The Christmas Day airplane bombing attempt has renewed the debate over full body scanners at airports. The Transportation Security Administration in recent years has tried out a series of “whole-body imagers” to look for threats that typical metal detectors can’t find. These systems are the only way that smuggled explosives, like the one officials say was brought on the Christmas flight, can be reliably found [Wired.com].
Privacy advocates are calling the full body scanners a “digital strip search” (take a look at this TSA image of a full body scan and you’ll get the idea). But some security advocates say that either patting down every passenger or taking full body scans are the only options to ensure certain dangerous items are kept off airplanes.
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Are CT scans putting thousands of people in unnecessary jeopardy for cancers and death? That was the suggestion by two new studies out this week, leaving radiologists scrambling to explain the true level of danger to worried patients.
A CT scan, also known as computed tomography, gives doctors a view inside the body, often eliminating the need for exploratory surgery. But CT scans involve a much higher radiation dose than conventional X-rays. A chest CT scan exposes the patient to more than 100 times the radiation dose of a typical chest X-ray [Reuters]. However, a study out of the University of California, San Francisco says, we might not have as good a handle on CT radiation as we thought. The researchers found that radiation differed greatly between machines, and some emitted 13 times more than others.
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The elites of ancient Egypt had money, power, divine status in the case of the pharaohs, and also heart disease. In a study in today’s issue of The Journal of the American Medical Association, a team of researchers reports performing x-ray scans of 20 Egyptian mummies and finding them rife with cardiovascular disease like clogged arteries, one of the commonest ailments in modern American society.
On a visit to the Museum of Egyptian Antiquities in Cairo, one of the researchers had been intrigued by a nameplate on the remains of Pharaoh Merenptah, who died in 1,203BC. The plate said the pharaoh died at the age of 60 and suffered diseased arteries, arthritis and tooth decay [The Guardian]. So the scientists obtained permission to scan that mummy and others in the museum collection.
The common people of ancient Egypt weren’t mummified; only elites like royal families, their nursemaids, and priests got such a treatment. The elites ate salted fish, bread, and cheese like everyone else, but they also dined on rich foods such as cow, sheep, and goat meat, as well as honey and cakes with butter, says Abdel Nureldin, a professor of Egyptology at Cairo University, who worked on the investigation. At the same time, virtually no one in ancient times was sedentary, and that may have helped counteract their fatty diets [ScienceNOW Daily News].
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Peeling a roll of ordinary sticky tape can generate 100 milliwatt pulses of X-rays, enough to capture a human finger on X-ray film, according to a new study by UCLA scientists. They claim to have found the cheapest way to produce X-rays of that scale. “At some point we were a little bit scared,” says Juan Escobar, a member of the research team. But he and his co-workers soon realized that the X-rays were only emitted when the kit was used in a vacuum [Nature News].
Their kit consisted of a vacuum-enclosed machine, reminiscent of a video casette player, that peeled a roll of Photo Safe 3M Scotch tape at a rate of 3 cm per second. Rapid pulses of X-rays, each about a billionth of a second long, emerged from very close to where the tape was coming off the roll. That’s where electrons jumped from the roll to the sticky underside of the tape that was being pulled away, a journey of about two-thousandths of an inch, Escobar said. When those electrons struck the sticky side they slowed down, and that slowing made them emit X-rays [AP]. This type of energy release is known as triboluminescence — the same principle behind the fun trick of crunching on Wint-O-Green Live Savers to produce blue sparks.
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In a neat marriage of science and art, researchers used x-rays from a particle accelerator to reveal an early portrait of a woman by Vincent Van Gogh, which the impoverished artist later painted over with a meadow scene. The hidden image bears a striking resemblance to a series of somber portraits the artist produced in the Dutch town of Nuenen, where he composed “The Potato Eaters,” completed in 1885 and regarded as his first major work [Los Angeles Times].
An earlier analysis using conventional x-rays had shown the rough shape of a head hidden beneath the surface of a painting called “Patch of Grass,” but provided no details. To get a clearer image, the researchers used high-intensity x-rays from a particle accelerator in Hamburg, Germany to compile a two-dimensional map of the metallic atoms on the painting beneath “Patch of Grass.”… Knowing that mercury atoms were part of a red pigment and the antimony atoms were part of a yellow pigment, they were able to chart those colors in the underlying image. “We visualized — in great detail — the nose, the eyes, according to the chemical composition.” [researcher Joris] Dik said. Scanning a roughly 7-inch square of the larger portrait took two full days [AP].
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