News this Week

Science  25 Nov 2005:
Vol. 310, Issue 5752, pp. 1256
1. AVIAN INFLUENZA

China Will Attempt Largest-Ever Animal Vaccination Campaign

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

China watchers say it's no coincidence that the country announced a massive poultry-vaccination campaign just a day before confirmation of its first human fatality from the H5N1 strain of bird flu. “As long as it was in animals and not seen to be in humans, there was a certain complacency,” says Roy Wadia, spokesperson for the World Health Organization (WHO) in Beijing.

Public health experts welcomed the announcement as a sign that China is getting serious about bird flu, which has led to the death of more than 150 million birds in Asia and 67 human fatalities. China recently set up a national bird flu task force with $247 million to finance initiatives such as rewards for people who report unusual poultry deaths and compensation for farmers who lose birds. China's decision to vaccinate its entire poultry population—some 5 billion chickens, geese, and ducks—seems to be a recognition that the best way to keep H5N1 out of humans is to keep it out of birds. But as other countries in Asia have learned, there's more to vaccination than just jabbing chickens. Although experts increasingly agree that vaccination should be considered as a part of an H5N1 control strategy, it is hard to implement well. Countries must aggressively track circulating virus, for instance. And reaching every domestic bird, especially in a country like China, is difficult. Hong Kong, where H5N1 was first identified in 1997, has become a poster child for the strategy. Since it began vaccinating all domestic birds in early 2003, the territory has remained free from H5N1 infection. Vietnam is now in the midst of a vaccination campaign that will cover nearly all of the country's 200 million birds. A challenge with vaccination is distinguishing vaccinated from infected birds. One solution is to use a vaccine based on a slightly different virus strain, such as H5N2, which provides protection against H5N1 but allows birds to be distinguished by simple lab tests. Hong Kong is using an H5N2 vaccine and also placing unvaccinated sentinel birds among each flock. Vietnam, relying on international support, has opted to use a vaccine based on the H5N1 virus and to upgrade its lab facilities to do the more sophisticated testing required. China has been mostly using H5N1 vaccines, but details of its new campaign have not been released. But “vaccination by itself is not enough,” says Kitman Dyrting, senior veterinary officer with Hong Kong's Agriculture Fisheries and Conservation Department. It should be coupled with biosecurity measures, such as keeping domestic birds from contact with wild birds and sanitizing poultry farms—steps tricky to implement for backyard flocks. This is particularly relevant for mainland China, where an estimated 50% of all poultry are free ranging. Carolyn Benigno, a Bangkok-based animal health officer for the U.N. Food and Agriculture Organization, says that given the difficulty and expense of rapidly improving biosecurity for backyard holders, vaccination “could reduce the virus load in the environment.” China also plans to compensate farmers for losses, which will likely mean better reporting of outbreaks. Poorer farmers have been reluctant to tell authorities about sick birds, preferring to try to sell or eat them. And China will strengthen surveillance for human cases, particularly in provinces hit by outbreaks in poultry. A WHO expert team has been in China advising the country on field surveillance and lab work. Tests at a national lab have confirmed that a poultry worker died of H5N1 on 10 November, and an infected 9-year-old boy is recovering. His sister almost certainly died of an H5N1 infection, but the body was cremated before samples were taken. It's a puzzle why China had not recorded any human cases previously, says Wadia, as the virus has been circulating there since at least early 2004. If cases were missed in the past, he says, they are less likely to be missed in the future. 2. U.S. BUDGET NIH Set for Tiny Spending Hike in 2006 1. Jocelyn Kaiser Despite a surprise legislative setback, the National Institutes of Health (NIH) appears likely to receive the president's budget request for 2006—a 0.7% increase to$28.6 billion that leaves the agency with what one lobbyist calls "unpalatable choices." However, biomedical community leaders are heartened that Congress rejected a proposal to revoke funds for two NIH grants and accepted language that bolsters the independence of scientific advisory panels.

Last week, as part of a larger spending bill, House and Senate conferees agreed to increase NIH's budget by $253 million. That amount falls far short of a$1.05 billion boost that the Senate had passed and marks the third year of increases below biomedical inflation. And once $97 million earmarked for biodefense is removed, the final figure reflects a 0.5% boost—the smallest increase in 36 years. A rare rejection of the entire conference report by the House left the bill in limbo at press time, although observers don't foresee any changes to NIH's portion. Based on the conference report, Representative David Obey (D-WI) warned that NIH will be forced to fund 505 fewer new grants than in 2004. The agency also anticipates funding fewer training grants. "The agency is going to have to confront a series of unpalatable choices," says Dave Moore, head of governmental relations for the Association of American Medical Colleges. And the worst may not be over: Congress is weighing an across-the-board cut in all spending bills to pay for recovery costs from hurricanes Katrina and Rita and the president's proposed$7.1 billion pandemic flu plan, Moore says.

To the relief of biomedical scientists, the conference bill drops a House provision that would have revoked funds for two NIH grants studying visual perception in pigeons and factors involved in stable marriages (Science, 1 July, p. 29). And it retains a Senate amendment that would bar Health and Human Services (HHS) officials from asking candidates for scientific advisory committees about their political views—a response to such litmus tests earlier in the Bush Administration. The amendment also orders HHS not to use its budget "to disseminate scientific information that is deliberately false or misleading."

3. GENETICS

Expression of Endorphin Gene Favored in Human Evolution

1. Michael Balter

Humans and chimpanzees share at least 98% of their DNA sequences. Yet chimps are an endangered species, whereas humans have used their superior cognition to transform the face of the earth. What makes the difference? Thirty years ago, geneticist Mary-Claire King and biochemist Allan Wilson proposed that changes in how genes are regulated, rather than in the proteins they code for, was the key (Science, 11 April 1975, p. 107). A new study of evolutionary changes in the regulation of a gene implicated in perception, behavior, and memory suggests that King and Wilson may have been at least partly right.

Other researchers say that the new study is one of the first human examples of selection acting on a regulatory element, and it adds to a short list of brain genes now known to have been favored during the evolution of humans. “The evidence is compelling,” says evolutionary geneticist Bruce Lahn of the University of Chicago. But he and others note that it is not yet clear what mental or behavioral traits were favored by selection in this case.

An international team led by evolutionary biologist Gregory Wray of Duke University in Durham, North Carolina, focused on the gene that codes for the protein prodynorphin (PDYN), a precursor to a number of endorphins (opiatelike molecules involved in learning, the experience of pain, and social attachment and bonding). The PDYN gene is controlled by a promoter region just upstream from the gene's coding region. Earlier studies had highlighted a 68 DNA base pair (bp) segment of the promoter that varies among humans, who carry between one and four copies of it. It isn't clear how the number of copies and other variations in the segment affect the gene's function, although some variants have been linked to schizophrenia, cocaine addiction, and epilepsy.

Wray and his colleagues sequenced the promoter and some flanking DNA from 74 human chromosomes as well as 32 chromosomes from seven other primates, including chimps, gorillas, and orangutans. As the team reports in the December issue of PloS Biology, none of the nonhuman primates had more than one copy of the 68-bp segment. In addition, all human segments had five DNA mutations not seen in the other primates. The team concludes that the pattern is a solid example of natural selection acting on the human lineage after it split from the chimp line about 5 million to 7 million years ago.

To see whether the differences in promoters actually altered gene expression, the team introduced either the chimp or human 68-bp segment into human neural cells. The human segment induced a 20% greater expression of the PDYN gene than did the chimp segment.

The Wray team's work “speaks directly to King and Wilson's hypothesis,” says molecular biologist Sean Carroll of the University of Wisconsin, Madison. Carroll adds that the authors have provided a “road map” for experimental tests of the evolution of gene regulation. Evolutionary geneticist Svante Pääbo of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, agrees that the paper provides “convincing evidence for positive selection.” But Pääbo cautions that this one example does not prove that regulatory mutations were more important than structural mutations during human evolution.

Because of PDYN's importance in human biology, the authors suggest that the evolutionary changes in its regulation may have helped set chimps and humans apart. But Lahn says that such a conclusion is premature until researchers know more about why these changes were favored by natural selection. “It is a bit early to say that these changes were key to what makes us human,” Lahn says. “But it seems like a reasonable hypothesis.”

4. MEDICINE

1. Jean Marx

Every so often, research in one field suddenly bumps into another field. Take an enzyme known as LKB1. Discovered about 7 years ago as the product of a tumor-suppressor gene, LKB1 is now turning out to be a key regulator of the body's metabolic activities, including its handling of glucose—a discovery that connects LKB1 to type 2 diabetes and may explain its link to cancer.

The latest developments in the LKB1 saga, published online this week by Science (www.sciencemag.org/cgi/content/abstract/1120781), come from a team led by Reuben Shaw and Lewis Cantley of Beth Israel Deaconess Medical Center in Boston. Working with mice, the researchers have shown that the protein controls glucose production by the liver. In doing so, they've nailed down the mechanism of action for a drug that's been used to treat type 2 diabetes for nearly 50 years. Until now, it had been unclear how the drug, metformin, lowers a person's blood glucose.

The LKB1 gene was originally discovered in 1998 as the gene mutated in Peutz-Jeghers syndrome, a rare hereditary form of cancer usually affecting the intestines. Because the causative mutations inactivate the gene, it appeared to be a tumor suppressor. The gene's sequence indicated that it produces one of the cell's many kinases—enzymes that regulate the activity of other proteins by attaching phosphate groups to them—but its targets were unknown.

About 2 years ago, the Beth Israel Deaconess team and those of David Carling at Imperial College School of Medicine in London and Grahame Hardie at the University of Dundee, U.K., showed that LKB1 phosphorylates—and thus activates—a protein called AMPK (for AMP-activated protein kinase) that may help protect the body from metabolic diseases such as type 2 diabetes. Activity of AMPK leads to decreased glucose production by the liver as well as increased uptake of the sugar by muscle—both actions that would help keep blood glucose levels down. Cantley points out that this activity may contribute to LKB1's tumor-suppressive effects by depriving tumor cells of the energy they need to grow.

Since discovering that LKB1 activates AMPK in cell culture experiments, investigators have sought to confirm the relationship in living animals. A few months ago, Hardie's team, working with that of Dario Alessi, also at Dundee, reported in the EMBO Journal that reducing LKB1 gene expression to 10% of normal or less in the skeletal muscle of living mice greatly reduces AMPK activity, and consequently glucose uptake, in that tissue.

In the current work, Shaw genetically engineered mice so that the LKB1 gene was turned off only in the liver. Those animals, Cantley says, “had extremely high levels of serum glucose that were maintained for weeks.” The levels stayed up, he notes, even though the animals increased their production of insulin in response. These experiments confirm that LKB1 plays a “critical physiological role” in glucose metabolism, says Barbara Kahn of Beth Israel Deaconess, whose lab also works on AMPK.

Further experiments, performed in collaboration with Marc Montminy and colleagues at the Salk Institute for Biological Studies in San Diego, California, provided more information about how lack of LKB1, and the resulting decrease in AMPK activity, causes this persistent overproduction of glucose. Normally, AMPK phosphorylates a protein called TORC2, an alteration that keeps the protein in the cell cytoplasm. But when TORC2 is not phosphorylated, it enters the nucleus and turns on genes needed for glucose synthesis.

Previous work suggested that metformin works at least partly by stimulating AMPK activity in the liver. Shaw, Cantley, and their colleagues have now shown that although the drug stimulates AMPK phosphorylation in the livers of normal mice, it did not do so in mice whose livers could not produce LKB1. Nor did it decrease blood glucose concentrations in those animals. “This paper clinches” the idea that metformin exerts its effects through AMPK, Hardie says, although that enzyme apparently needs to be activated first by LKB1. And so a tumor-suppressor gene has solved a 50-year-old mystery about a diabetes drug.

5. SOCIETY FOR NEUROSCIENCE MEETING

Bats Have a Feel for Flight

1. Greg Miller

Even in total darkness, bats can execute complex aerial maneuvers to capture prey, thanks to their famed sonarlike skill of echolocation. At the Society for Neuroscience meeting in Washington, D.C., however, a researcher suggested that a long-ignored feature of bats' wings also helps the creatures perform midair acrobatics and catch insects.

In the 1780s, noted French biologist Georges Cuvier proposed that bats use their sense of touch to fly adeptly in the dark. About a decade later, naturalist Lazaro Spallanzani suggested that bats instead depend upon echolocation, but Cuvier fiercely criticized this competing hypothesis, and his reputation swayed most people at the time. Moreover, 19th century anatomists described a latticework of tiny bumps on bat wings that contain tactile receptor cells. It wasn't until the 1930s, when researchers first recorded the high-pitched sounds bats use to echolocate, that Cuvier's idea was finally dismissed in favor of Spallanzani's.

But John Zook, a biologist at Ohio University in Athens, remained curious about the tactile receptor cells. Taking a look at the tiny bumps under a microscope, he discovered that the cells appear very similar to Merkel cells, a common type of touch-sensing cell in the skin of mammals. The bat Merkel cells, however, had an additional feature: a tiny hair poking out of the center. When Zook recorded the electrical activity of the nerves connected to the Merkel cells, he found that they were very sensitive to air flowing across the wing surface. Because air turbulence can signal that a wing is losing lift, Zook reasoned that the hairs on the Merkel cells might help tell bats when to adjust the angle and curvature of their wings during tight maneuvers to avoid stalling out in midair.

To test this hypothesis, Zook treated two bats with Nair, a depilating cream more commonly applied to the human bikini zone. Then he videotaped the bats in flight. “They flew perfectly well—in a straight line,” he says. But when the bats had to make a 90-degree turn to avoid an obstacle, their elevation control was erratic. “Sometimes they hit the ceiling,” Zook says. When the hairs grew back, the bats regained their aviation skills.

Zook also described another type of receptor in the membranous part of bats' wings. Nerve recordings revealed that these receptors respond when the membrane stretches, even slightly. The most sensitive parts of the wing turned out to overlap with the “sweet spots” where the bats prefer to hit the insects they scoop up in midflight. (Zook mapped the sweet spots by videotaping the bats as they gathered mealworms shot out of an air cannon.)

Other bat researchers are impressed. “This is good stuff,” says neuroscientist James Simmons, who studies bat echolocation at Brown University. The work adds a new page to bats' remarkable résumé of sensory talents, he says. “It's very exciting work,” agrees Cynthia Moss of the University of Maryland, College Park. Moss says the study provides convincing evidence that bats' long-ignored somatosensory system is important for behavior. It seems Cuvier wasn't entirely wrong after all.

6. SOCIETY FOR NEUROSCIENCE MEETING

Neuroscience Society Plans to Leave New Orleans High and Dry

1. Yudhijit Bhattacharjee

How soon can New Orleans be rebuilt? The Society for Neuroscience (SfN) has decided that the answer is probably not in time for its 2009 annual meeting. That decision doesn't sit well with local neuroscientists, who see it as kicking their flood-ravaged city when it's down.

Six weeks ago, the society, which has been meeting in New Orleans every 3 years, decided to move its 2006 meeting to Atlanta and its 2009 meeting to Chicago. “The devastation caused by recent hurricanes and worry about future hurricanes' effect on the low-lying city has created a high degree of uncertainty about the ability of the city's … infrastructure to recover in time to host some 30,000 attendees,” said a statement on the society's Web site. Officials also ruled out 2009 based on “what is foreseeable at this time.”

Last week, the society's governing council voted to affirm the move but left open the possibility of revisiting the decision next spring after officials gather more information about the city's safety and redevelopment plans. “We were torn between ensuring that the meeting be held without snafus and sending a positive message to the New Orleans community,” says Darwin Berg, a council member and biologist at the University of California, San Diego.

Local researchers say the loss of the 2006 meeting is bad enough. But relocating the 2009 event amounts to “abandoning the city not just in its greatest hour of need but well into the future,” says Jeffrey Tasker of Tulane University.” It'll just make it more difficult to attract and retain scientific talent in New Orleans.”

Although some organizations have chosen to relocate their meetings in late 2006 and early 2007, SfN is the only one to have canceled in 2009, says Jeff Anding of the New Orleans Metropolitan Convention and Visitors Bureau. (The convention center plans to reopen in April.) The American Chemical Society and the American Physical Society are still planning to come in 2008, and the American Psychological Association is on track for next August.

7. SOCIETY FOR NEUROSCIENCE MEETING

Computer Game Sharpens Aging Minds

1. Greg Miller

Granny may not have the much-coveted Xbox 360 video game console on her Christmas list this year, but if a California company founded by neuroscientists has its way, computer games may soon become must-have items for seniors. Preliminary results presented at the meeting by company researchers suggest that a gamelike training program it has developed can improve memory and attention in elderly people.

The game, called HiFi, may lack the excitement of Grand Theft Auto, but it's designed to boost the function of the aging brain, says neuroscientist Henry Mahncke, vice president of research and outcomes for Posit Science, based in San Francisco, California. HiFi doesn't have a plot, per se, but offers several cartoonlike scenarios based on senior-friendly themes, including family and travel. In one part of HiFi, players collect photos of famous sites such as the Eiffel Tower by making increasingly difficult discriminations between whistling sounds that increase or decrease in frequency. The idea is to exercise and strengthen the neural circuits that process the acoustic building blocks of speech, Mahncke says. A similar approach has been used in computer games developed for children with language disabilities (Science, 5 January 1996, p. 27), several of which are now marketed by Scientific Learning Corp. of Oakland, California.

Older people often experience a decline in speech processing that can contribute to other types of problems, says Paula Tallal, a cognitive neuroscientist at Rutgers University in Newark, New Jersey, and co-director of Scientific Learning. (Tallal also sits on Posit Science's scientific advisory board, although she is not an author of the current study.) “If you can't process [speech] because it's going by too fast, you're not going to get it into memory,” says Tallal.

In a randomized trial of 95 healthy older adults with an average age of 80, those who played HiFi for an hour a day for 8 weeks improved their scores on a standardized test of memory and attention by an average of 5.5 points. A similar group who used a computer for an hour a day to watch a lecture improved about 2 points, no better than a third group who made no change to their daily activities. The seniors in the HiFi group performed like people 10 years younger typically would, Mahncke says.

But not everyone is convinced the improvement is all that dramatic. Dwight Dickinson, a neuropsychologist at the University of Maryland School of Medicine in Baltimore who uses computer training programs in his work with schizophrenia patients, suspects that the cognitive boosts reported so far aren't big enough to make much difference in people's day-to-day lives. It's analogous to getting a few extra IQ points, Dickinson says. Although he thinks the idea is worth pursuing, Dickinson is skeptical that computer training programs will undo time's inexorable toll on the brain. “You may be able to make changes around the edges, but you're not going to turn a 75-year-old back into a 40- or 50-year-old,” he says.

New Funding Schemes Aim to Retain Top Academic Talent

1. Wayne Kondro*
1. Wayne Kondro writes from Ottawa.

OTTAWA—As the general manager of a winning sports team knows, the secret to success is bringing on a superstar without losing existing talent. So too for university deans, who worry about raids from academic rivals while they are trolling for new talent.

To discourage such campus-hopping, the Canada Foundation for Innovation (CFI) has decided to give institutions a better chance of retaining their prized researchers. It's part of several programmatic changes at the foundation, an independent entity created by the government in 1997 to improve Canada's research infrastructure, as it prepares to spend the last billion dollars of a $3.1 billion endowment. One$262 million program has been tweaked to let universities—who receive block grants based on an assessment of faculty productivity—provide infrastructure for established as well as newly hired professors. CFI has also changed the rules for a core fund, which is preparing for a $276 million competition, to allow previous recipients to come back to the table for another bite. “If we hadn't done this, the danger would be a bit of a revolving door,” says CFI president Eliot Phillipson, who believes that retention of faculty has become as critical an issue in academia as recruitment. Allowing previous recipients to apply for upgrades, he adds, also acknowledges the rapid pace of technological change. University officials say the changes are a sign that Phillipson, the former dean of medicine at the University of Toronto (U of T), has been listening since taking charge of CFI in February 2004. Other new wrinkles include a$51 million fund to establish a national high-performance computing system and, possibly, other platforms in so-called enabling technologies such as digital data storage, retrieval, and publication.

James Turk, head of the Canadian Association of University Teachers, doubts that the changes will curb mobility. “A lot of academics look to move up the ladder,” he says. “I don't think this is going to change that dynamic.” But Michelle Gauthier of the Association of Universities and Colleges of Canada sees the changes as sound business practices that are long overdue. “If you look at any kind of standard for a solid management of an organization,” she says, “keeping good people is as important as attracting new ones.”

The new programs come with at least one string attached: Only 20% of an award will be available for operating and maintaining the new equipment, instruments, or research facility being funded. In the past, that share was 30%. Still, the approach “allows universities to customize their [spending] to [meet] their particular circumstances,” says Judith Chadwick, director of U of T's government research infrastructure program. And because the size of U of T's block grant will more than double, to $33 million, Chadwick isn't complaining. “We're thrilled,” she says. “I'm not looking a gift horse in the mouth.” 9. HIGHER EDUCATION U.S. Plans Suit to Stop Minority-Only Programs 1. Jeffrey Mervis Can a U.S. university participate in a federal program to increase the number of minority scientists without discriminating against the rest of the student population? That's the question facing Southern Illinois University (SIU) and the National Science Foundation (NSF) after the U.S. Department of Justice concluded this month that the university is violating the civil rights of Caucasian students by offering graduate fellowships to underrepresented minorities under an NSF program called “Bridges to the Doctorate.” The case is the latest skirmish in an ongoing battle over federal programs aimed at boosting the tiny percentage of Hispanics, African Americans, and Native Americans in the scientific workforce. Conservative groups such as the Virginia-based Center for Equal Opportunity (CEO), which flagged the SIU programs for the Justice Department, have pushed for the elimination of all racially exclusive programs at both the state and federal levels, and several universities have canceled such programs or changed their eligibility criteria (Science, 21 February 2003, p. 1167). But proponents say they are necessary to accomplish the goal of greater participation in science by minorities. In a 4 November letter, the Justice Department informed SIU officials that they have “engaged in a pattern or practice of intentional discrimination against whites, nonpreferred minorities, and males” by offering the Bridges program and two university-funded graduate fellowships that serve underrepresented minorities and women. The department said SIU could avoid being taken to federal court by canceling the programs and providing “make-whole relief” to the “victims.” It's the first such letter by the department to a university. Some 27 students participate in the SIU Bridges program, one of 18 sites around the country. The$17.8-million-a-year NSF program is an extension of the foundation's Louis Stokes Alliance for Minority Participation (LS-AMP) that serves undergraduates majoring in science and engineering. The SIU case highlights what NSF spokesperson Curt Suplee calls “our two different legal mandates.” Like every public agency, NSF swears it won't discriminate on the basis of race, religion, or national origin. Yet a 1980 law also gives it the authority to run programs to help minorities, women, and those with disabilities. “We are in compliance with both mandates,” says Suplee.

And that's the rub. CEO's Roger Clegg says race cannot be used as the overriding criterion for participation in any campus program. But Representative Chaka Fattah (D-PA), a member of the spending panel that funds NSF and a vocal supporter of targeted programs, sees such programs as critical for achieving an adequate domestic scientific workforce. “The intervention of the Justice Department contradicts 40 years of federal efforts, by presidents of both parties, to improve access to higher education by disadvantaged groups,” says Fattah.

SIU interim president Duane Stucky says the programs are part of the school's commitment to serving underrepresented students and that talks this week with the Justice Department are aimed at finding ways to preserve the programs.

10. AFTER KATRINA

Louisiana's Wetlands Struggle for Survival

More than 600 square kilometers of wetlands have disappeared in the last decade alone. After hurricanes Katrina and Rita—and a National Academies call for action—ecologists hope their large-scale plans will be implemented

LULING, LOUISIANA—From its headwaters in Minnesota to the Gulf of Mexico, the Mississippi is lined with massive earthen levees designed to prevent the mighty river from flooding. But here, 37 kilometers upstream from New Orleans, the Army Corps of Engineers and the state of Louisiana have spent $120 million to get a little flooding back. On a sunny October afternoon, inside a control room, a technician presses a button, and hydraulics begin to whine. Deep within the concrete structure, four steel sluice gates slowly rise, and the Mississippi springs a leak. With a gurgle, water from the Mississippi begins to flow through the four 16-square-meter culverts of the Davis Pond Freshwater Diversion Structure and into a 3-kilometer-long canal. Eventually, the water will reach the marshes of Barataria Bay, which, like much of coastal Louisiana, are starved of sediment. According to calculations by the corps, the water from Davis Pond should help preserve more than 13,000 hectares of Louisiana's endangered marshes—if it works, that is. Three years into the project, engineers have realized it's not easy to mimic a flood. Since Davis Pond began operation in 2002, engineers have struggled to get the water to flow properly and enough sediments to accumulate in the right places (see sidebar, p. 1265). And this effort is just a tiny fraction of what's needed to restore the devastated Louisiana coastline, a National Academy of Sciences (NAS) panel said this month. “The challenge of protecting and restoring this wetland system is unprecedented,” said the panel. According to the report,* the corps' current plan—an unfunded,$1.9 billion, 10-year proposal to slow down the destruction—is generally a good start, but it's by no means comprehensive enough. “This is really [just] the first step,” says Robert Dean, a civil and coastal engineer at the University of Florida, Gainesville, who chaired the committee. The academy is the latest in a long string of expert advisory bodies to call for urgent action. But its timing, less than 3 months after hurricanes Katrina and Rita devastated the coast and focused a spotlight on its problems, could make it the most influential. The question now is whether Louisiana, and the nation, will muster the political will and funds to set the course toward recovery.

Robbed of sediments

Coastal degradation was a problem long before Katrina roared into New Orleans. After the Army Corps tamed the Mississippi in the 1940s, the wetlands, deprived of the river's sediment, began to sink below sea level. Their health further deteriorated as extensive canals were dug, first to explore for oil and gas and then to pump them out. Adding insult to injury, a beaver-sized rodent called the nutria, introduced in the 1930s for its fur, turned out to have a voracious appetite for marsh plants. All told, more than 4000 square kilometers have been lost since 1950.

Faced with damage to marshes as well as impacts to wildlife, politicians began to address the problem in the 1960s. But despite many commissions and reports, there was little action until 1990, when federal legislation channeled about $50 million a year of funds to the state of Louisiana. Some 120 restoration projects are currently active, from hunting nutria to building new marshes with dredged silt. But these projects are small and piecemeal. After years of debate, in 1998, a coalition of state, federal, and local officials finally settled on an ambitious blueprint for reclaiming the coast. Called Coast 2050 (Science, 15 September 2000, p. 1860), it would have cost$14 billion over 30 years.

Notably short on details, the proposal had the lofty goal of creating a “sustainable ecosystem that supports and protects the environment, economy, and culture of southern Louisiana.” It won broad support, with 20 coastal parishes signing off on the concept.

But when the Army Corps presented its implementation plan to the Bush Administration in 2003, the White House balked at the cost. The corps was sent back to the drawing board with instructions to come up with something more modest to show that restoration was feasible. That irked leading restoration proponents, such as Robert Twilley of Louisiana State University (LSU) in Baton Rouge, who feel they already have the know-how to ramp up. “The science is there,” he says.

It is this scaled-down version, called the Louisiana Coastal Area (LCA) study and released in November 2004, that the state and the corps asked NAS to evaluate. Weighing in at a more modest $1.9 billion over 10 years, the LCA plan would spend$864 million on five major projects, some already in early stages of operation, and another $762 billion for 10 smaller projects that haven't been as fully designed, among other things. The NAS committee gave a thumbs-up to four of the five major projects, saying they were well conceived and technically feasible. These four included three sediment-diversion projects analogous to Davis Pond and an effort to restore an eroding headland and barrier island. But, reflecting long-held concerns among the scientific community and environmentalists, NAS politely suggested the Army Corps “reconsider” a fifth project, a plan to reinforce a major navigational canal, called the Mississippi River Gulf Outlet (MRGO, known as “Mister GO”). Dredged in 1963 to shorten the distance that ships have to travel to New Orleans, this 122-kilometer-long canal was widely faulted post-Katrina for making the city more vulnerable to flooding. Paul Kemp of LSU says that computer models suggest that it and other canals helped channel storm waters into New Orleans and surrounding parishes. MRGO has also been “an environmental nightmare,” says Donald Boesch of the University of Maryland Center for Environmental Science in Cambridge, who was on an earlier technical review committee for the corps. NAS noted that the canal has allowed waves to erode 81 square kilometers of wetlands over the past 40 years. By ferrying in saltwater, it has killed marshes and cypress swamps, too. NAS stopped short of recommending that MRGO simply be filled in, which John Day of LSU and many other scientists recommend. But it advises against spending$100 million to reinforce the shorelines, as the LCA proposal suggested. “We felt that that was probably not the best use of the available funds,” Dean says.

Missing game plan

The main problem with the LCA study is that it is “too modest an effort,” NAS concluded. By the corps' own calculations, the LCA study plan would slow the overall rate of land loss by only 20%, to 22.3 square kilometers per year. “It just isn't up to the massive deterioration of the Mississippi Delta,” says Day.

A second criticism is that the five projects are spread out across the state. The report speculates that “small projects [were] selected in order to navigate through the political obstacles that might derail efforts if focus is shifted to larger, more significant projects.” Although this may have political appeal, it's not a strategic approach that would place major projects in critical places where they would build on each other. Says Boesch: “You have to ask: What's the game plan?”

The Army Corps also needs to think bigger, the panel concluded. “There should be bolder, long-term sediment-delivery projects than were put forth in the [LCA study] plan,” says Dean. In particular, NAS detailed two projects that state and federal authorities should consider for greater study. One would divert the final reach of the Mississippi River westward, abandoning the so-called Bird's Foot Delta. The committee couldn't say how much land this would create—in principle quite a bit—or how much it would cost, because the corps has not evaluated the concept.

But, acknowledging the complexity of the undertaking, the committee also detailed the substantial side effects of this project. It would require the construction of a new navigational entrance to the river, for instance, and might also threaten the Delta National Wildlife Refuge and oil infrastructure in the delta.

The other project would divert water from the Mississippi River from a point about 100 kilometers upstream of New Orleans after building an 88-km-long channel to carry the flow to Barataria and Terrebonne Basins, just west of the Mississippi River. Depending on how much water flows through, this could create (or prevent the loss of) 28 to 56 square kilometers of land per year. Before any of this could happen, the Army Corp would have to buy much real estate for the canal and figure out how to compensate farm owners and others whose lands would be flooded. NAS raised the prospect of decades of legal challenges from property owners that “could prove insurmountable.”

Indeed, NAS didn't downplay the political or biological challenges facing the area. Parts of coastal Louisiana are in such bad shape that trying to fix some wetlands may be hopeless, and communities there may need to be abandoned. Picking which ones will not be easy. What's needed, according to NAS, is a new vision of what the Louisiana coast should look like. Such a map, drawn by federal, state, and local officials, would weigh the societal tradeoffs and chart where wetlands should be restored. Although the ambitious earlier plan, Coast 2050, had many of these elements, says Diane Reed of the University of New Orleans, it didn't explicitly spell out the consequences of the suggested actions, such as diversions changing oyster or shrimp habitat.

It's also important to move quickly from planning to action, scientists say. If barrier islands disappear, waves will strike wetlands with more force. “I'm concerned that if we wait around, we'll jump to a new level of wetland loss,” says Greg Stone of LSU. Furthermore, as energy costs increase, some restoration projects, such as dredging or pumping sediment through pipelines, may become too expensive.

Flood protection

The NAS report was almost completed when hurricanes Katrina and Rita hit, focusing national attention on how best to protect the city from future storms. While most of the attention has gone to investigating the failure of the levees (Science, 11 November, p. 953) and options for rebuilding them, many coastal scientists have plugged the role that healthy coasts could play in lessening storm damage. “If we don't restore the coast, any flood-protection system will function less well,” says Day. “We can't engineer a system that will protect New Orleans through levees alone.”

The report makes a brief nod in that direction: “To the extent that wetlands can offset a significant degree of storm impact, large-scale wetlands restoration projects can be an important component of national efforts to reduce future hazards from hurricanes.” The problem, the panel notes, is that there's little empirical evidence of the exact benefit that wetlands provide. An oft-quoted figure is that every kilometer of wetland reduces the storm surge by 7 centimeters, which comes from a few measurements of one hurricane in the 1960s. Better data come from Hurricane Andrew, which suggests that each kilometer of wetlands lowers the surge by 5 cm. Although that again can't be generalized, “there's no question that wetlands are better than open water,” Stone says.

Computer models are beginning to provide better estimates of the benefits. For example, Stone simulated a Category 3 hurricane hitting south-central Louisiana. He and his colleagues compared the effects of the storm on the coast, given the extent of wetlands in 1950, 1990, and 2020, if current losses continue. “There was a dramatic increase in storm surge,” Stone says. The past 40 years of decline led to a 2.5- to 3-meter increase in the height of storm surges, he says.

Even so, Reed says, it's unlikely that wetlands restoration would have done much to lessen the brunt of Katrina or Rita. “A really big storm is still a really big storm,” she says. Given the lack of evidence, Reed, for one, cautions against trying to persuade Congress to foot the restoration bill on these grounds. Levees will remain a key defense.

The importance of wetlands restoration, she and others say, is to ensure that coastal communities are still worth defending. And as the marshes go, so do habitats for oysters, shrimp, and fish that make up an industry valued at more than $3 billion—and the rich culture of the Bayou. Oil and gas infrastructure and jobs are threatened, too. As the coast slowly sinks and sea level rises, doing nothing means an inevitable retreat from the coast, says Bill Good of LSU: “Ultimately, the consequences are going to be worse than Hurricane Katrina.” • Drawing Louisiana's New Map: Addressing Land Loss in Coastal Louisiana, National Academies Press, 2005. 11. AFTER KATRINA Tapping a River to Restore and Build Up Wetlands 1. Erik Stokstad LULING, LOUISIANA—The Davis Pond diversion is just a small concrete building perched high on the riverbank. But it and another so-called freshwater diversion, located farther downstream, have sparked a huge controversy that demonstrates the political and technical challenges to restoring Louisiana's wetlands (see main text). Authorized in 1965, the diversions were intended to help fisheries by channeling fresh water from the Mississippi River into the marshes to dilute the encroaching saltwater. But the plans gathered dust until coastal restoration issues moved to the front burner in the late 1980s. That's when scientists realized that the marshes needed not just the right salinity but also fresh doses of river sediment. The Caernarvon Freshwater Diversion Project, located 24 kilometers downstream of New Orleans, was completed in 1991. But the large releases of water also triggered lawsuits over their impact on local oyster beds. The result was$1.3 billion of awards that were finally overturned last year by the state's Supreme Court. Scientists have determined that releasing pulses of river water can deliver sediment to the marshes while minimizing disruptions to other fisheries.

Having learned the hard way, the state spent $4 million to buy out existing oyster leases while Davis Pond was under construction. Opened in 2002, the project immediately ran into trouble when the discharged water backed up in the holding ponds, endangering a bridge. “We never got to the full range of tests before they had to pull the plug,” recalls Bill Good of Louisiana State University (LSU) in Baton Rouge, a former chair of the Davis Pond advisory committee. But prototypes are meant to illuminate problems, says Paul Kemp of LSU: “We need to bite the bullet and do the hard things.” And that, he says, should include an even more ambitious project to divert the entire Mississippi downstream of New Orleans. 12. AFTER KATRINA New Orleans Labs Start Their Uncertain Comeback 1. Jocelyn Kaiser Putting on a brave face as they begin returning to their flood-ravaged city, researchers are trying to resurrect their personal lives and research careers NEW ORLEANS, LOUISIANA—On the first full day in his lab after 10 weeks of hurricane-forced exile, Tulane University cancer researcher Matt Burow looks on with dismay as his gloved and masked research assistant Alberto Salvo holds out a scrap of brown tissue—a mouse tumor that sat at room temperature for weeks. “Everything liquefied. It just melted,” Burow says of the sample, which is now useless for protein analysis. Burow's group also lost 200 costly mutant mice, including a half-dozen that had just been injected with a promising antitumor chemical that took 2 months to extract from soybeans. Burow, who is just 34 years old but already has independent funding from the National Institutes of Health (NIH), says his research has been set back a year. Yet he tries to remain hopeful. “The only way you can really function is on the premise of faith that there's going to be support,” he says. “Because if [we] don't, we'll fall apart. Especially at this point in my career. You just have to hope we can catch up.” That forced optimism is shared by many researchers who began trickling back here earlier this month to restart their labs in the wake of the flooding caused by Hurricane Katrina. The city's two research powerhouses—Tulane University and Louisiana State University's (LSU's) Health Sciences Center (HSC)—don't expect to resume medical school classes in New Orleans before next summer, but administrators are scrambling to reopen laboratories, even in a city of boarded-up businesses, broken traffic lights, and armed patrols. The officials argue that opening labs quickly is necessary to hold on to faculty members who are now scattered at institutions across the country (Science, 23 September, p. 1980). Indeed, a few have already taken new positions elsewhere. “We need to secure the intellectual infrastructure of this place,” says Paul Whelton, senior vice president for health sciences at Tulane Medical Center. Those returning face a host of challenges, both professional and personal. Labs have lost many thousands of dollars' worth of biological samples, equipment, and research animals. New Orleans researchers are seeking funds to quickly replenish lost equipment and materials wherever they can, from federal agencies to scientific societies. They are also anxiously awaiting news that could prove crucial to their ability to resurrect their research: NIH and the National Science Foundation (NSF) must decide whether they can provide New Orleans investigators with 1-year funded extensions on expiring grants, given that the White House has already turned down NIH and NSF requests for additional funds to help Katrina-affected grantees. Numerous researchers, meanwhile, are struggling to rebuild or replace homes in neighborhoods devastated by floodwaters. Still, some researchers are positive. “I think we'll ride it out. We may be a little leaner and meaner, but we'll be back stronger than before,” says Tulane virologist Robert Garry. Others, however, are deeply worried about not only their own research but also whether new students, postdocs, and faculty members will commit to a devastated city with an uncertain future. “The ripple effect is going to be more painful to the institution than the initial shock was,” predicts LSU cell biologist Mark Alliegro. Lake LSU From his corner office eight stories up in LSU's downtown HSC, neuroscientist Nicolas Bazan asks a visitor to look out the window and picture the complex in early September, during the days after the levees broke. “Imagine there was a lake,” says the director of LSU's Neuroscience Center of Excellence. A roughly 2-meter high, black line is still visible on one of the white tiled buildings; it marks the high point of floodwaters in that part of the complex. Since mid-October, many of Bazan's 110 staff have been cleaning out their labs, wiping up mold, and tossing out spoiled cell cultures and reagents. “These floors were smelly; there were flies. It was extremely sad and overwhelming in many ways,” he says. Bazan is lucky: None of LSU's other downtown buildings is officially open yet. Scientists in those facilities have made forays into dark labs with flashlights to begin cleaning up and to retrieve computers. The biggest problem, say LSU officials, is that flooding damaged electrical switches and water pumps that now have to be repaired. LSU has also been slowed by state and Federal Emergency Management Agency (FEMA) rules requiring that rebuilding contracts be put up for bids. Plans now call for sealing off the first floors of buildings and allowing access to upper levels through walkways, says Joseph Moerschbaecher, vice chancellor for academic affairs at LSU's HSC. With the exception of the LSU-affiliated Children's Hospital in uptown New Orleans, which wasn't flooded and has taken in about 60 displaced researchers, the school has not yet set any firm date for fully reopening research labs—they're shooting for January to spring. Some researchers are “frustrated,” Moerschbaecher acknowledges. The recovery is further along at Tulane, a private university that doesn't have to follow the same bidding rules. In Tulane's main bio- medical research buildings, a few blocks from LSU and on the university's uptown campus, yellow tubes attached to dehumidifiers pump cold, dry air into the damp buildings around the clock. Researchers began coming back to a relatively unscathed building the week of 8 November and, once a damage inventory was done, set to work again. “There's an enormous sense of relief. We can make some of the pieces move forward,” says Donald Krogstad, Tulane's chair of tropical medicine. As they return, researchers are benefiting from some heroic efforts in the days after the flooding. Teams at both universities retrieved priceless cell lines, and many of Tulane's transgenic mice survived trips to temporary homes elsewhere. Accompanied by armed guards, some scientists went back to labs multiple times to keep Dewars stocked with nitrogen to preserve other materials. Indeed, tales of dedication and ingenuity abound: the maintenance worker who hot-wired a flooded elevator to get 135-kg Dewars moved and the staff at Tulane's suburban primate center who camped on the grounds and ate military rations for weeks to keep the center going, for example. Tulane saved its four nuclear magnetic resonance machines, whose magnets have to be kept close to 0 kelvin, thanks to an act of charity: A scientist described the problem to his neighbor, a welder, who had liquid helium flown in from one of his contacts. Still, there were huge losses. At Tulane, for example, one failed Dewar held 4 years' worth of cell lines of developmental biologist YiPing Chen, who has about$1 million in NIH grants. And LSU was forced to kill most of its mice, rabbits, dogs, and monkeys, which were largely kept on ground floors. The loss of thousands of animals and supplies and equipment for caring for them adds up to an estimated $10.5 million, says Moerschbaecher. At both campuses, anything in electricity-dependent refrigerators and -70°C freezers spoiled during weeks-long power outages—enzymes, antibodies, plasmids, bottles of serum, as well as pig hearts used by biomedical engineers. Some labs are also finding that equipment such as centrifuges and incubators didn't survive power surges and the soaring temperatures and humidity experienced by labs that were without air conditioning for weeks. Researchers estimate anywhere from$50,000 to hundreds of thousands of dollars in damages per lab.

Those conducting basic research aren't the only scientists who suffered losses. “Clinical and population researchers are very badly disrupted,” Whelton says. Twenty-seven freezers holding blood and urine samples from population studies were lost; the only studies that can probably be rescued will involve analyses of the stored DNA, which survived warm temperatures. The projects affected include a 33-year heart study following 8000 subjects and a multicenter chronic renal insufficiency study for which Tulane had the largest site. And given the citywide evacuation, clinical researchers have also lost their patients, many of whom need medications they were receiving for AIDS, cancer, or diabetes, says Laura Levy, Tulane University associate senior vice president for research. Universities are scrambling to track them down by telephoning contacts and placing ads in newspapers. They are also trying to decide what to do about the loss of Charity Hospital, the main site for Tulane and LSU clinical studies, which is now boarded up and too badly damaged to be saved.

Universities are still tallying the total damages to laboratories. But the cost will clearly be high: When Baylor College of Medicine's main medical school building in Houston, Texas, was hit by a flood 4 years ago, it sustained research damages of more than $100 million. “I wouldn't be surprised if it's hundreds of millions,” says Levy. Even at the University of New Orleans (UNO)—a state university that had a “growing research program” with about 28 NSF grants, says graduate school dean Robert Cashner—losses will total$5 million to $6 million dollars at a minimum. Officials say they expect to incorporate lessons from Katrina into future disaster plans. With the next hurricane season just 6 months away, LSU immunologist Seth Pincus is already taking preventive steps. For example, he learned that samples adequately stocked with liquid nitrogen can last for weeks—so he will make sure more large Dewars are on hand for cell lines and reagants. LSU's Iris Lindberg has also called for revising disaster plans so that LSU scientists, who were barred from their labs for 6 weeks, can have earlier access to retrieve valuable materials (Science, 11 November, p. 971). Still waiting for help Planning for future Katrinas could take significant amounts of money, but New Orleans institutions are finding it hard simply to cover the costs of bringing labs back to life. Insurance and FEMA will cover much of the damages, officials say. But getting the checks could take a long time—at Baylor, it took up to 4 years. “We need help right now,” says Whelton of Tulane. Many investigators have applied for supplemental grants from NSF and NIH. Some are accepting donations—a pharmacology society, for example, has given grad students$2000 stipends and exempted LSU researchers from paying meeting and journal fees, says Moerschbaecher. Drug companies have donated compounds, and vendors are offering discounts as high as 75% on reagents and research equipment.

Getting labs up and running is only half the battle. The other is making up for lost time. With many experiments destroyed, it will take months for scientists to get back to where they were. Institutions are asking federal research agencies to provide a year of additional funding for their grantees. After 15 years of NIH support, “I would hope I'd be given some time to make myself competitive again,” says Tulane's Steve Hill, who was on the verge of starting a clinical trial for a breast cancer treatment he had spent years studying in animals.

Whether that funding will come through is unclear, however. Federal agencies have been “so compassionate and responsive,” readily granting unfunded extensions for expiring grants, says Levy. But there's been no extra money yet. NIH Deputy Director for Extramural Research Norka Ruiz Bravo says the agency is waiting for scientists to fully assess damages and is working with FEMA on how to avoid duplicating reimbursement funds. How much overall funding is available may depend on NIH's 2006 budget—unlikely to be much higher than this year's—and whether NIH receives any money from Katrina relief bills passed by Congress. NIH has already asked the White House to request $150 million in post-Katrina recovery funds but has been turned down, according to biomedical lobbyists; a similar request from NSF was also rejected. If no extra money comes through, New Orleans's researchers will have to compete with other priorities. “We're very aware that there's a great need there. We'll keep that in mind,” Ruiz Bravo says. But she acknowledges that NIH had more resources to help researchers at Baylor, where flooding occurred when NIH's budget was booming. “It's a different budget environment,” she says. The disruption, meanwhile, has stalled expansion plans at both universities. Tulane “had been moving at a fantastic pace pre- Katrina,” says Whelton. It tripled its NIH grants over the past 5 years, rising to 86th among institutions with the most NIH funding, he notes. The university had hoped to double such funding again, but that strategic plan is now on hold. LSU, which had also been on a recruiting drive, hiring 100 faculty and three new department chairs in the last 4 years, is in even worse shape. HSC is losing revenue from a lack of patients, and the state is considering cutting money for higher education by at least 5%. LSU staff have already been laid off, and faculty could come next, says spokesperson Leslie Capo. “Money for recruiting's going to be very scarce,” says Pincus. Homeless but hopeful Even as they try to resurrect their labs, many investigators are dealing with staggering personal property losses. A number lived in flooded suburbs such as Lakeview, which is next to the failed 17th Street levee. A drive through this neighborhood is shocking—block after block of middle-class homes marked halfway up with flood lines, some with caved-in walls and roofs and muddy yards littered with overturned cars and fallen trees. Researchers who have salvageable homes are spending weekends cleaning up, often while putting in grueling commutes to teach medical students in Baton Rouge, where LSU is holding classes, or at Tulane's temporary campus in Houston—5 to 6 hours away. Some have sent spouses and children to live with relatives in distant cities. Universities are scrambling to locate places for faculty and lab workers to stay. UNO plans to find a place to put nearly 400 trailer homes provided by FEMA. LSU is considering cruise ships. Tulane, meanwhile, is hoping to entice back faculty members with families by co-launching a new charter school near campus. Still, scientists expect that some of their colleagues won't stay long or return at all, especially because most research grants are given to individuals and are not tied to an institution. “They're portable,” says Bazan. Tulane has already lost at least two researchers, a husband-wife couple. LSU has seen a half-dozen faculty members take slots elsewhere. Others aren't ruling out a move. “I'm keeping my options open. I can't afford to lose another 2 to 3 months of research time,” says LSU neuroscientist Jeffrey Magee, who is 40. Another worry is that graduate students and postdocs will no longer come. Any abandonment of New Orleans is premature, say some. Students and scientists don't realize that New Orleans is not the “hell on Earth” portrayed on television, says Tulane developmental biologist Peter Cserjesi, noting that restaurants are reopening, the French Quarter is coming alive at night, and crime is at an all-time low because so few people are left and the National Guard and police are patrolling the streets. But concerns about future hurricanes and the city's infrastructure are tough to shed, especially for outsiders. Some New Orleans researchers, for example, are protesting the Society for Neuroscience's decision to move its 2009 meeting from New Orleans (see News story, p. 1260). Among those who have returned, many share a sense of mission. “It's almost like people are coming back because they want to make a difference,” says molecular biologist John McLachlan, who runs a joint environmental center with Xavier University in New Orleans that has received a$200,000 NSF grant to coordinate post-Katrina research. “They want to save Tulane. They want to save the city. I think that's palpable and real.” But whether that goodwill will be enough to salvage science in New Orleans may not be known for a long time.

13. CONDENSED-MATTER PHYSICS

Researchers Turn Up the Heat In Superconductivity Hunt

1. Robert F. Service

Physicists still can't explain why some ceramic materials lose electrical resistance at relatively balmy temperatures, but they think they're on the right track

When Peter Johnson and colleagues set out to study the behavior of electrons in high-temperature superconductors, their experiments raised more than a few eyebrows. In 1999, Johnson, a physicist at Brookhaven National Laboratory in Upton, New York, systematically blasted electrons out of a superconductor with bursts of photons. The technique, called angle-resolved photoemission (ARPES), can reveal intricate details about how electrons behave inside a material. The Brookhaven team's results, however, flew in the face of other ARPES results as well as other types of electron-tracking experiments.

Today, things are falling into line. Armed with more precise-electron detectors, Johnson and his colleagues say the bumps and wiggles in their data better match other experimental results. Other photoemission experimenters, such as Z. X. Shen's group at Stanford University in Palo Alto, California, report a similar swerve toward consensus. “We are correcting ourselves, and Z. X. is happy to correct us as well,” Johnson quips.

That turnabout and others have convinced a number of researchers that they are closing in on what many view as the biggest mystery in condensed-matter physics: the mechanism that causes certain ceramics to superconduct at unusually high critical temperatures (Tc). But as experimental results grow ever more precise and convincing, just what they all mean remains highly contested. “There has been a tremendous amount of progress in the experiments,” says Mike Norman, a high-Tc theorist at Argonne National Laboratory in Illinois. “The data are pretty clear. But there is a lot of controversy about the interpretation,”

Controversy has been in steady supply since 1986, when Swiss physicists Georg Bednorz and Alex Müller discovered a class of copper-and-oxygen-containing ceramics called cuprates. The materials have since been shown to conduct electricity without resistance at temperatures as high as 138 kelvin—more than three times the temperature of the best metallic superconductors. As in those conventional superconductors, electrons in the cuprates pair up into “Cooper pairs” and surf through the material without the electrical friction typical of electrons traveling through other materials. Because all electrons carry a negative charge, they usually repel one another and don't want to pair up. But the rules change for superconductors. In the low-temperature metallic variety, a moving electron creates vibrations in the material's atomic lattice that pull another electron in its wake. It's these lattice vibrations, also known as phonons, that glue Cooper pairs together.

So what glues Cooper pairs together in high-temperature superconductors? After nearly 20 years of searching, physicists continue to battle over the answer. Perhaps the most prevalent view is that this pairing is driven by the magnetic behavior of the copper atoms in the atomic lattice of the cuprates: The presence of an electron on one copper atom causes nearby magnetic “spins” to align in a way that attracts another electron to sit nearby. Plenty of other researchers, however, argue in favor of phonons or some still more exotic mechanism.

Sorting out what is going on has been a headache in part because of the odd way in which the cuprates superconduct. In traditional superconductors, Cooper pairs surf through the material with the same ease in all directions. That's not the case with the cuprates. These materials have a complex layered structure that forces Cooper pairs to travel in the flat planes that contain copper and oxygen atoms. And even within these planes, they travel only along the two axes of the crystal, not along the 45° angles. When researchers map out the energy that binds Cooper pairs together versus their momentum (a product of their mass and velocity), they see a cloverleaf pattern, very different from what is seen in metallic superconductors.

Researchers initially turned to ARPES because it can track both the energy level of liberated electrons—which is determined in part by what other players the electrons are interacting with—and how this behavior changes with the electron's momentum. Other techniques reveal only the energy. But although early ARPES experiments did a fair job of nailing down the momentum, they couldn't come close to the energy resolution of other types of experiments. Over the past several years, the ability of the detectors to gauge the particular track of the electrons has improved 40-fold, and the energy resolution has skyrocketed as well. “The measurements are vastly superior to 10 years ago,” which has made ARPES an essential tool for investigating high-Tc materials, Norman says.

In Johnson's early photoemission experiments, he and his colleagues found that the electrons evicted from the cuprates had a broad range of energies. As they lowered the temperature of their sample from above the superconducting temperature to below it, the spread stayed about the same. That stability muddied the waters by suggesting that the researchers weren't seeing excited electrons interacting with any specific player in the material, such as a lattice vibration or type of magnetic fluctuation. In the parlance of physicists, they didn't see any “quasiparticles” in the superconducting state, which are essentially the combination of excited electrons together with the forces exciting them. Superconductivity in cuprates, it seemed, was due to a jumble of influences instead of a specific one.

That picture soon began to change when a company called Scienta came out with new, more-sensitive electron detectors, and it has been growing sharper ever since. Researchers led by Juan Campuzano at Argonne National Lab, for example, reported evidence in 2000 that quasi-particles were in fact present below the material's superconducting temperature. And this summer, after a series of very precise measurements, Johnson's team reported at a meeting that it largely agrees. Still, Johnson and others say that just what influences those quasi-particles represent remains unclear. But they're offering new hope that experimenters and theorists will soon pin them down. “It offers a signpost that we might be seeing something important,” says Daniel Dessau, a photoemission expert at the University of Colorado, Boulder, and the National Institute of Standards and Technology.

Another set of key signposts gives added reason for cheer. When researchers plot the energy of electrons liberated by a photoemission experiment against their momentum, they now regularly see what looks like a straight line with a kink in it, reminiscent of the bend in a flexible drinking straw. “The kink is an indication of a sudden change in the electron's velocity at a particular energy,” Shen explains. “There must be something making that change.” And the energy signature of that something is conspicuously close to the amount of energy that binds Cooper pairs together—suggesting that whatever gives rise to the kinks also acts as the mysterious glue for Cooper pairs.

In results reported at an American Physical Society meeting in March, for example, Dessau's team, working with photons from a high-power laser, sees a crystal-clear kink at 70 milli-electron volts (meV), an energy level that is most commonly associated with a phonon (see figure, above). Shen and colleagues working at the Hiroshima Synchrotron Radiation Center in Japan see a similar kink as well, which these and other groups had spotted with less resolution before. The catch is these electrons are traveling at a 45° angle to the crystal lattice—a direction, called the “node,” in which Cooper pairs can't travel. Because the electrons couldn't have been paired before being blasted out of the material, many researchers question how relevant this phonon is to the glue that holds Cooper pairs together. “This is not the node to study pairing,” Shen says.

Along the “antinode,” the 0° and 90° axes of the crystalline lattice, the picture is more confusing. Several groups, including Dessau's, see a kink there as well, at 40 meV. That suggests a different influence is acting on the electron. Shen and colleagues argue that their data point to a separate phonon from the 70-meV version present along the node. But for now, many other researchers don't agree. “The other groups are fairly insistent that it is not a phonon effect along the antinode,” Norman says. Most of these teams suggest that the kink is caused by a collective magnetic behavior of the electrons. The wrinkle, Johnson says, is that both the phonons and the magnetic excitations would likely have about the same energy signature, so it is hard to tell which one is playing the key role. But the recent progress in ARPES and other experiments has many high-Tc researchers feeling more confident than ever that they will find the answer soon. Says Norman: “I think it will be sorted out in the next couple of years.”

14. SPACE SCIENCE

The Question on the Table: Will Europe Go to Mars?

1. Daniel Clery

At a meeting in Berlin next month, members of the European Space Agency will be asked to invest in Aurora, a still-evolving scheme to explore the solar system

CAMBRIDGE, U.K.—Next month, when ministers from the 15 member states in the European Space Agency (ESA) meet in Berlin to discuss the next 5-year chunk of funding, they will face an important question: Is it time for Europe to forge its own path among the planets? European governments made a tentative move in this direction in 2000—several years before President George W. Bush committed the United States to going to the moon and Mars—by asking ESA to lay the groundwork for human exploration of the solar system. In 2001, this program got a name—Aurora—and some seed money. Now it is time to write a big check.

Aurora, if it goes, will be small by NASA's standards. In its first decade, it will consist principally of a single robotic mission, known as ExoMars, and technology development for a future Mars sample-return mission and human exploration. ESA next month will request a budget in the region of $800 million to$950 million for Aurora over the next 5 years.

Although the program is beginning modestly, it is symbolic of the agency's burgeoning ambitions and Europe's desire to assert its independence in space. “Europe now has greater confidence and capability in planetary exploration,” says astrophysicist Ken Pounds of the University of Leicester, a former chief executive of the United Kingdom's Particle Physics and Astronomy Research Council. And to underline this new spirit of bravado, ESA also wants to collaborate with Russia to build a minishuttle called Clipper that would carry up to six astronauts into space.

As a rule, space agencies' plans tend to outrun their available budgets. Whereas NASA must go to Congress every year to get its budget approved and make good the cost overruns, ESA walks a different financial tightrope: It must persuade 15 governments to agree on its funding once every 5 years or so— as it hopes to do in Berlin on 5 to 6 December.

ESA's science missions often fare badly in this process because science is one of the agency's few mandatory programs, to which every member state contributes in proportion to its gross national product. That may seem like a formula for assured funding, but because all the members have to agree on the total sum, the science budget has remained static for about a decade. ESA officials aim to break Aurora out of that straitjacket by casting it as an optional program: Each member can contribute as much or as little as it likes and receive back funding for its researchers or industry contracts in proportion to its contribution. ESA's leaders hope Aurora will be attractive enough to win funding in its own right, and they are busy selling the concept.

“We've been working closely with most of the delegations with an interest in ExoMars,” says Piero Messina of the exploration program at ESA headquarters in Paris. “We hope this will pay off.” ExoMars is something of a carrot to lure member states into Aurora. Following on from ESA's successful Mars Express orbiter, the baseline version of ExoMars will consist of two parts: a rover that will be able to drill into rocks and burrow beneath the surface in search of samples, which can then be analyzed onboard for signs of life, and a static base station with environmental and geophysics instruments.

ExoMars will also be a test bed for essential technologies, including hardware for descent and landing, power supply, and communications. Finally, it will assess what sorts of hazards future human visitors might face. “We sense that the interest in ExoMars is such that it may attract more money than the baseline,” Messina says. If member states pledge more than the $700 million ESA is seeking for ExoMars, the agency may be able to add an orbiter that will act as a communications relay while studying the planet's surface from space. The potential sticking point in next month's negotiations is that member states are divided on the long-term goal of sending human beings to explore the solar system. ESA already has a corps of astronauts, but no vehicle to carry them in: They must travel as guests aboard the shuttle or Soyuz. The United Kingdom has a decades-long policy of not participating in programs involving humans in space because of the huge investment required, and sources say Germany, too, may be reluctant to join Aurora if it emphasizes human exploration. Earlier this year, the United Kingdom's Royal Astronomical Society asked a panel of three prominent scientists, including Pounds, to investigate the case for human exploration of the solar system. They were skeptical from the start, having seen the billions squandered on the international space station produce little scientific return. But after 9 months of investigation, they were convinced that for the foreseeable future, robots would be unlikely to be adept enough to provide answers to important questions such as the history of the solar system and the existence, or not, of life on Mars. The United Kingdom, they concluded, should abandon its policy of avoiding all human missions. “Do we want to be in there, or standing by watching?” asks Pounds. Despite such encouragement, ESA foresaw that the human issue would continue to be a problem for some member states, and it has toned down those parts of the Aurora proposal, for the early years at least. “For the moment, there is no human element,” says Roger Bonnet, former director of science at ESA, who now heads the International Space Science Institute in Bern, Switzerland. Another potential area of uncertainty is the extent to which Aurora will require collaboration with other space agencies. ExoMars “is clearly an ESA mission,” says Messina. The sample-return mission that is to follow it “was always conceived as an international endeavor, but [whether] partners will be ready or willing is uncertain” because “calendars have to match,” he explains. Aurora officials and their opposite numbers at NASA have had regular meetings, but Messina says U.S. plans are still in flux. Although ESA officials may talk big, realistically Europe is never going to send astronauts to Mars on its own. “Aurora is about enhancing our knowledge of Mars, getting technology ready, keeping an eye on the plans of other nations, and identifying the building blocks that ESA can contribute,” Messina says. While ESA is keeping an eye on NASA to set the pace for a visit to Mars, it is looking to the East in search of a vehicle to get astronauts into space. NASA has made it clear that it does not want any international help in developing its Crew Exploration Vehicle, the successor to the shuttle. However, earlier this year, the Russian space agency approached ESA to suggest teaming up to develop Clipper, which Russia has been working on since 2000 as a replacement for the venerable Soyuz capsule. In June, the two agencies inked an agreement to carry out 2 years of joint studies beginning in January 2006, assuming that ESA members agree to the$60 million price tag at the Berlin meeting.

Clipper would be lofted into space with an existing launcher, such as Russia's Angara or Ukraine's Zenit, and it would glide down to land on a runway. The aim is to have an initial unpiloted flight in 2011 and to carry the first passengers in 2012 or 2013. Initially, it will take over from Soyuz in ferrying crew back and forth to the international space station, but, says Manuel Valls of ESA's Human Spaceflight Directorate, it is not designed to provide a taxi service: “It's an exploration vehicle. It could go to the moon, provided with appropriate propulsion.” The agencies are reluctant to talk about the total cost of development, but it is likely to be somewhere in the region of $2 billion to$3.5 billion. Russia has also asked Japan to join the collaboration; a decision from Tokyo is expected during December.

Next month's meeting will reveal whether European politicians share ESA's enthusiasm for sending their citizens into the final frontier. Buying into the Aurora program would be the down payment.