More Stories from the January 25, 2003 issue
- Earth
Snow alga may be sizable carbon sink
A common microorganism that adds a reddish tinge to some patches of snow may be a significant consumer of planet-warming carbon dioxide.
- Earth
Contraceptive ring could pose risks after its disposal
Discarded vaginal contraceptive rings could interfere with fishes' reproduction by releasing estrogen into streams.
- Physics
Clocking gravity
The first attempt to measure the speed of gravity finds it roughly equal to that of light, as expected, though not everyone agrees that the method used can actually measure gravity's speed.
- Astronomy
Sundancing
Astronomers have solved the mystery of why supergranules—enormous cells of turbulent, charged gas on the sun's surface—appear to move across the sun faster than the sun rotates.
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Goodnight moon, hello Mom
A national study finds that about 13 percent of U.S. infants now routinely sleep in a bed with their mothers or other adults, intensifying interest in alleged health benefits and risks of bed sharing for babies.
- Earth
Estrogens classified as carcinogens
The sex hormones known as steroidal estrogens, which are used in hormone-replacement therapies and birth control pills, have joined a government list of known human carcinogens.
- Paleontology
Wings Aplenty: Dinosaur species had feathered hind limbs
A team of Chinese paleontologists has discovered fossils of a small, feathered dinosaur that they say had four wings.
- Astronomy
In the Beginning: Dark matter builds galaxies, feeds quasars
Cosmologists say they have found compelling evidence that massive galaxies were already in place when the universe was less than a billion years old.
- Tech
Fiber Helper: Minuscule controllers may open data floodgates
A device that fits on the end of optical fibers may make possible the next big boost in Internet speed without new underground cables.
- Health & Medicine
Too Much of a Good Thing: Excess vitamin A may hike bone-fracture rate
Dietary studies suggest that people who consume large amounts of vitamin A in foods or multivitamins are more likely to suffer hip fractures than are people who ingest modest amounts.
- Animals
One-Two Poison: Scorpion starts with a cheap shot
A South African scorpion economizes as it stings, injecting a simple mix first, followed by a venom that's more complicated to produce.
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Smells Like Emotion: Brain splits duties to sniff out feelings
A study suggests that a brain structure called the amygdala assesses the emotional intensity of both pleasant and unpleasant sensations, thus challenging prior evidence that it primarily coordinates fear responses.
- Chemistry
Unnatural Biochemistry: Bacteria make and use an alien amino acid
Researchers have constructed an organism that synthesizes and incorporates an extra amino acid into its proteins.
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From Bone to Brain: Transplanted male bone marrow makes nerve cells in women and girls
Transplanted bone marrow can form new nerve cells in the brains of people.
- Astronomy
Planet Formation on the Fast Track
New computer simulations suggest that planets as massive as Jupiter may have formed in only a few hundred years rather than several million years, as the leading theory of planet formation requires.
- Health & Medicine
Getting the Bugs Out of Blood
Researchers are developing methods for inactivating all sorts of pathogens that could be found in blood, including West Nile virus, an emerging infection recently brought to the United States from Africa.
