Nature Newsblog
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This week the Nature Podcast watches the nervous system at work, discovers how to identify single atoms, and finds malaria's weakness.
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NASA flyby makes for pretty pictures.
NASA's New Horizons mission has swung by Jupiter on its way to Pluto, and taken a slew of photos and measurements.
Read the story here
Tiny transistor uses a single electron to turn off and on at room temperature.
The latest contender to succeed silicon's throne is graphene. It has been used to make a truly tiny transistor that works at room temperature, offering hope for making faster, smaller electronics devices once silicon reaches its limits.
Read more here
Tadpoles use a proton pump to direct tissue regrowth.
Tadpoles can achieve something that humans may only dream of: pull off a tadpole's thick tail or a tiny developing leg, and it'll grow right back — spinal cord, muscles, blood vessels and all. Now researchers have discovered the key regulator of the electrical signal that convinces Xenopus pollywogs to regenerate amputated tails. The results, reported this week in Development, give some researchers hope for new approaches to stimulating tissue regeneration in humans.
Read the story here.
Why is Wikipedia as good as it is? While the debate about precisely what level of goodness that entails has been heated, the free online encyclopaedia offers a better standard of information than many would have expected from a resource that absolutely anyone can write and edit.
Read more here.
Texan takeover may signal changes in the way America generates electricity.
Controversial plans for eight new coal-fired power plants in Texas look likely to be scrapped as part of a proposed buyout of Dallas-based electricity generator TXU Corporation.
Read more here.
Public consultation could suggest killing to control population.
As part of a package of measures to control its spiralling elephant population, South Africa is expected to propose an elephant cull in a document to be released on 28 February.
Read more here
Analysis of fossilized bones suggests milk-drinking mutations emerged after dairy herding.
When did ancient populations learn that drinking milk 'does a body good'? A team of scientists in Germany has tried to answer this question by studying ancient DNA extracted from skeletons thousands of years old.
Read more here
Indonesian physicists have started deploying chains of concrete balls in an attempt to stem the flow of mud in East Java.
For nine months Indonesian officials have been reacting to the torrent of mud that started erupting from a rice paddy in the village of Porong, East Java, with embankments and evacuations. This weekend they began experimenting with a new strategy for controlling the flow.
Read more here
Europe's Rosetta mission is still years from its cometary target, but has sent home some pretty pictures of Mars en route
On 25 February the comet-chasing spacecraft Rosetta used the gravitational pull of Mars to change its trajectory, guiding it on to a future encounter with Earth.
Read more here.
International Polar Year will feature more than 220 separate projects.
With contributions from 50,000 scientists in 63 nations, the International Polar Year, launched today, will be the most far-reaching investigation into the biology and geophysics of the Arctic and Antarctic ever mounted.
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Coatings make all the difference for splashing
A ball dropped into water can make a tiny plop or a huge splash, depending on what it's coated with.
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Ice-shelf collapse offers glimpse of life beneath the South Pole.
Read the story here.
Greener film soundtracks win Academy Award.
As the film world awaits the tearing of envelopes at Sunday's Oscar ceremony, some are already clutching their Academy Awards. Among them are the 12 technicians who, in the name of reducing pollution, have de-silvered the silver screen for good.
Read more here.
Cycling cosmos obeys thermodynamics without ripping itself apart.
It has to be the closest ever shave. Two physicists have proposed that, a fraction of a second before a cataclysm that would destroy space-time itself, the Universe may escape by abruptly collapsing to a virtually empty state that 'resets' it for a fresh cycle of cosmic expansion.
Read more here.
Not all the correspondence to a top science journal contains top science. Some of it is very odd indeed.
Some institutions attract outlandish claims. Curators at London's Science Museum are used to meeting visitors clutching perpetual-motion machines — claims often undermined by the batteries attached to the device.
Read more here.
Muslim artists were 500 years ahead of western researchers.
The complex geometrical designs used centuries ago in Islamic art and architecture were planned with a tiling system that was not discovered in the West until five centuries later, two physicists have claimed.
Read more here.
Dating study suggests it wasn't the makers of the Clovis culture.
For decades many archaeologists have believed that the first Americans belonged to what is called the Clovis culture — hunter-gatherers who lived in parts of North America roughly 13,000 calendar years ago.
Read more here.
Wooden weapons are a first in animal kingdom.
Chimpanzees can hunt with spears, say researchers who have seen wild chimps in the grasslands of Senegal. The innovative apes fashion weapons from sticks to kill bushbabies.
Read more here
Drugs that target common infection might limit spread of AIDS virus.
Drugs that fight genital herpes also significantly reduce levels of human immunodeficiency virus (HIV) in patients infected with both viruses, a new study finds. Most HIV-positive patients also carry the herpes simplex virus, so anti-herpes drugs might help to restrict the spread of HIV.
Read more here
This week the Nature Podcast discovers new lakes under Antarctica, meets some rather clever blue-jays, finds an extrasolar planet and exposes fake science on TV.
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Far-sighted birds plan breakfast the evening before.
They might not pay into savings accounts or keep diaries, but western scrub-jays (Aphelocoma californica) can anticipate and plan for the future, research published in Nature this week shows.
Read more here.
Large lakes in Antarctica speed up ice flow to the ocean.
Lakes under the Antarctic ice pack lubricate the flow of ice off the continent and into the ocean, researchers have found. The discovery has implications for our understanding of how the southern ice sheet will respond to climate change, and how this will contribute to sea-level rise.
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Moving satellites may have caused falling measurements of cloud cover.
Satellite evidence that cloud levels are decreasing could just be pie in the sky. The trend might simply be a result of where the satellites are positioned.
Read more here.
Embraces calm tension between rival gangs.
When British politician David Cameron advocated affection as a solution to antisocial behaviour and petty crime, his speech was mockingly labelled ‘Hug-a-Hoodie’. But no one realized that there is a precedent in the animal kingdom — spider monkeys in Mexico have been observed embracing to avoid gang violence.
Read more here
Local governments crack down on unorthodox views.
Many climate scientists get frustrated with those who don't believe that human activity is causing global warming, but should having such views be a sackable offence? In recent months, two US state climatologists have been asked to stand down from their posts because of it, triggering debate about whether personal views should determine suitability for what many see as an academic position.
Read more here.
It’s not unusual for Noble prize winners to put in an appearance at the AAAS meeting, but this year’s meeting also featured a few Oscar winners as well. In one of the final sessions of the conference, Doug Roble of Digital Domain, filled us in on some of the secrets of designing special effects for blockbuster movies.
Roble listed some of the ways that computer animators try to make their animations look realistic. They use satellite imagery and the latest atmospheric models, he said, and they’re always culling through scientific journals in search of new information. Still, the drive for scientific accuracy has its limits. “It doesn’t have to be totally accurate,” says Roble. “If it looks good, it’s right.”
“I would never ever fly in an airplane that had been designed using my animation,” he added.
Glancing through my notebook on the last day of the meeting, I was embarrassed to see page after page with flowers and odd geometric shapes sketched in the margins. But doodlers need not feel ashamed, says Mimi Lam of University of British Columbia in Vancouver. “Everybody does these things absent mindedly to think,” she says. Right – that’s why I did it. To think.
Lam has been looking at the quixotic carvings on ancient hominid artifacts like the parallel scratchmarks on a 1.4 million year old bone fragment found in the Kozarnika Cave. Are they art? Symbolism? No, says Lam. They’re meaningless doodles, perhaps comparable to a bear leaving his mark on a tree by scratching its trunk. At best, she said, the marks could be a sign of ancient hominids honing their hand-eye coordination.
Well, if those are doodles, I have to hand it to the doodlers. It’s one thing to doodle with pen and paper. It’s entirely something else to go to the trouble of chiseling your doodles in stone.
In a session today on Biosecurity, the debate was on over "dual use" research - work that could be used for good or for evil. How should such work be regulated, and by whom? And what are the most effective ways to ensure that good wins out?
Everyone agrees that education is a big (and cheap) part of the answer: giving new scientists ethical guidance. But according to one questioner in the audience, the issue now is knowing when to start. Graduate school, he says, is about 6 years too late. In the state of Virginia, apparently, kids can take biotechnology classes in highschool. And, he adds, these classes are in the "technologies" department - more commonly known as "shop". As a result, kids with disciplinary problems who are sent off to classes with more hands-on practicals and less bookish homework are ending up doing biotech. Give it a few years, he says, and the juveniles in penitentiary will have had practice splicing fluorescent genes into e-coli and so, presumably, will be all set to become bioterrorists.
Sadly I can't confirm if any of this is true, or a fair assessment of Virginia's biotech efforts (which look admirable to me, from a quick web search). But if there are teachers out there who can let us know if they have a serious problem here, then let us know...
Perhaps more serious problems are apparent in the area of biocontrol... private companies, it seems, are not exactly under the same strict regulation as, say, National Institutes of Health labs. What they're doing with their botulism bacteria is anyone's guess. Other government departments too - including the department of defense - may be doing things with biological organisms that some might term more "offensive" than "defensive" if the details were known.
And if anyone does find out about quesitonable activities - in a colleague, shop student or company worker - it is hard to know, for the moment, who exactly to call about it. That was one question this panel couldn't answer. Though further draft guidelines, expected to be available for public comment possibly as early as this Christmas, should have phone numbers in it. They hope.
Digital imaging makes fakes easier to make, but maybe also easier to spot. News@nature.com talks to mathematician Hany Farid about tracking down falsified photos for science journals and the FBI.
Read more here.
The plenary speech today was a summary of the science in the IPCC’s fourth assessment – a somewhat more sobering counterpart to the light-hearted talk by Larry Page on Friday. It would amaze me somewhat if there was anyone in this room who didn’t already know the conclusions – that the world is committed already to a certain degree of warming, that this warming is very likely due to human-generated emissions of greenhouse gases, and that the impacts of this will include more extreme weather and sea level rise of an unknown but frightening amount. It is, I hope, a case of preaching to the converted. But it’s a message that can’t be hammered home too hard – it only gets better the more it is bashed into peoples’ heads. And it is particularly nice to hear it being done in America.
The AAAS only just this year released its first consensus statement on climate change, saying "global climate change caused by human activities is occurring now, and it is a growing threat to society". It is amazing how long it takes for such things to happen. Perhaps the only thing slower than the planet’s response to climate forcings is mankind’s psychological response: convincing a planet full of people to do something before it’s too late seems to be about as hard as turning a giant ship at sea before it whacks into an iceberg. It will be rather unfortunate if our policy response runs on the kinds of geological time scales that will see Greenland melt and the Antarctic start to turn green.
People have been thinking of adaptation to climate for a very, very long time. As we’re told today in the plenary, Thomas Jefferson observed: “The changes between heat and cold in America, are greater and more frequent, and the extremes comprehend a greater scale on the thermometer in America than in Europe. Habit, however, prevents these from affecting us more than the smaller changes of Europe affect the European. But he is greatly affected by ours.” The lesson - that those un-used to changes in climate are ill equipped to deal with them - is one that we are still learning today, and will learn with some force in the near future.
James Sherley's protest ignited discussions about racism at MIT.
After fasting for 11 days, an MIT biologist ended his hunger strike earlier today. James Sherley gave daily speeches outside of the MIT provost's office to protest the university's decision two years ago to deny him tenure, which he said was due to racism.
Read more here.
Medicine’s long held obsession with the white male has certainly not come to an end, but it does seem to be lessening over the past few years. More and more, we’re finding that therapies originally tested on white men don’t necessarily work well for members of the opposite sex or other races, and scientists have been trying to work out why.
In today’s session called “Genetic Targeting of Drug Therapies”, Esteban Burchard of the University of California, San Francisco discussed differences in how Latino populations respond to the popular asthma medication albuterol. He found that Puerto Rican kids were less likely to benefit from the drug than Mexican children, and has been narrowing in on some of the reasons why.
It’s always striking how tough these studies are, given so many confounding non-genetic differences in environment, diet, and economic class. But when Burchard set out to determine the genetic origins of Latino ethnic groups, he found another complicating factor – how do we really know what race we belong to, anyway?
Burchard found that Mexicans and Puerto Ricans populations differed in the proportion of genetic regions that came from African, Native American, and European lineages. Mexicans, for example, had more regions that were similar to Native American genotypes. But if you looked at individual members of his studies, the variability in genetic makeup was astounding. For example, some participants who insisted that they were Puerto Rican were 100% European, while others were nearly 100% African.
Burchard says he’s developing statistical methods to incorporate that data into his analysis, but one conclusion is clear: “We don’t really know who we are,” he said.
The bioterrorism frenzy in the US tends to focus on glamorous pathogens like smallpox and anthrax. But Jacqueline Fletcher of Oklahoma State University worries about more obscure threats like “Karnal bunt” and “citrus canker”. Though they aren't as well known, unleashing those plant pathogens could cost the US millions in higher food prices and lost trade. And quickly catching a plant disease in the over 1 billion acres of crops, forest, and rangeland in the US won't be easy.
Protecting the nation’s plants against bioterrorism isn’t exactly sexy, and Fletcher’s accustomed to spending a fair amount of time justifying the need to protect plants. Today she started out with a historical approach, highlighting plant disasters from years past, like the Irish potato famine of the 1800’s that sent waves of Irish immigrants to the US. And ever wonder why so many Brits eschew coffee in favor of tea? Thank the coffee rust epidemic in the mid-1800’s that wiped out coffee supplies.
A few things to consider on the 49th running of the Daytona 500 today:
200 miles per hour: average speed of a racecar
0.7 seconds: reaction time of a race driver
144 feet: how long the car travels during that time
Courtesy of Diandra Leslie-Pelecky of the University of Nebraska, author of the upcoming 'The Physics of NASCAR'.
One of the great things about the AAAS meeting is the public events they incorporate to bring in local families. Today is ‘family science day’ here at the San Francisco Hilton, and the place is crawling with kids of all sizes happily wielding geeky science t-shirts and geeky science toys.
Most popular was a Q&A session with the stars of the Discovery Channel show ‘Mythbusters’. These guys -- the beret-wearing Jamie Hyneman and the ebullient Adam Savage – use their experience in special effects and engineering to investigate potential urban legends. They’re best known for doing crazy things like locking themselves in a car and plunging it underwater to see if you can really get out.
But all the fun is really about the scientific method, Hyneman told the rapt audience. “It’s all just general curiosity about the world at large,” he said. “We just want to see what happens.”
Adam, the crazier of the pair, made a serious point when a boy asked him if they would investigate the Bermuda Triangle. “We have to choose a myth that’s actually testable,” he said. “That’s why we don’t do things like the Loch Ness monster or Bigfoot.”
A brief lesson in the scientific method right there.
Who wants a robotic companion? Everyone, said David Calkins of San Francisco State University in a robotics seminar today. But after hearing his talk, I wasn’t so sure.
Calkins listed the many uses that robots could serve in the home. Robots could take over tedious household tasks, for example, and provide a conversation partner that can promise absolute confidentiality – or, as Calkins put it, “the conversation partner who won’t tell your wife you’re cheating on her.” Calkins said when his busy schedule and rental agreement didn’t allow him to keep a live dog, he kept a robot dog instead.
And of course, they’ll be ultra popular among “geeky bachelors who can’t get a girlfriend,” he added. Yeah. You know what he means.
Somewhere in there, I started to become uncomfortable, and it wasn’t just the reference to kinky robot ‘companionship’. Calkins proposed lots of perfectly reasonable uses for robots, focusing on how they could provide 24-hour care for housebound elderly relatives. Clearly it’s a good idea – the robots could be used to manage complicated medication regimens, and could call for help should an accident occur.
But I could imagine how this would play out over time. A robot would be cheaper than hiring human help to care for the elderly, and that could eventually translate into less human companionship for our elderly loved ones. Meanwhile, would we start to use the robot as an excuse not to squeeze grandparents into our busy schedules? “No need to visit grandpa today – RoboNurse will take care of him.”
We’ll soon find out -- Calkins says the technology will be upon us before we know it. “Like the internet, home robots will happen faster than you think, and will quickly become taken for granted,” he said.
Gulp.
Hearing loss in the elderly might not be what you think: it isn’t just the loss of hair cells in the ear, as it is with young kids at rock concerts, or even as many clinicians might tell you when your hearing starts to go. It’s a battery problem. The tissue in the ear that ‘powers up’ the amplifiers of hair cells in the outer ear starts to degrade with age. Oxidants pile up and clog the system. The battery dies. And there goes hearing.
This mechanism was published some four years ago, though it still comes as a surprise to many who hear it today – including doctors. Unfortunately scientists’ understanding of the situation hasn’t yet resulted in any breakthrough treatments. The cells that make up this ‘battery’ can regenerate, so it’s possible that stem cell treatment might be able, one day, to fix the problem. Stem cells would probably also be needed to re-grow hair cells in the ear (which do also die away with age, and don’t grow back). But we’re a long way from clinical trials on any of this. We’ll just have to wait for updates.
In the meantime, a word of advice from the experts on hearing at the conference: don’t listen to your ipod on more than half the volume setting if you listen to it all day (or no more than 80% max volume if you’re just listening for 20 minutes or so). More than that and you may not get to experience age-related hearing loss; your ears may go long before then.
It seems odd at a conference where the grand scale impacts of climate change take top billing to get excited about the global warming impact of eating an 8 once salmon steak. But aquaculture is booming – salmon farming is expected to increase 240 fold by 2030 – and the environmental impacts of these activities are not just “a drop in the ocean”. To assess those impacts, speakers here have been looking at the overall environmental burden of fish production, from the pollution of waters resulting from producing fish food, to the emissions of a plane bound for San Francisco from Alaska with a hold full of fresh salmon. And some of their conclusions give food for thought.
In terms of fish food, for example, Nathan Pelletier of Dalhousie University in Halifax, Canada told the audience that the ‘organic’ label on store-bought salmon is not a guarantee that your fish has tread lightly on the sea. Using organic plant ingredients over non-organic ones does reduce the energy intensity and environmental burden of fish food. But what makes a bigger difference is the proportion of plant components (soy, for example) compared to the animal-derived proteins (like fish oils), and the efficiency of the factory that turns fish by-products into oil and meal. These distinctions do not, at present, show up on the food labels at the supermarket.
And if you want your salmon dinner to have had as little impact on the planet as possible, you need to consider not just how it was farmed and fed, but also how it has been processed and transported. Fresh salmon, says Anna Flysjo of the Swedish Institute for Food and Biotechnology in Goteborg, creates more than twice as much greenhouse gas as smoked salmon. That’s thanks almost entirely to the airplane trip that transports it fast from source to seller. Frozen salmon also wracks up a burden thanks to the energy needed to keep it refrigerated on its boat trip. Smoked salmon in cardboard packaging is the way forwards, she says.
Alternatively you can simply live in Alaska, catch a salmon wild and eat it fresh at source. That would be best. Barring that, I think I’ll skip having sushi for dinner tonight.
I started out the morning at a symposium on the future of internet searching, but the discussion of institutional repositories and language translation algorithms was a bit dry, and I soon headed down the hall for a guaranteed thrill: “Robots – Our future’s sustainable partner”.
Perfect timing – I got there just before University of California, Berkeley professor Robert Full started his talk. Full designs robots that mimic animals of all sorts, and can always be counted upon for cool slow motion videos of insects flying or geckos climbing walls. This time he had a fun video of a cockroach on a treadmill (“The American cockroach,” he explained. “The one that you don’t think you have in your house.”) and a robotic crab playing in the surf, to name but a few.
Full also had a live demonstration of StickyBot – a gecko-like robot with bright orange feet designed to crawl up a glass window. Unfortunately, StickyBot seemed to suffer from stage fright, and kept slipping off the glass.
But despite his push for biomimicry, Full says he isn’ t trying to achieve exact biological replicas, and he won’t be copying evolutionary processes to optimize his designs. Evolution, he said, is a tinkerer without a defined goal, but engineers have finite endgames in mind.
And, he added, robots don’t always have to be as complex as the animals they’re modeled after. The legs of his robot crab, for example, had only two joint motions as compared to the biological crab’s nine. “Crabs do a lot of other things,” he said. “They fight with one another, they mate with one another.
“Robots don’t do that… yet.”
In late December 2004, the world was riveted by the horrible news coming from the Indian Ocean tsunami. And a lot of people missed the news that - for a few days at least - there was a reasonable chance that an asteroid called Apophis was poised to devastate even more of the globe in the year 2029.
Later calculations showed that Apophis will miss Earth that year, but a slim chance remains it could hit in 2036. And even though that probability is expected to go away with further studies, politicians and governments ought to sit up and take notice, says Rusty Schweickart.
Schweickart is an Apollo astronaut and a key player in the Association of Space Explorers, which is trying to get the United Nations to take a leading role in figuring out who should lead in deflecting any potential asteroid threat, and when. At the AAAS meeting today, Schweickart showed a map of the possible places on the globe that Apophis might still hit in 2036. The potential impact area extends in a line arcing from Kazakhstan over east Asia, extending along the Aleutian islands and down the Pacific, crossing Central America on the northern border of Costa Rica and eventually petering out in the Atlantic just off Africa.
The map vividly illustrates how many countries will be panicking if an asteroid is indeed ever found that looks like it will definitely hit. Schweickart will be speaking to the UN committee on the peaceful uses of outer space next week, in an effort to get some protocols in place. It's not simple to figure out who ought to do what in the face of a planetary catastrophe, he notes. Within the US, agencies such as Homeland Security and FEMA are typically charged with public safety.
"And do you really want FEMA in charge of this??" he asked.
Today’s session on infant memory closed with some sobering news for mothers with diabetes – get your sugar under control, or your child may experience long-term memory difficulties for years to come.
When diabetic mothers experience abnormal blood sugar levels, the developing fetus feels it, too. As a result of the metabolic flux caused by rapidly changing sugar levels, the fetus may be chronically starved for oxygen and may also redirect iron away from the developing brain and other organs to the blood. This, said Tracey DeBoer of the University of California, Davis, can be particularly harmful to the hippocampus – a region of the brain that’s critical for memory
DeBoer and her colleagues tested long-term memory in infants born of diabetic mothers. One-year olds were taught to put a toy car in a container and push a car down a track. The investigators tested recall immediately after teaching infants the tasks and ten minutes later. Children who were born with iron levels in their blood – a sign that they’d experienced abnormal sugar levels in the uterus -- performed just as well as the control group when asked to immediately recall the task. But after the ten-minute delay, they struggled more to remember what they’d been taught.
DeBoer followed up with the same kids two years later, and retested them with age-appropriate tasks that were more complicated and had to be remembered for a longer time. Again, children born with low iron were less successful at retaining memories of the learned task . The greater the iron deficiency at birth, the worse their performance.
On the bright side, DeBoer said that children born to mothers who kept their blood sugar under tight control had normal levels of iron at birth and passed their tests with flying colors.
Larry Page told the conference today that his invention (PageRank, the thing that drives Google) holds a lesson for science funders…
He started his whole project by accident. He decided to map out the links of the internet, thinking it would take “about a week”, and a few years later had a pretty nice dataset. And, oh, by the way, maybe it would be useful for searching too. “It was completely random – it’s a great example of pure research and why we want to do it.”
“When you have basic technologies, you find interesting things to do with them. If you’re lucky it turns into something big.” Funding agencies take note.
It is amazing what we can do with mind-computer-body interfaces these days. I have read the stories about people moving a cursor on a computer screen using only the power of their thoughts. I have edited stories about modern prosthetic arms that move when the wearer thinks about moving, and the re-wiring of nerves so the user can regain ‘feeling’ from their lost limb. I know, intellectually, about all these things. But I’d never seen a video of someone miraculously regaining movement from a lost or deadened limb. Suddenly now it seems simultaneously more real, and more like science fiction, than it did before.
In today’s session on “smart prosthetics” (the latter part of the same session Sarah wrote about here) we were shown video clips of paraplegics opening peanut butter jars, blow drying their hair, and even walking down the aisle at their own wedding, thanks to implanted devices that, when turned on by a radio-transmitting external switch, stimulate a predetermined bunch of nerves. Simply press a button to activate the hips, knees, leg and back muscles of a woman with no control over her legs, and she can stand up. Turn the switch off and a man sitting upright crumples like a puppet with cut strings.
Electronics can be used to bypass a break in the spinal cord, helping the brain to talk to the muscles, a wheelchair, or a computer cursor. As long as the mind still functions, it seems, its connection to the body can be repaired - or simply bypassed altogether (see John Donoghue’s lab for more info on how the brain turns thought into action, and Hunter Peckham’s lab on controlling muscles externally).
There is obviously a long way yet to go, and we do not have the fine control that can turn complex thoughts, above and beyond ‘clench hand’ or ‘bend knee’ into complex actions. But we’re getting there. The researchers in this room dream of allowing a paraplegic to play Rachmaninoff on the piano, without the watcher ever knowing they were once disabled. We’re not there yet, but after seeing these films, I’m willing to join in with the dream.
Perhaps the greatest advantage of the AAAS is the way it brings together scientists – and journalists – from across all the disciplines. I know it sounds cheesy, but this really does bring a new and refreshing light to old topics. Talking to a particle physicist over a glass of wine about recent news events, for example, gave me a new perspective on climate change. In his line of work, “certainty” is a much firmer thing than it is in the Earth sciences. No one would claim to have found a particle if they were only “greater than 90%” sure that they had observed it. Yet that’s the IPCC level of certainty that climate change is being caused by mankind – an announcement that was heralded in the press as being really, really quite sure indeed, with headlines from “climate change pinned on mankind” to “It’s all your fault!” splashed across the newspapers. Particle physicists would rather be 99.99994% certain (that’s 5 sigma for those who know about such things) before making such firm statements. Of course there isn’t a precautionary principle when it comes to the existence of, say, the Higgs boson, nor is our children’s future riding on the ultimate energy of the particle that ‘gives things mass’. So perhaps the comparison isn’t really fair. But it gave me pause for thought.
Hurrah for the plastic brain! At a session this morning on neural prosthetics – smart devices that restore lost nervous system functions – Michael Merzenich of UCSF praised the brain’s remarkable plasticity. Merzenich was describing the way the brain actively cooperates in recovery following a cochlear implant to restore hearing. Despite what Merzenich calls fairly primitive technology, the brain in many cases is able to interpret speech from the limited information it receives.
Neural prosthetic technology is developing fast though. In addition to cochlear implants, researchers are working on retinal implants and new implantable stimulators for bladder control. The latter is particularly important for patients who have had spinal cord injury as loss of bladder control leads to infection and kidney problems. According to William Groat of the University of Pittsburgh, who is developing an implant to stimulate the pudendal nerve, the bladder control pathway is actually a fairly simple system. Imagine, he says, how much harder it gets if you are trying to restore hand or arm function to such patients.
This is exactly what Hunter Peckham of Case Western Reserve University is doing. His team is using multiple-channel implants to restore certain movements to spinal-cord injury patients. As Peckham explains, the act of standing requires activating 8 muscles, walking another 16 or more, while coordination of the stimulation becomes much more complex. An implant for bilateral hand control involves 12 electrodes for stimulating nerves and another two for recording, all of which are connected to a single control device. The amazing recovery of function by many of these patients – allowing one patient to sit erect or to roll over, and yet another to compete as a sailor – is heartening. But as the movements become more complex – and the patients’ expectations become higher – the sheer number of electrodes involved will rise rapidly. What sort of networked implant might be needed to move this amazing research to the next level?