Monday, April 22, 2013

A Bear’s Brain Surgery, Babies’ Consciousness and More

from nytimes




Matt Hunt
In Laos, an Asiatic black bear with hydrocephalus — water on the brain — became the first bear to have a brain operation.
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You’re up in space — weightless — with a wet washcloth. What will happen when you wring it out?
NASA
Chris Hadfield wrung out a wet washcloth while aboard the International Space Station for an experiment designed by two 10th graders in Nova Scotia.
Even on Friday, when everyone was riveted to the manhunt in Boston, anonline video from the International Space Station about that question was a suspenseful and intriguing diversion. What happened to the water in microgravity turned out to be “much more interesting than what happens here on earth,” as The Los Angeles Times put it.
Before we give you the answer, here’s the context: Canada’s equivalent of NASA held a contest for schoolchildren, asking them to design a simple experiment that the Canadian astronaut aboard the space station could perform using particular household items, office supplies and the like. The list of nearly 50 items included dental floss, nylon running shorts, ketchup, mustard and a magnifying glass.
Two 10th-grade girls from Nova Scotia, together with their science teacher, came up with the wet washcloth idea, chosen from nearly 100 entries. So last Tuesday, the commander of the space station, Chris Hadfield, a veteran spacewalker, recorded a video in which, with a microphone bobbing near his mouth, he unfurled a white washcloth, squirted drinking water onto it, then twisted the saturated cloth. In what looked like a magic trick, the water began surrounding the washcloth in a thick layer, then migrated outward.
“It’s becoming a tube of water,” Commander Hadfield said, staring intently at the cloth over his signature mustache. “It wrings out of the cloth onto my hands.”
Because of the surface tension of the water, he explained, the fluid ran along the exterior of the fabric and onto him, where it stuck, “almost like you had Jell-O on your hand.” He wiped his wet hands and left the washcloth, still twisted, dangling in place. “Great experiment, worked perfectly,” he said. The 10th graders had predicted the outcome spot on. “Their hypothesis that the water would not drip in microgravity but rather remain on the washcloth was proven correct,” as the Canadian Space Agency put it in a news release. “In the absence of gravity to pull the water down, it took a shake or a quick squeeze from Commander Hadfield for the washcloth to release the water.” Or, as one person commented on the video on YouTube, “Everything is cooler in space.”
Developments
Veterinary Medicine
Ursine Neurosurgery
In Laos, an Asiatic black bear with hydrocephalus — water on the brain, which causes fierce headaches — underwent laparoscopic surgery, becoming the first bear ever to have a brain operation, National Geographic reported. “Rescued as a cub, Champa stood out from the start,” the magazine said. “She had a protruding forehead and had trouble socializing with the other bears at the sanctuary. Over time, her growth slowed, her behavior became more erratic, and her vision faded.” Euthanizing Champa was not considered an option in the largely Buddhist country, so a British veterinary surgeon,Romain Pizzi, who describes his specialty as “minimally invasive ‘keyhole’ surgery of wildlife,” operated on her, just as he has done on seals, reindeer and jaguars. Six weeks post-op, Champa looked perkier, her caretakers said; she had gained weight and grown chummier with other bears.
Health
Warding Off Breast Cancer
It has long been a thorny topic: Should healthy women take tamoxifen and raloxifene, powerful drugs that can reduce their risk of breast cancer but can also cause life-threatening strokes and blood clots? Some resolution arrived last week, when the United States Preventive Services Task Force — a gold standard among medical experts —recommended that doctors offer to prescribe the drugs for women with higher than average risk of breast cancer and low risks of blood clots and strokes. The drugs work by blocking the effects of estrogen in breast tissue, where it can stimulate the growth of some tumors. “These medicines may have benefits for women who are at increased risk of breast cancer and at low risk for harms from the medicines,” the task force said in a fact sheet, but “women who are not at increased risk for breast cancer should not use tamoxifen or raloxifene to reduce their risk for breast cancer.”
Infant Development
What Do Babies Know?
Five-month-old infants can’t tell you what they are seeing and thinking (though their mothers can, of course). But if you attach electrode caps to their heads — which is harmless, though it looks disturbing — you can get a glimpse of their brain activity. AFrench neuroscientist did this, plopping infants in their parents’ laps and measuring the neural patterns generated when the babies viewed a face flashed on a screen. In results that seem oddly reassuring, the babies showed the same brain reactions that adults do — a “two-phase pattern that would indicate consciousness,” as the Web site LiveScience put it — but it took them longer to get there. “In 5-month-olds, it took 1.3 seconds for the second flurry of brain activity to show up,” LiveScience noted. “In adults, the timing is closer to three-tenths of a second.” The small study, which was published in Science, adds weight to the argument that very young infants are conscious of their surroundings, meaning that their reactions are not just reflexive.
Geology
Earth Shakings
Two bits of seismic activity news came up last week — totally separate, both startling. One was that the horrific fertilizer plant explosion in West, Tex., which caused at least 14 deaths and left a wide swath of devastation, was so powerful that the United States Geological Survey registered it as a 2.1-magnitude earthquake. And the seismic impact ofHurricane Sandy last October may have been the same or larger: Keith D. Koper, a geophysicist at the University of Utah, and a colleague reported that waves pounding the seafloor generated “microseisms” that were picked up around the country. “There is no magnitude scale for the microseisms generated by Sandy, but Koper says they range from roughly 2 to 3 on a quake magnitude scale,” ScienceDaily, a news Web site, reported. “The conversion is difficult because earthquakes pack a quick punch, while storms unleash their energy for many hours.”

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