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" ... Facing the possibility of a flu pandemic ... high-tech weather balloons ... And great new ideas for the world's poor...
GRANT: "With this technology the cost of the house is 40 percent cheaper just to build, and then the cost of the energy to heat the home is 75 percent cheaper."
Those stories, the challenge of teaching evolution, a Website of the Week for readers, and more. I'm Art Chimes. Welcome to VOA's science and technology magazine, "Our World."
There's new evidence that something out of today's headlines ? climate change ? may have been at work in the extinction of the woolly mammoth and other large mammals at the end of the last Ice Age. But as we hear from VOA's David McAlary, it is a controversial challenge to the traditional view that human hunters killed off the beasts.
McALARY: Scientists have long debated whether the cause was climate change or hunting by the human newcomers from Asia.
New scientific dating of 600 bones from that era from Alaska and Canada's Yukon Territory, including bones of humans, suggests that the warming climate was the culprit. University of Alaska scientist Dale Guthrie says it was a time when the landscape was changing from frigid grassland preferred by the large species to something less hospitable to them.
GUTHRIE: "What happened during this changeover time was that more moisture and warmer temperatures allowed trees and tundra to move in, a very unproductive landscape for large mammals but very dense greenery."
McALARY: The study of the bones' ages, published in the journal "Nature," shows that the woolly mammoth was already declining in number when humans arrived in North America from Siberia over the Bering Strait, which was still frozen at the time.
McALARY: But others cling to the belief that humans forced the large mammal disappearance ? not only in North America, but everywhere. University of Arizona geo-scientist Paul Martin has long described how the pattern of large animal extinctions coincides with human expansion and big-game hunting technologies.
MARTIN: "The arrival of the first people into a landmass [has] everything to do with the extinction of large animals at that time in that landmass."
McALARY: Supporting this view is the dating of several burial sites of big Australian land mammals, reptiles, and birds in 2002. It revealed that the animals died off about 46,000 years ago, a few thousand years after humans arrived. That was far earlier than the North American extinctions. University of Melbourne researcher Richard Roberts says climate change cannot be the explanation for the loss of this so-called megafauna. If it were, extinctions would have occurred simultaneously everywhere.
At the University of Alaska, Dale Guthrie agrees that animals are vulnerable to human colonization.
GUTHRIE: "The story is more complex than any simplistic idea. So to have one simple solution to all of extinctions seems to be rather unwise."
McALARY: David McAlary, VOA News, Washington.
Public health officials across the globe want answers to the same urgent question: What will they do if the deadly H5N1 avian flu virus mutates and sparks a human pandemic? Since 2003, about 100 people have died as the virus has spread out from East Asia. Millions of birds have also died from the disease or have been slaughtered as a precaution against further spread of the virus.
VOA's Rosanne Skirble has this report on the latest computer-aided strategies to slow the spread of a possible human pandemic.
SKIRBLE: Researchers at Johns Hopkins University developed computer models to analyze a variety of public health emergency scenarios, including restrictions on travel, isolation of infected patients, stockpiling of antivirals and the use of less effective but more available generic vaccines.
The model simulated the spread of a pandemic across the United States and England using data based on population density, demographics and human travel patterns.
Researcher Derek Cummings says the model shows that no single response can control a pandemic, should one develop.
CUMMINGS: "We found that you really need suites of interventions in order to significantly alter the course of the pandemic."
SKIRBLE: The models predict that an avian flu pandemic would peak about 60 to 80 days after the first case was reported. So closing off borders and restricting travel would only slow down the spread of the flu by a few weeks, Cummings says. He adds, however, that an approach that includes antiviral use for infected and non-infected individuals living in the same household, combined with school closures, could lower infection rates by more than 50 percent.
CUMMINGS: "In order to employ the antiviral strategies that we found most effective, you would need antivirals for fifty percent of the population. And thus far, the United States and the U.K. have targeted 25 percent of the population."
SKIRBLE: No specifically targeted vaccines are yet available for H5N1. But there are plenty of vaccines developed for other similar strains of avian flu. Cummings says they could help reduce the impact of a pandemic ? though only in combination with other responses. He says the most effective strategy is to stop the pandemic in its tracks, at its source.
CUMMINGS: "Even though it is a challenging task, given that this could emerge in any of a number of locations that might have very poor surveillance systems and very poor public health systems, I think that both the U.S. and the WHO [World Health Organization] have recognized that we should support nations across the world in shoring up the surveillance and getting ready to mount a response if there is an emergence [of the virus]."
SKIRBLE: Should a pandemic emerge, the models suggest the public health scenario could be grim. The sick would swamp the hospitals, millions would die and basic social services would be interrupted.
Anthony Fauci with the National Institutes of Health says preparing for the worst makes sense.
FAUCI: "And that doesn't mean to panic. That doesn't mean to think that the world is coming to an end. That means to pay attention to what is going on and to prepare ourselves."
SKIRBLE: Derek Cummings from Johns Hopkins University says the simulated epidemic models he and his colleagues have developed can help nations better assess their risks and direct scarce public health resources where they are needed the most.
The project is a joint effort by Johns Hopkins University's Bloomberg School of Public Health, the Imperial College, London, and RTI International in North Carolina. The research was published in the Journal Nature. I'm Rosanne Skirble.
Time again for our Website of the Week, and this time it's an online destination for those who love books and have lots of 'em.
SPALDING: "Library Thing is a website where you can catalog your books, and then when you've cataloged your books, your books connect you to other people. So you can find out the person whose library is just like yours. So it's a whole social system built around libraries and around cataloging of books."
Tim Spalding is the creator of LibraryThing.com, which, in a way, is really two websites in one.
It merges data from bookstore and library databases to help you easily list the books in your own collection using common-sense labels called tags - like "Egypt" or "historical fiction" - instead of complex library catalog categories.
LibraryThing also falls into a category known as social networking or social websites, which harness the power of the web to forge links between individuals. Friendster and MySpace are popular social sites, popular mostly with students and young adults. LibraryThing tends to attract a different crowd.
SPALDING: "LibraryThing tilts a lot older. There certainly are many teenagers and 20-somethings, but there's also people on there connecting with other people in their 40s and 50s and 60s. I think that's one of the things that makes it different from other social sites."
When I visit someone, especially for the first time, I'm always curious to find out what's on their bookshelves. Where I think LibraryThing gets interesting is in the ability to search and connect with other users based on what's in their libraries.
SPALDING: "Looking at someone's collection that's like yours is much more rewarding than just looking at a list of suggested books from someone you don't know or you don't have any reason to believe that they know anything. But if you read a review of someone who likes and has 50 of your books, then you know that there's a common ground of taste there."
So far, about 30-thousand users have signed up, and they have cataloged a total of some two and a half million books.
This is actually a site that's easier to understand if you take a look. Check it out at LibraryThing.com, or get the link from our site, voanews.com/ourworld.
MUSIC: Jim Salestrom - "The Library Song"
You're listening to VOA's science and technology magazine, Our World. I'm Art Chimes in Washington.
We are overdue to dip into the Our World mailbag to answer a listener's letter. Mr. Muhammad Shamim of Kerala state in India wrote us recently wanting to know, what is a radiosonde?
To find out, I spoke with T.N. Krishnamurti, a professor of meteorology at Florida State University in Tallahassee. He explained that radiosondes are packages of instruments carried up into the atmosphere by helium-filled weather balloons.
KRISHNAMURTI: "There is temperature-measuring sensor, pressure-measuring sensor. It gives you the altitude of the balloon as it goes up, and they carry also the position because of the GPS ? global positioning system. Via satellite we can tell the precise location of this balloon as it drifts in the winds. It gives you the humidity. It also now gives you the wind speed and wind direction. And the radiosonde is a centerpiece of weather observations over the globe."
More than 6,000 weather stations around the world launch radiosonde-equipped balloons twice a day, and as the balloons carry the instrument package up as high as 30 kilometers, the information is radioed back to Earth to be fed into a global network that provides the information that helps your local forecaster predict tomorrow's weather.
Forecasters also use satellite data, of course, but both weather balloons and satellites each supply information that complement the other. In addition, Krishnamurti says data from radiosondes provides a "reality check" for satellite observations.
KRISHNAMURTI: "The radiosonde is a better tool for giving you those numbers than any satellites, because the remote [satellite] sensing is still not that accurate. It has to be calibrated against the radiosondes, so these 6,000 sites help calibrate the entire satellite database."
Maybe someday satellites will provide all the information needed for weather forecasting, but for now radiosondes are a vital part of the data collection process.
We hope that answers Muhammad Shamim's question about radiosondes. We're sending him a special VOA gift as our way of saying thanks. If you've got a science question, email it to firstname.lastname@example.org, or listen for our postal address at the end of the show.
In classrooms across the United States, science teachers are increasingly finding themselves on the front lines of a decades-old battle of ideas, pitting the scientific theory of evolution against the Bible. So when some 15,000 science teachers convened for their annual conference recently, many attended workshops designed to help them deal with the issue. Gloria Hillard reports from the 54th Annual Science Teachers Convention in California.
HILLARD: Amid all the lab gear and panel discussions at last month's annual national science teachers' conference, one of the largest draws was a book signing.
MILLER: "Melissa-? M-E-L-I-S-S-A, right?"
TEXT: Brown University Professor Ken Miller is signing copies of the biology textbook he wrote with co-author Joe Levine. Known as the "dragonfly book" from its iridescent cover photo, it's a popular classroom text. It was also the book at the center of the most recent evolution-versus-intelligent design landmark trial in Dover, a small Pennsylvania town, where the school board questioned the teaching of evolution in the classroom.
MILLER: "Our book is the one that the Dover teachers chose and the board of education in Dover objected to because it had too much evolution in it."
HILLARD: "In the end, a federal judge ruled that "intelligent design" could not be taught in science classes. Intelligent design holds that natural processes alone can not explain the organization of life forms and the universe itself, and thus must be the work of an higher force. Advocates leave open the question of whether that force is God.
The Dover decision was a clear victory for Darwinism, but despite that legal precedent, Miller says the challenges to teaching evolution are ongoing"
MILLER: "I think this is an issue everywhere in the country."
HILLARD: And that's one reason science teachers from everywhere in the country were seeking answers to how to deal with the increasingly controversial issue.
GRADY: "That's usually the number one question students ask, What are you going to cover in evolution?"
HILLARD: Patrick Grady is a biology teacher in Orange County California, where there's a large conservative Christian population. Many of those parents start off teaching their children at home, then switch to public high schools, where the kids are exposed to new ideas that challenge what they learned at home and in church.
GRADY: "And as soon as you bring up the topic of evolution they want to put a barrier or wall and they don't want to listen.
HILLARD: Dozens of teachers wanted to listen to Ken Miller. It was standing room only at his workshop, "Darwin Denied: Teaching Evolution in a Climate of Controversy." Miller started with a brief history lesson and then set the stage for what they were up against today. Teachers took out their notebooks as he flashed popular anti-evolution websites on a large screen.
MILLER: "This is from the Answers in Genesis website. It is probably the best compendium of anti-evolution information and propaganda that you will find."
HILLARD: Miller also gave the teachers advice on how to respond to their students' questions, especially those that challenge the very basics of evolution, from human origins to missing link fossils. Although his was clearly a like-minded audience, at the end of the day one of the most important concepts biology textbook author Ken Miller wanted teachers to take home with them was to be respectful of the religious belief of students.
MILLER: :I think religion and science, properly understood, compliment each other by giving a complete world view, and if properly understood they ought not to be in conflict."
HILLARD: Evolution disturbs people, Miller says, because it concerns where we come from and who we are today, and he expects it to continue to be a contentious issue at the intersection of science, religion and politics. For Our World, I'm Gloria Hillard in Los Angeles.
In Washington this week the World Bank held its annual Development Marketplace, where teams of inventors and entrepreneurs showcased innovative solutions to problems in the fields of water, sanitation and energy.
A field of more than 2500 competitors was narrowed to just 118 finalists from 55 countries. At stake were World Bank grants for up to $200,000 to jump start their projects.
The spacious lobby of World Bank headquarters is crowded with booths where exhibitors are showing off their projects. Some are expensive-looking, professional jobs. Others show more enthusiasm than fancy graphics. But all feature ideas that, in some way, promise to change people's lives.
You've probably heard of solar heating and solar cooking. Carl Erickson wants to bring solar ice-making to Kenya. At present, many small dairy farmers lose much potential income to milk that has spoiled. To prevent that, they can boil the milk, but that robs it of taste and nutrients. Erickson's technology is based on ammonia absorption, a century-old refrigeration technique.
ERICKSON: "And if they had ice, they'll be able to chill these products so that they can have more time to market it to the urban areas, so that they'll be able to sell it. ... "
TEXT: A few steps away, another technology is on display, this one perhaps a little more familiar to many of you.
TEXT: If you happen to be listening to a Freeplay radio - the one that you crank up - you are actually listening to a cousin of this device, called Weza (WAY-zah). It's a small box that sits on the floor with a pedal that you pump with your foot.
PEARSON: "It's a portable energy source that offers reliable, dependable power anytime, anywhere, and it charges a wide range of communication and other low-energy devices such as cell phones, LED lights. It can even jump-start a motor car and pump a tire."
TEXT: Kristine Pearson of the Freeplay Foundation says the foot-powered generator can also be used to power medical devices, which could improve health care in rural areas. The Foundation will train and support 50 Weza "pioneers" in Rwanda, who will set up micro-businesses, essentially selling power to their neighbors.
Both the Weza generator and the solar powered icemaker were among the winners at this year's World Bank Development Marketplace, as was a proposal by Habitat for Humanity for affordable housing in Kyrgyzstan. They want to marry efficient, under-floor electric heating with a traditional but now abandoned construction technique using cane reeds as a sustainable source of insulation. Natalie Grant says some Kyrgyz families spend up to half their income on heating.
GRANT: "With this technology the cost of the house is 40 percent cheaper just to build, and then the cost of the energy to heat the home is 75 percent cheaper."
TEXT: In China, the plan is to use shellfish to purify polluted waters. The challenge, explains David Aldridge of Cambridge Environmental Consultants, is persuading local residents to leave the mussels in the water.
ALDRIDGE: "Now, one of our problems is that the Chinese, like many Americans, like to eat mussels. So what we need to do is to make the Chinese value our mussels more as alive than mussels on a dinner plate."
TEXT: His solution is to seed the mussels so they will produce pearls, creating a new industry that also cleans up the water.
ALDRIDGE: "So we have a commercial product that the Chinese communities can sell and therefore they propagate the mussels for us. They get money; we get clean water, and everybody wins."
TEXT: The Chinese partner in that proposal, the Kunming Institute of Zoology, couldn't be in Washington as their representative was not issued a visa.
Thirty of the projects won World Bank funding, including the ones we've mentioned so far. But even among the others, there was excitement and innovation.
World Bank President Paul Wolfowitz told the competitors that even those who didn't win funding had gained a lot.
WOLFOWITZ: "And I think, as I said yesterday, that everyone who's here is a winner. You were outstanding just to get here. And I hope, even if you don't leave here with an award, you'll leave here with a new network of contacts, with a new wealth of knowledge and ideas. And hopefully, the interactions that have taken place here between participants will generate even more innovative ideas. Thank you. (applause)."
TEXT: Details about all the finalist projects are online at developmentmarketplace-dot-org, or get the link from our site, voanews.com/ourworld.
MUSIC: "Our World" theme
That's our show for this week. If you want to get in touch, email us at email@example.com. Or use our postal address -
Voice of America
Washington, DC 20237 USA.
The show was edited by Rob Sivak. Eva Nenicka is our 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.