Uncategorized
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19501
It should be noted that DDT was a poor example to use as an enantiomeric insecticide in this article, since that chemical doesn’t have an asymmetric carbon and therefore can’t exist in “mirror forms.” Gordon W. GribbleHanover, N.H. DDT is a mixture of three forms of the chemical, one of which has enantiomers—not due to […]
- Earth
Reflections on Insecticides: Mirror forms of agrochemicals set risk
The toxicity of an insecticide or how long it persists in the environment depends on which mirror-image form of the chemical is present.
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19500
In light of the findings reported in this article, it seems obvious that there’s a need for anthropologists to revisit the records of local “legends” as they study human development in any area. Doesn’t it seem absurd that anyone studying human history would discard actual reports from humans about their own history? Elizabeth BolltPotsdam, N.Y.
- Anthropology
Temples of Boom: Ancient Hawaiians took fast road to statehood
A boom in temple construction on two Hawaiian islands around 400 years ago marked the surprisingly rapid formation of an early political state.
- Health & Medicine
Beat Generation: Genetically modified stem cells repair heart
Tissue engineers have for the first time used genetically modified human stem cells to repair damaged hearts in guinea pigs.
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19499
Your article has a graphic that appears to show an area that lifted by up to 5 meters and a vaguely equal area that was depressed by up to 2 m. This suggests an average increase in the distance of mass from the center of Earth. Yet a researcher claims that Earth’s rotation time has […]
- Earth
Tsunami Disaster: Scientists model the big quake and its consequences
Scientists are modeling the immediate and long-term effects of the magnitude 9.0 earthquake that struck west of Indonesia the morning of Dec. 26, 2004, and triggered tsunamis that killed tens of thousands of people.
- Astronomy
Ring robber
Images taken by the Cassini spacecraft provide graphic evidence of Saturn's moon Prometheus stealing particles from the planet's narrow F ring.
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19498
I wonder if the upsurge in alien, invasive species in real estate boom areas is, at least in part, because of careless gardening. Many people introduce non-native plants into their landscape without regard to the potential for domination of these pretty plants over native species. Carol SenskeGreen Lane, Pa.
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Plants: Importance of being economic
The pulse of the real estate market in a given area turns out to be a powerful indicator of how many exotic plant species have invaded the neighborhood.
- Astronomy
A dwarf with a disk
The Hubble Space Telescope has examined in unprecedented detail a ring of debris around a star that could be the nearest and youngest known home for planets outside the solar system.
- Earth
Ocean-sensor project reaches milestone
Oceanographers seeking to deploy an armada of 3,000 robotic probes to take the pulse of Earth's oceans have passed the halfway mark and hope to have the full array of sensors in place by 2007.
