Vol. 170 No. #29
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More Stories from the December 23, 2006 issue

  1. Tech

    Shape shifter shifts twice

    Certain plastics known as shape-memory polymers switch to predetermined shapes when triggered by heat or light. Now, researchers have developed more-versatile versions of such polymers. When heated, each of the new triple-shape polymers switches to a second shape. Then, at a higher temperature, the plastic changes to a third form. “For some applications, [these] more-complex […]

  2. Planetary Science

    Signs of recent water on Mars

    Pictures showing fresh deposits of bright material on two Martian gullies provide the most compelling evidence yet that water flowed on parts of the Red Planet during the last few years.

  3. Restricting calories keeps immune system young

    Drastic limits on calorie consumption starting early in a monkey’s life seemed to delay aging of the animal’s immune systems in new research. Numerous studies have found that calorie restriction can extend the life span of organisms such as yeast, worms, fruit flies, and mice. However, scientists don’t know how caloric restriction lengthens life. Janko […]

  4. Paleontology

    Mammals started flying when birds did

    The first gliding mammal winged through forests at least 70 million years earlier than scientists had previously presumed, a new fossil shows. The specimen dates from about 150 million years ago, during the time when birds were developing flight. ANCIENT GLIDER. Volaticotherium antiquus was gliding through ancient forests 150 million years ago. The creature weighed […]

  5. Humans

    European chemical legislation adopted

    A groundbreaking chemical law, passed by the European Parliament on Dec. 13, is set to fundamentally change the evaluation and production of chemicals used throughout the European Union. The Registration, Evaluation and Authorization of Chemicals (REACH) law, which will go into effect in June 2007, takes a different approach than current U.S. policy does. It […]

  6. Decoding a protein to fend off sepsis

    From Orlando, Fla., at a meeting of the American Society of Hematology Sepsis is a lethal blood disorder that typically arises from bacterial infections. It’s marked by organ damage caused by inflammation and blood vessel leakage. A synthetic version of activated protein C (ACP) is the sole drug approved to specifically attack sepsis, but it […]

  7. Health & Medicine

    Drug takes a shot at leukemia cells

    From Orlando, Fla., at a meeting of the American Society of Hematology A drug that targets solid tumors such as those of lung cancer might also fight blood cancers, a lab study shows. Erlotinib (Tarceva) attacks cells by blocking a receptor protein that’s abundant on the surface of some cancer cells (SN: 8/27/05, p. 139: […]

  8. Health & Medicine

    Experimental clot inhibitors match conventional drugs

    From Orlando, Fla., at a meeting of the American Society of Hematology Two new drugs—one in pill form and another requiring only a single weekly injection—prevent dangerous blood clots in leg veins just as well as do standard treatments that require daily shots, two European research teams report. In one study, scientists in Sweden focused […]

  9. Health & Medicine

    Transplant reaction reversed in patients

    From Orlando, Fla., at a meeting of the American Society of Hematology Patients with leukemia get a fighting chance when they receive a transplant of bone marrow cells from a healthy donor. Unfortunately, immune cells from these new arrivals can run amok in the recipient, creating a life-threatening complication called graft-versus-host disease (GVHD). Last year, […]

  10. Animals

    No-Dad Dragons: Komodos reproduce without males

    Two female Komodo dragons in zoos have startled their keepers by laying viable eggs without males, possibly as a last resort at a time when mates are in increasingly short supply.

  11. Aging Lessons: Training gives elderly practical assistance

    Sessions aimed at improving memory, reasoning, or visual concentration in healthy elderly people yield notable cognitive returns, even 5 years later, a long-term study suggests. The training largely protected the participants from age-related declines in the ability to perform everyday tasks such as preparing meals, doing housework, and managing money. A handful of booster sessions […]

  12. Not so Silent: Mutation alters protein but not its components

    A single swap in the letters of a gene's sequence could modify the protein it encodes, even if it doesn't change which amino acids make up the molecule.

  13. Planetary Science

    Craft reveals Martian site of ancient water

    The distribution of materials in this composite image of the Nili Fossae region of Mars tells scientists that water resided there no more recently than nearly 4 billion years ago. Green indicates clay minerals that formed in a wet environment. Red depicts the mineral olivine, which formed about 3.8 billion years ago, according to the […]

  14. Health & Medicine

    AIDS Avoidance: More studies find that circumcision deters HIV

    Two large trials in Africa find that male circumcision limits HIV infection, which could prompt governments on that continent to promote or subsidize the operation.

  15. Planetary Science

    The Big Picture: Cassini spies Titan’s tall mountains

    A spacecraft has discovered the largest mountains known on Titan, Saturn's smog-shrouded moon.

  16. Earth

    Irony on High: Global warming cools, thins upper atmosphere

    Increasing concentrations of carbon dioxide and other greenhouse gases in the air, which cause temperatures at Earth’s surface to warm, will turn the upper layers of the atmosphere cooler and thinner in coming decades, new research suggests. This counterintuitive phenomenon, first predicted in the late 1980s and recently inferred from satellite data, will probably lead […]

  17. Tech

    Ahead of the Curve: Novel morphing wing may reduce aircraft’s fuel use

    A prototype aircraft wing has demonstrated in its first flight tests that its morphing might save fuel.

  18. Humans

    Science News of the Year 2006

    A review of important scientific achievements reported in Science News during the year 2006.

  19. Computing

    What a Flake

    New ways to simulate ice-crystal growth yield patterns remarkably similar to the beautiful and intricate shapes of snowflakes and may shed light on how those real-life shapes come about.

  20. Math

    Crafty Geometry

    By mastering traditional handicrafts such as knitting and crocheting, mathematicians are better able to understand complex surfaces.

  21. Earth

    Rocking the House

    A recent test that simulated the effect of a magnitude-6.7 earthquake on a full-size, wood-frame townhouse may help engineers and analysts design more earthquake-resistant homes. With sound and video.

  22. Humans

    Letters from the December 23 & 30, 2006, issue of Science News

    Playing dead is a lively topic I am amazed that “Why Play Dead?” (SN: 10/28/06, p. 280) concluded that “Scientists have a long way to go to explain why” prey animals play dead. As a veterinarian, I have learned that there are separate centers in the brain dealing with predatory behavior and with hunger. The […]