Uncategorized
- Earth
Just a Tad Is Too Much: Less is worse for tadpoles exposed to chemicals
The herbicide atrazine is more likely to kill developing amphibians when it is highly diluted than when it's much more concentrated in aquatic environments.
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The counterintuitive finding that atrazine is more likely to kill tadpoles when it is highly diluted reminds me of a similar phenomenon in the alternative health care practice of homeopathy. Tracy SellersRowlett, Texas
- Physics
Grainy Geyser: Tall squirts reveal sand’s liquid ways
Dropping a steel ball into fine, loosely packed sand produces towering jets of grains.
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Clearing Up Blurry Vision: Scientists gaze toward causes of myopia
Scientists are beginning to unravel the genetic mechanism that causes nearsightedness.
- Archaeology
Mexican murals store magnetic data
Tiny magnetic particles in the pigments of some Mexican murals recorded the direction of Earth's magnetic field when the paint dried.
- Health & Medicine
Protective enzyme has a downside: Asthma
The abnormal production of a parasite-fighting enzyme contributes to asthma.
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Watching the biological clock
Biologists now have a way to predict when a woman will start menopause.
- Archaeology
Rat DNA points to Pacific migrations
An analysis of mitochondrial DNA from Pacific rats supports a theory that ancestors of today's Polynesians migrated from Southeast Asia to a string of South Pacific islands in at least two separate dispersals.
- Earth
Warmer climate, decreased rice yield
Agricultural data gathered over a dozen years at a Philippines rice paddy suggest that climate changes brought about by global warming could significantly diminish rice yields.
- Materials Science
DNA coordinates assembly of glassy nanoscale structures
Chemists use DNA as a scaffold to construct miniature rings and rods out of silica.
- Health & Medicine
Caloric threats from sugarfree drinks?
Regularly downing sweet drinks or sugar substitutes may foster overeating by reprogramming an individual's ability to judge a snack's caloric impact.
- Astronomy
Controlling the speed of solar eruptions
The billion-ton blobs of magnetized gas that the sun sporadically hurls into space can't reach Earth in less than half a day.
