News this Week

Science  26 Jan 2007:
Vol. 315, Issue 5811, pp. 444

You are currently viewing the .

View Full Text

Log in to view the full text

Log in through your institution

Log in through your institution


    New Congress May Be Warming Up to Plans for Capping Emissions

    1. Eli Kintisch
    Pact men.

    GE's Jeffrey Immelt (left) and WRI's Jonathan Lash helped organize an industry-environmentalist partnership on climate change.


    The first winter storm of the season, long overdue, blew through Washington, D.C., last weekend. But proponents of federal legislation to limit carbon emissions continued to bask in the glow of increasing support for their cause.

    The new Democratic majority in both houses of Congress has made it more likely that a bill capping carbon emissions will land on President George W. Bush's desk before he leaves office in January 2009. Of course, the final form of any legislation will be shaped by the demands of various powerful industries, and it could well encounter a presidential veto. But few question the newfound political momentum behind some type of federal action. “The tide is turning,” says Jonathan Lash of the nonprofit World Resources Institute (WRI) in Washington D.C., which has joined a new partnership between environmentalists and industry announced this week.

    The president's State of the Union address, delivered after Science went to press, was expected to focus on ethanol as part of a nonmandatory climate strategy. But most observers expect Congress to be more aggressive in tackling greenhouse gas emissions. Two senators hoping to become president, Arizona Republican John McCain and Illinois Democrat Barack Obama, have cosponsored a bill that would slash emissions steeply by 2050. And on 22 January, the newly formed United States Climate Action Partnership, a group that includes 10 major U.S. companies such as General Electric and BP American as well as WRI and the Natural Resources Defense Council (NRDC), advocated for a “mandatory [and] flexible” emissions trading system that has impressed energy analysts.

    “You couldn't have imagined 2 years ago a group of such companies getting behind such targets,” says Jason Grumet of the National Commission on Energy Policy in Washington, D.C., a similar consensus-building group that in 2004 recommended less aggressive goals. NRDC's David Doniger says the conventional wisdom at the time was that the group's principles went as “far as the political center of gravity would go.” In 2005, for example, then-energy committee chair Senator Pete Dominici (R-NM) urged Congress to “proactively address climate change.” But the best that the Republican-led body could do was make a vague, nonbinding statement calling for “mandatory steps” to cap greenhouse gas emissions. House Republicans stuck to voluntary approaches while promoting federal research.

    The statement by the new climate partnership is easily the most aggressive yet from industry. It aims to halt growth of U.S. emissions within a decade and to lower current levels by 60% to 80% by 2050. The group wants to control the cost of emission permits, perhaps with a price limit, but not in a way that would undermine the system, and to bar old-fashioned coal plants from getting free credits. Coalition members say they want to avoid piecemeal state emissions caps, such as a tough new California system, and more draconian measures down the road.

    Another set of once-odd bedfellows also lobbied Congress last week. “We dare to imagine a world in which science and religion cooperate” to tackle climate change and other problems, said Reverend Richard Cizik of the National Association of Evangelicals (NAE), one of several evangelical Christian leaders who have joined with Harvard entomologist E. O. Wilson and Missouri Botanical Garden botanist Peter Raven and other researchers for “responsible care for creation.” NAE has agreed to distribute a “pastor's tool kit” with information on the warming atmosphere and other environmental problems to counter what Cizik calls “junk science” from climate skeptics.

    Such coalitions seem likely to strengthen the hand of lawmakers such as Senator Barbara Boxer (D-CA), head of the Environment and Public Works committee, who wants to pass a carbon cap “as soon as possible.” House Speaker Nancy Pelosi (D-CA), meanwhile, has created a special committee to explore and publicize climate change legislation. House energy committee chair and auto industry supporter John Dingell (D-MI) opposes the new committee, which won't have legislative authority. But its creation, says Grumet, demonstrates that Pelosi “is not going to defer to the committee structure” in moving her agenda.

    Yet aggressive action won't be easy. Some of the 49 Republicans in the 100-seat Senate will be needed to override a veto by the White House of any emissions legislation, notes Senate Energy committee staff director Robert Simon. McCain and Obama's bill is a positive step, says another aide, but is unlikely to win the support of a majority of senators.


    LUNAR-A Moon Mission Gets an 'F'

    1. Dennis Normile

    TOKYO—A mission to explore the moon's origin and evolution has crashed before launch. Earlier this month, Japan's space agency terminated its LUNAR-A probe because its ambitious technology was still not ready to go even after the launch had been delayed for 12 years.


    The LUNAR-A orbiter has been ready for years, but problems with the payload led to its cancellation.


    The cancellation of the ill-starred mission has sent tremors through the global space science community. “The feeling is one of uniform regret that this mission is not flying,” says Clive Neal, a geologist at the University of Notre Dame in South Bend, Indiana. Despite the setback, Japan's space scientists say they remain committed to pursuing technically challenging ventures.

    Planned by the Institute of Space and Astronautical Science (ISAS) in Sagamihara, near Tokyo, LUNAR-A called for an orbiting spacecraft to drop two torpedoshaped probes onto the moon's surface—one on the near side and one on the far side. These “penetrators” would lodge 2 meters below the surface, activating seismometers to detect faint moonquakes and other sensors to measure heat flow, then relay the data to Earth. Scientists had hoped to deduce details of the largely unknown lunar interior, such as whether the moon has an iron core. A better picture of lunar anatomy would constrain models of how the moon formed.

    Mission planning began with high hopes in the early 1990s. While ISAS planetary scientists sketched out key unresolved questions about the moon's interior, colleagues on the engineering side huddled over how to get inside the moon. They opted to design a probe to drop from orbit and embed instruments firmly, and intact, in the lunar soil—something that has never been tried before. They thought this would be more practical than developing a rover to traverse the moon's expanses, says Manabu Kato, an ISAS planetary scientist. And burying the instruments would shield them from the extreme day-night temperature fluctuations that fried instruments left on the surface by previous missions.

    By 1995—the planned launch date—the orbiter was ready to go. The penetrators were not. They're still not, even after 12 additional years of development and escalating costs; the original price tag for the satellite alone was $106 million, and $132 million has been spent so far.

    What went wrong? Kato says the team vastly underestimated the challenges of girding instruments and electronics to survive an impact imparting a force of up to 10,000 times that of gravity. “Modeling had indicated that just some hardening of components would be sufficient,” Kato says. But testing proved otherwise.

    The first snag was finding a proper test site. Only after the first launch date passed did engineers realize that ISAS lacked suitable equipment and facilities. In 1997, with the project already 2 years behind schedule, they finally found an adequate testing ground: Sandia National Laboratories in Albuquerque, New Mexico. There, a device akin to a giant upside-down cannon uses explosives to fire test penetrators into the sandy earth. But due to schedule constraints, ISAS could use the Sandia facilities only once every 10 months, resulting in an excruciatingly slow process of trial and error. At last, after the instruments were hardened sufficiently, ISAS engineers determined that the electrical wiring was too frail. Once that was fixed, they found that they had to develop a circuit to reset the CPU after impact. The launch date slipped again and again.

    During the most recent round of testing, in June 2006, the scientific instruments, circuits, and software all passed muster, Kato says. But further work is necessary to make the communications systems more robust, he says. Another round of testing is scheduled for this summer.

    That's too late to save LUNAR-A. After a series of internal reviews, ISAS's parent organization, the Japan Aerospace Exploration Agency (JAXA), on 15 January scrapped the mission. A JAXA spokesperson says the decision was based on the orbiter's deterioration in storage and the fact that the penetrators are not ready for prime time.

    Not all hope is lost. Takashi Nakajima, current LUNAR-A manager, says that the penetrator project is not being abandoned. ISAS will complete development work and then try to get the penetrators loaded on another moon mission. “Researchers will still request this kind of investigation,” says Hitoshi Mizutani, a space scientist who headed the mission until his retirement 2 years ago.

    Planetary scientists outside Japan agree. “The community would very much like to see a geophysical network on the moon to study internal structure and heat flow, but two penetrators do not make a network,” says Andrew Cheng, a planetary scientist at Johns Hopkins University in Baltimore, Maryland. Kato says ISAS had hoped LUNAR-A would gather enough data to determine whether the moon has an iron core, proving that the penetrators work. Subsequent missions could have then expanded their use on the moon and, perhaps, Mars.

    But he vows that ISAS will remain at the forefront of space engineering and space science. “If you don't develop new technologies, you won't make new scientific discoveries,” Kato says.

    ISAS's next marriage of engineering and science is its $300 million Selenological and Engineering Explorer (SELENE). Set for launch in late March, SELENE comprises an orbiter and a pair of smaller satellites that will aim instruments at the moon to collect the most detailed data yet on its topography, the elemental makeup of its surface, its magnetism, and its gravitational field. “We're confident,” says Kato. “We've tested it, and we're ready to go.” If so, that would take some of the sting out of the humbling demise of LUNAR-A.


    India Inches Closer to Crewed Space Flight

    1. Pallava Bagla

    THIRUVANANTHAPURAM, KERALA—India took another small step this week toward a place at the top table of space-faring nations. The Indian Space Research Organization (ISRO) launched a crewless spacecraft into orbit on 10 January, and on 22 January, controllers guided it back to Earth for a splashdown in the Bay of Bengal, 140 kilometers from its launch site. The feat of launching and retrieving a probe has to date only been achieved by Russia, the United States, and China, and is an essential step toward sending astronauts into orbit. “Both the launch and splashdown of the space capsule were completed with textbook precision,” says ISRO spokesperson S. Krishnamurthy.

    The Space Capsule Recovery Experiment is part of an effort to eventually launch Indian nationals into space. Toward that goal, the 5000 researchers here at the Vikram Sarabhai Space Center hope to launch another experimental capsule soon. In 2008, the plan calls for the launch of a remote-sensing mission to the moon called Chandrayaan-1. The first Indian in orbit is planned for 2014, with astronauts on the moon by 2020. ISRO is seeking $250 million in start-up funds to loft the first astronaut.

    One of the key technologies on test during the recovery experiment was thermal protection to shield potential astronauts from the intense heat caused by friction during reentry. A team of 40 researchers here produced the lightweight heat-resistant materials made from pure silica that coated the outside of the 550-kilogram capsule. “The thermal protection system was one of the important experiments being carried out in the space recovery module. This is a precursor for all forthcoming reusable launch vehicles—and in the long run, to the manned mission too,” says space center director B. N. Suresh.

    The mission also carried two materials science experiments in which crystals were grown under near-zero-gravity conditions. Researchers are now studying the capsule to see whether all the experiments went according to plan.


    Report Backs NSF Prize to Spur Innovation

    1. Jeffrey Mervis

    The National Science Foundation (NSF) should test the waters before plunging into a costly program to award prizes to encourage innovation. That's the verdict of an expert panel of the National Academies' National Research Council, which has cautiously endorsed an idea Congress had ordered NSF to consider. Ironically, legislators may have lost interest.

    In 2005, Representative Frank Wolf (R-VA), then chair of the spending panel that sets NSF's budget, asked the agency to think about offering megaprizes for solutions to important scientific challenges with societal implications. At one hearing, for example, Wolf speculated about how a $1 billion prize could yield an elegant technological solution to the nation's dependence on foreign oil. Last summer, NSF officials turned for guidance to the National Academies, which this week issued a 44-page report urging NSF to adopt “an experimental approach” by piloting a handful of small prizes before considering spending big bucks.

    Such prizes are useful, says panelist and former NSF Director Erich Bloch, “because they bring in new people who don't normally participate in government programs and because it allows you to tackle controversial ideas. But I wouldn't spend $1 billion on it.”

    Panel chair Mark Myers, a retired research executive at Xerox, believes that NSF “needs to develop a methodology” on how to run such a program and then evaluate each step of the way. The panel did not recommend any topics for NSF to tackle, although for illustrative purposes it mentioned areas such as nano self-assembly, green chemistry, low-carbon energy technologies, and teaching software. The report suggests that NSF should start with a handful of prizes ranging from $200,000 to $2 million and raise the payout to as much as $30 million if the concept proves successful. Myers says Congress should increase NSF's budget to make room for the program so that its cost doesn't undermine ongoing activities.


    The self-assembly of nano-scale materials might be the sort of technology ripe for an NSF contest.


    The report recommends starting the prizes this year, but with NSF facing a budget freeze (Science, 5 January, p. 24), that's not likely to happen. “It's a solid report, and piloting is always the right way to go,” says senior NSF administrator Nathaniel Pitts, who has tracked the issue. “But it's an expensive proposition, and I don't see how we could afford it this year.”

    An even bigger obstacle, however, may be the recent changes on Capitol Hill. Wolf is no longer on the spending subpanel, and House Republicans are in the minority. A Democratic aide on the House Committee on Science and Technology, which oversees NSF, says that prizes probably make more sense at a mission-oriented agency such as NASA or the Defense Department. And the aide questions the idea that a prize will attract new players into the research game: “I have a hard time believing that there are many people doing basic research who aren't already familiar with NSF and its programs.”


    UC Balks at Campus-Wide Ban on Tobacco Money for Research

    1. David Grimm

    Concerned about academic freedom, the University of California (UC) has delayed voting on a plan to impose a blanket ban on research funding from tobacco companies. If approved, the ban would make UC the only U.S. university to forbid tobacco dollars campus-wide. Faculty members anguished over the issue for 4 years before calling on UC's governing body—the regents—to take a stand. Instead, the regents punted it back to the faculty last week.

    “It's a very good decision,” says James Enstrom, an epidemiologist at UC Los Angeles who uses Philip Morris money. “Academic freedom makes this a great university, and the faculty need time to consider this issue more thoroughly.” But Stanton Glantz, a bioengineer and antitobacco crusader at UC San Francisco, turns the argument around: “The tobacco industry funds research to confuse the public,” he says. “This manipulation of the scientific process subverts academic freedom and is antithetical to the fundamental mission of the university.”

    Faculty fission.

    Stanton Glantz (left) would like to see a blanket ban on tobacco funding at UC, but James Enstrom (right) says such a ban would violate academic freedom.


    Momentum for a UC-wide ban on tobacco funding has been building. Since 2003, seven units within the university system, including UC Berkeley's School of Public Health and the UC San Diego Cancer Center, have shut their doors to tobacco money. But UC's faculty-composed Academic Senate voided these bans in May 2005, declaring that only the regents had the authority to decline funding—and that they had to do it for the entire system or not at all.

    Currently, UC researchers can take money from any source, as long as terms of the grant do not violate university policy (for example, by excluding foreigners). As of last year, there were 19 active grants at UC supported by the tobacco industry, totaling $15.8 million. (UC's total grants and contracts added up to $4 billion that year.)

    Before the regents would consider a tobacco-funding ban, however, they asked the senate for input. That's when things got complicated. “The tobacco issue put our principles in conflict,” says senate member and UC Santa Cruz social psychologist Faye Crosby. “Most of us agreed that academic freedom trumps all other principles.” But then the senators reviewed documented evidence that the tobacco industry had manipulated researchers into publishing biased results—by tweaking manuscripts or threatening to cut off funding, Glantz charges. “We realized academic freedom can be illusory,” says Crosby. For many, allowing the university to accept tobacco money was allowing a threat to academic freedom.

    Enstrom disagrees. “I do not feel that any tobacco funding arrangements I've had have manipulated my academic freedom,” he says. In 2003, Enstrom published a study in the British Medical Journal that found no relation between secondhand smoke and lung cancer deaths. The project was partially funded by the Center for Indoor Air Research, which itself is funded by tobacco companies. Enstrom says the study was methodologically sound and that it added an important minority opinion to the smoking debate. “Thankfully, UC doesn't allow only certain points of view to be funded,” he says. “My entire career has been based on the academic freedom I've had.”

    The senate's recommendation to the regents reflected the divisiveness of the issue. On one hand, the faculty asserted that “grave issues of academic freedom would be raised” if the regents banned funding based solely on its source. On the other, they declared that academic freedom could be suppressed, and that the tobacco industry had a history of such suppression.

    The seemingly contradictory wording proved too much for the regents. At an 18 January meeting at UC San Francisco, the governing body appeared as divided as the senate. “I believe a yes vote [on this ban] would establish a very dangerous precedent which threatens our culture of academic freedom,” said Regent Jefferson Coombs at the meeting. “It would convey a signal that we do not trust our world-class faculty.” Regent Richard Blum countered that “none of us take academic freedom lightly, … but [accepting tobacco money] hurts academic freedom, not helps it.”

    In the end, the regents voted overwhelmingly to send the issue back to the faculty. An amendment charges the senate to clarify whether a blanket tobacco funding ban truly threatens academic freedom before the regents meet again in May.

    Michael Cummings, an authority on smoking issues who runs the Tobacco Control Program at the Roswell Park Cancer Institute in Buffalo, New York, says he's disappointed with the delay. “It's good to debate academic freedom,” he says, but “if you can't choose on this, you can't choose on anything.”


    With Change in the Seasons, Bird Flu Returns

    1. Dennis Normile,
    2. Martin Enserink

    An upsurge in H5N1 bird flu outbreaks in poultry across Asia is driving home the message that even countries that have eliminated the virus once shouldn't become complacent. The continuing high death toll in humans, including two recently detected cases of infection with a Tamiflu-resistant strain in Egypt, is also a grim reminder of how devastating the virus might be if it acquires the ability to spread easily among humans.

    Over the past 3 weeks, Thailand and Vietnam reported their first H5N1 outbreaks among poultry in 6 months. Japan, which seemed to have dodged the bullet since its cluster of outbreaks in 2004, confirmed that the virus hit one farm on 11 January and probably a second farm on the 23rd. South Korea, which last November suffered its first outbreak since containing the virus in 2004, reported that the virus had turned up on a fifth poultry farm. Several wild birds found dead in Hong Kong tested positive for H5N1. And Indonesia on 20 January reported its fifth human death from the virus in just 10 days, bringing its death toll to 62, by far the most of any country.

    High alert.

    Since H5N1 virus was detected in Japan this month, officials have been checking blood samples from poultry at neighboring farms.


    The increase in outbreaks in the Northern Hemisphere follows what has become an established pattern. The reason for the seasonality is still not well understood, says Les Sims, a veterinarian based in Manunda, Australia, who advises the U.N.'s Food and Agriculture Organization (FAO). It is likely to be some complex interaction among several factors, including cooler temperatures enabling the virus to survive longer in the environment, greater poultry trade in preparation for winter festivals, and movements of wild birds.

    The recurrence of the virus in South Korea and Japan is particularly notable. In both the winter of 2003-'04 and this year, outbreaks in South Korea were followed 4 to 6 weeks later by outbreaks in Japan. “The outbreaks in Japan and South Korea suggest to me free-flying birds as the most likely origin,” says Sims. Both countries are trying to determine how the virus was reintroduced.

    “The reasons for these failures need to be examined and the lessons applied elsewhere,” says Sims. But overall, he says the speed of the response, particularly in Thailand and Vietnam, “is a positive sign and shows that the surveillance systems are working.”

    In Indonesia, four of the five recent human deaths occurred in the Jakarta area. In response, the city government on 17 January ordered residents who keep backyard poultry to eat, sell, or cull their birds by the end of the month or have them confiscated and destroyed. The government is talking of gradually replacing the live markets that currently account for 80% of poultry sales in the city with slaughterhouses. “It would be a sea change culturally,” says John Weaver, senior adviser to FAO in Jakarta. If done properly, he says, eliminating backyard poultry could reduce the opportunity for the virus to survive in the environment. But he cautions against a sudden prohibition, which could lead smallholders to hide their fowl and refuse to cooperate with animal disease control efforts.

    Early this week, meanwhile, experts were poring over the puzzling and potentially worrisome details of a recent cluster of human H5N1 cases in Egypt. Late December, a 16-year-old girl and her 27-year-old uncle, living in the same house in Gharbiya province, both died of H5N1 infection. Sequence information made public on GenBank on 23 January by the U.S. Naval Medical Research Unit 3 (NAMRU-3) in Cairo shows that both were infected with a virus strain that is moderately resistant to the antiviral drug Tamiflu.

    Tamiflu resistance has been reported in a few other human H5N1 cases after patients were given the drug. However, the Egyptian samples showing resistance were taken just 2 days after Tamiflu treatment began, an unusually short period in which to develop resistance, says NAMRU-3 commanding officer Bruce Boynton. What's more, the virus in both patients had a rare resistance-conferring mutation, called N294S, seen only in one previous H5N1 patient in Vietnam.

    That's why Boynton says the evidence suggests “a more disturbing” theory: that both were infected by a sick bird that already harbored the mutated virus. If more such birds exist, doctors may see more H5N1 patients who don't respond well to Tamiflu. And if such a resistant strain were to spawn a pandemic, the world's vast Tamiflu stockpiles might be less helpful.

    Tests are currently under way to determine whether the patients had the resistant strain before they took the drug and whether virus from a third suspected H5N1 patient in the household, who also died, has the same mutation, Boynton says. Veterinary virologists are also checking to see whether the mutated virus can be found in birds in Egypt.


    Harvard Proposes One for the Team

    1. Jeffrey Mervis*
    1. With reporting by Constance Holden.

    Talk about greater collaboration across academic departments is cheap. But making it happen can be very expensive. Last week, Harvard University made a $50 million down payment on the concept, including seed money for a first-ever, university-wide department in developmental and regenerative biology. The move is part of a major expansion of the university's science and engineering programs, including a planned $500 million campus across the Charles River that was unveiled earlier this month.

    “There's a lot of life left in the disciplinary sciences, but at the same time, there is a trend toward concentration of resources and larger-scale collaborative science,” says Harvard Provost Steven Hyman, who last week announced the creation of a Harvard University Science and Engineering Committee (HUSEC). The committee, which will report to Harvard's president and its governing board, will use the $50 million to plan the new department—which will include stem cell research—and seed other initiatives, some of which could lead to similar new departments.

    All together.

    Steven Hyman will lead a Harvard panel fostering interdisciplinary science.


    Harvard professors have traditionally conducted their research and training within the confines of a particular school, be it the Faculty of Arts and Sciences (FAS), the medical school and affiliated hospitals, or the schools of public health and of engineering and applied sciences. Although some universities erased those lines decades ago, working across departmental boundaries at Harvard is “not unlike [working] with two entirely separate institutions,” says Douglas Melton, co-director of the Harvard Stem Cell Institute.

    Hyman will chair the university-wide committee, which he hopes will keep the 366-year-old institution among the leaders in all fields of science and engineering through the 21st century. And Hyman, rumored to be on the short list of Harvard presidential candidates, assumes that many of the committee's recommendations will cost money. “We expect [the committee] to propose a budget, and we know that a lot more will be needed,” he says. “But this shows the faculty that we are serious.”

    The new department will eventually have 25 to 30 faculty members, says Hyman—about half migrating from existing programs and the rest new appointments—and report to both FAS and medical school deans. It will serve as a focal point for the work of nearly 700 people, a cluster that Melton calls “one of the highest concentrations in the world of stem cell scientists.” Stem cell institute co-director David Scadden says the new department will be a “critical complement” to the activities of the institute, which will occupy space in the department's new building on the Allston campus, scheduled for completion in 2010. All the members of the new department will be part of the institute, which now has 45 principal faculty members.

    Nancy Andrews, dean of basic sciences at the medical school and a co-author of a report last summer that recommended the formation of HUSEC, calls the department “the obvious first choice” for interdisciplinary research because of the field's rapid growth.

    Hyman expects the new committee to have a detailed plan in place for the new department by 1 April. “They are keen to begin recruiting,” he notes. And he compares what Harvard is doing to the road map created a few years ago by National Institutes of Health Director Elias Zerhouni for more interdisciplinary programs across the agency's 27 institutes and centers. “That was his response to the changing world of science,” says Hyman. “And this is our response.”


    The Endangered Lab Chimp

    1. Jon Cohen

    A decline in the number of chimpanzees available for biomedical research in the U.S. has sparked a growing debate on the opportunities and costs of studies with our closest relatives

    Almost human.

    The U.S. has more than 1000 chimpanzees like this one at Yerkes that, owing to their similarities to us, are set aside for biomedical research.


    Fifteen years ago, the United States was one of a half-dozen countries that had captive chimpanzees available to biomedical researchers. Today, it stands alone. Every country except perhaps Gabon has abandoned this type of experimentation for a bramble of ethical, financial, scientific, and political reasons. Now the U.S. National Institutes of Health (NIH)—the main supporter of chimpanzees maintained for biomedical research—finds itself facing an incendiary debate over whether it should phase out such studies or breed more animals for future generations of investigators.

    The issue has become especially acute over the past few months, in the face of a new projection about the fate of the captive chimps set aside for biomedical research. For the past decade, NIH has imposed a moratorium on breeding any federally supported chimps, which are housed at six primate centers across the country. It enforces the ban by refusing to support any newborns. In 2000, the U.S. Congress also mandated that older “surplus” chimps no longer needed for research be moved from primate centers to retirement sanctuaries. As a result, the population has dropped from 1500 in 1996 to 1133 in October 2006. Now, many researchers who conduct biomedical research on chimpanzees are worried that the number of breeding animals is declining so rapidly that there will soon not be enough left to sustain the population. “The population is heading for a cliff,” says Todd Preuss, a neuroscientist at Yerkes National Primate Research Center in Atlanta, Georgia, which has the country's oldest colony of research chimpanzees. “If we don't start breeding these chimpanzees soon, they're going to go away, and they're going to be gone for good.”

    The push to breed more chimpanzees is forcing a reexamination of questions that have long surrounded research with our closest relatives, an endangered species that is rapidly disappearing in the wild. Where is the line that separates ethical from unethical research? What type of housing do chimps require? Where will the money come from to support the care of animals that routinely live 30 years in captivity and can live twice as long? Has NIH properly managed what it calls the “chimpanzee resource”? And why do scientists need chimpanzees for biomedical research anyway?

    On one end, the Humane Society of the United States and the New England Anti-Vivisection Society have launched campaigns to stop all “invasive” experiments with chimpanzees that might harm them and to have all the animals moved to sanctuaries. Some primate researchers, too, have misgivings about conducting the types of vaccine, drug, and pathogenesis studies that are done in the United States on chimpanzees. “If you talk to a lot of primate researchers, they're not comfortable with it,” says virologist Jonathan Allan, who conducts AIDS research with monkeys at the Southwest National Primate Research Center in San Antonio, Texas, one of the facilities that does biomedical chimp experiments. “You shouldn't be comfortable with it. You should have to search your soul as to the balance between the research and the good that comes from it and the bad part, which is what happens to the animals. It's a difficult place to be. If you're comfortable with it and you don't have any problem with it, that's a problem.”

    Then again, a growing number of researchers, such as Preuss at Yerkes, conduct so-called noninvasive biomedical studies in these chimpanzees that they say cause them no physical harm. Behavioral researchers—who are allowed to work at some zoos and sanctuaries—also study this population. “There's so much we can do without a destructive approach to captive chimps,” says Pascal Gagneux, a primatologist at the University of California, San Diego (UCSD), who conducts reproductive biology research with chimpanzee sperm samples. Gagneux, Preuss, and others contend that with new body-imaging technologies and the recent sequencing of the chimpanzee genome, the opportunities are greater than ever to use noninvasive techniques to learn about everything from human disease and aging to behavior and evolution.

    Still other researchers caution against making a blanket proclamation that invasive experiments with chimpanzees are unethical. “To draw a hypothetical line in the air I don't think does justice to the subtlety of these questions,” says Norman Letvin, an immunologist at the Beth Israel Deaconess Medical Center in Boston, who has done AIDS vaccine experiments in chimpanzees and monkeys. “These kinds of discussions need to be focused on very specific questions about a particular study.” Letvin no longer experiments on chimps and says he can't see any compelling reason today to use large numbers of them for biomedical research. But he stresses, as do many other investigators, that this animal model has led to “enormously valuable” medical advances in the past and may well in the future.

    Unfashionable model

    Scientists have conducted biomedical research on chimpanzees for more than a century. As many proponents of this animal model note, such research played a crucial role in the development of the vaccine for hepatitis B, a sometimes lethal virus that has infected 2 billion people. But scientists around the world have also performed studies that are now considered bizarre or brutal. The U.S. Air Force's chimponaut program shot them into space. Other researchers harvested their organs for human transplants, implanted electrodes into their brains to study sleep, and used them to gauge the effects of alcohol and marijuana. And a Soviet scientist attempted to inseminate them with human sperm to make a “humanzee.”

    NIH formally entered the chimpanzee research business in 1960, when Congress established a network of regional primate centers for basic and clinical research. Some of these great apes were bred in captivity, but many more were taken from Africa until 1973, when the United States signed the Convention on International Trade in Endangered Species of Wild Fauna and Flora, which barred the importation of wild chimpanzees. In 1986, faced with increasing demands for chimpanzees from researchers studying the emerging AIDS epidemic, NIH started a breeding program. Numbers quickly grew, with the initial 315 male and female breeders producing nearly 400 offspring by 1997.

    But the chimpanzee AIDS model had problems from the get-go. Researchers had to pay a steep user's fee, at least $50,000 per animal, and experiments often used so few animals that only the most pristine results would reach statistical significance. It also soon became clear that HIV typically doesn't cause disease in chimps, undermining the model's reliability. Once scientists discovered in 1987 that SIV, a simian cousin of HIV, caused an AIDS-like disease in rhesus macaques, that became the model of choice.

    In 1995, with few chimps being used to test AIDS vaccines, NIH's National Center for Research Resources (NCRR) established a moratorium on breeding the chimpanzees it supported “until further notice.” Although researchers continued to use chimpanzees to study vaccines for hepatitis C and respiratory syncytial virus, as well as treatments for other diseases, NCRR reasoned that the demand could be met with existing animals. In 1997, the National Research Council (NRC) essentially concurred, issuing a report, Chimpanzees in Research, that recommended extending the breeding moratorium until 2001. NRC's panel of experts cited “compelling” reasons for maintaining a population of about 1000 chimpanzees for research. But it concluded that the existing population was “more than adequate to meet research needs for at least five years.” It also expressly recommended that no facilities euthanize chimpanzees for population control.


    NCRR imposed the breeding and euthanasia bans and, as the NRC panel recommended, set up a Chimpanzee Management Program (ChiMP) to monitor the status of the population and promote the appropriate use of these animals in research. NCRR simultaneously established a working group of outside experts to advise ChiMP. The working group has recommended extending the breeding moratorium three times, most recently in May 2005. There was “a huge number of chimps that weren't being used” for research, says veterinarian William Morton, a member of the ChiMP working group who runs a primate consulting company, Paris NHP in Edmonds, Washington. “They were just sitting there.”

    With the publication of the first draft of the chimpanzee genome in September 2005, calls mounted for NCRR to lift the moratorium. In a commentary in that same issue of Nature, the heads of the U.S. primate centers again extolled the benefits of maintaining this “unique resource” and warned that if the moratorium were not lifted, the population would sharply decline within 5 years.

    Since then, one of the co-authors, John VandeBerg, director of Southwest National Primate Research Center, has performed a more detailed analysis of the age and health status of the chimps housed at all six facilities. At a chimp meeting at Yerkes in October 2006, VandeBerg said that of the 1133 animals then available, just 200 females were potential breeders. If the breeding moratorium were not lifted, he added, there will be no research chimps left by 2037, when all of these chimpanzees will have died (see graph, above).

    VandeBerg concedes that his model is “simplistic”—for instance, it doesn't take into account the fact that some facilities, at their own expense, have bred a few chimpanzees despite the moratorium. Even so, his bleak projections startled many at the meeting, including Ajit Varki, a glycobiologist at UCSD who helped lead the drive to sequence the chimpanzee genome. “What's happening now is really a disaster,” says Varki. Others noted that the aging of the population is already limiting brain and behavioral research that depends on younger animals.

    Yerkes head Stuart Zola, who is a member of the ChiMP working group and the broader NCRR advisory council, emphasizes that many of these “potential breeders” may not become pregnant or may not take care of offspring if they do. “It's almost too late unless there's substantial breeding initiated quickly,” says Zola.

    Although Zola is not one of them, several researchers fault NCRR for the way it has managed the chimpanzee resource. “Most of what they do is fund mass spectrometers and clinical research centers,” says Varki, who would like the breeding moratorium lifted. “I think the chimpanzees are a thorn in their side.” Even Morton, who supports the moratorium, criticizes NCRR for its failure to hold regular meetings of the working group he sits on, or to follow its advice and develop a financial and management plan for the population. “Somebody needs to grasp this thing and show some leadership at NCRR,” says Morton, who previously ran the NCRR-funded primate center at the University of Washington, Seattle. “What are the issues, and what are the facts?”


    Using MRI, Emory University's James Rilling does comparative analyses of chimp (left) and human brains to study aging and evolution.


    John Harding, who heads primate resources for NCRR, would not explicitly address why no long-term plan exists. But Harding stresses that the institution works closely with the primate centers and has “active policies and processes to manage and oversee its chimpanzee resource program.” NCRR plans to convene its working group in March to reassess the moratorium, which is in effect until December 2007.

    Ethical lines

    Should NCRR lift the moratorium, debate will likely intensify over what type of chimp research is ethically acceptable and worth the expense—especially now that almost everyone else has gotten out of the business.

    The Netherlands, the last European country to conduct invasive research on chimpanzees, outlawed the practice as of 2004 and has been moving its colony of more than 100 animals to zoos and safari parks. In October 2006, the one Japanese pharmaceutical company still conducting invasive research in that country decided to stop; with support from Kyoto University, the company plans to open a retirement sanctuary for its 80 animals in April. The Hepatitis Research Foundation in Poughkeepsie, New York, which has long conducted biomedical research at a chimpanzee colony in Liberia, decided last fall to release the last of its 74 animals onto island sanctuaries. Gabon's Centre International de Recherches Médicales in Franceville has done biomedical research on its small population of captive chimps in the past, but future plans are unclear.

    Morton says he'd like to see the United States phase out biomedical research with chimpanzees, too. “It settles on the side of people who have ethical arguments, but for financial reasons,” says Morton. “If you lift the moratorium, there's going to be breeding like crazy, and once again we'll have all these chimps and who'll be supporting them?”

    In fiscal year 2005, NCRR spent $8.7 million on chimpanzee care. More than 20% of that went to Chimp Haven in Keithville, Louisiana, the country's only publicly funded sanctuary for the retirement of surplus chimpanzees, and that amount is certain to rise as more animals are retired. Primatologist Linda Brent, who heads Chimp Haven, which depends on both public and private funding, questions how the federal government could possibly afford to breed more chimpanzees. The estimated lifetime cost of caring for a chimpanzee—captive males live for 30 years on average, females for 45—ranges from $300,000 to $500,000, she notes.

    If the U.S. government does decide to invest more money in maintaining the research chimp population, many investigators contend that it should rethink what types of experiments can be done and how the animals are housed. “Chimpanzees should not be used as furry test tubes,” says Beatrice Hahn, a virologist at the University of Alabama, Birmingham, who hunts for AIDS viruses in feces collected from wild chimpanzees. Hahn, who conducts no invasive research, contends that “95% of the experiments done with them are not necessary.”

    In their 2005 Nature commentary, VandeBerg and co-authors argued that chimpanzees should remain available for disease research and for testing drugs and vaccines. VandeBerg notes that some proprietary experiments with monoclonal antibodies done for commercial companies have led to illness or even death of chimps—preventing harmful drugs from entering human trials. “It's unethical from a human standpoint to not do this research,” he says.

    In an opposing commentary in the same issue, UCSD's Varki, Gagneux, and primatologist James J. Moore argue that chimpanzees should be used only in experiments that could also be done ethically in humans. That would rule out vaccine studies that intentionally infect animals with potentially harmful viruses, for instance. Even with such constraints, they predict demand for animals to rise. “I suspect in 5 to 10 years from now, there's going to be much greater interest in studying chimps in nondangerous ways,” says Varki. If these chimps die off, he says, “history will look back and say how could you let that happen.” In their commentary, they also called for increasing funding to provide chimpanzees with “optimal living conditions,” such as Chimp Haven's facility, where chimps can socialize outdoors for much of the day.

    Just how many chimpanzees the country needs to maintain a viable breeding population remains a hot-button issue. Nate Flesness, executive director of the International Species Information System and a member of the 1997 NRC committee, notes that North American zoos have fewer than 350 chimpanzees that they share for breeding. Flesness and others say the U.S. government should simply support a core breeding group of chimpanzees for biomedical research as an insurance policy for future emergencies. Beth Israel's Letvin agrees with this minimalist strategy. “If we've learned anything over the years, it's that we don't know what the next epidemic will be and what the next major health crisis is going to be,” says Letvin. “It would be foolhardy to take any potential animal model off the table.”


    Feared Quagga Mussel Turns Up in Western United States

    1. Erik Stokstad

    Scientists are trying to assess the potential for ecological and economic damage after finding a relative of the infamous zebra mussel in the Colorado River

    For 2 decades, the zebra mussel has tormented the Great Lakes. Along with its close cousin, the quagga mussel, the fantastically prolific mussels have clogged the intake pipes of power plants, coated the hulls of boats, and thrown ecosystems out of whack. Western states have been so concerned that in 1998, they started a major campaign, called the 100th Meridian Initiative, designed to prevent boaters from accidentally transporting the mussels or other exotic species to their waters.

    Now the initiative has suffered a major defeat. Earlier this month, quagga mussels were found in Lake Mead, a 50,000-hectare reservoir in Nevada. And last week, they were confirmed downstream in the Colorado River. There's no sign of zebra mussels yet, but observers fear their arrival is only a matter of time. State officials in Nevada and California are convening scientific advisory panels to figure out what to expect and how to cope with the quagga. “This is an organism that would be devastating for California's aquatic ecosystems and for freshwater infrastructure,” says Richard Soehren, water policy adviser for the California Department of Water Resources.


    Both zebra (Dreissena polymorpha) and quagga (D. bugensis) mussels are native to Eastern Europe. They are thought to have arrived in the Great Lakes by the late 1980s via the ballast water of container ships. In some places, up to 700,000 zebra mussels crowd together in a single square meter. By clogging intake pipes, the mussels cost the power industry many millions of dollars in added maintenance. Inexorably, the mussels have spread down the Mississippi River and throughout much of the eastern United States.

    As a popular destination for boaters from across the country, Lake Mead was clearly in the mussels' path, and officials there have been on the alert after several close calls. In 2004, for example, they found dead zebra mussels on a half-dozen houseboats arriving at Lake Mead, 1800 kilometers from the most westerly sighting of zebra mussels.

    Now it's clear that the quagga mussel already beat the zebra across the Great Divide. On 6 January, a diver doing a routine inspection of a breakwater found a quagga mussel at a Lake Mead marina, a few kilometers upstream from Hoover Dam. “I was heartbroken,” says Wen Baldwin, president of the Lake Mead Boat Owners Association, after the diver showed it to him. Since then, divers with the National Park Service (NPS), which runs the Lake Mead National Recreation Area, have found mussels in four more locations. Based on the size of the mussels sent to him for identification, Robert McMahon of the University of Texas, Arlington, estimates that they have been in the lake for at least 2 years. The deep, cool water and rocky bottom offer an ideal habitat for the quagga mussels, notes Charles Ramcharan, a limnologist at Laurentian University in Sudbury, Canada. “Lake Mead is going to have a huge infestation,” he predicts.

    Officials are worried about the impact on Hoover Dam, which last year generated 3.3 billion kilowatt-hours of electricity, and on the two drinking-water plants that also draw water from Lake Mead. Another big concern is the potential effect on sport fisheries in the lake. The mussels filter huge volumes of water, removing phytoplankton and boosting nutrients. This seems to have harmed commercial fish stocks in some but not all of the Great Lakes.

    An emergency task force of NPS and state agencies in California and Nevada is scrambling to prevent further spread. As a temporary measure, Park Service boats have been grounded and concessionaires have been told not to transport rental boats. They have ramped up inspections of private boats at the lake as well. California is trying to increase boat inspections at its three border stations that receive traffic from Lake Mead. Ann Malcolm, general counsel for the state's Department of Fish and Game, says the agency will ask the legislature for the authority to inspect any possible sources of water on boats and force owners to drain them.

    But the mussel seems to have already spread downstream. On 17 January, divers with the Metropolitan Water District (MWD) of Southern California found quagga mussels in Lake Havasu, near the intake to the Colorado River Aqueduct, which supplies water to 18 million people. “We are going to be taking aggressive action,” says Debra Man, MWD's chief operating officer. They plan to use chlorine or copper sulfate to kill any mussels or larvae in the 386-km-long canal. Luckily, quagga mussels prefer deeper, cooler water with relatively few nutrients, so they probably won't thrive in the canals, says Ed Mills, an ecologist at the Cornell Biological Field Station in Bridgeport, New York.

    However, if zebra mussels arrive as well, the situation could be worse. Not only might zebra mussels flourish in the aqueduct, but they could also cause serious problems with the many ditches and pipes in the Imperial Irrigation District, which takes its water from the Colorado River. “It's conceivable those canals could require extensive maintenance,” says Michael Mizumoto, the district's biological control unit supervisor.

    For the moment, however, scientists and managers will have enough headaches with the unfolding western drama of the quagga mussel. Says Ramcharan: “Y'all just bought front-seat tickets to the invasion show.”


    Three-Headed Quasar Promises to Shed Light on Universe's Past

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


    Triple plays are rare in baseball, but not as rare as triplet formations of quasars in space. In fact, images depicting multiple quasars in close proximity have always been routinely interpreted as mirages, different views of a single real quasar.

    But not always. Of roughly 100,000 known quasars—cosmic beacons that beam luminous radiation across the universe—about 100 have been identified as being pairs. Quasars are powered by massive black holes in the cores of galaxies, and when two such galaxies collide, their central black-hole quasars retain their separate identities, so pairs can survive at least for a while.

    Collision of a third quasar with such a doublet would be an extremely rare event, but astronomers say they have now witnessed the birth of quasar triplets.

    “We have found the first case of a physical triple-quasar system,” said astronomer George Djorgovski of the California Institute of Technology (Caltech) in Pasadena, leader of an international team reporting the discovery at the meeting. Two of the quasars in the group, designated QQQ 1432-0106, were discovered before 1989. Astronomers originally believed that the pair was an illusion created by gravitational lensing of a single quasar. Such lensing, an effect of Einstein's general theory of relativity, occurs when an intervening mass's gravity bends the light arriving from distant objects. In many known cases, such lensing bends the light from a distant quasar so much that it appears to arrive at Earth from multiple pathways, creating the impression of more than one object.

    Real deal.

    Rare triple quasar at center of image was thought to be an optical illusion.


    Later observations of that quasar system questioned the mirage interpretation, however. Many astronomers concluded that it consisted of two distinct nearby quasars at a redshift of 2.1, corresponding to a time when the universe was about 3 billion years old.

    More recently, astronomers from Caltech and the École Polytechnique Fédérale de Lausanne in Switzerland, using data from the Keck Telescope in Hawaii, spotted evidence for a third nearby quasar, fainter than the others but also at about the same redshift distance. Further observations with the European Southern Observatory's Very Large Telescope in Chile confirmed the Keck finding.

    Efforts to explain the triplet as a gravitational-lensing effect have failed, Djorgovski said, as have efforts to find any intervening massive body that could have acted as a lens. And scrutiny of the colors of light emitted by the quasars revealed subtle differences, further suggesting that the three quasars are distinct. “This is almost certainly not a gravitational lens,” Djorgovski said, “so we are left with the alternative explanation that it is a physical triple-quasar system.”

    Although such systems should be rare, they are not entirely surprising, and their existence could aid efforts to understand the dynamics of galaxy mergers in the early universe. Light from the triplets departed on its journey to Earth more than 10 billion years ago, at a time when galaxies occupied a smaller universe and crowding led to frequent collisions.

    “These interactions are in fact quite common,” said Frederic Rasio of Northwestern University in Evanston, Illinois. In fact, his computer simulations show that galaxies would often collide and merge to form larger galaxies, and when two galaxies containing central black hole-powered quasars merged, the two black holes would begin orbiting each other similarly to a binary star system.

    Eventually, such orbiting black holes will swirl closer together and collapse into each other. Before that happens, however, another colliding galaxy could bring a third black hole to the dance, at which point the interactions get more complicated, Rasio's simulations show. “The three black holes interact rather violently and unpredictably,” Rasio said. “What happens at the end … is these black holes basically kick themselves out of the center of that galaxy.”

    Their rapid exit occurs after the latecomer black hole pairs up with one of the original two, giving the remaining loser a gravitational kick that hurls it out of the galaxy. The new pair recoils in the opposite direction. In both cases, the black holes depart their parent galaxies at speeds reaching thousands or even tens of thousands of kilometers per second.

    “These speeds are high enough that the black holes recoil certainly out into the halos of the galaxies and sometimes can even be kicked all the way out, … meaning they become wandering black holes that go through empty intergalactic space,” Rasio said.

    In the observed triplet quasar system, the black holes have just begun to come together to perform their partner-swapping dance; they are still about 100,000 light-years apart. The entire process of merging and eventual splitting up will take about 100 million years, Rasio's simulations indicate.

    “The process that Dr. Rasio has modeled is very, very far in the future,” said astronomer Virginia Trimble of the University of California, Irvine. “So in some sense, the prediction has been verified by the observation, and the observation has been explained by the theory.” But 100 million years is a long time to wait to see whether the future behavior of the triplet really matches the theoretical forecast.

    Evidence that such triplet interactions occur could come sooner, however. A recoiled pair of black holes would soon merge and generate gravitational waves that might be detectable, Rasio said. And there also exists the possibility of detecting a wandering black hole speeding through space, ideally not heading too close to Earth.


    Middle-Earth Denizens Mob the Milky Way

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


    The mystery of the missing dwarf galaxies may have been solved. Instead of looking for dwarfs, astronomers should have been searching for hobbits.

    Researchers from the Sloan Digital Sky Survey reported the discovery of seven previously unknown dwarf galaxies surrounding the Milky Way, plus an eighth at the edge of the Milky Way's gravitational influence. Because those small galaxies were found in a survey of only one-fifth of the sky, dozens more are likely to exist, team member Daniel Zucker of the University of Cambridge, U.K., said at the meeting.

    Computer simulations based on current theories of galaxy formation suggest that large galaxies such as the Milky Way should be surrounded by dozens or even hundreds of dwarf satellites. Until recently, however, only a few such satellites were known.

    A possible explanation for the discrepancy, supported by the Sloan results, is that many of the dwarfs are too dim to be easily detected. “These new dwarfs are extremely faint,” Zucker said. “We're finding lots of them, and they seem to be much fainter than anyone suspected galaxies could be before. So perhaps rather than dwarf galaxies, we should give them the name ‘hobbit galaxies.’”

    Fecund “hobbit.”

    Leo T (central white cluster) is the smallest known star-forming galaxy.


    The eighth of the new galaxies, designated Leo T, is stranger still. At a distance of 1.4 million light-years, it is probably not a Milky Way satellite but rather a free-floating dwarf within the Local Group of galaxies, Zucker said.

    Leo T contains both old and new stars, generating a total brightness only about 50,000 times that of the sun. The presence of new stars is surprising, because most other dwarfs ceased star formation long ago.

    “This is basically the smallest, faintest star-forming galaxy known,” Zucker said. “The Local Group could be filled with faint objects like this.”

    More such dim, free-floating galaxies could help explain the lack of dwarfs in past observations, said Nitya Kallivayalil of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts.

    “This missing-satellites problem is really one of the great mysteries,” she said. “The point that there could be free-floating satellites bound to the Local Group but not necessarily to any major member of the Local Group is very interesting, and it's something that is not outlandish when you look at the simulations.”


    Snapshots From the Meeting

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


    Sic transit.

    The Large Magellanic Cloud looks set to outrace our galaxy's gravity.


    Caught speeding.Long believed to be the Milky Way's most prominent satellite galaxies, the Magellanic Clouds may turn out to be mere passers-by. Rather than pursuing a leisurely orbit, both the Large and Small Magellanic clouds appear to be speeding by at more than 300 kilometers per second, possibly fast enough for them to escape our galaxy's gravity. “We do have to now consider the possibility that the clouds are perhaps unbound to the Milky Way,” said Nitya Kallivayalil of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts. Kallivayalil and two other astronomers calculated the clouds' velocities by using data from the Hubble Space Telescope to compare the clouds' motion across the sky to that of very distant (and hence effectively stationary) quasars. The Milky Way could still keep the clouds in orbit, Kallivayalil said, if it is twice as massive as current estimates suggest or if its invisible halo of dark matter has an odd shape.

    Supernova solution. The space-based Chandra X-ray Observatory has helped clear up a long-standing mystery about a famous supernova. Spotted by Johannes Kepler in 1604, the supernova has seemed likely to be Type Ia, a thermonuclear explosion detonated when a white dwarf star accumulates too much mass to remain stable. Yet surrounding the explosion site was circumstellar material more commonly seen with Type II supernovae, which occur after a massive star burns out, collapses, and explodes. X-rays from the 1604 supernova remnant, recorded by Chandra, clinch the case for Type Ia, astronomer Stephen Reynolds of North Carolina State University in Raleigh reported at the meeting. The x-rays reveal large amounts of iron, a telltale sign of a thermonuclear blast. Type II supernovae remains contain more oxygen than iron. “There's iron everywhere; oxygen is hard to find” around the blast, Reynolds said. “But at the same time, we've confirmed the presence of circumstellar material.” That material, Reynolds said, suggests that Kepler's supernova might belong to a new class of Type Ia supernovae from a slightly-more-massive-than-average progenitor.

    Mapping the darkness. Using almost 1000 hours of observing time with the Hubble Space Telescope, astronomers have produced the highest-resolution map yet of dark matter's distribution in the cosmos. “It's the largest project that has ever been done with the space telescope,” said Nick Scoville of the California Institute of Technology (Caltech) in Pasadena, principal investigator of the NASA project. Known as COSMOS (for Cosmic Evolution Survey), the project traced the location of dark-matter across a wide patch of the sky (nine times the area covered by the moon) at various distances out to a depth corresponding to a time when the universe was about half its present age. The dark matter, unknown material that gives off no visible light, was detected by the way its gravity blurred the shapes of faraway galaxies. The new maps, published last week in Nature, show that dark matter provides a massive scaffolding around which the universe's ordinary (or “baryonic”) matter conglomerates in clusters of galaxies. “Without this dark matter, … the universe wouldn't exist as it is today,” said COSMOS collaborator Richard Massey, also of Caltech. There are hints, however, that ordinary matter does not always coincide with the dark-matter skeleton. “There are some interesting discrepancies within the map,” said Massey. Previous darkmatter mapping by Anthony Tyson of the University of California, Davis, and colleagues showed similar discrepancies. “There is something funny going on,” said Tyson, who is not involved in the COSMOS project.


    Loopy Lens Proteins Provide Squid With Excellent Eyesight

    1. Elizabeth Pennisi


    Near-perfect eyes.

    Vampire squid lenses are designed for seeing details, even in virtual darkness.


    When Alison Sweeney wanted to learn about eye evolution, she went to sea. While the ship rolled beneath her, she dissected the eyes of squid freshly retrieved from 1000 meters below and tested how well each lens resolved the details of a panel of ever-narrower black and white stripes. Back at Duke University in Durham, North Carolina, as a graduate student in the lab of Sönke Johnsen, she combined those results with biochemical and modeling data on the optical and chemical properties of lens proteins to reconstruct the history of vision in cephalopods—squid, octopi, and their relatives. From just one ancestral lens protein—vertebrates started with several—these marine invertebrates have evolved lens-based eyesight more than once, Sweeney reported at the meeting.

    The work “is one of the first times that people have dissected the origins of the complexity in the lens” used by many underwater creatures, says evolutionary biologist Todd Oakley of the University of California, Santa Barbara. Seeing clearly underwater requires a special spherical lens with a high refractive index in the center but a lower index toward the edge. This gradation is achieved with progressively lower concentrations, from the lens's center outward, of proteins called crystallins.

    The genes for crystallins evolved from the duplicated genes of small enzymes often involved in stress responses. Vertebrates have multiple families of crystallins, but cephalopods have just one family, the S-crystallins, which descend from a liver enzyme.

    To study this simpler protein family, Sweeney divided the squid lens into four concentric layers and analyzed its protein makeup using mass spectrometry and other techniques. With the help of Duke's David Des Marais and Yih-En Andrew Ban, she figured out evolutionary relationships among that squid's crystallins and determined how the proteins fold and interact. She and Mikhail Matz of the University of Florida, Gainesville, also sequenced 600 genes for S-crystallins from a dozen other cephalopod species. “It's the breadth of approach that I am most impressed with,” says Thomas Wolcott, a physiological ecologist at North Carolina State University in Raleigh.

    Researchers already knew that S-crystallins have an extra loop compared to the ancestral liver enzyme. Early on in evolution, this loop was short. But in newer S-crystallin variants, it is longer, and the proteins are more positively charged, Sweeney reported. The older, shorter proteins were evenly distributed throughout the cephalopod lens. But there was a gradient for the more recent crystallins, with almost none in the center and relatively more near the edge. (Amounts dropped at the edge itself.) Sweeney's analysis suggested that there had been positive selection for the longer loops in the younger proteins.

    For a lens to be transparent, crystallins must stay folded and evenly dispersed to create a glassy state. That's not a problem in the closed-packed proteins of a lens's center. But in the outer half of the lens, proteins can have the freedom to form clumps and cause cataracts. It could be that the longer loop helps prevent this by further stabilizing the protein, Sweeney noted. In addition, the high positive charge helps keep the proteins apart. “It's amazing how finely tuned the squid lens is to do its job,” says Jonathan Henry, a developmental biologist at the University of Illinois, Urbana-Champaign.

    When Sweeney sequenced the S-crystallin genes from various cephalopods, she expected to find that all these lens proteins had descended from a common cephalopod ancestor that had co-opted the liver enzyme. Instead, the sequences indicated that this adaptation of the enzyme into lens proteins occurred later, after the ancestral cephalopod had begun to diverge into squid, octopi, and other species. How many cephalopod lineages independently came up with this solution remains unclear, but “it looks like there's been novel evolution [of the enzyme] at least twice,” she reported.

    After her study, Sweeney is deeply impressed by cephalopod vision. Indeed, she noted, the shipboard tests showed that the vampire squid's lens, which appeared early in the evolutionary history of cephalopods, “has a visual acuity better than in a state-of-the-art Zeiss dissecting microscope.”


    Muscle Fibers Shift Into High Gear

    1. Elizabeth Pennisi


    One look at a ballerina as she pirouettes and poses drives home the remarkable ability of our muscles to adapt to diverse biomechanical demands. Manny Azizi and Thomas Roberts, biomechanists at Brown University, have now found that as certain muscles contract, they vary their shape to balance the need for speed and force. It's as if these muscles have a builtin automatic transmission, says Azizi.

    “Their study hellip; takes us one step closer to understanding how skeletal muscle works in active animals,” says David Carrier, a comparative physiologist at the University of Utah, Salt Lake City. The data could even inspire better robots. “Their results may provide a simple means for automatically varying the gearing of a robotic [muscle] with changes in load,” says William Kier of the University of North Carolina, Chapel Hill.

    The body has several kinds of muscles, each characterized by a particular alignment of individual fibers. Biceps have parallel fibers and excel as fast contracters, for example. In contrast, calf muscles are pinnate, with short fibers arranged at an angle to the direction of contraction. This configuration packs in more fibers per square centimeter, making the muscle stronger, but sacrifices contractile speed.

    To build a computer model of how pinnate muscles behave under different demands, Azizi initially turned to programs for designing video games, which also require three-dimensional animation. His virtual muscle could contract, shortening along the vertical dimension—that is, its height—and expand along other dimensions to maintain a constant volume. For each new muscle shape, Azizi observed whether, and to what degree, the fibers changed their angle.

    The simulations showed that certain muscle shapes caused contracting pinnate fibers to shift to a less steep angle. When that happens, the muscle's overall height decreases more than it would have had the fibers maintained their angle. In other words, the virtual muscle shifted into the equivalent of a high gear ratio, increasing the speed of contraction. Other simulations indicated that pinnate muscles with unchanging angles were the strongest.

    Azizi then looked at whether real muscles acted this way. He had expected that each pinnate muscle would have just one gear ratio, that is, undergo a characteristic shape change, and therefore be strong or contract fast but not have both features.

    When he and Roberts evaluated how the drumstick muscle of turkeys shortened under different conditions, the results surprised Azizi. “A single muscle undergoes not one shape change but a range of different shape changes under different circumstances,” he said.

    Paralleling the virtual muscle, the turkey fibers themselves shortened about the same amount under the various test conditions. But the overall muscle contracted more under lighter forces, kicking into a high gear. With a heavy load, the angle of the fibers remained constant, and the muscle contracted only a little and instead became more oval, just as in the simulations. In this way, the muscle operated at a lower gear and took full advantage of the dense packing of pinnate fibers, Azizi noted.

    Fast and strong.

    Most of the hamstring muscles have parallel fibers (diagram, left), whereas those in the calf are pinnate (right).


    Just as one changes gears on a bicycle to crawl up an ever-steeper hill, “the direction of change in the muscle gears matches the mechanical demands of contraction,” Azizi said. Moreover, the muscle's shifting of gears required no nervous system input, occurring automatically depending on the load applied.

    Azizi proposes that although pinnate muscle fibers often rotate as they contract, heavy loads pull against the fibers too much for them to do that. Thus, although pinnate muscles are supposedly specialized for force, under light demand, they can also work fast. The study is “outstanding and very important for assessing muscle architecture with relation to function,” says Andrew Biewener, a biomechanist at Harvard University. “It's something that many of us have thought about but never worked or thought through.”


    Whale Worm Sperm Factories

    1. Elizabeth Pennisi


    Five years ago, researchers were thrilled by a decomposing whale carcass they found on the floor of California's Monterey Canyon, 2900 meters underwater. The carcass was home to a thriving community of bacteria-filled tubeworms, called Osedax, embedded in its decaying bones. The visible worms were all females, each attended by up to 100 microscopic males that live in the female's gelatinous tube (Science, 30 July 2004, p. 668). Now, biologists have taken a closer look at these dwarf males and found that they have a distinctly odd but highly targeted development: They fail to mature, except with respect to their ability to produce sperm.

    Since 2002, Robert Vrijenhoek and his colleagues at the Monterey Bay Aquarium Research Institute in Moss Landing, California, have visited several more whale falls, some of which are less than 1000 meters deep. At the meeting, marine biologist Greg Rouse of Scripps Institution of Oceanography in San Diego, California, reported finding at least nine Osedax worm species on these carcasses. “They are finding new species every time they go down,” says Mark Martindale, an experimental embryologist at the University of Hawaii, Honolulu.

    Rouse has also brought worm-covered whale bones back to the lab, where he used electron and confocal laser scanning microscopy to detail the males' anatomy. In his earlier studies, Rouse noticed that the male Osedax worms look like larvae of tubeworms typically seen at deep-ocean vents. But the new work shows them to be even less well-developed than these larvae.

    Mini males.

    White, larvalike males use hooks to attach to the pinkish, gelatinous tube of a female worm living on decaying whale bones.


    The dwarf males have no mouth, no anus, and no gut at all. There's no circulatory system, nor any of the internal stores of bacteria that females depend on for nourishment, he reported. Smaller males have lots of yolk from the egg from which they were born, and larger males have almost none, suggesting that males deplete this resource as they grow.

    Instead of internal organs, sperm at different stages of development stuff the male worm's body cavity. Rouse discovered a unique sperm duct that opens out at the top of the male's head. His studies indicate that sperm precursor cells start out at the worm's head, migrate toward the “tail,” and finally move forward again before being released.

    Rouse had previously suggested that as females age, they accumulate a harem of males. New data based on worms collected during recent underwater expeditions buttress this view. The work suggests that immature worms that land on bone become female, whereas those that settle on existing female tubes become males—a pattern known in at least one other annelid, Rouse pointed out.

    The analysis of the male whale worm is exciting, says marine biologist Kenneth Halanych of Auburn University in Alabama: “It reminds us that there are still many interesting discoveries that await [us] in the oceans' depths.”