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There's a sunglass lens for every activity: amber for skiing, dark gray for the beach, and yellow for driving at dusk. Now scientists are developing "smart" lenses that can display different colors at the flick of a switch.
Of course, glasses that go from transparent when indoors to tinted in bright light are nothing new. The prototype lenses made by a team from University of Washington can show blue, and soon red or green. A knob in the frame activates a mini battery that sends out a charge. An "electrochromic" polymer in the lens responds by adjusting the level of darkness and color in a second or two. Unlike earlier attempts at technicolor eyewear, which needed a steady flow of current, these lenses need only a pulse to change, so they use less energy. Unveiled at March's American Chemical Society meeting, the color shifting shades could hit the market in a couple of years. Colorful coral reefs are imperiled by climate change. Already, damage from sewage, fishing, and pollution has led to widespread declines in these complex ecosystems. Rising CO2 levels are the latest threat. As the gas accumulates in the air, more CO2 dissolves into seawater. There, it turns into an acid that slowly dissolves corals' outer skeletons. There is hope for some species, though. Israeli researchers tested hard-shelled coral in water 10 times as acidic as today's oceans—what ocean water may be like in 150 years. Publishing in Science, they report that the corals lost their skeletons yet did not die. Instead, they survived as soft-bodied polyps. The findings suggest that while reefs remain at risk, some coral species may avoid extinction, says Maoz Fine, a marine zoologist at Bar-Ilan University. One tantalizing observation about multiple sclerosis is that it goes into remission during pregnancy. The degenerative disease occurs when the immune system attacks nerve cells. And it's known that pregnancy hormones such as estriol turn down the mother's immune system to protect the fetus from rejection. So could estriol—a form of estrogen—also be a treatment for the disease in women?
Rhonda Voskuhl, director of the MS program at the University of California at Los Angeles, decided to try. In a small study four years ago she showed that the hormone—available as a pill—brought a dramatic reduction in the brain inflammation that is harmful in MS.
Estriol "may not only help bring the immune system under control," says Patricia A. O'Looney, vice-president for biomedical research at the National Multiple Sclerosis Society, "but it may also stimulate cells to make more myelin," a protective sheath that helps nerves carry signals but that breaks down as MS progresses.
That's why Voskuhl is embarking on a larger, two-year study with previously untreated MS patients to see if estriol's benefits translate into improved health. Even if the hormone proves no better than current treatments, it has two big advantages: It's cheap, and it can be taken orally instead of being injected. Although men aren't part of her estriol study, Voskuhl is researching whether testosterone might have a similar effect in male MS patients. — From towering mastiffs to tiny Chihuahuas, dogs have more variety in size than any other mammals. Now, by studying the DNA of 143 dog breeds, scientists hope to learn more about how people grow. Researchers from the National Human Genome Research Institute have identified a gene variant that gives small-breed dogs their pipsqueak stature. Since humans have the gene, too, the discovery could yield clues to how height is genetically programmed in humans.
— Today's silicon-based solar cells are so mirror-like that lots of the sun's energy is lost when photons are reflected away. But scientists at Georgia Institute of Technology have cut these losses. Using carbon nanotubes, the team grew ultra-tiny "towers" across the surface of the cell. The structures not only increase the cell's surface area, which boosts the amount of sunlight it can absorb, but also help it to catch more rays by trapping photons that carom into the gaps between the structures. The findings are a step toward making a new kind of solar cell that will be smaller, lighter, and cheaper than today's silicon cells.