-- The latest twist on fighting fire with fire pits "good" bacteria against bad. It's called probiotics, and it may help prevent food poisoning from foul fowl. Researchers at Britain's Institute of Food Research have identified a microbial strain that totally destroys one harmful bacterium in the guts of chickens. The researchers hope to find more beneficial bacteria and eventually reduce the need for antibiotics in chicken feed. Antibiotic-laced animal feed is widely believed to be a factor in the rise of drug-resistant "superbugs" that increasingly cause fatal infections in people. Downhill ski racing isn't for the fainthearted. Contestants regularly top 150 mph. The current record is a blazing 250.7 kilometers per hour, or almost 180 mph.
Racer Martin Lachaud aims to break that record. He's hoping to hit 255 kph at the Pro Mondial competition now under way at Les Arcs ski resort in France. His sponsor, Paris-based Skis Rossignol, has developed a "space ski" with technology borrowed from the European Space Agency.
Rocketing over the snow at such speeds, even tiny surface variations cause the skis to vibrate, and the shudders disturb the smooth flow of water, produced by friction, that lubricates the underside of skis. So Rossignol adapted a system used to keep space instruments rock-steady. Embedded in the skis are piezo actuators from France's Cedrat Technologies -- in essence, smart shock absorbers that detect vibration and generate opposing forces to cancel it out.
Corrections and Clarifications
"Schussing without shuddering" (Developments to Watch, Apr. 26) confused downhill ski racing with speed skiing. In the latter sport, the speed record is 250.7 kilometers per hour, or 156 mph.
One worry about global warming is that the increased concentration of greenhouse gases will upset earth's balance and bring changes in ocean circulation. In an extreme case, scientists say, the flow of warm currents up the Atlantic Ocean to Europe might be shut down. That would cause temperatures to plunge in Western Europe. Such a shift may be unlikely, but anxious researchers have been keeping a keen watch for any variations in ocean flow, using satellites and instruments moored out in the sea.
Now, they are starting to spot some potentially worrisome changes. In the Apr. 15 online issue of Science, a NASA-University of Washington team reports that the counterclockwise circulation of surface water in the North Atlantic has become markedly weaker since the early 1990s. "These observations of rapid climate changes over one decade may merit some concern," the authors write. But they also caution that it's not yet clear if the shift in circulation is the result of man-made global warming or part of a natural cycle. Jet planes powered by coal? It's possible, according to researchers at Pennsylvania State University. But the coal has to be liquefied and mixed with some dregs of oil refining, so don't look for any coal trucks roaming airport tarmacs.
Developed for the latest hot-shot jet engines, particularly those in the new F-35 Joint Strike Fighter, the coal-based fuel remains stable at temperatures up to 900F. That's important, says Harold Schobert, director of Penn State's Energy Institute, because the new engines generate so much heat that air cooling isn't sufficient. Fighter jets can't afford to lug coolant, so the fuel is used to cool the engine before it gets burned.
The production process for coal-based fuel has been engineered to combine easily with normal petroleum refining, "and we could tweak the process," Schobert says, to yield a fuel suitable for ordinary jets. That could put a dent in oil imports, since jet fuel accounts for roughly 10% of total oil refinery output in the U.S.