News this Week

Science  20 Jul 2007:
Vol. 317, Issue 5836, pp. 304

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    Nuclear Weapons Milestone Triggers U.S. Policy Debate

    1. Eli Kintisch

    As with high school sweethearts reconnecting at a 25th reunion, U.S. nuclear weapons scientists have found that recapturing the magic of the past takes the right kind of people, a willingness to adapt, and a large capacity for delayed gratification.

    In a classified ceremony early this month at Los Alamos National Laboratory (LANL) in New Mexico, Department of Energy (DOE) officials celebrated the belated completion of the plutonium trigger of a nuclear bomb operationally identical to ones last built 18 years ago. The star of the ceremony was the so-called pit—a layered piece of metal the approximate size and shape of a Fabergé egg, with a hollow core—that DOE certified as ready for the nuclear stockpile. The occasion was a milestone for the nuclear weapons program and paves the way for more ambitious work, including building entire weapons from scratch without conducting nuclear tests. It also opens the door for LANL, traditionally a research lab, to consider expanding into manufacturing.

    Critics of U.S. nuclear policy, however, say that building new pits contradicts the country's stated intention to reduce its nuclear arsenal. They also believe that the $1.4 billion spent on the project shows that the cost of manufacturing weapons parts, in the words of activist Greg Mello of the Los Alamos Study Group in Albuquerque, New Mexico, could be “toxic to science” by diverting funds from research.

    In 1989, the government found environmental and other violations at the nation's only source of building plutonium pits, a DOE facility at Rocky Flats, Colorado. It was later shut down, halting work on a batch of pits for the W88, a 475-kiloton submarine-fired warhead. In 1996, the government asked LANL to build a set of replacements within 5 years, with one caveat: A 1993 ban on nuclear tests meant that the scientists wouldn't be able to test their version.

    That restriction stiffened the already-imposing technical challenges of matching the Rocky Flats specifications. The relatively small plutonium research facility at Los Alamos had the requisite ventilation and glove boxes, for example, but its foundation would not support the heavy-duty plutonium forming tools used at Rocky Flats. Instead, workers had to pour molten plutonium into shaped molds and weld pieces together. To conform to new environmental rules, engineers cut down on the use of lubricants and used new solvents to clean metal surfaces.

    Even so, in 2001, DOE auditors concluded that the program was “at risk.” They cited delays in half of the roughly 40 nuclear manufacturing procedures to be finalized. “Everyone underestimated how hard it was going to be,” says former DOE official Madelyn Creedon, now a Senate aide.

    Boxed in.

    Los Alamos scientists worked extensively with glove boxes to develop a new plutonium trigger.


    In response, then-lab director John Browne replaced the head of the program with co-leaders, one overseeing physics and the other, weapons manufacturing and engineering. In addition, says Richard Mah, a former Rocky Flats metallurgist who led the revamped manufacturing effort from 2001 to 2004, the lab brought in “some old hands who had done some of this stuff.” By 2003, researchers had matched the physical specifications of the Rocky Flats design.

    The parallel management structure helped the lab verify that the new pit would work, says Mah. For example, fears that a different metallic grain size could hamper performance dissolved after verification experiments—which included non-nuclear explosions, numerical simulations, and materials science studies—showed physicists that the difference wouldn't degrade pit performance. It took until this year for LANL to certify the pit as stockpile-ready, meeting a goal set in 2001.

    Although the Rocky Flats pits had been proven to work in underground tests, LANL researchers realized they weren't perfect. Layered metal surrounds their hollow plutonium shell, which undergoes fission when crushed by conventional explosives. Studies at Los Alamos found that the original pits contained “impurities that can affect mechanical properties,” says DOE weapons official David Crandall. At first, “there was an attempt to make plutonium in pits as pure as possible,” he says. But weapons scientists made more credible progress when they decided the pits “needed to be as much as possible like those [previously] tested, including any impurities in plutonium.”

    Crandall says the new W88 pits show that the country's nuclear weapons complex can both monitor current bombs and build new ones without testing them: “This was a valuable initiation into the processes we'll need for RRW [the Reliable Replacement Warhead].” The RRW program seeks to build new bombs from scratch to replace aging warheads (Science, 9 March, p. 1348). Planetary geophysicist Ray Jeanloz of the University of California, Berkeley, says that the struggle to make the new pits highlights the importance of maintaining a well-funded and experienced talent pool that can respond quickly to emergencies or new developments.

    Senator Pete Domenici (R-NM), speaking at the 2 July celebration, used the milestone to attack some $600 million in cuts to the weapons program by House appropriators in DOE's upcoming 2008 budget, several of which would affect planned expansion of plutonium science at Los Alamos. The fate of the cuts is uncertain, however, given different versions of the spending bill that must be reconciled and a White House threat to veto the overall bill.

    In the meantime, Mah, who last year worked directly for the new Bechtel-University of California lab management partnership, says that building more pits could become an additional business for the lab. His fear is that government officials might value manufacturing more highly than science. But a lab spokesperson says “there's no plan to make [manufacturing] the primary role of Los Alamos.”


    Singapore Firm Abandons Plans for Stem Cell Therapies

    1. Dennis Normile

    In a sign that hopes for quick medical benefits from stem cells are fading, ES Cell International (ESI)—a company established with fanfare in Singapore 7 years ago—is halting work on human embryonic stem (hES) cell therapies. Investors lost interest because “the likelihood of having products in the clinic in the short term was vanishingly small,” says Alan Colman, a stem cell pioneer who until last month was ESI's chief executive.

    ESI's setback may dampen investors' enthusiasm for stem cell therapies, says Robert Lanza, vice president for R&D at Advanced Cell Technology in Worcester, Massachusetts: “What the field badly needs is one or two success stories.”

    Colman, a member of the team that cloned the sheep Dolly, will become head of the Singapore Stem Cell Consortium, which funds research at institutes affiliated with Singapore's Agency for Science, Technology and Research (A*STAR) and also offers grants. He will also set up a lab at A*STAR's Institute of Molecular and Cell Biology. Most of the 24 scientists working on hES cell therapies at ESI will continue their research with “more secure government funding” at A*STAR's new Institute of Medical Biology, Colman says. A*STAR announced Colman's move on 9 July.

    ESI was set up in 2000 to commercialize hES cell findings produced by a collaboration involving Monash University in Clayton, Australia; National University of Singapore; Hadassah Medical Organization in Jerusalem; and the Hubrecht Laboratory in Utrecht, Netherlands. Australian investors and an investment arm of Singapore's government put up seed funding, and ESI had raised $24 million as of last October, according to the company. ESI hired Colman as chief scientist in April 2002; he became CEO in 2005.

    From bedside to bench.

    Sagging investor confidence in stem cells has prompted Alan Colman to leave the corporate world for a basic research lab.


    The company was attempting to turn hES cells into insulin-producing cells to treat diabetes and cardiac muscle cells to counter congestive heart failure. Both conditions represent major markets with unmet clinical needs, but making well-functioning insulin-producing cells “proved really difficult,” Colman says. Both envisioned therapies would need at least a billion cells for each human dose. Producing such numbers at the required purity “becomes very expensive,” Colman says, and meeting these challenges would have taken longer than investors have patience for.

    ESI's setback need not cast a pall on the field, researchers say. Alan Trounson, a Monash University stem cell scientist who contributed to the research ESI was trying to take to market, says he is “profoundly disappointed” that the company is giving up. But he says that ESI pursued “a high-risk strategy” in focusing narrowly on two potential applications. With the field still young, Trounson says, “the primary aim should be to establish a broad platform of robust and reliable science that can under pin translation to clinical applications.”

    Irving Weissman, a stem cell researcher at Stanford University in Palo Alto, California, agrees: “ES cell research is, for the most part, still scientific discovery research.”

    Although ESI is out of the game, at least two companies say they have hES cell therapies in the pipeline. Geron Corporation in Menlo Park, California, expects to start clinical trials of a therapy for spinal cord injury early in 2008, according to spokesperson David Schull. And by early next year, Advanced Cell Technology hopes to file a new drug application for a treatment for macular degeneration, Lanza says.

    ESI, under new leadership, will now focus on providing hES cells and derived cells for basic research and drug development, Colman says. He admits to a “tinge of disappointment that the field is moving more slowly than I had hoped.” Colman hopes to spur the field along with his own research, although he declines to discuss details.


    Conservationists and Fishers Face Off Over Hawaii's Marine Riches

    1. Christopher Pala*
    1. Christopher Pala is a writer based in Honolulu.

    HANAUMA BAY, HAWAII—The school of big-eye jacks was right where Alan Friedlander of the National Oceanic and Atmospheric Administration's biogeography branch said it would be, circling slowly at the mouth of Hanauma Bay, a protected area just 15 kilometers from the skyscrapers of downtown Honolulu. There must have been close to 200 fish, each about 50 centimeters long and utterly unafraid as Friedlander, a marine biologist, glided through them.

    “You hardly ever see this anymore in Hawaii,” Friedlander said after surfacing. Jacks are prized by anglers, and such large schools have become rare in inhabited parts of the archipelago, he says.

    Friedlander knows the bay better than most. He published a study in the April issue of Ecological Applications showing that total fish biomass in Hanauma and 11 other protected areas was 2.7 times greater than the biomass in comparable unprotected areas. And in the uninhabited 2000-kilometer-long Northwestern Hawaiian Islands chain, a national monument since 2006, there is 6.7 times more fish biomass on average than in comparable habitats—an indication that humans have reduced fish stocks in the main Hawaiian islands to about 15% of what they once were.

    Recipe for recovery.

    Rebuilding fish stocks will require putting at least a fifth of Hawaii's waters under protection like Hanauma Bay, says Alan Friedlander.


    To Friedlander, the message is simple: The main Hawaiian Islands' reserves, which protect only 0.3% of the coastline, are too small. “If you want to rebuild fish stocks, you need to stop fishing in at least 20% of Hawaii's waters and regulate fishing in the rest,” Friedlander says. Increasing the protected areas, therefore, would result in a larger fish catch.

    The appeal for new conservation areas prompted a reaction. In March, the state's House of Representatives approved a “right-to-fish” bill that would require the state to provide unattainable data, such as stock assessments throughout species' entire ranges, before any new protected area is created. The bill “would tie up all fishing regulations, not just marine reserves, in endless studies and red tape, making it impossible for the state to properly manage the public's marine assets,” says William Chandler, director of ocean policy at the Marine Conservation Biology Institute in Bellevue, Washington. To his relief, Hawaii's Senate significantly modified the bill. But scientists and state officials expect the fight to continue in the next legislative session, which starts in January.

    Although similar right-to-fish bills have been approved in Rhode Island and Maryland, they have not impeded the creation of protected areas in those states, says Sarah Clark Stuart of the Coastal Ocean Coalition in Atlantic Highlands, New Jersey. Because the Hawaii legislation would effectively end all fishing restrictions, she says it “is far more anticonservation than any of the other bills that were introduced in the U.S.”

    Hawaii's right-to-fish bill got further than a conservation bill in the House. In 2003, Friedlander helped draft legislation that would have set aside 20% of state waters for conservation. Like other states, Hawaii controls the first 3 nautical miles (6 kilometers) off its coasts, and the federal government controls the rest, up to 200 miles (370 kilometers). The Marine Reserve Network Act would have made Hawaii the leader in marine conservation in the United States, where less than 1% of coastal waters are protected. But the bill drew the ire of Hawaii's fishing lobby and was scuttled.

    The loss, conservationists say, is a cautionary tale of how science sometimes is no match for a powerful bureaucracy tied to fishing interests.

    As Hawaii's tourism grew, and cost of living skyrocketed—the state has the nation's highest average rents—fishing became an important supplement for poorer residents. The use of gillnets, which snare turtles, seals, and nonfood fish in addition to target species, is widespread. Trolling, shore casting, and spearfishing are unregulated, and the state's estimated 260,000 anglers are not licensed. Only this year were restrictions put on gillnets, including a ban on their use on Maui Island and overnight elsewhere.

    Opponents of the Marine Reserve Network Act gained momemtum earlier this year in a series of meetings designed to increase input from native Hawaiian communities. The meetings were organized by the Western Pacific Regional Fishery Management Council (Wespac), one of eight such regional councils that advise the U.S. Commerce Department. Wespac's chair is Sean Martin, president of the Hawaii Longliners Association. State officials and environmentalists have long accused Wespac of defending narrow fishing industry interests.

    Wespac's influence is supposed to be limited to federal waters, but activists and state officials contend that the organization lobbied illegally for the right-to-fish bill. “Numerous times during the process that produced the bill, I saw Wespac employees openly talking to legislators about it,” asserts Keiko Bonk of the Northwest Hawaiian Islands Network, which campaigns for marine conservation. The bill passed the House, but a Senate draft now awaiting action would encourage community-led protection efforts.

    In May, Bonk filed a complaint with the Commerce Department's Inspector General, claiming that Wespac had violated statutes that prohibit federal employees from lobbying state legislatures. Bonk called for an investigation and congressional hearings. Wespac denies it engaged in lobbying. The right-to-fish bill “has nothing to do with us,” says Paul Dalzell, Wespac's senior scientist, adding, “All I know is that it was drafted by fishermen.”

    “The scary thing is that the bill could pass next year,” says Peter Young, who recently completed a term as director of Hawaii's Department of Land and Natural Resources, which manages the state's waters.

    “If it passes,” adds William Aila, an active Hawaiian fisher and harbormaster, “it's going to further deplete our marine resources. That's unacceptable for our future generations.”


    Did a Megaflood Slice Off Britain?

    1. Richard A. Kerr

    Britain as an ungainly peninsula of France? It might have been. At some time in the geologic past, it almost certainly was. But long ago, some force somehow lowered a high-standing ridge from Dover to France that would be dry land today. A group of geoscientists has new evidence of the culprit: A huge gushing of lake water, they suggest, cut down into solid rock to form the Dover Strait before rushing down the then-dry English Channel.

    The strait-cutting megaflood, if it happened, would not have been the first or the last of its kind. The classic example broke out of ancient Lake Missoula about 15,000 years ago to ravage eastern Washington state and create the tortured terrain of the Channeled Scablands. That required a flow of 10 million to 20 million cubic meters of the lake's glacial meltwater each second, or 50 to 100 times the flow of the Amazon River.

    Geologist Sanjeev Gupta of Imperial College London and his colleagues present evidence in this week's issue of Nature for scablandlike terrain downstream of the Dover Strait. Gupta and colleagues had to look for their evidence at the bottom of the English Channel, which melting ice sheets filled with water at the end of the last ice age. Using depth-finder data collected for navigational charting, they mapped the bottom in new detail. They found kilometer-scale, flat-topped islands in the same distinctive elongated shapes as the erosional remnants of the Channeled Scablands. They also saw broadly sweeping streamlined valley edges, “braided” channels, ridges and grooves pointing downstream, and crescentlike scours. All these features speak of extreme flows, the group says.

    Gupta and his colleagues envision a lake hemmed in by glacial ice where the southern North Sea is today. The lake's waters could have overtopped the Dover ridge a few hundred thousand years ago, lowering the ridge and increasing the flow until 200,000 to 1 million cubic meters per second were streaming over the ridge. The megaflood would have cut loose the peninsula during times of high sea level like the present, the group suggests. Island Britain would have been born.

    A day's work?

    The elongated “islands” and streamlined edge of this submarine valley on the floor of the English Channel suggest that a huge but brief flood gushed between Britain and France.


    “When you put the association of landforms together, it is very similar to what Victor Baker has described in the Scablands,” says geologist Philip Gibbard of the University of Cambridge. “I'm persuaded by it.” But Baker, of the University of Arizona in Tucson, says “it's not a smoking gun, but this is a very productive idea that deserves more attention.”


    Program Proves That Checkers, Perfectly Played, Is a No-Win Situation

    1. Adrian Cho

    If two players face off at checkers and neither makes a wrong move, then the game will inevitably end in a draw. That's the result of a proof executed by hundreds of computers over nearly 2 decades and reported online by Science this week ( The finding guarantees that an appropriately programmed machine will never lose to a human. It also marks a personal victory for Jonathan Schaeffer, a computer scientist at the University of Alberta in Edmonton, Canada, who set out to “solve” checkers in 1989.

    “It's a huge accomplishment,” says David Levy, president of the International Computer Games Association in London and an expert on chess-playing machines. “It's by far the most complex game ever solved.” The tools and strategies developed for the problem might prove useful for analyzing genetic code or computerized translation, he says.

    The point of checkers, or draughts as the game is also known, is to get the jump on your opponent. The game is played on an eight-by-eight grid of red and black squares. The checkers are black and red disks that can slide forward diagonally from black square to black square. The players, call them Bob and Rita, start with 12 checkers each in the rows closest to their sides of the board. Players move in turn, and Bob can capture one of Rita's checkers by hopping over it into an empty space just beyond, and vice versa. Checkers that cross the board become “kings” that can move backward. The game continues until one player captures all of the other's pieces.


    Unable to beat the computer program, a human will eventually make a mistake that leads to a win for the machine.


    Schaeffer and his team have shown that if Bob and Rita have perfect foresight, they will always reach a stalemate in which neither can finish the other off. So checkers resembles tick-tack-toe (known as “noughts and crosses” in Britain), the game in which players fill a three-by-three grid with X's and O's in hopes of getting three in a row. Given that there are roughly 500 billion billion possible arrangements of checkers on the board, proving checkers is a guaranteed draw is far harder than proving that tick-tack-toe can't be won.

    The researchers began by constructing a database of all 39,000 billion arrangements with 10 or fewer pieces on the board. In the process, they determined whether each one led to a win for black, a win for red, or a draw. They then considered the very beginning of the game, opened with a move by black, and then used a specialized search algorithm to trace out subsequent moves and show that, as the two players try to maximize their advantage, they inevitably steer the game to one of the 10-checker configurations that leads to a draw.

    Schaeffer credits improvements in computers for making the result possible. In fact, he suspended work from 1997 to 2001 to wait for a particular technology—the 64-bit processor—to mature. But Murray Campbell, a computer scientist at IBM's Thomas J. Watson Research Center in Hawthorne, New York, says that the researchers' ingenuity was key, too. “Without a lot of the clever ideas behind what they did, I think it would have been a number of years before technology alone could have solved checkers,” says Campbell, who co-wrote the Deep Blue program that defeated chess champion Garry Kasparov in 1997.

    Most experts expected that checkers would eventually be proved a draw, says Jaap van den Herik, a computer scientist at Maastricht University in the Netherlands, if only because grandmaster players routinely play each other to a draw. But, he says, “if you have not proved the result, then every expectation is worth nothing.”

    Schaeffer says he feels vindicated by the proof. In 1994, a program he developed called Chinook played the then-reigning world champion, Marion Tinsley, to a series of draws before Tinsley withdrew because of health problems and conceded. Tinsley, who is considered the best player ever and who lost only three tournament games from 1951 to 1991, died of cancer 8 months later. Some players scorned Schaeffer, he says, and even charged that the stress of the special title match had killed Tinsley. Chinook defended its crown in two subsequent matches against the next-highest-ranked player. “To this day, I still get people saying that you would never have beaten Tinsley,” Schaeffer says. “The program today would never lose to Tinsley or anyone else, period.” And because humans eventually make mistakes, the program should inevitably prevail in a series of games against any person, even Tinsley, for whom Schaeffer says he has “great respect.”

    Van den Herik worries that Schaeffer's solution will accelerate the decades-long decline of tournament checkers. Meanwhile, Schaeffer is turning his computers to poker. In principle, that game can't be solved—but it can make you a lot of money.


    Pentagon Is Looking for a Few Good Scientists

    1. Yudhijit Bhattacharjee

    Topflight researchers at U.S. universities, the nation needs you.

    This fall, the U.S. Department of Defense (DOD) will launch a grants program to fund researchers with innovative ideas for tackling important security challenges. It will be modeled on the National Institutes of Health Director's Pioneer Awards, which support blue-sky, interdisciplinary research in biomedicine. DOD plans to make about 10 awards, each good for $3 million over 5 years. Applicants for the National Security Science and Engineering Faculty Fellowships must be U.S. citizens, and preference will be given to early-career researchers.

    Agency officials hope the program will foster research outside the bounds of predetermined research questions. “We do not have specific areas in mind; rather, we have challenges that cut across several disciplines,” says William Rees, DOD's deputy under secretary of defense for laboratories and basic science. Although the research performed under the program would be unclassified, awardees would need a security clearance to be briefed on the challenges they are supposed to address.

    The challenges, not yet chosen, are likely to be similar to those identified last year by DOD's Quadrennial Defense Review. Its list of priorities includes biometrics; social, cultural, and behavioral modeling; tracking of enemy targets; countering improvised explosive devices; and extracting information about suspicious activities and events from large data sets. Agency officials plan to invite about 20 applicants who survive an initial cut to make presentations at the Pentagon. The first class of winners will be announced next spring.

    V. S. Subrahmanian, a computer scientist at the University of Maryland, College Park, whose research is partly funded by DOD, says allowing researchers to come up with proposals in response to agency-designated challenges is an “outstanding” idea. “We are used to having research topics defined top-down by DOD,” says Subrahmanian, who plans to apply. “While that usually works well, researchers know best what their field has to offer.” He also thinks the fellowships will create a “corps of academic researchers dedicated to defense and national security.”

    If the first round goes well, DOD officials hope to eventually support as many as 50 researchers.


    Satellite Kicks Up a Storm Looking Out for Hurricanes

    1. Eli Kintisch

    An 8-year-old NASA weather satellite sits improbably at the center of the latest scientific storm raging in Washington, D.C.

    In the last 2 weeks, two congressional panels have held hearings on events surrounding the ouster of William Proenza as director of the National Hurricane Center (NHC) on 9 July. Proenza had repeatedly criticized his employer, the National Oceanic and Atmospheric Administration (NOAA), for failing to plan for the impending failure of QuikSCAT, a satellite launched in 1999 and 3 years past its design life. Proenza, a 35-year NOAA forecaster who became NHC head in January, says loss of the craft's sensors could degrade 3-day hurricane track forecasts by 16%, citing a study in press that analyzed forecasts for six 2003 storms. Scientists familiar with QuikSCAT's capabilities say Proenza was both “right and wrong” in his acerbic charges.

    To predict coming hurricanes, forecasters rely most heavily on radar or visual cloud data from satellites, typically NOAA's Geostationary Operational Environmental Satellite. Its information is bolstered by a network of buoys, hurricane-hunting planes, and coastal radar units to help modelers make computer simulations of developing storms. QuikSCAT added to that ensemble by bouncing microwave signals off ocean waters over a 1800-kilometer swath, reporting surface wind speeds by analyzing the reflections. By following a polar orbit, QuikSCAT covers 90% of the oceans, in many areas twice a day.

    NOAA researchers have lauded its data, which is particularly useful for detecting tropical Atlantic storms early and providing vital coverage over colder waters, including the Pacific. A Hawaii-based U.S. Navy official said last year it plays a “critical role” in Pacific forecasting. NHC forecasters most treasure the craft's ability to see developing tropical depressions long before they're otherwise detected. Last year, NOAA forecaster Hugh Cobb called QuikSCAT, now operating on its backup transmitter, “our bread and butter.”

    It's a breeze.

    NASA's QuikSCAT satellite measures global ocean surface winds, including speed and direction (inset).


    But forecasters don't live on bread alone. Last week, at a Senate hearing in which NOAA officials were lambasted for not preparing adequately for QuikSCAT's demise, NOAA satellite branch chief Mary Ellen Kicza tried to poke holes in Proenza's arguments. The satellite's sensors don't quantify hurricane wind speeds greater than 105 km, can't see well through rain, and its polar orbit means QuikSCAT “may not be at the right place at the right time,” she said. European and U.S. Navy satellites provide data “not quite as good” as QuikSCAT but could plug holes if the NASA craft fails, she said, adding that NOAA's other tools pick up storms once they seem headed for a landfall. “We are not blind” if QuikSCAT dies, Kicza asserted.

    Meteorologist and respected weather blogger Jeff Masters agrees, noting that the unpublished study Proenza cited involved only one of roughly seven active forecasting models. Folding in all the simulations, plus the rest of the data sources, creates a “global system” of which QuikSCAT is but one element, says hurricane expert Greg Holland of the National Center for Atmospheric Research in Boulder, Colorado. So Proenza “was right and wrong,” Holland explains.

    A joint NASA-NOAA study, due next year, will spell out the next options. But lawmakers want to push NOAA along. In May, Representative Ron Klein (D-FL) and co-sponsors proposed a bill to authorize $375 million to build a QuikSCAT replacement. “The loss of this data—whether minute or significant—could cause dire consequences,” Klein told the committee. Those funds, however, have not been included in appropriations bills moving through Congress that otherwise provide generous increases to NOAA's 2008 budget.


    Welcome to Ethiopia's Fly Factory

    1. Martin Enserink

    One of the poorest countries in the world has an ambitious plan to eliminate the tsetse fly. But some scientists say it's a waste of money

    Fly belt.

    An area of about 10 million square kilometers—including one-fifth of Ethiopia—is home to dozens of species of tsetse flies.


    KALITI, ETHIOPIA—Noisy, multicolored trucks lumber along the busy main road in this far suburb of Addis Abeba, belching clouds of smoke and honking at the pedestrians that crowd the road. A muddy, bumpy side road leads past a row of shacks to an industrial area that's home to a factory for pots and pans. Then a gate slides open, and a brand-new gray building the size of a soccer field emerges, surrounded by a sea of smooth asphalt. It's almost too clean and organized for its chaotic surroundings.

    In a matter of months, the vast building will be buzzing with activity—literally. Here, Ethiopia is developing a sophisticated weapon against an age-old scourge: the tsetse fly, which transmits a parasitic livestock disease called nagana that has long crippled the country's rural economy.

    The scheme sounds simple. Produce as many as a million male flies a week, make them sterile by blasting them with radiation for a couple of seconds, then release them in tsetse-infested areas, making sure they outnumber wild males 10 to 1. Hapless females will mate with the lab critters, but their rendezvous will produce no offspring. Repeat the procedure several times, and the tsetse population will die out.

    It's an elegant and environmentally friendly method; birth control for insects, some call it. The sterile insect technique (SIT), as it's officially known, has a long and solid track record (see sidebar, p. 312). Over the course of 50 years, it helped sweep the screwworm fly, which feeds on open wounds in livestock, from half the Western Hemisphere, and it's being used to protect everything from Chilean apples to Dutch onions to Japanese melons from voracious pests.

    Perhaps more important, it helped wipe out the entire tsetse fly population on Zanzibar's main island in the 1990s, a project hailed as an important proof of principle. Now, Ethiopia hopes it can become a model itself by showing that the same is possible on the African mainland. More than 35 countries have tsetse, and in many, they transmit not just nagana but also sleeping sickness, a devastating human disease.

    And yet, the Ethiopian project is at the center of a divisive, often caustic, debate among entomologists. Critics believe that for a variety of reasons—such as the fact that there are five tsetse species in Ethiopia—it is likely to fail. And besides, it's not a sustainable solution, they say, because flies may reinfest the country. The money—Ethiopia's government spent $12 million on the factory alone—would have been much better spent on cheaper and simpler ways to fight tsetse, such as insecticide spraying, says Glyn Vale, a former head of tsetse research in Zimbabwe. “I hate to see a poor country waste so much money,” Vale adds.

    Veterinary entomologist Ian Maudlin of the University of Edinburgh, U.K., calls SIT Ethiopia's “man-on-the-moon project.”

    These critics blast the International Atomic Energy Agency (IAEA), which is supporting the project, for seducing Ethiopia into trying sterile insects—and they're even more dismayed that other African countries are following suit. Best known for its wrangling with aspiring nuclear powers, the U.N. agency, headquartered in Vienna, Austria, also promotes the peaceful use of atomic energy, including the creation of sterile insects, and its lab in Seibersdorf, outside Vienna, is the world's premier SIT research center.

    Green Desert

    Opinions differ about the solution but not about the problem. Almost a quarter-million square kilometers of mostly fertile valley land in western and southwestern Ethiopia is infested with tsetse flies. Nagana, caused by a unicellular parasite of the Trypanosoma genus, makes keeping livestock difficult. That means fewer animals to plow the land, less milk, and less manure—in short, poverty. A large swath of Africa has the same problem. The U.N.'s Food and Agriculture Organization puts the bill for missed farming revenues in this “Green Desert” across Africa at about $4.5 billion annually.

    Then there's the human cost: Sleeping sickness, or human trypanosomiasis, is believed to infect some 50,000 to 70,000 people a year, although hard data are not available. No vaccine exists, and drugs—most more than 50 years old—are toxic and decreasingly effective. Melarsoprol, an arsenic-based drug, kills between 3% and 10% of patients.

    For colonial powers, tsetse posed a formidable barrier to the development of their African assets, and they all started programs to deal with the problem. They did have some early successes. Most famously, the Portuguese rid the small West African island of Principe of tsetse in 1905, largely by equipping plantation workers with sticky backpacks.

    Colonial concerns also inspired one of the earliest but least known studies of SIT. In the 1940s, in what was then Tanganyika and is now Tanzania, British entomologist F. L. Vanderplank discovered that crossing two different species of tsetse flies resulted in hybrids with very low fertility. This gave him the idea for a trial in which the pupae of one tsetse species were collected and transported by train to an area occupied by another species, in hope of creating sterile offspring. Vanderplank never published the results, but before his death he gave the raw data to entomologist Chris Curtis of the London School of Hygiene and Tropical Medicine, who published them in a 2005 book. The trial was a success.

    But SIT didn't really take off until after the successful U.S. fight in the 1950s against the screwworm, which was subsequently rolled back all the way down to Panama. As it turned out, it wasn't hybridization but radiation that proved the most effective way to create sterile insects.

    So far, the majority of SIT programs have addressed agricultural pests in richer countries. The projects can cost tens of millions of dollars, but those costs are often quickly recovered. The screwworm eradication, for instance, saves U.S. livestock producers $900 million a year, according to the U.S. Department of Agriculture.

    Source of pride.

    Project coordinator Temesgen Alemu (right) and insect facility manager Solomon Mekonnen—posing with a gamma ray source used to sterilize flies—hope Ethiopia's tsetse fight will serve as an example for Africa.


    Yet by the 1970s, IAEA had also set its sights on tsetse. The Seibersdorf lab refined the technology of rearing tsetse flies. Whereas at first they were fed on live rabbits and guinea pigs, cow blood is used today.

    In the mid-1980s, the agency and the Tanzanian government picked Unguja, the main island of Zanzibar, for a test site. It took almost 10 years to build a fly-rearing facility and train local staff, says Andrew Parker, a tsetse expert at IAEA. After the flies had first been attacked using insecticides, planes started delivering weekly loads of male flies across the island in August 1994. By 1997, Zanzibar was declared tsetse-free, at an estimated total cost of $5.7 million. It still is today.

    The example piqued the interest of the Ethiopian government, says Temesgen Alemu of the Southern Tsetse Eradication Project, a program of the Ethiopian Science and Technology Organization that IAEA supports with scientific expertise and technical advice. And 10 years later, thanks in part to funding from the U.N., the African Development Bank, and the government of Japan, things are well under way. Workers are busy unloading new racks and installing an automated feeding system in sparkling clean rearing halls. An old building on the same grounds now houses a colony of about 100,000 breeding females that produce a weekly harvest of 10,000 males. In the new building, those numbers should go up by a factor of 70 to 100, Alemu explains.

    The project involves much more than SIT, Alemu says. Conventional techniques such as traps and so-called targets—blue or black sheets sprayed with insecticide and baited with cow urine or artificial attractants—are currently used to drive down the population to less than 5% of its original level. SIT's role will be to finish it off, Alemu says, because sexual attraction can do what insecticides can't: reach and kill even the very last fly. The 25,000-km2 valley that has been selected as a first target is protected by mountains, reducing chances of reinfestation. It has only one species, Glossina pallidipes, which is what the factory is churning out at the moment.

    Later, it will have to start producing the country's four other Glossina species as well, because the goal is to rid all of Ethiopia—which is right on the northeastern edge of Africa's tsetse belt—of the flies. To prevent them from coming back, neighboring countries will have to adopt aggressive control programs as well, Alemu says.

    High costs, uncertain outcome

    The critics barely know where to begin.

    A technique that can drive down a population by 95% or 99% can also get rid of the remaining flies, says Stephen Torr of the University of Greenwich in the U.K. “There's nothing magical about that level,” he says, and past experience proves it.

    Tsetse were wiped out of an 11,500-km2 area in the western province of Zambia using odor-baited targets; Botswana got rid of tsetse flies in the 16,000-km2 Okavango Delta in 2 years by aerial spraying of very low amounts of insecticides, to which tsetse are extremely sensitive. (“They only have to look at it to drop dead,” Edinburgh's Maudlin says.)

    And there are many other reasons why SIT cannot work and is the wrong thing to try in Africa, critics say. Approximately 10 million km2 are infested, and there are 29 species and subspecies, of which at least seven are important from an economic or public health standpoint. Extrapolating from the experience in Zanzibar's 1600 square kilometers, infested by just one species, it would take 3500 centuries and $67 billion to do the same in all of Africa, David Molyneux of the Liverpool School of Tropical Medicine sneered in a 2001 commentary. What's more, experience shows that as a result of political instability, poor infrastructure, and bad governance, such complex operations aren't sustainable in Africa, says Maudlin.

    Will it fly?

    A worker in the mass-rearing facility outside Addis Abeba looks at a cage of tsetse flies.


    Finally, some say, the investments needed are too high given the uncertain outcome. IAEA doesn't fund SIT projects; however, it provides technical assistance, with countries picking up most of the tab. “Can you ask Ethiopia to spend $12 million on a factory if you're not even sure the technique will work on mainland Africa?” asks Bart Knols, a former IAEA staffer who's now at Wageningen University in the Netherlands. “To me, that's an ethical question.” (The total cost is unknown but will be much higher than $12 million, because the project is expected to take decades.)

    Zimbabwe's Vale says that IAEA, in its zeal to promote nuclear technology, has lost sight of all these problems.

    “Nonsense,” answers Assefa Mebrate, an Ethiopian ecologist and one of the founding fathers of the country's SIT project. IAEA didn't sell the country on anything, he says; it was Ethiopian scientists who saw SIT's potential and convinced the government to invest in it. And the expense is well worth it if it can bring about a permanent reduction in poverty. Mebrate deplores the fact that the vocal opposition, which he describes as a “cult,” has made donors shy of funding SIT in Africa.

    The head of IAEA's Insect Pest Control Section, Jorge Hendrichs, declined to be interviewed about tsetse and urged Science to instead write about SIT's success in the fight against the codling moth, a pest of pome fruit and walnut trees. But he did send a nine-page response to a list of e-mailed questions. “The IAEA is pushing nothing, but responds to demands from its member states,” Hendrichs wrote. “This is an Ethiopian project under the COMPLETE control of the Ethiopians.” It's a “fallacy” to think that conventional techniques can always kill off a population, he wrote, and IAEA believes in a role for SIT where they can't. “It is morally detestable,” he added, to claim that Africans should learn to live with the … problem because they are not capable of making projects sustainable.”

    Pie in the sky?

    The debate has also engulfed Africa's larger project, the Pan African Tsetse and Trypanosomiasis Eradication Campaign (PATTEC). Called into life by African leaders at a meeting in Togo in 2000, PATTEC advocates SIT as one tool in the continent-wide battle. Indeed, SIT is part of tsetse programs coordinated by PATTEC in Tanzania—which still has the fly factory from the Zanzibar campaign—and in Uganda and in Kenya, both of whom plan to build one. But even Mebrate, who firmly believes in the Ethiopian project, has doubts that Tanzania and Uganda can succeed with SIT, because they are targeting areas that are surrounded by infested areas and are thus much more prone to reinvasion.

    PATTEC head John Kabayo, a Ugandan biochemist who spent 6 years as a researcher at the IAEA lab, says, “People like to debate this issue until the cows come home.” He tries to avoid it, he says, because it's diverting attention from the real work. Insecticide spraying and targets will remain PATTEC's main tools, Kabayo says, and SIT is “a backup option.”

    Blood bank.

    To feed tsetse flies, cow blood, provided for free by a local slaughterhouse, is sterilized, frozen, and stored in a freezer.


    Meanwhile, a similar controversy is simmering over SIT's usefulness in combating malaria. With IAEA support, Sudan has just embarked on a project to fight the Anopheles arabiensis mosquito from the Nile valley in its Northern State; construction of a special mosquito factory is planned for Khartoum.

    Knols, who works as a consultant on the project, says that at IAEA, he repeatedly questioned whether Sudan, too poor to buy malaria drugs and bed nets, should pay for a SIT feasibility study. Given the lack of qualified staff, logistical nightmares, and the strained tensions with the Sudanese government as a result of the Darfur crisis, the country “probably wasn't the best place” to study the approach either, he adds.

    Paul Reiter of the Pasteur Institute in Paris calls the idea to tackle malaria in Africa with SIT “complete pie in the sky.”

    In Kaliti, the debate does not seem to bother the team managing the fly factory too much. They're mainly eager to get on with the project. Just recently, they have started releasing small numbers of sterile males in the project area, a day's drive from Kaliti. They are testing whether the sterile males can survive in nature and are still attractive to wild females—neither of which is guaranteed after 50 generations of lab life.

    The first results are very promising, says Alemu, who is convinced that the project—which he hopes will become a source of national pride—will eventually bear fruit. “We are very confident that we can do it, and we must succeed,” he says. “Ethiopia cannot live with the tsetse fly.”


    Proven Technology May Get a Makeover

    1. Martin Enserink

    The sterile insect technique (SIT) being tested in Ethiopia relies on two of the most formidable forces in the world: atomic energy and sex. Gamma radiation helps make male insects sterile, and sexual attraction ensures that released en masse, they will find females even in the most remote hideouts.

    Although its use in tsetse and malaria control is highly controversial, SIT has allowed several triumphs in insect control over the past 50 years, and its range of applications is expanding even today. Still, some believe the future may be a new, genetic version of SIT—one that keeps the sex but eliminates the radiation. One advantage is that it does not require the use of gamma ray sources, which terrorists could use to make dirty bombs.

    Scientists knew as early as the 1920s that x-rays and ionizing radiation produce dominant lethal mutations in male insects that effectively make them sterile. The idea to use sterility to control populations was developed independently in the 1930s and 1940s in the British colony of Tanganyika, the Soviet Union, and the United States.

    In the 1950s, U.S. pioneers Edward Knipling and Raymond Bushland put the idea in practice to fight the screwworm fly, a major pest whose larvae feed on the flesh of livestock and other animals. After a successful test run on the island of Curaçao, they took on Florida, and later, all of the U.S. states where the screwworm reigned. After victory was declared in 1966, the battle moved south, where through international cooperation, the flies were rolled back all the way through Mexico and Central America. Last year, a new screwworm-rearing plant was opened in Panama that produces 150 million flies weekly to guard the current frontier, close to the Colombian border.

    SIT is also widely used to prevent or suppress infestations of the Mediterranean fruit fly. A global pest, Medfly is a threat to everything from apples to tomatoes and pomegranates; being “Medfly-free” brings countries important trade benefits. Medfly factories have sprung up around the world. The largest, in Guatemala, produces more than 125 billion flies a year for several countries; huge numbers are dropped every week over the port cities of Los Angeles, Tampa, and Miami to prevent stowaways from causing outbreaks.

    Two months ago, a new Medfly-rearing plant was opened in the Spanish province of Valencia, a major citrus-exporting region. Meanwhile, a SIT program also helped eliminate the melon fly from islands in southern Japan between 1972 and 1993; and in the Netherlands, a company called The Green Fly sells environmentally conscious onion farmers sterile male onion flies.

    Fruitful fight.

    Factories around the world produce billions of sterile Mediterranean fruit flies every week to protect the global fruit industry.


    But lately, the spread of gamma ray sources such as cobalt-60 and cesium-130 to politically volatile countries has sparked concern. That's one reason the SIT lab at the International Atomic Energy Agency (IAEA) near Vienna, Austria, is now experimenting with x-rays as a way to sterilize males.

    A new method called “Release of Insects Carrying a Dominant Lethal” (RIDL) may provide another solution. Developed by Oxford University entomologist Luke Alphey and colleagues (Science, 31 March 2000, p. 2474), the technique doesn't actually sterilize released males but instead equips them with a gene that is lethal when expressed in females. As a result, they can only have male offspring, which in turn can only produce males, and so on. Models show that this can wipe out a population just as quickly as SIT, Alphey says.

    The technology, now in development at a company called Oxitech in Oxford, U.K., has already been used to create RIDL Medflies, Mexican fruit flies, and Aedes aegypti mosquitoes, which transmit the dengue virus. Entomologist Paul Reiter, who's currently testing the behavior and fitness of Alphey's Aedes mosquitoes at his Pasteur Institute lab in Paris, calls RIDL “very promising.” Many other entomologists are now using genetic tricks to make mosquitoes unable to transmit disease that could “replace” natural populations (Science, 30 March, p. 1777), but Reiter believes wiping out populations, as RIDL does, is more likely to work. However, RIDL comes with some of the same problems (see main text) as classical SIT.

    For the IAEA insect lab, a driving force behind many of the breakthroughs, radiation-free techniques would spell the end of its raison d'être: promoting peaceful cooperation in nuclear technology. But Jorge Hendrichs, who heads the section, is not worrying yet, because RIDL still has to prove its mettle. “The proponents of these molecular approaches underestimate the step from a small-scale lab experiment to an operational program,” he wrote in an e-mail to Science.


    Getting at the Roots of Killer Dust Storms

    1. Dennis Normile*
    1. With reporting by Gong Yidong of China Features.

    East Asia's dust storms are growing in number and ferocity. A simple experiment to wean villagers off destructive land practices suggests a way to tame the yellow blizzard

    A green revolution.

    Restricting grazing (inset) allowed this pasture in Inner Mongolia to recover naturally.


    BAYINHUSHU, CHINA—When Nasen Wuritu was a boy in this village in Inner Mongolia, “the grass grew as tall as an adult,” he says. In the 1960s, cows grazed year-round and never went hungry. After Nasen Wuritu reached adulthood, however, throngs of livestock had denuded the land, forcing him and other herders to spend precious cash on animal feed. Hand in hand with this crisis was a rising frequency and intensity of dust storms. “People couldn't go outside, and we had to light candles in the middle of the afternoon,” says Nasen Wuritu, now 50.

    In Bayinhushu, those hard times have passed. On a late spring day here, lush hills roll toward the horizon and the air is clear despite a steady wind. After a 5-year effort, the people of Bayinhushu—with help from officials and an army of ecologists, botanists, and economists—have restored the pastures. And dust storms here have abated.

    Bayinhushu is a rare bright spot in a bleak landscape. In the arid grasslands of northern China and Mongolia, overgrazing, over-cultivating, and squandering of scarce water resources have created a massive dust bowl where winds sweep topsoil away. Dust storms regularly blight eastern China, Korea, and Japan, closing schools, damaging jet engines, and triggering respiratory ailments as far away as California. A particularly nasty storm in May 1993 resulted in 85 deaths, the loss of 120,000 head of livestock, and the destruction of more than 4400 houses and 2.3 million hectares of crops, according to the Chinese Academy of Forestry Sciences. The economic toll in China alone is approximately $650 million a year, says Wang Tao, a physical geographer who heads a national project to combat desertification.

    Things are likely to get worse before they get better. Wang, who is based at the Cold and Arid Regions Environmental and Engineering Research Institute of the Chinese Academy of Sciences (CAS) in Lanzhou, estimates that northern China's arid grasslands are being degraded at a rate of 3600 square kilometers—an area bigger than the U.S. state of Rhode Island—every year. Wang predicts that as a result, dust storms, which have increased in number nearly sixfold over the past 20 years, will become more frequent, more intense, and more deadly.

    If the lessons of Bayinhushu can be applied across the vast steppes once ruled by Genghis Khan, dust storms should diminish. But there are challenges to implementing sustainable land practices in China's northern provinces. “Ecologically, it is easy to control dust storms. Economically, it is difficult,” says Bayinhushu project leader Jiang Gaoming, a plant ecologist at the CAS Institute of Botany in Beijing. Solutions must be tailored to the needs of local residents and ecological conditions in each region. Complicating the picture, top Chinese officials still hew to discredited policies that aim to subdue dust storms by conquering the deserts. “We have a lot of convincing to do,” Jiang says.

    Taking root.

    Jiang Gaoming shows how dense grass roots hold soil in place.


    The perfect dust storm

    The basic anatomy of East Asia's dust storms is fairly well established. For starters, the common term “sand storms” is a misnomer. Sand particles are too heavy to get lifted high into the atmosphere. Thus, little of the dust that blights East Asia comes from deserts, where erosion over the millennia has carried away most of the smaller particles. Studies indicate that the dust originates in dry lakebeds and arid lands on desert fringes. In these regions, a crust forms on undisturbed soil, giving some resistance to wind erosion. But in springtime, that crust is broken up by plowing and livestock, which also strip the land of new growth and pound soil into dust.

    Meanwhile, the temperature difference between a chilly atmosphere and a surface warmed by intensifying spring sunlight creates updrafts that lift dust into the air. As air streams south and east from Siberia, the winds bump up against the mountain ranges that ring northern China and Mongolia, forming low-pressure pockets that suck airborne dust into the upper atmosphere. Easterly winds sweep the particulate matter to Beijing, Seoul, Tokyo, and sometimes across the Pacific Ocean to North America.

    Don your masks!

    Beijing gets battered by dust in this 28 April 2005 image captured by NASA's Terra satellite.


    There are good years and bad years. Heavy snows add moisture to the soil, dampening dust in early spring. Conversely, without snow cover, soil dries out during winter and is more prone to wind erosion.

    This dynamic has persisted for centuries, as have dust storms. But the storms have been worsening. Seoul, which bears the brunt of East Asia's dust storms, suffered “dust events” on 23 days during the 1970s, 41 days in the 1980s, 70 days in the 1990s, and 96 days so far this decade, according to the Korea Meteorological Administration.

    The primary reason for this onslaught, most scientists believe, is degradation of fragile ecosystems. The population of Xilingol League, the district that includes Bayinhushu, increased from about 200,000 in the late 1940s to more than 950,000 in 2000, Jiang says. Over that period, herds of grazing animals skyrocketed from around 1 million head to more than 24 million, while the grazing area shrank from 5 hectares per animal to about one-tenth of a hectare.

    Staggering growth such as this occurred all across northern China. The national government encouraged nomadic herders to settle in villages and multiply herds to boost incomes, says Jiang. Livestock created an ever-widening ring of denuded land around settlements. The government also encouraged Han Chinese farmers to migrate to northern regions to “tame the deserts” with artificial oases and irrigation. The migrants cleared land for farms and cut brush for fuel. Irrigation gradually dried up many lakes and rivers. The result, Jiang says, is that 90% of China's grasslands, an area encompassing 4 million square kilometers, are degraded.

    Authorities have long recognized the problem, but attempted fixes have been futile if not counterproductive. Since 1978, China has spent at least $1 billion planting trees in arid and semiarid regions to combat desertification, says Luo Yiqi, an ecologist at the University of Oklahoma in Norman, who with colleagues at the Cold and Arid Regions Institute has studied such afforestation efforts.

    Afforestation is misguided, Luo asserts. “People proposed the idea without considering ecological principles,” he says. “They set out to create forests in regions where forests naturally do not grow due to limited precipitation.” The tree of choice has been the poplar. If watered, poplars grow rapidly, but without intensive care, they die. Sticks protruding from barren earth—dead poplar saplings—line roads in Inner Mongolia. Where poplar groves become established, Luo says, the deeply rooted trees hemorrhage water through transpiration, lowering the water table and making it harder for native grasses and shrubs to survive.

    China's tree-planting campaign has successfully reforested areas with ample rain, says Luo. But planting poplars in arid regions, he says, “does not help combat desertification.” The government continues to pour money into afforestation, regardless of water resources, through a bureaucracy whose mission is to plant trees. “It is time for the Chinese government … to scientifically evaluate long-term policies,” Luo says.

    Sustainable living

    In 2000, CAS applied a scientific approach to dust storms by funding five grassland-restoration pilot projects, including Jiang's. Jiang headed for Zhenglan County, a subdivision of Xilingol League, partly because the Institute of Botany has a research station there that had documented the loss of 12 centimeters of topsoil to wind erosion in the past 24 years. Another reason: Beijing is only 180 kilometers south. “If [the land] is degraded here, the dust will affect Beijing,” Jiang says.

    Realizing that the key to solving the dust problem is involving the people who live on the land—a big task given, Jiang says, “their poverty and their level of education”—he invited onto his team social scientists and economists as well as ecologists and animal husbandry specialists. The goal was to improve the lives of villagers while reducing environmental degradation. At the start of the 5-year, $600,000 project, Bayinhushu consisted of 72 households with 316 people and 11,560 head of livestock—75% sheep and goats, the rest cattle. The village manages 7330 hectares of land, much of it communal pasture.

    Jiang's team calculated that villagers could boost incomes if they reduced sheep and goat numbers and introduced an improved breed of dairy cattle, while curtailing open grazing. It was not easy to convince them, however. Mongols consider the size of the herd a measure of wealth. To help overcome doubts, local authorities chipped in additional incentives: They dug wells and extended the power grid to Bayinhushu to run pumps and electrify houses. The county also improved the dirt track connecting the village to a paved road.

    The villagers agreed to ban grazing on 2670 hectares of communal rangeland to allow vegetation to recover. Harvesting hay from this land in autumn provided enough forage for a smaller number of livestock during a typical winter, eliminating the expense of commercial feed. To tide the villagers over while the land recovered, Jiang's team planted corn on several dozen hectares.

    Jiang's team made some mistakes along the way. More than half of the initial budget went to aerial grass seeding and planting trees to form windbreaks. Both proved “a waste of money,” Jiang says. The trees died, and sown plots fared no better than those left to recover naturally.

    By and large, however, the simple plan worked. The villagers grew enough corn to feed animals without grazing in the common pasture. Herds were reduced to 5783 head, a little over half of which were sheep and goats. Milk production doubled per head. By the end of the third summer, the grass had recovered to provide more than enough hay for the village's needs.

    Five years later, Jiang says, the land looks much as it probably did a century ago. Annual incomes have increased 46%, from $315 to $460 per capita. In Nasen Wuritu's living room, a framed ceramic relief of Genghis Khan hangs on the wall. A large-screen TV and a satellite dish in the front yard pipe in previously unimagined entertainment. “We used to joke that there was nothing for Mongols to do at night but sleep and make babies,” Nasen Wuritu says. And the dust storms, which used to drive people indoors once or twice a month, are now occasional nuisances.

    Less is more.

    Nasen Wuritu saw his income increase after raising fewer animals.


    Bayinhushu is a “good example” of grassland restoration, Wang says. In an encouraging sign, herders in nearby villages are restricting grazing on communal pastures. Still, the Bayinhushu experience may not be easy to replicate in places with less favorable ecological conditions. Jiang notes that Bayinhushu had sufficient topsoil replete with seeds, and groundwater levels had not been affected by excessive irrigation.

    Severe degradation may require “human facilitation of the restoration process,” says Lu Qi, a desertification specialist at the Institute of Forestry in Beijing. After studying restoration projects on the Tibetan Plateau, where extreme degradation has created shifting sand dunes, Lu found that a hands-off approach led to a slow and spotty revegetation and little stabilization of the dunes. In contrast, erecting sand barriers and planting soil-stabilizing shrubs promoted the healthy recovery of native plants. Because shifting dunes smother new vegetation before it can take root, Lu argues that active intervention is needed to reverse desertification.

    The toughest task may be to undo the harm wrought by artificially expanding oases, like one at Minqin, between the Tengger Desert and the Badain Jaran Desert in Gansu Province, west of Inner Mongolia. Beginning in the 1950s, irrigation on a massive scale helped establish thousands of farms but eventually dried up natural rivers and depleted groundwater, fueling the expansion of the two deserts. Earlier this year, provincial authorities ordered 10,500 people to vacate farms in a 1000-km2 area surrounding Minqin within 3 ½ years.

    Wang says that resettling the farmers elsewhere “may relieve some problems in this area but cause new problems in another area.” It would be better, he argues, to introduce water-conservation techniques, such as those pioneered in Israel, which might allow sustainable farming in the area.

    At Bayinhushu, Jiang continues to measure the experiment's results and explore ways to further raise village incomes. The project is leaving an unexpected legacy. Before the project began, Nasen Wuritu says, village youngsters typically dropped out of school after the compulsory 9 years. But the scientists who spent time in the village exposed the youngsters to the Internet and text messaging. “Many young people realized the importance of an education,” he says. Exhibit A is Nasen Wuritu's eldest son, now studying to be a veterinarian at Inner Mongolia University in Hohhot. “He wants to stay in the city to pursue a better life,” Nasen Wuritu says. That would mean one less person eking out a living on the grasslands—and a greater chance of enjoying an environment increasingly liberated from dust.


    The Greening of Plant Genomics

    1. Elizabeth Pennisi

    As the National Plant Genome Initiative turns 10, it is beefing up its bioinformatics and its portfolio of sequenced crop and noncrop genomes

    In the genomics world, plants are second-class citizens. Researchers have sequenced the DNA of hundreds of microbes and dozens of animals, yet they have deciphered the genomes of just three plants, Arabidopsis, rice, and poplar—four, if you count Chlamydomonas, an alga. Comparisons between finned, legged, and feathered species have yielded tremendous insights into the evolution of these organisms. Yet plant biologists still lack the ability to compare the genomes of their favorite species, let alone begin to construct a coherent history of plants. No wonder plant researchers are complaining.


    At a 6 July workshop to evaluate the 10-year-old National Plant Genome Initiative (NPGI), experts in bioinformatics, plant breeding, and biotechnology called for more plant genomes to be sequenced and lamented the dearth of computational and analytical tools to evaluate genomes. Yet, at the same time, they praised the program for its progress to date. Over the past decade, NPGI has spent $780 million finding genes and sequencing plant DNA. That's a drop in the bucket, compared to more than $3 billion available from the National Human Genome Research Institute for decoding the genomes of humans and other animals, notes Jeff Dangl of the University of North Carolina, Chapel Hill. “Plant genomics research is a huge bang for the buck,” argues Dangl, who chairs the National Research Council panel charged with reviewing NPGI and recommending future directions.

    Congress kicked off this multiagency program in 1998. With prompting from U.S. corn growers, it earmarked $40 million for the National Science Foundation (NSF) to usher plants, in particular corn and other crops, into the genomics era. Now 10 years later, NSF, with additional support from the U.S. departments of Agriculture and Energy (DOE) and other federal agencies, has sponsored hundreds of genome-related projects.

    But researchers are clamoring for more DNA. At the meeting, Erik Legg of Syngenta, which is based in Research Triangle Park, North Carolina, called for more crop genomes. Eric Ward of the Two Blades Foundation in Durham, North Carolina, which supports the development of disease-resistant crops, cited the need for species that represent all the plant groups. Others argued for “resequencing” species from different places whose genomes are already known—say, Arabidopsis—to get a sense of the natural variation.

    Workshop participants also decried the genome initiative's lack of progress in bioinformatics. Funding agencies supported the sequencing of many animal species to help interpret the human genome. Toward that end, centralized databases, such as Ensembl, developed ways to compare genomes and look for conserved genes and pathways. That hasn't happened in the plant world. As a result, “data resources are balkanized,” complains Lincoln Stein, a bioinformaticist at Cold Spring Harbor Laboratory in New York state. For Arabidopsis sequence information, researchers go to a database called TAIR, but for corn, they head to MaizeGDB. “[You] can't go and see a comprehensive comparison between Arabidopsis and rice,” notes Ward. “It's frustrating.”

    Stein and others called for the integration of the various plant genome databases and for the establishment of uniform standards for characterizing genes and other DNA. “If you don't do this, your comparisons between genomes are utterly meaningless,” says Suzanna Lewis, a bioinformaticist at Lawrence Berkeley National Laboratory in California.

    NSF, DOE, and its collaborating agencies are taking steps to address these complaints. In late 2005, NSF awarded Washington University in St. Louis, Missouri, $29.5 million to sequence corn. Potato, tomato, and soybean sequencing is also under way. DOE's Joint Genome Institute in Walnut Creek, California, plans to devote increasingly more of its sequencing capacity to plants and microbes, curtailing its work with animals, says JGI's Daniel Rokhsar. All told, about two dozen species are in the sequencing hopper.

    NSF is pushing for better bioinformatics as well. It is reviewing proposals for a “plant cyberinfrastructure,” which will have the computers and know-how to meld the various sequence, gene-expression, functional genomics, and mutant databases to make possible one-stop shopping for genomics. NSF plans to spend up to $10 million a year for 5 years—10 years at most—to make these genomic resources accessible and to train researchers how to use them. Training is key, says Dangl. NPGI has “brought the mind frame of genomics to plant systems where there wasn't much before,” he notes.

    Indeed, NPGI has become “the major basic science program for plants,” says Jeffrey Bennetzen of the University of Georgia, Athens. The initiative will never have the resources of the National Human Genome Research Institute, but it is slowly lifting plants from second-class status.