News this Week

Science  20 Oct 2006:
Vol. 314, Issue 5798, pp. 396
  1. EPIDEMIOLOGY

    Iraqi Death Estimates Called Too High; Methods Faulted

    1. John Bohannon

    A new estimate of the number of Iraqis who have died as a consequence of the U.S.-led invasion in March 2003 has ignited a firestorm of its own. At 400,000 to 800,000 deaths, the new number is at least 10 times higher than estimates cited by the Iraqi government and U.S.-led coalition. U.S. President George W. Bush immediately dismissed the study, characterizing its methodology as “pretty well discredited.” Other Administration officials charged that the study, released with significant publicity 4 weeks before U.S. midterm elections, was politically motivated. Researchers who spoke with Science disagree that the authors' motives are suspect but raise several questions about the methodology of the study, which was published 11 October in The Lancet.

    Counting the dead.

    Researchers attribute most of the estimated 400,000 to 800,000 Iraqi deaths to violent causes, including gunshots, air strikes, and car bombings, such as this one in Baghdad.

    CREDIT: ALI JASIM (IRAQ)/REUTERS

    Experts on both sides of the debate concede that it is notoriously difficult to get an accurate count of casualties in Iraq. The Iraqi Ministry of Health has estimated up to 40,000 violent deaths so far, based on death certificates reported by hospitals and morgues. That figure falls within the range published by Iraqi Body Count, an independent London-based group opposed to the war that compiles casualty numbers from media reports. There is little doubt that the real number of deaths is higher than this, because only a fraction of deaths are officially recorded or reported by journalists. But just how small is that fraction?

    The Lancet study, designed by researchers at Johns Hopkins University in Baltimore, Maryland, is based on a survey conducted between May and July by a team of 10 Iraqi health workers. (The Johns Hopkins researchers met with the Iraqi team twice across the border in Jordan to advise on the survey techniques.) The team visited 47 neighborhoods in 18 different regions across the country, going door-to-door and asking families about recent deaths. They collected data from a total of 1849 households containing 12,801 residents. For the 14 months before the invasion, the Iraqi families reported 82 deaths, an annual death rate of 5.5 per 1000 people. Within the same households, 547 people died between the start of the invasion and July of this year—an annual increase of 7.8 deaths per 1000. By applying this rate to the entire population of 27 million, the researchers conclude that 655,000 more Iraqis have died than would have if the invasion had never happened. About 8% of these extra deaths are attributed to deteriorating public health, but an estimated 601,000 are violent—56% from gunshots and about 13% each from air strikes, car bombs, and other explosions. The researchers calculate a 95% probability that the true number of violent deaths lies between 426,369 and 793,663.

    Many academics spoke up in defense of the study. “I too find the survey's estimates shockingly high, … [but] the choice of method is anything but controversial,” wrote Francesco Checchi, an epidemiologist at the London School of Hygiene and Tropical Medicine on 12 October on a humanitarian Web site. The statistical technique used, called cluster surveying, divides the population into different regions, neighborhoods, and households, in contrast to a random sampling of people on the streets.

    The method may be sound, but several critics question the way it was carried out in this study. Madelyn Hicks, a psychiatrist and public health researcher at King's College London in the U.K., says she “simply cannot believe” the paper's claim that 40 consecutive houses were surveyed in a single day. “There is simply not enough time in the day,” she says, “so I have to conclude that something else is going on for at least some of these interviews.” Households may have been “prepared by someone, made ready for rapid reporting,” she says, which “raises the issue of bias being introduced.”

    Lead author Gilbert Burnham, an epidemiologist at Johns Hopkins, counters that “40 adjacent households is entirely achievable in a day's work if well organized.” Les Roberts, also at Hopkins, adds that 80% of the 547 deaths were corroborated with death certificates. The fact that hundreds of thousands of death certificates seem to have gone unregistered by the Ministry of Health is no surprise, says Roberts, because “those have always been grossly underreported.”

    Neil Johnson and Sean Gourley, physicists at Oxford University in the U.K. who have been analyzing Iraqi casualty data for a separate study, also question whether the sample is representative. The paper indicates that the survey team avoided small back alleys for safety reasons. But this could bias the data because deaths from car bombs, street-market explosions, and shootings from vehicles should be more likely on larger streets, says Johnson. Burnham counters that such streets were included and that the methods section of the published paper is oversimplified. He also told Science that he does not know exactly how the Iraqi team conducted its survey; the details about neighborhoods surveyed were destroyed “in case they fell into the wrong hands and could increase the risks to residents.” These explanations have infuriated the study's critics. Michael Spagat, an economist at Royal Holloway, University of London, who specializes in civil conflicts, says the scientific community should call for an in-depth investigation into the researchers' procedures. “It is almost a crime to let it go unchallenged,” adds Johnson.

    Co-author Roberts is no stranger to such controversy. He led a smaller study of Iraqi casualties, published in The Lancet in 2004, that estimated 100,000 deaths. That work was criticized for relying on too few samples. This time, he says, “we took enough samples, and if anyone wants to verify our results, it's easy.” The study suggests that close to four times the number of deaths occurred in the first half of 2006 than in the first half of 2002, he says, “and anyone could simply pick four to six spots in Iraq and go to the local graveyards. The increase … should be obvious.”

    For now, Spagat says he is sticking with casualty numbers published by the United Nations Development Programme (UNDP). A UNDP survey of 21,668 Iraqi households put the number of postinvasion violent deaths between 18,000 and 29,000 up to mid-2004. “When a survey suggests so much higher numbers than all other sources of information,” he says, “the purveyors of this outlier must make a good-faith effort to explain why all the other information is so badly wrong.”

  2. ECOLOGY

    Report Warns of Looming Pollination Crisis in North America

    1. Constance Holden

    California almonds are a huge food crop in the United States, and land devoted to almond trees is expected to increase another 50% by 2012. But that growth depends in large part on availability of the almonds' pollinator, the honeybee.

    And honeybees are in trouble, according to a report on North American pollinators* unveiled this week by the National Research Council (NRC) of the National Academies. Although there is “no strong evidence for a current pollination crisis,” there may be one looming, reports an NRC committee led by entomologist May Berenbaum of the University of Illinois, Urbana-Champaign.

    The committee calls for better long-term monitoring of all pollinators, noting that few records exist for species other than honeybees. A study earlier this year documented decreasing pollinator diversity in Europe, and there are similar fears about what's happening in North America (Science, 21 July, p. 286). Last year, for the first time since 1922, California almond growers imported bees from Australia to service their trees because U.S. bee colonies are being decimated by a mite, Varroa destructor, which sucks the life out of larvae. According to the report, the mite, which first showed up in 1987, is even overshadowing the Africanized honeybee, which—adaptable, angry, pushy, and proliferative—has been steadily encroaching in the southern United States and muscling aside the gentler European honeybee population.

    Roughly one-third of the North American diet comes from food—fruits, vegetables, seeds, and nuts—that rely on animal pollinators, which include beetles, butterflies, flies, bats, hummingbirds, and bumblebees. But the king of pollinators is Apis mellifera, the European honeybee. Much preferred over its African cousin, it's a “generalist” that pollinates a huge variety of crops. It is also highly social and thus easy to muster.

    Stamps of approval.

    Next spring, the U.S. Post Office will issue these and other stamps depicting pollinators.

    CREDIT: UNITED STATES POSTAL SERVICE

    The NRC report notes that just as modern agriculture relies too much on monocultures, there is too much reliance on honeybees, which beekeepers truck around from one crop to another, like migrant workers. Almonds are particularly vulnerable, says Kevin Hackett of the Agricultural Research Service, because their trees flower early in the year when honeybee colonies are weakened from winter mite infestations. He says mites have caused the price of bee rental for almond growers to go from about $30 to as much as $150 per hive.

    NRC calls for more research on the mite problem, noting that Varroa have become resistant to antibiotics and pesticides. It's been difficult to breed mite resistance into the bees, in part because of the queens' loose mating habits. Hence the need, says the committee, to develop “non-Apis” pollinators such as the alfalfa leaf-cutter bee, which doesn't have a mite problem.

    The committee also advises that the U.S. government establish discovery surveys for wild pollinators of U.S. crops and of rare or endangered plants. The NRC report adds that beyond increased research and data-gathering, simple steps, such as growing wildflowers in golf-course roughs, can help keep a diverse array of pollinators in business.

    Adding to the buzz surrounding the report, the 3-year-old North American Pollination Protection Campaign (http://www.pollinator.org/) sponsored a symposium this week at USDA to discuss better management of pollinator resources worldwide.

  3. EUROPEAN FACILITIES

    Panel Draws Up Shopping List

    1. Daniel Clery

    European researchers have compiled a wish list of 35 large-scale projects that they would love to see built over the next 2 decades. The projects, which must be internationally important and open to all European researchers, include a database on the impacts of population aging, a polar research ship, and an underwater neutrino observatory. John Wood, head of the U.K.'s Central Laboratory of the Research Councils and chair of the panel that drew up the road map, says the list released this week will help potential funders “to see what's out there, what's likely to come up, and when.” The hope is that it will become an informal priority list of international European projects.

    The road map was put together by the European Strategy Forum on Research Infrastructures (ESFRI), a meeting place for officials and senior scientists from the European Union and individual nations to work out collaborations on big projects. Projects for the road map “had to demonstrate added value at a European level,” says Ruth Bar rington, head of Ireland's Health Research Board, who chaired the road map's biological and medical science working group, one of three such subgroups. Projects in space science and high-energy particle physics were excluded from the road map because they fall under the purview of the European Space Agency and CERN, the European particle physics lab near Geneva, Switzerland.

    New life.

    The ESFRI road map includes upgrades to the European Synchrotron Radiation Facility (top) and the Institut Laue-Langevin neutron source.

    CREDITS (TOP TO BOTTOM): ASSA; ILL/ARTECHNIQUE

    The projects range in cost from the €9 million ($11 million) European Social Survey to the €1.2 billion Facility for Antiproton and Ion Research. Although the road map gives no guarantee of funding, it “will give the message [to researchers] that they must get organized at a European level if they're going to get new infrastructures,” says Carlo Rizzuto, head of the Sincrotrone Trieste laboratory in Italy, who led the road-map working group on physical sciences and engineering.

    Although big facilities in the physical sciences are commonplace, ESFRI tried hard to work life sciences, social sciences, and humanities into the mix. “We took a wide-ranging decision that we must include all disciplines,” says Barrington. Bjørn Henrichsen of Norwegian Social Science Data Services, who headed the social science and humanities working group, says this is the first time social sciences were treated the same as natural sciences in such a process. But despite ESFRI's efforts to be inclusive, several areas of research are not represented in the list, such as geology, engineering, energy research, psychology, and economics. “I hope communities will become excited by the vision of the road map” and bid to be included in future versions, says Wood.

    Rizzuto hopes that the road map will help promote the idea of open-access facilities. “This mode of infrastructure has existed since the Middle Ages, but it still needs to be explained to politicians,” he says. Barrington thinks the “convergence of thinking” that went into the road map and the support from senior scientists and government officials has been “absolutely remarkable.”

    ESFRI members will present the road map next spring at a Paris meeting of the Organisation for Economic Co-operation and Development on research infrastructure. Will that meeting result in a world road map? “Wouldn't that be lovely?” says Wood.

  4. HIGHER EDUCATION

    A German Ivy League Takes Shape

    1. Gretchen Vogel

    BERLIN—In world rankings of universities, Germany's institutions come out solidly in the middle of the class. The 2006 list drawn up by the Times Higher Education Supplement, for example, puts the University of Heidelberg at number 58, and that's the best of any German university. Last year, the German government launched an “excellence initiative” that would boost at least a few universities to world-class status—a German Ivy League. Schools around the country have applied for the €1.9 billion ($2.38 billion) budgeted to the initiative, and the first results of this competition, announced last week, give Munich major bragging rights: Two of the three universities singled out as potential topflight schools are the Technical University Munich (TUM) and the Ludwig Maximillian University (LMU), also in Munich. The third is the Technical University (TU) Karlsruhe, in southwest Germany. In a surprise, Heidelberg didn't make the cut—at least this time.

    Top plans.

    The Technical University Munich is one of three winners in Germany's elite university competition.

    CREDIT: THORSTEN NAESER

    The idea of a few top universities that attract the best and the brightest is hardly new in most Western countries, but in Germany it challenges the status quo. For decades, official policy has been that the state-financed, tuition-free universities should all be roughly comparable in quality and prestige. But after years of flat or even shrinking budgets, universities are largely seen as burdened with aging infrastructure, growing student loads, and a hierarchical faculty system that leaves little room for up-and-coming researchers. Instead, many of Germany's best scientists are concentrated at the nonacademic Max Planck institutes and at research centers of the government-funded Helmholtz or Leibniz associations.

    The new initiative introduces a taste of the interuniversity competition that keeps U.S. schools on their toes, says Peter Strohschneider, head of the German Science Council: “We are erasing the popular fiction that all German universities are equal.”

    Still, when former science and education minister Edelgard Bulmahn announced her idea for a German “elite university” in early 2004 (Science, 9 January 2004, p. 155), some politicians and academic administrators worried that lavishing money on a few schools would leave the rest of the chronically under-financed system to decay. Others noted that investing the planned €1.9 billion over 5 years could hardly create a Harvard or Stanford—which have yearly budgets of $3 billion each. And some feared that politicians would water down the program by spreading the funding throughout the country.

    Indeed, in a compromise worked out after more than a year of wrangling between Germany's federal and state officials, the program was widened to include three award categories: €1 million a year for new graduate schools, €6.5 million for so-called excellence clusters designed to spark cooperation between universities and neighboring research institutes, and a top award of about €13 million annually for schools that develop promising strategies to “advance top-level research.” In the results announced on 13 October, 22 universities were awarded the extra funding for new graduate school programs and excellence clusters. TU Karlsruhe, TUM, and LMU were among those winners, but they were also tabbed for the most-coveted university-wide award.

    The selections quieted some critics who predicted that the money would flow based on political calculations instead of academic criteria. Indeed, at last week's meeting between 26 scientific reviewers and the 17 state and federal science ministers, several politicians complained that the scientists—who had a majority of the votes—gave them no voice in the final decision. After a few heated comments, however, the politicians accepted the scientists' recommendations without dissent. Although there were scattered winners in Berlin, Hanover, and Kiel, most of the funding will flow to schools in the southern half of the country. The University of Dresden was the only school in the former East Germany with any winning projects. Federal science minister Annette Schavan acknowledged the tension behind the awards, but she called the unanimous vote “a sign of confidence from the politicians” in the scientists' judgement.

    German Chancellor Angela Merkel, who trained as a physicist, also defended the awards, noting that the long-term research investments made by southern regions paid off. “If the south is better, then that's the way it is,” she told journalists.

    TU Karlsruhe, with 18,000 students, played up its long-standing cooperation with the Forschungszentrum Karlsruhe, an institute governed by the Helmholtz Association, with 1400 scientists in materials science, environmental sciences, energy, and health. The two bodies will together create the Karlsruhe Institute of Technology, modeled on the Massachusetts Institute of Technology, which is much admired across Europe for attracting top talent and spinning off patents and products. Rector Horst Hippler notes that the extra €21 million a year will be helpful, but much more important, he says, will be the image boost the school hopes to receive.

    TUM called its concept “the entrepreneurial university” and says it plans to increase cooperation with for-profit partners. It also plans to further develop its new Institute for Advanced Studies, modeled on the one in Princeton, New Jersey, which will free some of its top professors from part of their teaching loads.

    LMU, with 47,000 students, says it will use its extra funds for a multidisciplinary Center for Advanced Studies, focused on “problem-oriented” research. It also plans to boost its private fundraising—still a rarity among German universities.

    Heidelberg and others disappointed by this week's announcement will have another chance next year, when an additional €1 billion will be distributed in a second round of funding.

  5. ATMOSPHERIC SCIENCE

    Pollute the Planet for Climate's Sake?

    1. Richard A. Kerr

    The source of the proposal was almost as remarkable as the idea itself. In the August issue of Climatic Change, Paul Crutzen, who won the Nobel Prize for helping work out the chemistry of ozone destruction in the stratosphere, resurrected an oft-disparaged suggestion: Create a global haze by spewing megatons of sulfurous debris into the stratosphere to shade the planet and rein in greenhouse warming. “A few years ago, I would have said, ‘I'm not touching that,'” says the Max Planck Institute for Chemistry researcher. Now, however, he finds the “grossly disappointing international political response” to global warming's threat so disturbing that the notion of deliberately contaminating the stratosphere looks less and less crazy.

    Bad idea, respond some climate scientists. It would be applying a Band-Aid to the symptom while continuing to stoke the problem with ever-increasing greenhouse gas emissions. Best not even to talk about it. Worth looking at, say others. Given the surprises that may be lurking in the greenhouse, desperate countermeasures could come in handy. Thanks to Crutzen's stature, this scientific and ethical debate is blossoming as the climate community begins to take a hard look at geoengineering climate.

    Supporters of at least studying the idea seem to have some momentum for now. “Crutzen's paper created some sort of phase change, making geoengineering a respectable topic of conversation,” says climate modeler Kenneth Caldeira of the Carnegie Institution Department of Global Ecology at Stanford University.

    Geoengineering as a fix for global warming has been a topic of usually sotto voce conversation since the 1970s, when the Soviet climatologist Mikhail Budyko suggested Earth could be cooled by adding tiny sunlight-reflecting particles to the stratosphere. Nature soon served up a couple of striking examples of how it might be done when the volcano El Chichón erupted in 1982 and Mount Pinatubo erupted in 1991. The long-lived stratospheric debris of Pinatubo—water droplets laced with sulfuric acid derived from the volcano's sulfur—reflected enough sunlight back into space to cool Earth on average 0.5°C for a year or two following the eruption. That's about the size of the warming of the past century.

    A volcanic chill.

    Humans might loft sulfur into the stratosphere to counteract global warming; Mount Pinatubo did in 1991.

    CREDIT: BULLIT MARQUEZ/AP PHOTO

    Pulling off a “human volcano” to counteract global warming would take some wherewithal. Pinatubo put up 10 million tons of sulfur, most of which fell out of the stratosphere within 2 or 3 years. So humans looking to cool the greenhouse by stratospheric shading would have to send millions of tons of sulfur tens of kilometers into the air every year, perhaps century after century, in order to renew the continually depleted shield of haze. The resulting acid rain would be minor compared to current levels, say proponents. People have discussed delivery methods from balloons, big guns, and giant planes. To ease the burden of lifting megaton masses, the late Edward Teller—father of the hydrogen bomb and “Star Wars” missile defense advocate—proposed substituting more efficient reflectors for sulfur, something metallic and perhaps engineered like tiny retroreflectors.

    Daunting practical aspects aside, the latest—although preliminary—climate modeling hints that shading the globe to counteract greenhouse warming could actually work. In this issue of Science (p. 452), climate researcher Tom Wigley of the National Center for Atmospheric Research in Boulder, Colorado, reports that in a simple, so-called energy-balance model, firing off a Pinatubo eruption every 2 years or so would be enough to counteract the projected warming indefinitely. And so far in sophisticated general circulation models (GCMs), “all the simulations have suggested it would basically work,” says Caldeira, who has run many such simulations. Crutzen, who has been cooperating on other GCM simulations, agrees. “It's very tantalizing,” he says. “It just looks too good.”

    That's what worries many climate researchers. “I refuse to go down that road,” says biogeochemist Meinrat Andreae of the Max Planck Institute for Chemistry in Mainz, Germany. “You're papering over the problem so people can keep inflicting damage on the climate system without having to give up fossil fuels.” That option could be so attractive that “the biggest risk of geoengineering is it eliminates pressure to decrease greenhouse gas emissions,” says Caldeira.

    Other critics note that if a shading effort faltered, decades or centuries of greenhouse warming would envelop the world in a couple of years. Nonclimate effects of carbon dioxide, such as acidification of the oceans, would continue apace despite the shading. And then there's the complexity of the climate system. Recent model simulations aside, “we don't know exactly what is going to happen” once stratospheric shading begins, says climate modeler Lennart Bengtsson of the Max Planck Institute for Meteorology in Hamburg. All things considered, many climate scientists would just as soon see geoengineering of the climate problem returned to obscurity.

    Ignoring the idea has its appeal, admits climate modeler Michael MacCracken of the Climate Institute in Washington, D.C., but “the question comes up so many times, you have to be addressing it.” And studying the possibility wouldn't mean it would have to be done, says geoscientist Michael Oppenheimer of Princeton University. Quite the opposite. The idea of sucking the greenhouse's carbon dioxide into the deep sea by fertilizing ocean phytoplankton with iron only went away, he notes, after small-scale experiments showed it wouldn't work as proponents hoped (Science, 11 August 1995, p. 759).

    A human volcano has obvious drawbacks, concedes Ralph Cicerone, an atmospheric scientist and president of the U.S. National Academy of Sciences, but they may appear to dwindle in the future. If warming took off far faster than expected, for example, and serious efforts to cut back greenhouse gas emissions were failing, a stopgap approach would become more attractive, he says. A scientific understanding of the shading option should be in hand in case that happens, he argues; scientists could study geoengineering while agreeing not to carry it out on a large scale. The U.S. Department of Energy seems to agree. Officials there, emboldened by Crutzen's paper, are taking a renewed interest in stratospheric shading, arranging workshops and a meeting next year while considering releasing a report on the subject.

  6. PHYSICS

    Voilà! Cloak of Invisibility Unveiled

    1. Adrian Cho

    Just 5 months after predicting it should be possible, a team of physicists has produced a cloaking device that renders an object invisible—at least when viewed in microwaves of a particular wavelength.

    Where'd it go?

    This cloaking device is practically invisible—if you see the world in microwaves with a wavelength of 3.5 centimeters.

    CREDIT: DAVID SCHURIG

    The cloak is hardly perfect: Instead of an all-concealing sphere, it's a ring that works only for microwaves zipping along in a plane. The microwaves must also be polarized perpendicular to the plane. And even then, the cloak reflects some of the waves and casts a slight shadow. Nevertheless, “it's a very good achievement,” says Ulf Leonhardt, a theorist at the University of St. Andrews in the United Kingdom. “It's surprising that it's as simple as it is and that it works so well.”

    The cloak embodies the theory laid out by theorist John Pendry of Imperial College London and experimenters David Schurig and David Smith, who work in the electrical and computer engineering department at Duke University in Durham, North Carolina. In May, the team showed that, in principle, it's possible to ferry electromagnetic waves such as light around an object by surrounding it with a “metamaterial”: an assemblage of tiny rods and C-shaped rings (Science, 26 May, p. 1120). The waves would then pass as if the object weren't there, rendering it invisible.

    The electromagnetic waves cause the electrons in the rings and rods to slosh, and the sloshing, in turn, affects the speed at which the waves travel through the material. If the speed varies in the right way within the cloak, the waves will curve around the object. The theory predicts only how the speed of the waves must vary; it leaves it to experimenters to design the material.

    When Schurig, Smith, and colleagues worked out the details, they found that their two-dimensional device required only C-shaped copper rings nestled side by side. The team also simplified the parameters specified by the theory. The changes made the metamaterial easier to build but also left the cloak slightly reflective, as the team reports online this week in Science (www.sciencemag.org/cgi/content/abstract/1133628). “The goal of this paper was to demonstrate that we more or less have the mechanism and that we can design the materials to the parameters,” Schurig says.

    Even the simplified cloak is a significant advance, says Costas Soukoulis, a theorist at Iowa State University in Ames and the U.S. Department of Energy's Ames Laboratory. “This is very, very important that experiments have produced what theorists had predicted,” Soukoulis says. Microwave cloaks might be useful for eluding radar, he says.

    It may take years for researchers to make a cloak for visible light. Still, most believe such a thing should be possible now that a cloak for microwaves has been built. After all, not seeing is believing.

  7. ECOLOGY

    A Rescue Effort for Tsunami-Ravaged Mangrove Forests

    1. Richard Stone

    KOH PHRA THONG, THAILAND—Fishers in longboats putter down a waterway in a mangrove forest on Phra Thong Island, a lesser adjutant soaring gracefully overhead. The tsunami of December 2004 dealt a vicious blow to Phra Thong, in the Andaman Sea, wiping out one of three villages and wrecking tropical forests and savanna. Now, the island's rebounding mangroves exemplify how ravaged coastal ecosystems can be restored, and how rare species such as the lesser adjutant—a black-and-white member of the stork family with a 2-meter wingspan—might mount a comeback.

    At a 31 October gathering of tsunami donors at the United Nations, the World Conservation Union (IUCN) and the U.N. Development Programme are planning to unveil a 6-year, $62 million initiative called Mangroves for the Future (MFF). Its goal is to replicate success stories like Phra Thong by replanting mangroves, rebuilding sand dunes, restoring sea-grass beds, and otherwise rehabilitating ecosystems in 12 tsunami-hit nations. “It's a tiny amount of money” compared to the $8.25 billion committed so far to post-tsunami reconstruction, says Lucy Emerton, head of IUCN's Ecosystems and Livelihoods Group. But for the 640 million people living within 100 kilometers of the coast in countries involved in the initiative, she says, “the payoff is potentially huge.”

    Mangrove forests shelter wildlife, serve as a source of food, herbs, and firewood, and act as a buffer against wind and waves. Although Asia boasts nearly 40% of the world's mangrove coverage, it was losing the fragile wetlands at an alarming rate even before the tsunami: Between 1980 and 2000, India, Indonesia, Sri Lanka, and Thailand lost nearly a third of their total mangrove area, IUCN notes. Clearance for settlements and conversion to shrimp farms are major reasons for the declines. “So much of what we're seeing is the cumulative effect of decades of neglect and bad policies that the tsunami brought into sharp focus,” says Emerton. On Phra Thong, mangrove trees were clear-cut to make charcoal until Thailand banned the widespread practice in 1991, says IUCN's Somsak Soonthornnawaphat. As a result, over the past 2 decades, mangroves in Phra Thong, off the Kra Isthmus connecting Thailand and Malaysia, have been growing back.

    Tsunami damage was magnified in areas with degraded coastal ecosystems. On Sri Lanka's south coast, for instance, one hotel that had leveled a sand dune “suffered enormous damage from the tsunami,” Emerton says, while another nearby that had retained its dune suffered little. The simple lesson, she argues, is that intact ecosystems help protect coastal infrastructure.

    Mangroves are resilient to wave action, yet the tsunami overpowered many forests, including one in southern Phra Thong. (An eastern forest emerged mostly unscathed.) IUCN is working with Thai authorities to replant mangroves there and set up nurseries under a recovery plan crafted with the Swiss Agency for Development and Cooperation.

    As part of this strategy, the Moklen people, or “sea gypsies” who island-hopped before settling on Phra Thong in the early 1900s, have demarcated a “community mangrove forest” in which fishing, cutting trees, and dumping oil are prohibited. IUCN and other agencies have helped the Moklen augment their food supply through organic farming of plants such as basil and galangal that thrive in sandy soil. “Before the tsunami, we only knew about the sea,” says Galaya Petchsai, a Moklen in Thung Dap village. She and other Moklen trap crabs and squid to trade for rice and other goods; the introduction of gardens increases their self-sufficiency, says Somsak.

    Spiritual joy.

    A Moklen boatsman prepares to head out to sea via a protected mangrove forest on Phra Thong Island. A new initiative intends to replicate the successful restoration of mangroves here in other tsunami-hit areas.

    CREDIT: MUTSUMI STONE

    In addition to replicating the strides made at Phra Thong, MFF intends to fund an updated assessment of mangrove distribution in the countries hit by the tsunami. “It's a huge gap,” says Emerton. Another goal is to strengthen the science of ecosystem restoration. After the tsunami, “there were a lot of well-intentioned but misguided attempts at mangrove restoration” throughout Southeast Asia, Emerton says. “A lot of money went into trying to plant mangroves where they can no longer grow or could never grow.”

    An MFF work plan will be presented to donors at the 31 October meeting, hosted by former U.S. President Bill Clinton, U.N. special envoy for tsunami recovery. Projects will begin in January. “We don't want to lose the momentum,” Emerton says. “There is a limited window of opportunity to persuade countries and donors that they should be investing in ecosystems.”

    For the Moklen, MFF should please the gods. Many believe the tsunami was divine retribution for how people harmed the land. “Now that there is no more cutting or destroying,” says Petchsai, “maybe the spirits are happy.”

  8. GENETICS

    Gene Offers Insight Into Macular Degeneration

    1. Jean Marx

    Jean Marx

    Within the past year, researchers have begun identifying the gene changes underlying age-related macular degeneration (AMD), the common eye disease that can eventually rob people of their vision. Some of the responsible genes are involved in inflammatory responses, which can cause tissue damage if not properly controlled (Science, 24 March, p. 1704). Two reports, published online this week by Science (www.sciencemag.org/cgi/content/abstract/1133807 and www.sciencemag.org/cgi/content/abstract/1133811), now point to the possible involvement of another gene—and another pathogenic mechanism—in AMD development.

    Vision thieves.

    Abnormal blood vessels that grow into the macula of the retina can leak (white arrows), leading to retinal detachment (black arrows) and blindness.

    CREDIT: A. DEWAN ET AL., SCIENCE

    Josephine Hoh of Yale University School of Medicine and her colleagues came upon the new candidate, known as HTRA1, by studying a group of Chinese patients who have AMD's more severe “wet” form, which is caused by the abnormal growth and breakage of blood vessels in the macula, the central part of the retina. At least in Caucasian populations, wet AMD often occurs in patients who first develop drusen, abnormal macular deposits of proteins and other materials. But the 96 Chinese patients Hoh examined had few or no drusen. They “go directly into the wet form,” she says.

    The Yale team ultimately found a single-nucleotide polymorphism (SNP)—a change of one DNA base—on chromosome 10 that distinguished the patients from people without AMD. Similarly, Kang Zhang and his colleagues at the University of Utah School of Medicine in Salt Lake City have found an association between the same SNP and AMD, but in a Caucasian population whose wet AMD is compounded by a large amount of drusen.

    This is not the first time this chromosome region, known as 10q26, has turned up in screens for AMD genes. For example, last year Michael Gorin's team at the University of Pittsburgh School of Medicine in Pennsylvania reported that 10q26 contains three potential AMD genes, PLEKHA1, LOC387715, and HTRA1 (also known as PRSS11). At the time, Gorin says, his analysis indicated that LOC387715, a putative gene of unknown function, showed the strongest linkage to AMD, a conclusion that has received support from other researchers.

    The work of Hoh's and Zhang's teams suggests that HTRA1 is the better candidate. Both teams found the suspicious SNP within HTRA1's regulatory sequences, and preliminary biochemical studies by the Yale group indicate that the SNP increases production of HTRA1's protein. Consistent with that finding, Zhang and his colleagues have detected elevated expression of the gene in retinal tissue from four deceased AMD patients who carried the high-risk HTRA1 variant.

    What's more, the gene appears to be involved in the development of the light-detecting cells of the retina. Earlier this year, Anand Swaroop and his colleagues at the University of Michigan, Ann Arbor, showed that its expression increases just as the cells begin to take on their final form. “I think it's going to be an important gene,” says Swaroop, who has his own as-yet-unpublished evidence linking it to AMD. “HTRA1 is a great [AMD] candidate,” Gorin agrees.

    The gene encodes a protein-splitting enzyme, hinting that it might contribute to retinal damage. The enzyme also interacts with other proteins, such as TGF-β, that are involved in new blood vessel growth.

    Still, neither Swaroop nor Gorin is ready to give up on a possible role for LOC387715 in AMD. “One has to do a lot more work to demonstrate that a SNP is associated with causality” and is not just a disease-gene marker, Swaroop says. But if the HTRA1 link holds up, researchers will have a new route to explore as they attempt to understand—and develop better diagnostic methods and therapies for—wet AMD.

  9. SCIENTIFIC PUBLISHING

    MEDLINE Supplements Must List Corporate Ties

    1. Jocelyn Kaiser

    Stepping into the fray over conflicts of interest in biomedicine, the National Library of Medicine's (NLM's) MEDLINE abstracts database will soon begin barring journal supplements that don't include financial disclosure statements.

    At issue are special volumes that often focus on a specific topic. James Marcetich, head of the MEDLINE index section, says NLM noticed in the past year that of the 1500 or so supplements processed each year, about 4% of all 2005 journal issues, a growing number were funded by drug companies but did not disclose that the companies had paid some authors to write articles about their products. “It just left a terrible impression,” he says.

    When the new policy goes into effect in January 2007, supplements will have to describe authors' relevant corporate ties or else they won't be listed. NLM is even including nonprofit sponsors after the watchdog group Center for Science in the Public Interest (CSPI) complained this month that a June supplement on dietary salt in the Journal of the American College of Nutrition lacked disclosures. The issue was paid for by a nonprofit that gets much of its funding from companies.

    Meanwhile, CSPI's Merrill Goozner says he's pondering whether to ask NLM to extend the policy to all articles and to note disclosures in abstracts. Marcetich questions whether that's necessary, noting that regular journals are already screened for quality—including disclosure policies—before they're listed in MEDLINE.

  10. GEOPHYSICS

    The Day the Land Tipped Over

    1. Richard Stone

    Indonesia's major earthquake last year tilted Nias Island like a seesaw, disrupting villagers' lives and pointing to future dangers

    Sunken city.

    Villagers in Haloban, on Tuangku, one of the Banyak Islands, must cope with daily flooding.

    CREDIT: KERRY SIEH AND ARON MELTZNER

    NIAS, INDONESIA—Jolted awake late in the night of 28 March 2005, Ahmad Chatib staggered outdoors to find fissures in the ground snaking from the beach up to his wooden house. He and others in Tagaulei, a seaside village on Nias Island off Sumatra's west coast, didn't hesitate. “We took our children and ran,” says Chatib, a former village head. Fresh in memory was the tsunami that 3 months earlier had claimed more than 160,000 lives in Sumatra's Aceh Province, 500 kilometers to the north. Of Tagaulei's couple of hundred residents, all but four—two mothers with infants who moved too slowly—escaped. Within an hour, most homes had been swallowed by the sea.

    It wasn't a tsunami that wiped Tagaulei off the map but subsidence caused by a rupture of the Sunda megathrust, the subduction zone that parallels Sumatra's west coast, 25 kilometers below the village. The great 2005 Nias-Simeulue fault break, which generated an earthquake with a magnitude of 8.7, instantly yanked down Nias's southeast shore some 30 centimeters. The earthquake's sustained shaking then made vast stretches of beach liquefy and spread, lowering the coast by another meter or more in places and leading to the inundation of buildings during high tide. Erosion since the quake has erased most vestiges of the once-picturesque village. On Nias and nearby islands, “places with minor subsidence are being massively rearranged,” says Richard Briggs, a geologist at the California Institute of Technology in Pasadena and member of a Caltech-Indonesian Institute of Sciences (LIPI) team that has spent a decade probing the region's tectonics.

    While the quake lowered southeast Nias, it lifted parts of the island's northwest coast nearly 3 meters, thrusting coral reefs into the air and extending the shoreline by hundreds of meters in places. Although such upheavals go hand in hand with a major earthquake of this kind, the Caltech-LIPI team, led by paleoseismologist Kerry Sieh, has used painstaking geodetic measurements to put together one of the finest-grained maps of seismic deformation. The portrait of Nias reveals in unprecedented detail how subsidence and uplift can utterly remake a landscape. “The ecological changes are profound,” Briggs says.

    Out of their depth.

    Near Lahewa, algae clinging to an uplifted reef mark the extent of high tide.

    CREDIT: DANNY HILMAN NATAWIDJAJA

    The severe warping of Nias offers an unsettling preview of what may await central Sumatra's west coast, including the major city of Padang. It faces a segment of the Sunda megathrust that the Caltech-LIPI team says is likely to rupture within the next few decades (see sidebar, p. 408). If a massive slip does occur, models suggest that the coastline around Padang would subside tens of centimeters, in a reprise of the devastation in Banda Aceh, which subsided by an average of 50 centimeters during the 2004 earthquake. Faced with that bleak outlook, Indonesian authorities must assess the feasibility of girding coastal structures against the subsidence and uplift of future megaquakes, says Danny Hilman Natawidjaja, a geologist at LIPI's Research Center for Geotechnology in Bandung. “It's important, absolutely, to do this,” he says.

    The social consequences of the 2005 catastrophe for islanders whose homes straddle the Sunda megathrust will take years to overcome. The region's economy lies in tatters. On Nias, patchy reconstruction efforts have left Chatib's family and hundreds of others living in tents and other temporary shelters. In the nearby Banyak Islands, only a few kilometers from the quake's epicenter, primary, or tectonic subsidence during the earthquake pulled the land down as much as a meter in some areas. There, to compensate for regular flooding, villagers have built elevated wooden walkways, as in Venice, and retreat to upper floors when the water creeps in. “I'm not sure that we in the West would put up with this for long,” says Briggs.

    Vanished mangroves

    On a wet September morning, the 3-hour drive by minivan from Nias's main town, Gunung Sitoli, to the northwestern port of Lahewa winds across hills verdant with coconut palms, banana trees, and cocoa trees from which mottled yellow, tear-shaped pods hang like Christmas tree ornaments. It's also a trail of tears. The 2005 earthquake, which released more than a century of pent-up strain in the subduction zone, leveled many homes and rearranged aquifers, causing some wells and rivers to run dry. Problems with water supply in coastal areas are “widespread,” says Briggs, who has chronicled deformation of the altered landscape.

    Electricity was out for 3 months, according to Ahmad Yani, a businessman from Gunung Sitoli. After power was restored, it took a couple more months for Nias's survivors, wearing surgical masks against the stench of rotting flesh, to clear the rubble. All the while, powerful aftershocks terrified many into believing that Nias would just sink and disappear. “A lot of people fled the island,” says Yani.

    A few kilometers east of Lahewa, the road bends around a wide, sandy beach. “Before the earthquake, this was all mangroves,” says Imam Suprihanto, an independent marine biologist and divemaster based in Jakarta who collaborates with the Caltech-LIPI team. Now the beach is bare; the mangrove forest, which had helped prevent erosion and shelter wetland creatures, was wiped out by an uplift of roughly 2 meters, and the shore these days extends several hundred meters farther toward the sea than it did before the earthquake tilted the land. Megaquakes in the region have wreaked similar havoc before. Measurements show that the Mentawai Islands off the coast of Padang rose 0.8 meter in 1797 and 2.8 meters in 1833, says Mohamed Chlieh, a geodynamic modeler at Caltech.

    Seismic shift.

    When a 400-kilometer-long stretch of the Sunda megathrust ruptured on 28 March 2005, the slip yanked down eastern Nias while thrusting up the island's west coast.

    CREDIT (BOTTOM): R. BRIGGS/CALTECH; OBLIQUE SHADED RELIEF: NASA WORLD WIND/BLUE MARBLE; ILLUSTRATION: A. STONEBRAKER/SCIENCE

    Some residents of Lahewa lost their livelihoods as well as their homes. The uplift transformed the harbor and surrounding beaches into an otherworldly vista of exposed coral reef colored in somber shades. “It must have been amazing and startling to see what must be among the rarest of sights, an entire living reef and most of its occupants high and dry in seconds,” says Briggs. Sudden sea-floor uplift generated the massive 2004 tsunami. The 2005 Nias quake triggered a smaller tsunami, roughly 2 meters high when it came ashore on Nias. But the island's uplift reduced inundation along the northern shoreline, which contributed to a much lower death toll in 2005—approximately 1300—than that of the 2004 quake, says geophysicist Mikio Tobita of the Geographical Survey Institute in Tsukuba, Japan. His group's satellite radar imagery of uplift and submergence patterns jibed with Sieh's team's laborious field measurements.

    In Lahewa harbor's former seabed, coral crackles underfoot like tinkling glass. Some microatolls of the coral genus Porites are taller than a minivan; the Caltech team zeroed in on these as records of uplift in 2005 and earlier quakes (Science, 31 March, p. 1897). Where fishing boats were once moored, hermit crabs and mudskippers skitter in their tidal pools. The earthquake shrugged a concrete jetty off its pillars, which now jut at odd angles. In the days after the quake, waves pulverized the beached fishing boats. Only a few larger vessels at sea escaped intact.

    The destruction of the harbor was a cruel blow. At a fish market once lapped by the harbor's waters but now several hundred meters inland, sales have been dismal. Relief agencies donated replacement boats, but most fishers have taken construction jobs, says Syaharfani Aceh, a fisher. And those who still fish “are afraid to go far out to sea,” he says, because uplifted corals just below the surface, most yet to be charted, pose a navigation hazard. Before the earthquake, fishers tended to put to sea at night, when catches are greater. So pervasive is the fear of another quake, Aceh says, that now they are afraid to leave their families alone after dark. And even moving the diminished stock is hard. “It's like the disaster just never stops for the fishermen and their families,” says Briggs.

    An endurance test

    The earthquake destroyed the road to Tagaulei, so the only way to reach it now is by a half-hour ride in a skiff from Bozihona, a village up the coast. Several beachfront homes in Bozihona, which also subsided, are half-buried in muck and sand. But its easier access allowed the Association of Medical Doctors of Asia (AMDA) to quickly erect 30 replacement homes here last July.

    Approaching Tagaulei's new beach, the boatman cuts his engine, and the skiff drifts past a few dark, wooden posts poking above the waves—all that remains of beachfront homes. As the skiff is hauled ashore, a shirt-less man in his 30s ambles over. Arman Aceh, a former fisher, points out to sea at a wall-less house frame sticking up from the waves—the only structure still with a roof. “That's my home,” says Aceh, teeth stained orange from a mix of areca nut and chalk, wrapped in betel leaf, bulging inside his cheek. He says there were houses even closer to the pre-earthquake shoreline, about 300 meters out to sea from the present one; they have vanished.

    Joining the conversation on the beach at Tagaulei is Chatib, a long balatu blade hanging, sheathed, from his belt. He points to lumber on a white tarp with the logo of the U.N. High Commissioner for Refugees. “The wood has been there more than a year,” Chatib grumbles. “It's just rotting.” During the earthquake, the survivors ran inland about a kilometer to a settlement also called Tagaulei. Halfway to the second Tagaulei, a path through bamboo rushes passes a small clearing with plots for three homes, including one for Aceh's family. All that's been built so far is the concrete base. “We are waiting for our wood,” Aceh says.

    Uncertain future.

    Ahmad Chatib lost his home and his boat to subsidence.

    CREDIT: R. STONE/SCIENCE

    Before the earthquake, Chatib was a fisher. Now, sans boat, he says he has been reduced to selling fish caught by other men. “We are very poor,” he says, before adding, bitterly, “Why are we still living like this? We feel left out and forgotten.”

    AMDA's senior logistics officer sympathizes with the Tagauleians' plight. “We feel very sorry for them. They have been waiting so long” for help, says Naoto Usami. AMDA chartered an amphibious craft last year to deliver the lumber now sitting on the beach; the nongovernmental organization didn't anticipate the difficulty of moving it inland to homesteads in Tagaulei Two. The delays have created tensions with the villagers. “Our staff have been threatened with knives,” he says. AMDA is planning a second lumber shipment for next month and aims to complete all homes by the end of January. “Now,” says Usami, “we're moving very fast.”

    Night has fallen, and Chatib says goodbye: a melodious “Ya-ahowu!”Yahowuuuuu!” yodels Suprihanto, who does not speak the local language. Others chime in with mangled variations like off-key a cappella singers; it's infectious. The skiff sets out for the return to Bozihona. Lightning flares on the horizon. But the sea is glassy calm, and glowing bioluminescent plankton stream off the bow like sparks. The breathtaking serenity is a sharp contrast to the horrors that Chatib and his fellow villagers endured last year.

    Over the coming decades, the tilted crust around Nias will settle gradually—returning to its approximate position before the 2005 quake—as strain on the fault builds to a crescendo for the next gargantuan release. But for Chatib and many other islanders, life may never regain its prequake equilibrium.

  11. GEOPHYSICS

    Facing a Tsunami With No Place to Run

    1. Richard Stone
    Backs to the wall.

    Revanche Zefrizal argues that building tsunami shelters would save more lives than Padang's new seawall.

    CREDIT: R. STONE

    PADANG, INDONESIA—It is hard to imagine a more terrible catastrophe than the 2004 tsunami that killed more than 220,000 people in southern Asia. But experts say that the next great earthquake on the Sunda trench could be at least as bad. Geologists warn that within the next 30 years, there will likely be another great Sunda megathrust rupture farther south, just off Padang, Sumatra's second largest city, where 800,000 people live. “We're getting close. Strain has been accumulating for more than 200 years,” says Richard Briggs, a geologist at the California Institute of Technology (Caltech) in Pasadena. “The outlook isn't promising.”

    Even knowing this, planners are struggling to devise an adequate evacuation plan. If the megathrust rupture occurs where it's expected, offshore of Padang, people will have a mere 20 to 30 minutes to reach a safe haven before the resulting tsunami hits. The city's diabolical geography and street grid, hard up against the volcanic Barisan Mountains and crisscrossed with rivers and swamps, make it impossible for the entire population to flee, says Revanche Zefrizal, a coordinator for the nonprofit Komunitas Siaga Tsunami (Kogami). “We have five death zones,” says Zefrizal, making a throat-slitting gesture. He and others are stumped on how to get 200,000 people near the seafront to safety in time. “We haven't overcome this challenge yet.”

    It's not for lack of trying. Zefrizal, with the Indonesian military, local police, and emergency services personnel, has been staging evacuation drills and school education campaigns district by district in the Padang region. Meanwhile, a German-Indonesian team has deployed sensors off the coast to measure sea-floor vibrations and pressure changes in the water column that could alert the mainland within tens of seconds of an oncoming tsunami. But they are still working out the kinks. “We can't wait for the technology,” which might fail in a crisis, says Harmin Rauf, head of Satkorlak PPB, Padang city's disaster-mitigation office. Therefore, he says, early recognition of a tsunami-spawning earthquake is essential.

    With that in mind, Kogami has been instructing locals to be prepared to act decisively if tremors last more than a minute and are so strong that they fell building supports and knock people off their feet. In that event, Zefrizal says, quake survivors must pick themselves up and flee on foot to high ground or take shelter in the upper floors of designated tall buildings that withstand the quake. “People wouldn't have time to go looking for mothers or their children. They have to just run,” says Rauf. He's working with the mosques to connect muezzin loudspeakers to a central radio dispatch for broadcasting warnings and instructions.

    About 400,000 of Padang's residents live on the beach or in a warren of narrow streets along the coast. Two- and three-story apartment complexes, shops, and restaurants are interspersed with striking buildings with sharply sloping roofs: “bull's horns” symbolizing the bravery and resilience of the Minang people of west Sumatra. Close to shore, not even the imposing Minang architecture could stave off a tsunami. “All these buildings would be swept away,” says Imam Suprihanto, a marine biologist who works with the Caltech team. The city has laid down boulders to form a 5-meter-high seawall, “but this will only protect Padang from a small tsunami,” Rauf says. The towering waves from a great quake would wash over them. Only a few main roads lead inland, leaving about half of the beachside residents no viable escape route.

    City officials plan to widen the main roads, says Rauf. Another idea is to build a series of concrete towers along the beach in which people stranded near shore could ride out a tsunami. One prominent advocate of this approach is Roger Bilham, a geophysicist at the University of Colorado, Boulder, and a top expert on earthquake risk in Southeast Asia. “Tsunami shelters should be constructed every 100 meters along the coast,” he says. Bilham envisions 10-meter-high “indestructible platforms” with numerous entry stairs and stocked with supplies. Zefrizal backs the idea, although at present there's a showstopper: “There's no money in the budget to make the towers,” he says. Kogami plans to go cap in hand to international nonprofits.

    Flip-flop.

    Before the 2005 rupture, Nias's southwest coast was subsiding, as indicated by the stand of dead coconut palms seaward of the beach (top). The rupture lifted the coast here 2.5 meters.

    CREDIT: KERRY SIEH

    The potential for severe subsidence would complicate tower construction and an evacuation. Just as the quake that shook southeastern Nias Island last year tilted the landscape (see main text), a Padang earthquake would be accompanied by subsidence along the coast, says Briggs.

    Modeling by Caltech's Mohamed Chlieh, based on the effects of megathrust ruptures off Padang in 1797 and 1833, predicts tectonic subsidence—a tugging down of the western Sumatran coast near Padang—of up to 50 centimeters, roughly the same as in Aceh Province, on Sumatra's northern tip, in 2004. Slumps and fissures from liquefaction of soft, sandy ground could exacerbate local flooding. Modeling by Jose Borrero of the University of Southern California in Los Angeles has shown that subsidence will abet the killing power of a tsunami, allowing water to run farther inland with more energy, threatening about 1 million people along a 500-kilometer stretch of coast. Thus tsunami shelters would have to be built to ride out a stronger wave and shifting ground.

    Psychology will also come into play. “West Sumatrans believe in science, but as Muslims, we also believe that natural disasters are God's will,” says Rauf. “We want to know how to cope with a tsunami better. But we will not be afraid of it.” Rauf can only hope that the rest of the population will be so levelheaded when the day of reckoning comes, as it surely will.

  12. AAS HIGH ENERGY ASTROPHYSICS DIVISION

    Early Look at Exploding Supernova Spotlights Deadly Stellar Tango

    1. Tom Siegfried*
    1. Tom Siegfried is a writer in Los Angeles, California.

    A lucky glimpse of x-rays emanating from a stellar explosion may be good news for the reliability of cosmologists' favorite standard candle.

    CREDIT: NASA/SWIFT/S. IMMLER

    Astrophysicists using NASA's Swift satellite have spotted the first signs of x-rays produced in the aftermath of a type 1a supernova, a cataclysmic burst of energy used to gauge cosmic distances. Because all type 1a supernova explosions are supposedly produced by a common ignition mechanism, differences in their apparent brightness can be used to compute distances to far-off galaxies in which the explosions occur. Measurements of type 1a supernovae have provided the prime evidence that the universe is expanding at an accelerating rate.

    The new results help confirm the standard picture of type 1a explosions, says Eric Schlegel of the University of Texas, San Antonio, who was not involved in the research. Cosmologists have assumed that type 1a supernovae occur in binary systems in which a white dwarf star about as massive as the sun grows by siphoning off material from a nearby companion. When the white dwarf swells to more than 1.4 times the sun's mass, it ignites in a thermonuclear explosion, blowing itself to bits.

    But there was always a chance that the presumed scenario was naïve or mistaken. The new results are the strongest observational evidence so far confirming the standard picture. “Without knowing it was a white dwarf in a binary system, there was always that nagging worry that nature was more clever than we were,” Schlegel says. “This helps eliminate that worry.”

    The findings support the white dwarf mechanism by establishing the existence of a companion, which would be necessary to provide a white dwarf with the excess matter needed to explode. The report also identifies the nature of the companion star, said Stefan Immler, the leader of the Swift team, who presented the results at the meeting. Immler, of NASA's Goddard Space Flight Center in Greenbelt, Maryland, said scientists have debated whether the companion is another white dwarf or a more massive star. The new data point to a more massive star, at least for this supernova, designated 2005ke. It was spotted last year in galaxy NGC 1371, about 65 million light-years away.

    Detection of x-rays within days after the explosion indicates that its shock wave encountered dense gas near the supernova. That material must have blown in on the stellar wind from a massive companion star. Observations of ultraviolet radiation from the explosion, about a month later, also confirm that explanation, Immler said. Only a huge star could provide enough matter to account for the radiation produced.

    Immler stresses that many more explosions will need to be observed over lengthy time periods to know for sure whether such explosions are really reliable standard candles for cosmological studies. “We're trying to get the big picture here,” he says. “We're making a concerted effort to observe as many supernovae as we can as fast as we can.”

    A paper describing the new results was published last month in Astrophysical Journal Letters.

  13. AAS HIGH ENERGY ASTROPHYSICS DIVISION

    Snapshots From The Meeting

    1. Tom Siegfried

    Galactic jet fuel. In most galaxies, including our Milky Way, a supermassive black hole sits quietly at the core. But in a small subset of galaxies, the nucleus is “active,” spewing energetic radiation. And in a still-smaller subset, some of the energy shoots into space in the form of bright beams known as jets.

    For years, astronomers have wondered about what the jets are made of. Now there is an answer, based on two active galactic nuclei observed by NASA's Swift satellite.

    Jets are known to contain electrons but are electrically neutral, so some positively charged particles—either protons or positrons—are needed to balance the electrons' negative charge. At the meeting, Rita Sambruna of NASA's Goddard Space Flight Center in Greenbelt, Maryland, reported that Swift measurements of x-rays produced in the jets indicate that they contain protons. The total amount of matter in a jet at any given time, Sambruna says, is about equivalent to the mass of Jupiter.

    Black-hole dervish. The Japanese x-ray satellite Suzaku has pinned down the spin of a massive black hole in the core of galaxy MCG-6-30-15. Previous observations hinted that the black hole is spinning rapidly. Suzaku has verified those suspicions with precise measurements of x-rays emitted by hot gas near the black hole, Andrew Fabian of the University of Cambridge, U.K., reported at the meeting. The spinning rate is on the order of one rotation every 5 minutes, Fabian says, about 90% of the physically possible maximum.

    Chris Reynolds, an astrophysicist at the University of Maryland, College Park, who was not involved in the research, says the finding is significant for confirming that some black holes spin so rapidly. As much as 30% of a black hole's energy can be stored in its rotational motion, Reynolds said, suggesting that the spin may contribute to the energy output of quasars, cosmic lighthouses believed to be powered by black holes at the core of active galaxies.

  14. HELAMAN FERGUSON PROFILE

    Carving His Own Unique Niche, in Symbols and Stone

    1. Katherine Unger*
    1. Katherine Unger is a writer in Washington, D.C.

    By refusing to choose between mathematics and art, a self-described “misfit” has found the place where parallel careers meet

    CREDIT: J. MOGLIA/SCIENCE

    BALTIMORE, MARYLAND—Helaman Ferguson's sculpture studio is set back from the road, hidden behind a construction site. Inside, pieces of art line shelves and cover tabletops. Ferguson, clad in a yellow plastic apron and a black T-shirt, serenely makes his way through the room. The 66-year-old is tall and white-haired, his bare arms revealing a strength requisite for his avocation.

    The most striking work in the studio is a more than 2-meter-tall, 5-ton chunk of granite. When it is finished, it will stand in the entry to the science building at Macalester College in St. Paul, Minnesota. Right now, it is a mass of curving surfaces sloping in different directions, its surface still jagged with the rough grains left by the diamond-toothed chainsaw Ferguson uses to carve through the stone.

    “I'm in my negative-Gaussian-curvature phase,” Ferguson says. “Say we're going to shake hands, but we don't quite touch. OK, see the space between the two hands?” That saddle-shaped void, he explains, is a perfect example of negative Gaussian curvature. Our bodies contain many others, he adds: the line between the first finger's knuckle and the wrist, for instance, and where the neck meets the shoulders.

    The topological jargon is no surprise: Ferguson spent 17 years as a mathematics professor at Brigham Young University (BYU) in Provo, Utah. What is unusual is how successfully he has pursued a dual career as mathematician and artist and the ease with which he blurs the categories. Math inspires and figures in almost all of Ferguson's artistic works. Through them, he has helped some mathematicians appreciate the artist's craft and aesthetic. And he's persuaded perhaps even more artists that math may not be as frighteningly elusive as they believe, or even if it is out of their reach, it's as beautiful as any work of art they might imagine. “The way he has brought together the worlds of science and the arts—this is an admirable thing,” says Harvey Bricker, Ferguson's former college roommate.

    Twin callings

    Ferguson himself finds it hard to say which calling came first. As a teenager in upstate New York, he learned stone carving as an informal apprentice to his adopted father, a stonemason. Artistically, however, he was more drawn to painting. After finishing high school in 1958, he wanted to study art as well as math. He chose Hamilton College, a liberal arts school in upstate New York near where he had spent most of his childhood, where he could do both.

    After getting his math degree, he enrolled in a doctoral program in math at the University of Wisconsin, Madison. He paid for some of his living expenses by selling paintings. He also met and began dating an undergraduate art student, Claire. The couple married in 1963 and had their first child (of an eventual seven) in 1964. Ferguson dropped out of school for a couple of years to work as a computer programmer, then resumed his math studies. He obtained his master's degree in mathematics at BYU and a doctorate in group representations—a broad area of math that involves algebra, geometry, topology, and analysis—at the University of Washington, Seattle. In 1971, he accepted an appointment as assistant professor at BYU.

    As a mathematician, Ferguson is perhaps best known for the algorithm he developed with BYU colleague Rodney Forcade. The algorithm, called PSLQ, finds mathematical relations among seemingly unrelated real numbers. Among many other applications, PSLQ provided an efficient way of computing isolated digits within pi and blazed a path for modeling hard-to-calculate particle interactions in quantum physics. In 2000, the journal Computing in Science and Engineering named it one of the top 10 algorithms of the 20th century.

    Meanwhile, Ferguson's artistic career also developed apace. When he married Claire, a painter, the two struck a deal: “I get the floors, she gets the walls,” he says. He began focusing more on sculpture. The art department at BYU allotted him some studio space, and he turned out a regular stream of work. He's done commissions for the Maryland Science and Technology Center, the University of California, Berkeley, the University of By refusing to choose between mathematics and art, a self-described “misfit” has found the place where parallel careers meet St. Thomas in St. Paul, and many other institutions. He has also designed small sculptures for awards presented by the Clay Mathematics Institute in Cambridge, Massachusetts, the Canadian Mathematical Society in Ontario, and the Association for Computing Machinery in New York City.

    Function-al form.

    The Fibonacci Fountain at the Maryland Science and Technology Center was inspired by the “golden ratio.”

    CREDIT: J. MOGLIA/SCIENCE

    He has worked to keep a foot in each of the “two cultures.” While at BYU, he taught a course each year for honors students called Qualitative Mathematics and Its Aesthetics. Both art students and math students enrolled: the artists looking for a palatable way to take in a math requirement, and the math students lured by the promise of higher level mathematics. Ferguson delivered on both ends. He taught concepts mathematicians don't normally encounter until graduate school, such as braid theory. Artists could relate to braids as physical objects, rope or hair that can be woven into a specific form. But students were also asked to write down an algebra to go along with how the braid was formed—a noncommutative algebra.

    “Some of these folks were in there because they were either afraid of or hated math,” says Ferguson. At the end of the semester, however, “quite a few art students wanted a follow-on semester—more math, more art.”

    Bridging

    Ferguson, who left BYU in 1988, now devotes most of his time to his art. For his large-scale or complicated pieces, he uses computer programs such as Mathematica to form and refine the shape he wants the finished piece to take. “With sculpture, you want a piece to be a unit so it has direct impact as a form,” he says. “Sculptures are complicated enough already.” With computer programs, he says, before even putting hand to stone “you can walk around [the piece] and see a different view; you can touch it and reshape it to make it simpler and more direct.”

    Once the design is in place, Ferguson turns to the task of carving the stone. He works alone, without assistants, using both chisels and assorted power tools. Finally comes a lengthy smoothing process, going from 20-grit sandpaper to as fine as 8500-grit. Ferguson has to work “wet” much of the time, using water to wash down the fine particles of stone that could otherwise become deposited in his lungs. For some of the work, he dons gloves made of woven stainless steel and a positive-pressure facemask. A large sculpture can take several months to complete, working flat-out.

    Granite is Ferguson's favorite medium. “Mathematics is kind of timeless,” he says, “so incorporating mathematical themes and ideas into geologically old stone—that's something that has great aesthetic appeal to me.” He also likes the idea that his sculptures will be around for millions or even billions of years.

    Tough medium.

    A diamond-toothed chainsaw helps Ferguson carve through granite rocks that are up to a billion years old.

    CREDIT: J. MOGLIA/SCIENCE

    The finished sculptures vary widely in appearance. Some are delicate, with looped projections or intricate imprints, and are small enough to hold in one's hand. Others are massive, meant to be touched, even climbed on (as many children have discovered). As a rule, they also contain much more detail than meets the eye. “My work generally involves a circle of ideas,” says Ferguson. People he interacts with, new information he obtains, mathematics he has had on his mind—all of these become “part of the design consideration.”

    Twisted.

    Braids and knots turn up in many of Ferguson's works, including these small metal sculptures

    CREDIT: J. MOGLIA/SCIENCE

    As an example, he cites an architectural-scale sculpture recently installed outside his alma mater Hamilton College's new science building. The work, made of 10-centimeter-thick granite, centers on a pair of massive disks representing the planets Mars and Venus. “Venus” is exactly 161 centimeters in diameter—the height of the average female Hamilton student, taken from the records of one of the college's psychology professors. “Mars” is 174 centimeters in diameter—the average male student's height. The disks are inlaid with tiles in a pattern defined by the Poincaré and Beltrami-Klein models of plane hyperbolic geometry.

    Ferguson's admirers say his artwork goes far beyond academic exercises. David Broadhurst, a physicist at the Open University in Milton Keynes, U.K., learned about Ferguson's sculpture after using the PSLQ algorithm in his research in quantum mechanics. He compares Ferguson's artistic renderings of math to Fournier playing the Bach cello suites, “giving expression to abstract forms, whose beauty is preexistent to the interpretation, yet recreated in a widely accessible medium.”

    For his part, Ferguson says his lifelong project to embody mathematics in mass and form is very much in the spirit of the times—and he credits technology with making it all possible. “We're living in the golden age of art, we really are. But it's also the golden age of science,” he says. “Today, young people have seen more art and science in, say, their first 25 years of life than anyone in the years before that.” With the collaborations between computer scientists and artists, and tools for art being used as tools for scientific exploration and invention, Ferguson suggests we may be in the midst of a second Renaissance. “It's a great time to be alive,” says Ferguson, “because there are more places for misfits like myself to survive.”

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