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Our World — 6 January 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," genetically-modified cattle made safe from mad cow disease ... helping the elderly avoid falls ... and one man's quest for energy independence ...

STRIZKI: "This is a much better solution than digging big holes in the ground, throwing sulfur up into the air. This is something that's definitely sustainable. We just have to have the will to do it."

Do-it-yourself hydrogen power ... also, the Mars rovers' third anniversary, and more. I'm Art Chimes. Welcome to VOA's science and technology magazine, "Our World."

They've got some new kinds of cows out in the American heartland. They look and act like any other cattle, but they have been genetically modified so they don't have the protein responsible for mad cow disease.

The protein is known as a prion, an oddly-formed molecule that can trigger a shape-shifting chain reaction among normal proteins that leads to the destruction of brain matter. The result in cattle is bovine spongiform encephalopathy, BSE, better known as mad cow disease. Veterinarian Juergen Richt says similar diseases occur in other animals, including humans, where the brain-wasting condition is known as Creutzfeldt-Jakob disease

RICHT: "These are related diseases, and the symptoms are always neurological signs — so, loss of ability to stand up, to walk — and they're always fatal. And also, when we look post-mortem, after the death of an animal or human, into the brain of them, you will find a loss of brain substance, so loss of neurons, etc."

Dr. Richt is with the National Animal Disease Center, part of the U.S. Department of Agriculture. He is one of a team of scientists who has just announced the development of cattle that have been genetically modified to be free of BSE. Lead researcher James Robl explains that he and his colleagues attacked the problem at the source.

ROBL: "And so our view was that if we go in and genetically knock out the gene that codes for that protein — and 'knock out' simply means that we insert a gene sequence that stops the gene from functioning. In doing that, we have prevented these cows from making the prion protein. And therefore, they should not be susceptible to mad cow disease."

Robl is president and chief scientific officer at Hematech, a biotechnology company based in South Dakota.

Mad cow disease, or BSE, was first identified in Britain 20 years ago, according to the World Health Organization. The vast majority of some 186,000 animal cases tallied by the WHO are in Britain, with other cases mostly in Western Europe.

Laboratory tests indicated that the modified cattle are immune to mad cow disease, but in a more real-world experiment, several of the living animals were injected with a prion agent to simulate BSE exposure. So far there have been no ill effects, but Juergen Richt says monitoring of the cattle is continuing.

RICHT: "Since prion diseases are rather slow diseases, it takes years from the time of infection until they develop clinical signs, these studies are long-term studies."

The genetic change to a prion-free animal may protect against mad cow, but Dr. Robl of Hematech says it was important to find if knocking out the prion gene had any unforeseen consequences.

ROBL: "But the real question was, what happens to the cows? And so we've been monitoring these cows in great detail for the last two years. And in summary, we've not found anything that appears to be different between the prion knockout cows and normal controls."

Beef cattle normally go to slaughter before age two, but dairy cattle and bulls kept at stud live much longer, and Richt said they are continuing to keep tabs on the genetically modified cattle.

But the researchers say they don't plan to breed prion-free cattle for food production. They mention that measures already taken to protect the food supply have minimized the risk of getting mad cow-, or BSE-infected products into the human food pipeline. And there are also regulatory obstacles, as American officials have been somewhat cautious about allowing genetically engineered food production — although not as cautious as some critics would like.

Anyway, Dr. Robl's company, Hematech is in a different business.

ROBL: "Our primary interest is that we are wanting to produce human pharmaceutical products from cows, and we want to make sure that there is no risk of transmittance of BSE in that particular case. The other thing is that cows are used for a variety of applications in the biotechnology industry, so there is concern about using serum from just any old cow."

In addition, the researchers say the genetically-modified cattle can be used as a experimental subject for further research on mad cow and related diseases. Their work appears in this month's issue of "Nature Biotechnology."

Three years ago Wednesday, a robot explorer called Spirit bounced onto the Martian surface for what was designed to be a three-month expedition. Three years later, Spirit, and its companion Opportunity, continue to explore the Martian surface and send back pictures and other data. Although they show signs of age, VOA's David McAlary reports that new computer software has given them expanded capabilities, proving you can teach an old robot new tricks.

McALARY: It was January 3, 2004, when the exploration rover Spirit plunged through Mars' atmosphere in a protective balloon-like cocoon and bounced to a stop inside a crater.

As an expectant team of scientists and engineers waited tensely at the Jet Propulsion Laboratory in California, mission controllers followed its trajectory.

ROVER MISSION CONTROL: "A signal indicates we are bouncing on the surface of Mars. [CHEERS] This is a very good sign." [MORE CHEERS]

McALARY: Three weeks later, the rover Opportunity did the same on the other side of Mars.

The U.S. space agency NASA had thought that the planet's extremely frigid temperatures and dust storms would keep their lives short. But rover project scientist Albert Haldemann notes that they have far exceeded their planned lifetime.

HALDEMANN: "We expected some extended mission lifetime. We designed the warranty for these rovers for three months on Mars and we tested for nine months. So one might expect that we would have gotten nine months for free, and here we are at three years."

McALARY: The twin rovers' major findings came within the first 90 days. Opportunity found chemical evidence in bedrock that a shallow salt water sea existed at some time in Mars' past. Spirit drilled into volcanic rocks and found minerals suggesting they had been carried by water and collected in the lava's tiny pores as it hardened.

Albert Haldemann says the inspection of the bedrock has been key to understanding Mars' evolution.

HALDEMANN: "And that tells us that Mars is a diverse place, that there are significant differences on these two sides of the planet where the rovers are, that Mars has complex geology, not unlike Earth in that sense."

McALARY: Since their early days, Spirit and Opportunity have roamed seven and 10 kilometers respectively past their original landing sites.

The rovers are going about their work reinvigorated with new navigation software uploaded into their computers. One of the technicians who guides the rovers, Scott Maxwell, says the improvements have made them smarter and more independent.

MAXWELL: "They are now better than they used to be at finding their way through fields of obstacles. They can keep an eye on something as they are driving and make sure that they get close to that particular thing because it is an interesting science target. They have figured out how to watch the skies for clouds or watch the terrain for dust devils blowing by, and when they find those and they know those are interesting to us, to send back data on those. They have gotten smarter just as we have gotten smarter."

McALARY: The rovers have some mechanical wear and tear, but nothing serious enough to stop them. Albert Haldemann says they have just survived another Martian winter and believes that if dust storms do not block the sun's energy and cause the batteries to die, they could last another 18 months until the next Martian winter. David McAlary, VOA News, Washington.

Mars is also the subject of our Website of the Week, in which we showcase interesting and innovative online destinations.

At, you can not only review the latest scientific discoveries from the Red Planet, but you can explore the geology, climate, moons and the possibility of life on Mars.

COWING: " is a daily compilation of news regarding the planet Mars. It's a series of status reports, press releases, news stories, photographs and so forth. I tried to pick a niche where I thought we could be most useful, relaying information and news about Mars, and trying to pick the best of the best."

Keith Cowing is the editor of, one of a network of websites on various aspects of space and space exploration. The site presents a wide range of information about Mars from various sources, and he says it's important that visitors know where the information comes from.

COWING: "We try to make certain that people know exactly what it is they're reading. If it's a press release, it says press release. As far as the images go, we make certain that people can see a small version but then go directly to the source imagery. So we're very focused on making sure that people get the information in the most accurate and traceable format that we possibly can provide."

Mars has long had a special place in the imagination of we Earthlings. In science fiction, such as H.G. Wells' classic War of the Worlds, the alien invaders always seem to come from Mars. And is the first space website I've seen that has links to some of the vast science fiction literature about Mars right alongside the latest pictures from the Mars rovers.

COWING: "When you eventually arrive at a place physically, many people have already been there in their minds, whether it's imagining things or putting their imaginary trips into writing. And oftentimes how we've imagined a place affects how we explore it and what we think of it. So the idea of exploring Mars is clearly, of all the planets, one of the ones that has been most visited in flights of fancy."

Lots of Mars stuff, including an email newsletter and RSS feed you can subscribe to, at, or get the link from our site,

MUSIC: "Conjunction Mars" — Hank Crawford

It's the invasion of VOA's science and technology magazine, Our World. I'm Art Chimes in Washington.

And one more space story today. Scientists report this week that they have discovered lakes on Saturn's largest moon, Titan. But I don't think we would recommend planning a fishing or swimming trip there. Instead of water, the lakes are most likely full of methane.

The discovery comes from data relayed back by NASA's Cassini space probe, which flew past Titan in July. Scientists identified 75 probable methane lakes in radar images of Titan's northern regions. Cassini team member Ellen Stofan says the geography resembles places where lakes are found here on Earth

STOFAN: "They have channels feeding into them, just like you have rivers feeding into lakes on the Earth, the shapes of them, their shorelines, all of those geologic aspects of the lakes are actually very familiar."

Scientists are particularly interest in this moon of Saturn because Titan's atmosphere is, like Earth's, mostly nitrogen, but with a lot of methane, too — like that of the early Earth before oxygen became abundant. And now there's evidence that methane on Titan acts like water does on Earth.

STOFAN: "Titan is right now really the first body in the solar system that we've been to that has an active, fluid, liquid cycle. On the Earth here, it's the hydrologic cycle. We almost have to make up a new word for it on Titan, it's the "methane-ologic cycle." But it's the first place where you have rain, you have erosion, you have lakes — they probably vary seasonally. You know, obviously at some point in the past, Mars had that, but on Titan, it's happening right now, and that's extremely exciting from a scientific point of view."

Details of the work were published in this week's issue of Nature. A separate commentary notes that Ellen Stofan's paper provides further strong evidence that methane plays the same role on Saturn's moon as water does here on Earth.

Scientists here in the West often toast their achievements with champagne or another festive alcoholic beverage. When taken in moderation, there is an increasing body of evidence that alcohol need not be harmful. Here's VOA medical correspondent Jessica Berman with details of a new study, published in the Annals of Internal Medicine.

BERMAN: The scientific evidence continues to mount, and it is all good, that moderate alcohol consumption is beneficial.

The latest study focuses on men with high blood pressure who are at significant risk for heart attack. Often, doctors tell such patients, among other things, to quit drinking.

But when U.S. and Dutch researchers analyzed data from about 12,000 men with high blood pressure in the Health Professionals Follow-up Study, sponsored by Harvard University and Beth Israel Deaconess Hospital in Boston, the investigators found that moderate drinking might not be such a bad idea.

Every four years during the 16-year study, which began in 1986, the male health professionals were questioned about their daily alcohol consumption.

Study lead-author Joline Beulens of the TNO Quality of Life Institute in the Netherlands says fit men who drink one to two drinks per day of wine, beer or spirits had a decreased risk of having a heart attack.

BEULENS: "And we further looked at risk of heart disease or death due to other causes and we could not find any difference between men that drank moderately and men that did not drink at all."

BERMAN: But Beulens says too much alcohol, equivalent to three or more drinks per day, increases the risk of developing high blood pressure.

Beulens says more studies are needed to see whether moderate drinking reduces the risk of heart attack in women. Jessica Berman, VOA News, Washington.

As we age, our bones lose mass, which increases the risk of broken bones. A common scenario involves an older adult, perhaps in her 70s or 80s, falling, breaking her hip, and never fully recovering. VOA's Rosanne Skirble has a report on a new study of ways to avoid a fall in the first place.

SKIRBLE: Researchers at the University of Michigan compared two techniques already proven to improve balance among the elderly. One is tai chi, an ancient Chinese practice involving slow fluid movements. The other, says University of Michigan professor Neil Alexander, is a method called Combined Balance and Stepping Training or CBST.

ALEXANDER: "This would involve doing two tasks at once, such as carrying an object while walking or such as stepping over an obstacle. The other piece of balance training that we have added in this study is stepping training, where the older adult was trained to improve the speed and length of their step."

SKIRBLE: The study divided participants into tai chi and CBST classes. Alexander says after attending 3 classes a week for 10 weeks, those doing CBST showed a 5-10 percent edge in balance, stepping and walking tasks over the tai chi group.

ALEXANDER: "I consider this a modest effect, but nevertheless an important one because the Combined Balance and Stepping Training trains at a speed which is more akin to what is necessary to avoid a fall."

SKIRBLE: In other words, the CBST exercise movements are faster than tai chi. Alexander says while both techniques improve mobility and balance, it’s the pace and stepping practice that gives CBST an added advantage.

ALEXANDER: "So that when you respond in a near fall situation, you need to respond not just quickly but with an adequate step length that is sufficient to keep you upright."

SKIRBLE: Alexander hopes the study can help influence the design of an exercise program that can reduce the risk of falls. Alexander advises consulting with your doctor before embarking on any new exercise program.

The study is published in the Journal of the American Geriatrics Society. I'm Rosanne Skirble.

And finally today, many homeowners have reduced their fossil fuel consumption by placing solar panels on their rooftops. But one man has taken it a step further. He's created a homemade power plant that runs on solar power and hydrogen fuel cells. Brad Linder reports:

LINDER: Mike Strizki's been tinkering with cars his whole life. Over time the 49-year-old engineer became convinced that hydrogen fuel cell vehicles were the future of the auto industry. But during his 16 years with the New Jersey Department of Transportation, Strizki saw there was a problem with fuel cell cars: nobody was really building them.

STRIZKI: "You had the auto makers and you had government pointing fingers. Well, you know, you build the fuel cell cars first and then we'll provide the infrastructure. And they said, well you provide the infrastructure, and we'll build the fuel cell cars. And I got tired of hearing that argument. And I said well, one way to solve the problem is to make your infrastructure your home."

LINDER: Five years and half a million dollars later, Strizki's achieved his dream.

Here's how it works. Strizki's garage roof is covered with solar panels. They provide electricity for his house, and when there's extra power, it's routed to a device called an electrolyzer, which breaks down water into hydrogen and oxygen.

During the summer, the hydrogen is stored in fuel tanks on Strizki's property. And in the winter, he runs the hydrogen through a six kilowatt fuel cell to make energy. Strizki, his wife, and three children, are the first family in the country to live in a house powered entirely by hydrogen fuel cells and solar power.

And there's another benefit: Strizki can fuel up his hydrogen fuel cell vehicles at a gas pump near his garage.

STRIZKI: "The fuel cells have enough to run the vehicle at about 50 mph [80 kilometers per hour] on fuel cells alone. If you're going faster than that you're sipping off the battery pack at a very low rate."

LINDER: Strizki helped design this car for Rutgers University seven years ago. It's been running ever since. Now that he has a fueling station at his home, he plans to convert his other car, a Toyota Prius, to run on hydrogen as well.

Strizki pulls up to the hydrogen fueling station — a series of converted propane tanks out by his garage. Opening his car's trunk, Strizki connects a hose from those tanks to a smaller tank in the car.

STRIZKI: "That's how it refuels."

LINDER: Strizki's system runs like a well-oiled machine, only without the oil. But it wasn't always so simple. When he first decided to build his home power plant, Strizki sought government approval from his hometown of East Amwell, New Jersey.

STRIZKI: "I said all right, I'm doing this like anybody else who's getting a building permit. I walked into the town and I said here, I want to build a solar hydrogen fuel cell home ... and well, that ... you know, the first place I went was the zoning officer, and he told me it's an uncustomary use in a residential zone, and it'll be a cold day in hell before I allow this."

LINDER: East Amwell Mayor Kurt Hoffman says the zoning officer was known as a stickler. The township had accidentally removed a line in a local zoning law allowing homeowners to use alternative energy.

HOFFMAN: "So we did an addendum to the zoning ordinance to allow alternative energy usages. These kinds of things, they have to be publicly noticed, you have to have public hearings. That brought out some people's concern about hydrogen technology and the safety issue."

LINDER: Hoffman says Strizki brought in a series of experts to testify that his house wasn't going to blow up. The hydrogen was being stored at a safe pressure in the same type of tank normally used for propane.

Strizki says he'll probably never make back the half-million dollars it costs to build his system. But he hopes to cut the costs by 90 percent, by mass-producing and selling solar-hydrogen fuel cell systems to other homeowners. He says the future of the planet depends on renewable energy and not fossil fuels that have to be transported halfway across the world.

STRIZKI: "At least the fact that I'm using the energy in the same place that I've created it, the energy is still zero carbon, and it's still free, once you've paid for the equipment.

LINDER: The Strizki's don't skimp on electricity. They have a big screen TV, a hot tub, and all modern appliances. And Strizki takes great pride in the fact that he can power everything, including his car, using renewable hydrogen power.

STRIZKI: "There's no shelf life, and that's what powers the sun. When the sun stops shining, we're all dead. So this is a much better solution than digging big holes in the ground, throwing sulfur up into the air. This is something that's definitely sustainable. We just have to have the will to do it."

LINDER: For the Environment Report, I'm Brad Linder.

The Environment Report is a production of Michigan Radio. Support comes from the DTE Energy Foundation, and the Great Lakes Fishery Trust. You can find more information and subscribe to weekly podcasts at environment-report dot org.

MUSIC: "Our World" theme

That's our show for this week. 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.