News this Week

Science  05 Nov 2010:
Vol. 330, Issue 6005, pp. 738
  1. Infectious Diseases

    Haiti's Outbreak Is Latest in Cholera's New Global Assault

    1. Martin Enserink

    Was it imported or indigenous?

    That was one of the first questions cholera scientists were asking after a deadly surprise outbreak of cholera began in Haiti 2 weeks ago. Angry Haitian protesters had already decided: They held peacekeepers from Nepal—a country where the disease is endemic—responsible for bringing Vibrio cholerae to their already ravaged country and demanded their departure. But some scientists pointed out that although Haiti had never reported the disease before, V. cholerae is ubiquitous in aquatic environments; given the right circumstances, its numbers can swell dramatically and trigger an outbreak.

    On Monday, the U.S. Centers for Disease Control and Prevention (CDC) rendered its verdict: DNA fingerprinting of the microbes from 13 patients had shown that it was most similar to strains from South Asia, according to a press release, suggesting that that's where the disease was imported from. (The carefully worded statement did not mention Nepal.)

    Out of control.

    During recent cholera outbreaks in Africa, the mortality rate far exceeded the international target of 1% or less.


    For cholera experts, it was a familiar debate that often takes place when cholera pops up in a new locale. “People always assume cholera had to come from somewhere else. It's usually local, ” contends Rita Colwell, a veteran cholera scientist and former head of the U.S. National Science Foundation, who had put her money confidently on the environmental route.

    Cholera experts agree on one thing, however: The outbreak is another coup for El Tor, the cholera biotype that emerged over half a century ago and has since slowly spread across the globe in what researchers say is cholera's seventh recorded pandemic. Recently, El Tor—“a pretty nasty beast,” according to molecular biologist John Mekalanos of Harvard Medical School in Boston—has also been wildly successful in Africa, where the disease has gone from sporadic to increasingly entrenched in just the past decade. An epidemic raging in Nigeria this year, which so far has not grabbed international headlines, has already killed more than 1500 people, and at least 550 lives have so far been lost in neighboring Cameroon. In 2008–09, Zimbabwe had a massive epidemic that killed over 4000 people.

    El Tor appears to cause longer-lasting outbreaks than its predecessor, simply named “classical, ” and to survive longer in the environment. That could be bad news for Haiti. A preliminary study by CDC suggests the outbreak could last years and cause as many as 100, 000 cases.

    Few saw it coming. After the 12 January earthquake, which killed an estimated 230,000 Haitians and left more than a million homeless and living in squalid camps, health officials were worried about a panoply of diseases, including dysentery, malaria, and dengue. An international effort was launched to help the country beef up surveillance and equip the National Public Health Laboratory in Port-au-Prince for diagnostic testing.

    Although cholera wasn't on the radar screen, the effort has proven useful during the outbreak, says Eric Mintz, a CDC epidemiologist specializing in waterborne diseases: The Port-au-Prince lab fingered V. cholerae just 4 days after the first suspected case surfaced. CDC's labs in Atlanta confirmed the diagnosis and typed the bug. (It belongs to the strain O1, like most cholera around the world, and a serotype called Ogawa.)

    V. cholerae is normally present in coastal waters worldwide, even in countries where the disease is absent. It loves brackish water and can occur in rivers and lakes as well. Clinging to zooplankton—in particular, to tiny crustaceans called copepods—the bacteria can hang around indefinitely in relatively low numbers. There's no question that outbreaks can kick off when a series of environmental factors—including rising water temperatures, alkalinity, and high nutrient levels—conspire to cause zooplankton blooms, offering the cholera microbe a chance to proliferate as well. People become sick when they ingest the water and spread the disease when traces of their feces end up in other people's drinking water.

    But there's debate about how often this scenario plays out. When Peru was hit by cholera in 1991, the start of a massive outbreak in Latin America that killed almost 9000, there were suspicions that the microbe had been introduced by one or more ships, presumably from Asia. But Colwell's studies suggested that the bug came from Peru's coastal waters as a result of conditions caused by El Niño. “Based on 40 years of research,” Colwell says she believes something similar happened in Haiti. She is “not convinced” by the CDC statement because the agency used a technique called pulsed-field gel electrophoresis that doesn't yield a very detailed fingerprint. Colwell says she'd like to study water samples from Haiti herself but has been unable to obtain them.

    But Mekalanos says the case for an environmental outbreak in Peru was never quite clinched and that Colwell and others may have dismissed the Nepalese connection in Haiti too soon. The fact that the troops were based along a tributary to the Artibonite River, where some of the first cases were found, and left home during a cholera outbreak “was a bit of a smoking gun,” says Mekalanos, who is eager to do some molecular sleuthing of his own. Any infected soldiers would presumably have been asymptomatic, he says; 75% of those infected with El Tor are. (Of course, there are other potential routes through which a South Asian strain could have arrived in Haiti, he adds.)

    Over the past 5 decades, El Tor has almost entirely replaced the classical biotype that scientists assume had reigned for centuries. Why it has done so is the topic of much speculation but few hard facts. One theory, says Mekalanos, is that the classical biotype was more adapted to reproducing in humans—and it had ample opportunity to do so until well into the 20th century. But as sanitation and drinking water started improving around the world, a strain that is hardier and better at staying alive in the environment may have gained an edge.

    New threat.

    A woman takes care of a cholera patient at a hospital in the Artibonite Province in Haiti.


    What's next for Haiti? Mintz and his colleagues have tried to predict the Haitian outbreak's course by extrapolating from the Latin American one, which spared the islands of the Caribbean. Like Haiti now, the population had little or no immunity at the time, not having seen the disease for decades. Not surprisingly, the scope of the outbreak in each country strongly correlated with basic indicators of socioeconomic development such as infant mortality, literacy, and GDP, says Mintz. In terms of development, Haiti is roughly where Bolivia was in the early 1990s, and models suggest that Haiti could face some 100, 000 cases over the next couple of years, he says. “It's both extensive spread and possible persistence that we are concerned about, ” he says.

    The key weapon is to prevent transmission where possible, with clean water, sanitation, and education, and to rush treatment to those affected. Until a few decades ago, cholera had horrific death rates of 20% or more. The advent of so-called oral rehydration therapy—a simple solution that replenishes the body's electrolytes—in the 1970s has dramatically lowered those numbers, but it needs to be provided rapidly, as cholera can kill within a day. That can be a huge challenge in the places where cholera often strikes: poor countries with little infrastructure and a dearth of medical facilities.

    Today, an unofficial international standard says that mortality during outbreaks should be 1% or lower, says Claire-Lise Chaignat, head of the Global Task Force on Cholera Control at the World Health Organization in Geneva. Some countries in Asia that experience cholera often do even better, but mortality during outbreaks rates during recent outbreaks in Africa have been several times higher (see map). Early this week, the official case fatality rate in Haiti still stood at 6.4% but was dropping.

    One particular worry in Haiti is that a million or so people still live in camps, mostly in Port-au-Prince, where diseases spread easily. A 1994 outbreak among Rwandan refugees in Goma in the Democratic Republic of the Congo, in which more than 20,000 people perished, is a vivid reminder of how dangerous camps can be. So far, the disease has not reached the Haitian tent cities. Mintz, for one, says the camps are better organized than those in Goma, and people living there may actually be at an advantage compared with other Haitians because most drink chlorinated water and have a better chance at timely treatment.

  2. Research Ethics

    Questions From China Snag U.S. Trial of Nerve-Rerouting Procedure

    1. Hao Xin

    A running 5-year medical brawl in China has spilled over into Michigan, where it has delayed a clinical trial about to enroll patients. The trial, based at the William Beaumont Hospital in Royal Oak, Michigan, aims to surgically reroute the nerves of spina bifida patients to give them control of their bladder. Principal investigator Kenneth Peters confirmed last week that the U.S. National Institutes of Health (NIH)—which is funding the work—has asked for a review.

    Under fire.

    Xiao Chuan-Guo's reports of success in treating spina bifida patients have been challenged by Chinese critics.


    The urologist who invented the nerve-rerouting procedure, Xiao Chuan-Guo, has claimed phenomenal results in China—including an 87% success rate for 110 spina bifida patients at their 1-year follow-up visits. But the controversy surrounding his work is phenomenal, too. Earlier this year police charged Xiao, head of urology at the Union Hospital affiliated with Huazhong University of Science and Technology in Wuhan, with organizing street attacks on two of his critics. Those injured were Fang Shimin, who under the pen name Fang Zhouzi operates the Xin Yu Si or New Threads Web site (, and journalist Fang Xuanchang (no relation to Fang Shimin), who has edited magazine articles about Chinese patients who failed to benefit from Xiao's procedure.

    Xiao was convicted of “causing disturbance” and sentenced to 5.5 months of detention ( He has appealed the verdict. Science sent a request for comment to Xiao's lawyer by e-mail but did not receive a response by presstime.

    Questions about the clinical trial in Michigan based on Xiao's procedure reached the U.S. Department of Health and Human Services in March, when the so-called New Threads Volunteers, a watchdog group that tracks Xiao's research, sent a letter to the Office of Research Integrity (ORI) and the Office for Human Research Protections (OHRP). The letter alleged, among other things, that “the current clinical trials in the United States are based on dubious data.”

    ORI declined to take action, according to Eddie Cheng, a blogger, software engineer, and member of the Volunteers, who mailed letters about Xiao's study to ORI and OHRP. Cheng says ORI wrote back in March that the allegations weren't specific and that Xiao's work in China was out of its jurisdiction. Last week, however, OHRP confirmed in an e-mail to Cheng that it had asked the funding agency to evaluate the allegations.

    Xiao has many friends in the scientific community. Peters, head of urology at the Beaumont Hospital, and 30 researchers signed an open letter in support of Xiao in September urging China to “protect his human rights” and praising Xiao as “a compassionate man who is respected worldwide for his integrity and his innovative scientific contributions to society.”

    Xiao developed a nerve-rerouting procedure to treat neurogenic bladder disorder in patients with spinal cord injury (SCI). Nerve crossover was first proposed by an Australian surgeon in 1907; medical literature holds a scattering of partial success stories. But Xiao's approach—which he proposed in the late 1980s—bypasses the central nervous system by grafting a lower lumbar nerve to one or two sacral nerves below the spinal cord lesion, rerouting signals to bladder and urinary muscles. Xiao claims to have established a new pathway that can be used to initiate voluntary urination by scratching or squeezing skin on the thigh.

    After testing the idea on rats and cats, Xiao applied for and received an NIH grant in 1994 to study dogs at the Long Island College Hospital in Brooklyn, New York. According to his own published account, Xiao began a trial of the procedure with Chinese SCI patients at a hospital affiliated with a coal mine in Henan Province in 1995 and published final results from the SCI patients in 2003 in The Journal of Urology. This peer-reviewed article reported that of 15 male SCI patients—all with hyperreflexic neurogenic bladder (involuntary voiding)—who had the surgery, 10 gained satisfactory bladder function, two had partial recovery, two failed, and one was lost to follow-up.

    Critics see inconsistencies in the data. For example, in early reports (some in Chinese), Xiao described patients' recovery taking place between 10 and 12 months post-op, but the 2003 final report says that patients gained bladder function 12 to 18 months post-op. In addition, the depiction of all 15 patients as hyperreflexic in the 2003 report seems at odds with Xiao's previous reports, which described treating a mix of patients with hyperreflexic bladder and areflexic bladder (failure to void).

    Eric Kurzrock, chief of pediatric urology at the University of California, Davis, Children's Hospital in Sacramento, California, says Xiao's study is “extremely flawed” because of “patient selection bias.” Kurzrock is particularly critical of the claimed high success rate, because it is not based on data from a randomized, controlled trial.

    After treating SCI patients, Xiao began using nerve rerouting to treat bladder malfunction in children with spina bifida, whose spinal cords are generally not as damaged as those of SCI patients. The first privately funded trial at Beaumont Hospital, which took place in 2006 and 2007, included nine spina bifida patients and two SCI patients; Peters and co-authors reported preliminary results from spina bifida patients, but results on SCI patients have not been reported. The current NIH-funded trial aims to enroll about 16 spina bifida patients; the original design was not blind and had no control group. Peters says NIH has “created an oversight committee for our study. We met with them a few weeks ago and are addressing their comments. We will be submitting a revised protocol soon for their review.”

  3. Convention on Biological Diversity

    U.N. Biodiversity Summit Yields Welcome and Unexpected Progress

    1. Dennis Normile
    Snake oil.

    Brazilian pit viper venom was used to develop a blockbuster hypertension drug, but Brazil didn't profit. A new treaty gives countries a stake in the use of their resources.


    NAGOYA, JAPAN—Delegates, advocates, and observers were braced for the worst going into the last week of a biodiversity summit here. Instead, at a marathon closing plenary session, the parties agreed to an ambitious plan to halt the loss of biodiversity, an agreement to combat biopiracy, a scheme to increase conservation funding, and a raft of related policy statements. Not everyone got what they wanted, but most got something they could live with.

    The plan to “take effective and urgent action to halt the loss of biodiversity” is a “pretty good deal” in the eyes of James Leape, director general of the Geneva-based conservation organization WWF.

    The agreement to equitably share benefits resulting from research using natural resources “should help, not hinder,” academic researchers doing fieldwork while protecting the interests of developing countries, says Geoff Burton, an Australian expert on the issue.

    And although funding pledges proved disappointing, the scheme to ramp up monetary support is encouraging, says Gustavo Fonseca, head of the natural resources team at the Global Environment Facility (GEF) in Washington, D.C., a multilateral entity supporting developing world sustainable development.

    These agreements, adopted at the 10th meeting of the Conference of the Parties (COP 10) to the 1992 Convention on Biological Diversity (CBD), took years of preparatory work, 2 weeks of intense negotiations here, and deliberations at a final plenary session that ran past 2 a.m. on 30 October. Delegates were relieved and proud that the meeting produced substantive results, in marked contrast to the U.N. conference on climate change in Copenhagen last December, which accomplished little.

    The first of a trio of agreements many delegations wanted to treat as an all-or-nothing package addresses access to genetic resources and the sharing of benefits arising from their use. The existing CBD recognizes the sovereign rights of states over their natural resources. But developing countries had long wanted a document with more specific details, and indigenous groups have demanded recognition of their rights to resources on ancestral lands and to traditional knowledge. Advocates say there are hundreds if not thousands of examples of biopiracy: drugs, dietary supplements, and cosmetics based on traditional knowledge of the medicinal properties of plant and animal products that have been commercialized without authorization or any benefits being returned to local communities. Brazilian delegates point to the case of the venom of Bothrops jararaca, a Brazilian pit viper. Locals had long known that the viper's bite thins blood so much that it seeps through vascular walls, causing a precipitous drop in blood pressure; victims often bleed to death. After a Brazilian researcher isolated the active compound, researchers in the United Kingdom and the United States elucidated the mechanism and developed a synthetic compound that mimics the venom's effect. The company now known as Bristol-Myers Squibb put the resulting hypertension drug, Captopril, on the U.S. market in 1981. Neither Brazil nor the local community benefited from sales that ran to billions of dollars.

    To resolve such issues, the convention launched formal talks to produce a protocol on access and benefit sharing—ABS, for short—in 2004. By the start of COP 10, negotiators had produced a draft document stating that those seeking to use genetic resources or traditional knowledge for research or commercialization must obtain prior informed consent from both the country and indigenous communities involved and to agree on terms to share monetary and nonmonetary benefits, including intellectual property rights.

    Two particularly sticky issues weren't resolved until the last day of the meeting. Developing countries and advocates for indigenous peoples wanted the provisions to apply retroactively. In the end, retroactivity was dropped in favor of a call for a “global multilateral benefit-sharing mechanism” to address cases in which genetic resources were acquired prior to the new agreement.

    Compliance was also a point of contention. The draft protocol included a long list of “checkpoints”—including patent offices, research institutions, and scientific journals—at which the proper acquisition of materials or knowledge would be verified. This, too, was simplified, leaving it up to individual countries to establish compliance systems. “It is probably the best we could do at Nagoya,” says Paulino Franco de Carvalho, head of the Brazilian delegation.

    Academic researchers have worried that the protocol might hinder basic research in areas such as taxonomy. Overall, the new protocol “will assist academic researchers insofar as current obstacles faced in many countries will be removed,” says Burton, who participated in the negotiations and in the adoption of ABS legislation in Australia. He says that in the absence of an international agreement, some developing countries have made access so difficult that it can take up to 2 years for researchers to navigate the permitting process.

    Under the new protocol, ratifying countries must designate a “national focal point for access and benefit sharing” to provide all necessary information on permits. It also calls for decisions to be rendered within a reasonable time. And there should be “simplified access procedures” for noncommercial research that Burton hopes will result in quick and inexpensive permitting. In turn, all parties must share nonmonetary benefits, such as joint authorship of scientific papers or at the least acknowledgment of the use of traditional knowledge, says Joji Cariño, an official of Tebtebba, a Philippine indigenous people's advocacy group. Academic researchers will also have to track the use of any materials by third parties, as commercialization will require further negotiations with provider countries and communities.

    The second of the three major all-or-nothing agreements was the adoption of a strategy to stem biodiversity loss by 2020. The plan's 20 Aichi Targets, named after the prefecture that is home to Nagoya, include expanding protected areas to cover at least 17% of the world's terrestrial and 10% of the total marine surface (see table). Conservationists had been pushing for 20% in total. “Studies show that's the bottom line needed to conserve species,” says Alison Satterfield, head of science for BirdLife International in Cambridge, U.K.

    WWF's Leape says 17% “is not great” but is “a big step forward.” And targeting 10% of marine areas “is a 10-fold expansion” over the 1% currently protected, he says.

    In 2002, parties to the CBD also set a number of conservation targets for 2010 and then largely missed them. In an attempt to avoid such failure, the strategic plan requires countries to describe their conservation plans and report progress to the convention. “We're not just left with bio-aspirations,” says John Fitzgerald, policy director for the Society for Conservation Biology in Washington, D.C. “We have building blocks to achieve targets, and this will allow for corrective action in a timely way.”


    Of course, these new efforts will take money. Japan pledged $2 billion, but no other countries put significant new money on the table. In a new move, however, the parties did agree to increase funding according to specific percentages or amounts, with details to be worked out by the time of the COP 11 meeting, scheduled for 2012 in New Delhi, India. GEF's Fonseca says he is “very happy” with the agreement. “This is the first time specific targets will be set; this is progress,” he says.

    The ABS protocol requires ratification by at least 50 countries to go into effect. The other two agreements are effective under the CBD agreement.

    In addition to approving changes in the CBD itself, delegates called for a moratorium on geoengineering schemes to avert climate change and endorsed a request to the U.N. General Assembly to create an Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services that would produce scientific assessments on biodiversity issues much as the Intergovernmental Panel on Climate Change does. “We're quite excited about this; it's really needed,” says Thomas Elmqvist, an ecologist at Stockholm University and a member of the Swedish delegation.

  4. ScienceInsider

    From the Science Policy Blog

    Attorneys filed more paperwork last week in two federal courts regarding the legality of human embryonic stem cell guidelines set by the National Institutes of Health (NIH). One set of documents is the final word to U.S. District Judge Royce Lamberth, whose 23 August ruling briefly halted federally funded hESC research. At the same time, an appeals court has set 6 December for oral arguments addressing Lamberth's preliminary injunction.

    A survey of some 600 intramural scientists and officials at NIH suggests that tough new restrictions on outside consulting have reduced by a third the number who engage in such activities. But 80% of respondents said the rules are too restrictive. The story was hotly debated in the ScienceInsider comments section, with one reader fearing that the crackdown could create “a backlash that harms all federally supported researchers.”

    A new study of marine aquaculture finds that industrial fish farms can cause great environmental harm if there are too many of them. A new index could interest seafood buyers and policymakers evaluating how farms are regulated.

    NIH has given $2 million grants to six scientists in a new program aimed at increasing diversity of the scientific workforce. One grant would create an Institute for Accessible Science, with a wet lab and a social network to help students and scientists with disabilities.

    Senator Chuck Grassley (R–IA) is concerned about outside groups paying for travel by intramural researchers at the National Cancer Institute. Staffers say the trips, often to other countries, are an important way to interact with the international science community.

    For 2010 election coverage and more science policy news, visit

  5. Earthquake Recovery

    Slew of Landslides Unmask Hidden Geological Hazards

    1. Hao Xin
    On shaky ground.

    Debris flows this summer devastated Yingxiu (left) and Qingping.


    CHENGDU, CHINA—Just before midnight on 7 August, heavy rains in the mountains north of Zhouqu, in western China's Gansu Province, unleashed a torrent of mud, boulders, and rubble on the slumbering town. Barreling in at about 10 meters per second, the debris flow smashed approximately 5500 houses, leaving 1765 people dead or missing.

    Ma Dongtao had suspected that Zhouqu was a tragedy waiting to happen—and he warned about the risks about a decade ago. In the summers of 1996 and 1997, Ma, a geotechnical expert now at the Institute of Mountain Hazards and Environment (IMHE) of the Chinese Academy of Sciences in Chengdu, and a colleague assessed hazards in the Zhouqu area. Like many settlements in mountainous regions, Zhouqu is built on an alluvial fan from earlier debris flows. The August disaster was the 12th damage-causing event since 1823. The researchers estimated that some 25 million cubic meters of loose rock and sediment had accumulated in two gullies north of town. Human activities like quarrying contributed to the precarious mass, but most of it, Ma believes, was deposited by landslides and rockfalls after a big earthquake in 1879. The findings suggested that debris flows could strike “more than 100 years after a major shake,” Ma says.

    If he is right, many river valleys in western China harbor hidden hazards. According to Tang Chuan, a geologist at the State Key Laboratory of Geohazard Prevention and Geoenvironment Protection (SKLGP) at Chengdu University of Technology, some 60,000 landslides occurred in valleys and gullies during and shortly after the magnitude-7.9 Wenchuan earthquake that struck in May 2008.

    During this year's rainy season now drawing to a close, downpours triggered more than 1000 debris flows across China, mostly in western Sichuan. So far, the number of debris flows in 2010 is more than double the total for 2006, a bumper year for geological disasters. Experts blame the Wenchuan quake, and they warn that such hazards pose long-term challenges to earthquake recovery.

    Within a week of the Zhouqu disaster, hundreds of debris flows to the south in Sichuan Province blocked roads and overran at least 11 settlements for people displaced by the Wenchuan earthquake. On the night of 13 August, a debris flow near the epicenter dumped about 700,000 cubic meters of sediment into the Min River, which overran its banks and flooded resettlement homes in Yingxiu.

    The same night, a giant debris flow inundated Qingping, site of the second biggest landslide triggered by the Wenchuan earthquake. The flow's runout, about 3 million cubic meters of sediment, was double that of Zhouqu, according to a survey by SKLGP geologist Yu Bin. But the Zhouqu disaster had put Qingping on high alert. When rains turned heavy at night, the town was evacuated about 2 hours before the debris flow struck. The toll—14 dead or missing—could have been far higher. But the threat to Qingping continues. Two more debris flows pummeled the town on 19 August and 18 September. The total runout of the three flows was a small fraction of the 50 million cubic meters of boulders, rocks, gravel, and soil dumped into the gully by the quake-triggered landslide, says Yu.

    The third rainy season since the Wenchuan earthquake has been a wake-up call. According to Tang, experts have underestimated the potential severity of postearthquake secondary disasters. In the aftermath of the 2008 earthquake, the Sichuan government commissioned an SKLGP team to assess future hazards to help guide reconstruction. The team's report that October forecast an elevated risk of landslides and debris flows in the earthquake zone for 3 to 5 years after the quake. Tang, however, thinks the risk will remain high for at least a decade.

    Indeed, this season's disasters could be a harbinger of future woes. So far, debris flows in the 2008 quake zone have occurred in small catchments with drainage areas of less than 10 square kilometers. It takes longer for sediments to be transported out of larger catchments; for that reason, disasters in drainage basins with areas bigger than 10 kilometers could strike 20 or more years after a tremor, says IMHE's Xie Hong, who has studied regional geological hazards for more than 2 decades. “We should be worried about dormant debris flow gullies in large catchments in the earthquake zone,” says Xie. Because sediment builds up gradually in large catchment areas and it takes heavier rains to sweep it out, “people have forgotten about past disasters and have built houses and factories in these gullies,” says IMHE geotechnical engineer Wang Quancai.

    Qingping's leaders made the right decision by evacuating—but they also got lucky. It's hard to accurately predict geological hazards, Xie says. Part of the challenge is that debris flows are primarily triggered by localized torrential rains that are difficult to forecast.

    The surest way to safeguard lives and property is to avoid building near debris flow paths, says Xie. Field surveys can look for telltale signs of dangerous buildups. After the 1999 Chi-Chi earthquake in Taiwan, debris flows in the affected area were more frequent and triggered by smaller amounts of rainfall, says Tang. He and Yu suspect that this phenomenon—threshold lowering—is occurring in the area affected by the Wenchuan quake. They are racing to gather precipitation data and survey as many disaster sites as possible to estimate runouts and flow rates before next season's debris flows bury this year's—both compounding and further cloaking the risk.


    From Science's Online Daily News Site

    Did 'Snowball Earths' Trigger Animal Evolution? Researchers have noted that two globe-girdling ice ages roughly coincided with the appearance of the earliest animals in the fossil record. Now biogeochemist Noah Planavsky of Woods Hole Oceanographic Institution in Massachusetts and colleagues propose in Nature that “snowball Earth” glaciations could have spurred evolution by increasing oxygen in the air and oceans.

    During a snowball-Earth episode, the team argues, the ice sheets ground up continental rock, releasing phosphorus. This key nutrient for marine plants then washed into the oceans when the glaciers retreated, fertilizing algal blooms that could drive a surge in the production of organic matter. And the added organic matter that settled into the mud on the ocean bottom would leave additional oxygen behind, eventually boosting atmospheric and oceanic oxygen.

    To check how the oceans' phosphorus content varied over time, the team measured phosphorus in minerals formed in ancient oceans. During the past 3 billion years, phosphorus abundance varied little, except for a surge lasting from about 750 million years ago to about 635 million years ago, at the same time as two snowball-Earth episodes.

    Other researchers call the link a fascinating idea but say it needs more support from the geologic record.


    Hellish 'Super-Earths' Abound Bad news for E.T.: Astronomers predict that many of the galaxy's planets orbit so close to their parent stars that their surfaces are seas of molten lava—hardly ideal conditions for life.

    Kevin Schlaufman, a graduate student at the University of California, Santa Cruz, and colleagues used computer models to simulate a theoretical extrasolar planet population. A large number of these alien worlds were hot super-Earths, rocky planets up to 10 times the mass of Earth that orbit their host stars in 24 hours or less, the team reports in a paper to be published in The Astrophysical Journal Letters.

    Although such planets start off farther away from their stars than Earth is from the sun, their stars slowly pull them in over about 100,000 years, ripping them apart and eventually vaporizing them. Schlaufman notes that life on these scorching planets is totally out of the question.

    NASA's Kepler mission (pictured) to find Earth-like worlds is expected to announce the discovery of a slew of such hot super-Earths by early next year.


    New Monkey Species Allergic to Rain? Scientists have discovered a new monkey species in the mountain forests of Burma. But with only an estimated 260 to 330 individuals alive, Rhinopithecus strykeri is already critically endangered, Thomas Geissmann of the University Zurich, Irchel, in Switzerland and colleagues report in the American Journal of Primatology. Locals call the creature “mey nwoah” or “myuk na tok te,” meaning “monkey with an upturned nose.” Popular legend says the monkeys' uplifted nostrils make them sneeze when it rains, so they endure downpours by tucking their heads between their knees. The animals are so rare that primatologists have yet to glimpse one alive. Instead, they relied on information from hunters and carcasses to estimate their numbers and create the image above using Photoshop. Although not a key game species, the monkeys often get caught in bear traps, and the influx of Chinese logging companies is further jeopardizing their habitat, the researchers say.


    Love Bugs Bacteria that inhabit fruit flies help sway their choice of partners, according to a new study.

    Recreating a 1980s experiment, microbiologist Eugene Rosenberg of Tel Aviv University in Israel and colleagues split one population of flies into two and fed them different diets. When combined after many generations, female flies preferred to mate with males raised on the same diet, a finding that had perplexed previous experimenters.

    Rosenberg and his colleagues thought this was because changing the flies' diet changed their bacteria. Sure enough, when the flies were treated with antibiotics before being placed together, the female flies were no longer choosy. The two groups of flies also had different levels of four sex hormones that signal when the flies are ready to mate, the team reports in the Proceedings of the National Academy of Sciences. The bacteria may even be driving speciation by causing individuals to mate selectively with each other over so many generations that they eventually become distinct from their brethren.

    Read the full postings, comments, and more at

  7. China

    Supercomputer Leaves Competition—And Users—in the Dust

    1. Richard Stone and
    2. Hao Xin

    FUZHOU, CHINA—China's new supercomputer,Tianhe-1A, is also the world's fastest, topping by 47% the current titleholder, the Jaguar XT5 system at Oak Ridge National Laboratory in Tennessee. But while Chinese officials are hailing the 2.5-petaflops supercomputer as an example of indigenous innovation, some Chinese researchers are troubled by another fact: The number of their colleagues able to tap even a thimbleful of the machine's power is surely minuscule.

    Tianhe-1A was developed by the Central Military Commission's National University of Defense Technology (NUDT) in Changsha and housed at the National Center for Supercomputing in Tianjin, which is classified as a secret facility. Despite its pedigree, the machine is expected to focus on civilian applications, including weather forecasting, animation, and modeling of petroleum reserves, according to Liu Guangming, director of the supercomputing center.

    It may be years, however, before Chinese software catches up with the hardware. It's a “big embarrassment” for supercomputer developers in China that their powerful machines have few users, says Xu Rongsheng, a computational physicist turned network security expert in Beijing. “Few Chinese researchers know how to model a problem mathematically,” says Xu.

    Under the hood of the supercomputer, housed in 120 refrigerator-sized cabinets, are 14,336 Intel Xeon CPUs and 7168 Nvidia Fermi graphics boards. NUDT engineers devised a novel interconnect—twice as fast as the U.S. standard—to take advantage of the number-crunching speed of graphics chips and the capacity of CPUs to solve complex equations. Developers have also swapped in some of China's own Feiteng-100 CPUs for Intel chips.

    New leader.

    Software engineers work on China's Tianhe-1A supercomputer, which is the world's fastest.


    “The performance has proved that our CPU is very powerful,” China's science minister, Wan Gang, said here this week at the annual meeting of the Chinese Association for Science and Technology. “It's a substantial enhancement of the Tianhe-1 computer that was number seven on the [most recent] Top 500 list,” says Jack Dongarra, a computer scientist at the University of Tennessee, Knoxville, whose new listing of the fastest computers in the world comes out on 15 November.

    Applications, however, are where the rubber will meet the road. “Nurturing users for supercomputers is like a restaurant,” Liu told Xinhua. “It not only needs to cater to customers with different tastes but also needs to have large-account customers to fill the restaurant.”

    For now, most supercomputer users in China are ordering off the kids' menu. Only 1% of the applications on China's previous speed champ, the Dawning 5000A at the Shanghai Supercomputer Center, use more than 160 of the machine's 30,720 cores. For comparison, 18% of the applications running on Oak Ridge's Jaguar XT5 use 45,000 to 90,000 of the machine's 150,162 cores, according to a presentation at last year's announcement of China's top 100 fastest computers. “A supercomputer without software is like a wild horse without a harness,” says Zhang Yunquan, a parallel computing researcher at the Institute of Software of the Chinese Academy of Sciences in Beijing. “Its horsepower is wasted.”

    The problem, in part, is cost. Most industrial applications on Chinese supercomputers use commercial software purchased from the United States and other countries, Zhang says. But because the price is proportional to the number of CPUs supported by the software, few Chinese users can afford licenses that support large numbers of CPUs.

    Wan told Science that he would like to see China develop its own applications in areas such as climate modeling and biotechnology. That would require a considerable cash infusion in the 12th 5-year plan, set to begin next year. Software now gets only a penny of every dollar spent on hardware development, Zhang says.

    It may take months for Tianhe-1A to close in on its theoretical peak speed of 4.7 petaflops. And by then it almost surely will have relinquished its top rank. According to Dongarra, five supercomputers in the 10-petaflops class are being built in Japan and the United States, home to more than half the supercomputers on the top 500 list.

  8. Patent Policy

    Amicus Brief Unfriendly to Gene Patents

    1. Eliot Marshall

    The U.S. Justice Department waded into a battle last week over whether genes can be patented, surprising many with a sweeping new proposal. It argued in an amicus brief filed with the U.S. Court of Appeals that “genomic DNA that has merely been isolated from the body without further alteration or manipulation” should not be eligible for patenting. DNA of this type should be treated as a “product of nature,” not an invention, the brief says.

    Locus of dispute.

    Patenting this gene was a mistake, says the U.S. government.


    Experts disagree on the likely impact of this principle—if adopted. The Biotechnology Industry Organization (BIO), a Washington, D.C., lobby, says the new stance could undercut many biotech ventures, particularly in agriculture. In a statement, BIO President and CEO James Greenwood said limiting gene patents would be at odds with “more than 2 decades” of U.S. national policy. Greenwood warned of dire consequences: If adopted, the change “would undermine U.S. global leadership and investment in the life sciences, harm U.S. economic growth and competitiveness at home and abroad, and be counterproductive to the Administration's own initiatives to fight cancer, develop renewable sources of energy,” and other goals.

    But the new position really is “not all that far-reaching, despite the rhetoric,” says Robert Cook-Deegan, an expert on genetics and patents at Duke University's Center for Genome Ethics, Law & Policy in Durham, North Carolina. Companies with early gene patents that want to maintain exclusive control of DNA might be affected, he says, but not younger ones that aim to develop products based on whole-genome analysis, where thousands of genes must be used.

    One company sits squarely in the crosshairs: Myriad Genetics in Salt Lake City, Utah, which owns patents on the breast and ovarian cancer genes BRCA1 and BRCA2. In March, a New York federal district court ruled that some of Myriad's key BRCA patents were invalid and should never have been granted (Science, 9 April, p. 153). The judge in that case agreed with the Public Patent Foundation and the American Civil Liberties Union in New York City, which wanted the patents thrown out on grounds that “isolated DNA” is not an invention. Myriad appealed.

    In its amicus brief, Justice agreed in part with the lower court judge. “The chemical structure of native human genes is a product of nature,” Justice said, “and it is no less a product of nature when that structure is ‘isolated’ from its natural environment than are cotton fibers that have been separated from cotton seeds or coal that has been extracted from the earth.”

    But Justice's brief also seeks to limit the scope of the ruling handed down by the New York court, arguing that some DNA patents—such as those covering complementary DNA, vectors, and recombinant plasmids—should continue to be allowed.

    It is not clear who directed that this brief be prepared; some in the biotech community speculate that it was initiated by policymakers at the White House. Nor is it clear whether the brief presages an actual change in patent policy. When asked about this, a Justice Department spokesperson said only, “the brief speaks for itself.”

  9. Neuroscience

    China's Brain Mappers Zoom In on Neural Connections

    1. Kristen Minogue
    Wire mapping.

    A new brain atlas highlights the neural circuitry in a mouse cerebral cortex.


    Anyone in business, and even just fans of The Apprentice, knows that connections matter. Neuroscientists understand that, too, which is why a research team in China has gone to great lengths to create the most detailed three-dimensional map yet of all the connections between the neurons in a complete mouse brain. The project, unveiled this week online in Science (, hasn't revealed any major surprises so far, but its data and the new automated instrument that produced the brain atlas provide an important foundation for future studies, researchers say.

    Mapping all the connections between neurons is crucial to understanding how the brain functions, or malfunctions, explains neuroscientist Mihail Bota of the University of Southern California in Los Angeles. Trying to figure out the brain without looking at its wiring, he says, is like trying to fix a car with all the right components but no idea how they're connected: “You don't know the input, you don't know the output, you don't know how the signal is processed.”

    The new brain atlas project resembles several recent efforts, though the previous ones have not captured the same kind of detail as the China effort. Last year, a team of California researchers began slicing up the brain of psychology's most famous amnesiac, Henry Gustav Molaison, to figure out what exactly messed up his long-term memory (Science, 26 June 2009, p. 1634). And in 2006, the Allen Institute for Brain Science in Seattle, Washington, spent $41 million on its own 3D mouse brain map, which documents gene expression at a cellular resolution in an online database available to neuroscientists.

    But neither of those projects imaged a whole brain at a resolution showing the axons and dendrites connecting all the nerve cells. To accomplish this challenging task, the researchers, led by Li Anan of the Britton Chance Center for Biomedical Photonics in Wuhan, China, used a traditional slice-and-scan technique but in a newly automated fashion. After removing the centimeter-size brain from a mouse, they soaked the organ for 6 months in a cellular stain, then dried and baked it. Next, they placed the brain on a chopping block in the micro-optical sectioning tomography machine, a new instrument the team developed that incorporates a diamond knife that can slice tissue into wafer-thin strips micrometers thick. A light microscope and image recorder immediately captures a picture of each brain strip before the next one is cut. The instrument worked 10 days nonstop to collect the data—eight terabytes in all—for the mouse brain atlas.

    Documenting normal neuronal connections may be important because many of the brain's more complicated maladies, such as autism or schizophrenia, may be rooted in circuit problems, according to neuroscientist Jason Bohland of Boston University. There's a growing feeling among neuro scientists, he says, that social or linguistic disorders could be caused by disruptions in the pathways between nerve cells—and in order to figure out what's going on at that level, scientists need more detailed maps. “You don't have complex behavior emerging at the level of brain regions. You have it emerging at the level of circuits, ” he says.

    The new images offer a broad, comprehensive outlook on the brain, one more focused on the brain's architecture than its biology, says Kelly Overly, a neuroscientist at the Allen Institute. Still, it could be a valuable comparison tool for more specific, targeted studies. “There's so many things you could do with this sort of data, ” says Bohland.

  10. Panning for Science

    1. Karen A. Frenkel*
    Rock art.

    A GigaPan of a remote outcrop in Saudi Arabia helps see and date drawings chipped through the “desert patina” on the rock face.


    When NASA's twin mars rovers began sending detailed pictures to Earth in January 2004, Randy Sargent, a computer scientist working on visualizations of those images, was enthralled by the sense of actually exploring martian terrain. Onboard each rover, a camera known as the Pancam swiveled and tilted on command from NASA scientists. Sargent and his colleagues combined each exposure into a stunning digital panorama of the Red Planet's landscape. Scientists at the Jet Propulsion Laboratory in Pasadena, California, could interact with the images on their computer screens, zoom in on fine details, hypothesize about what they were seeing, and pick the rovers' next destinations. “The pan had so much resolution, it felt like peering through a little hole in the wall into another world,” recalls Sargent's manager, robotics group leader Illah Nourbakhsh at NASA Ames Research Center in Moffett Field, California, who was then on sabbatical from Carnegie Mellon University (CMU) in Pittsburgh, Pennsylvania. “What stunned us was this feeling of presence, which a simple picture that is not interactive doesn't give you.”

    That experience led directly to a technology that has become a powerful tool for teaching and public engagement with science and the natural world. Scientists are also using it for projects as diverse as analyzing Middle Eastern petroglyphs, monitoring an urban forest, archiving a museum insect collection, studying a collapsed honey bee colony, keeping tabs on glaciers, examining erosion in a jaguar reserve, and viewing Galápagos fish clustered into a bait ball.

    Soon after the martian panorama renderings, Nourbakhsh challenged his team to think creatively about “blue sky” projects they could tackle. Aware of the intense reverence astronauts felt as they gazed at Earth from space, Sargent proposed bringing that kind of experience down to Earth by building affordable equipment anybody could use to create explorable images. Nourbakhsh immediately recognized the idea's potential for changing the relationship between viewer and image. “An explorable image is a disruptive shift away from the static image you just glance at, because now you have the power of exploration,” he says. “That sets people up with a different mindset because they decide where to zoom, where to go, what structures and details to see. And it's not virtual, it's not a video game. It's real.”

    Sargent developed a prototype for what is now the GigaPan system. Users punch numbers into a keypad on a robotic mount for a digital camera, specifying how expansive they want their panorama to be. A microprocessor calculates the size and number of exposures needed for the pan and moves the camera accordingly. A small robotic finger pushes the shutter button for each exposure. These are stitched together to form a panorama with a resolution 1000 times that of HDTV. The largest GigaPan has 100 gigapixels.

    The final image contains more data than most personal computers can handle, so Nourbakhsh and his team developed a massive server system and Web site,, for storing and accessing GigaPans. When viewers zoom in on an area of an image, they seem to fly into the image itself. The result is an immersive, interactive experience that can reveal surprising details—an ant on a leaf in a forest, or a hummingbird sipping nectar from a flower in a backyard. It's like viewing nature through a huge magnifying glass.

    Sargent, who now has a joint appointment at NASA Ames and CMU, and Nourbakhsh, head of CMU's CREATE Lab, founded GigaPan Systems LLC in 2008 to manufacture and sell the systems at close to cost ($299 to $895). They are continuing to develop technology for creating and viewing high-resolution scans as co–principal investigators of the Global Connection Project, a joint development between NASA Ames, the CREATE lab, Google Inc., and the National Geographic Society.

    Gigapixel science

    GigaPans have captured the public's imagination. Five thousand systems have been bought, and today the site hosts 40,000 public panoramas that draw 20 million visitors a year; another 20,000 are in private areas of the site while contributors work on them. Sargent and Nourbakhsh began training scientists to shoot GigaPans in 2008, and some 120 investigators are now using the system in their research. In mid-November, scientists will share findings at the Fine International Conference on Gigapixel Imaging for Science, hosted by CMU and the CREATE lab.

    Fine details.

    Snails in an urban forest and the texture of a beetle's carapace show the power of GigaPans to home in on details.


    Paleontologist K. Christopher Beard and archaeologist Sandra Olsen of the Carnegie Museum of Natural History in Pittsburgh and photographer Richard T. Bryant trained their GigaPan on remote Saudi Arabian petroglyphs, including the Eagle's Nest in Juba. The engravings date back to the Holocene Wet Phase (9000 B.C.E.-5000 B.C.E.) when the environment resembled that of today's African savanna, and lions, gazelles, cheetahs, wild asses, and hyenas roamed the land. Camel drawings accompanied by writing appeared in 1500 B.C.E, followed by images of horses and chariots. “You can see grains of sand, details of grooves and peckings, and the relationships between the images, which is important for dating,” marvels Olsen, who runs the museum's anthropology section. The technology reduces the time spent on expensive on-site research. “We can be there briefly producing GigaPans, take that data home, and study images at our leisure on a wide-screen computer,” Olsen says.

    The technology also lets Olsen share data easily with colleagues and peer reviewers. “This is the closest to being there,” says Olsen. Such data sharing lets colleagues perform the same kind of analysis she does, and below her panorama they can post details they found and annotate them.

    M. Alex Smith, a molecular ecologist at the University of Guelph in Canada, is deploying the technology closer to home. He is using GigaPans to monitor the “Dairy Bush,” an urban forest that has been part of the Guelph campus since 1830. The 8.5-hectare wood lot contains rare and listed species, but this living laboratory for ecology students has degraded as its surroundings changed from farmland to condos and shops, and invasive species gained a foothold. To monitor such pressures, Smith abandoned the rough, “Victorian method of pencil and paper” for the GigaPan's precision. Since August 2009 he has taken weekly shots from the same location, which enabled him to discover phenomena and return with questions he had not known to ask. “There's a chokecherry on the lower left quarter of the pan full of insects from spring to fall that I wasn't seeing,” he says, “and assassin bugs and parasitic wasps I wasn't aware of.” Users worldwide have discerned, grabbed, and sent shots of snails, caterpillars, and trash.

    Smith has also produced a time-lapse video of his series of pans, now on YouTube. The video helped him study the formation of the Dairy Bush tree canopy, which is critical to quantifying a forest's response to climate change. Time-lapse video is not zoomable now, but at the November conference Sargent and Nourbakhsh will unveil a viewer that will let users zoom and move back and forth in time.

    For John Rawlins, curator of invertebrate zoology at the Carnegie Museum of Natural History, the GigaPan is an opportunity to archive and share a 17-million-bug collection. The advantage of “pixel traveling” is “scary in a way,” Rawlins says, because the staggering sharpness reveals minutiae—spinules (thorny spikes) on legs or the microsculpture of forewings, for example—that can easily be missed while examining a bug under a microscope. Rawlins forecasts that such detailed and accessible archives will allow researchers to identify insects rapidly using automated image analysis and pattern searching.

    With that goal in mind, Rawlins is collaborating with Gene Cooper, president of Four Chambers Studio in Vallejo, California, and CMU to develop a microGigaPan using an optical microscope. One effort involves imaging a Powdermill butterfly from the 1950s. Rather than compare two side-by-side photographs of its front and back, this system makes possible simultaneous inspection through pixel layers of varying transparency, so the viewer can evaluate wing markings as if passing through the insect. And the next step beyond microGigaPans is coming soon: nanoGigaPans, with as high as 8000 times magnification (0.01 gigapixels). NASA Ames's Jay Longson and Rich Gibson have adapted scanning electron microscopes to produce extreme close-up pans of insects, cells, and seeds.

    There are drawbacks to the technology. It can take hours to shoot sections of a pan and stitch them together, for example, and sometimes the stitching software has trouble matching uniform patches, like sky. And Nourbakhsh is concerned that his team has created yet another technology that enables people to spend all their time exploring on their computers instead of experiencing the world firsthand. But from martian vistas to cellular landscapes, GigaPans are putting science in the picture in interesting new ways. Some day a picture may well be worth 1000 gigapixels.

    • * Karen A. Frenkel is a science writer in New York City.

  11. Hydrology

    Out of the Mist

    1. Gaia Vince*
    Netting the fog.

    Large plastic nets suspended on top of a hill trap moisture from the sea air to provide water in coastal Lima, where it rarely rains.


    LIMA—On a sand dune on the outskirts of this city, residents of a shantytown are attempting to grow a forest. This coastline is one of the driest regions on Earth—Lima receives less than 1.5 centimeters of rain per year. Nevertheless, the forest plan is not as crazy as it sounds, as these Incan hills were wooded until Europeans cut the trees for lumber in the 1600s.

    Javier Torres Luna is hoping that reforesting the dunes above his hastily constructed plywood home will provide a long-term solution to an urgent problem: There is no water in his community for drinking, washing, or sanitation. And there is certainly none for forestry irrigation.

    But change is in the air. Literally.

    It's not that there's no water in Lima; it's just that there's no rain. From May through November, the chilly Humboldt ocean current cools the water-laden air coming from the Pacific, preventing rain along the coast. Instead, this thermal inversion blankets the city in a thick, gray fog.

    Over the past couple of years, Luna and his neighbors have erected a series of 4-meter-high nets at the top of the dune to capture precious drops from the wet air. In as few as 4 years, Luna's irrigated saplings will themselves trap the fog, creating a microclimate that should yield a self-sustaining runoff.

    Fog harvesting and other experiments, such as painting mountains (see p. 751), are how Luna and other Peruvians are trying to adapt to a heightening water crisis. Peru is losing its glaciers, a key source of water for the country, and the government is struggling to come up with solutions, particularly for Lima. “Fog nets are an extremely useful idea,” says Elizabeth Silvestre, scientific director of the National Meteorological and Hydrological Service in Lima. “As water shortages become more of a pressing issue, we are going to have to expand adaptive techniques like this.”

    A thirsty city

    The world's largest desert city after Cairo, Lima is entirely dependent for its water and its electricity on the seasonally erratic, drought-prone Rimac River. Two-thirds of the glacier at the Rimac's headwaters has disappeared, decreasing the river's glacier-contributed volume by 90% in the past 40 years. The little—highly contaminated—water that remains is primarily from rainwater.

    Unfortunately, because of climate change, the glaciers are only getting smaller. Not only are warmer temperatures melting glaciers, but rain that used to fall as snow is also washing them away. In just 30 years, Peru's total glacier-covered area has shrunk from 2000 to 1500 square kilometers. That represents an estimated 7 billion cubic meters of water—the equivalent of 10 years of water consumption in Lima. To make matters worse, the lakes at the base of the glaciers, on which thousands of rural people depend, are disappearing as well.

    Water shortages and drought have driven many people, such as Luna, from the countryside to the cities. More than 80% of Peru's population now lives on the country's desert coastal strip. Well over half of them—9 million—call Lima home. This migration is putting even greater pressure on the city's dwindling water resources.

    Part of the problem is that the state agency charged with managing Lima's water supply, Sedapal, is not doing a great job, losing by its own admission some 40% of the city's 220-million-cubic-meters-per-year supply through leakages and theft. Even in the wealthier parts of downtown Lima, businesses and residences periodically have nothing flowing through their taps.

    But the problem is far worse in the 1800 slum communities that are home to some 2 million migrants. There, it can take decades to be hooked up to the city's supply, says Abel Cruz, director of Peruvians Without Water, an action group started by Cruz in reaction to the poorest Peruvians having to pay the most for water. Lacking a municipal source, they must hire private water trucks, paying 10 times what downtown Lima residents pay for city water.

    “And because these water companies are private and not monitored, they supply cheap, contaminated water that makes us sick,” says Cruz, who lives in a community neighboring Luna's. The slums have a high incidence of dysentery and other waterborne diseases.

    Out of thin air

    Luna and his neighbors have given up waiting for the city's help. With assistance from the German nonprofit organization Alimón, the community has built reservoirs and tanks and constructed 8-by-4-meter plastic nets, supported by steel cables secured to poles, on the top of the dune to trap the precious fog. Fog-carrying wind from the ocean collides with the nets, and all the condensing water sounds like a gushing fountain. In the sunny season, January to April, weeks can go by without the nets collecting a drop, but from May through November, the fog is a thick, daily occurrence. The record catch per net is 590 liters in a single day. “We had no idea it would work so well,” Luna says.

    Desperate measures.

    At 4500 meters above sea level, Peruvian villagers are painting a mountain-side white to try to keep it cool. They plan on allowing water to trickle over the lightened landscape so it freezes and starts rebuilding a glacier. They are already seeing ice formation, but the plan has been met with skepticism.


    Water courses down the nets where it is captured in gutters and stored in tanks. It falls by gravity, irrigating tree saplings, and then continues through a sand filter after which it can be used by the community. The fog water collected is more than sufficient for the tree nursery but not enough for everyone's daily needs—currently a meager 10 to 15 liters per person. For that they must wait until their cloud forest has grown enough to make the nets redundant.

    Fog collecting is not a new idea: Indigenous cultures from Europe to Africa have exploited the natural fog-harvesting properties of trees to catch their water. In the Spanish Canary Islands, for example, people used to construct funnels at the base of trees to collect the fog runoff.

    Alimón biologist Kai Tiedemann spent a decade researching the fog-harvesting properties of various Canary Island trees. “From walking through a forest, it's possible to see that some trees harvest fog—they are dripping—whereas others are dry,” Tiedemann says. He tested several types of trees and bushes, hanging the branches from a line suspended in the coastal fog and measuring the volume of water produced by each. “The ones with needlelike [rather than broad] leaves were the best fog harvesters,” and those with leaves oriented vertically rather than horizontally were the best, he explains.

    Certain trees are highly adapted to harvest fog water—some, like the Californian redwood trees, satisfy the majority of their water needs in this way. The trees create a physical barrier that intercepts and precipitates fog that would otherwise rise and dissipate in the warm air. In doing so, the trees create a localized water cycle: The fog water collected on leaves drips down and nourishes grasses, shrubs, and other plants that in turn trap their own water. All this dripping water sinks into the ground, filling wells and giving rise to small streams that people can use.

    The technique works. In the 1800s, British naturalist Charles Darwin helped to make the dry, volcanic Ascension Island habitable for British troops stationed there by foresting a hill with seedlings brought from botanic gardens in London. In 20 years, there was enough water to grow food for hundreds of troops. “The once-barren hill is now known as ‘Green Mountain,’” says ecologist David Wilkinson of Liverpool John Moores University in the United Kingdom, who is an expert on the island's ecosystem. “This experiment shows that such an ecosystem that would normally take millions of years to develop can be created in a matter of decades.”

    Urban forestry.

    Residents of this slum settlement are hoping to use fog water to reforest the hill above their homes.


    Tiedemann and his partner Anne Lummerich decided to try this approach in the bone-dry outskirts of Lima. They selected a native species, Caesalpinia spinosa (“tara” in Spanish), for planting. It was the second-best collector among four they tested, but it is commercially valuable, so it offers two benefits: to harvest fog water and to produce fruit that could generate new income for the community. Tara fruit is used to produce an organic acid for the tire, tanning, and herbal medicine industries.

    Other organizations are also proposing fog-harvesting projects, with plans for as many as 20 nets in some Lima communities. There is some debate over which nets are the best design. Robert Schemenauer, who heads the Canadian nonprofit FogQuest based in Vancouver, pioneered fog harvesting with a small experiment in the Chilean desert some 20 years ago. He developed the Standard Fog Collector, a simple, double-layer net system (double so as to improve drainage), used by Luna's community, which removes 60% of the water in the air that hits it. Schemenauer's model is now being used in projects in Oman, Namibia, Guatemala, and elsewhere.

    Lummerich and Tiedemann now say they have improved on Schemenauer's standard model. Alimón's latest Eiffel Tower design, located above a community near Luna's, is a three-dimensional system. The double layer is separated by strips of netting oriented 90 degrees to the main nets, capturing fog from the different wind directions. With this model, they say, each net achieves a yield of 300 liters per day, averaged over a year, and a best yield that tops 2650 liters per day, six times the yield of the Standard Fog Collector model—something Schemenauer disputes as “impossible.”

    This July, at an international congress on fog research and fog collection, held in Münster, Germany, several new designs were pitched. They included a hexagonal “bee hive” system that can be lived in, an enhanced natural net fiber, and a Buckminster Fuller–inspired design.

    No matter what the net design, this technology may not be the long-term solution that thirsty Lima residents yearn for, however. “Fog harvesting will only provide for people's drinking, washing, and small-scale agricultural needs,” says Schemenauer. Once a community gets large enough to support businesses, such as cafes, swimming pools, and so on, the per capita daily water use goes up from about 45 liters per person to hundreds. Then, governments need to invest in piped water supply.

    And fog nets won't work just anywhere. On the Peru-Chile coast, nets must face the prevailing wind 500 to 700 meters above sea level and 5 to 10 kilometers inland to be most effective.

    Finally, climate change brings more uncertainty. Typically, the ocean-warming phenomenon of El Niño, which occurs off the Pacific coast at roughly 5- to 7-year intervals, leads to more fog. But as these episodes become more intense in the future, scientists are divided over whether they will bring more fog or less. It could be less because the fog-carrying air may be so warm that the fog droplets will be too small to be captured by the nets, and the moist air will rise too high for the nets.

    For the moment, however, Luna is betting that watering trees might just solve his water problem.

  12. Archaeology

    Using Old Insects to Sleuth Out New Clues to Ancient Cultures

    1. Heather Pringle*
    Lords of the flies.

    A Moche image shows insects hovering over prisoners being led to sacrifice.


    Criminal investigators have long recognized that insects can help solve crimes. As early as 1247 C.E., Chinese writer Sung T'zu described in a text how a magistrate solved the case of a peasant slain with a sickle. The magistrate lined up the suspects on a sunny day and asked each man to lay his sickle on the ground. As the magistrate waited, blowflies began swarming on one man's blade. Strongly attracted to carrion, the flies had detected traces of blood adhering to the murder weapon.

    Today, entomologists routinely analyze insects at crime scenes to assist police. Now a wave of new studies extends this detective power back to the ancient past. Archaeologists studying diverse times and places are finding that insects can reveal details of ancient life available from no other source. By applying their knowledge of insect biology and behavior, entomologists have helped archaeologists to reconstruct the mortuary practices of the Moche in Peru, illuminate the sanitary—or unsanitary—conditions of an ancient Egyptian city, detail the environment of early humans in Britain 780,000 years ago, and probe the possibility of very early agriculture in Japan 9000 years ago. These new studies by no means exhaust the possibilities, says entomologist and forensic anthropologist Robert Pickering of Gilcrease Museum in Tulsa, Oklahoma. “Wherever people have been, there was an insect community either on them or with them,” he says. “By studying these insects we can create a clearer picture of the past.”

    In a grisly example published in this month's issue of the Journal of Archaeological Science, archaeoentomologist Jean-Bernard Huchet of the University of Bordeaux 1 in France and entomologist Bernard Greenberg of the University of Illinois, Chicago, identified 1700-year-old fly remains to understand how the Moche people treated their dead. The Moche were largely maize agriculturalists who flourished between 100 C.E. and 700 C.E. and are known for depictions of human sacrifice in their art. Skeletal remains suggested that the Moche developed complex mortuary rituals, including delayed burials and reopened graves.

    To probe such rituals, researchers analyzed insect remains. While excavating 57 graves at the site of Huaca de la Luna on Peru's north coast, CNRS archaeologist Claude Chauchat of the University of Paris in Nanterre found hundreds of small, barrel-shaped casings, each of which once protected an insect pupa. Chauchat asked Huchet to identify nearly 200 puparia and other insect remains found in the grave of a young adult male who died between 1700 and 1900 years ago. “This was the grave richest in insects,” says Huchet, “with a lot of diversity of species.”

    Plenty of pupae.

    Insect casings left in a grave more than 1700 years ago reveal the complex mortuary rites of Peru's Moche culture.


    Huchet and Greenberg examined each puparium with a scanning electron microscope and compared diagnostic features—such as the contours of the respiratory slit—with those of known Peruvian species. The casings belonged to three taxa: houseflies (Muscidae); blowflies (Calliphoridae); and flesh flies (Sarcophagidae). Huchet also identified a fragment belonging to the Trogidae, or carcass beetles, and determined that parasitic wasps hatched in some puparia.

    He then gathered published data on the life history of these species. To find out when previously unstudied species began breeding on carrion, he conducted experiments in Peru by leaving out chunks of pork. Several of the flies had different timetables. One blowfly, for example, preferred laying eggs on the newly dead, whereas a certain species of housefly favored breeding on rotting, 2-week-old carcasses. The team drew up a timeline for insect succession on the ancient cadaver and concluded that the body had lain in the open for 1 month.

    Why did the Moche hold off burying the dead? Huchet thinks they wanted to attract certain flies and their flesh-eating larvae as a way of releasing the human spirit after death, a practice followed by later Andean peoples. During the 17th century, indigenous Peruvians told a Spanish chronicler that “the cadaver must be left long enough to breed worms [fly larvae] so its anima can emerge and escape in the form of flies.” The idea fits well with Moche iconography. One surviving Moche ceramic bottle, for example, depicts hovering flies as Moche warriors led male prisoners off for sacrifice (see image, above).

    The Moche burials are “like a detective case,” says physical anthropologist John Verano of Tulane University in New Orleans, Louisiana, “and Huchet is opening the door to a more nuanced reading of the dead.” The findings are “both dramatic and convincing,” agrees University of Bordeaux anthropologist Henri Duday, and point to “all the progress we can now expect” from studies of insects.

    Taking out the trash in Amarna

    As studies of insects mature, they may complement—or contradict—other kinds of data. For example, tomb paintings depict the ancient Egyptian city of Amarna, founded in 1353 B.C.E. by the pharaoh Akhenaten, as a healthy, well-organized place. Archaeologists have even found a kind of landfill there, suggesting some form of organized trash disposal. But insect remains examined by paleoentomologist Eva Panagiotakopulu of the University of Edinburgh in the United Kingdom and her colleagues reveal a far more casual approach to garbage.

    Archaeologists working in an affluent part of Amarna recovered insect remains and plant debris from deposits sandwiched between two house floors. The lower floor belonged to a small early house, but the upper floor was part of a large dwelling owned by Akhenaten's chief charioteer, Ranefer, mentioned in door-post inscriptions. Because the area between the floors was sealed, the insects must have been deposited in the 25 years or so that Amarna was occupied.

    In work published in the Journal of Archaeological Science in October 2009, Panagiotakopulu and Paul Buckland, a private paleoentomologist, identified 37 insect taxa from fragments of exoskeletons, puparia, and desiccated larvae. The beetles were largely pests of stored cereal grains, suggesting that someone had dumped badly infested grain on the first house floor. The researchers also found traces of swarming, breeding flies, mostly the housefly Musca domestica, which frequents “foul and dirty areas, especially when found in large numbers,” says Panagiotakopulu. The team also identified two beetle species that feed on teeming maggots.

    To archaeologist Paul Nicholson of Cardiff University in the United Kingdom, the data strongly suggest that local residents threw their garbage into the early house after it was abandoned and before Ranefer built there. “It looks as if some of the refuse was just taken out and dumped,” says Nicholson, “so there must have been some really quite unpleasant areas in ancient Egyptian towns.”

    In other cases, insects may offer details that fit with other evidence. For example, a well-preserved insect assemblage recently helped to reconstruct the ancient environment at Happisburgh Site 3 in England, occupied by early humans sometime between 780,000 and 1 million years ago. Previous evidence had suggested that hominins expanded into northwest Europe only when a warm, Mediterranean climate prevailed there. But paleoentomologist G. Russell Coope of the University of Birmingham, working with team leader Simon Parfitt of University College London, found that although most of the nearly 150 beetle species from Happisburgh samples were temperate species, a few inhabited boreal forests.

    Early pests.

    Microscopy (top) and CT scanning (above) show traces of maize weevils (center) in Japanese pots at least 9000 years old.


    Coope then examined the modern climatic ranges of 34 of the species and calculated summer and winter temperatures in the overlap zone. He concluded that the mean temperature in Happisburgh's coldest month fell to −3°C—colder than today. Such data give a far more local picture of climate than those obtained from oxygen isotope records found in ocean sediments, Coope says.

    Together with other environmental data, Coope's work indicates that Happisburgh's early hominins ranged across a region whose climate was similar to that of southern Scandinavia today. So “early Paleolithic humans were either a damn sight more sophisticated than we thought, being able to tolerate such cold conditions,” Coope says, “or alternatively, they could have been migratory, moving north only during the summer.”

    Insect traces are also hinting at precocious human capabilities in a completely different time and place: an early Holocene site in Japan. Researchers studying 4000-year-old potsherds made by the ancient Jomon people have found tiny holes in the clay made by maize weevils, which commonly infest stored rice and barley today. More recently, a team led by archaeologist Hiroki Obata of Kumamoto University in Japan found seven such weevil-shaped cavities, each only about 3 millimeters long, in charcoal-bearing potsherds dated all the way back to 9000 years ago at Sanbonmatsu in southern Japan; unpublished data suggests the sherds may be even older.

    In work announced in Nature Precedings in May 2010, Obata and his team injected each weevil hole with silicone to make a cast of the insect, which apparently got into the wet clay as the pot was being made. Scanning electron microscopy photographs and computed tomography scans suggest that the insect casts were those of maize weevils. “We were very surprised to find the oldest maize weevils,” says team member Aya Manabe of Kumamoto University.

    But what were these weevils eating so long ago? The earliest widely accepted evidence for rice cultivation in Japan is rice phytoliths that date only to 4000 to 3000 years ago. So Obata and his team suggest that Sanbonmatsu's weevils infested stores of wild foods, such as bamboo seeds or acorns.

    Other researchers aren't so sure. Sanbonmatsu lies in “an area of Jomon precocity,” says archaeologist Richard Pearson of the University of British Columbia, Vancouver, in Canada. As early as 11,000 years ago, Jomon families there resided in large villages and relied heavily on plant foods, as shown by an abundance of grinding stones. It's possible that this precocity was fueled by some kind of early horticulture, says Pearson. “More evidence is clearly necessary,” he adds.

    Whatever the Jomon people and their weevils were eating, entomologists agree that the surge of interest in very old insects bodes well for studies of the past. “I'm just staggered,” Coope concludes, “by what can be done with insects in archaeology.”

    • * Heather Pringle is a contributing editor at Archaeology magazine.

Log in to view full text

Via your Institution

Log in through your institution

Log in through your institution