Signal and noise

The largest of the telescopes in the hunt— the Low Frequency Array, or LOFAR—bristles in the middle of a peat bog in the north- ern Netherlands. One of its creators, co– principal investigator (PI) Michiel Brentjens of ASTRON, the Netherlands Institute for Radio Astronomy, in Dwingeloo, calls it “the most unimpressive radio telescope in the world.” He’s right: It’s just a thicket of hundreds of white plastic poles about the height of a person, braced by guy ropes. The guys are the antennas, no different in prin- ciple from a rooftop TV antenna. Large low boxes under tarpaulin covers contain more, smaller antennas. A few scattered electrical cabinets hum ominously.
LOFAR is an interferometer, a device that combines signals from widely spaced detec- tors to extract information from the differ- ences between them. The core of the array

But the location of LOFAR is far from ideal. The Dutch government provided €53 million to build the array so long as its core was sited in the north of the country to help build up high-tech infrastructure there. Besides the boggy terrain, LOFAR has to contend with interference from nearby radio sources, including the 88-to-108 megahertz band of FM broadcasts, which are slap in the middle of the frequencies LOFAR is trying to detect. “The signals from all the radio and TV transmitters in [the FM] band are just phenomenal,” says LOFAR PI Ger de Bruyn of ASTRON. “They’re a million times brighter [than the EoR signal], so you can’t observe there.” Fortunately, the team found that the main hunting ground for EoR signals, about 150 MHz, “seemed to be very quiet,” he says.
The other main arrays are sensibly situ- ated in remote radio-quiet areas. The Precision Array for Probing the Epoch of Reionization (PAPER)—Backer’s brainchild— is in the semidesert Karoo region of South Africa. Its garden chair–like antennas have been growing in number since 2009 and have now reached 128. The third instru- ment, MWA, sits on the semiarid plains of Western Australia, a few hundred kilo- meters north of Perth. MWA was instigated by a group of U.S. institutions that were originally part of the LOFAR project. They parted company with the Dutch over the is- sue of building LOFAR in the noisy environ- ment of the Netherlands and set out to build their own array, teaming up with research- ers in Australia, New Zealand, and India. The resulting telescope has 2048 spider- like antennas arranged in 128 four-by-four tiles. “It’s in good shape and running well,” Bowman says.

But building the arrays is, in a sense, the easy part. The antennas are “old tech- nology,” says theorist Saleem Zaroubi of the University of Groningen in the Neth- erlands, a co-PI on LOFAR. They have no moving parts and so cannot focus on a particular spot—they simply pick up every- thing coming from the sky. It falls to dis- tant supercomputers to make sense of the signals, processing them to calibrate the instrument, focus on a part of the sky, and separate the signal from the noise. Such “software telescopes” offer the advantage of becoming more powerful as computers do, even without changes to the antennas on the ground.

The biggest challenge the arrays face is picking out the extremely feeble EoR sig- nal from all the other radio sources at the same frequency. In our Milky Way galaxy, radio waves at those frequencies come from sources including supernova rem- nants, charged particles accelerated by the galaxy’s own magnetic field, and radiation from electrons colliding with ions inside hydrogen clouds. Outside the Milky Way, countless radio galaxies and galaxy clusters also broadcast their own signals. Models of the EoR signal suggest that these other ra- dio sources are between 1000 and 100,000 times brighter—which means astronomers 

Genetics may foster bugs that keep you thin

Twin study shows genes influence gut micro biome

Gut microbes are soldiers in the battle
of the bulge, researchers have learned in the past few years, with some or- ganisms seeming to promote thin- ness and others triggering weight gain. The makeup of such microbes

is known to be influenced by a person’s diet and environment. Now, a study of twins shows that genetics can also provide an edge in the microbial battle. Researchers identi- fied a microbe that appears to keep waist- lines trim—and found that genes influence its abundance. “It’s the first really strong evidence that human gut microbiology is genetically controlled,” says geneticist Oluf Pedersen of the University of Copenhagen, who wasn’t involved in the study.
The work, published in the 6 November issue of Cell, raises hopes for microbial treat- ments for obesity. But microbial ecologist Ruth Ley of Cornell University and her col- leagues originally wanted to answer a more basic question: Do genes affect the makeup of the gut microbiome? Like many research- ers trying to distinguish environmental from inherited influences, they turned to twins. Working with colleagues running a large-scale project called TwinsUK, the team collected more than 1000 stool sam- ples from 171 identical and 245 fraternal pairs of twins, as well as 173 samples from unrelated individuals. Among these people,322 were overweight and 183 were obese. Previous twin studies had failed to identify a genetic connection to microbiome diver- sity and abundance, but those studies looked at the microbiome as a whole. The new study instead takes a species-by-species approach. By sequencing and analyzing DNA from the fecal samples, Cornell graduate student Julia Goodrich and her colleagues found more than 9600 genetically distinct micro- bial “species.” Most microbes varied accord- ing to environmental factors, but some were apparently influenced by genetics, because they were more similar in identical twins than in fraternal twins. The genetic makeup of these twins may affect gut physiology or biochemistry in a way that favors the growth of some microbes over others, the researchers suggest.

The microbes most strongly affected by genes belong to a recently discovered, rather obscure family of bacteria called Christensenellaceae. To the researchers’ surprise, this family was most abundant in lean twins and rare in obese ones. To see how the microbes might influence weight, Ley and her team transferred fecal material from lean and obese twins into germ-free mice. The weight gain in the mice mirrored that of the humans donating the feces. And when Goodrich supplemented feces from obese twins with one of the microbes, Christensenella minuta, and gave them to mice, the mice stayed lean. The microbe “has some aspect of being able to influence weight,” says Cornell geneticist and co-author Andrew Clark.
“We want to see if [the microbe] can be developed as a probiotic for helping people maintain their weight once they’ve lost it,” Ley says. But she and her colleagues first need to figure out how C. minuta exerts its effects and whether such a treatment would work only in people genetically dis- posed to supporting it. At this point, says Nita Salzman, a pathologist at the Medi- cal College of Wisconsin in Milwaukee, to think about a probiotic “is almost certainly an oversimplification.” ■ 

An Internet research project draws conservative ire

Truthy project at Indiana University analyzes Twitter traffic to understand patterns of political discourse 

The truth about Truthy has become a
scarce commodity.
Truthy is a 4-year-old academic study of how information spreads on Twitter. The work, by researchers at Indiana University (IU), Bloomington, has been cited favorably in mainstream media reports about the broader phenom- enon of online memes—messages about ideas, issues, and events—and the role they can play in ev- erything from shaping protest movements to signaling out- breaks of disease. But recently the Indiana project fell afoul of another Internet phenom- enon—how some messages can spread even if they are not correct.
In the past few months, Truthy has become the target of wither- ing attacks from conservative bloggers and politicians. In particular, they have char- acterized a 4-year, $920,000 grant the sci- entists received in 2011 from the National Science Foundation (NSF) as an attempt by the U.S. government to monitor and restrict free speech. The attacks are “not simply a misunderstanding of our research,” says  computer scientist Filippo Menczer, the principal investigator on the NSF grant. They are “a deliberate attempt to distort what we have done.”

Menczer’s work, which is also supported by the military’s Defense Advanced Research Projects Agency and by the private James S. McDonnell Foundation, is rooted in the growing field of complex, nonlinear feed- back systems. “It has become a very hot topic of research,” notes Menczer, who is the director of IU’s Center for Complex Networks and Systems Research. The field includes studies of natural systems such as planetary orbits and climate—and also social ones, such as the spread of information on Twitter. Twit- ter itself has begun awarding grants to aca- demics who want to study its daily torrent of more than half a billion tweets.
Under the NSF grant, Menczer and his colleagues have studied Twitter messages to shed light on the nature of social dis- course. Some of their early work on U.S. po- litical debate, for example, found evidence of a growing polarization, in which people communicate mostly with those who hold similar views on any particular issue rather than trying to engage those who disagree with them. More recently, the researchers’ examination of the 2013 protests against the Turkish government found that the movement became more democratic over time, with a growing number of people shaping the direction of the protest. The re- searchers also hope to learn how to differ- entiate memes spread by real people from those broadcast by automated software, a technique used by some businesses and advocacy groups to create the illusion of a groundswell of public interest in an issue.

This summer, Truthy itself fell under scrutiny, starting with a 25 August piece in The Washington Free Beacon, a con- servative online news website. Its head- line proclaimed that the U.S. government is “Creating [a] Database to Track ‘Hate Speech’ on Twitter.” Within days, several conservative commentators jumped on the anti-Truthy bandwagon. “So some bureau- crat decides whether you are being hateful or misinforming people—what could pos- sibly go wrong?” a reporter for Fox News asked sarcastically.
Elizabeth Harrington, who wrote the Free Beacon story, says she was just doing her job. “One of the areas that I cover is how government is spending taxpayers’ money, and I found this grant interesting,” she ex- plains. “The whole premise of the project struck me as questionable, and I hadn’t seen any other coverage of this aspect of the research.” Many of the critical stories quote selectively from a Truthy grant abstract on NSF’s website to argue that the research is an example of the Obama adminis- tration’s targeting of conserva- tives. The Free Beacon story, for example, says NSF “is financing the creation of a web service that will monitor ‘suspicious memes’and what it considers ‘false and misleading ideas,’ with a major focus on political activ- ity online.” But those phrases actually apply to an online platform that the researchers created to give the public a chance to com- ment on anything being tweeted. The sci- entists weren’t deciding which tweets were “suspicious,” nor targeting any particular ideological position.

 “The headlines are saying something that is completely false and fabricated,” Menczer told the Columbia Journalism Re- view, which covered the flap in September. “We are not defining hate speech. We are not tracking people. We don’t have a database.” New findings are posted regularly on the project’s website and written up in regular academic journals, he explained, and noth- ing is being secretly funneled to a govern- ment agency for some nefarious purpose.

Even so, conservative commenters have continued to pillory the work. A 17 October op-ed in The Washington Post by Ajit Pai, one of two Republicans on the five-member Fed- eral Communications Commission, called the project an attempt “to squint for and squelch” political comments. “The federal government has no business spending your hard-earned money on a project to monitor political speech on Twitter,” Pai asserted.
Senior Republican lawmakers are also suspicious of Truthy. Representative Lamar Smith (R–TX), the chair of the science com- mittee in the U.S. House of Representa- tives, said he’s adding the grant to his list of questionable research projects that NSF has funded over the years (Science, 10 Octo- ber, p. 152). “[T]his one appears to be worse than a simple misuse of public funds,” Smith said in a 21 October press release.
Truthy takes its name from “truthiness,” a word satirist Stephen Colbert invented for his television show, The Colbert Report. In a 2006 interview, Colbert explained why he coined the word. “It used to be, everyone was entitled to their own opinion, but not their own facts,” Colbert noted. “But that’s not the case anymore. Facts matter not at all. Perception is everything. It’s certainty [that counts].”
Ironically, the NSF solicitation for the program that is funding Menczer’s team notes that the growth of social media may aggravate social conflict because it offers a common platform to “parties who may not know or trust each other.” Those conflicts can easily snowball online, the program so- licitation noted.
NSF officials warned Menczer that at- tempting to defend himself could backfire, he notes. “They said, ‘Be very careful. You don’t want to talk about politics. That’s not what you do.’ ” Even so, the Truthy research- ers have posted a running rebuttal on their website, including what the project is and isn’t, and Menczer says he’s willing to speak with those he views as “bona fide reporters who want to know about my work.”

The team’s current NSF grant ends next summer, and Menczer isn’t sure if he’ll sub- mit a new proposal to the agency. But if he does, he predicts that “we will probably stay away from anything to do with politics.” ■ 

Delays hinder Ebola genomics

For months, no sequences from the virus have been released

as the Ebola epidemic sweeps through
West Africa, scientists lack key ge- netic data to answer a question that has provoked much worried specu- lation: Is the virus becoming more transmissible or more deadly, or ac-
quiring changes that would let it evade diag- nostic tests or vaccines? Thousands of blood samples from Ebola patients have been sit- ting in refrigerators in Africa and Europe, untouched. And, as Science went to press, the few groups that have new sequence data have not made them public.
Researchers are eager for a close-up look at how the virus may be evolving. Besides answering questions about its virulence, genomic data could reveal details about the epidemic, including hotspots of trans- mission and how often the virus has escaped from its animal reservoir to humans, says Andrew Rambaut, an evolutionary biologist who studies infectious diseases at the Uni- versity of Edinburgh in the United Kingdom. “If it can be done on a timely basis, you can really get insight into what is going on.” But faced with the all-consuming public health response to the epidemic, bureaucratic obstacles, and chaotic record keeping, scien- tists have had to wait.

In August, the world got its closest mo- lecular look at the virus so far, when re- searchers published 99 genomes of viruses from 78 patients who were infected in or around Kenema, Sierra Leone, from late May to mid-June. That analysis, published online on 28 August in Science, included more than half of the known cases in Sierra Leone at the time.
The sequence data, which the researchers deposited in public databases as soon as they were generated, showed how the virus changed as it passed from person to person at the start of the Si- erra Leone outbreak, with one variant dis- appearing as another gained  rominence among later cases. Since then, the outbreak has exploded into an epidemic—it has now sickened more than 13,000 and killed 5000—but the team, led by Pardis Sabeti and Stephen Gire at the Broad Institute in Cam- bridge, Massachusetts, has been unable to import any new samples from Sierra Leone. 

Other groups have been similarly stymied. Several researchers say that getting export approval from beleaguered health ministries has been tough. “I can only assume that the system is so overwhelmed that processing samples beyond simple diagnostic tests is not high priority,” says Rambaut, who was a co-author on the August sequence paper. Stephan Günther, a virologist at the Ber- nhard Nocht Institute for Tropical Medicine (BNI) in Hamburg, Germany, and coordi- nator of the European Mobile Laboratory (EMLab) consortium, says they have been unable to export samples from Nigeria or Liberia. But BNI has been receiving samples from the EMLab mis- sion in Guinea since March and now has close to 3000, he says. (BNI is storing them in its high-security lab on behalf of the Guinean government, which

still owns them.) Günther and his col-
leagues have not yet sequenced any of the samples, because consortium staff members have been busy supporting diagnostic cen- ters in affected countries. “We are all busy with fieldwork,” Günther says. “Personnel is a bit of a problem.” That should ease, he says, with a new €1.7 million ($2.1 million) award from the European Union to EMLab for Ebola research.
In France, the Institut Pasteur, where early samples from Guinea were first iden- tified as Ebola, also experienced delays exporting samples from West Africa but plans to start sequencing new viral ge- nomes soon. The institute’s lab in Dakar recently received samples from Guinea, says Felix Rey, who is coordinating the institute’s Ebola task force in Paris. The Dakar lab will extract RNA and send it to Paris for high-throughput sequencing. “We hope to have sequenced viruses from
a couple of hundred samples in the next month or so,” Rey says.

Sabeti and her colleagues should soon get their Sierra Leone samples, which finally were cleared for export and arrived in the United States last week, says Robert Garry of Tu- lane University in New Orleans, Louisiana, who collaborates with Sabeti. But to speed the research, she and her colleagues are try- ing to secure funding to send se- quencing machines to West Africa. “If we can’t get the samples here, we will get the sequencers there,” she says. The effort will build on the researchers’ ongoing work with the African Centre of Excellence for Genomics of Infectious Diseases, a consortium of universities and research institutes in the United States, Nigeria, Sierra Leone, and Senegal, which for several years has been training African researchers in the use of genomics tools.

Blood samples alone aren’t enough for genomic studies. Investigators need to know at least where each patient was from; ideally they will also have clinical information such as whether he or she survived. “Only when you have those pieces of information can you come up with useful information from the sequences,” Günther says—and because of spotty record keeping, that information is often missing. He and his colleagues are working with Doctors Without Borders and the World Health Organization to match samples with relevant information, but set- ting up a database is time- and labor-inten- sive, he says.
Meanwhile, the few Ebola virus sequences that have been generated since that ini- tial batch from Sierra Leone have not been made public. The U.S. Centers for Disease Control and Prevention (CDC) announced in August that it had sequenced Ebola virus samples from patients treated in the United States. But the data have not been placed in any public sequence repositories. That’s un- fortunate, Rambaut says. “As the U.S. cases are from Liberia and we have zero sequences from there so far, even one genome would be interesting and potentially useful,” he says. Duncan MacCannell, a bioinformat- ics specialist at CDC in Atlanta, told Science that the sequences had been “actively shared and discussed with the public health com- munity.” He says CDC is working to submit the sequences to a public database.
New sequences probably won’t show that the virus is finding new ways to attack or spread, Rambaut says. Instead, the prize is a clearer picture of the outbreak. A cluster of closely related viruses might point to a hotspot of transmission, he says, while un- expectedly diverse sequences would suggest that many cases were going undetected. Sequence data could also help researchers tell whether there has been more than one animal-to-human introduction.

Earlier sequence data did suggest that the virus was undergoing rapid changes, but that is not necessarily a sign that it is becoming more dangerous, Rambaut says. “Most RNA viruses mutate quickly, but ad- aptation and functional change is a much slower process.” Measles mutates nearly as quickly as Ebola virus, but it has never evolved to escape the lifelong immunity of previously infected or vaccinated individu- als. Even in an outbreak this big, Rambaut says, “I see no reason to suspect the virus will radically change its life cycle or its mode of transmission.” ■ 

What’s killing the reindeer?

Conservationists and herders in Norway differ about whether to blame predators or overpopulation 

An ecologist’s study of reindeer has touched off a firestorm in this land of ice, tundra, and Sami herders, who tend vast numbers of the semi- domesticated animals. Each year, the herders file compensation claims for tens of thousands of reindeer deaths that they blame on carnivores, primarily lynx and wolverines. Ecologist Torkild Tveraa, how- ever, pins the blame on overpopulation: The land simply cannot support the herds, which number roughly 180,000 here in Finnmark, Norway’s most northern region.

Tveraa, who is with the Norwegian In- stitute for Nature Research in Tromsø, first presented his case in a government-funded report last year, and he added new analysis in a study published in the October issue of the Journal of Applied Ecology. The govern- ment has pointed to the findings as exoner- ating the threatened lynx and wolverines, which are already protected by strict hunt- ing limits. To the Sami, however, the study threatens an economic lifeline.
To receive compensation, a herder must prove that a dead reindeer was killed by a lynx or wolverine. That’s hard when herd- ers find remains of only 5% to 10% of the reindeer that they lose. The government ap- proved just a quarter of more than 60,000 such applications in 2011. The claims none- theless are lucrative: That year, Sami herders in Norway received $11 million in predator payments, or two-thirds of what they re- ceived from meat sales.
To find out how much damage the preda- tors really do, Tveraa’s team combined their own data on reindeer health since 2000 with herd sizes reported by herders, obser-

vations of lynx and wolverines, and satellite data on grazing areas. They found that as a factor in reindeer mortality, food scarcity was two to three times more significant than lynx, and more than 20 times more significant than wolverines.
“Tveraa has a very solid basis for these findings—a very large data set collected over a very long time series,” says Terje Bø, head of wildlife management in the Norwe- gian government’s environment division in Trondheim. In the global canon of human- carnivore conflict research, Tveraa’s “robust” study, says Matt Hayward, an ecologist at Bangor University in the United Kingdom, “goes against the grain of papers saying, ‘It’s the predators’ fault.’ ” Other experts agree that the findings are plausible. “It’s sort of official: We have too many reindeer,” says Emil Halvorsrud, a wildlife official in Lak- selv. Large herds are becoming less sustain- able, he says, as a warming subarctic climate results in more slush and rain in winter, leaving pastures covered in ice.
Ellinor Jåma, with the Sami Reindeer Herders’ Association of Norway in Karasjok, agrees that overpopulation is a factor in some deaths. “We may have too many reindeer in some areas of Finnmark,” she concedes. “But in the middle of the country, reindeer health is good—and we still have heavy losses,” which she blames on predation.
Bø hopes Tveraa’s findings will show how ecological data could underpin a new com- pensation system the government has pro- posed to launch in 2017. Tveraa underscores that he doesn’t take sides in the debate. “We hear: ‘Oh, since your research is paid for by the government, you are only there to pro- tect the carnivores,’ ” he says. That’s not so, he insists: “The data speak for themselves.” ■ 

Plan to protect Great Barrier Reef under fire

Continuingdegradationthreatensreef’sWorldHeritageSitestatus

atralia’s Great Barrier Reef is un- der assault from fishers, agricultural runoff, and coastal development, and now climate change looms as a threat. But it was the prospect of humiliation—a threat by the World Heritage Committee to list the reef as “in danger”—that finally spurred the Australian government to act. It has crafted what it calls a comprehensive strategy to protect the reef ’s “values” while allowing “sustainable development and use.” Scientists who have reviewed the draft plan are not impressed.
The plan “fails to effectively address” any of the pressures the reef is facing, according to a statement last week from the Austra- lian Academy of Science, which argued that “much bolder action is required” to prevent further degradation. Scientists hope the government will considerably strengthen the Reef 2050 Long-Term Sustainability Plan before submitting it to the World Heri- tage Committee early next year.
Australia created the 344,400-square- kilometer Great Barrier Reef Marine Park off the state of Queensland in 1975, along with a Marine Park Authority to protect it. Conservation efforts were bolstered in 1981, after the reef was designated a World Heri- tage Site in recognition of its “outstanding universal value.”
Yet conditions at the reef have deterio- rated. In a 2012 report in the Proceedings of the National Academy of Sciences, Glenn De’ath of the Australian Institute of Ma- rine Science in Townsville and colleagues reported that the reef’s coral cover shrunk

by half between 1985 and 2012. The cul- prits, De’ath’s group found, were cyclones, predation by crown-of-thorns starfish, and bleaching—loss of the coral’s photo- synthetic organisms when the water gets too warm. “Without intervention,” the team warned, “the GBR may lose the biodiversity and ecological integrity for which it was listed as a World Heritage Area.”
The Great Barrier Reef ’s decline has alarmed scientists around the world. “The fact that a very well managed reef system is still showing substantial deterioration should be cause for general concern, be- cause it reveals how pervasive our impacts are and how serious the consequences are for coral reefs,” says Peter Sale, a reef ecolo- gist and professor emeritus at the University of Windsor in Canada. It has also alarmed the World Heritage Committee, which warned last summer that in the absence of a long-term plan by early next year, it would consider listing the reef as “in danger.” That “would be such a public shame for Austra- lia,” says Selina Ward, a reef ecologist at the University of Queensland, St. Lucia.
The draft 2050 plan acknowledges that more work is needed to address threats to the reef and calls for targets on water quality, biodiversity, ecosystem health, and economic and community benefits. But the academy points out that “many important targets are not quantified, nor are they con- nected to any mechanisms through which they can be achieved.” The Australian Coral Reef Society adds that the plan anticipates port expansion and dredging and sets an objective of completing such work with “no detrimental impact on the health and resil-

ience of the Great Barrier Reef.” However, states the society, “There is no indication of the method to achieve this ambitious objec- tive.” Nor, states the Australian Museum, does the plan address “the long term viabil- ity of fisheries and endangered species.”
For a long-term conservation strategy, the plan pays little attention to climate change, says Terry Hughes, director of the ARC Cen- tre of Excellence for Coral Reef Studies in Townsville. It notes that climate change will lead to more frequent bleaching and extreme weather events. But it doesn’t offer any so- lutions, Hughes says. Earlier this year, the Australian government repealed the nation’s carbon tax and is promoting the development of coal deposits for export from Queensland.
The Australian government says it is lis- tening to critics, but hasn’t tipped its hand on how it may revise the plan. “We appreci- ate community engagement in how we can better manage the reef,” wrote an environ- ment ministry representative in an e-mail to Science. He did note that “the plan ac- knowledges that climate change is a global problem which requires global action, and is being addressed by the government through other policies.”

“We hope that the government will im- prove the plan, and we’d like to help with that,” Hughes says. A final plan must be submitted to the World Heritage Commit- tee by 1 February, after which an advisory panel will review it and present a recom- mendation at the committee’s annual meet- ing in Bonn in June. At a 2 October press conference, Environment Minister Greg Hunt said he’s “optimistic” the committee will maintain the reef’s current status. ■ 

Petition for jailed student

An open letter signed by 31 Nobel laureates that calls for the release of jailed Iranian physics Ph.D. student Omid Kokabee was delivered to the Iranian mission to the United Nations last week, along with earlier petitions signed by more than 14,000 people. Kokabee, 32, has been in prison since January 2011 (http://scim.ag/ Kokabeetrial). 
He was studying the interaction of lasers and plasma at the University of Texas, Austin, when he was arrested and was later condemned to 10 years for espionage. In April 2013, Kokabee claimed in an open letter that he was jailed for refusing to cooperate with a military research project. In early October, Iran’s supreme court accepted Kokabee’s lawyer’s appeal and ordered
a retrial. Kokabee was also awarded the AAAS Scientific Freedom and Responsibility prize last week. (AAAS publishes Science.)
Italian physicist to lead CERN
Fabiola Gianotti will be the next director- general of CERN, the European particle physics laboratory near Geneva, Switzerland, which is home to the world’s biggest atom smasher, the Large Hadron Collider (LHC). A staff member at CERN, Gianotti, 52, served from March 2009 to February 2013 as spokeswoman for the 3000 researchers working with ATLAS, one of four gargantuan particle detectors fed by the LHC. In that position, she partici- pated in the biggest event in particle physics in decades: On 4 July 2012, she and the representative for rival detector CMS reported that the two teams had indepen- dently discovered the long-sought Higgs boson. Gianotti will take over from Rolf-Dieter Heuer on 1 January 2016. 

Vaccine may slow koalas’ decline

Help may
be on the way for koalas, whose numbers have declined from millions in the
1700s to as few as 43,000 today. In addition to urbanization, which has decimated the eucalyptus forest koalas live in, and deaths due to cars and dogs,
a chlamydia epidemic is ravaging the marsupial’s populations, causing blind- ness, infertility, and death. But last week, microbiologists at the University of the Sunshine Coast in Queensland, Australia, announced that a vaccine helps stem
the course of disease. Peter Timms and his colleagues examined and put radio collars on 60 koalas, vaccinating half
of them. Of that half, uninfected koalas were protected, koalas already infected did not get sicker, and their eye infections improved, they said. They hope to get more funding to extend the vaccination program. 

The trees and the tornado: Winner of ‘Dance Your Ph.D.’

Acircus extravaganza by plant biologist-cum-aerialist Uma Nagendra depicting plant-soil interactions in the aftermath of a tornado is the overall winner of this year’s “Dance Your Ph.D.” contest, co-sponsored by Science. Nagendra, a Ph.D. student at the University of Georgia, Athens, demonstrates how tornadoes’ destruction can offer tree seedlings a respite from parasitic soil fungi. Nagendra, also the biology category winner, will receive $1000 and a trip to Stanford University in May 2015, where her video will be screened. The three other category winners, each of whom will receive $500, include: Hans Rinderknecht of the Massachusetts Institute of Technology in Cambridge, who explained how he uses light to trigger nuclear fusion; Saioa Alvarez of the University of the Basque Country in Leioa, Spain, for her dance explaining the chemistry of emulsions like mayonnaise; and David Manzano Cosano of the Complutense University of Madrid, who danced about the history of technology and colonialism in the Pacific. http://scim.ag/DancePhD2014 

Experiments lost in rocket explosion

six seconds after liftoff, on 28 October an unmanned Antares rocket commis- sioned by NASA and bound for the International Space Station (ISS) exploded just over the launch pad at Wallops Island, Virginia. The explosion of the rocket, built by Orbital Sciences Corp., incinerated numerous scientific experiments on board as well as 748 kg of supplies for the six astronauts on the ISS. Among
the losses were 18 experiments by students from across the United States and Canada; a high-resolution camera developed by the Southwest Research Institute in San Antonio, Texas, to observe the chemical composition of meteors entering Earth’s atmosphere; and an experiment to test materials for their suitability as solar sails, which use radiation pressures from stars to propel spacecraft without burning fuel. http://scim.ag/Antaresrocket 

Astronomers are attempting to look back to when the first stars and galaxies lit up and changed the universe forever

Astronomers are attempting to look back to when the first stars and galaxies lit up and changed the universe forever

They may be the strangest tele- scopes on Earth. They have no domes, no giant mirrors, no steer- able radio dishes—just scattered arrays of simple antennas, some on poles as tall as a person, others re- sembling robot spiders or bizarre garden furniture. These antenna arrays—one in Northern Europe, one in South Africa, a third in Australia— can’t point at particular heavenly targets. Instead, they passively take in whatever sig- 

nals come their way and feed them to dis- tant supercomputers where the real work of detection is done. 

The otherworldly instruments have an otherworldly target. They are probing a time so far back in the universe’s history that there was very little to see: just a few of the very earliest stars and galaxies. And their quarry is not the scattered points of light at that early epoch, but the diffuse ocean of gas between them, where a pro- found change was taking place. 

By some 400,000 years after the big bang, the expansion of the universe had cooled the maelstrom of particles and energy formed in the instant of creation. The result was a dark fog of gas, mostly hydrogen. The universe’s “dark ages” had begun. It took many mil- lions of years for the gas, which was cool and electrically neutral, to slowly swirl together to form stars and galaxies—and when it did, the gas itself was transformed. 

The most distant galaxies astronomers can now see, about a billion years after the 

big bang, live in a universe full of ionized hydrogen—bare protons with their elec- trons stripped away. Just as the lights came on, something must have ionized all the universe’s hydrogen. The most likely cul- prits are the early stars and galaxies them- selves, but to do this they would have had to be very different from the stars and gal- axies we can see today: bigger, more violent, more exotic. Astronomers are desperate to know more—but not much can be gleaned from scattered lights in a fog more than 13 billion light-years away. 

In 1997, however, British astronomer Martin Rees and colleagues Piero Madau and Avery Meiksin suggested that astronomers look for a signal from the early neutral hy- drogen itself. In a hydrogen atom, the central proton and the orbiting electron normally have opposite magnetic orientations. When some energy source flips them into the same orientation, the atom quickly relaxes back into its ground state and emits a microwave photon, at a wavelength of 21 centimeters. 

Unlike the neutral gas, ionized hydrogen emits no such radiation. Rees et al. sug- gested that if astronomers could detect the 21-centimeter radiation from the so-called epoch of reionization (EoR), they might see radiation-free “bubbles” of ionized hydrogen around whatever was ionizing the gas. The size and distribution of those bubbles could provide information about the nature of the sources and the timing of reionization. 

Astronomers began thinking about what it would take to detect such a signal. As 21- cm radiation from the EoR travels across the universe, cosmic expansion stretches its wavelength to about 2 meters. Conven- tional radio telescopes are mostly blind to such long wavelengths, and a purpose-built dish would be impractically large. But there was another way: an array of simple anten- nas and some heavy-duty number crunch- ing. As astrophysicist Don Backer of the University of California (UC), Berkeley, said at the time: “All you need is paperclips and a supercomputer.” 

Now, several of these paperclips-and- supercomputer telescopes are in hot pur- suit of the first detection of the EoR signal. They hope to glimpse something within the next year or two—and the stakes could be enormous. Scientists say the 21-cm radia- tion could open up a floodgate of informa- tion about the astrophysics and cosmology of this unstudied part of the universe’s his- tory, perhaps comparable to the discoveries that have flowed from studying the cosmic 

microwave background left over from the big bang. But detecting the primordial ra- dio signal amid the cacophony of other ra- dio sources, earthbound and astronomical, is akin to hearing a whisper amid a crowd of cheering sports fans. “We’re learning all the lessons,” says Judd Bowman of Arizona State University, Tempe, chief scientist of one of the new instruments, the Murchison Widefield Array (MWA) in Australia. “We’re hopeful and eager.” 

in and around the peat bog at Exloo has 24 clusters, each containing more than 850 antennas, spanning a 4-kilometer- wide area; another 14 clusters are scattered around the Netherlands, plus another five in Germany and one each in France, Swe- den, and the United Kingdom. (More are under construction in Germany and Po- land.) Widely spaced stations give the in- terferometer finer resolution, enabling it to zoom in on smaller patches of sky. 

“To do what we do, you have to be hopelessly optimistic, but also brutally realistic.”

must identify them and strip them out.
No images or catalogs of sources exist for this poorly studied part of the spectrum; the teams must map it out themselves before they can discount it from their data. “After subtracting all the foregrounds, the signal- to-noise ratio is still one-tenth. You have to understand the noise [and] find out ways to
quantify it,” says ASTRON’s Brentjens.
Once that’s done, investigators will be rewarded not with an image of the neutral

hydrogen at the EoR, but rather a power spectrum: a statistical analysis of how the ra- dio signal varies across the sky. It will reveal whether the biggest variations occur over small distances or large ones—whether the bubbles of ionized gas were small, the handi- work of individual stars, or galaxy-sized cavi- ties. The teams should also be able to watch reionization unfold over time. The EoR may have lasted millions of years; 21-cm radia- tion from earlier in its history will have trav- eled farther and thus will be stretched out to a longer wavelength and a lower frequency than later radiation. So a signal detected at 140 MHz will be from an earlier time than one at 160 MHz.
As interferometers are sensitive to differ- ences, the middle of the EoR—when half the universe is neutral and half ionized—will produce the strongest signal. So the teams will be scanning the frequencies for a signal that has a peak and then drops off farther into the past (when more of the universe was neutral) and farther toward the present (when more of the universe was ionized). “These telescopes hope to learn two basic things: when the EoR happened and how long it lasted,” Bowman says. “That should be easy to read when they detect a signal.”
All three teams are optimistic that they will soon get their first glimpse of the EoR. “We’re getting pretty close to what theorists predict the signal level is, and we expect to do two or three times better with the data that is coming in right now,” De Bruyn says. He hopes LOFAR will get a “first-order result” by next year. The PAPER and MWA teams are similarly hopeful. But MWA’s Bowman adds that those projections are all based on theoretical models of the EoR sig- nal. “If there is no detection by 2020,” he ac- knowledges, “that will be a disappointment for the community.”

Because of the amount of signal process- ing required and the many different assump- tions that underlie the calculations, “there’ll be no eureka moment. It’ll be hard to con- vince ourselves [of the detection],” Brentjens says. Even harder will be convincing the rival teams. “I worry about this a lot,” says Aaron Parsons of UC Berkeley, who is head of PAPER. “I hope journal editors are very careful. It’s very important that papers are reviewed by people who are really knowl- edgeable. And we have to be very careful not to overstate claims.”
A confirmed and reliable signal from the time of reionization could amount to what some researchers are calling “a COBE mo- ment” for astrophysics. COBE was the NASA satellite that, in 1992, revealed the size of fluctuations in the microwave background and opened a floodgate of results in cos- mology. A glimpse of the EoR would give astrophysicists their own origins story and a starting point for studying the very first things to shine.
Knocking out an electron and ionizing hydrogen takes quite a lot of energy, so any potential ionizing source needs to produce a lot of photons at high energies—ultraviolet or higher. It’s expected that the first stars to

form in the universe were unlike any that ex- ist now because they were made of almost pure hydrogen, without any of the heavier elements that were forged inside stars as the universe aged. Pure hydrogen stars, known as population III stars, should grow to enor- mous size before their internal furnaces ignite—hundreds or even thousands of times as massive as our sun. Big stars burn bright, hot, and fast, making them a perfect source of ionizing radiation. But do they form in isolation, or does dark matter draw the hy- drogen into galaxies first? Or were bigger, more powerful sources such as quasars— hugely luminous galactic nuclei centered on supermassive black holes—the engine of reionization? Theorists speculating about the EoR have also invoked more exotic driv- ers, including decaying dark matter and cos- mic strings. “We’re shooting in the dark. We have no idea what they are,” Zaroubi says.
The existing arrays probably won’t be able to answer all of these questions. “To really understand how the first stars form and what early galaxies were like needs the next generation of instrument,” Parsons says.
The LOFAR team hopes to build up its ar- ray with more stations and faster computing. But the PAPER and MWA teams are joining forces to build a new, more powerful instru- ment called HERA, the Hydrogen Epoch of Reionization Array. HERA’s antennas will be static wire-mesh dishes pointing straight up. The joint team has won $2 million to build a test array of 37 dishes in the Karoo, using PAPER’s infrastructure. This alone will have

The Square Kilometre Array (left, in an artist’s conception) will use dishes and static antennas to pick up different radio frequencies. LOFAR (above) mingles low-frequency antennas (brown specks) with higher frequency ones (inside dark tiles).
up to three times the sensitivity of PAPER, Parsons says. Then the team will seek up to $20 million to build an array of 350 dishes by 2019. “We’ll turn the tables on theorists and really start to drive theory, really ad- vance our understanding,” he says.
Looming on the horizon is the next gen- eration: the Square Kilometre Array (SKA). This enormous international project will be built mostly in South Africa, starting in 2018, and will target everything from galaxy evo- lution to signals from extraterrestrial intelli- gence. But part of the array, to be sited at the Murchison Radio-astronomy Observatory, home of MWA, will collect low-frequency ra- diation with a quarter of a million antennas spread over 100 kilometers. With its huge collecting capacity, SKA will be able to move beyond statistical observations and produce images. “We’ll see the structures themselves directly. That’s a huge step,” Zaroubi says.

But first the rival teams need to catch that first glimpse of early light. They will have to overcome radio interference, computing challenges, and the deafening noise—and they must hope that theoretical models of the EoR signal are correct. Says Zaroubi: “To do what we do, you have to be hopelessly op- timistic, but also brutally realistic. You need both sides.” ■ 

Ebola fears hamper U.S. meetings

NEW ORLEANS, LOUISIANA | Fears of the Ebola virus are barring researchers from two scientific meetings in New Orleans. Several scientists—including representa- tives of the World Health Organization and the Centers for Disease Control and Prevention—had to cancel their trip to the annual meeting of the American Society
of Tropical Medicine and Hygiene this week after the state of Louisiana barred attendees who had treated Ebola patients or been in Guinea, Sierra Leone, or Liberia in the previous 3 weeks. The same rules will affect the annual convention of the American Public Health Association (APHA), held in New Orleans from 15 to 19 November, says APHA Executive

Director Georges Benjamin. Meanwhile, two infectious diseases meetings in Europe went ahead as planned this week because no Ebola travel restrictions applied in their host cities, Vienna and Stockholm. http:// scim.ag/Ebolamtgban, http://scim.ag/EbolaEur
Germans boost research funding
BERLIN | After months of deadlock, German politicians agreed on 30 October to a €25.3 billion ($31.6 billion) funding package for universities and research insti- tutes through 2020. The bulk of the new money, €19.3 billion, will go to universities. Nonuniversity research organizations like the DFG funding agency, the Max Planck Society, and the Leibniz Association will receive 3% annual budget increases from 2016 through 2020, down from recent 5%

yearly increases. Funding for overhead costs—a long-simmering issue—will rise from 20% to 22%. The country’s Excellence Initiative, a competition between universi- ties for extra funding, will also continue, though details won’t be worked out until after an evaluation of the program is fin- ished in early 2016.
Badges clarify co-authors’ roles

LONDON | A collection of science, publishing, and software groups is devel- oping a solution to the problem of how to identify the contributions of each of a paper’s authors: digital “badges”—such as “computation,” “investigation,” and “data visualization”—that detail what each author did for the work. Authors can link the badges to their profiles elsewhere on the Web. The collaboration, which includes BioMed Central, the Public Library of Science, Mozilla Science Lab, and ORCID (an effort to assign researchers digital identifiers), presented the project at the Mozilla Festival in London late last month. Early prototypes are scheduled to launch next year, according to Amye Kenall, journal development manager of open data initia- tives and journals at BioMed Central. http://scim.ag/_digitalbadges

 Science’s memory deepens

BOSTON | Today’s scientists are standing on the shoulders of giants, relying on the work of their predecessors—to whom they give a nod by citing their papers. But is the work of those predecessors becom-
ing obsolete, as scientists choose to cite more recent work? In a paper posted on arXiv, the team behind Google Scholar weighed in this week with a study of their own massive data set. The team analyzed papers published between 1990 and 2013 and compared the publication dates of citations listed in them. The results should give older scientists reason to cheer:
The fraction of citations that are at least 10 years older than the paper citing them has increased steadily, from 28% in 1990 to 36% in 2013, the team reports. http://scim.ag/papercites
Climate report sounds alarm
COPENHAGEN | Climate change is taking hold and will bring worrying impacts— but there is still time to limit the dam- age. That is the message delivered by
the Intergovernmental Panel on Climate Change’s (IPCC’s) Synthesis Report, released this week, which caps work on three massive studies issued by IPCC over the past year, comprising the group’s fifth assessment of climate science and mitigation since 1990. “The core message from the IPCC is the growing urgency of action,” said Bob Perciasepe, president of the Arlington, Virginia–based Center for Climate and Energy Solutions, in a state- ment. “The scientists have done their job. Now it’s up to governments to do theirs.”

New research chief touts dowsing

SYDNEY, AUSTRALIA | Larry Marshall, the next CEO of Australia’s leading research agency, the Commonwealth Scientific and Industrial Research Organisation (CSIRO), is in hot water after suggesting in a

recent radio interview with the Australian Broadcasting Corporation (ABC) that CSIRO investigate water divining, or dows- ing. Although it is “a little out there,” he tolCdapAtiBoCn ,heitr’esotfhtehisagency’s job to “push the enpvheoltoopaeb.”ovCeScIaRptOionscientists are keeping theheirehteoacdoms ed.own in the wake of a 5.45% (AU$111.4 million) budget cut that will see

up to 420 jobs eliminated by June 2015, along with the closure of eight research facilities. But experts outside the agency decried the interest in dowsing expressed by a Silicon Valley venture capitalist with a doctorate in physics. “I’m appalled,” says John Williams of the Wentworth Group

of Concerned Scientists and former chief of CSIRO Land and Water. http://scim.ag/CSIROdowsing