SSS听力文本汇总.docx

1、SSS听力文本汇总Do Cardiovascular Implants Get Enough Testing?A paper in the Journal of the American Medical Association points out that many implantable cardiovascular devices appear to get FDA premarket approval without what the authors consider to be sufficient published test results. Cynthia Graber rep

2、orts We like to think that medical equipment implanted in our bodies undergoes rigorous testing before its put inside a person. Thats not always the case, at least for cardiovascular devices. Thats according to an article in the Journal of the American Medical Association.Researchers evaluated the F

3、DA premarket approval process for 78 high-risk devices, such as pacemakers, stents and implanted defibrillators. They had assumed that these types of devices should and would be subject to random double-blinded studies with controls over an appropriate time-frame to investigate safety and efficacy.

4、But for 51 of the devices65 percentapproval was based on a single study. Only 27 percent of studies were randomized, and only 14 percent were blinded. Only half of the devices were compared with controls. The authors recognize the tension between sufficient testing and the need to get new drugs and

5、devices to the public. But, they say, “The bar for evidence of benefit should be higher for devices because they are implanted and cannot simply be discontinued, as drugs can. In addition, although devices can be lifesaving, they also have great potential for risk and adverse events.”Cynthia GraberC

6、omputers Cant Show You the MonetA study in the journal Computers & Graphics finds that computer programs for identifying works of art fall far short of even nonexpert human judges, because of our ability to psychologically evaluate scenes. Molly Webster reports No surprise: machines and humans have

7、differing opinions about art. Researchers from the Max Planck Institute and the University of Girona had computers and non-art expert humans place each of 275 paintings into one of 11 artistic periods, for example, Baroque or Surreal. And, unlike in chess, people far outshone their silicon competito

8、rs. Thats according to a study in the journal Computers & Graphics.Computer algorithms judged the art by obvious and quantifiable parameters, such as the way the paint was laid on the canvas, or the color composition. But humans classified art based on complex psychological evaluation. We ask questi

9、ons such as, who is in the image? And, what emotions are being portrayed in the scene? This kind of analysis is crucial for correctly identifying artbecause even non-expert people were right two thirds of the time, far better than their computer competitors. And that makes sense: ultimately, art is

10、about our emotional reaction to a Starry Night or a Girl With A Pearl Earring. But to a computer its all just brushstrokes.Molly WebsterAnimal Mimics: More Than Just CamouflageA study in the journal Science finds that animals that use mimicry-for example, an insect closely resembling a twig-are inde

11、ed seen and ignored by predators, not merely missed by them as a camouflaged insect would be. Karen Hopkin reports January 5, 2010Sometimes it pays to look like a pile of poop. At least if youre a tasty caterpillar trying to avoid getting eaten by hungry birds. Because a study in the journal Science

12、 shows that even young chicks tend to overlook caterpillars disguised as dung. Animals have come up with some pretty clever tricks for keeping themselves off a predators dinner plate. Some use camouflage, adopting colors and patterns that help them blend into the environment. Others masquerade as so

13、mething inedible, like bird droppings or twigs. But scientists got to wondering whether the two approaches are really so different. Maybe critters dressed as twigs also “blend in” so that predators just dont see them. To find out, scientists presented some twiggy-looking caterpillars to two sets of

14、hand-reared chicks. They found that baby birds that had never seen sticks before gobbled those bad boys right up. But chicks who were shown real twigs first took much longer to peck at the mimics, and did so more gingerly than their nave friends. That means the birds could see the caterpillars, but

15、were fooled by the costume, at least temporarily. Which, for a caterpillar on a leaf in the wild, could mean the difference between eating and being eaten.Karen HopkinAlan Alda Looks for The Human SparkThe Human Spark, a three-part PBS series hosted by Alan Alda and debuting January 6th, looks at wh

16、at makes humans the exceptionally unusual animals we are. Steve Mirsky reports January 6, 2010“For 11 years, I was the host of the public television series Scientific American Frontiers.” Thats the familiar voice of Alan Alda, star of stage, screen and science. Now Alda is hosting a three-part publi

17、c TV series about you. And me, and all of us. “Well be trying to get to the bottom of what makes us human. Trying to find that thing were calling the human spark.”One way to examine us is by looking at whats almost us. “Well be checking in with our closest living relatives, the chimpanzees, to find

18、out how the tiny difference in our genes, just 1 percent, makes such a huge difference to who we are and what we can do. Chimps are smart as a whip, but theyre not us. Why arent they?”The Human Spark debuts on PBS Wednesday, January 6th, with episodes two and three on the following Wednesdays, the 1

19、3th and 20th. “We cant promise well find the human spark, but we can promise that looking for it will be fascinating. And it may change the way you think about who you are.”-Steve MirskyAstronomys Serendipitious SideIn an article in the journal Science, Tufts University astronomer Kenneth Lang catal

20、ogues the discoveries about our universe that were made by happy accident. Karen Hopkin reports January 7, 2010Youve heard the saying “thank your lucky stars.” Well, in the January 1st issue of Science, astronomer Kenneth Lang of Tufts University says its not the stars that are lucky, but the folks

21、who study them. Because some of the biggest discoveries about our universe were stumbled on. Four hundred years ago, Galileo raised his homemade spyglass to the sky and spotted four of Jupiters moons, revealing that other planets could have their own lunar companions. Later, the planet Uranus and th

22、e first asteroid, Ceres, were happened on by scientists looking for other things. Again, improved instrumentation led to the finds. Which Lang says is a common occurrence in the world of skygazing. Gamma ray burststhose energetic explosions that are thought to herald the death of massive, far-flung

23、starswere first seen by satellites looking for covert use of nuclear weapons. And Wilson and Penzias discovered the cosmic microwave background radiation, physical evidence for the Big Bang, while fiddling with an antenna designed to catch radio waves bouncing off satellites. For realizing what they

24、 were actually measuring, they got a Nobel Prize. As Yogi Berra, a star himself, once noted, “You can observe a lot just by watching.”Karen HopkinMonkeys Are Canaries in Lead MineIn a study in the American Journal of Physical Anthropology, researchers showed that macaques that live side by side with

25、 humans in Nepal show elevated lead levels in their bodies. The human population is thus probably also being exposed to unsafe lead. Cynthia Graber reports January 8, 2010Youve heard about the canary in the coal mine. And frogs as signals of environmental degradation. The latest animal to serve as a

26、 harbinger of toxic exposures to humans may be: monkeys. Thats according to research in the American Journal of Physical Anthropology.Macaques live in close quarters with people in parts of Nepal. So scientists thought that the monkeys might be “sentinels” for human lead exposure. Lead can have mult

27、iple deleterious health effects, from impairing neurological development to kidney, liver, and circulatory and respiratory problems.The research team wanted to avoid stressing the animals, so they took a few strands of hair from individuals living around a temple in Katmandu. Its in a densely popula

28、ted area that contains old lead batteries, flaking lead-based paint, and lead-contaminated soil, a by-product of leaded gas. Lead levels varied in the macaques, but the highest concentrations were in the younglike human children, young macaques tend to pick up objects and stick them in their mouths.

29、Scientists say theyll next try to nail down whether macaque lead levels are indeed predictive of lead poisoning in humans. The hope is that monitoring macaque lead can improve conditions for humans and monkeys alike.Cynthia GraberShedding Light on MigraineEven some blind people are sensitive to ligh

30、t when enduring a migraine. In a study in the journal Nature Neuroscience, researchers studied blind people, and found a group of neurons that gets activated during a migraine, which could lead to treatments. Cynthia Graber reports January 11, 2010When people suffer from a migraine, they often retir

31、e to a cave-like dark room. But exactly why does bright light hurt the migraine sufferer? A possible answer was published this week in the online issue of journal Nature Neuroscience. A big clue was that even some of the blind migraine victims avoid light.Migraine pain is thought to come from irrita

32、tion of the meninges, membranes around the brain and central nervous system. So researchers took two groups of blind migraine sufferers. One group was totally blind. The other group was legally blind but could still make out light and dark.The totally blind group did not suffer from whats called photophobia. But light did aggravate the migraines of the legally blind group. Researchers thus suspected a group of light-sensing retinal cells that help regulate sleeping and waking, because these are the only active ligh