6,896 results
6,896 results for: Bears
- Health & Medicine
Do liver stem cells come from bone marrow?
Tests of liver tissue from people who've received liver or blood-marrow transplants show that stem cells in bone marrow can populate the liver as liver cells.
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Predators shape river world top-down
Hunting and no-hunting zones allow a rare test of the much-debated proposal that big carnivores shape their ecosystems from the top down.
- Animals
Flowers, not flirting, make sexes differ
Thanks to lucky circumstances, bird researchers find rare evidence that food, not sex appeal, makes some male and female hummingbirds look different.
- Materials Science
A new carbon nanotool springs to life
Physicists have pulled out the inside cylinders of multiwall carbon nanotubes, as if expanding a telescope, indicating how the devices may serve as tiny bearings and springs in future nanomachines.
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Promiscuity in guppies has its virtues
Mating with multiple partners benefits the female Trinidadian guppy and her offspring by reducing gestation time and producing youngsters more adept at forming protective schools and at evading capture.
- Earth
Early Shift: North Sea plankton and fish move out of sync
As ocean temperatures in the North Sea have warmed in recent decades, the life cycles of some species low in the food chain have accelerated significantly, sometimes wreaking ecological havoc.
- Animals
Policing egg laying in insect colonies
Kinship by itself can't explain the vigilante justice of some ant, bee, and wasp workers.
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Babies’ sound path to language skills
A test of early speech perception shows promise as a way to identify 6-month-olds headed for language difficulties as toddlers.
- Animals
Mom bears more sons when she gets extra bouquets
When researchers spiff up a male starling's courtship by delivering some extra bouquets to his mate on his behalf, the couple tends to produce more sons than usual.
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Cancer Flip-Flop: Gene acts in both proliferation and control of growth
Scientists have identified what might be a new class of cancer-controlling genes that alternates between halting and promoting cancer.
- Physics
Marrying matter and light
Physicists have created circuit components that, in a manner analogous to atoms, meld with light, opening new ways to study fundamental light-matter interactions.
- Astronomy
Big Smash: Galaxy clusters in collision
Astronomers have unveiled the most detailed image ever taken of the collision of two clusters of galaxies.
