60s Science---From everyday collection to environmental protection, think Green!

阿泰UID：209473

January 19, 2009 Gene Lowers Infection Chance By Changing Behavior
http://www.sciam.com/podcast/epi ... nce-by-cha-09-01-19


A new study with worms shows that some have a gene that helps them stave off infections. Not through some kind of biochemistry—but by changing their behavior.

Scientists were studying two strains of the roundworm C. elegans, one strain that is commonly used in the laboratory, another that was isolated in Hawaii. The laboratory strain got fewer infections than the Hawaiian strain. That’s because the lab worms have a particular version of a gene called NPR-1. But the way the gene works is a bit of a surprise. You might think that a gene involved in fighting infections must somehow enhance an animal’s immune response.

But you would be wrong. Because a current study, published in the January 16th issue of Science, shows that’s not the case. Instead, the scientists showed that the NPR gene found in healthier worms made them picky about their location. They stayed clear of places where oxygen is scarce. As it happens, those are the neighborhoods where bacteria hang out, including the bugs that can cause disease. So the gene made the worms prefer germ-free locales.

So, take a tip from a worm. If you want to avoid what’s out there this winter, just don’t go out there.

阿泰UID：209473

January 20, 2009  Bacteria Can Use Viruses To Spread Toxin Gene
http://www.sciam.com/podcast/epi ... -to-spread-09-01-20

For years, scientists and physicians have been up in arms about the rise in antibiotic resistance. Seems that many bacteria, devious buggers that they are, are able to share genetic information—including, say, the instructions for destroying penicillin. Well, if that’s not bad enough, scientists from the NYU School of Medicine have found that some bacteria can use viruses to help them pass along the recipe for their favorite toxin, results published in the journal Science.

Like humans, bacteria are also prone to infection by viruses. And most of these viruses—called bacteriophage, or phage for short—make their bacterial victims sick. Or even dead. But in the laboratory, the scientists discovered that Staphylococcus aureus, the bug that causes toxic shock syndrome among other things, can actually co-opt phage, using them to shuttle the gene for toxic-shock toxin to another bacteria, in this case Listeria. That’s doubly nasty, because Listeria on its own causes food poisoning, so if it added toxic shock to its repertoire, well, that would be one seriously bad bug. Whether Staph aureus can pull off this stunt outside the lab’s not clear. But in this particular battle, ya gotta hope the viruses come out on top.

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January 21, 2009 "We Will Restore Science to Its Rightful Place"

http://www.sciam.com/podcast/epi ... o-its-righ-09-01-21

Pres. Barack Obama:

“Our health care is too costly…and each day brings further evidence that the ways we use energy strengthen our adversaries and threaten our planet…

“We will build the roads and bridges, the electric grids and digital lines that feed our commerce and bind us together. We will restore science to its rightful place and wield technology's wonders to raise health care's quality and lower its costs. We will harness the sun and the winds and the soil to fuel our cars and run our factories. And we will transform our schools and colleges and universities to meet the demands of a new age…

“Our challenges may be new, the instruments with which we meet them may be new, but those values upon which our success depends, honesty and hard work, courage and fair play, tolerance and curiosity, loyalty and patriotism—these things are old. These things are true.”

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January 22, 2009 Does fMRI See the Future?
http://www.sciam.com/podcast/epi ... the-future-09-01-22
For decades, scientists have used an imaging technique called functional Magnetic Resonance Imaging, or fMRI, to chronicle the brain in action. But a study in the January 22nd issue of Nature suggests that fMRI might show more than what the brain is doing—it might reveal what the brain’s about to do.

fMRI studies assume that blood flow in the brain correlates with neuronal activity. Active brain cells need nutrients, which are brought to the cells by freshly oxygenated blood. But in the new study, scientists found that fMRI also detects increased blood flow in brain regions that aren’t active—but that may be in the near future.

The researchers trained monkeys to perform a specific visual task. And they found that, even when the animals were sitting in the dark waiting for the test to begin, fMRI nevertheless revealed an increased blood flow to the monkeys’ visual cortex.

The study suggests that fMRI data may be a lot more interesting than we thought. Scientists may be looking at their imaging data in a way that’s too simplistic. And fMRI may not be measuring exactly what we thought it did. What will they think of next? Maybe fMRI can tell.

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South Asia Brown Cloud Is Homemade
http://www.sciam.com/podcast/epi ... s-homemade-09-01-26
There's a huge, gunky brown cloud that lingers over south Asia and the Indian Ocean each winter. It’s been known to cause respiratory diseases and even cancers in India and China. But scientists didn't really know what was in it. Now they do. Researchers from Stockholm University and colleagues published the results in the January 23rd issue of the journal Science.

The cloud contains black particles called carbonaceous aerosols—basically carbon soot. The team used radiocarbon analysis to figure out what parts of the soot come from biomass and what comes from fossil fuels. Biomass typically comes from burning forests for agriculture or burning wood in stoves. And fossil fuel particulates come from sources such as diesel engines or burning coal.

The investigators were surprised to discover that a large percentage of the soot, from almost half to two-thirds, comes from burning biomass like wood and dung for cooking and heat, rather than from coal power plants. Scientists say the good news is that these particles only remain in the atmosphere for a few days or weeks at a time. So once societies can figure out how to reduce biomass burning, that brown sooty haze—and the illnesses it causes—might disappear.

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Eat Less, Remember More
http://www.sciam.com/podcast/epi ... ember-more-09-01-27
You may have noticed that as you get older, you start forgetting more stuff: like, where you left your glasses, or the names of your children. Well, if you’re fed up with those senior moments, put down that pastrami sandwich. Because a new study, published in the January 27th issue of the Proceedings of the National Academy of Sciences, shows that cutting calories actually improves memory in older folks.

Calorie restriction lets lab animals live longer. And these hungry critters tend to be healthier, too: with lower cholesterol, better insulin sensitivity, and even slower cognitive decline. But these diets can be draconian. And it hasn’t been clear whether they’d offer the same benefits to people.

In this study, scientists asked 50 elderly women to cut the number of calories they consumed by a third. After three months, the researchers found that the dieters were not only slimmer, but they were better than they had been at memorizing lists of words. They also had better insulin levels and fewer markers of inflammation, which suggests that keeping those things under control may help keep the brain fit. It’s one of the cruel ironies of aging: if you want to remember your favorite restaurants, the less you should eat at them.

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January 28, 2009  Horning In on Triceratops
http://www.sciam.com/podcast/epi ... riceratops-09-01-28
Triceratops, as the name suggests, were huge dinosaurs adorned with three horns on their heads. Scientists now say those horns may have been a sort of battle bludgeon. Andrew Farke is a curator at the Raymond M. Alf Museum of Paleontology in California. He became curious about that headgear. Farke and colleagues wanted to investigate whether Triceratops fought each other with their horns. Which posed a problem: obviously, we can’t go back in time to watch the animals interact. So the researchers resorted to some techniques out of a Cretaceous CSI.

They examined more than 400 museums specimens of Triceratops and another closely related one-horned dinosaur called Centrosaurus. They scanned the skulls for injuries around where Triceratops might have locked horns and wrestled. Their assumption was that if the horns were just for display, both species would show few scars.

But the Triceratops had 10 times more skull injuries than their Centrosaurus cousins. The most likely explanation is that they probably jabbed each other in the head while fighting. The researchers published their findings in the journal Public Library of Science ONE. They also caution that the horns could have served more than one purpose—perhaps fighting and flaunting.

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补January 23, 2009 Crickets Con Connubial Conquests with Chemistry
http://www.sciam.com/podcast/epi ... nquests-wi-09-01-23
As Valentine’s day approaches, remember, it’s the thought that counts. Just ask a decorated cricket. Because according to a study published in the January 21 issue of the journal Biology Letters, the nuptial gift that male crickets use to woo their women is just a handful of amino acids—in a whole lotta water.

Many insects use a food offering to win over a potential mate. For crickets, the giftbag serves to distract the female while the actual sperm transfer takes place. As long as she’s busy eating, she won’t reach around and remove that little packet of swimmers. And the longer she feeds, the more sperm will make it through. And, presumably, the more little crickets that male will sire.

But the male, of course, wants to get the biggest bang for his buck. So his goal is to minimize what he lays out in his token of appreciation. The solution? The cricket’s gift contains a small sampling of amino acids, mostly nonessential glycine, and 84 percent water. But those amino acids act as an appetite stimulant, which causes the female to spend more time enjoying her nutritionally empty snack. It’s a cheap gift, but it works. Because nothing says “be mine” like a gooey glob of glycine.

saavedroUID：2423190

瞻仰膜拜中~~~~   你等我先把基础实力提升后就跟你走哈~~~

saavedroUID：2423190

你现在每天都坚持听写一篇吗？

阿泰UID：209473

我每天都在练习，感觉确实不错，1分钟时间不长，刚刚好

水晶小鱼UID：2471655

楼主真好啊~太感谢了~

但想问下，你的文本是自己听出来的还是哪里获得的啊？:loveliness:

saavedroUID：2423190

靠真不敢相信你这个怪物~~~ 嘿嘿~~~  我看你听写的文本了，里面充斥着不少GRE词汇，你连这个都能听得出来~~~   怪物啊~~~！！！！

阿泰UID：209473

January 29, 2009 Wireless Networks Are Soft Virus Targets
http://www.sciam.com/podcast/epi ... t-virus-ta-09-01-29
We’ve all gotten e-mails warning us about nasty computer viruses. Maybe you even have antivirus software installed on your machine. Well, now scientists say that our wireless networks are particularly vulnerable to infection, especially in densely populated urban areas.

The use of Wi-Fi routers has become increasingly commonplace, as more people get online at home, at school, at the coffee shop. And these wireless networks are an excellent target for computer viruses, because they’re always on, always connected to the Internet, and don’t have specific software to protect them.

The scientists simulated the infection of real wireless networks in a handful of U.S. cities, including San Francisco, Chicago, New York and Boston. They found that the infection of just a small number of routers triggered an outbreak, with the virus spreading to tens of thousands of routers within a week, most within the first 24 hours. The results are published in the Proceedings of the National Academy of Sciences.

Wireless networks are weakened by a general lack of security, including a failure to change the default password. So if you want to keep your network virus-free, at the very least choose a password that’s hard to guess. Like Bosco.


问题，为什么是Bosco，有什么隐喻在里面吗，不解

阿泰UID：209473

January 30, 2009  New Brain Cells Get Time-Stamped
http://www.sciam.com/podcast/epi ... me-stamped-09-01-30
You probably remember exactly what you were doing when you first heard the news on 9/11. That’s because the brain has ways to file information so that things that happen at the same time are forever linked in our minds. Now a study published in the journal <i>Neuron</i> says that newborn cells in a structure called the hippocampus help us remember concurrent events.

The hippocampus is part of the brain that allows us to lay down new memories. And about ten years ago, scientists were surprised to find that new neurons pop up in this region every day, even in adult animals and people. But what do these new cells do?

Scientists turned to computer modeling to help them find out. They put in what they knew about the behavior of these new cells, which start out like puppies that get totally excited over every little thing, and eventually mature into more discerning members of neuronal society.

And they found that the hyperactivity of these excitable young cells, which react with great gusto to everything that goes on, could help stamp memories with a sort of “time code” that indicates which things happened together. So if you still remember what you were eating when you dumped your loser boyfriend, you can thank your newborn neurons.