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Our World — 17 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," trolling the oceans for DNA treasure ... the far-flung impact of air pollution ... and bionic body parts — they're not just science-fiction anymore.

HUMAYUN: "What we're trying to do is to take real-time images from a camera, convert them into tiny electrical pulses and allow patients to see."

Those stories, making do with less water, kids get involved on our Website of the Week, and more. I'm Art Chimes. Welcome to VOA's science and technology magazine, "Our World."

A new survey of microscopic marine life has identified six million new genes in samples of seawater taken from the western Atlantic, the Caribbean, and the South Pacific off the coast of Latin America.

It's the product of a round-the-world voyage by a scientific team led by Craig Venter, the man best-known for having developed technologies to speed the sequencing of the human genome. Lately, he's been trolling the oceans, turning up vast amounts of previously-unknown genetic material from micro-organisms.

As we reported on Our World last May, Venter had already found abundant genetic material floating in the Sargasso Sea, part of the Atlantic previously considered virtually lifeless.

VENTER: "I had the notion that we might find organisms in other parts of the ocean that were more abundant there than they were in the Sargasso sea. And by sequencing multiple sites we might be able to compile an actual sequence database of the ocean's genome."

The quantity and diversity of genetic material in the oceans has been the big surprise of the work. Venter says there were differences in samples taken as little as 300 kilometers apart, and there were variations linked to specific environmental characteristics of the water.

VENTER: "We found these based on temperature, salinity, a number of different factors. In fact, we can actually tell where in the ocean a sample derived from, totally by its DNA sequences."

That could be useful, he said, for determining where a ship took on ballast water.

To process all the genetic information and make it available to researchers, a huge database called CAMERA has been loaded onto a specially-built supercomputer. If you have a computer, it probably has one processor and maybe 100 gigabytes of disk space. CAMERA principal investigator Larry Smarr says this one has 512 processors and 100,000 gigabytes of disk space.

SMARR: "This is necessary because the diversity, the biodiversity that Craig's team discovered was so great that the tools that are going to be needed to dig out the biology from this are going to be quite sophisticated and take a very large amount of computing time."

Researchers can connect with the data over the public Internet, but it's also being made available over special high-speed links because of the huge amount of data involved. In addition to the actual genetic information, the database includes so-called metagenomic information, such as when and where the sample was obtained, environmental conditions, satellite images, and so on.

So what use is all this? Like any kind of basic research, it's hard to predict exactly what will come of it, but Shibu Yooseph of the Craig Venter Institute says one likely beneficiary will be the medical field.

YOOSEPH: "In our paper we're describing a whole bunch of new genes that help with repairing damage caused to DNA by ultraviolet radiation. You know, this could be sort of a starting point to figure out, you know, what are the pathways involved in repair, and that could lead to — who knows? — coming up with medicines that can deal with certain types of cancers, skin cancers, for example."

Craig Venter adds that even micro-organisms have defense mechanisms, and they often take the form of complex molecules that potentially could be replicated and harnessed for use as new antibiotics and anti-viral drugs, at a time when disease-causing microbes are developing resistance to established drug treatments and posing an ominous new threat to public health.

The scientists published their findings this week in the open-access journal PLoS Biology.

Severely polluted air has become the norm in many Asian cities today. Industry, power plants and motor vehicles are all part of the problem. And as VOA's Rosanne Skirble reports, scientists believe it has the potential to change weather patterns far beyond Asia.

SKIRBLE: Texas A&M atmospheric scientist Renyi Zhang studies tiny airborne particles known as aerosols that are suspended in the clouds. Some of these tiny particles, such as sea salt, are natural; but others, such as soot and sulfates, are produced when coal is burned.

Zhang says his research is the first to link Asian air pollution and changing Pacific weather patterns. He explains that the abundance of aerosol pollutants changes how clouds are formed.

ZHANG: "What we have found is that over the last decade, the amount of deep convective clouds has increased from somewhere between 20 and 50 percent."

SKIRBLE: These dense high-altitude clouds can be many kilometers thick and lead to more intense storms over the Pacific. Zhang and colleagues base their findings on satellite measurements from 1984 to 2005 and on computer climate models.

ZHANG: "If you introduce polluted aerosols into the model and you can reproduce the satellite cloud measurements, you can make the clouds deeper, more energetic and produce more precipitation."

SKIRBLE: Zhang says the storm track over the Pacific is a major weather event and part of a complex global weather system, vulnerable to change.

ZHANG: "Basically if you change this weather pattern over the Pacific region, it is very likely that you are going to change the weather patterns over the West Coast and Canada. The weather patterns will be altered."

SKIRBLE: Scientists are also concerned that the movement out of Asia of polluted aerosols could affect climate at the Earth's poles. As more soot in the form of black carbon collects on ice packs, it attracts more heat from the sun and could accelerate melting.

Bill Chameides, a senior atmospheric scientist with the non-profit Environmental Defense, says while the Texas A&M study focuses on Asia, the region is not alone in sending its pollution around the globe.

CHAMEIDES: "I think that it is also important to bear in mind that there is a good deal of pollution that comes from the United States that has an impact on our weather and our air quality and also has the potential to have an impact for example, if China's pollution is having an impact on us, our pollution has the potential for having an impact on Europe."

SKIRBLE: Zhang says more research must be done to further evaluate the interaction between clouds and aerosols and what effect that might have on climate change. The Texas A&M study is published in the Proceedings of the National Academy of Sciences. I'm Rosanne Skirble.

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

This week we feature a site that gives young people from different countries and cultures a place to meet online, but this isn't your usual social networking site.

GALLEGOS: "Voices of Youth is an Internet site created by UNICEF for young people who want to know more, do more and see more about the world. It's about linking children and adolescents in different countries to explore, speak out and take action on global issues."

Maria Cristina Gallegos is coordinator for the Voices of Youth website at

The site is full of information of interest to young people; the target age group is 10 to 24. Voices of Youth includes articles on subjects such as the environment, poverty, and more:

GALLEGOS: "There is education, HIV/AIDS. Children's rights is also a very important topic because not everybody knows their own rights, so it's very important that they learn about their rights."

But Voices of Youth is not mainly about giving information to kids. Some 30,000 members from all over the world participate in online conversations.

GALLEGOS: "Well, the discussion forum is the heart of Voices of Youth. It's where kids can give their voice, submit their ideas, meet other people and partner so that they can do something about the issues that they're going through."

Remarkably, 60 percent of users are in developing countries, where computers and Internet service are less widely available. The site is in English, French and Spanish; and Arabic was added just last year. And there's no fancy animation or graphics, so it's very useable on a slow-speed Internet connection.

UNICEF's Voices of Youth. Check it out at, or get the link from our site,

MUSIC: Johnny Cash — "Forever Young"

And young or not, you're listening to VOA's science and technology magazine, Our World. I'm Art Chimes in Washington.

Ever wonder why some people you know tend to be grouchy, while others have a sunny disposition? Psychologists have long wondered the same thing. As we hear from health reporter Rose Hoban, there's some new research that could provide an answer.

HOBAN: One school of thought holds that people are just born that way and that these personality traits don't change … people bounce back to their natural happiness level after adverse as well as exhilarating life events.

But new research from Michigan State University's Richard Lucas indicates that some life events do have the potential to change us and make us happier — or unhappier — permanently.

Lucas and his colleagues analyzed large surveys from Germany and Great Britain started by economists in the 1980s. Over the years, the surveys asked tens of thousands of people about their level of satisfaction with their lives. They also gathered information about the subjects' life events.

LUCAS: "So for example, we can look at people who start out married, get divorced at some point and stay divorced, and we can compare their happiness before and after the divorce to see whether that life event is associated with any lasting changes and then this tells us, using pretty strong methodology, whether or not life events are associated with any permanent changes in happiness."

HOBAN: Lucas looked at events such as marriage, divorce, losing a spouse or becoming disabled.

LUCAS: "We found for the one positive event that we were looking at, marriage, there we did find adaptation, within two years, people adapted back to their original level of happiness."

HOBAN: In other words, the honeymoon glow eventually mellows. But, Lucas says, negative events tend to produce a more permanent change … and people become unhappier and less satisfied with their lives.

LUCAS: "So people who experience the divorce seem to be lower in their level of happiness after the divorce than they were before the divorce, and people who became disabled were much lower after their disability than they were before the disability. People who got widowed they did come back close to their original baseline level of happiness but it took a long time, about 7 years for them to return to where they were before they lost their spouse."

HOBAN: However, Lucas says these statistics don't account for individual differences in how people react to life events. He says one possible avenue for further research could be to identify events that tend to make people happier, permanently. The research appears in the April issue of Current Directions in Psychology. I'm Rose Hoban.

MUSIC: Six Million Dollar Man theme

In the 1970s you might have followed the thrilling story of astronaut Steve Austin, whose body was rebuilt by doctors after it was shattered in a terrible accident.

OK, it was a TV series called "The Six Million Dollar Man." Steve Austin, played by Lee Majors, got bionic implants that gave him strength, speed and vision far beyond normal capabilities.

Three decades later, science is catching up.

For example, one of the leading causes of blindness among older adults is macular degeneration, and there is no cure.

The condition affects the retina, the light-sensitive part of the back of the eyeball. So why not bypass that area and hook up a camera directly to the optic nerve?

HUMAYUN: "And what we're trying to do is to take real-time images from a camera, convert them into tiny electrical pulses that would jump-start the otherwise-blind eye and allow patients to see."

Mark Humayun of the University of Southern California has developed a device that includes a tiny camera, placed discretely on a pair of eyeglasses, that sends images to a receiver that is actually implanted inside the eye. Humayun says six patients have been using the device for as long as five years. Even with only 16 pixels, the patients report a surprising increase in their visual capabilities.

HUMAYUN "We expected that all we would see is just light and dark, but the subjects can differentiate in a test environment between a cup, plate, and a knife. They can tell motion around there, they can tell large objects so they don't stumble into them, and this is all very surprising because it's not what we expected and again it really speaks to the brain's ability to be able to fill in a lot of the missing information."

The researchers are now working on a 60-pixel version, which they hope will give even better results.

Humayun was one of several researchers working on restoring functions lost to age, accident or war who discussed thier work at the recent annual meeting of the American Association for the Advancement of Science. Another was Roger Narayan of the University of North Carolina.

NARAYAN: "There's a current demand by patients and clinicians for devices that fit patient geometry, specific patient conditions. So the idea is to use novel materials — whether it be ceramics, polymers or metals — and novel, rapid-prototyping technologies to create devices that fit the particular patient."

Narayan said such custom treatments can help, whether the patient is a soldier being fitted with an artificial leg or a child with a congenital deformity.

For those of us at the AAAS meeting, nothing was more impressive than the demonstration given by Jennifer French. She's not a scientist. She's a young woman sitting in a wheelchair, paralyzed from a snowboarding accident. She presses a button on a control box strapped to her waist ... and then she stands up.

FRENCH: "So here you see the functional benefit and the fact that I can stand out of my wheelchair. I can reach for things I usually can't reach. I can move around into spaces where the wheelchair wouldn't fit. And I can transfer onto spaces that wouldn't otherwise be able to transfer onto."

In the case of a spinal cord injury like Jennifer French's, the leg muscles, for example, aren't damaged. They just don't receive a signal from the brain telling them what to do. The system developed by Hunter Peckham and colleagues at Case Western Reserve University bypasses the injured part of the nervous system and applies an electrical stimulation to replicate the signal that the muscles no longer receive.

There are real benefits to a system like this, which is still experimental. There's less risk of medical complications, and of course there's an enormous psychological boost. Jennifer French was married a few years ago. Like many American brides she wanted to walk down the aisle at her wedding, not roll down in a wheelchair. And two years after she got her implant system, despite a spinal cord injury that put her in a wheelchair, that's exactly what she did.

Farmers growing food use an estimated 70 percent of the planet's limited supply of fresh water. But the need for these irrigated crops is coming into increasing conflict with the fresh water requirements of cities, factories and a healthy environment. American farmers and scientists are trying to tackle the dilemma, as Shelley Schlender reports:

SCHLENDER: It's been a wet winter in Colorado. For the first time in many years, Dave Petrocco says the soil needs to dry out.

PETROCCO: We're about a month late this year. It's time to put the crops in that we normally do this time of year, such as the spinaches, lettuce, onions, sweet peas."

SCHLENDER: With almost 1,000 hectares to be planted, the third generation farmer says it's hard to wait. But as he gazes across an empty brown field, he adds that too much water is a rare event.

PETROCCO: "Water, we're on an irrigated desert, and water has become an extremely precious resource."

SCHLENDER: To prepare for that unavoidable summer day when the soil will be too dry, Petrocco's been installing more drip irrigation. It's expensive, but it uses 40 percent less water than traditional flood irrigation. That's important because, over the years, his annual water allocations have been cut back.

PETROCCO: "However with the drip irrigation, it allows that farm to produce as it once did."

SCHLENDER: In the U.S., states monitor water use and distribution. Petrocco's water allocation has been trimmed due to growing competition between Colorado's cities and farms. By 2025, it's likely that every state in the nation will face the same crisis. That's according to experts at the American Association for the Advancement of Science annual meeting, held recently in San Francisco.

One way to reduce these conflicts is to develop plants that can tolerate saltier water, or less water. A new variety of drought-tolerant rice should be available soon, but John Bennet, with the International Rice Research Institute in the Philippines, says there will be trade-offs.

BENNET: "Rice roots tolerate submergence, and water can therefore be used to control weeds. Now, in monsoonal Asia, there was no shortage of water during the wet season. So it made sense to grow a crop and use water as a natural herbicide."

SCHLENDER: For rice in dryer fields, farmers may have to increase herbicide use or weeding.

Another approach is to make every drop of water count.

But here, too, are trade-offs, according to Ray Hoffaker, an economist at Washington State University. He warns that when a farmer uses a water allocation more efficiently, it can rob downstream water users. He says it's happened in Idaho.

HOFFAKER: "They're calling it the invisible drought."

SCHLENDER: It all began when farmers in northern Idaho replaced flood irrigation with high efficiency sprinklers. The change produced more food per hectare with less water. But it also made for a horrible surprise… because the run-off water was never really wasted.

HOFFAKER: "What happened was, the water from the flood irrigation was filtering down, recharging the aquifer. The aquifer was charging springs. And now since the switch to the higher efficiency systems, Idaho has an invisible drought, where the cities relying on that spring water are now not able to fill their rights, dairies are not able to fill their rights. Fisheries not able to fill their rights. The Idaho legislature is having to appropriate three million [dollars] a year to buy new water to fund the water usage in Southern Idaho."

SCHLENDER: That's why many western states, including Colorado, strive to control consumptive water use. For instance, if a farmer switches to more efficient irrigation, using less of his allocated water, most states will not allow that leftover water to be sold to another user, such as a city… reducing any economic incentive to become more efficient.

But some farmers may have no choice but to increase efficiency. As the needs of downstream users become more apparent, some irrigation water has been diverted. That's what happened recently to many Colorado farmers whose irrigation wells were approved half a century ago. Because these wells have reduced the flow in Colorado rivers, the state has ordered hundreds of them to be shut off.

In much of the West, the longer that someone's had a water allocation, the more likely that they can hang onto it. So as a third generation farm with water rights that date to the 1850s, Petrocco Farms has not been part of these massive shut-offs.

SCHLENDER: But as a truck brings in a tractor to help with the new spring plantings, Dave Petrocco worries about the future of farming in Colorado.

PETROCCO: "Every year in our area, here in Colorado, there are fewer farmers."

SCHLENDER: He says that for the sake of growing crops, and also serving communities, it's important to keep looking for ways that everyone can do more, with less water. For Our World, I'm Shelley Schlender in Brighton, Colorado.

MUSIC: "Our World" theme

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.