Letters to the Editor
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19873
This article ignored important research by David Tilman and Jason Hill of the University of Minnesota. They found that planting a crop of 18 different native prairie plants grown in highly degraded and infertile soil with little fertilizer or chemicals yielded substantially more bioenergy than a single species in fertile soil. In fact, their crops […]
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19872
The research described in this article draws sound conclusions. However, the context suggests the tests were done at constant speeds. I submit there is yet another cause. It has been my observation that washboarding occurs initially and primarily at areas where there is acceleration, such as coming out of curves and starting up inclines. Don […]
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19871
Margit L. Bleecker appears to have discovered that those who score highly on reading tests also score highly on tests of memory, attention, and concentration. I don’t find that highly surprising. Ivan MannHoover, Ala.
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19870
This article reviews efforts to explain why certain biological molecules tend to be all right-handed (e.g., sugars) or left-handed (e.g., amino acids). An explanation might lie in the evolution of enzymes involved in their synthesis. For example, the fact that some organisms produce predominantly d-alanine could be explained by random mutations for the opposite enzyme […]
- Humans
Letters from the August 18, 2007, issue of Science News
Exhaustive analysis I would debate the “1,000 watts or more” value attributed to typical adults during strenuous exercise (“Powering the Revolution: Tiny gadgets pick up energy for free,” SN: 6/2/07, p. 344). Hiking up steep slopes, I rarely exceed 250 W myself, and typical hikers are going much slower. The 1,000-watt figure can only apply […]
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19869
Recent reports of plastics such as dioxin and now bisphenol A make me wonder if there are any Alzheimer’s-linked aluminum ions or atoms or whatever floating around in our soda cans. Those glass bottles from yesteryear are starting to look very wholesome. Linda ZimmermanTorrance, Calif.
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19868
Osteocalcin may well be the answer to the startling, nearly three-times-stronger glucose control observed in downhill walkers, compared with people walking uphill (SN: 12/11/04, p. 380). The eccentric exertion of downhill walking could be stimulating more osteocalcin release from osteoblasts. Members of our burgeoning prediabetic civilization may be inspired to generate their own osteocalcin by […]
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19867
Based on the Environmental Protection Agency’s Web resources on radon, I find that the decreases in radon levels in the summer are unlikely to be caused by a lack of air currents from less temperature differential in houses. The EPA states that an open window can be effective in reducing radon levels. And when are […]
- Humans
Letters from the August 11, 2007, issue of Science News
Sum kids While testing was done on 5- or 6-year-old children (“Take a Number: Kids show math insights without instruction,” SN: 6/2/07, p. 341), it would be interesting to see if this intuitive skill persists after these students are exposed to standard mathematical instruction in the higher grades. I suspect that the answer will be […]
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19866
Conservation by America is not going to decrease global warming. We need to imitate known global-cooling events, such as the Krakatoa volcano explosion, which spread sunlight-reflecting dust into the stratosphere in 1883. A hydrogen bomb exploded inside a ship full of white clay could be a first step. Daniel ShanefieldHonolulu, Hawaii Recent research suggests that […]
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19865
It’s certainly true that “[T]he most important factor that correlates with success in college is what is done in high school math.” But is the headline true? How about, “More years of team basketball makes kids grow taller”? That’s a strong correlation, too. John M. FlaniganKaneohe, Hawaii While some self-selection certainly happens—the kids who take […]
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19864
A simpler explanation for orangutans walking upright like humans is that this feature evolved in a common ancestor that did not include African apes. In other words, orangutans, not chimpanzees, are our closest living relatives. This would make sense of all the similarities in sexuality, reproduction, physiology, anatomy, and behavior that are unique to humans […]
