Uncategorized
- Health & Medicine
A Toast to Healthy Hearts: Wine compounds benefit blood vessels
Researchers have identified a class of compounds in red wine that might be responsible for much of the beverage's cardiovascular benefit.
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19764
This article says that a planet so close to a red dwarf would be forced to “rotate in sync” with the star. Is this the same situation that causes the moon to rotate in sync with Earth? Ken BollersHudson, Colo. Yes. First, the larger body (the red dwarf) pulls the smaller body (the planet) slightly […]
- Planetary Science
Howdy, Neighbors: Long-term study finds a batch of red dwarfs
Astronomers have found 20 previously unknown star systems that lie within 33 light-years of Earth.
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19763
If membership in a species is characterized by the inability to breed with members of another species, how can there be “animal species known to have arisen from crossbreeding with other species? Jeffry D. MuellerEldersburg, Md. Exceptions happen. Also, biologists argue about what defines a species. —S. Milius I suggest that the new species be […]
- Animals
New Butterfly: High-alpine species from low-life parents
Little bluish butterflies high in the Sierra Nevada could be one of the few animal species to have arisen from crossbreeding of two other species.
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19762
Your article made a common mistake in characterizing the mechanism of steroid-hormone receptors. These receptors are not “proteins on the cell surface” but rather, and uniquely, positioned intracellularly. Steroid hormones pass directly from the bloodstream to the cytoplasm, where they induce changes in the receptor proteins, enable movement into the nucleus, and activate specific genes. […]
- Health & Medicine
Cancer Link: Gene regulates progesterone effect on breast cells
The BRCA1 protein regulates the effect of pro-growth progesterone, which could explain why having a mutated BRCA1 gene predisposes a woman to breast cancer.
- Earth
Leaden swan song
Large numbers of trumpeter swans are succumbing to lead poisoning as a result of ingesting old shotgun pellets in areas where use of lead shot has been banned for more than a decade.
- Earth
No-stick chemicals can mimic estrogen
Some of the perfluorinated compounds used to impart nonstick properties to fabrics and cookware can not only activate a receptor for sex hormones but also inappropriately feminize fish.
- Earth
Sharks, dolphins store pollutants
Florida's top aquatic predators are rapidly accumulating high concentrations of brominated flame retardants and other persistent toxic chemicals.
- Earth
Could Prozac muscle out mussels?
Antidepressant drugs may be depressing wild-mussel populations.
- Health & Medicine
Test identifies people at cardiac risk
Measurement of an electrical abnormality in the heart aids doctors in determining who is most at risk for cardiac arrest.
