holiday snack under attack

Posted on December 30, 2003 by agnieszka

What would the holidays be like without those almost-impossible-to-crack dark-brown Brazil nuts on the table? We might find out if the Brazil nut industry doesn’t change its ways, says a study in the Dec. 19 Science. Brazil nut trees are among the oldest and largest in the Amazon forest — they can live 500 years or more and grow 160 feet tall — and their grapefruit-sized fruits hold 10 to 25 nuts each, which are collected when the fruit drops to the ground. The nuts are the only internationally traded crop collected entirely from natural forests. In the Brazilian Amazon alone, 45,000 tons of nuts are collected annually, with sales of more than 33 million US dollars, according to the study. Now Carlos Peres of the University of East Anglia and an international group of scientists warn that “current Brazil nut harvesting practices at many Amazonian forest sites are not sustainable in the long term.” After examining Brazil nut tree groves in 23 sites in the Bolivian, Peruvian, and Brazilian Amazon, the researchers found that new trees are not adequately replacing aging trees where nuts are intensively collected. Young trees “were most common in unharvested and lightly harvested stands” and “virtually absent where seeds had been persistently collected,” they wrote. Due to the longevity of the trees, there will be no shortage of nuts in the near future, but the researchers recommend steps to avoid the collapse of the industry, including planting more seeds and limiting and rotating harvests so the stands may have a chance to regenerate.

This news brief appeared in the Random Data column of the Boston Globe’s Health/Science section on 12/30/2003.
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silver is the safest choice

Posted on December 23, 2003 by agnieszka

Silver was the most popular car color in the United States, Europe, and Asia last year, according to the most recent DuPont Global Color Popularity report, and its popularity doesn’t appear to be waning. Silver is a safe choice, in more ways than you’d think. Researchers from the University of Auckland in New Zealand report in the Christmas issue of The British Medical Journal that silver vehicles are less likely to be in a car crash involving serious injuries than other-colored autos. Looking at more than 1,000 drivers involved in crashes between 1998 and 1999, Sue Furness and her colleagues found an approximately 50 percent reduction in the risk of serious injury in silver cars compared with white cars, even taking into account factors that could affect the results, such as seat-belt use, vehicle age, and road conditions. Brown cars carried the highest risk of serious injury, and black and green cars also had higher risk. Yellow, gray, red, and blue cars carried risks similar to white. The researchers had no explanation for their finding, but it’s speculated that silver, being a light color and highly reflective, may make cars more visible on the roadway. So if you are looking for a new vehicle, perhaps silver is golden.

This news brief appeared in the Random Data column of the Boston Globe’s Health/Science section on 12/23/2003.
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man’s new best friend

Posted on December 23, 2003 by agnieszka

When you think of the heroes of the animal world, rats don’t usually come to mind. Oh, sure, they’ve been used in countless experiments that have greatly enhanced scientific knowledge, but they’re not working right by our side like dogs, for example, leading the blind and sniffing out explosives. Well, perhaps we don’t have guide rats just yet, but a Belgian research organization in Tanzania has successfully used giant pouched rats (Cricetomys gambianus) to sniff out land mines, and the same rat researchers are now training them to detect tuberculosis in humans. New Scientist reports that preliminary tests suggest the rats could test as many as 150 saliva samples in 30 minutes, compared to a human using a microscope, who can only test 20 samples in a day. The researchers use reward-based training to sensitize the giant rats (which can grow to the size of housecats) to the smell of the TB bacteria in human saliva samples. The rats are trained to stop in front of a sample with the target smell, and then are rewarded with bananas and peanuts. So far, using 10,000 samples, the rats have a 77 percent accuracy rate in identifying infected samples, compared to a 95 percent accuracy rate with a microscope. Bart Weetjens, the director of the rat program, hopes that by using three or four rats on each sample, the accuracy rate will be increased.

This news brief appeared in the Random Data column of the Boston Globe’s Health/Science section on 12/23/2003.
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stop light

Posted on December 23, 2003 by agnieszka

Scientists may not be able to turn back time, but physicists at Harvard University have stopped light in its tracks. Mikhail Lukin and colleagues have brought light, which normally travels at a phenomenal 186,000 miles per second, to a complete standstill for a fraction of second, they report in the Dec. 11 issue of Nature. Researchers have previously slowed light to a crawl, and light has been halted before, but never without its energy being lost. Lukin’s group is the first to stop a pulse of light with all its energy — its photons — intact. The researchers fired a pulse of red laser light into a cylinder filled with hot rubidium gas and used two control beams whose interaction simulates a surface of tiny mirrors. The light particles are essentially reflected back and forth between the beams so that the light pulse can’t move forward and is “frozen” in place. The researchers held the pulse still for 10 microseconds, and then, by releasing the control beams, allowed it to continue on its merry way.

This news brief appeared in the Random Data column of the Boston Globe’s Health/Science section on 12/23/2003.
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look at my chimp genes

Posted on December 16, 2003 by agnieszka

From bacteria to mice to men, add the chimpanzee, our closest relative, to the growing number of creatures having their genomes — their genetic blueprints — sequenced and decoded. Eric Lander of the Broad Institute, a joint venture between the Massachusetts Institute of Technology and Harvard University, is one of the lead researches. This first draft of the chimpanzee genome has been placed on the Internet for all and sundry to gawk and gaze upon, completely free of charge, at www.ncbi.nih.gov/Genbank. To help biomedical researchers they have also aligned the chimpanzee sequence with the human sequence, so areas of interest can be compared. It should help provide valuable information on human disease, human evolution and population genetics. But just in case you decide to look up the sequence and find you don’t understand what it means, don’t despair. An international team of scientists is even now pondering the exact same thing and plans on publishing their analysis in the next few months. And geneticists from Cornell University and Celera Diagnostics have already made a stab at pointing out some differences: Looking at the chimp draft in progress, they report in the Dec. 12 Science that genes involved in smell and hearing are significantly different between the two species. Perhaps, one day very soon, we’ll finally know exactly what, genetically speaking, makes up humans and not chimpanzee.

This news brief appeared in the Random Data column of the Boston Globe’s Health/Science section on 12/16/2003.
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nuclear-powered search for life

Posted on December 16, 2003 by agnieszka

Not so long ago, NASA’s now-defunct Galileo mission found hints that some of Jupiter’s moons held oceans of liquid water beneath their frozen crusts, sparking the question, if they harbor water, do they harbor life? To help answer that question, NASA is proposing to launch a new unmanned spacecraft to Jupiter that will orbit, one after another, three of its planet-sized moons (Callisto, Ganymede, and Europa) that are suspected of having subsurface oceans. The Jupiter Icy Moons Orbiter, or JIMO, will contain a uranium-fueled, nuclear-fission reactor that will power the huge craft and its array of scientific equipment. JIMO will be outfitted with high-resolution cameras and radar to help penetrate deep into the icy crusts and allow extensive, detailed mapping of the surfaces of the moons. According to NASA, the onboard nuclear reactor would generate an unprecedented 100 times more electrical power than any current interplanetary probe, allowing JIMO to send back more data than previous unmanned missions. Some activists oppose the idea, fearing an explosion during launch. If funding is approved, the craft is scheduled for takeoff sometime after 2011.

This news brief appeared in the Random Data column of the Boston Globe’s Health/Science section on 12/16/2003.
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flashes that forecast?

Posted on December 16, 2003 by agnieszka

Researchers from the University of Arizona have found that rain and lightning are intimately linked. Before you snicker at the obviousness of the findings, E. Philip Krider of the University’s Institute of Atmospheric Physics, collaborating in two independent experiments, stated that counting lightning flashes may be used to help estimate the volume of precipitation. “We found that lightning is a good tool for predicting rain volume, and it doesn’t matter if it’s a big storm or a small storm,” Krider stated in a press release. But the type of storm cloud does seem to matter. The researchers found that predictions worked best with clouds that extend vertically high up into the atmosphere. Studying storms in Florida, Krider, working with Bruce Gungle, consistently found that warm-season thunderstorms produced about 4 million gallons of rain for each lightning strike. In a separate study, Krider and Nicole Kempf looked at meteorological records of cloud-to-ground lightning and surface rainfall over the Greater Upper Mississippi River Basin during the Great Flood of 1993. They also found a strong relationship between daily rain amounts and the corresponding counts of lightning. “The rain volume does go slightly up and down, because rain sampling isn’t perfect, but it does fit a statistically testable, strong relationship,” Krider stated. “In these large ‘mesoscale’ convective systems, you can see where the lightning is, count the flashes, and immediately have an estimate of surface rainfall.”

This news brief appeared in the Random Data column of the Boston Globe’s Health/Science section on 12/16/2003.
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runner’s high?

Posted on December 9, 2003 by agnieszka

Most of us know a compulsive runner or gym rat who completely freaks out if they have to miss a workout, but it’s been debated whether exercise addiction is a real or imaginary phenomenon. Now a study from the University of Wisconsin-Madison in the Dec. 1 issue of Behavioral Neuroscience suggests that it may indeed be a physical condition. Researchers showed that animals deprived of exercise revealed brain activity normally associated with drug withdrawal. Zoologist Stephen Gammie and his colleagues studied a special type of mouse, bred to run longer distances than the typical lab mouse. Both the “high-running” mice and the lab mice were allowed to run on a wheel for as long as they liked for six days, with the high-running mice running as much as three times farther in the same amount of time than the lab mice. On the seventh day, the researchers denied access to the wheel to half of the mice in each group, allowing the others to run as before. Then the researchers measured the brain activity in each group. All the mice denied the wheel showed high levels of activity in 16 out of 25 brain regions, but, stated Justin Rhodes, one of the paper’s authors, “in the high-running mice, certain brain regions displayed extremely high levels of activity, more than normal. These were the same brain regions that become activated when you prevent rats from getting their daily fix of cocaine, morphine, alcohol, or nicotine.” Whether these findings apply to humans still remains to be seen, but true “gym mice” appear to exist after all.

This news brief appeared in the Random Data column of the Boston Globe’s Health/Science section on 12/09/2003.
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winter sports threatened by warming

Posted on December 9, 2003 by agnieszka

As if rising sea levels aren’t scary enough, here’s another reason to fear global warming: It could force your favorite ski resort to close. A report issued by the United Nations Environment Program last week said that as global temperatures increase, and the snowline retreats to higher altitudes, many existing low-altitude mountain resorts throughout the world will lack reliable snow cover, be cut off from their ski runs, and risk financial ruin. In one worst-case scenario, none of Australia’s ski resorts would be viable by 2070. The report used temperature forecasts produced by the Intergovernmental Panel on Climate Change, a group of some 2,000 scientists, which estimated that world temperatures will rise anywhere from 2.5 to 10.4 degrees Fahrenheit by 2100 unless greenhouse gas emissions are radically reduced. UNEP executive director Klaus Toepfer said that global warming — in the form of extreme weather such as floods and droughts — will have the most devastating impact on the world’s poorest nations, but “this study on winter sports shows that it is not just the developing world that will suffer. Even rich nations are facing potentially massive upheavals with significant economic, social and cultural implications.”

This news brief appeared in the Random Data column of the Boston Globe’s Health/Science section on 12/09/2003.
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fast food becoming a bear necessity

Posted on December 9, 2003 by agnieszka

It seems that black bears are prone to the diet and exercise problems of our modern-day, fast-food existence. According to a recent study published in the Journal of Zoology, black bears living in and around urban areas are up to a third less active and weigh up to 30 percent more than bears living in more wild areas. Biologists from the Wildlife Conservation Society have observed that the bears aren’t actively foraging for berries or carrion as they normally would in the wilderness, but instead are dumpster-diving behind the mall or at fast-food restaurants for their meals. “Black bears in urban areas are putting on weight and doing less-strenuous activities,” stated Jon Beckmann, the lead author of the study. “They’re hitting the local dumpster for dinner, then calling it a day.” The researchers also have found that the bears have become more nocturnal than their country cousins, presumably to avoid interacting with humans, and the time they spend in their winter dens also has declined, thanks to a year-round supply of food.

This news brief appeared in the Random Data column of the Boston Globe’s Health/Science section on 12/09/2003.
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