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Our World — 10 March 2007


This transcript is provided as a service; there may be some variation between it and the program as broadcast.

MUSIC: "Our World" theme

Straight ahead on "Our World," steering asteroids away from Earth ... research by very young scientists ... and the business side of wildlife habitats.

JOHNSON: "Habitat is the greatest factor in the control of the decline of species on the planet, so I think companies are realizing this is important for them to do."

Corporate property makeovers, great ideas on our Website of the Week, and more. I'm Art Chimes. Welcome to VOA's science and technology magazine, "Our World."

The U.S. space agency, NASA, said this week that it does not have the money to track the asteroids and comets that could potentially hit the Earth, even though it has the technical ability to do it.

Agency officials say it could cost a billion dollars to do a systematic survey of the skies and identify threatening objects that will cross Earth's orbit in the future.

The NASA announcement followed a recent symposium called "The Search for Killer Asteroids" at the annual meeting of the American Association for the Advancement of Science, where scientists discussed not just identifying the threat, but actually doing something about it.

More than 100 asteroids are now considered possible threats, including one called Apophis.

Steven Chesley of the Jet Propulsion Laboratory in California says that in 2029, Apophis is projected to come to within a few tens of thousands of kilometers from earth — alarmingly close by astronomical standards. Chesley says that while we'll be spared a collision that time, astronomers have determined that, if the asteroid flies through one particular area —

CHESLEY: "What we call a keyhole, a narrow slot, through which, if the asteroid passes, it will be deflected onto a course to rendezvous — in fact, collide with the Earth seven years later."

This is not just a theoretical worry. Asteroids have hit our home planet repeatedly. A century ago, a likely asteroid flattened 2,000 square kilometers in Siberia. And 65 million years ago, an asteroid estimated at just 10–15 kilometers across slammed into what is now Mexico. Then, it killed off the dinosaurs. Today, it could wipe out human civilization.

Chesley says there are an estimated 20,000 other asteroids still undiscovered that might threaten Earth.

So what happens if, one day, astronomers announce that they've discovered a distant asteroid heading right for Earth? Over the years scientists — and science fiction writers — have come up with various solutions. You've probably seen some of them in the movies. But a more elegant proposal comes from astronaut and physicist Ed Lu.

LU: "What it is, is a spacecraft that would hover near an asteroid. And what it would do is fire its engines to hold its position, and using the gravitational pull between them would, therefore, slowly tow the asteroid. Now it's a very small force, but you can hover there for a very long time. And the combined effect of a small force over a very long time can be enough to deflect an asteroid."

And when Lu says a very long time, he's talking about years, or even decades.

Still, when an asteroid is identified as being on a collision course with the Earth, it will be important to act as quickly as possible.

An asteroid collision may not happen in our lifetime, but former Apollo astronaut Rusty Schweickart stresses that we can and should be prepared.

SCHWEIKART: "With the early warning systems, and the technology, which as humans we have developed, we can prevent this. We can't prevent a hurricane. We can't prevent a tornado. But we can prevent an asteroid impact. Now, if we don't do that, we're not that far past the dinosaurs."

Which is why scientists stress the need to search the skies for asteroids that might be halfway across the solar system now, but which could pose a civilization-ending threat to Earth in the decades to come.

People who survive traumatic events — it doesn't have to be an asteroid collision — often experience a psychological condition called post traumatic stress disorder, or PTSD. Doctors have found that in adults with PTSD, there is an actual change in part of the brain called the hippocampus — it's smaller in people with PTSD than in people without. As we hear from health reporter Rose Hoban, there's new research on what happens to the hippocampus in children with PTSD.

HOBAN: Dr. Victor Carrion, a psychiatrist at California's Stanford University wondered if the same phenomenon occurred in children and if exposure to severe stress caused their hippocampi to shrink.

CARRION: "We're talking about interpersonal trauma and basically, what that is, is the experience of physical abuse, sexual abuse, witnessing violence, and these experiences tend to be severe, and they tend to be chronic. But anything really — man-made things like shootings, for example, or natural catastrophes like earthquakes."

HOBAN: Carrion and his colleagues evaluated 15 pre-adolescent children with symptoms of PTSD, including nightmares and uncontrollable flashbacks, extreme agitation and emotional numbness. They assessed the children's behavior at the beginning of the study and again, after 12–18 months. They also measured blood levels of the stress hormone cortisol and took images of their brains. They found kids with more severe PTSD symptoms had more cortisol in their blood and their hippocampi decreased in volume.

CARRION: "What that means is that the higher your symptoms of PTSD, or the higher your level of cortisol, the higher your chances of having a decrease in the size of this structure. So this is the first time that we're really seeing a connection, how cortisol might be related or affecting this structure."

HOBAN: Carrion says he was surprised at how quickly the changes occurred, even though the children were not experiencing trauma during the time of the study.

CARRION: "This is a trauma that they experienced in the past. So we're seeing the consequences of the trauma having an effect on the individual, not only the trauma."

HOBAN: Carrion says knowing about the physiologic changes in the hippocampus might help researchers understand why PTSD becomes a chronic condition and develop better treatments to help children. Carrion's study appears in the journal Pediatrics. I'm Rose Hoban.

Scientists have discovered a new group of genetic mutations they believe are responsible for triggering cancer growth in human cells. As VOA's Jessica Berman reports, the geneticists say their work will give cancer researchers a better idea of what they are up against.

BERMAN: In an article published in the March 7 edition of the journal Nature, scientists at the Wellcome Trust Sanger Institute in London report new cancer mutations.

Researchers focused on a family of proteins known as kinases.

Kinases have been implicated in human cancers because they regulate the behavior of cells, such as telling them when to live, die or divide. Cancer cells do not respond to the body's normal signals to die, and they grow out of control.

Mike Stratton is co-investigator of the cancer genome project at the Wellcome Trust Sanger Institute in London. He says researchers found approximately 1,000 mutations in the DNA of the cancer cells they sequenced.

STRATTON: "We find evidence for really quite a large number of new cancer genes. We find evidence for approximately 100 new cancer genes from within those 1,000 mutations."

Genetic mutations are structural alterations in the code of DNA that regulates normal cellular functioning.

Stratton and colleagues divided the 100 new cancer genes into "passenger" or "driver" genes. The passengers greatly outnumbered the drivers and had mutations that did not contribute to cancer in any significant way.

The drivers, on the other hand, caused cells to begin acting abnormally — a feature of cancer.

STRATTON: "Mutations that you find in cancer are like an archaeological record of what that cancer has been through in its lifetime. So the mutations can tell you about an exposure that that cancer cell has been through 25 years, decades before."

Senior co-author Andy Futreal says the study gives cancer researchers a more comprehensive view of the genetic changes that cause the disease in each of its different forms. And, he says that is likely to lead to the development of new and more effective drugs to treat cancer.

But Futreal concedes researchers have only scratched the surface in their quest for cancer genes, because the kinases make up approximately one-percent of the human genome.

FUTREAL: "We need to expand the numbers of tumors, the numbers of genes sequenced, the numbers of types of tumors. So I think it is all moving in the right direction."

The scientists expect that new, faster technologies to find DNA sequencing will help them expand their search for cancer mutations within the human genome. Jessica Berman, VOA News, Washington.

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

This week, it's a place where you can get audio and video recordings of some of the smartest people around, talking about politics and technology; religion, science and the arts; and speaking at places like universities, research centers and bookstores.

GRUBER: "Every day in cities around the world, brilliant ideas are expressed in public discussions. And you can't have access to it until now. We deliver that access to you."

Brian Gruber is the founder of, a new website devoted to bringing unedited speeches, symposia and other events right to your computer.

Fora is where you can watch Nobel Peace Prize winner Muhammad Yunus talking about ending global poverty, or former Secretary of State Madeleine Albright discussing the role of religion in American foreign policy.

There are lots of websites with online videos, but Gruber says that, in content and presentation, Fora is different.

GRUBER: "You're going to find only the very best in each category. We provide chapters, for example, for every event. So it may be that, here is a two-hour panel discussion [but] there's only three minutes that interest you. You can look at the chapter titles and find that. We have synchronized transcriptions for featured programs. You can post your own comments. You can download it in any format that you want to. And so we provide an environment for people that is really differentiated from anything else out there."

Some programs are audio-only, but most are video. Either way, you can download an MP3 to listen to on your computer or portable player.

Many of the presentations come from organizations that are already taping and webcasting their events, but if you've got a video camera you can contribute, too, and Brian Gruber hopes he'll get more material from all over the world.

Great ideas, and some really smart people on, or get the link from our site,

MUSIC: Willie Nelson — "Something To Think About"

And you're among the smart people listening to VOA's science and technology magazine, Our World. I'm Art Chimes in Washington.

One feature of pretty much any science conference is the poster session. Typically, it's a room full of display panels, with researchers having perhaps three square meters to present the words and pictures that will capture the attention of passersby and succinctly explain their work.

While presenting a poster may not have the high-profile visibility of giving a talk, it's still an honor to be part of a poster session and a recognition of the quality of your work.

At the recent meeting of the American Association for the Advancement of Science, the AAAS, in San Francisco, there was a poster session for senior researchers and another one for university students, but nothing was more impressive than the highly competitive session sponsored by the American Junior Academy of Sciences for teenage researchers.

BUZAN: "I'm Julia Buzan. I'm from Cherry Creek High School in Denver, Colorado. And my science research project has to do with estimating the quality of a violin based on common characteristics in their wood vibration."

Julia, a musician herself, set out to find an objective way of assessing the quality of a violin. She recognized that actually playing the violin would introduce too much variability to how she pulled the bow across the strings. So instead, she used a tuning fork to replicate the vibration of the strings, and she found that a $12,000 violin continued to vibrate much longer than a cheap instrument.

BUZAN: "And that makes sense if you think about the way in which really nice violins play in concert halls, how their sound is sort of piercing all the way to the back of the auditorium and how each note vibrates for a very long period of time."

Her poster explains the methodology and is full of graphs showing her results. At just 16 years old, Julia says she plans a career in medicine, and hopes to do humanitarian work in developing countries.

Nearby, two young scientists from the Midwest presented their research on the runoff of agricultural chemicals into local streams.

BURGESS: "My name is Haley Burgess. I am from Donnellson, Iowa. Central Lee High School."
HAWES: "My name is Shala Hawes and I'm also from Central Lee High School, and we did a team project together."
BURGESS: "And our project is about nitrates and phosphates in our local creeks and ponds."

With help from the University of Iowa Hygienic Lab, they designed an experiment to measure the chemical runoff in streams near farmland, and 17-year-old Haley Burgess says it was proportionate to the amount of land that drains into the stream.

BURGESS: "The largest amount of nitrates and phosphate was found in the largest creek, which also had the largest amount of watershed. So that creek had the largest amount of everything, where the smallest creek had the smallest amount of watershed, nitrates and phosphates and all that."

Haley's partner, Shala Hawes says they also learned that the traditional method used by area farmers to protect the waterways is not the most effective.

HAWES: "Most of the farmers in our area use grass buffer strips because they're the easiest to plant, but we actually found out that tree buffer strips are the most effective in filtering the nitrous and phosphates out of the water."

Shala is 16 and aiming for a career in anthropology. But she participates in a wide range of school activities and denies she is a "science geek."

I was impressed by the work of the teen scientists at the AAAS meeting. But that's not just my opinion. Listen to John Safko, physics professor emeritus and an official of the group that oversees the Junior Academy of Sciences.

SAFKO: "We have had research faculty go through our poster display, because it isn't always so clear that it's the American Junior Academy of Science, and think that they're looking at graduate papers. Our age group: we have one 13-year-old, and everyone else is 15 through 19."

Among the most professional presentations from these high school kids came from a couple of Vietnamese-American students.

RICHIE HUYNH: "My name is Richie Huynh and I'm from Champlin Park High School, in Champlin. Minnesota, and the name of my team project is 'Alzheimer's Disease, brain atrophy and immunohistochemical detections of neurofibrillary tangles using multiple antibodies.'"

I'm glad I didn't have to say that! Richie's partner and identical twin brother Ryan said they came to their research topic through a chance contact at an international science fair, and he said that Alzheimer's Disease is a satisfying topic to study.

RYAN HUYNH: "Well both of us wanted to do research that would be pretty significant to society, and Alzheimer's Disease is something that's very significant and is also very emotional and it affects people on many different levels, including personal levels, and so we thought we would like to do research on Alzheimer's Disease."

Both Ryan and Richie are aiming for careers in medical research, and they seem to have made a good head start. Meanwhile, as high school students, like many of the others here, they say a big challenge is balancing time-consuming research with the rest of their very busy lives.

Finally today ... About a quarter of all private property in the US is owned by corporations, and many of those corporations are seen as uncaring polluters. But some companies are taking the expensive landscaping around their corporate offices, factories and warehouses and turning some of that land into wildlife habitat.

For example, near a plant in Iowa, the Monsanto Company set aside a 200-hectare sand prairie. And just outside of New York City, Exxon Mobil is protecting 300 hectares as a habitat for birds like wild turkeys and wood ducks.

As Gretchen Millich reports, they are finding that the changes are good for the environment and for business.

MILLICH: Setting aside land for wildlife is becoming a big trend among corporations in the US.

Bob Johnson is president of the Wildlife Habitat Council. The council brings together businesses and environmental groups to conserve and restore natural areas. His group has helped set up hundreds of wildlife preserves at corporate facilities:

JOHNSON: "Most of our members are not recognized as being very green and I think that is really changing now because many companies are trying to find ways of being a lot more conscientious about materials and energy. But the real bottom line is habitat. Habitat is the greatest factor in the control of the decline of species on the planet, so I think companies are realizing this is important for them to do."

MILLICH: Johnson says there are lots of advantages to being green in the world of business. Studies show that employees are happier and more productive when they work for a business that shares their values. Also, it's much less expensive to maintain a wildlife habitat than to fertilize and mow grass.

Bridget Burnell works at a new General Motors assembly plant near Lansing, Michigan. Burnell is an environmental engineer. She oversees 75 acres on the factory grounds that's been set aside as wildlife habitat:

"What we're walking up to right now is the first major wetland that you come across. This is what all the employees can see as they are driving along the main road east of the plant."

BURNELL: It's an unlikely spot for a wildlife refuge: on one side a sprawling automobile factory, on the other, the intersection of two major highways. It's noisy, but still somehow serene.

MILLICH: Birds, turtles, muskrats, and frogs all live here undisturbed. A great blue heron is flying over the wetland and in the distance, we see three whitetail deer. Burnell says on nice days, teams of employees come here to take care of the grounds and sometimes they work with community groups:

"We've had about 20 events this year that we've had different community organizations out here. Some of it's directly related to educational type things, like learning about the wetlands and the prairie and different types of habitat. Others are specific to a particular project, maybe wood duck boxes or song bird boxes, that type of thing."

MILLICH: This factory is the only automotive plant to receive certification from the US Green Building Council for Environmental Design and Construction. GM saves about a million dollars a year in energy costs. And although there's no direct cost savings on a wildlife habitat, GM is finding that preserving natural areas can improve the company's image in the community, and also with its customers and investors.

Bob Johnson of the Wildlife Habitat Council says these wildlife projects are attractive to green investors, who choose stocks based on how a company deals with the environment. He says some investors believe that environmental responsibility is a reflection of how a business is managed. And a lot of that information is available on the Internet:

JOHNSON: "The individual on the street can do that today. They can evaluate this kind of information and make judgments. So I think people are looking for ways of distinguishing where they are placing their resources."

MILLICH: Johnson says since corporations are the largest group of landholders, they're in a good position to slow down the fragmentation of wildlife habitat. He says corporate leaders are discovering that with a little effort, they can win friends and gain a competitive advantage.

For the Environment Report, this is Gretchen Millich.

The Environment Report is a production of Michigan Radio. Support comes from the Joyce Foundation, the George Gund Foundation, and the U.S. Department of Agriculture. Have a comment? Send email to

That's our show for this week. We're always interested in your comments, or maybe you've got a science question. If you'd like to get in touch, email us at Or use the postal address:

Our World
Voice of America
Washington, DC 20237 USA.

Rob Sivak edited the program. Eva Nenicka is the technical director. And this is Art Chimes, inviting you to join us online at or on your radio next Saturday and Sunday as we check out the latest in science and Our World.