Random Samples

Science  07 Mar 2003:
Vol. 299, Issue 5612, pp. 1511

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  1. Fighting Brain Shrinkage

    Aging brains, just like aging bodies, are more robust if treated to regular cardiovascular workouts. Human brains start gradually losing tissue after age 30, and this shrinkage is matched by declines in cognitive performance. But it's been known for years that fit older adults do better on mental tests. Now a brain-imaging study has supplied anatomical evidence that exercise can beef up the brain too.

    In the study, researchers used a magnetic resonance imaging (MRI) device to determine the 3D structure and density of the brains of 55 adults, aged 56 to 79. Their physical fitness was assessed by 1-mile walking and treadmill stress tests. Those who swam, walked, jogged, or cycled at least 20 minutes a day, several days a week, showed less decline in brain density in both gray (cell bodies) and white (axons) matter, report neuroscientists Arthur Kramer, Stan Colcombe, and colleagues at the University of Illinois, Urbana-Champaign, in the February Journal of Gerontology: Medical Sciences. Kramer says the effect becomes more pronounced with age.

    MRIs: areas of cortex that shrink with age (left); areas of cortex affected by exercise (right).


    Although this experiment looked only at the results of aerobic exercise, the scientists say they have evidence that strength training or other exercise may produce similar effects. The new results are consistent with studies using animals, says Carl Cotman, director of the Institute of Brain Aging and Dementia at the University of California, Irvine. Work with rodents has shown that modest, repeated activity can improve learning and memory. Kramer believes that it is not just increased blood circulation to the brain that provides the benefits. Animal research, he says, shows that exercise produces more neurotrophins, small proteins that are thought to dispose of harmful free radicals and to encourage neuronal and synaptic growth.

  2. Monkey Wrench

    The disappearance last month of a small, gray monkey from a primate research facility on the campus of the University of California, Davis, has inflamed community fears over biodefense research and could torpedo the university's efforts to land a $200 million biosafety lab sponsored by the National Institutes of Health (NIH).

    The monkey, a 2-kg female rhesus macaque, darted out of her cage during a routine cleaning on 13 February. An employee reported seeing the monkey disappear behind a cage, followed by a gurgling sound from an open 10-cm drainpipe. Subsequent searches, which included the use of a fiber-optic camera to search the drainpipes, failed to turn up the vanished primate. Police believe that she died somewhere in the maze of sewage pipes under the research center.


    Residents anxious about the prospect of hosting some of world's most dangerous microbes, including Ebola and Nipah (a pig virus lethal to humans), have inundated city hall with worried calls and e-mails, says Davis city council member Sue Greenwald. The general sentiment, she says, is “They can't keep a monkey from disappearing, and they think they'll keep microbes from disappearing.”

    In response to the outcry, the city council has taken a stance against the proposed biosafety level-4 facility, one of several that NIH hopes to fund. University spokesperson Marjorie Dickinson says that the university has no plans to withdraw its proposal but is exploring other options.

  3. Nano-Bloom

    Materials scientists have used temperature control to grow themselves a bunch of beautiful indium nitride flowers. Each flower is a single crystal just 0.002 to 0.01 mm across with six tiny petals. The flowers bloom when a mixed vapor of indium chloride and ammonia reacts and the product condenses on a slice of hot (700 K) silicon.


    The materials horticulturalists, led by Naoyuki Takahashi of Shizuoka University in Japan, reckon that the 3D control they have demonstrated with their florid crystals could blossom into a new nanotechnology field. They report their technique in a forthcoming issue of Chemical Communications.

  4. Patent Factories

    California's nine research universities led U.S. academic patenters in 2002 for the ninth straight year, and New York's system made the biggest gain, jumping nine spots over last year's ranking (in parentheses).

  5. Stacking Up the Evidence

    Mathematician Thomas Hales of the University of Pittsburgh has launched a 20-year electronic effort to prove that he has solved Kepler's conjecture.

    The conjecture, put forth in 1611 by astronomer Johannes Kepler, holds that the densest way to pack spheres is to place them in a pyramid—the same way grocers stack oranges. In August 1998, Hales, then at the University of Michigan, made front-page news by announcing that he and his graduate student Sam Ferguson had achieved a computer-aided proof. The 250-page manuscript was submitted to the Annals of Mathematics.

    The journal assigned a team of a dozen mathematicians to review the proof, a job that took more than 4 years. Their conclusion: They're 99% certain that it's correct. The Annals has decided finally to publish the study, accompanied by a cautionary note.

    Hales with cannonballs.


    But Hales wants to go for 100%. To that end, he hopes to enlist a global squad of programmers and mathematicians in what he has dubbed the “Flyspeck Project.” He's running a seminar on Flyspeck and has a Web site (www.math.pitt.edu/~thales/flyspeck) on which he spells out criteria, including mathematical training and knowledge of programming languages, for joining the fun. He anticipates a core group of about 10. “I am finding tremendous support for the project locally,” he says, noting that there's a rich history of “automated proof verification” at Pittsburgh going back to the 1950s.

  6. Jobs

    Unchained. Columbia University is looking for postdocs who can turn undergraduates into science lovers. The school is adding science to its 84-year-old core curriculum of required courses (Science, 18 October 2002, p. 531), beginning this fall with 350 entering freshmen. The university needs three postdocs to lead nondisciplinary discussion groups that will supplement the lectures and offer real-life examples of the scientist as explorer.

    “It's a cultural change” for all concerned, admits biology professor Darcy Kelley, whose recruitment efforts are part of her work under a Howard Hughes Medical Institute program to integrate research and teaching. “Most faculty want to chain their postdocs to the lab bench.” The 3 hours a week postdocs will spend in the classroom won't jeopardize their research, she says, and it will give postdocs a chance “to interact with students and explain how scientists think.”

    The astronomer slot is filled, but there's still room for a physicist and a biologist. The salary is $40,000.

  7. Awards

    Winning women. Some senior women scientists have bitter memories of the sexist obstacles they faced in carving out a career. But not Johanna Levelt Sengers, one of five winners last week of the L'Oreal-UNESCO prize for women in science. It's the first time the 5-year-old awards have gone to physical scientists.


    Sengers, a physicist turned engineer, has spent 40 years researching supercritical fluids at the U.S. National Institute of Standards and Technology (NIST). In a 1999 speech at the American Physical Society, the Dutch-born Sengers described how she was hired while pregnant with her first child—and how NIST (then the National Bureau of Standards) allowed her to work 6-hour days for 9 years. (She had three more children.) Awards and honors followed, including membership in the National Academy of Sciences and the National Academy of Engineering. Said Sengers, “NIST is a good place for women to be.”

    The other winners are physicist Karimat El-Sayed of Ain Shams University in Cairo; electron microscopist Fang-Hua Li of the Chinese Academy of Sciences in Beijing; physicist Ayse Erzan of Istanbul Technical University; and physicist Mariana Weissmann of the Argentine National Research Council in Buenos Aires. Each receives $100,000.

  8. Data Point

    In the rotation. The National Science Foundation (NSF) hopes to get around a ceiling on federal employees by increasing its use of scientists on loan from universities. Its latest budget request calls for a 21% boost in so-called rotators, who typically come for 2 or 3 years to manage a program, from 140 to 170 people.

    Their presence is intended to help NSF cope with a rising workload triggered by a growing budget. Last year, NSF processed more than 35,000 proposals, a 10% boost over 2001 and a 25% rise since 1999. NSF's workforce of 1290 has grown by only 4% during that time.

  9. In The Courts

    Engineer sentenced. Anatoly Babkin, a 73-year-old engineering professor at Moscow's Bauman Technical University, has joined the lengthening list of at least a half-dozen Russian scientists tripped up in recent years by international collaborations. On 19 February, Babkin received an 8-year suspended sentence after being found guilty of espionage for working with U.S. businessman Edmond Pope, who in 2000 became the first American in 40 years to be convicted of espionage in Russia. Babkin was also stripped of his academic credentials and barred from university work for 3 years.


    “The Federal Security Branch [successor to the KGB] pursues cases like this to warn impoverished Russian researchers not to be tempted to share information which they consider sensitive,” says Anatoly Diakov, a security analyst at the Russian Ministry of Education. “Unfortunately, despite years of protests, the policy continues.” Babkin will appeal the verdict.