Random Samples

Science  25 Apr 2003:
Vol. 300, Issue 5619, pp. 577
  1. Architectural Bacteria

    Researchers have identified a strain of bacterium that may help preserve valuable stonework—such as Spain's 9th century Alhambra palace.

    Spain's limestone Puerta de las Granadas at the Alhambra and micrographs of stonework before and after treatment.


    Minerals such as limestone, dolostone, and marble are highly susceptible to weathering and pollution because of their porosity. Scientists in recent years have tried using carbonate-producing bacteria to coat delicate stonework with a tough layer of calcium carbonate. But they have hit a problem: The newly deposited mineral clogs stone pores, preventing the escape of moisture, which accelerates decay.

    Now, a team led by mineralogist Carlos Rodríguez-Navarro of the University of Granada reports promising results from tests of an abundant soil bacterium, Myxococcus xanthus, on samples of limestone widely used in Spanish historical buildings. The bacterium produces carbonate crystals that create a cement that binds to existing calcite grains, lining pores without plugging them. The newly deposited calcite matches the orientation of the existing crystals, and organic molecules that harden calcite make it even tougher than the original rock, the scientists report in the April issue of Applied and Environmental Microbiology.

    “The beauty of the treatment is that the repair material is chemically identical to the original limestone,” says Princeton University materials scientist George Scherer. But he warns that the calcite layer this bacterium deposits is shallow and thus still vulnerable. Tests now being carried out at the Alhambra, he says, should show whether these bacteria “can be persuaded to do their work deeper inside the stone.”

  2. DOE Pooh-Poohs Polygraph Proposals

    Waving off the warnings, the Department of Energy (DOE) intends to go ahead using lie detectors in employee and pre-employment screening.

    Last October, a panel of the National Academy of Sciences (NAS) concluded in a report, The Polygraph and Lie Detection, that lie detectors are not reliable enough to be used in personnel screening programs. Congress told DOE to “take [this report] into account” in its new polygraph regulations. But in the 14 April Federal Register, DOE—which is required to seek public comments on the regs—says it has decided that polygram exams are “a tool that appears in current circumstances well-suited” to security goals. It adds: “DOE does not believe that the issues that the NAS has raised about the polygraph's accuracy are sufficient to warrant a decision by DOE to abandon it as a screening tool.”

    Committee member Stephen Fienberg, a statistician at Carnegie Mellon University in Pittsburgh, says he's “disappointed” that the department “basically ignores our recommendations.” Fienberg says the panel believes reliance on polygraph results will actually endanger national security because officials may believe a test that “passes” an individual who is a security risk. The academy group recommended that polygraphs be limited to people with access to the most sensitive information.

    Critics of DOE polygraph policies are hoping that the issue will be aired in DOE oversight hearings to be conducted next month by Senator Pete Domenici (R-NM), chair of the Energy and Natural Resources Committee. A committee spokesperson says the agenda hasn't been set yet.

  3. Double Helix Coin


    Britain's Royal Mint has launched a £2 coin to celebrate the 50th anniversary of the discovery of the structure of DNA by James Watson and his British colleague Francis Crick. The coin may also help expand the vocabulary of the common person with the inscription “deoxyribonucleic acid” on the edge.

  4. Your Words Betray You

    That headline contains the tip-off: This was written by a woman. The clues? It's in the present tense, contains pronouns, and addresses the audience directly, says computer scientist Shlomo Argamon.

    Argamon and his co-workers at Bar-Ilahn University in Ramat Gan, Israel, have put together a computer program, called Winnow, that they claim can figure out an author's sex by his or her writing style.

    Winnow has taught itself, through extensive reading, to recognize linguistic patterns more commonly used by one or the other sex and has formed rules based on patterns of word usage and sentence structure. Women use words such as “for,” “with,” and “and” more often than men, signifying their more communal tendencies, says Argamon. Men are more quantitative and use more “determiners,” such as “an,” “a,” and “no.” The program's overall success rate, published last year in Literary and Linguistic Computing, was 80% in identifying the sex of authors of British works including fiction and writing in the arts, sciences, and social sciences. In a total of 264 fictional works, the authors of six were misidentified. A. S. Byatt was the only woman who wrote like a man; five male authors, including Michael Frayn, sound like women, according to Winnow.

    Even on 30 science texts, with their formal technical style, it scored 74%. “If I had asked you before you saw this, my bet would be that you would have thought there'd be no [gender] difference in nonfiction,” says Dan Roth, a computer scientist at the University of Illinois, Urbana-Champaign. The researchers will lay out further results in the August issue of Text.

  5. Playing Fair in Soccer and Science


    In 1996, Spanish physician Francisco Belda blew the whistle on soccer referees with a study showing that the human eye was too slow to judge offsides in many play situations. Now, a Madrid court has called a foul on the authors of a 1998 Lancet paper, ruling that it was a knock-off of Belda's work.

    Belda wrote up his research in the magazine of the Spanish Royal Football Federation in December 1996. When he later saw a “similar” paper in The Lancet titled “Oculomotor movements and football's Law 11,” Belda sued the authors, including Jaime Sanabria, an otoneurologist at Fundación Jiménez Díaz in Madrid.

    Belda's article attributes wrong offside decisions to the time it takes for the eye to shift from one visual target to another. (An offside occurs if a player is nearer to his opponents' goal line than to the ball, unless there are at least two opposition players between him and the goal line.) “Because the eye can't move quickly enough, the referee cannot simultaneously see the exact location of all the players around the ball as it is passed on,” he explains. Sanabria could not be reached for comment.

    In its ruling last December, the court asked the defendants to compensate Belda and ordered The Lancet to publish the verdict. Belda is asking the journal to print his original work along with the ruling. The Lancet says it hasn't yet decided how or whether it will comply.

  6. Notable

    Ever the party animal. The last few months have been “just a blur” to James Watson as the 75-year-old Nobel laureate celebrates the 50th anniversary of the discovery of the structure of DNA.

    Nearly banished from Washington, D.C., a decade ago by political conflicts with his boss, then National Institutes of Health (NIH) Director Bernardine Healy, Watson this month returned for a 2-day NIH symposium to honor him and co-Nobelists Francis Crick and Maurice Wilkins. Then came a black-tie shindig at the U.S. Library of Congress.

    Watson also prodded the U.K. organizers of that country's DNA events to include a dinner with dignitaries. “They were going to have just a 1-day celebration in Cambridge, and I thought they should do a little more,” he says.

  7. In The Courts


    High stakes. Things are still touch-and-go at the old Homestake gold mine in Lead, South Dakota, which scientists are fighting to appropriate for the world's deepest neutrino research laboratory. Last week physicists Alfred Mann (right in picture) and Kenneth Lande rushed to Lead to stop Barrick Gold Corp. from letting water into the 2300-meter-deep abandoned mine. Lande, a professor at the University of Pennsylvania, booked his flight as soon as he heard Barrick's announcement on 10 April that it was going to shut off the pumps that keep water out of the mine. More physicists would have shown up, he says, “but for the short notice.” As it turned out, the day before the scientists arrived for the protest, a state court had issued a temporary order to Barrick to keep Homestake's pumps running. Officials from Barrick and Lead city met this week to discuss the mine's future.

  8. Awards


    Goldman Prize. Pedro Arrojo-Agudo, a physicist and economics professor at the University of Zaragoza in Spain, is one of seven recipients of the 2003 Goldman Environmental Prize. Arrojo-Agudo, 52, wins the $125,000 award for leading a campaign against the Spanish government's plan to build 120 dams on the Ebro River. “Having a Ph.D. in fluid mechanics has been a plus while discussing water issues,” says Arrojo-Agudo.

  9. Sidelines

    Know-it-alls. It's not research but it is interdisciplinary. A physicist, a materials scientist, a biochemist, and a plant biologist have teamed up to compete in University Challenge, British television's legendary quiz show. Picked by the Royal Society, the group is one of 22 teams representing different professions that landed a spot on the program.


    In their first round, aired last week, University of Birmingham biochemist Bob Michell, Oxford materials scientist Martin Castell, Oxford plant biologist Harriet McWatters, and Cambridge physicist Mike Towler (pictured right to left) beat the Royal Institute of British Architects, acing questions on topics ranging from Shakespearean characters to advertising. But the team botched it on a question about T cells. Michell says he could have “answered in his sleep,” but he jumped in before the question was completed. That mistake could cost the team a place among the eight making it to the next round.