new project is printing Braille picture books for visually impaired children. Each page turns the pictures from the original book into raised 3D shapes alongside traditional Braille text.

"The advantage of 3D-printing is really about making one-of-a-kind objects," says Tom Yeh, who heads up the Tactile Picture Books Project at the University of Colorado at Boulder. Later this year, Yeh's group will work with the National Braille Press in Boston to offer children a copy of Dragons Love Tacos by Adam Rubin that has a page customised with the child's name in Braille.

Over the past few months, the team has used this method to print children's classics like Goodnight Moon and The Very Hungry Caterpillar. Copies were given to children at the Anchor Center for Blind Children in Denver. In the future they hope people can print their own Braille stories on demand.

The 3D-printed books can be rather fragile, says Alice Applebaum, the centre's executive director. But she is excited about the possibility of using Yeh's books to help students learn to read. "Since our children have limited or no vision, having a book that they can feel gives them a sense of what the world looks like," Applebaum says.

This article appeared in print under the headline "3D printed books get personal for blind children"

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A to zinc: What supplements are worth taking?

(Image: Angus Greig)

Vitamins, minerals, fish oils… the list of nutritional supplements you can buy keeps growing. Some are worth it, some aren't. We sift the evidence for you

IN 1911, Polish chemist Casimir Funk made one of the most influential biomedical discoveries of all time. He learned that a disease called beriberi affected those who ate a diet of mainly white rice, but not those who ate mostly brown rice. He isolated a chemical from rice bran, showed it could prevent beriberi, and called it "

We now call that compound vitamin B1. It is one of many essential nutrients that the human body cannot produce in sufficient quantities and that we must obtain from food. Casimir's breakthrough led to similar discoveries, including the compounds that prevent scurvy and rickets. In 1920, the British chemist Jack Cecil Drummond proposed dropping the "e" and using ...

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Taming of the bunny rewrote rabbit genome

When humans tamed rabbits, we changed around 100 regions of their genome. The shifts were subtle, but they may have made domestic rabbits less fearful than wild ones.

Pet rabbits will happily sit in their owner's lap, but wild rabbits are famously timid, fleeing at the slightest hint of a human, let alone a fox or hawk. This tolerance for human company was only bred into bunnies recently: about 1400 years ago in southern France. But it was not clear how this worked at the genetic level. Did domestication make drastic changes to a few important genes, or many subtle alterations?

To find out, Leif Andersson at Uppsala University in Sweden and his colleagues compared the genomes of pet rabbits with those of their wild counterparts (Oryctolagus cuniculus ) from Spain and southern France.

No genes had been turned off outright, a process that in theory might have helped reduce fear of humans. "Gene loss has not played a prominent role during rabbit domestication," says Andersson.

Instead, the team found that lots of small, pre-existing genetic variations became more common in rabbits as they were domesticated. Most of these variations involved just one letter of DNA code. All in all, about 100 regions were selected to be different in the domesticated rabbits.

Tamer switch

Rather than affecting the genes themselves, most of the DNA tweaks were in regulatory regions of the genome, which control whether genes are switched on or off. "Wild and domestic rabbits do not differ so much in actual protein sequences, but in how gene and protein expression is regulated," says Andersson.

The genetic shifts were often associated with regions of the genome involved in the development of neurons and the brain. That makes sense, says Andersson, considering the differences in behaviour between domestic and wild rabbits.

"Selection during domestication might have focused on tameness and lack of fear," says Pat Heslop-Harrison of the University of Leicester in the UK. "As a farmer, you neither want the animal to hurt you, nor for the animal to die from stress." Keeping lookout and fleeing from potential predators uses up lots of an animal's energy, which humans would rather see turned into meat.

Because rabbits were only domesticated relatively recently, the new sequences are not all present in all domestic rabbits. As a result, Andersson says escaped domestic rabbits could revert to wild-like forms over just a few generations - assuming they survived in the wild.

Journal reference: Science, DOI: 10.1126/science.1253714

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Moving home? Your microbes will make the trip too

You may forget your toothbrush next time you go away but you can't leave your microbes behind. Millions of bacteria hitch a ride with you, making themselves comfortable wherever you go. Within only a few hours, they will have colonised a hotel room; give them 24 hours and they can take over an entire house.

These are just some of the results from the Home Microbiome Study, the first attempt to trace the path of microbes from our bodies to our built surroundings, and vice versa. "We know that some microbes can increase our weight, we know that some can influence our neurological development, we want to know where those bacteria come from," says Jack Gilbert from the University of Chicago, who leads the work.

The cells of our bodies are outnumbered 10 to 1 by the microbial cells that call our bodies home. Every time we breathe, sneeze or cough we leave traces of these microbial hangers-on. Others are left behind as we shed skin cells or touch surfaces. Given how much time we spend there, most of this microbial shedding is done at home. Despite this, we know surprisingly little about the interaction between our bodily microbes and those in our houses.

Microbial censor

To shed some light, Gilbert and his colleagues mapped the microbial signatures of seven human families, including three that were in the process of moving house. The families came from different parts of the US and were from different socioeconomic backgrounds and ethnicities. Over a period six weeks, the team took repeated swabs of the 18 family members' feet, hands and nose. They also took samples from door knobs, floors, light switches and kitchen counter surfaces, as well as from any pets.

By amplifying and sequencing the genetic material in these swabs, the team isolated more than 21,000 different microbial species. Each family had its own distinct microbial signature that could be used to identify them. This signature was quickly transferred to the family's living space, overwhelming the microbes already there. For example, one of the families moving house temporarily stayed in a hotel room. According to Gilbert, it took just 3 hours for their microbial signature to swamp the room, and less than 24 hours after they moved in to their new house for it to resemble their old one microbially.

Unsurprisingly, microbes transfer most commonly between hands and doorknobs, light switches and kitchen counters, and between floors and feet. Floor samples differed most between families. The smallest microbial variation between people was found between those in regular close contact, like couples, or parents and young children. There was greater variation between separate adults, for example, unrelated flat mates, and teenagers and their parents.

Young children, or people whose gut microbiota have been compromised by antibiotic use, for example, readily "accept" the microbes of others. Household pets were particularly good microbe "donors" – which persuaded Gilbert and his wife to buy a dog to increase the exposure of their family to a greater diversity of microbes, because this has been shown to reduce vulnerability to allergies.

The bugs are watching you

Gilbert says the research could be used to chart people's movement around a house, and monitor their interactions. "We could tell how many individuals live there, and the relationship between them," he says.

He recounts one case where a couple shared their home with a male lodger. Through analysis of the microbial samples from different parts of the house, the researchers could tell that the two men shared a bathroom, but the woman used another – a fact confirmed later by the couple. Theoretically, Gilbert says, analysis of microbial swabs could be used to detect a new relationship or uncover a cheating partner. If a database of people's microbial profiles was ever created, a microbial signature or "fingerprint" could perhaps be used to identify criminals.

In the shorter term, such work could be used to recognise the presence of burglars in the house from an influx of unfamiliar microbes, or recognise alien microbes left on the skin of a homicide victim by the perpetrator – something that Gilbert is now working on in collaboration with the police department of Hawaii.

Journal reference: Science, DOI: 10.1126/science.1254529

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Mapping the web of disease in Nairobi's invisible city

THE Dandora landfill site in eastern Nairobi is a monument to the Kenyan capital's runaway growth; a junk monolith built by the city's 3 million citizens.

On its rim is Korogocho, an informal settlement of tens of thousands of people that, like the dozen other such slums in the city, doesn't officially exist. More than 60 per cent of Nairobi's population live in these makeshift suburbs hammered together from scraps of corrugated iron.

They house the hundreds of thousands of people who flock to the city annually, pulled by the promise of work. By 2025, the United Nations predicts that Nairobi will be home to more than 6 million people, the majority of whom will end up in areas like Korogocho that lack basic amenities such as sewers.

The people of Korogocho rely on natural waterways for washing and waste disposal, and many also keep livestock in close proximity to their living quarters. In the back yard of one of the shacks, James Akoko and James Macharia try to hold a pig steady for long enough to take blood. Akoko, from the International Livestock Research Institute (ILRI) in the city, and Macharia, from the University of Nairobi, are searching for pathogens such as Escherichia coli, Campylobacter and Salmonella, which can infect humans as well as animals.

They are here because the cramped, unsanitary conditions are a breeding ground for such bacteria. If they get into the food chain, the results can be dire. In Swaziland in 1992, infected cattle passed a strain of E. coli to humans that causes bloody diarrhoea – the first such outbreak in the developing world – and the number of people visiting their doctor for diarrhoea jumped sevenfold in a month. Across Africa, diarrhoea is the single biggest killer of children.

By identifying where pathogens originate and concentrate along the food chains, Akoko and Macharia's team hopes to make such outbreaks less likely. "The way you design your city and the way you structure your food system can play into a policy to prevent disease emergence," says epidemiologist Eric Fèvre of the University of Liverpool, UK, who has been seconded to the ILRI to head the international mapping effort. "We're redrawing the map of Nairobi, not based on geography but on the connectedness of animal and human populations, in terms of the bacteria that they share."

To this end, Akoko and Macharia are visiting livestock owners across the city's slums, taking blood and faecal samples from their animals to sequence for microbial DNA. Keeping livestock in the city is technically illegal, so the pair have to rely on a local knowledge rather than official records to locate potential subjects.

At every home they stop at, they ask residents where the animals came from, where they will end up, what medication they are on and whether they have shown any sign of infection. People typically breed a handful of goats, pigs and chickens that they sell for food – sometimes to local people, but often to slaughterhouses that stock the city's main markets and service industry. Pigs and goats are often fed on organic waste coming out of hotels and restaurants. To trace the meat's path, the team also carry out interviews and test samples at abbatoirs, markets and restaurants across the city.

So far, the effort has revealed that Nairobi's food system is massively diverse, with meat and dairy products produced, sold and consumed across socio-economic boundaries. Pathogens that are widespread in poverty-stricken neighbourhoods are also present in high-income areas. They have found high concentrations of E. coli and alarming levels of antibiotic resistance linked to unregulated sales of veterinary drugs.

It is estimated that more than 75 per cent of diseases that have emerged over the past 20 years originated in animals. Often the jump to humans is a fluke – someone has contact with an infected animal, say. But underlying this, says Fèvre, is urbanisation and ecosystem change, exactly the kind of process taking place in Nairobi.

It is a pattern being seen across much of Africa. By 2040, the UN estimates that collectively African cities will be home to 1 billion people, equivalent to the continent's total population in 2009. You only have to look to the current Ebola outbreak to see the impact of pathogens passed from animals.

"If urbanisation really is the process that will result in the next emergence event," Fèvre says, "understanding how those events come to be is really important."

This article appeared in print under the headline "Mapping Nairobi's disease flashpoints"

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Fossil dinosaur nursery includes babysitter's bones

(Image: University of Pennsylvania)

This slab of Cretaceous rock contains the remains of 30 dinosaur infants and one older individual – possibly a babysitter.

Discovered in the Yixian formation in north-eastern China, all 31 fossilised dinosaurs were members of a herbivore species called Psittacosaurus lujiatunensis. This fossil specimen was originally described in 2004, but researcher Brandon Hedrick of the University of Pennsylvania in Philadelphia was inspired to investigate it further after seeing a photo of the find.

Hedrick and his colleagues found that the gathering of young dinos was preserved in such exceptional detail by being suddenly engulfed in material flowing from an erupting volcano. The lack of heat damage on the fossilised bones suggests that this flow was a slurry of water, rock and other debris, rather than lava.

Judging by the size of its skull, the older dinosaur was probably around 4 or 5 years old. This species is not thought to have reproduced until it was 8 or 9 years old, so it seems likely that this older companion was not the parent of the infants it was found with. Hedrick's team believe this could be evidence of babysitting, a behaviour also seen in some modern-day birds.

Journal reference: Cretaceous Research, DOI: 10.1016/j.cretres.2014.06.015

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Today on New Scientist

Robot frogs' sexy signals lure hungry bats to attack

Hunting bats don't just listen out for male frogs' mating calls: they can also use echolocation to detect when the frogs inflate their throat sacs

Experiment tests whether universe is a hologram

A new device searching for fundamental units of space and time has officially started taking data, and could reveal new features of the nature of reality

And now the weather, featuring climate change blame

A new technique connecting individual weather events with the impact of greenhouse gas emissions could bring climate change into everyday weather reports

Your death microbiome could catch your killer

Identity, time of death, cause of death, even whether a corpse has been moved – the body's trillions of microbes could reveal it all

Europe launches two satellites into wrong orbit

Two satellites destined for the Galileo global positioning network may have to burn most of their fuel to get back into formation, or be replaced

Every living thing in the Antarctic Ocean mapped

A new atlas draws on thousands of records reaching back to the 18th century and describes more than 9000 species, ranging from microbes to whales

Vibrations in rings reveal Saturn's inner secrets

Eavesdropping on Saturn's rings has given us clues about surprises in the gas giant's interior

Swap bad memories for good at the flick of a switch

Hate that holiday because you spent your whole time arguing? There may be a way to overwrite your reminiscences if what works in mice works in humans

Sliding stones of Death Valley: Rocky riddle resolved

What causes boulders to glide hundreds of metres across a desert lake bed? Time-lapse footage and smart rocks have helped Ralph Lorenz crack the puzzle

Source of sun's power revealed by ghostly particles

The first detection of neutrinos produced by fusion in the sun confirms that our star has been stable for millions of years

Supernova find backs dark energy and universe expansion

The first evidence that type Ia supernovae are thermonuclear explosions solidifies one of the cornerstones to the discovery of dark energy

Schrödinger's cat caught on quantum film

The patron animal of quantum theory poses for a unique portrait in which the camera and the sitter don't share a single photon – except by entanglement

Fish reared on land replay the transition to four legs

Unusual fish with lungs have developed walking techniques and bodies like those of the ancestors of four-legged animals after being raised on land

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Robot frogs' sexy signals lure hungry bats to attack

Video: Robo-frog sex signals lure hungry bats

Male túngara frogs need to watch their back while wooing the ladies. Their sexy moves, which involve calling out while inflating their vocal sac, are also spied on by predatory bats, prompting them to launch an attack.

By using plastic robo-frogs equipped with artificial air sacs, Wouter Halfwerk from the Smithsonian Tropical Research Institute in Panama and his colleagues have figured out which cues are detected by hungry fringe-lipped bats. They made some of the faux-frogs call while puffing up their sacs, whereas others just made sounds (see video).

They found that bats preferred to attack fake frogs that emitted sounds at the same time as inflating their throat sac. But the bats were not homing in on the sight of the inflated sac: when the frogs were covered with a transparent sphere, the bats were less likely to attack them, suggesting the bats "see" the sac using echolocation.

The experiment is one of the few that documents how complex animal signals can be a disadvantage, in this case by increasing the risk of a frog getting eaten. "Túngara frog courtship signals could potentially be even more elaborate," says team member Ryan Taylor. But the threat of eavesdropping bats may have limited the evolution of a more complex display, he says.

A previous study by the team shows that serenading frogs can send ripples through water, inadvertently helping bats to locate them. Next, the team plans to look at how the combined effect of ripples, calls and pulsing vocal sacs affect bat predation.

Journal reference: The Journal of Experimental Biology, DOI: 10.1242/jeb.107482

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Experiment tests whether universe is a hologram

The search for the fundamental units of space and time has officially begun. Physicists at the Fermi National Accelerator Laboratory near Chicago, Illinois, announced this week that the Holometer, a device designed to test whether we live in a giant hologram, has started taking data.

The experiment is testing the idea that the universe is actually made up of tiny "bits", in a similar way to how a newspaper photo is actually made up of dots. These fundamental units of space and time would be unbelievably tiny: a hundred billion billion times smaller than a proton. And like the well-known quantum behaviour of matter and energy, these bits of space-time would behave more like waves than particles.

"The theory is that space is made of waves instead of points, that everything is a little jittery, and never sits still," says Craig Hogan at the University of Chicago, who dreamed up the experiment.

The Holometer is designed to measure this "jitter". The surprisingly simple device is operated from a shed in a field near Chicago, and consists of two powerful laser beams that are directed through tubes 40 metres long. The lasers precisely measure the positions of mirrors along their paths at two points in time.

If space-time is smooth and shows no quantum behaviour, then the mirrors should remain perfectly still. But if both lasers measure an identical, small difference in the mirrors' position over time, that could mean the mirrors are being jiggled about by fluctuations in the fabric of space itself.

So what of the idea that the universe is a hologram? This stems from the notion that information cannot be destroyed, so for example the 2D event horizon of a black hole "records" everything that falls into it. If this is the case, then the boundary of the universe could also form a 2D representation of everything contained within the universe, like a hologram storing a 3D image in 2D .

Hogan cautions that the idea that the universe is a hologram is somewhat misleading because it suggests that our experience is some kind of illusion, a projection like a television screen. If the Holometer finds a fundamental unit of space, it won't mean that our 3D world doesn't exist. Rather it will change the way we understand its basic makeup. And so far, the machine appears to be working.

In a presentation given in Chicago on Monday at the International Conference on Particle Physics and Cosmology, Hogan said that the initial results show the Holometer is capable of measuring quantum fluctuations in space-time, if they are there.

"This was kind of an amazing moment," says Hogan. "It's just noise right now – we don't know whether it's space-time noise – but the machine is operating at that specification."

Hogan expects that the Holometer will have gathered enough data to put together an answer to the quantum question within a year. If the space-time jitter is there, Hogan says it could underpin entirely new explanations for why the expansion of our universe is accelerating, something traditionally attributed to the little understood phenomenon of dark energy.

Ann Nelson, a physicist at the University of Washington in Seattle, says the Holometer is a novel experiment for probing space on the smallest scales. But even if the experiment finds something, the wider implications for physics are still not well understood.

"It would mean that all our standard assumptions about space-time and effective local theories are wrong, at least when gravity is important," she says.

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And now the weather, featuring climate change blame

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A new technique connecting individual weather events with the impact of greenhouse gas emissions could bring climate change into everyday weather reports

"Well, the record-breakingly hot summer is showing no sign of cooling down. No thanks to us: the heatwave was made 35 per cent more likely by human greenhouse gas emissions."

CLIMATE scientists tend to shy away from assigning blame for extreme weather events like the fictional heatwave described above. But that may be about to change, thanks to a new type of climate study that can connect individual weather events with the impact of human-made greenhouse gas emissions.

So far, these studies have been done retroactively, a year or more after specific extreme events. But the latest techniques are making it possible to examine the role that climate change played in shaping the season that has just past – whether it was a scorching summer or a particularly wet winter, for instance. The ultimate goal is for this to happen in real-time so that climate analysis can become part of the daily weather report.

"Explaining why we're getting the weather we're getting should be part of the job of meteorological offices, as well as predicting it," says Myles Allen at the University of Oxford. Allen was part of a team that carried out pioneering research that examined the impact of greenhouse gas emissions on weather. After a deadly heatwave in 2003 contributed to the deaths of some 70,000 people in Europe, the team used two simulations of the climate – one including human-made greenhouse emissions, and one without – to assess the likelihood of a heatwave of that scale striking where it did, when it did. They calculated that human emissions doubled the odds of it happening (Nature, doi.org/c7hxpt).

Since then, several studies have used similar methods (see "Blame warming?"), but they all have dealt with events long after they have left the public consciousness. Peter Stott of the UK Met Office, who also worked on the heatwave study, and Allen are part of a growing cadre of climate scientists who want that to change.

This year, Nathalie Schaller, also at Oxford, took a closer look at the unusual weather that the south-east of England was experiencing. Record rain fell at the Oxford weather observatory from late 2013 through to early 2014, and there was widespread flooding.

To explore whether climate change was making such precipitation more likely, Schaller and her team ran a similar experiment to Stott and Allen's. They used real-world data to simulate the season that had just passed, then stripped the data of the influence of greenhouse gas emissions and ran the simulation again. The scenario was simulated thousands of times in order to calculate the odds of getting a bout of extremely wet weather at that particular time of year.

They concluded that what was a 1-in-100-year event without global warming had become a 1-in-80-year event. In other words, human emissions made the extreme levels of rainfall experienced in south-east England 25 per cent more likely.

The team's results were published online on 30 April, just two months after the flooding abated. To speed things up even more, a project called European Climate and Weather Events: Interpretation and Attribution (EUCLEIA), led by Stott and funded by the European Union, will test a new system. Instead of waiting for an event to happen, the idea is to incorporate seasonal forecasts, which are done a month or more ahead of time, into the climate models.

"One of the designs EUCLEIA is looking at is to use forecast sea-surface temperatures," says Allen. Sea-surface temperature is an important driver of the weather, and because the oceans change temperature very slowly compared with the air and land, they form a key, predictable component of seasonal forecasts.

In the new set-up, a real-world seasonal forecast driven by data on current sea-surface temperatures will be run alongside a simulated "no global warming" seasonal forecast, in which greenhouse gas emissions have been stripped out.

If an extreme weather event occurs, researchers can look to see if the models predicted it. If it was predicted in the real-world seasonal forecast but not in the scenario which is stripped of emissions, then it was made more likely by climate change – a likelihood that can be calculated.

For now, assigning a share of blame for past temperature anomalies like heatwaves and cold snaps is perfectly feasible, says Stott. Rainfall is more complex to model, though Schaller's study shows it is possible. Hurricanes and tornadoes require specialised models to predict, but Allen says that in theory they could be used to run the same type of experiment.

A main obstacle to bringing this kind of powerful climate modelling into standard weather forecasts is computing power. Models must be run many thousands of times to obtain statistically significant results, which requires expensive supercomputers.

Web-based distributed computing, by which models are run remotely on borrowed downtime on volunteers' personal computers – is one way around the problem. Roberto Mera at the Union of Concerned Scientists in Washington DC is currently using this approach to look at the role of climate change in the record-setting drought now hitting California.

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Your death microbiome could catch your killer

MILLIONS want you dead. No, it's not a Twitter conspiracy, but a battle raging beneath your skin. The cells in your body are outnumbered 10 to one by microbial cells, and like it or not, eventually the microbes will win.

Surprisingly, what happens next has largely been a mystery. Now researchers have made the first study of the thanatomicrobiome – the army of gut microbes that take over your internal organs once you are dead. The results could have applications in forensic science and medicine.

While we are alive, the 100 trillion bacteria resident in our gut work on our behalf. They ease digestion and keep the immune system functioning smoothly, in exchange for a constant supply of food. These "friendly" bacteria adhere to the lining of the gut and keep the microbial villains at bay by outcompeting them.

After we die, however, our gut flora have a party. Dying cells leak carbohydrates, amino acids and lipids, causing a frenzy of microbial feeding and reproduction. The bacteria eventually escape the gut and swarm through the circulatory and lymph systems, spreading to organs that are shielded during life by the immune system.

Understanding how microbes inside a dead body colonise it can help pathologists work out the time of death, where the body has been lying, and how its decomposition could affect the soil and ecology around it. Until now, research in this area has largely focused on the way that insects and microbes from a corpse's environment take up residence in putrefying flesh.

To study how a dead body decays in isolation, Peter Noble at Alabama State University in Montgomery sampled microbes from a selection of internal organs, as "these aren't influenced by environmental conditions", he says. He hoped to discover how long it took gut bacteria to reach each organ after death, and establish which species go where.

Microbial signature

Traditional techniques for identifying microbes rely on growing them in Petri dishes, but gut bacteria are particularly tricky to culture. Instead, the team isolated and amplified bacterial genetic material from cadaver tissues to reveal the microbes present. Their samples came from the liver, spleen, brain and heart of 11 cadavers, between 20 and 240 hours after death.

In the newest cadavers, the researchers found bacteria such as Streptococcus, Lactobacillus and Escherichia coli, which mop up any oxygen left in the tissues after respiration stops. These gut flora are the "usual suspects" you would expect to find in most people.

As the time since death increased, the bacteria present were more likely to be those that can function without oxygen, such as Clostridium strains. For example, some of the cadavers harboured C. botulinum, which can cause botulism, and C. difficile, one of the main culprits in hospital infections. A more unusual strain, C. novyi, turned up in one body (see "Gut bugs united").

Contrary to the team's expectations, there was no predictable pattern of microbe distribution. This was a surprise, says Noble, as he had expected different microbes to thrive in different organs. For example, the team had thought that bile-tolerant species would flourish in the liver, whereas those adapted to iron-rich environments would do better in the spleen.

In fact, there was more variation between individuals and according to time since death than there was between the organs within a single cadaver (Journal of Microbiological Methods, doi.org/t6x).

So does this individual variation mean that we can use the gut flora "signature" of a dead body to identify unknown victims of crime or a disaster, by matching it to bacteria on the unwashed clothes of missing persons?

"The only way to answer this is with a really big sample of cadavers," says Sibyl Bucheli of the Sam Houston State University in Huntsville, Texas, who is also studying the death microbiome. She points out that someone's immediate environment is bound to have a strong influence on the microbes living in and on them, and therefore on their thanatomicrobiome. This means that even though an individual's gut flora might be unique to them, they could also be broadly similar to those of people around them, making it hard to identify a person using bacterial profiling.

Even if it turns out to be impractical as a method of identification, there are other potential uses. Sequencing the DNA present could confirm a suspected bacterial infection, identify an infection when the cause of death was unknown, or even help assess the efficacy of antibiotics in treating an infection, says John Cassella, a professor of forensic science at Staffordshire University, UK.

What's more, "the predictable shift in microbial colonisation of a body means we can use microbes as a clock to estimate how long a body has been decomposing", says Bucheli.

Examining the internal organs could also be useful for bodies where the presence of microbial contamination on skin could confuse the investigation, says Cassella. He thinks it could help determine whether a body had been moved after death. For example, if someone died at home but their body was subsequently dumped elsewhere, the bacteria in their internal organs should have more in common with their home environment than where they ended up.

However it ends up being used, "cataloguing this ecosystem can help us understand how we coexist with microbial communities all around us", says Bucheli. "The microbiome of a cadaver is an unknown data set in biology," she says.

We may not have long to wait to find out whether the microbiome of death holds more surprises: Noble and his colleagues are about to start a bigger investigation, exploring the thanatomicrobiomes of 100 cadavers.

This article appeared in print under the headline "Death: the great bacterial takeover"

Gut bugs united

Lactobacillus (various species)

Found in the gut, vagina and mouth, these bacteria are vital for healthy digestion, helping to break down lactose, the sugar found in milk. L. acidophilus is often present in probiotic yogurt, and there is some evidence that consuming it can help with vaginal infections.

Escherichia coli

E. coli is found in the intestines of mammals. Most strains are harmless, although some are beneficial because they synthesise vitamin K2 (see "A to zinc: What supplements are worth taking?") and protect the gut from pathogenic bacteria; others give us food poisoning or urinary tract infections.

Clostridium difficile

The culprit in many hospital-acquired infections, C. difficile is a normal part of our gut flora, but readily causes diarrhoea if antibiotics have wiped out its neighbours. It is also a common cause of bowel inflammation, which can be fatal in severe cases.

Clostridium botulinum

C. botulinum is infamous for making the neurotoxin botulinum, the cause of the paralysing condition botulism, and the active ingredient in botox cosmetic procedures. It thrives in the anaerobic conditions of a fresh cadaver, before the decomposing skin bursts open.

Clostridium novyi

Found in soil and faeces, C. novyi secretes several necrotising, or "flesh-eating", toxins, and can cause gangrene in people with open wounds, such as intravenous drug users. It thrives in anaerobic conditions.

Streptococcus (various species)

These bacteria are responsible for a range of infections, from sore throats to necrotising fasciitis or flesh-eating disease – in which connective tissue is destroyed. Other non-pathogenic strains are commonly found in and on the body.

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Europe launches two satellites into wrong orbit

ROUND and round and wrong they go. Two European Space Agency navigation satellites launched into the wrong orbit last weekend.

The satellites were meant to be the fifth and sixth in Europe's Galileo global positioning system, a network of 30 satellites expected to be up and running by 2020. They launched from French Guinea on a Soyuz rocket on 22 August, but did not make it to their projected orbits. The orbits were lower than planned, elliptical instead of round, and set at the wrong angle. Worse, it may not be possible reroute them.

"We do not know yet what can be done," says ESA spokesperson Franco Bonacina. The satellites carry 12 years' worth of fuel, but it would take most of that to move them to their intended orbits. "We will have to decide whether it is worth it," Bonacina says.

If they cannot be rescued, ESA may use them for technology demonstrations. "As we say in Italian, we don't want to throw the baby out of the window. We will make good use of them," Bonacina says. In that case, ESA will have to launch replacement satellites to complete Galileo. The next three Galileo launches are planned for December.

This article appeared in print under the headline "Orbital anomaly"

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