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Straight ahead on "Our World" ... A grand proposal to 'go solar' big-time by mid-century... alternative fuel vehicles at the Washington Auto Show ... and the potential danger of caffeine to the health of a fetus...
LI: "Generally they've very little ability to metabolize caffeine, so caffeine can have a much stronger pharmacological and toxicological effect."
Drinking coffee and the risk of miscarriage, 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 this week previewed two satellites it plans to launch later this year to study Earth and its environment.
June is the target launch date for the Ocean Surface Topography Mission, which will measure sea level. That's a key factor in global warming, since ocean water expands — rises — as temperatures go up. Earth Science Division director Michael Freilich told reporters the Ocean Surface Topography Mission, or OSTM, is the latest in a series of satellites providing this important data for climate scientists.
FREILICH: These satellite missions have provided clear and unambiguous evidence that sea level globally is rising, and we can see the trend. It's about 3.2 millimeters per year. It's these sorts of measurements that tell us where we are environmentally now and how the Earth's environment is evolving."
NASA's other Earth science satellite this year is the Orbiting Carbon Observatory, or OCO, will measure the best known greenhouse gas, carbon dioxide, in the atmosphere, charting daily, seasonal and regional variations. NASA Associate Administrator Alan Stern noted that rising carbon dioxide or CO2 levels in the atmosphere are known to play a key role in climate change.
STERN: "And yet we have not yet put into orbit a global system that can actually both monitor that rise in CO2, but also look at the individual sources and sinks — where on the planet is the CO2 being absorbed and where is it being emitted — so that we can better understand the physics behind the problem and not just think of the Earth as a single point source."
NASA Administrator Michael Griffin said these two science satellites, and the ones that will follow in years to come, continue the important job of providing information for the scientists studying earth and its environment.
GRIFFIN: "We wouldn't be able to have discussions on climate change if it wasn't for the data that NASA brings home to the science community to study and analyze."
NASA officials point out that many researchers combine data from different satellites, instruments flown on airplanes or weather balloons, and ground measurements, providing a more complete picture than you can get from any one platform.
The 2008 Washington Auto Show opened this week. They've got something for every auto enthusiast. But being as this is Washington, where Congress recently upgraded fuel economy standards for the first time in three decades, automakers also want to stress their commitment to reduced emissions and new technologies to replace century-old gasoline and diesel engines.
The magazine Green Car Journal used the occasion to announce the winner of its new Green Car Vision Award. Publisher Ron Cogan introduced the hydrogen-powered Chevrolet Equinox Fuel Cell.
COGAN: "It brings to the highway an efficient power plant that offers zero emissions, no CO2 greenhouse gases, and highly efficient conversion of its fuel to motive power. It feels familiar to drive, even as its power plant works in ways that are unfamiliar to most drivers."
The General Motors product, a modified version of a current sport-utility vehicle, beat out hybrid- and fuel cell-powered competitors from Toyota, Honda, BMW, and a battery-powered pickup truck from a new company called Phoenix Motorcars in California.
General Motors has built more than 100 Equinox Fuel Cell vehicles and they'll be test-driven for three months at a time by ordinary Americans. They'll provide feedback to help the company refine the design as GM develops this and other fuel cell models.
Mention alternative vehicles to most American motorists and they'll think about gas-electric hybrids, like the popular Toyota Prius. Some critics see hybrid vehicles as an interim technology that will be supplanted by hydrogen-powered fuel cells or battery-powered plug-in electric cars. But Toyota executive Tom Stricker suggests that some type of hybrid will be around for a long time.
STRICKER: "The way we view it, hybrids are not an interim step but an integral step. A hybrid is a system of electric motor, battery, regenerative braking, dual propulsion, electronic controls to do all that. And that system can be applied to any power train."
With hundreds of millions of cars and other vehicles on the road worldwide, there is not going to be an immediate shift away from traditional engines burning traditional fuels. We may be entering a period when different technologies share the road, like a century ago when gasoline, electricity and even steam were competing for dominance. Whether one technology will come to supplant the internal combustion engine down the road is anyone's guess.
Pregnancy can be an exciting, joyful time. But for an unknown percentage of mothers-to-be, their pregnancies end in a spontaneous loss of the fetus, commonly known as miscarriage. Doctors and researchers don't know what causes many miscarriages, but as we hear from health reporter Rose Hoban, one California researcher has identified a possible culprit.
HOBAN: Some previous research looked at the relationship between caffeine intake and miscarriage. But Dr. DeKun Li from the Kaiser Permanente health system in California says the results were unclear. So he took advantage of the Kaiser system's many patients to study the phenomenon. He recruited about a thousand women and asked them about their caffeine intake. Then, he divided them into three groups.
LI: "One is the women who said they never had any caffeine intake in pregnancy, and another group said they had the caffeine intake, but less than 200 mg per day, and then we have a third group which they said they had more than 200 mg a day of caffeine intake. Then we compare their miscarriage rate.
HOBAN: Li found that the women who had more than 200 milligrams of caffeine per day had more than double the rate of miscarriage compared to the women who drank no caffeine.
Li explains that caffeine could affect pregnancy in two ways.
LI: "One of them is that the caffeine can readily cross the placental barrier and directly affect the fetus. While the mother usually has a well-established metabolic system to metabolize caffeine, fetus usually doesn't. Their ability to metabolize caffeine varies, but generally they've very little ability to metabolize caffeine, so caffeine can have a much stronger pharmacological and toxicological effect."
HOBAN: Li also notes that a high concentration of caffeine can cause blood vessels to contract. He suggests this could reduce blood flow to the placenta and have a detrimental effect on a developing baby.
Li says it's easy to consume 200 milligrams of caffeine in a day — that's about what Americans get in two regular cups of coffee. And for his subjects, that was by far the most common source of caffeine.
LI: "And then the next source probably is tea, some tea, caffeinated tea, and some caffeinated soda."
HOBAN: Li says his study's results are quite clear and should lead to a recommendation that women limit their caffeine intake during pregnancy. His research is published online in the American Journal of Obstetrics and Gynecology. I'm Rose Hoban.
Three antiparasitic drugs may soon be dispensed simultaneously to people living in areas in Africa where parasitic worms are endemic. The results of a large study from Zanzibar show administering three drugs at the same time causes minimal side effects. Experts say the regimen, if adopted, would result in significant cost savings. VOA's Jessica Berman reports.
BERMAN: Experts say many people in Zanzibar and other parasite-endemic regions are usually infected with more than one type of worm.
Antiparasitic drugs are given each year to manage the worm infections. The drugs are not usually dispensed at the same time for all of the diseases. Public health officials say time and resources could be saved if all three drugs could be doled out simultaneously.
The study in Zanzibar, part of Tanzania, involved a three-drug regimen of Ivermectin, albendazole and praziquantel. The drugs are active against worms that cause elephantiasis and schistosomiasis and soil-worms or helminths.
The first phase of the study involved more than five thousand children. After finding no severe side effects to the triple therapy, investigators from Zanzibar and Tanzania — as well as from the School of Tropical Medicine in Liverpool, England — expanded the trial to treat Zanzibar's entire eligible population of 700,000 people.
Again, investigators found the side effects were minimal when the drugs were given together.
David Molyneux is with the Lymphatic Filariasis Center at the School of Tropical Medicine in Liverpool. He says that drug companies are donating two of the antiworm drugs — Ivermectin and albendazole.
Molyneux says a dose of the third drug, praziquantel, to treat schistosomiasis, costs 20 cents.
MOLYNEUX: "Basically what we are saying is that for 50 cents, probably — which would be 20 for the praziquantel, 30 cents for the delivery and the social mobilization — you could really make pretty big cost savings in delivery and treat the targeted populations across a much wider area of Africa."
BERMAN: Molyneux is co-author of the study on the triple drug regimen, which is published in an online journal of the Public Library of Science, PLoS Neglected Tropical Diseases.
Molyneux says further studies will be done to confirm the safety of the three-drug regimen, which could then be submitted to the World Health Organization for approval. 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 site at the intersection of science and blogging, where scientists can express their personal opinions — and don't have to be peer-reviewed.
BLY: "Scienceblogs.com is a conversation about science and a community of people who are passionate about science and its place in society."
Adam Bly is the founder of ScienceBlogs.com, where 67 writers have their say on a wide range of mostly science-related subjects.
BLY: "Ah, everything from the minutiae of squid and particle physics to sort-of big social issues of the fight between creationism and evolution, the place of science in policy making and global warming."
The breadth of subject matter can be, well, breathtaking, and the personality of the individual bloggers comes through in their writing, not to mention the quirky names they choose for their blogs. Chaotic Utopia is written by a Colorado student who recently posted about fractals. The highly respected Effect Measure blog keeps a skeptical eye on public health issues. Stranger Fruit is the work of a university biologist.
Traditionally, scientists have spoken through their work, which appears in scientific journals and can be pretty incomprehensible to non-scientists. Adam Bly says ScienceBlogs.com gives scientists a direct way of communicating with the rest of us.
BLY: "It really has become a new way for scientists to speak directly to the public. It's created a new soapbox for scientists to talk to the people who, by and large, are funding their research and who have a vested interest in the outcome and consequences and byproducts of scientific research."
We reached Adam Bly in Switzerland, where he's exploring the possibility of a German language version. Informed opinion on science and society at ScienceBlogs.com, or get the link from our site, voanews.com/ourworld.
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It's VOA's science and technology magazine, Our World. I'm Art Chimes in Washington.
The U.S. National Academy of Sciences is out this month with a new edition of a book on evolution aimed at the general public, not scientists. The book's aim, says Academy president Ralph Cicerone, is to provide a comprehensive and up-to-date picture of the current scientific understanding of evolution.
CICERONE: "... Because evolution is an important fact of nature. And it's also one of the bedrock theories in all of modern science."
The new book, called Science, Evolution, and Creationism, is squarely aimed at those groups in American society — primarily Christians who believe in a literal reading of the Biblical story of creation — who want, at the very least, to have that version taught alongside evolution. Prof. Gilbert Omenn of the University of Michigan Medical School was among the authors of the new book.
OMENN: "We are very keen that people understand the nature of science and of scientific inquiries, scientific method, which is not about accepting on faith a statement or a writing or a scriptural passage. So there is really not any place in the science classroom for creationism."
Bruce Alberts, editor of the journal Science, said science is key to America's prosperity, as evidenced by the country's advances in computer technology and biotech. But he warned of the consequences of failing to educate the population as a whole about scientific matters and ignoring what science knows.
ALBERTS: "We're going to make very bad decisions as a nation, policy decisions, about our future, whether it's about how much arsenic in drinking water we should allow, or what we should do about energy policy in view of the great threat of global warming."
The new book, Science, Evolution, and Creationism, is available as a free download from the National Academies' website at nap.edu.
Finally today, this month's issue of the venerable magazine Scientific American includes a 3,500-word article setting out what they call a Solar Grand Plan, proposing a massive shift away from coal-burning power plants for electricity production over the next 40 years. The article describes giant arrays of solar power collectors in the sunny American Southwest, a way of storing power for nights and cloudy days that doesn't require batteries, and a new national transmission grid to deliver electricity to consumers. The authors say two-thirds of U.S. electric needs could be met by clean solar power by mid-century.
To find out more, I spoke with co-author Vasilis Fthenakis, a photovoltaic scientist at Brookhaven National Laboratory, who also teaches at Columbia University.
FTHENAKIS: "We think we should recognize the big potential of solar energy, and the fact that solar energy is the only big player out there, is the only technology that could satisfy all the energy needs of the United States among renewables."
Q: So in your Grand Plan you would cover about 120,000 square kilometers in the American Southwest, and you'd cover it with two different kinds of solar power collection. Can you describe them, and why do we need both?
FTHENAKIS: "The two are photovoltaics, solar electric systems that convert directly photon energy to electricity, and concentrated solar power systems. They go over a conversion to thermal energy before they produce electricity in a thermo-electric cycle, the same type of cycle that we have currently in the conventional power plants. We suggest to use both because the verdict is still out of which of the two can do it most cost-effectively.
"There is also the issue of intermittency. In the short term, like when we have clouds or perhaps going all the way from a sunny day to night hours, the concentrated solar power CSPs can do it. So they can provide a few hours of storage, up to perhaps 16 or perhaps 24 hours of storage. But with current technology they cannot go to several days of storage.
"Photovoltaics by themselves do not provide any storage but coupled with compressed air energy storage, they can give us electricity for several days or weeks in series.
"So the two complement each other, and they're both evolving. And we don't know yet which of the two can be more cost-effective to do the job."
Q: You mentioned the compressed air storage, and this was something that was quite surprising to me because I think most folks, when they hear about solar power and consider the question of, as you put it, intermittency, the fact that the sun doesn't shine all the time, would normally think about storing electricity the way we normally store electricity, which is in batteries. But your conclusion is that's probably not the most efficient way to do it.
FTHENAKIS: "It is very expensive. With the current battery technologies, we still have a differential of about a factor of two, 2.5 between the cost of storing electricity, in relatively large scales, between compressed air energy storage and batteries. So compressed air energy storage is a lot cheaper."
Q: And just briefly, how would the compressed air storage work?
FTHENAKIS: "We use excess electricity to compress air, and then we release air from the compressed air in the storage through gas turbines and produce electricity through generators."
Q: Does your Grand Plan require brand new technologies, or does it require incremental improvements in existing technologies?
FTHENAKIS: "It does not require any new technologies. But if new technologies are developed, the plan would be easier to be accomplished. On transmission, for example, if we have superconducting materials, then transmission will be easier. We'll have fewer lines, we'll have larger capacities. But we show that even with existing technologies with well-forecasted improvements, we can do the job, that solar has enough technical and geographical and economical potential to satisfy all the energy needs of the United States if we elect to [go] that way."
Q: Let me take you just a little bit beyond the boundaries of your paper, if I may. The United States is a big consumer of fossil fuels, but we represent only a fraction of the global consumption. Could your Grand Plan, which is set out for the United States, be perhaps a model for use elsewhere as well?
FTHENAKIS: "I believe that it can, but with perhaps different variations of it. One of the big promises of solar energy as we understand is to provide electricity to these billions of people — at least 1.5 billion in Asia and Africa — that don't have electricity. And there is a lot of hydro[electric] production, potential production in the west and central Africa, and we would be looking to couple this, perhaps, with solar from northern Africa. So I believe that there is a mixture of renewable energy that could satisfy the needs of many countries. It doesn't have to be mostly solar, as here. There are different mixtures that are applicable to different countries, different regions."
We reached Vasilis Fthenakis at Brookhaven National Laboratory. His article in Scientific American says the Solar Grand Plan would require more than $400 billion in government subsidies. But the payback would include dramatic reductions in greenhouse gas emissions, as well as reduced trade deficits and geopolitical tensions by virtually eliminating the need for oil imports.
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That's our show for this week. If you'd like to comment on our show, or if you have a science question that we might answer on the air, email us at firstname.lastname@example.org. Or use the postal address —
Voice of America
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Rob Sivak edited the program. Eva Nenicka 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.