大家一起来听写Science News

lumao66UID: 2383330

督促自己，今后每天都把该网站的60-Second Science贴过来。

http://podcast.sciam.com/daily/sa_d_podcast_110614.mp3


Apart from working and sleeping, the thing Americans do the most is watch TV—5 hours a day on average. But all that time in front of the tube may up your risk of death, according to a review in the Journal of the American Medical Association. [Anders Grøntved and Frank Hu, Television Viewing and Risk of Type 2 Diabetes, Cardiovascular Disease, and All-Cause Mortality]

Researchers analyzed eight previous studies looking at the effects of TV on health. Together, the studies followed more than 200,000 volunteers over about a decade of their lives, and controlled for other risk factors, like age and smoking. The take-home? For every two hours of TV per day, subjects had a 15 percent higher risk of heart disease and a 20 percent higher risk of developing type 2 diabetes. That translates to a city of a million people having 1760 extra cases of diabetes compared to a city of a million who watch two hours less TV per day.

Previous studies have associated other sedentary activities, like sitting at a desk, with health risks. But the researchers say there's something unique about TV. Not only are we not exercising, but we tend to snack while watching. The prescription, in this case, is simple, and side effects are rare: get off the couch.
—Christopher Intagliata

doraliuUID: 2842061

顶~~~~

vent99UID: 2967082

紫霞姐姐在前面 ，顶！！！

lumao66UID: 2383330

http://podcast.sciam.com/daily/sa_d_podcast_110615.mp3

Climate change affects seasonal events—spring flowers open earlier, songbirds breed sooner. But what about mammals? A new study documents the effect on a special breed of cows in the U.K.

Northumberland’s Chillingham cattle were once domesticated, but now roam free. And they offer a unique opportunity for study. Because owners started keeping detailed records on them in 1860, due in part to the urging of none other than Charles Darwin. The cattle are thus an excellent source of long-term info on how earlier springs affect what’s called phenology—seasonal lifecycle events.
The Chillinghams can give birth all year, not just spring and summer like most U.K. mammals. And the data show that over the past few decades, there’s been an increase in winter births. Which the researchers correlated to warmer springs the previous year: plants grow earlier, the cattle have more access to nutrition and they conceive earlier.

But winter babies are more likely to die before they turn one. The research was published in theJournal of Animal Ecology. [Sarah Burthe et al., "Demographic Consequences of Increased Winter Births in a Large Aseasonally Breeding Mammal (Bos taurus) in Response to Climate Change]
The researchers say that even mammals that breed year round—which should offer protection against seasonal shifts—may still feel the impact of climate change.

chenyuanmeiUID: 2635161

very good!

doraliuUID: 2842061

紫霞姐姐在前面 ，顶！！！
vent99 发表于 2011-6-16 18:43

哈哈 乖~~~

doraliuUID: 2842061

今天再来听~~~~

lumao66UID: 2383330

http://podcast.sciam.com/health/sa_60sh_podcast_110621.mp3


There's nothing relaxing about sitting in a doctor's examining room, being poked and prodded while you’re wearing a stiff paper gown and a pair of socks that suddenly feel super awkward.

In fact, these routine checkups can give people with normal blood pressure what’s called "White coat syndrome," temporary high blood pressure brought on by the health care providers themselves. When that cold stethoscope hits the skin and the blood pressure cuff starts tightening around the bicep people may get a little anxious.

The rise in blood pressure can lead doctors to think a patient has chronic hypertension. And a new study finds that for two thirds of adults with verified high blood pressure, a single BP measurement was not reliable. The research is in the Annals of Internal Medicine. [Benjamin Powers et al., "Measuring Blood Pressure for Decision Making and Quality Reporting: Where and How Many Measures?"]

With most doctors taking just one or two readings, many people are likely being over-treated for hypertension. A more reliable method is to average several blood pressure measurements taken in the office, or at home—assuming you’re not being poked and prodded there too.
—Katherine Harmon

lumao66UID: 2383330

http://podcast.sciam.com/space/sa_60ssp_podcast_110620.mp3

The Voyager 1 spacecraft is poised to leave the solar system and reach interstellar space. In fact, it may already have.

Voyager 1 launched in 1977. It's now 17 billion kilometers from Earth. And it should be close to the heliopause, where the plasma flowing outward from the sun no longer holds back the interstellar winds.

The heliopause was expected to be a rather sharp boundary between the sun’s domain and interstellar space. But instead the spacecraft now finds itself in an unexpectedly tranquil zone. Voyager 1 no longer has the wind at its back, so to speak—since last year the velocity of the outward-flowing solar wind has been zero. And it has unexpectedly stayed that way for hundreds of millions of kilometers, according to a mission update in the journal Nature. [Stamatios Krimigis et al., Zero Outward Flow Velocity for Plasma in a Heliosheath Transition Layer"]

That could mean that Voyager 1 is drawing close to the heliopause, which just happens to be surrounded by a broad expanse of calm. Or it could mean that Voyager 1 has already crossed the heliopause. Either way, the spacecraft becomes the first object in interstellar space created by intelligent life. That we know about.
—John Matson

lumao66UID: 2383330

http://podcast.sciam.com/daily/sa_d_podcast_110622.mp3

Saliva contains many useful components. Lubricants. Enzymes for breaking down food. And now, compounds that can reveal a person’s age. That’s according to a study in the journal Public Library of Science ONE. [Sven Bocklandt et al,Epigenetic Predictor of Age]
During normal development, DNA in your body gets what’s called methylated. Small chemicals called methyl groups bind to the DNA, helping to determine which genes become active. But the patterns of methylation change as we grow older. Which was a clue that measuring methylation might give away age.
The researchers studied DNA in saliva contributed by 34 pairs of male identical twins, ages 21 to 55. They found 88 sites on the men’s DNA where the amount of methylation correlated with their ages. The scientists next verified that finding in 60 men and women, ages 18 to 70.
Then they narrowed in on two genes that had the strongest age-related correlation. And using just that data, they found that they could estimate the ages of their saliva contributors to within five years.
This technique might help in crime scene investigations—recovered saliva could tell the age of a perpetrator. So if you’re worried about anyone knowing how old you are, be careful where you spit.
—Cynthia Graber

lumao66UID: 2383330

http://podcast.sciam.com/daily/sa_d_podcast_110623.mp3

Birds and sea turtles can migrate thousands of miles, by reading the Earth’s magnetic cues. But we too might have magnetic sensing abilities—in our eyes. So says a study in the journal Nature Communications. [Lauren Foley, Robert Gegear and Steven Reppert, "Human Cryptochrome Exhibits Light-Dependent Magnetosensitivity"]
Previous studies suggest long-distance migrators—and even fruit flies—pick up magnetic fields with the help of a light-sensitive protein called "cryptochrome." We produce cryptochrome too—without it, our circadian clocks would break. Human cryptochrome doesn't require light to function, though—and it doesn't seem to give us a phenomenal sensitivity to magnetic fields. But can it do more than keep the circadian clock ticking?

To find out, researchers took out fruit flies' usual cryptochrome gene and inserted the human version. And the transgenic flies had no problem navigating a magnetic maze when exposed to light—indicating the human protein can still serve as a light-sensitive magnetic sensor.

We happen to have a lot of cryptochrome in our retinas—ideally situated to receive light. Which suggests we might be able to see magnetic fields in some way. On the other hand, evolution might have just given cryptochrome a new job in new organisms. So don’t throw away your GPS.
—Christopher Intagliata

doraliuUID: 2842061

赞lz~~~~

lz啊，要不把60s的日期也写出来？？这样清楚一些

any0UID: 3113569

很不错哦~~学习啦！！谢谢分享

lumao66UID: 2383330

12# doraliu
行，下回开始我加个日期。
之前因为每天听，所以感觉日期基本跟自己发帖的时间一致。

lumao66UID: 2383330

June 24, 2011

http://podcast.sciam.com/daily/sa_d_podcast_110624.mp3


Counting on food with fake fats to help you slip into last year’s bathing suit? Better count again. Because a new study with rats shows that low-cal fat substitutes can actually promote weight gain. The work appears in the journal Behavioral Neuroscience. [Susan Swithers, Sean Ogden and Terry Davidson, "Fat Substitutes Promote Weight Gain in Rats Consuming High-Fat Diets"]

Dieters can choose from an array of snacktackular options in which sugars and fats are replaced by artificial, low-calorie substitutes. That sleight of hand seems ingenious. You can let your body think it’s getting the sweets and fats it craves while keeping the calorie count to a minimum.

But the new study suggests that this strategy is likely to backfire. Rats that consumed a mix of full-fat chips and chips with olestra wound up eating more and got fatter than rats that noshed on regular chips alone.

Their bodies were apparently getting mixed messages. A mouthful of fat is usually a signal that calories are coming, and the body reacts by getting ready to burn fuel. But olestra, which tastes like fat, carries no calories at all. So the body soon learns to stand down in the face of fat. All fat. Even real fat. Because as Shakespeare almost said, a chip by any other name still swells your seat.
—Karen Hopkin