VOA标准英语2009年-Our World — 26 December 2009（在线收听）

VOA's weekly science and technology magazine

Art Chimes 25 December 2009

MUSIC: "Our World" theme
               
This week on Our World: How farming fits in the global warming puzzle ... a dinosaur that may have injected its victims with venom ...and a car that finds a parking place, then parks itself ...

HANEY:  "Once you say 'OK, activate it,' you can sort of take your hands off the wheel and it, using lasers to figure out what the distances are to the other cars and to the curb, can just maneuver the car in there perfectly."

Innovations of the year, the future of fusion power, and more.
 
I'm Art Chimes. Welcome to VOA's science and technology magazine, "Our World."

Left in the Cold at Copenhagen, Farmers Look to Future

In the run-up to the Copenhagen climate conference, many experts said agriculture should be a central issue in the discussions. After all, farmers are directly affected by climate change, they contribute up to a third of all man-made greenhouse gases, and they can also mitigate their impact by capturing excess carbon dioxide in the soil. As the dust settles in the Danish capital, VOA's Steve Baragona looks at what changes could be in store for agriculture.

BARAGONA:  Many farmers worldwide hoped that negotiators in Copenhagen would devise a way to shield them from the heat waves, droughts, floods, and other unpredictable weather predicted under climate change, and reward them for activities that trap greenhouse gases. But agriculture wasn't mentioned in the final accord signed December 18 by the United States, China, India, Brazil, and South Africa. That was a disappointment for Ajay Vashee, president of the International Federation of Agricultural Producers.

VASHEE:  "So it's basically back to the drawing board as far as agriculture is concerned."

BARAGONA:  Vashee says at least negotiators agreed on a framework for a possible future agreement that could include farmers. And experts note that agriculture is a relative newcomer to climate negotiations. By comparison, it took several years of talks before reducing emissions from deforestation received a pledge of financial backing in Copenhagen.

The details of that deal — how countries can earn credit for preserving and restoring their forests — are still sketchy, however. And the American Farm Bureau Federation, the largest farmers' organization in the United States, warns that incentives to grow trees could backfire if they lead farmers to plant fewer crops. That's according to the Farm Bureau's director of regulatory relations, Russell Williams.

WILLIAMS:  "People need to understand that there [are] going to be some trade-offs here. If you're taking this much land out of production, what's that going to do to food prices? They really need to find a way, if they're going to move forward with this stuff, to have these forestry and agriculture offsets harmonized so you don't have a perverse incentive to forest land that's going to feed people."

WASKOW:  "There are circumstances in which they could be in tension. But I think there are also ways in which they can also be very mutually beneficial."

BARAGONA:  That's David Waskow, climate change program director at the advocacy group Oxfam America. He says in some cases, introducing trees into cropping systems can improve yields while storing carbon.

WASKOW:  "We've seen that in areas like the Sahel, where farmers have increased tree cover and that's really been beneficial in terms of natural fertilizers, in terms of water retention. So there's actually quite a bit of synergy there."

BARAGONA:  Waskow says Oxfam is one of several organizations that prefer these kinds of ecologically-based solutions to the Western model of intensive agriculture using pesticides and chemical fertilizers.

There is a deep philosophical rift within the agriculture community on this issue. Those who say organic agriculture is the only way to go drew fire in Copenhagen from the Farm Bureau's Russell Williams.

WILLIAMS:  "You just have to stand up and say, hey, wait a second; it doesn't do anybody any good to denigrate Western agriculture. And no matter what you think, and no matter what you say, Western agriculture has become the most efficient land use for food. The United States feeds a whole heck of a lot of people."

BARAGONA:  And the world will have to feed a whole heck of a lot more people in the coming decades, experts say, even as a changing climate makes growing food more challenging. As climate change negotiations move forward, expect to see more sparks fly over the best way to reduce greenhouse gases while continuing to feed a hungry planet.

Steve Baragona, VOA News, Washington.

Researchers See Fusion as Promising Clean Energy Source

Beyond agriculture, the Copenhagen conference on climate change left most environmental activists disappointed by what they considered its failure to agree on measures that would achieve the goal of limiting a global temperature increase to just 2 degrees Celsius.

Proposals to reduce climate-changing carbon emissions has focused on renewable energy sources, such as wind and solar.

But another alternative that has been just out of reach for decades is nuclear fusion power. Using fusion to generate electricity has, in theory, significant advantages over other sources, such as fission power, the kind of nuclear energy that comes from splitting the atom. Fission is the kind of reaction that powers today's nuclear power plants. Fusion is the kind that powers the sun and stars.

BOYD:  "This opens up the possibility for an incredible new energy source that has no carbon footprint.

Richard Boyd is the science director at the National Ignition Facility in California.

BOYD:  "It's intrinsically safe, and furthermore the design parameters of this facility would burn up the leftover nuclear waste from weapons-grade plutonium or spent nuclear fuel or anything that we currently don't have a place to store, so it would be gone."

Fusion experiments at the National Ignition Facility are set to begin next year, when scientists will direct almost 200 super laser beams at a pellet of hydrogen fuel, compressing it so it becomes about seven times denser and hotter than the center of the sun, and triggering, they predict, an energy-releasing fusion reaction.

The National Ignition Facility is a government-funded lab, and Congress is keeping an eye on fusion research. At a hearing of the House of Representatives Energy Subcommittee, Dr. Riccardo Betti of the University of Rochester said a demonstration of ignition, which sets off the fusion reaction, could set the stage for fusion power development.

BETTI:  "Ignition will prove the physics of fusion. We haven't proved the physics yet, and then we count on the technology to move a lot faster and turn this physics success into making electricity."

There are a lot of scientific and engineering challenges in harnessing the sun-like energy of fusion. How, for example, do you keep something at a temperature of millions of degrees from burning up the equipment?  The best approach seems to be a container that uses magnetic fields to keep the super-hot fuel suspended. That's what scientists plan to do at ITER, an international research collaboration being built in France. It will be home to the world's largest tokamak, as the magnetic confinement vessel is called. The goal is to demonstrate the commercial feasibility of fusion power.

PRAGER:  "In the past 30 years we've progressed from producing one watt of fusion power for one-thousandth of a second to 15 million watts for seconds, and ITER will produce 500 million watts for 10 minutes and longer."

Stewart Prager heads the U.S. government-funded Princeton Plasma Physics Laboratory. He said high hopes for ITER rest on years of experiments, advances in material science, and computer simulations aimed at a sustained fusion reaction — something that has eluded scientists in the past.

Congressman Rush Holt (D-NJ), who is a physicist by training, says the potential benefits of fusion energy are too big to ignore.

HOLT:  "The promise of fusion, with essentially unlimited, globally available ingredients, with great environmental attractiveness, with no harmful emissions or high level radioactive waste, or connection to proliferation of weapons materials,  -- in other words, a technology well worth undertaking."

Despite the optimism of those engaged in fusion research, there is still no guarantee that the process can be perfected to deliver safe, reliable, and economical energy in the foreseeable future.

Website of the Week Features Trusted Drug Information

Time again for our Website of the Week, when we showcase interesting and innovative online destinations.

The global pharmaceutical industry has developed a vast medicine cabinet full of drugs that save lives and keep us healthy. But there are so many that it's often hard to keep them straight. For years, doctors have consulted a book called the Physicians' Desk Reference, or PDR, as a trusted reference, and now the publisher has adapted that go-to source for consumers online.

FOTSCH:   "PDRHealth.com is a consumer website that provides a trusted source of medical information, with a particular focus on pharmaceutical information."

Dr. Edward Fotsch heads the company behind PDRHealth.com, where you can get authoritative information about prescription drugs, over-the-counter medicines, and supplements, as well as reference material on diseases and other medical conditions, surgery, and interactive tools to help you learn more about your options.

FOTSCH:  "Those are tools that we provide so that consumers can educate themselves, either to be begin to start to get a sense of, perhaps, what kind of illness or malady they may have, and also so that they can sometimes get their arms around the fact that there's nothing terribly wrong with them in the first place."

PDRHealth.com is only a couple of years old, but already Edward Fotsch is looking forward to integrating the drug information that's on the site with patients' electronic medical records.

An authoritative source of information about medicines and medical conditions PDRHealth.com, or get the link from our site, VOAnews.com.

MUSIC:  Horace Silver — "A Prescription for the Blues"

It's Our World, the weekly science and technology magazine from VOA News. I'm Art Chimes in Washington.

Bird-like Dinosaur Used Venom Against Prey

Scientists say a new analysis of the fossil remains of a small, feathered dinosaur discovered in China a decade ago indicates that the creature might have used venom to subdue its prey before eating it. Researchers say that finding suggests that venom may be a more ancient predatory weapon than previously thought. VOA's Jessica Berman reports.

BERMAN:  Sinonithosaurus was a creature that lived an estimated 125 million years ago. Paleontologists say this bird-like dinosaur, or raptor, was about the size of a turkey, covered in feathers and equipped with sharp talons, which it used for climbing trees.

David Burnham, a paleontologist at the University of Kansas, says scientists discovered another interesting trait while studying a well-preserved fossil of Sinonithosaurus — sharp, fang-like teeth that would have enabled it to inject venom into its prey.

BURNHAM:  "Not only do we have the grooved teeth, we do have a channel for the duct work and then small areas where the venom may well up and feed the bases of these grooved teeth."

BERMAN:  Burnham is part of a team of U.S. and Chinese paleontologists studying Sinonithosaurus. He says it appears the raptor did not kill its prey directly by injecting it with venom.

Rather, Burnham believes the dinosaur's poison caused rapid shock, subduing birds with thick plumage after Sinonithosaurus plunged its fang-like teeth through their feathers.

Burnham says researchers concluded Sinonithosaurus used venom after researchers studied modern venomous creatures.

BURNHAM:  "In light of recent work done on the Komodo dragon found to be venomous, iguanas have found to be venomous, we just all of a sudden said, 'Well, that's what the grooves are for.'  So, we did some research and published on it."

BERMAN:  Paleontologists believe the appearance of venom began with the prehistoric ancestors of snakes and other reptiles.

But Burnham says it now appears that a common ancestor may be responsible for venom use in ancient reptiles as well as bird-like dinosaurs, such as Sinonithosaurus.
 
BURNHAM:  "I was just totally amazed to find this. And I think this may mean that venom is actually more widespread and primitive than previously thought."

BERMAN:  A description of the venomous dinosaur Sinonithosaurus is published this week in the journal Proceedings of the National Academy of Sciences.

Jessica Berman, VOA New, Washington.

DNA Tracking May Help Save Threatened Vultures

Vultures don't need venom — they're scavengers that feast on dead animals. Now, in some places, it's the vultures themselves who are dying. An American scientist is part of an international effort to save these massive scavengers, as we hear from reporter Ann Murray:

MURRAY:  It's hard to get too excited about an ugly bird that eats dead, rotting flesh. But vultures are amazing animals. They can eat 20 percent of their own body weight in one sitting. And they have digestive systems with special acids that will dissolve toxic bacteria and viruses. Meaning, vultures prevent the spread of killer diseases like rabies and anthrax when they scarf down the carcasses of sick animals.

KATZNER:  "With the meat goes the disease."

MURRAY:  That's Todd Katzner, Director of Conservation and Field Research at the National Aviary in Pittsburgh.

KATZNER:  "Vultures are in dire conservation straits in much of the world because of things like habitat loss, poisoning and now these new problems like diclofenac."

MURRAY:  Diclofenac is a medicine given to sick livestock in central Asia. Vultures that eat livestock carcasses with traces of the drug almost always die of immediate kidney failure. It took scientists some time to figure that out. Katzner's friend Vibhu Prakash, an Indian ornithologist, recognized the beginnings of this vulture die-off.

PRAKASH:  "This was almost 20 years ago that Vibhu started seeing vultures near Barrackpore, India. They were sitting in a tree with their heads hanging down .And eventually they'd just fall out of the tree and die on the ground."

MURRAY:  Since then, Indian white-backed vulture numbers have plummeted from 30 or 40 million birds to just thousands. This massive decline has left scientists scratching their heads about how many vultures are left in central and south Asia and other parts of the world. Because vultures move around a lot, it's been hard to keep track of individuals. There's never been an accurate total population count — anywhere. That's where Katzner and the National Aviary come in.

For several years, Katzner and his field team have been traveling to mountainous grazing lands in Kazakhstan and the northern plains in Cambodia . Katzner says the one place vultures reliably congregate is at feeding sites.

KATZNER:  "We ask people if any livestock have died .We drive up to those sites. Usually the vultures have been there. When vultures feed on the carcass they leave feathers everywhere. And when we go to the carcass, we're able to pick up sometimes 500 or 1000 feathers."

MURRAY:  Once the feathers are collected, Katzner's team extracts DNA from them to identify individual birds. The scientists will use this information to create population models. This new counting method is faster and more reliable than capturing, marking, and recapturing birds.

Before I leave the Aviary, Katzner points out an American black vulture. She's gobbling a breakfast of chick pieces and mice. Katzner hopes his work will help to keep other vultures happy and hungry. He says we all need 'em on the job as nature's cleanup crew.

For The Environment Report, I'm Ann Murray.

Support for The Environment Report on VOA comes from the Park Foundation, and the Gaylord and Dorothy Donnelley Foundation. You can find more stories, and post your comments, at EnvironmentReport.org.

Popular Science Magazine Highlights Innovations of the Year

The editors of Popular Science magazine are always on the lookout for cool products and technologies, and in their December issue they highlight 100 of the best innovations of the year. We spoke with the magazine's executive editor about some of their choices, starting with a high-tech version of one of medicine's oldest tools — the Littmann electronic stethoscope.

HANEY:  "Well, it's the first stethoscope that does more than rely on the doctor's ears. And so, built in to the stethescope is wireless, Bluetooth communication. And so, when the stethoscope listens to the heart, it can beam that information to a nearby computer, where software can analyze the sound signal and, within a minute, provide the doctor with that analysis."

Q:  And because it's electronic, you've got the ability to transmit that information to a specialist if need be.

HANEY:  "Exactly. And the hope is that this would cut down on the number of specialist visits that doctors have to prescribe now because they're just not sure whether or not the abnormality is something they should worry about."

Q:  I'm an urban guy, and I consider myself a pretty good parallel parker, but like everyone else, every so often you just can't get the car in the space. Ford has a a self-parking car, a better idea from Ford. How does that work?

HANEY:  "Yeah, this is one of those straight-out-of-science-fiction kind of ideas. There have been a couple of other companies that have tried this. What Ford has done is, using a sonar-based system, it can actually find you a spot. So as you're driving down the street, it's scanning, and when it detects a spot that's big enough for it to be able to park into, it let's you know so there's no more of that pulling up next to a spot and guessing, is this car really going to fit in there? And then, once you say 'OK, activate it,' you can sort of take your hands off the wheel and it, using lasers to figure out what the distances are to the other cars and to the curb, can just maneuver the car in there perfectly."

Q:  There are a lot of great products in the 'Best of What's New' in December Popular Science, but there is one really great picture, and that's showing a wrecking ball going into a brick wall, and on the other side there's this thin wallpaper that is keeping the brick wall together and not smashed up by the wrecking ball.

HANEY:  "What the X-FLEX wallpaper is, is  essentially a Kevlar weave. Kevlar is the very strong material that we're all familiar with; it's in bulletproof vests and that kind of thing. So this is a weave of that material, sandwiched between elastic polymer films. And the net effect is that when something happens to a wall, either from an explosion or from something hitting it, the wall will still fail, but all the debris and the pieces won't actually come through the wallpaper, so the people on the inside are just that much safer."

Q:  So in the 1967 film, The Graduate, Dustin Hoffman is pulled aside in this cocktail party and this older man has one word for him: plastics. Today I guess in our green world it's two words: 'mushroom styrofoam.'

HANEY:  "Yeah, that doesn't quite have the ring to it that plastics did, but this is a pretty amazing product. The idea is that this would replace the kind of packing material, the styrofoam or polystyrene that we often see. And the way that this is made is with a mold that's filled with organic material like corn husks, any kind of waste that we have. And then on to that mold is sprayed these root-mushroom cells.

"And they grow into this incredibly dense network of roots until they've filled that mold. And then we can just take and bake that mold to stop the growth, and it just assumes whatever shape it's been in. So it's incredibly light, it's fireproof, and it's completely organic. And because of the process of making it, it actually takes about one-eighth the energy that normal polystyrene takes to manufacture."

Q:  Well those are some of the ones I found of interest, Mike Haney. What interests you? Do you have a favorite?

HANEY:  "Well, the one that I'm most intimately familiar with is the Somnio shoes, And I just did the New York marathon in a pair of these, and I can attest to, they are truly one of the Best of What's New things. What's great about the shoes is they are customizable; they actually take parts of the cushioning out of the sole and make them swapable.

"And so there's actually about 11,000 combinations and you can dial in just the absolute perfect shoe for your stride and your weight and your size and really run pain-free because that's really the key for a lot of people to getting rid of the joint they think might just come naturally with running is in fact just being in the wrong shoes."

You can read about the other 90-plus Innovations of the Year as chosen by the editors at Popular Science magazine at their website. We'll have a link at our site, VOAnews.com.

That's our show for this week.

We'd like to hear from you. You can email us at [email protected]. Or write us at -

    Our World
    Voice of America
    Washington, DC 20237 USA

Our program was edited by Rob Sivak. Bob Doughty is the technical director.

And this is Art Chimes, inviting you to join us online at voanews.com/ourworld or on your radio next Saturday and Sunday as we check out the latest in science and technology in Our World.