New Scientist (August 31, 2002)

New Scientist Vol 175 No 2358

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A new way to tackle malaria Sperm rememberthe way Airbags could conquer asteroids Howmammalsgothot Building houses out of sewage The radio that made itself Martian time capsule

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EDITORIAL

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What do galaxies, stockbrokers and style gurus have in common? A set of numbers that describes everything they do. Does nature's hidden program mean we're all deeply predictable, asks John Casti 28 FIRES FROM HELL

For some countries, extinguishing underground fires could do more to tackle global warming than anything else. But it's easier said than done, as Eugenie Samuel discovers 3ft DANGEROUS LIAISONS

Species have been happily swapping genes for millennia. What happens when the transgenes join in? Bob Holmes finds out 38 TOXIC TIDE

Pet lovers are spreading a deadly parasite that's devastating California's sea otters. ElinKelsey reports ft2

CONFERENCE REPORT AMERICAN CHEMICAL SOCIETY

Wine tastes better in big glasses Sensing single molecules

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IN BRIEF

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"People who had a positive perception of ageing lived 7.5 years longer on average than those who subscribed to a negative stereotype" Theodore Roszak says we need to lighten up about getting old, page Vt

Vaccination is the best way to tackle infectious diseases. So why are vaccine development and distribution in such a woeful state, asks Rino Rappuoli 25 LETTERS

GM maize in Africa; like human, like banana; a Universe withoutstars 26 ESSAY

By 2050 there will be three Americans over the age of 60 for every one below the age of four. A cause for celebration, declares Theodore Roszak ftft THE WORD

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How the Scots put the boot into Irish whiskey - helped byan Irishman ft8 BOOKS Felice Frankel's book about her beautiful science photography. Plus: how to save the planet - a guide that never gets to the point; the lore of American bison 50 POLITICS Washington Diary: domestic terrorists; dining modestly at the World Summit 5ft ENIGMA

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31 August 20021 NewScientist 11

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IN A typical year our planet suffers 18 major earthquakes and one great quake measuring 8 or higher on the Richter scale. Predicting when or where the next one will happen remains impossible, but by now you'd think we would at least have a clear-cut system for identifying the faults that cause them. Not so. A blistering row over whether a convention centre in Salt Lake City, built for this year's winter Olympics, is or isn't straddling an active fault reveals just how uncertain is our knowledge of the ground beneath our feet (see page 5). Faults and cracks buried under the roads and parking lots of cities are the most difficult to map, yet the most important to know about. Measuring tiny variations in gravitational and magnetic fields can help. And in Los Angeles in recent years, scientists have made progress by placing scores of seismographs in homes and buildings, and analysing the way they detect waves from controlled underground explosions. None of these options is exactly cheap, however, so the world beneath many cities in earthquake zones remains woefully underexplored. Where it isn't, the sparse knowledge we have has all too often been won the hard way. Breakthroughs in seismology have a nasty habit of coming after the event. In the igth century, scientists suspected earthquakes were caused by

local phenomena. It took the terrible San Francisco quake of 1906 to give rise to the famous "elastic-rebound" theory. Years later, the dogma took hold that quakes only occur where the ground is visibly fractured - till an earthquake in fracture-free central California in 1983 revealed this to be untrue. Now we know that "blind" thrust faults buried deep underground can also wreak havoc. And in 1994, it took 69 deaths and $13 billion worth of toppled buildings and bridges in Northridge to confirm that these thrust faults can shake the ground more vigorously than the more common "strike-slip" faults Can we break this painful pattern of after-theevent discovery? In the US, many researchers are backing an ambitious project called EarthScope to do for the geo-sciences what the human genome project has done for biology. One of its aims is to move 400 hi-tech seismographs across the US over a ten-year period. Another is to set up hundreds of sophisticated global positioning receivers and strain meters to chart the tiniest ground movements. The result will be an inverted telescope designed to image with unprecedented detail the Earth's "inner space". The funding remains precarious. It shouldn't be. In the meantime, the row in Utah looks set to run and run with no resolution in sight. Let's hope it doesn't take an earthquake to provide one.

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IF THE rich countries of the northern hemisphere thought they wouldn't ever have to think about tropical diseases, then they are now getting a conscience call. This week, we report a case of malaria near London's main airport (see page 9). And, more serious, the mosquito-borne West Nile virus is spreading faster than ever in the US. The virus had never been seen in North America before 1999, when it killed seven. This year there have already been n fatalities, and infections as far north as Maine and Minnesota. Why are tropical diseases appearing in new places? The malaria case in London was probably caused by an infected mosquito that had hitched a ride on an intercontinental flight. West Nile virus most likely reached the US the same way. Naturally enough, the US Centers for Disease Control has boosted its funding on the virus, up to $30 million so far this year - more than was spent in the previous three years combined.

That's good. But new cases of tropical diseases in the temperate north remind us how little effort has gone into tackling them. There is no tested vaccine against West Nile virus, for example, even though it may be relatively easy to make one. It has never been thought a profitable area for research; we don't even know how many people die from the virus annually in Africa and Asia. But we do know that over a million people die from malaria each year. And we know that only 10 per cent of the funding for infectious disease research goes on the diseases that cause 90 per cent of the deaths worldwide, because they occur in poor countries. This year has seen the launch of some new projects, including the Drugs for Neglected Diseases Initiative from Medecins sans Frontieres, to try to stop profit alone determining which diseases are targeted for research. But far more support is needed from rich nations now experiencing some tropical diseases first-hand.

31 August 20021 New/Scientist 13

International news and exclusives

This week Good legs teach bad legs to walk With the help of a surgical implant, paralysed legs take their cue from their able partners to stand, walk and sit DUNCAN GRAHAM-ROWE

TWO men paralysed on one side of their body can walk again, thanks to an ingenious implant that uses signals from a healthy leg to control a paralysed one. Both men, aged 47 and 64, had been paralysed by strokes. Previously neither could walk unaided. But after sensors were placed over certain muscle groups on the healthy leg and stimulators implanted in the paralysed leg, they can now walk, stand and sit. The unique therapy allows a patient to move their paralysed leg in a natural way without being aware that they are doing it, says Wenwei Yu, who developed the technique at Hokkaido University in Sapporo, Japan. But it could be another five years or more before the technology becomes available, he says. In Yu's system, muscle sensors monitor signals from the patient's able leg. These are used to trigger pre-programmed electrical impulses in 11 electrodes implanted near nerves in the paralysed leg. This lets the paralysed leg do what the patient wants it to do - by taking its cue from the good leg. Producing movement in limbs by electrically stimulating muscles or nerves is known as functional electrical stimulation. One of the difficulties of using conventional FES, says Paul Taylor, a clinical engineer at Salisbury District Hospital in Wiltshire, is overcoming "spasticity " - involuntary muscular spasms normally suppressed by the brain. "So even if you had appropriate signals in the appropriate muscles it may not behave normally,"he says. "There will also be stiffness, the muscles will be weak and activity

4 ^NewScientist^ 31 August 2002

from other muscles might be working against what you're trying to do," says Taylor. Another problem with conventional FES, says Yu, is that patients have to activate the electrodes using their upper body, either through hand-held switches or sensors in their arms. A certain wrist action, for example, could make a leg move. But this is far from practical, as they may want to make that same arm movement for other reasons. And while researchers have been trying out FES for many decades, much of the work on legs has focused on paraplegia, where both legs are paralysed. But hemiplegia, where only one leg is paralysed, is far more prevalent. By taking advantage of the working leg to control the paralysed one, Yu avoids the problem of using the upper body to activate the electrodes. And he avoids any spasticity by tuning the electrical stimulations and their timing so that the muscles work in concert with each other to produce smooth coordinated movements. Not only that, but the electrical stimulation itself has a therapeutic effect, preventing the leg muscles from getting stiff. Gerald Loeb, an expert in FES at the University of Southern California in Los Angeles, says Yu and his team will have to ensure their technique is safe because many hemiplegic people are elderly. One fall and they could break a hip. Yu acknowledges these dangers but says his system uses a learning program that tailors itself to the individual patient's muscle contractions. This means it can get almost perfect recognition of the patient's intentions, which should reduce the risk of falling. •

The new implant could help some stroke patients to walk agair

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In this section • Pig-cell transplant success, page 7 • Collision threat from dead satellites, page 8 • Cows like a side salad with their clover, page 9

0lympic palace on shaky ground? A CONVENTION centre's extension, built for the Winter Olympics in Salt Lake City earlier this year, straddles an active earthquake fault line according to geologists in Utah. They say their warnings weren't heeded when the extension was built and that if a quake does strike, the building could be torn in two. Roy Shlemon was called to the Salt Palace construction site to give a second opinion in 1999, after local geologist David Simon found what looked like a fault line. By digging trenches and examining the soil layers, they found that the ground had fallen by 1.5 metres between 7000 and 8000 years ago, and that there had been several more recent, smaller shifts. "There's no doubt in my mind that this is an active fault," says Simon. In Utah, as in many places around the world, it's illegal to build across a fault known to have been active in the past 10,000 years. While most of the damage during a quake is caused when the ground shakes, buildings stand no chance if the ground beneath part of the foundation drops by say a metre. But relocating Salt Palace would have cost millions of dollars, so the county planning authority sought further opinions. Consultant Les Youd said he believed the slip might have been caused not by a quake but by soil liquefaction, brought on by a tremor in a known fault line nearby. Movements in a layer of silt about 30 metres down could have forced slabs of land to slip sideways downhill, he says, creating the appearance of a vertical shift in the soil. Because the water table has dropped since then, a future quake wouldn't cause the same problems. In 2000, an independent consultancy firm based in California concluded that there wasn't enough evidence of faulting, so the building was completed, with steps taken to strengthen the foundations. In Youd's opinion, it was the right decision. But Shlemon and Simon disagree. Simon points out

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that the slip is linear and unbroken, it lines up with a known fault that is six blocks further north, and branches into multiple cracks near the surface - all evidence more consistent with faulting than sideways spreading. "The lateral spread hypothesis just isn't

"In Utah, as in many placesl it's illegaltobuildacrossafau.lt known to have been active in the past10,000 years"

physically possible," says Simon. Shlemon will present their views at an environmental catastrophes meeting in London this week. The two geologists are concerned that financial pressures might have been a factor when Salt Palace was given the go-ahead. "If you get enough [scientific] opinions, eventually you'll get the one you need," says Simon. He and Shlemon argue it would have been better to play safe. "If you have a plane and there's a 50:50 chance the

wing will come off, you don't fly," says Shlemon. Youd agrees that further studies should be done to find out where the fault line just to the north actually stops. "We still don't know where it goes. Finding these faults should be a high priority," he says. But there are no plans to do that, says Gary Christenson from the Utah Geological Survey. An imaging technique called seismic reflection profiling could be used, but it's expensive. And if a fault were found, demolishing buildings would be very unpopular, Christenson points out. "That would be impossible here." Nicola Jones •

The next quake could spell the end for the Salt Palace convention centre

Mystery surrounds bizarre mental disease afflicting Britain's birds

in the numbers of sparrows and starlings across Britain. But the mystery disease is unlikely to be the cause, because the only cases so far have been in Scotland. "We've not found an answer to the decline, but we've found a new mystery,"

BRITAIN'S sparrows and starlings are dying from an unknown disease. While tests

bizarrely. Now the swollen brains of birds that died of the disease have been

have ruled out West Nile virus, which is

analysed for the first time, because of

numbers, but it's certainly there and it

transmitted by mosquitoes and has killed

fears it might be West Nile.

might be the tip of the iceberg."

several people in the US this year, researchers have no idea what is to blame

of the related viruses," says Tom

or if humans could be affected. Ornithologists in Scotland have

"I'm glad to say it wasn't that or any

says Pennycott. "We're not talking big

He may have found other clues about the cause of the decline. In work not yet published, Pennycott found the salmonella food-poisoning bacteria in

Pennycott of the Scottish Agricultural College's Veterinary Science Division in Ayr. But so far his team has drawn a

two-thirds of the dead sparrows brought

neurological condition since 199ii. Young birds with the disease can't fly, instead walking round in tight circles, doing

complete blank when it comes to

to him. A paper in this week's Nature,

identifying the disease. Conservationists were already

however, blames the decline on changes

somersaults and twisting their heads

concerned about the widespread decline

food for birds in winter. AndyCoghlan •

reported several cases of a strange

in farming practices that mean there's less

31August2002|NewScientist|5

60 SECONDS WORLD SUMMIT Going nowhere fast Weekend talks aimed at resolving 411 outstanding issues in the summit's final text settled just 10. Half the unresolved issues concern world trade, aid and international debt, with the world's rich and poor at loggerheads.

Transatlantic tiff' The British government says it is still trying to persuade the US to drop its veto on firml timetabled targets being set at the summitl covering issues such as providing sewer systems, boosting renewable energy and halting biodiversity loss. Stealth bombers are invisible to radar, but a frequency foul-up could blow their cover

Coming soonl the not-so-stealthy bomber heading for a TV near you BARRY FOX

FOR most of us, TV interference means nothing worse than a few blips on the screen. But for the US Air Force it has become a billiondollar problem. That's because the USAF>s flagship aircraft, the stealth bomber, could soon be announcing its supposedly secret arrival in war zones on ordinary TV sets. According to the military journal

jane's Defence Weekly, the radar systems on board the USAF's B-2 stealth bombers will interfere with satellite-based communications services that are being planned for the end of the decade. The bombers' radar signals are so powerful they could even fry civilian electronics. The problem centres on the "Ku-band" frequencies, which stretch from 12 to 18 gigahertz. Communications and TV satellites

DISPATCHES BUBBLE TROUBLE The Norwegian government has rejected a proposed experiment to pump tonnes of liquid carbon dioxide into the waters off its shores. Some researchers believe dumping C02 in liquid form deep in the ocean will help reduce the build-up of the gas in the atmosphere. In cold, deep waters, CO, should stay liquid and not bubble back up to the surface, they say.

6|NewScientist|31August2002

TANGLED WEB BT saw its dream of earning royalties from all the world's Internet service providers (ISPs) crumble last week. The British telecoms company claimed it owned a patent covering hyperlinks. In the hope of setting a precedent, it sued the US-based ISP Prodigy Communications. But the US District Court in New York has thrown the case out, saying Prodigy does not infringe the patent.

SMALLPOX DEFENCE Israel has begun vaccinating 1500 health workers against smallpox amid concern that it could be the victim of a retaliatory strike if the US attacks Iraq. Ido Hadari from Israel's Ministry of Health says the people being vaccinated are those who will help to administer the vaccine to the public should it be needed. A further 150,000 emergency workers may also be vaccinated.

have until now only beamed signals down to Earth at frequencies between 10 and 13 gigahertz, leaving the upper reaches free for radar. So the first stealth bombers, in the early 19805, used radar in some of the empty Ku-band frequencies. But the ever-increasing numbers of communications and TV satellites are rapidly eating up spare frequencies between 10 and 13 gigahertz. So the International Telecommunications Union is now allocating them higher Ku-band frequencies. For obvious reasons, the Pentagon does not publish the Ku-band frequencies it uses. But it has admitted that after 2007 there will be a clash between the transmitters on the stealth bomber and new commercial satellite services. It's about as un-stealthy as an aircraft could be. The USAF has two fixes to choose from. It can change the frequency of its radar, which risks making it less accurate. Or it can replace the plane's radar antennas with steerable ones that can be pointed away from population centres, jane's Defence Weekly says either option will take ten years to implement and cost at least $1 billion. •

TrickledOWn? UN cities chief Anna Tibaijuka said that in most African cities "the poor pay 5 to 10 times more than the rich forwater".The rich are connected to subsidised public supplies, while the poor have to buy from street vendors.

Joining hands One idea to emerge from the summit is that of formal partnerships between industry, government and citizens'groups to meet summit targets. UN officials are said to have lined up almost 200 partnership projects in everythingfrom city water supplies to saving great apes. The plans have been fiercely attacked by critics who claim the conditions attached favour big business.

Concerned capitalists Agroup of top industrialists calling themselves Business Action for Sustainable Development said they were in favour of national laws to make them more accountable. "It is a myth that we want a Wild West lawless society," said Lord Holme of the International Chamberof Commerce.

Spot the delegate Fearing bad publicity, the British government is keepingthe size and composition of its delegation a secret, even from its own delegates, say insiders. One observer likened the system to the cell network ofaterrorist group. Many of the delegates have also been gagged. "I am only allowed to talk to you about things the British delegation is not interested in - like football," said one.

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Pig-cell transplant hope for diabetics STEPHEN LEAHY AND MICHAEL LE PAGE

A 17-YEAR-OLD girl with diabetes has not needed to take insulin or any other drugs for more than a year after being given cells from newborn pigs, claims the Mexican team that performed the transplant. If confirmed, it represents a rare success for animal-to-human xenotransplantation. However, five other teenagers given the cells have only had their insulin requirements reduced by half, and another six didn't benefit at all. Sceptical researchers have pointed out that young people with diabetes sometimes start producing insulin again, and that the Mexican team has yet to prove that the insulin is coming from the pig cells. "I am not convinced," says Camillo Ricordi of the University of Miami, former president of the International Pancreas and Islet Cell Transplantation Association. Hundreds of millions of people worldwide have insulin-dependent

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or type I diabetes, caused by the death of the insulin-producing islet cells in the pancreas. There have been many attempts to cure it by transplanting pancreases or islet cells. In the past three years, up to 80 per cent of people given human islet cells taken from corpses have still been making enough insulin in their own bodies a year later. But there is a severe shortage of human islet cells suitable for transplantation. Worse, all those who have received transplants will have to take immunosuppressive drugs, with all their nasty side effects, for the rest of their lives. To get around the need for immunosuppressive drugs, Rafael Valdes of the Children's Hospital of Mexico transplanted Sertoli cells from the testes of newborn pigs along with pig islet cells. Previous studies have shown that Sertoli cells have a special marker on their surface that makes attacking immune cells commit suicide. First, Valdes implanted two

3-centimetre-long stainless steel tubes just below the skin. Two months later, when tissue had grown around and into the tubes to provide an ample blood supply to the area, the Sertoli cells and around a million islet cells from week-old piglets were inserted. No immunesuppressing drugs were used. The patients lost a large number of the cells early on due to rejection, but the immune response lessened over time, says David White of the Robarts Research Institute in Canada, who collaborated with Valdes. The findings were presented this week at a meeting of the Transplantation Society in Miami. The trial did spark concern about "rogue" transplanters operating in "unregulated" countries, says transplant surgeon David Cooper of Harvard Medical School. But Cooper says he inspected the facilities of Diatranz, the New Zealand company that supplied the pig islet cells, and found them to be excellent. Although the Food and Drug

Administration has no jurisdiction in Mexico, Cooper would like Valdes to apply for FDA approval for the new trials he plans. "If he did that, everyone would be happy," he says. There are also worries that xenotransplantation could allow porcine endogenous retroviruses (PERVs), which lurk in the pig genome, to leap to humans. But Ricordi says there's no evidence of this in the hundreds of patients worldwide who have been (unsuccessfully) treated with pig islet cells so far. One of the major hurdles with xenotransplantation is that the immune system attacks animal cells even more vigorously than cells from non-compatible people. But PPL Therapeutics of Edinburgh announced last week that it had removed both copies of the gene responsible for provoking the most severe immune attack from pigs (see New Scientist, 12 January, p 7). Transplants from these pigs should have a better chance of surviving. •

31 August 20021 New/Scientist 17

SOUNDBITES CC We do not accept that human society should be constructed on the basis of the savage principle of the survival of the fittest. JJ South African president Thabo Mbeki openingthe World Summit in Johannesburg (26 August)

U The evidence shows that the Japanese troops used bacteriological weapons. JJ

It's not just astronauts who'll be endangered by space junk but people on the ground too

Dead satellites haunt GPS DUNCAN GRAHAM-ROWE

DEFUNCT global positioning satellites are being junked in graveyard orbits in which they risk colliding with their active sister satellites, according to research commissioned by the US Air Force. The errant spacecraft could pose a threat to the Global Positioning System in decades to come, as well as other satellites in low-Earth and geostationary orbits. Engineers say the risk of a collision between dead and active

Retired satellites are on collision course »QPS operating zone •Degraded GPS disposal orbit after 20-W) years • GPS disposal orbit •Degraded GPS disposal orbit after 160-180 years

81 NewScientist 131 August 2002

GPS satellites is increasing all the time. And even without a collision, the service is in jeopardy as a dead satellite that drifts within a few hundred metres of an active satellite might obstruct its transmissions. The problem, according to engineers at the Aerospace Corporation, in El Segundo, California, which carried out the research, is the long-term influence of the Sun and the Moon. When fuel on one of the GPS satellites is about to run out it is tucked away in a "disposal" orbit 500 kilometres above the active GPS fleet of 24 craft, which orbit at an altitude of about 14,000 kilometres. "For a good period of time the [disposal] orbit can remain stable," says Anne Gick, one of the authors of the company's study. "But the Sun and the Moon's gravity perturbs the orbit in the long term." The result is that their orbits become increasingly elliptical (see Diagram). There are currently 16 retired GPS satellites in disposal orbits, and each year there are two more. To make matters worse, the next generation need an extra launch vehicle stage, and these too will be dumped in the disposal orbits. Gick, and colleagues Alan Jenkin and Chia-Chun Chao, have a way to reduce the threat from the next-

generation craft, which will be much more manoeuvrable than the existing ones. They suggest using their engines to reduce any eccentricities in their disposal orbits from the outset, so it will take much longer- hundreds of years - to become unstable. But this option isn't available for the majority of the satellites already in service: most are simply not capable of making the necessary manoeuvres. And a spokesman for the GPS Program Office, also in El Segundo, says the extra fuel used to make a disposal orbit more circular could lower its final disposal altitude. Those that have already been ditched are also beyond help. "There's nothing we can do about them," Gick says. That's because a satellite's fuel is dumped as soon as it is placed in a disposal orbit - to avoid an explosion in the event of a collision. After the fuel is dumped, there's no way the craft can be moved, the team reveal in the latest edition of the Journal of Spacecraft and Rockets (vol 39, p 532). In theory, mission planners could have foreseen this problem 30 years ago when GPS was first launched. "But I'm not surprised they didn't know this," Gick says. "It's a very complicated problem." •

Judge Koji Iwata of the Tokyo District Court admits germ warfare killed many in China - but ruled that the survivors had no right to compensation (Japan Today, 27 August)

Hit would be possible to carry yourown child in the same womb, donated by [your] mother, as you developed in.JJ Mats Brannstrom of Gothenburg University, who has just carried out the first womb transplant in mice and plans to try it in humans (Society of Endocrinology press release, 21 August)

It I'd stake my life that there won't be a living thylacine in 10 years. JJ Janette Norman of Australia's Museum Victoria dismisses attempts by a team in Sydney to bring back the extinct Tasmanian tiger by cloning a preserved specimen (AFP news, 22 August)

(C There does have to be some kind of a public message that stealing is stealing is stealing. JJ John Malcolm of the US Department of Justice warns that people who copy files overthe Internet may soon face prosecution (Cnet.com, 20 August)

11 This doesn't happen very often in Northallerton.JJ Siobhan Cowton, 14, on being struck on the foot by a meteorite outside her home in a North Yorkshire town (The Daily Mail, London, 27 August)

www.newscientist.com

Jet-setting mozzie blamed for malaria case A MYSTERY case of malaria near London's Heathrow Airport is being investigated by officials, who suspect the patient may have been bitten by a "stowaway" mosquito. The person, who works near Heathrow and has been successfully treated, has not recently been to any country with malaria. Officials from the government's Public Health Laboratory Service are trying to establish how it happened. "It's either from a mosquito or from blood [from a hospital]," says David Warhurst of the PHLS's malaria lab at the London School of Hygiene and Tropical Medicine. "If we get any odd cases we can't explain, we do an investigation to see if it's imported or someone who's arrived with malaria on a plane." Warhurst says that the last British cases traced to a stowaway mosquito were in July 1983, in a village 12 kilometres from London's

Gatwick Airport. A pub landlord collapsed with hallucinations, and a motorcyclist who had passed through the village also contracted the disease. "It seems likely it was the same mosquito," says Warhurst. There have also been "clusters" of cases around Amsterdam's Schiphol Airport and Charles De Gaulle Airport near Paris. But cases traced to stowaway mosquitoes are rare, as the cabins of all aircraft leaving malaria-infected regions have to be sprayed with insecticide. In a 1991 report forthe PHLS, Warhurst warned that global warming could make it easier for the mosquitoes to survive the English climate, although they shouldn't live for more than a day or two. "It's on the cards," he says. "If we get warmer summers, this can happen more easily." Warhurst warns family doctors near major airports to be on alert for cases. Andy Coghlan •

WE HEAR THAT.. You can now wearyour cremated relatives or pets as an attractive piece of jewellery. A company in Chicago is offering to make synthetic diamonds from the ashes of the deceased, which you can then have mounted in the jewellery of your choice. GregHerroof LifeGem Memorials says he can produce goodquality gems, albeit small ones, from pets or people's ashes, usinga process he spent three years perfecting. His technique, based on an industrial diamond-manufacturing process, begins in the cremation oven, where oxygen levels are reduced to prevent the loved one's carbon atoms escapingas C0r The ashes are then heated to 3000 °C in a vacuum, which converts them into graphite. Finally, a thimble-full of graphite is heated under intense pressure for 16 weeks to create the diamond. So even if diamonds are not a girl's best friend, her late best friend can be a diamond. As long as money's no object, that is: a one-carat LifeGem diamond costs a cool $22,000. Herro expects his biggest market to be Japan: some 98 per cent of Japanese opt for cremation, compared with only 26 per cent of Americans.

www.newscientist.com

A cud above the rest

Cows like their clover with a side salad PRESENTATION is vital when it comes to cuisine - even if the diners are cows. Growing grass and clover in separate parts of a field has been shown to greatly increase milk yields, because the animals can eat what they want more easily. Clover is easy to digest and high in protein and sugars, so it is often used to boost milk yields. But although cows usually prefer clover, they get sick if that's all they have to graze on, and like to eat small amounts of grass too. So farmers often graze cows in fields of grass and clover mixed together. Now behavioural scientist Danielle Marotti and her colleagues at the University of Melbourne have found that when cows were grazed in a field where the grass and clover were grown separately instead of intermingled, milk yields were 11 per cent higher after just four days. Separating the grass and clover means the cows don't have to waste valuable eating time searching for the next patch of clover, Marotti thinks. "To pick up those changes in milk yield in such a short time is quite significant," says Dawn Dalley of the Department of Natural Resources and the Environment in Ellinbank near Melbourne. For most farmers, the increase in production could be even greater. That's because the intermingled field in the trial

was particularly rich in clover. The mixed pastures on most farms contain less clover and more closely resemble the grass-only fields in the trial, Marotti says. And she found that the milk yields from fields where grass and clover were kept separate were almost 30 per cent greater than those from fields of grass alone. More work is needed to confirm the results, as the study was small and short, involving just four groups of three Friesian cows. Each group was grazed on different pastures for six days. But it would be very simple for farmers to put the method to the test for themselves. Clover doesn't grow well in the winter, Marotti adds, but farmers could provide separated pastures in the spring, when most cows are producing lots of milk. Rachel Nowak, Melbourne •

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31August2002|NewScientist|9

Special report Mid-air emergencies Airlines are failingto carry basic equipment that could save the lives of passengers who fall ill

Death in the skies MICK HAMER

WHEN Bashkirian Airlines flight 2927 smashed into a cargo plane above southern Germany in July, the deaths of the two aircraft's 71 passengers and crew made headlines around the world. It was the nightmare every air passenger fears. But there is a less visible and largely unpublicised danger. Heart attacks, breathing difficulties, deep-vein thrombosis (DVT) and other medical conditions in mid-air cause as many deaths as plane crashes (see "In-flight emergencies"). Yet a New Scientist investigation has revealed that many airlines are failing to take simple steps that would save many of these lives. This could be done by fitting planes with medical equipment costing just a few thousand pounds. To give passengers in trouble a fighting chance, doctors want medical kits to be standardised so each contains basic equipment such as defibrillators, electrocardiographs and pulse oximeters, which monitor the amount of oxygen in the blood. "When you think of all the money the industry spends on the safety of its planes, better medical equipment would be a very small outlay," says Farrol Khan, of the Aviation Health Institute, a charity based in Oxford that promotes the well-being of passengers. Flying can be very stressful. Passengers have to cope with heavy luggage, crowded terminals and busy check-ins, as well as the physiological changes brought on by altitude. Although aircraft are pressurised, the air pressure inside is usually lower than normal: typically the equivalent of an altitude of between 2000 and 2400 metres. "All these are known cardiac risk factors," says Peter Leman, an accident and emergency consultant at St Thomas' Hospital in London. 101 NewScientist 131 August 2002

One American study found that the risk of dying on a plane was 20 times the risk of dying on the ground. And if you collapse on an aeroplane, the quality of treatment you will receive remains something of a lottery. The captain will ask if there is a doctor on the plane. The odds are roughly 50:50, but even if you are lucky, the doctor may lack relevant expertise. A specialist in dermatology may end up having to deal with their first heart attack since medical school. Your quality of care also depends heavily on what medical equipment the plane is carrying. There is no international standard: for US airlines,

When you're flying at 30,000 feet, it's a long way to the nearest hospital

standards are laid down by the Federal Aviation Administration (FAA); in Europe they are governed by the Joint Aviation Authorities, of which Britain's Civil Aviation Authority is a member. "I think the most important issue is the lack of harmonisation, says William Toff, a cardiologist at the University of Leicester with a special interest in aviation medicine. The concentrations and formulations of drugs in the kits is one problem. They are often poorly labelled and there is little or no guidance for doctors. "If you are under stress it is easy to make dosage errors," Toff says. In general, the minimum standard of equipment in America and Europe is

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There is no international standard for the medical equipment that should be carried on board an aircraft

higher than in many other countries. But one standard item in every airline's kit, the stethoscope, doesn't work on a plane because of the background noise. "It is virtually useless," says Graham Cresswell, chief medical officer of the airline BMI British Midland. Although DVT is the most widely publicised medical problem associated with flying, heart attacks and chest pains are the two most common reasons for diverting a plane. The FAA requires all American aircraft on international flights to carry automatic emergency defibrillators to treat any passenger whose heart has stopped. But they will not be required on short internal flights, such as New York to Washington, until April 2004. In Europe they are not required at all, although most of the major long-haul carriers do have them. Lufthansa and British Airways have some of the best kits around, and BA planes started carrying defibrillators three years ago. Since then, they have been used on five passengers, says Nigel Dowdall, the company's consultant occupational physician. Wherever a heart attack occurs it is often fatal, yet all five passengers left the aircraft alive, CRISIS IN MID-AIR Most frequent medical emergencies (%)

Fainting Gastrointestinal Cardiac Respiratory Neurological

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10

15

20

25

Most frequent medical reasons for diverting a plane (%)

Cardiac Neurological Respiratory Gastrointestinal Cardiopulmonary arrest

10

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20

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i»0

although three later died in hospital. On short-haul flights, most other airlines' planes in Europe do not normally carry defibrillators - and there is no immediate prospect of airlines introducing them voluntarily. That's not good enough for Leman. "If you have a heart attack at 10,000 feet, by the time you have diverted, it will be a good half an hour before you get help," he says. "You won't survive that long." Europe's aviation authorities are reviewing the contents of medical kits, but Britain's CAA says that making defibrillators compulsory is not part of that review. However, as Toff points out, planes have to carry a set of life jackets for the passengers in case they ditch in the sea. "They are rarely used, but no one would argue against their provision on grounds of cost," he says. "Defibrillators are likely to save more lives." All cabin crew on planes are trained to deal with emergencies, even in the absence of a doctor. To provide a more consistent treatment, 40 of the world's leading airlines subscribe to the MedLink service provided by MedAire, a company based in Phoenix, Arizona. MedAire has a team of doctors stationed in the emergency department of the Good Samaritan Regional Medical Center, Arizona's largest hospital, that cabin crew can contact for advice. The team deals with nearly 12,000 mid-air emergencies a year, helping to treat patients and advising pilots on when to divert a plane. But the system relies on information the doctors in Phoenix get from the plane. Without the appropriate kit, describing and monitoring the problem can be all but impossible. A pulse oximeter, which slips on a finger and measures the oxygen saturation of the blood, and an electrocardiograph to monitor the heart should be essential parts of any kit, Leman says. A pulse oximeter, for example, costs less than £400. But according to Dowdall, carrying more monitoring devices won't necessarily improve patient care. Only about half the suspected heart attacks on BA planes turn out to be real, and the airline's philosophy is to divert the plane whenever there is any doubt and treat patients on the ground. Simon Brown, leader of Healix International, a company that specialises in repatriating Britons who fall ill abroad, says that without hard data, it is difficult

"The risk of dying on a plane is 20 times the risk of dying on the ground"

to judge the seriousness of an emergency. He tells the story of a man who had chest pains shortly after take-off on a flight from Florida to Frankfurt. A doctor decided it wasn't serious so the plane went on. Towards the end of the flight the man had a heart attack. Fortunately he survived - and lived to sue the airline for failing to turn back. Some airlines are, however, going beyond what the regulations require to improve in-flight medical care. Since May, all BMI British Midland planes flying transatlantic routes out of Manchester carry a monitoring system called Tempus 2000. Virgin Atlantic and a Swiss business jet charter company called Private Air will soon do the same. Tempus 2000 collects data on the patient's vital signs, such as a diagnostic ECG trace, blood pressure, blood oxygen levels and respiration. Combined, these can help to diagnose blood clots in lungs. The system incorporates a video link to MedAire, so that doctors on the ground can see the patient directly. The airline won't say how much the system has cost them. But Cresswell says: "If it saves just one life then no one will give a damn about the cost." •

IN-FLIGHT EMERGENCIES NO ONE knows exactly how many people die in mid-air. The figures are likely to be under-reported, partly because patients are often certified as having died at the hospital to which they are taken, ratherthan on the plane. A paper in the British Medical Journal(w\ 321, p!338) puts the death rate from illness on planes at one death per2.4to7.5 billion passenger kilometres - an annual death toll of somewhere between 170 and 540. British Airways, which carried 35 million passengers in 2000, had 10 deaths in mid-air. Extrapolating this figure to all the world's airlines puts the total number of deaths in the air at around 500 a year. But Farrol Khan of the Aviation Health Institute in Oxford says the real figure could be as high as 1000. By comparison, the number of people who died in crashes

reported to the International Air Transport Association, which represents 278 of the world's commercial airlines, was 658. There is no standard definition of a mid-air medical emergency. The best available information comes from MedAire of Phoenix, Arizona. Accordingtothe calls it received lastyearfrom aircrew dealing with mid-air medical emergencies, the two most common problems were fainting and gastrointestinal problems. Inthird place was cardiac trouble, followed by respiratory and neurological problems, including strokes. But while these cases total less than a third of calls from airlines they accounted for two-thirds of the instances in which MedAire doctors recommended divertingthe plane so the passenger could be treated on the ground.

3lAugust2002|NewScientist|11

Research news and innovation

Justa handful of parasites makes people immune

New lead in hunt for malaria vaccine RACHEL NOWAK AND MICHAEL LE PAGE

A TRIAL in which volunteers were made immune to malaria by injecting them with just a few of the parasites has revealed a new way to create a vaccine. This may be important if the vaccines now being tested don't live up to their promise. The body tackles infectious diseases in two main ways: it produces antibodies that latch onto invaders or infected cells and neutralise them, or T cells that tell other cells to destroy intruders. Most potential malaria vaccines have been designed to stimulate production of antibodies, but it is very difficult to sustain high levels of the different types needed to fight various malaria strains. In the latest study, however, the volunteers gained protection from the disease through T cells alone. "There was no antibody at all. It was almost unbelievable," says Michael Good, director of the Queensland Institute of Medical Research in Brisbane, who led the study. Other groups have been able to produce a T cell-mediated response against the liver stage of the disease (see Graphic). For instance, a DNAbased vaccine that stimulates this response, created by a team led by Adrian Hill of Oxford University, has just begun the second stage of trials in Gambia. But the Australian

study is the first to show that T cells can attack the blood stage of the disease too. "It's really nice evidence that cell-mediated immunity against the blood stage can protect people," Hill says. The cell-mediated response doesn't occur normally, probably because the huge numbers of parasites overwhelm the T cells before they can do their job. Although some people do naturally develop partial immunity to malaria, it is antibody-based. In the Australian trial, three men and two women were injected every five weeks with red blood cells containing the most deadly species of malaria parasite, Plasmodium falcipamm. On each occasion, the volunteers received around 30 parasites, a tiny number compared with the tens of thousands that invade blood cells after bursting out of liver cells. On the first three occasions, the parasites were allowed to multiply for one week before the volunteers received drugs to clear the infection. The fourth time around, drug treatment was delayed for two weeks - long enough for symptoms to have appeared. One volunteer had dropped out, but the other four appeared to be protected from the disease (TheLancet, vol 360, p 610). "In three of the volunteers we could not detect parasites. The

LIFE CYCLE OF THE MALARIA PARASITE The parasite assumes various guises, making it hard to vaccinate against

1l»|NewScientist|31August2002

Millions of people in Africa and elsewhere still die of malaria

fourth person was interesting. His parasites grew, but he didn't get ill," says team member David Pombo of the LDS Hospital in Salt Lake City. None of the volunteers produced antibodies. Instead, they had an up to tenfold increase in the production of T cells. "[Good's team] has found a completely unexpected route by which you may be able to gain immunity," says malaria researcher Louis Schofield of the Walter and Eliza Hall Institute in Melbourne. The challenge now is to identify the parts of the parasite that produce this immunity, he says, to create a vaccine. The complex life cycle of the malaria parasite has long eluded efforts to develop effective vaccines, but there are now some promising candidates, including the Oxford

vaccine created by Hill's team, the "RTS,S" vaccine developed by GlaxoSmithKline and another developed by the Papua New Guinea Institute of Medical Research. The RTS,S vaccine provokes both an antibody and cell-mediated response, so it targets both the sporozoites injected by the mosquito and the liver stage. In preliminary tests in Africa, the RTS.S vaccine protected 71 per cent of people, better than any vaccine so far. But just two months after vaccination, the level of protection fell rapidly. Nonetheless, the team hopes that the vaccine will reduce the severity of the disease even if it can't prevent it, says Joe Cohen of GlaxoSmithKline. A safety trial on children is already under way in Mozambique, and a larger trial is

www.newscientist.com

In this section • Airbags could conquer asteroids, page 16 • Building houses out of sewage, page 18 • The radio that made itself, page 19

SEXUAL SELECTION

In the mane, darker is more desirable FAKE lions have helped unravel the long-standing mystery of the significance of the lion's mane. It turns put that the darker a male's mane, the better he'll be as a mate. The origin of the mane has long puzzled biologists. Some believe the tough, shaggy hair acts as protection in fights with other lions. Yet scrapping lions don't particularly target their opponent's head and shoulders. And other cat species also fight, but don't have manes. "No one really knew what the mane was for," says Peyton West at the University of Minnesota's Lion Research Center. To investigate, West and her colleague Craig Packer planted lifesize dummy lions near males and females in the Serengeti National Park in Tanzania. Male lions were less intimidated by dummies with lighter, less shaggy manes. Females preferred the opposite, suggesting

Dark, shaggy lions are hot stuff

that they saw males with darker manes as better prospective mates (Science, vol 297, p 1339). The pair also found that males with dark manes have more testosterone and are better able to defend their families. One-year-old cubs are more likely to survive until they are two if they are born to

MEMORY

Sperm remember which way they swam due to begin in October. And in tests on 120 children, the Papua New Guinea vaccine reduced parasite numbers by 60 per cent on average. The team is now trying to improve it further. An effective vaccine may have to combine many approaches. The ideal vaccine would target the parasite at every stage of its cycle, producing high levels of antibodies to prevent the sporozoites reaching the liver in the first place, a cell-mediated response against the liver stage and, now, both against the blood stage. Antibodies against the sexual form of the parasite could also prevent it being picked up by mosquitoes that bite infected people, while those against a malarial toxin recently identified by Schofield could help reduce the severity of symptoms. • www.newscientist.com

THEY turn out to be smarter than anyone thought: sperm can remember the twists and turns they've made. If human sperm turn in one direction, they'll turn in the opposite direction at the next opportunity, Peter Brugger, a neurobiologistat University Hospital, Zurich, has found. "It's certainly not cognitive memory," he says. But they must have some kind of memory.

This kind of behaviour, known as spontaneous alternation behaviour, is found in a wide range of creatures. To see whether human sperm cells exhibit it, Brugger recorded which way 7li» healthy sperm cells turned when confronted with a left or right choice in a T-shaped channel. As expected, half the sperm went left and half went right. But in a maze that forced the sperm to

THE SPERM MAZE Human spermatozoa seem to have some basic form of memory

50%

50%

58%

42%

After a forced right turn, more sperm turn left

darker-maned males. But a darker mane comes at a cost - it makes lions hotter. West says it is likely that only the toughest can put up with this burden. "It's a very exciting contribution to the study of sexual selection," says zoologist Tim Birkhead at the University of Sheffield. James Randerson •

turn right before they reached the T-junction, 58 per cent turned left (see below). Brugger, whose work will appear in Behavioural Brain Research, thinks the percentage that "remember" which way to turn would be even greater if the maze were smaller. The sperm had to swim 10 times their body length after the forced turn, so some of them may already be "forgetting". One simple explanation could be that each turn causes an asymmetry in the mechanism that controls a cell's tail, or flagellum. It then compensates by turning in the opposite direction next time. But it is also possible that the sperm are somehow communicating. "They could be flocking," Brugger says. To test this, he plans to repeat the experiment one sperm at a time. In the body, sperm follow a chemical trail to the egg. "But they may have choices [of which way to turn] when they get very close to the egg," says reproductive biologist Harry Moore of the University of Sheffield. Testing for alternation behaviour could be a way to check the health of sperm used for IVF, he adds. Duncan Graham-Rowe •

31August2002|NewScientist|T5

PATENTS Red means dead Wouldn't it be great to see at a glance whether a fuse in a plug has blown without needing to test it? Ferraz Shawmut, a company in Massachusetts, has the answer (WO 02/45110). Its fuse consists of a ceramic tube, inside which is a wire strip of low resistance that's designed to melt when current flow exceeds a specified limit. That much is standard. But the outside is painted with a red dye, on top of which is an aluminium coating. This has a thin spot, of high electrical resistance. Normally, a current takes the path of least resistance, through the wire strip. But if a current surge blows the strip, the current briefly diverts to the outer aluminium coating, vaporisingthe thin spot and exposingthe telltale red dye.

Light conversation

If a comet needs deflecting, keep it in one piece

PLANETARY DEFENCE

Cosmic pillow fight could fend off space invaders HAZEL MUIR

AIRBAGS save lives on the road, but one day they could also save the planet. At least, that's the view of one mathematician, who is suggesting that they could be used to nudge asteroids or comets that are on a collision course with the Earth gently out of harm's way. All sorts of ideas for deflecting objects heading for Earth have been touted since the comet ShoemakerLevy 9 smashed into Jupiter in July 1994. These include detonating a nuclear bomb on their surface. But this might not work: some asteroids are more like a pile of rubble than a solid, and so would absorb the energy from a nuclear blast. Computer simulations by Erik Asphaug of the University of

16|NewScientist|31August2002

California at Santa Cruz suggest that a rubbly asteroid would absorb so much energy from a nuclear blast that the explosion would have little effect on the course of one of these "cosmic beanbags". A blast would also risk splitting an asteroid or comet into dangerous fragments that would still head for Earth. It would be far better, says Hermann Burchard of Oklahoma State University in Stillwater, to send spacecraft to fly alongside the threatening object and inflate a giant bag some kilometres wide, using gas produced by a chemical reaction. The spacecraft would then push the bag against the asteroid. This billowingspace pillow, Burchard argues, would distribute pressure evenly over a large enough area to deflect the asteroid or comet

gently, but still keep it intact. Burchard thinks this should work for asteroids or comets up to 10 kilometres wide, providing the spacecraft carried enough fuel. "It seems a safe, simple and realistic idea," he says. He admits, though, that many questions have to be answered, such as what kind of airbag material - Mylar, perhaps would be tough enough for the job. However, Asphaug thinks there's a simpler solution. "You probably can't reliably use a nuclear explosion with predictable consequences," he agrees. But he thinks that simply attaching a rocket motor-perhaps with some kind of electric or even steam propulsion - to an asteroid or comet would do the trick, without breaking it into fragments. "Asteroids and comets are not so fragile that you can't touch them they get cratered all the time and don't fall apart," adds Asphaug. "So you just need to apply gradual thrust over time. This can be done more simply without bags of Mylar getting in your way." *

The University of Warwick has a solution to fears that a cellphone's hands-free set may focus microwave energy on the brain, because the earphone lead acts as an antenna (WO 02/054610). Its answer is to convert electrical signals from the cellphone into optical pulses. These are fed alongaplastictu be that acts as a light guide, taking the signal up to the earpiece, where another converterturns the light back to electricity. The tube cannot act as an antenna, so no radio energy is channelled to the earpiece. Warwickalso uses a crystal-based earpiece speaker, instead of an electromagnetic coil, to minimise the action of a ny stray electric fields.

Key position Land Rover wants to foil the high-tech tricks used by carthieves(GB 2332548). These days, many car door locks rely on keys that transmitand receive coded signals. But thieves can steal these codes by using an electronic device to interrogate the keys of unsuspecting passers-by. Land Rover hopes to foil them by letting the car's owner choose a unique position from which he or she always unlocks the car. It does this by putting antennas in the wing mirrors and brake lights that let the car triangulate the position of the key that is trying to unlock the car. Only the rightful owner knowsjust where to stand to do this. So a thief will be transmitting the right codes, but from the wrong place. Unless they saw them parking, that is. Barry Fox

www.newsdentist.com

AMIMAL PHYSIOLOGY

The Sun warmed up evolution for us all JEFF HECHT

A SMALL Australian marsupial is giving new clues to how the first mammals may have regulated their body temperature. The fat-tailed antechinus, or Pseudantechinusmacdonnellensis, basks in the morning sun to raise its body temperature after waking up from a nightly period of torpor. It's the first direct evidence of a mammal u sing basking to increase its body temperature. And because it belongs to a group that can be traced back to some of the earliest mammals, its behaviour could provide insight into how they originally became warm-blooded. MAMMALS WARMING UP Body temperature of the antechinus ("() «h

21

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03 06 09 Time of day

12

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The first mammals were about the size of a shrew and, because of their small size, were likely to lose body heat quickly. Their metabolic rates were probably slower than modern mammals, so how did they maintain their body temperature? Fritz Geiser of the University of New England in Armidale, New South Wales, thinks he's found an explanation (Naturwissenschaften, DOI: 10.1007/500114-002-0349-4). His team found that antechinus adults were active with body temperatures of between 33 and 37 °C until about midnight, when they cooled to between 16 and 27 °C and dropped into torpor. On clear days, they emerged from their dens at about 9.40 am and basked in the morning sun. The basking helped them to warm up at 0.28 °C per minute, more than twice as fast as when they were out of the sun. As with the antechinus, Geiser thinks early mammals may have combined periods of torpor, which save energy, with sessions of basking to warm up again quickly. This behaviour may have been one of the first steps towards developing a fully warm-blooded metabolism, Geiser thinks. Basking probably provided an important advantage for ancestral mammals, Geiser adds. He

calculates that a mammal the size of the antechinus would have needed a good five hours to warm to body temperature if it had to rely solely on its internal metabolism, so warming up by basking would have given the animal more time to be active during the day at a lower energy cost. Many small mammals such

Sitting in the morning sun gets an antechinus started

INSECT BEHAVIOUR

Down on the farm the bees are in charge THE world's first farmer bees have been discovered in the Amazon basin. The Schwarzula bees keep a "herd" of aphid-like bugs from which they collect wax to repair their nests and a sugary substance to make honey. Reports a century ago suggested that some species of bees have taken to animal husbandry, but the evidence was sketchy. The Amazonian discovery marks the first time that bees have been observed domesticating another species.

www.newscientist.com

The bees and their herd, a type of soft-scale insect, are so new to science that they have not yet been given species names. The bees are only i» millimetres long, but their soft-scale insect livestock are about twice that size. Uniquely, the two sets of insects live together in cavities made by a single species of wood-chomping caterpillar in the trunks of a particular tree. "The soft-scale insects have not been found anywhere else," says social

as ground squirrels and bats go torpid when they are inactive, but researchers had thought the trait developed independently. Geiser now thinks it may be an ancestral trait that larger mammals ditched because they dissipate heat more slowly. "If you're very big you don't have to bother," Geiser told New Scientist. •

insect specialist Francis Ratnieks from the University of Sheffield. The main thing the bees appear to be getting from their herd is wax, Joao Camargofrom the University of Sao Paulo in Brazil will report in a future issue of Biotropka. The bees collect the soft-scale insects' waxy coating, which accumulates on their backs, and use it to reinforce and repair their nest. Making the wax themselves would cost them more energy, says Ratnieks.

The soft-scale insects feed on the tree's sap, and in the process produce a sugary substance called honeydew which the bees then collect to make honey. This arrangement is similar to that in many ant species which farm sap-sucking aphids. Whenever the bees need to build a new nest elsewhere, it seems they transport the wingless insects with them. "Even in young nests, we observed many soft-scale insects," says Camargo. But because the fully grown insects are so much larger than the bees, it's probably only the newly hatched larvae that hitch a ride when the bees move. James Randerson *

31August2002|NewScientist|l7

SEWAGE RECYCLING

The house that cack built COUNTRIES running short of landfill space could soon be using sewage to build homes for their citizens instead of dumping it. A team in Taiwan has found that sludge from sewage works can be used to bulk up ordinary house bricks. "It's a win-win situation because it converts the wastes into useful materials and alleviates disposal problems," says Chin-Huang Weng, leader of the team at l-Shou University in Kaohsiung County that devised the process. The impetus behind the idea was to find new uses for the 670,000 tonnes of sewage sludge the island produces each year, and for which landfill space is fast running out. Although the solids Weng and his team added to the bricks were filtered from industrial effluent, he says domestic sewage would do just as well. In a paper accepted for publication in

Advances in Environmental Research, Weng's team report achieving their best results when sewage sludge accounted for 10 per cent of the material in clay bricks fired at about 900 "C. But the process worked even when the "biobricks" contained as much as 30 per cent sludge. As well as getting rid of the sludge, there are other benefits. The firing process locks away for good any toxic heavy metals in the sludge, and also destroys any hazardous microbes and organic material. And the bricks don't smell at all, says Weng. But Weng admits that people might need a little convincing to live in such intimate contact with their own waste. "Legal approval and public acceptance" remain to be sought, he says. While agreeing that such a use of the

V

Bricks can be made with up to 30 per cent sewage sludge sludge benefits the environment, John Hobson, an expert in effluent treatment at Britain's Water Research Centre in Medmenham, Buckinghamshire, says that brick makers might need to be assured that there is nothing about the process

that would alter the colour or durability of bricks that might put potential customers off. He also says such bricks might need to meet additional standards to guarantee they don't pose new health hazards. AndyCoghlan •

M

In next week's issue I• Shifting shadows

Nature's constants are changing, but no one knows why. John Barrow thinks the answer I could lie beyond the fourth dimension

I Troubled waters Can oil companies and wildlife share one of Europe's last great wetlands?

|Face-off Souped-upCCTV could help us spot a terrorist before they get on the plane. But only if the | face-recognition software is up to the job

Gladerunners Forget the dense, foreboding thicket beloved of the brothers Grimm. Europe's primeval landscape was more like elegant parkland, and all thanks to some unlikely groundskeepers

PLUS Rajendra Singh, India's river-maker, I has had astonishing success in restoring water to drought-prone landscapes. But it has almost cost him his life

"Stunning." ID "Breathtaking." | "Revolutionary." SELF-ORGANISING SYSTEMS

Radio emerges from the electronic soup DUNCAN GRAHAM-ROWE

IF ONLY it had been this easy for Marconi. A self-organising electronic circuit has stunned engineers by turning itself into a radio receiver. This accidental reinvention of the radio followed an experiment to see if an automated design process, that uses an evolutionary computer program, could be used to "breed" an electronic circuit called an oscillator. An oscillator produces a repetitive electronic signal, usually in the form of a sine wave. Paul Layzell and Jon Bird at the University of Sussex in Brighton applied the program to a simple arrangement of transistors and found that an oscillating output did indeed evolve. But when they looked more closely they found that, despite producing an oscillating signal, the circuit itself was not actually an oscillator. Instead, it was behaving more like a radio receiver, picking up a signal from a nearby computer and delivering it as an output. In essence, the evolving circuit had cheated, relaying oscillations generated elsewhere, rather than generating its own. Layzell and Bird were using the software to control the connections between 10 transistors plugged into a circuit board that was fitted with programmable switches. The switches made it possible to connect the transistors differently. Treating each switch as analogous to a gene allowed new circuits to evolve (see Diagram). Those that oscillated best were allowed to survive to a next generation. These "fittest" candidates were then mated by mixing their genes together, or mutated by making random changes to them. After several thousand

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EVOLUTION OF A CIRCUIT What should have been an oscillator became a radio

Connect transistors using softwarecontrolled switches Switches adopt a random initial connection pattern

Software tries to evolve an oscillator circuit by mutating and mating the best connection patterns

Circuit switched on and output measured

Is output a smooth high-frequency oscillating signal

One pattern picks up radio signal which software recognises as an oscillation, even [hough transistors have not produced it

generations you end up with a clear winner, says Layzell. But precisely why the winner was a radio still mystifies them. To pick up a radio signal you need other elements such as an antenna. After exhaustive testing they found that a long track in the circuit board had functioned as the antenna. But how the circuit "figured out" that this would work is not known. "There's probably one sudden key mutation that enabled radio frequencies to be picked up," says Bird. •

"Unquestionably a ground-breaking work whose audacious arguments can only be described as stunning and revolutionary in intent and scope." - Roman Franco, PhD

Is this a "time of uncertainty"? Or can we understand exactly what is going on with the markets, the economy, politics and social trends? The answers can be found in the new science of socionomics. Learn how history unfolds not as cycles but as form-driven fractal "waves." Join countless luminaries who have found The Wave Principle of Human Social Behavior to be an intellectual thrill. "The book is beautiful. Congratulations for assembling this stimulating and controversial (from the point of view of mainstream research) book." - Didier Sornette, PhD; Professor, Institute of Geographic and Planetary Physics, UCLA "The insights in this book originate with the careful inductive analysis published in the 1930s by Ralph N. Elliott and culminate with the important and breathtaking work that Robert R. Prechter, Jr. has pursued over the last three decades." - Hernan Cortes Douglas, Professor of Economics; Luksic Scholar, Harvard University "Socionomics establishes a research agenda that places it at the developmental forefront of the newest research methodologies involving patterns, systems, interactive non-linear influences and the pluralism of the sciences. The insights and issues developed by this rich and robust research agenda provide a plethora of fruitful directions for investigation into the nature of social processes." - Michael K. Green, PhD; Professor of Philosophy, SUNY I just finished the book - amazing. Truly a masterwork." -ArthurA. Merrill, MBA Harvard; President, Merrill Analysis, Inc.

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31 August 20021 NewScientist 119

PLANETARY SCIENCE

Ancient time capsule reveals Martian past NICOLA JONES

A GLIMPSE of what Mars was like 4 billion years ago has added fuel to the fiery debate about whether the Red Planet once hosted life. By extracting gases from inside the famous Martian meteorite ALH84OO1, researchers have revealed tantalisingly mixed news for people who believe the meteorite contains alien fossils. The new work suggests Mars once had a magnetic field about as strong as the Earth's. It also had a much thicker atmosphere then, but has been in a deep freeze ever since. "The conclusions are supportive of our hypothesis, and certainly wouldn't harm it," says David McKay from NASA's Johnson Space Center, who first proposed that the meteorite contains signs of ancient magnetically orienting bacteria. Benjamin Weiss, the geologist from the California Institute of Technology who led the research,

agrees the magnetic field findings add weight to the fossil theory, but the chilly climate he has deduced for Mars is "not very encouraging from the life perspective". At 4.5 billion years old, ALH84OO1 is the oldest bit of rock yet found on any planet. Most researchers agree that evidence within the meteorite suggests it was kicked off Mars 15 million years ago when some other body crashed into the planet, and that it landed on Earth 11,000 years ago (see Graphic). It also appears that an earlier impact heated the rock 4 billion years ago, while it was still on Mars. If it has remained cold enough since then, then any magnetic alignment or gas in the rock today was literally set in stone when it cooled 4 billion years ago. But no one could be sure that the rock hadn't been heated up again in the intervening period. To find out, Weiss looked at the amount of argon-4O in the meteorite. This gas is produced at a

steady pace by the decay of radioactive potassium-4O, but rock spits it out when heated. Weiss determined that only 5 per cent of the expected amount of argon has been lost over the past 4 billion years, from which he calculated that the rock must have been no hotter than 500 °C all that time, probably much colder. He speculates that it has probably stayed deep-frozen in conditions similar to Mars's current -90 °C to -40 °C (Earth and Planetary Science Letters, vol 201, p 465). The magnetic record in the rock is revealed by the alignment of an iron ore called magnetite. If Weiss is right, the rock has spent the past 4 billion years well below the temperatures at which magnetite realigns, meaning its magnetic record must date from 4 billion years ago too. Weiss determined that the strength of that ancient field was about the same as the Earth's today (Earth and Planetary Science Letters, vol 201, p 449). Mars doesn't have a planetary field any more, but Weiss's work supports the theory that it once did.

That's good news for those who believe these magnetite traces are part of the fossils of bacteria similar to bugs found here on Earth that orient to magnetic fields. "A precondition for there being fossils is that there was a field," says Weiss. The low temperature also makes it unlikely that the magnetite grains are simply the remains of minerals that have been heated to extreme temperatures - the only other explanation for the traces (New Scientist, 19 May 2001, p 38). But Weiss adds that it is possible the magnetite was produced by heating earlier than 4 billion years ago. He says the results also help explain some puzzling results about other gases trapped inside ALH84OO1, which are very different from the atmospheric gases on Mars today: it's simply because they're 4 billion years old, he explains. Since then, Mars must have lost a lot of its atmosphere. The earlier, thicker atmosphere, along with a magnetic field to protect against cosmic rays, could have made Mars a reasonably comfortable place for life. •

LIFE OF A MARTIAN METEORITE

Lost on the plains of Mars? A compass won't help you

20 I NewScientist 131 August 2002

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[Chemistry

Chemists say we can all lookforward to a cleaner, greener and tastierfuture. Eugenie Samuel is ready to raise her glass

Green light for ion age THE promise of more environmentally friendly chemicals plants has come closer, now that five major manufacturers have unveiled plans to scale up production of a new kind of solvent. Since 1995, "green" chemists have championed ionic liquids (ILs) as possible replacements for the toxic organic solvents that are used for key reactions in a range of industries from paper making to Pharmaceuticals (New Scientist, 5 September 1998, p 13). But their campaign has been in vain, until now. "This is a huge enabling step," says Kenneth Seddon, who studies ILs at Queen's University, Belfast. Ionic liquids consist of simple salts similar to sodium chloride, except that one of the ions is a big unwieldy molecule that doesn't stack easily in the solid state. This means that, just like organic solvents, ILs are liquid at room temperature, and are capable of dissolving many of the reagents used in industry. But they are far less volatile than organic solvents, so they don't emit dangerous fumes, and they're

22|NewScientist|31August2002

not as flammable. It might also be easier to extract impurities from ILs, so plants could recycle them instead of producing a constant stream of chemical waste. But despite the environmental benefits, manufacturers were not willing to scale up production of ILs. Their change of heart is due to recent discoveries showing that ILs could also be more effective than current solvents. At the meeting, Robin Rogers's research group at the University of Alabama inTuscaloosa presented its findings on an IL called "bmim chloride", also known as an imidazolium salt. In 2000, Rogers's colleague Rick Swatloski was filtering bmim chloride when he noticed holes in the filter paper. In further tests he found that bmim chloride dissolves not just paper but also cellulose from wood, which is normally considered fairly insoluble. So as well as replacing organic solvents in paper making and other cellulose industries, bmim chloride could remove the need to pretreat

"Several dozen solutions now on the market will soon be custom-made by the tonne"

cellulose to help it dissolve. This would be a boon for the paper-making industry, which the US Environmental Protection Agency criticised in June for producing too much toxic waste. Another promising find came from Gary Baker of Los Alamos National Laboratory in New Mexico. He reports that monellin, a berry protein, remains intact in some ionic liquids even when heated up to 99 °C. That's at least twice the temperature that could be reached with an organic solvent. Drugs manufacturers are excited about this because higher temperatures mean higher yields. Several dozen ILs that are now on the market in small quantities will probably soon be custom-made for industry by the tonne, representatives from Merck and Solvent Innovation in Germany, Sachem USA, Ozark Fluorine in the US and Cytec Canada told the meeting. However, the environmental benefits can't be taken for granted. Baker's finding that proteins are so stable in ILs hints that the chemicals could be less toxic than organic solvents. But he and other chemists at the meeting stress that it would be irresponsible to market any chemical as "green" without proper environmental assessments. As yet neither these nor basic toxicity studies have been done on any ILs. •

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American Chemical Society National Meeting in Boston, Massachusetts, 18 to 22 August. Coverage of other scientific meetings is at www.newscientist.com/conferences

Shape is everything for a good glass of wine IT'S time to stop serving wine in tumblers and get a decent set of glasses, because the shape of a glass really does make a difference to the way wine tastes. Wine connoisseurs have always claimed that the shape of the glass matters because it affects how close your nose gets to the wine and also how easily volatile aromatic compounds can escape. But Kari Russell of the University of Tennessee in Knoxville wondered if the shape of the glass affects the wine's chemistry as well. Russell measured the concentration of phenolic compounds in a Merlot as it sat in three different glasses: a flute glass, a Martini glass and a wide Bordeaux glass. Phenols are ring-shaped compounds containing hydroxyl groups, and as antioxidants are thought to be responsible for some of the health benefits of moderate red wine consumption. After pouring the wine, Russell found that the concentration of a phenolic compound called gallic acid increased, presumably because the action of pouring triggered reactions that converted gallic tannins in the wine into gallic acid. But between 10 and 20 minutes later, the concentration of gallic acid in the flute and Martini glasses remained high, while

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the concentration in the Bordeaux glass fell. Russell thinks this is because a higher surface area of the wine is exposed to air in a Bordeaux glass. Oxygen drives the formation of compounds called catechingallate esters from the gallic acid. When esters pass your lips, they precipitate the proteins in your saliva, making the wine taste dry. Although Russell saw a similar chemical development for other phenolic compounds, the shape of the glass didn't make such a difference. After decanting wine into an inelegant lab beaker to prevent psychological bias, she asked a panel, mostly of students, to taste wine that had sat in different glasses. The majority didn't notice any difference. But one panellist - an older professordid seem to be able to tell. "I think with training the glass might make a difference," says Russell. •

Toxin detector can find one molecule at a time A CHEMICAL sensor has been developed that is so sensitive it can detect just one molecule of an environmental toxin or warfare agent. The detector is modelled on the tiny openings that let ions in and out of the cells in our body. These openings, called ion channels, span the walls of human cells. A thin protein flap guards each opening, and in nerve cells the flap can be

It looks as though the wine connoisseurs were right all along

controlled by neurotransmitters. When a neurotransmitter binds to a site in the channel it pushes open the flap, letting ions flow intooroutofthe cell. Hagan Bayley of Texas A&M University in College Station wondered if a chemical sensor could be based on a similar principle. Many of the nerve agents used in chemical warfare, such as sarin, block these channels, which is why they are so toxic. Bayley started with an existing experimental set-up in which solutions of ions are separated by a barrier containing a single protein pore. Electrodes on each side of the barrier measure the current that flows when ions move through the pore. But certain nerve agents stop the pore working by permanently opening it. So a chemical sensor based on this idea would be useless as soon as it came into contact with a toxin. That means it would be impossible toknowthe identity or the concentration of the offending compound. Bayley's answer is to genetically engineer a modified version of the protein pore, so that the binding site for the particular toxin he's interested in doesn't fit quite as well as normal. For example, he made a binding site containing some but not all of the chemical bonds necessary for it to bind to a toxic arsenic compound. Molecules of the compound that made their way into the site could bind only transiently, so the pore opened but snapped shut again a fraction of a second later. The frequency at which this happens indicates how concentrated the neurotoxin is. The more molecules around, the more often one finds its way in to block the pore. Even better, says Bayley, the site can be designed so that a variety of chemicals bind to it more or less tightly. They sit there for different lengths of time before popping out, and can even push the flap open by varying amounts, allowing more or fewer ions through. The length of the current pulse and the rate at which it flows provide a kind of electrical signature that can be used to identify the compound, he says. Bayley's ability to detect and identify single molecules is unique, says Tim Swager of the Massachusetts Institute of Technology in Cambridge, who also works on developing ultrasensitive chemical sensors. But a device based on this technology will have to be extremely selective, to avoid false alarms. • 31August2002|NewScientist|23

In brief have vaporised tens or even hundreds of metres of the upper ocean, wiping out surface marine life as well as anything on land, says Gary Byerly of Louisiana State University in Baton Rouge. Although no crater has been located, Byerly and Don Lowe from Stanford University in California found debris from the blast in rock deposits in Australia and South Africa (Science, vol 297, p 132).

Trails of destruction

Trylickingthisfor the ultimate tingle... LOVERS of spicy food who are seeking new kicks will appreciate the work of Christophe Galopin of Givaudan Flavour Research in Cincinnati, Ohio. Galopin has isolated the chemical group responsible for the tingling

Autism link crumbling GUT disease does not make children more likely to develop autism. The new finding undermines a crucial link in the argument that the combined measles, mumps and rubella vaccine can cause autism. Critics of the MMR vaccine argue that it aggravates chronic gut disease, which subsequently triggers autism. But by analysing data from British GPs, Corri Black's team at Boston University has shown that children who developed autism were no more likely than others to have had gut disorders (British Medical Journal, vol 325, 24|NewScientistl31August2002

effect of Szechuan pepper, whii like tiny bubbles popping on the tongue. It's caused by a compound called sanshool, which also tastes pungent, so Galopin synthcsised a range of compounds similar to sanshool and got an expert taster to rate them. The simplest compound that just created the tingle contained two carbon double bonds separated by two

bonds, with an amine group on one end, he told the American Chemical Society meeting in Boston this week. Nobody knows why this group creates the characteristic sensation, but Galopin says it almost certainly binds to a particular touch receptor. He's developed a powdered compound containing the group that could one day be added to foods.

p 419). The results show that about 9 per cent of vaccinated children suffer gut problems, irrespective of whether they later develop autism.

about 50 days. Tekeshi Kon and Tetsuo Yoshino at the University of the Ryukyus in Okinawa province made the discovery by counting the number of daily growth rings in the teeth of the fish (Ichthyological Research, vol 49, p 224).

Fish in a hurry A TINY fish that lives in coastal waters off Japan has snatched the prize for the youngest breeding age of any vertebrate in the wild. The fish, from the genus Schindleria, is less than 2 centimetres long and can start reproducing at just 23 days old. The previous record holder was the pygmy mouse, which matures at

Deep-sea haven ONLY life shielded in the ocean depths could have survived after a 20 to 5O-kilometre asteroid crashed into the sea 3.47 billion years ago. Researchers think life began as single-celled marine organisms before the impact. The blast would

CLUMSY children don't just have problems with their coordination. Their brains also have difficulty processing what they see. Hermundur Sigmundsson at the Norwegian University of Science and Technology in Trondheim and his team tested the visual abilities of 13 children who had performed poorly at coordination tasks. The visual tests involved picking out patterns in a jumbled image and spotting groups of dots travelling in the same direction in a sea of random movement. The clumsy children did worse than a control group in both tests, according to a report to be published in Behavioural Brain Research.

Homemade antimatter PHYSICISTS have finally solved a problem that has baffled many in the field of antimatter research how to type the symbols for antimatter particles. In standard physics notation, antimatter particles are represented by a line over a letter or character. But there's no easy way to do this in a Microsoft Word document, causing no end of headaches for physicists trying to write about antimatter. Now Don Summers and his colleagues from the University of Mississippi in Oxford have designed a new font specifically for the job. Users can add a line over a character simply by keying in shift-5. The font, called LinguistA, can be downloaded from www.phy.olemiss.edu/HEP/ LinguistA.sea.hqx. •

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Comment and analysis

Why we must pay more Cut-price vaccines sound like good news for the world's poor, but not if it means drugs companies lose interest in developing better ones, says Rino Rappuoli BRITAIN'S health experts are bracing themselves for a major outbreak of an entirely preventable disease. Amid fears about the safety of the MMR three-in-one vaccine, parents are requesting shots of individual vaccines and finding the cupboard is bare. Clinics have had no fresh supplies of mumps vaccine for months. In Australia, doctors recently had to stop immunising toddlers against deadly meningococcus C bacteria after they too ran out of vaccine. As for the US, a crisis over smallpox vaccine supplies was only averted when a drugs plant in Pennsylvania uncovered 90 million doses lying forgotten in its freezers. And for much of the past year, vaccines for tetanus, diphtheria and whooping cough were in such short supply in the US that children were having to miss routine booster shots. It gets worse. The vaccines for anthrax and smallpox haven't kept up with the times: neither would meet safety standards if they were being developed today. And although new vaccines are desperately needed to treat diseases such as tuberculosis and malaria, "Big Pharma" has shown little interest in developing them. In short, our entire system for supplying and developing vaccines has become dangerously fragile. What's going wrong? It's true that inventing effective vaccines for AIDS, malaria and a few other diseases is proving tougher than anyone imagined. But scientific obstacles are only part of the wider story. Researchers have known for years how to make better anthrax and smallpox vaccines, yet only now, prompted by the threat of terror attacks, are funds available. A good vaccine is nearly always the most effective way to tackle any infectious disease. Yet there is a dangerous disparity between the power of vaccines and the money we are willing to invest in them. Put simply, vaccines should cost more. Our first thought on hearing about some new experimental immunisation is often "Will it be affordable for the world's poor?". But a www.newscientist.com

vaccine that never makes it to trial is no use to anyone, rich or poor. As a microbiologist working for industry, I recognise that my motives might be open to question. True, the mandate of biotech and pharmaceutical companies is to make money. But they can do that perfectly well without vaccines - and many are. Since 1965, the number of American vaccine producers has dwindled from 37 to 10, and there has been a similar decline in Europe. Over the decades, vaccine researchers like myself make the trek to corporate boardrooms to convince our colleagues to invest in a better shot to fight some dread disease. But time after time, our projects can't compete for profitability with the next Viagra or big ulcer drug. And that's despite a renewed awareness of the importance of vaccines. The millennium began with the launch of the Global Alliance for Vaccines and Immunization, designed to expand access to vaccines and develop new ones. To date GAVI has amassed just over $1 billion dollars towards that goal, roughly three-quarters of it from the Bill and Melinda Gates Foundation. But valuable as such efforts are, the vaccine

"Time after time, our vaccine projects can't com pete for profitability with the next Viagra"

industry cannot be run like a charity forever. The aim must be to make it in companies' interests to invest in vaccines. Yet even institutions and governments with a humanitarian vision are doing little to bring companies to the table, and a lot to drive them away. The US Centers for Disease Control and Prevention (CDC), for example, recently asked Wyeth Lederle Vaccines to slash the price of its pneumococcus shot from $58 to $48 dollars a dose. Vaccine advocates of all stripes often push for low prices in an effort to make them as widely available as possible. As noble as their intentions are, Tm convinced they are leading us to a vaccine crisis. Consumers already massively undervalue disease prevention. Parents of a sick child who have the money will gladly spend $10,000 on a drug regime, yet many balk at spending a fraction of this on a couple of doses of a vaccine that would prevent the illness. Policy makers complain about the few hundred dollars it costs to give babies the standard package of shots. But how much is lifelong protection against diphtheria, whooping cough, tetanus, poliomyelitis, smallpox, measles, mumps, rubella and Haemophilus influenzas actually worth? The answer is a lot more. Henry Miller and Stanley Falkow at Stanford University and I have suggested a few steps governments could take (Science, vol 297, p 939). Instead of asking for that $10 per dose discount from Wyeth Lederle, for instance, the CDC might have negotiated with the company to reinvest the money into more vaccine programmes. Governments should give tax credits to support vaccine research, extend patents on vaccines and streamline regulations to allow vaccines to be more easily exported. In the end, rich countries and their citizens will need to shoulder much of the burden of inventing and manufacturing vaccines for poor countries and poor people. But developing countries, too, need to assign a higher priority, and therefore higher budgets, to vaccines. Developing and distributing vaccines has always been great public policy. To reverse the continuing degradation of vaccine supplies, it will need to be made a good business as well. • Rino Rappuoli is head of vaccine and infectious disease research at Chiron Corporation and co-chair of the GAVI task force on vaccine development

3Uugust2002|NewScientist|25

Letters Tainted aid From Andrew Clegg It is untrue to say that Zimbabwe, or any other country in Southern Africa, has refused food aid that contains genetically modified maize, as you state in your Editorial (3 August, p 3). What they have turned away, as your report on page 4 says, is unmilled GM maize that could be planted. I understand that requests to the donor to mill it have so far been rejected. Zimbabwe is not the only country to have made this request. The unfortunate implication that this is due to a lack of understanding in the region about the implications of GM technology is very far from the truth. Indeed, the GM debate here seems to be conducted at a far higher and less hysterical level than I see it is in Britain. This is not just a Zimbabwean issue, but one that affects the whole of southern Africa. All the countries in the region are being forced to consider their response to the importing of GM food products. All are currently working on issues concerned with biosaf ety and local biodiversity, having endorsed the Cartagena Protocol on Biosafety, and the nub of the problem is a simple one. This part of the world exports food mainly to Europe for the high-quality end of the market. Its beef, in particular, is renowned not only for its excellent taste, but also for the fact that it can all be guaranteed wholly organic. The concern amongst agronomists here is that this market strength will vanish if there is even the slightest suspicion that products can no longer be guaranteed GM-free. As the ActionAid statement pointed out, there is a widely expressed concern here that the refusal to mill GM maize before sending it as food aid may be an attempt to undermine the viability of the region's agricultural sector by bringing its organic and GM-free status into question, thereby opening up the area to the high-tech seed multinationals. I have no means of judging the validity of this argument, but it would not be out of 261 NewScientist 131 August 2002

line with the general experience of the region. On the one hand, government subsidies on maize production have been discontinued under pressure from the World Trade Organization - precipitating, for example, a widespread switch from maize to cotton in Namibia. And on the other, Irish butter is dumped on the market and sells for £1 per kilogram, suppressing the local dairy industry. It now seems that it's OK for the starving here to eat subsidised maize, just as long as it is GM and grown in America. Windhoek, Namibia

People aren't bananas

chimps. 98 per cent of those amino acids are the same. The 50 per cent figure for people and bananas roughly means that half of our genes have counterparts in bananas. For example, both of us have some kind of gene that codes forcellgrowth, though these aren't necessarily made up of the same DNA sequences. Thefigures quoted for human populations are much more specific and are about gene variants. In this study, what is meant is that50per cent of the genes of all the people in Europe, on average, are specific types that have come directlyfrom Middle Eastern populations. So no, the people of Baghdad are not bananas, and neither are we-Ed.

Weightless rocket

From Mark Peplow, Science Media Centre, The Royal Institution Your report about genetic differences between people in different parts of the world was interesting (10 August, p 17). Apparently "modern inhabitants of Paris... share an average of 50 per cent of their genes with people from Baghdad". Compare this with the frequently cited statistic: "Humans share 50 per cent of their genes with a banana." Does this mean that the residents of Baghdad are bananas? London This is a common source of confusion, and no wonder. There are many different ways of comparing genetic similarity. The often quoted fact that people are genetically nearly identical to chimps, for example, comesfrom the analysis of amino acids coded for by just a couple of genes that we share with

From Richard Glover Your article claims that controlling gravity will not help launch spacecraft, because making them lighter will reduce the weight of the propellant (17 August, p 20). This, in turn, will reduce the rocket's thrust. However, the thrust of a rocket depends on the mass ejected in the exhaust, not its weight. Otherwise rockets would become less effective the further they were from a planet. The thrust would only be decreased if the spaceship's weight was lowered by reducing its mass. So perhaps research into antigravity is not so useless after all. Croydon Richard Clover is correct. We failed to distinguish between a system that reduces gravity, and one that reduces mass-Ed.

Lives come first From Glenn Alexander The idea that avoiding radio interference is more important than saving lives is very offensive to me, as I'm sure it is to most people (3 August, p 8). Perhaps the management at the Radio Authority should adopt a more humane rather than bureaucratic approach. Shenyang, Loaning, China

Active ingredient From James Michael Howard You report research that suggests semen may have antidepressant effects, and specifically that it contains hormones that reduce depression (29 June, p 5). In 19851 suggested that depression is due to reduced levels of dehydroepiandrosterone (DHEA), and research since then has supported this. In response to your article, here's a quote from a 1976 paper: "In a group of men with established fertility, dehydroepiandrosterone sulphate had the highest concentration [in semen] and testosterone sulphate had the lowest" (Clinical Endocrinology, vol 5, p 253). I suggest that the antidepressant effects of semen are due to DHEA. Fayetteville, Arkansas

Wisdom in the stars From Jon Stem Brian Davies speculates on what science would be like if astronomy didn't exist (10 August, p 22). In the late 19 8os Douglas Adams asked what a society would be like if no stars were visible from its planet. In Adams's life, The Universe and Everything, the people of Krikkit only discover that they are not alone when an alien spaceship crashes on their planet. After rapidly developing of a space programme, they behold the Universe for the first time and decide that it has to be destroyed. Millennia of isolation have left them believing that they are the centre of the Universe. Finding that this is not the case destroys their sense of identity and prompts them to embark on a xenocidal war lasting 2000 years. Laguna Beach, California From Ross Sargent Your articles states: "Astrophysics and cosmology would have had to wait f or 19 sos technology specifically planes such as the X-15 that could fly at high altitude, above the clouds." I suggest that this more www.newscientist.com

See our website for letters on: • Impact craters in church • Media piracy • Selfish DNA than a little unfair to pioneers of, say, cosmic ray studies. Victor Hess did experiments in a balloon in 1912, and Robert Millikan's 1923 Nobel prizewinning work involved a Condor bomber. Not everything would have had to wait for the X-15. Folkestone, Kent

Chemical sceptics From Gail Wiltse Inyourarticleondopamineand belief in the paranormal (27 July, p 17) you say: "Whether or not you believe in the paranormal may depend entirely on your brain chemistry. People with high levels of dopamine are more likely to find significance in coincidences, and pick out meaning and patterns where there are none." But perhaps it is rather that insufficient levels of dopamine in the brains of sceptics prevent them from seeing what is actually there. Bellingham, Washington

Go away, ET From TomMarlow You suggest making no reply if we detect an alien civilisation for fear of oppression (17 August, p 5). But surely this cuts both ways. If all ET civilisations have the same fear, none will be sending out signals, making the whole SETI project futile. Saffron Walden, Essex

From Rob Moore Perhaps the lack of detectable ET communications is because they

have not been programmed in by the creators of our virtual world (27 July, p 48). Maybe this means that the simulation we live in isn't designed to go much beyond the point were we have the technology to observe ET. Does this mean we have reached theendofour useful lives and are about to get switched off? Sydney

black vintage cars on the road, you can understand that sometimes very old specifications are important. A difference of as little as o.oi per cent in the amount of light absorbed would be easily discernable to the owner. And the tonal quality of the black, such as a blue or brown undertone, is also very important. Bristol

From Yvan Dutil There is another reason why there have been very few SETI transmissions (17 August, p 27). Unlike passive SETI, you are 100 per cent certain not to receive a reply in your lifetime. Ste-Foy, Quebec

Pure dog dung

Silent teachers From Alan Boal Your article suggests that memorial services for medical school cadavers are uncommon (10 August, p 40). But there is also an annual event at Dundee University to give thanks to people who left their bodies to science. It is without doubt the busiest day of the year for the university's chaplains. One eulogy prepared by a student and read at the service described those who had chosen to donate their bodies as "silent teachers" who provide more than any book or computer-based simulation. Dundee

All shades of black From Richard Abbott The comment that the black paint from Halfords is suitable "for all shades of black" is actually a useful piece of advice, and not worthy of Feedback's scorn (10 August). There are over 2000 "shades" of black defined by the automotive coatings industry. Many of these are very similar but have different specifications from different companies, or the same company over a period of years. Once you notice the number of

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From TonyCovington, British School of Leather Technology Brian Robinson states that "pure" was a term for the dog excrement used in infusions to treat skins and hides, but I am more familiar with the spelling "puer" (17 August, p 28). Dog dung contains pancreatic enzymes which were used in solution to attack the noncollagenous proteins in skins or hides. This was a purifying rather than a curing step, to clean the material prior to tanning. It also means that biotechnology has been used in the leather industry for at least 5000 years. I have always been curious as to the origin of the term puer, although it is only one of many strange bits of jargon surrounding the art. I can only think that the job was so unpleasant that the "puermaster" left the handling of the materials to his lad, orpuerin Latin. Treating skins with dog dung was always called puering, and the use of infusions of bird guano was called "mastering". Happily, the dung treatment is now obsolete, and nowadays the same general process is called "bating", and typically involves manufactured bacterial or

pancreatic enzymes. The process that it's part of is one of humanity's oldest technologies. Northampton

Weapons on planes From MarkMacDiarmid Further to Rachel Cave's glass clubs (Feedback, 10 August), on a recent trip to Britain my partner and I were lolling about in the Qantas business lounge at Sydney airport. I decided to avail myself of the lavish fare spread out on a nearby sideboard, and noticed that alongside the handsome metal forks and spoons were plastic knives. Oh well, I thought, at least I'm safe from any evil-doers who want to run amok. Some hours later, as I was being served the first meal of the flight, I was appalled to find that I was provided with a metal knife. I had half a mind to jump up brandishing the offending item, bellowing my indignation at whoever would listen, but you'll be pleased to hear that I managed to sit quietly all the way to Singapore. There, I boarded a KLM flight for Amsterdam, and again found myself given a vicious looking stainless-steel knife, while my nail clippers were stashed in the hold. Katoomba, New South Wales

Humble words From Vom Hancock Finding "The Who" on Google is fun, given the way the search engine ignores "humble" words (Feedback, 3 August). But how about this? I recently wanted to acquire some CDs by a band headed up by Matt Johnson. The band's name? "The The". Cambridge Letters should be sent to: Letters to the Editor, New Scientist, 151 Wardour Street, London W1F 8WE Fax: 020 7331 2777 Email: [email protected] Includeyoursddressandtelephone number, and a reference {issue, page number, title)to articles. We reserve the right to edit letters. Reed Business Information reserves the right to use any submissions sent to the letters column or New Soenfetmagazine.inanyotherformat.

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I know what you'll do next summer What do galaxies, stockbrokers and style gurus have in common? A set of numbers describing everything they do. Does nature's hidden program mean we're all deeply predictable, asks John Casti WHEN was the last time you bucked a ! trend? Really swam against the tide? Chances are, you never really have - at least, not for long. But it's not your fault. You may not have as much free will as you think. Most of us are aware of our tendency to go with the herd. We tag along with fashions: our hemlines rise and fall, our trouser legs widen and narrow, or we buy technology stocks when others are doing the same. We accept that, much of the time, we're not being "individual". What we're not aware of is why. There are evolutionary arguments, of course: if you haven't enough information on which to base a judgement, the next best thing is to assume that the herd knows where it's going. But a mathematical analysis of our activities indicates that there maybe something deeper going on. We seem to be fated to act in a way that mimics patterns found elsewhere in nature. We already know that some actions of society appear to follow laws that often apply to otherwise completely unrelated phenomena in the Universe. The numbers behind the fractal shape of a snowflake can also describe our society's financial activities, for instance. Financial data is one thing, but why should the maths that describes a seashell's spiral also underlie our technological progress? Why can our shopping habits be described by the same rules that dictate how galaxies are spread through the cosmos? It's as though we are somehow programmed by mathematics. Seashell, galaxy, snowflake or human: we're all bound by the same order. Mathematical laws are already used to describe human activity, of course. There are various tools such as Bayesian theorems, power laws, hidden Markov processes and

cellular automata, just for starters. All of these have been used in modelling financial markets, with varying degrees of success - and popularity. But now an old mathematical idea, first dreamed up in the 19305, has come to the fore again and is proving itself more powerful than anyone ever thought possible. It has enabled people to make specific predictions about the financial markets, forecasts that are now unfolding with uncanny accuracy. The fact that this technique also has something to say about what it is to be human makes it all the more remarkable. To begin at the beginning, you have to go back to California during the Great Depression. Ralph N. Elliott, a Los Angeles accountant, is in frail health and unable to find work. While recuperating, he has plenty of free time to investigate the stock market and try to work out why it has just lost 90 per cent of its value over a three-year period. He becomes convinced that there are repetitive patterns within market indices such as the Dow Jones index. Of course, Elliott knows it's not really saying much to point out that the Dow Jones moves in cycles. What he needs to understand is how to characterise the kinds of cycles, and then to look for patterns within them. He realises that such an understanding would enable alert investors to predict the rising prices of a bull market, foresee the decline of a bear market and even anticipate great crashes such as those of October 1929. Elliot, a hands-on specialist in corporate financial rescue, was no stranger to market analysis or the ebbs and flows of business and eventually managed to fit together the pieces of a fascinating puzzle. Elliott's great leap forward was the realisation that the cycles don't originate within the financial markets, *

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"The connection between Elliott waves and the Fibonacci series links the stock market with other natural patterns and processes found in livingforms" but are a product of the humans that drive them. "Human emotions are rhythmical; they move in waves of a definite number and direction," Elliott observed. "The phenomenon occurs in all human activities, be it business, politics, or the pursuit of pleasure." And so, by analysing stock market data, he picked out certain fundamental rhythms. Today they are known as Elliott waves. The theory of Elliott waves is based on patterns of ups and downs, underpinned by a few basic principles. First of all, action is always followed by reaction: up is eventually followed by down. At this level, an Elliott wave cycle is composed of two waves, where a "wave" is simply a change - either an upward "impulse" wave, or a downward "corrective" wave.

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However, Elliott found that each wave isn't necessarily just a straight line. Instead, it can be subdivided into five smaller waves, so an impulse wave might actually consist of updown-up-down-up. Likewise, the data revealed that waves were sometimes subdivided into just three waves: down-up-down for a corrective wave, for example. So, on closer inspection, an up-down Elliott wave cycle is actually composed of eight waves. One slight complication is that the number of sub-waves within a given wave actually depends on whether that wave is with the overall trend or against it. So if the overall trend is downward, for example, then corrective waves in that trend have five sub-waves, and impulse waves have three (see Diagram, opposite). However, just as "zooming in" on an up-down pattern reveals eight smaller waves, zooming out shows that it can also be considered as a 2-wave component of a larger 8-wave cycle. So the wave principle is hierarchical in the sense that the same basic shape appears at all scales: each wave has

component waves and is itself a component of a larger wave. This self-similarity at different scales is the hallmark of fractal patterns, which are seen everywhere in nature in things like fern fronds, coastlines and blood vessels. So how many scales, or "degrees", of waves, sub-waves, and sub-sub-waves are there—how far can you zoom in or out? Elliott named nine degrees, from those lasting centuries to those lasting just hours. But the actual number of degrees may be limitless, since the same patterns show up even on one-minute graphs of stock prices, and are likewise presumed to operate over indefinitely large timescales. As you might expect, the area in which Elliott waves have been most extensively applied is in finance. For instance, the value of the Dow Jones between 1932 and the present can be broken down in terms of Elliott waves. If you can identify the waves and sub-waves and if know where you are on a wave, you know exactly where you're going next (see "Riding the wave"). For example, Elliott used his wave theory to announce, in the middle of the worst

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ELLIOTT WAVES IN THE STOCK MARKER An 8-wave cycle advances in five waves (the impulse wave) and declines in three (the corrective wave) CORRECTIVE WAVE

Every wave can be split into waves of a lesser degree

The impulse wave, marked with blue dots, lasts 70 years. The longerdegree cycles last around lit and 30 years. The final impulse wave lasts around 25 years

of the Second World War, that a multi-decade stock market rise was about to begin. And financial guru Robert Prechter did the same in the midst of recession in September 1982 by announcing that a "super bull market" had begun and forecasting a fivefold increase in stock values. In both cases, the Elliott waves enabled them to get it right. But Elliott waves are something more profound than just a money-making tool. They have a very close connection with the series of numbers known as the Fibonacci sequence, where each number is the sum of the two previous ones. This produces an infinite series of numbers: i, i, 2,3,5,8,13,21... The number of waves that comprise the Elliott patterns at each successive level of detail

"Is our behaviour somehow dictated by these numbers? Is what we dojusta natural process, like the way a snowflake or a seashell forms?" www.newscientist.com

are precisely the numbers of the Fibonacci sequence. It's easy to see why when you consider how the pattern builds up. The simplest expression of a corrective wave is a downward straight line, while that of an impulse wave is a straight line upwards. So a complete up-down cycle is just two waves. At the next level the corresponding number of corrective and impulse waves are 3 and 5, respectively: Elliott's theory says the downward line has 3 sub-waves, and the upward one has 5. The total cycle then consists of 8 waves, and we have the first six numbers of the Fibonacci sequence (see Diagram, p 32). This process continues indefinitely. The connection between Elliott waves and the Fibonacci sequence is intriguing, because it links the wave principle that underlies the stock market with other natural patterns and processes found in living forms. The Fibonacci sequence appears all over the scientific landscape: it describes the spiral patterns found in seashells and the DNA helix, as well as the number of spirals on pine cones and sunflower seed heads, to give just a few natural examples. It also crops up in fractals. According to Prechter, who produces a monthly publication called The Elliott Wave Theorist, these patterns reveal a direct connection between nature's numbers and all of human behaviour. Prechter believes the wave patterns are an organising principle for myriad social behaviours, ranging from newspaper sales figures to the fortunes of national leaders. ^

RIDING THE WAVE You can now buy software that will take any series of data, such as stock exchange figures or CD sales, and use pattern-recognition techniques to pick out the various Elliott patterns at different timescales. Spotting Elliott waves within the data is not an entirely mechanical procedure, but there are some rules of thumb that help. Here are just a few of the characteristics of a 5-wave rise: Wave 2 does not till below the starting level of wave 1 Wave 3 is not the shortest wave Wave