Random Samples

Science  08 Apr 2005:
Vol. 308, Issue 5719, pp. 195
  1. Lifesaving Pitchers

    CREDIT: ROB REED

    Ancient disinfection. People in rural India have long believed that storing water in brass pitchers can ward off illness. A new study backs that idea, finding that traditional brass pitchers release tiny amounts of copper that kill harmful bacteria.

    Rob Reed of Northumbria University in Newcastle, U.K., verified the pitchers' powers with collaborators at Panjab University in Chandigarh, India. The microbiologists filled brass pitchers with sterile water inoculated with Escherichia coli and with contaminated river-water samples collected in India. Fecal bacteria counts in all samples dropped from as high as 1,000,000 bacteria per milliliter to zero after 2 days. Bacteria levels stayed high in water stored in earthenware or plastic pitchers. The brass pitchers contained traces of dissolved copper, enough to kill bacteria, Reed reported this week at the Society for General Microbiology annual meeting in Edinburgh, U.K. The study, he notes, “supports an ancient, anecdotal kind of belief.”

  2. Fastest DNA Computer

    A biomolecular computer that uses little more than DNA and enzymes could perform a billion operations simultaneously, say scientists led by Ehud Keinan of the Technion-Israel Institute of Technology in Haifa.

    Three years ago, a joint team from Technion and the Weizmann Institute of Science in Rehovot, Israel, published a paper in Nature on a DNA-based computer. But the machine was limited to only 765 simultaneous programs and, unlike this new system, it required human supervision.

    The new biomolecular computer is described in the March 2005 issue of the Journal of the American Chemical Society. Computations are carried out by processing the input (double-stranded DNA molecules) with the help of enzymes that chop and reassemble the DNA in a series of steps. The output is in the form of a slightly altered DNA molecule.

    The system's complexity “is certainly novel and [has] never been achieved before,” says Natasha Jonoska, a mathematician at the University of South Florida, Tampa.

  3. Fish Farm Hazards

    CREDIT: ALAN PIKE

    Killer sea lice. Parasitic sea lice that jump from fish farms to wild salmon may be a much greater problem than suspected, according to a new report likely to inflame an ongoing battle over aquaculture risks.

    The idea that fish farms act as reservoirs of infection for passing wild fish is controversial in the United States and Canada. To test the theory, researchers at the University of Victoria (UVic), Canada, looked for lice on more than 5000 juvenile wild pink and chum salmon along a migration route close to a fish farm in British Columbia. The scientists plugged their lice counts, along with environmental parameters, into a mathematical model.

    The results, in the 29 March issue of the Proceedings of the Royal Society, indicate that the juveniles started out generally lice-free but became heavily infected after passing the farm. And the lice held on for 30 kilometers, making the “migrating school a moving cloud of infection” that can be passed to other species such as stickleback and herring, says John Volpe, a marine ecologist at UVic.

    “This is an excellent paper,” says Ransom Myers, a fisheries biologist at Dalhousie University in Halifax, Nova Scotia. But Scott McKinley, a physio-logist at the University of British Columbia in Vancouver, calls the study “flawed” because it lacks “lice data from the farm itself.”

  4. Gulf's Dead Zone Worse in Recent Decades

    CREDIT: LISA OSTERMAN/USGS

    Coring spot. A seasonal dead zone in the northern Gulf of Mexico developed occasionally in the 1800s, according to a new study. But its data suggest that the zone has become more intense in the last few decades as farmers cranked up fertilizer use.

    Coastal bottom waters off Louisiana now become depleted of oxygen almost every summer when nutrient-rich Mississippi River water causes populations of tiny marine plants called phytoplankton to explode. When they die, their decomposition sucks oxygen from the bottom waters. Fish and other animals then flee the area.

    Most scientists believe that chemical fertilizer is a major cause of the seasonal dead zone, but the fertilizer industry and a few scientists are skeptical (Science, 9 February 2001, p. 968). To probe past conditions, a team led by micropaleontologist Lisa Osterman of the U.S. Geological Survey in Reston, Virginia, took sediment cores from the consistently hypoxic zone. They dated cross sections and counted three species of tiny animals called foraminifers that tolerate low-oxygen waters.

    As far back as 1823, the hardy foraminifers thrived during Mississippi River flood years, suggesting that nutrients in floodwaters can trigger natural hypoxia. But the foraminifers were much more abundant after 1960, when Mississippi River Basin farmers began laying on commercial fertilizer. That has apparently driven low-oxygen episodes “very far off scale,” says Osterman, whose study appears in the April issue of Geology.

    Although intrigued by the study, marine biologist Robert Diaz of the Virginia Institute of Marine Sciences in Gloucester Point cautions that the sediment-dating technique used can be off by a few years.

  5. Taking Stock at NIH

    CREDITS: DUKE UNIVERSITY MEDICAL CENTER; NIH JULIA MALAKIE/AP

    The new conflict-of-interest rules at the National Institutes of Health (NIH) are driving one institute director to leave and delaying the arrival of another. James Battey (left), director of the National Institute on Deafness and Other Communication Disorders, has told NIH officials that he plans to quit before the provisions concerning investments take effect this fall. And lung disease researcher David Schwartz of Duke University in Durham, North Carolina, who was to take the helm next week at the National Institute of Environmental Health Sciences (NIEHS), is having second thoughts about the position.

    Battey says he is unable to comply with the ban on senior employees owning biomedical stocks because he manages a family trust fund. “I can't abandon that responsibility,” he says. The same ban is deterring Schwartz, who sent a letter to NIH Director Elias Zerhouni expressing his concerns about its possible effect on recruitment and retention of scientists. In an e-mail to Science, Schwartz said he still plans to come to NIEHS and is “confident that my concerns can be addressed.”

    Battey was promptly removed from his post as chair of the NIH Stem Cell Task Force last month after he told NIH officials about his plans to leave. His next job could take him back to his native California: He says he's “one of many candidates” for a top position at the California Institute for Regenerative Medicine, which will distribute the state's $3 billion Proposition 71 funding for stem cells and cloning. Allen Spiegel, director of the National Institute of Diabetes and Digestive and Kidney Diseases, and Story Landis, director of the National Institute of Neurological Disorders and Stroke, have been named co-chairs of the Stem Cell Task Force.

  6. In The News

    CREDIT: TERRY J. ADAMS/NATIONAL PARK SERVICE

    Time to bloom. Early April is the time to enjoy Washington, D.C.'s premier spring event: the blossoming of thousands of cherry trees. It's also a time to doff your hat to horticulturist Robert DeFeo of the National Park Service, whose job is to predict when the flowers will be in full bloom.

    For much of the winter, DeFeo checks the buds daily to gauge their readiness. One month before the Cherry Blossom Festival, he announces his best guess of when peak intensity will occur. Although the festival's dates have been chosen months in advance, DeFeo's predictions help countless tourists and local residents plan their sightseeing. This year's prediction, 4 to 9 April, is his 15th, 13 of which have been right on the mark despite the erratic March weather. “I am just amazed [at his accuracy],” says Margaret Pooler of the National Arboretum in Washington, D.C.

  7. They Said It

    “They definitely hold a special place in my heart. I always considered them to be my second set of grandparents.”

    CREDIT: THE ALAN MASON CHESNEY MEDICAL ARCHIVES OF THE JOHNS HOPKINS MEDICAL INSTITUTIONS

    —Elizabeth Carr, the first test tube baby of the United States, on Georgeanna Jones and her husband Howard Jones, who pioneered in vitro fertilization in the country and established the program leading to Carr's birth. The 24-year-old Carr made the comment in an interview to The Baltimore Sun after Georgeanna Jones died in Norfolk, Virginia, on 26 March. She was 92.

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