Uncategorized
- Materials Science
Heal thyself—again and again
A new self-healing material can repeatedly repair damage at the same spot.
- Earth
Tree rings tell tale of megadroughts
Tree rings in ancient timber show that the Colorado Plateau experienced a 60-year drought in the 12th century.
- Animals
Moths mimic ‘Don’t eat me’ sounds
Moths that make clicking noises at predatory bats are mimicking a defensive signal made by other moths that click and also taste bad.
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19845
In this article, the study is reported as the “first confirmed acoustic example of classic defensive mimicry.” Not so. In 1986, Matthew P. Rowe and colleagues published in Ethology an elegant study demonstrating that the burrowing owl’s hiss is acoustic defensive mimicry of the rattlesnake’s rattle. William K. HayesLoma Linda UniversityLoma Linda, Calif.
- Archaeology
Ancient beads found in northern Africa
Perforated shells found in a Moroccan cave indicate that northern Africans made symbolic body ornaments 82,000 years ago, long before Europeans did.
- Health & Medicine
Diabetes drug might hike heart risk
People who take rosiglitazone, a popular diabetes drug marketed as Avandia, may face an increased risk of heart attack.
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19844
Your article reports 86 heart attacks among 15,560 rosiglitazone (Avandia) users, versus 72 others in a control group of 12,283. A study coauthor then says that “after statistical adjustment, that yields a 43 percent higher risk of heart attacks among rosiglitazone users.” Simple arithmetic would seem to indicate it was the control group that had […]
- Health & Medicine
Stents Stumble
After a meteoric rise, stents coated with drugs to prevent renarrowing of clogged arteries have begun to fall from favor among cardiologists.
- Earth
Storm Center
Scientists aboard planes that flew into the cores of Katrina and other hurricanes in 2005 collected unprecedented data on the structure and development of the massive storms.
- Humans
Letters from the June 23, 2007, issue of Science News
Bad start In “Violent Justice: Adult system fails young offenders” (SN: 4/21/07, p. 243), an association is found between young offenders being tried as adults and increased criminal offenses later. The implication is made that one thing causes the other. Perhaps a better interpretation of the data would be that, because not every young offender […]
- Humans
From the June 12, 1937, issue
Waterflow downstream of a dam, the shape of an asteroid, and connections between wallpaper patterns and crystal structures.
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The Green Guide
National Geographic’s Green Guide offers objective information and practical advice to consumers on how to lead a greener life. Go to: http://www.thegreenguide.com
