MUSIC: "Our World" theme
This week on "Our World" ... The link between HIV/AIDS and domestic violence ... New technologies to brighten prospects for solar power ... and the trouble facing amphibians
WAKE: "Declines in mountain yellow-legged frogs are between 92 and 98 percent. And these are frogs that live in some of the most highly protected environments on earth."
Our website of the week will help you keep track, plus a setback for the U.S. space program, and more. I'm Art Chimes. Welcome to VOA's science and technology magazine, "Our World."
Avian flu deaths alarm Indonesian health officials
According to a new study, one third of the bird flu cases around the world are in Indonesia, where more than 80 percent of those infected die of the disease. Researchers publishing their findings this week in the journal The Lancet found early treatment appears to be the key to saving lives. VOA's Jessica Berman reports.
BERMAN: Between June 2005 and February 2008, there were 127 confirmed cases of avian influenza in Indonesia, or one-third of the number of cases worldwide.
Of these, 103 patients, or 81 percent, died as a result of the highly aggressive H5N1 virus, giving Indonesia the unfortunate distinction of being the hardest hit by the disease.
The extremely high mortality rate from the virus is cause for alarm among Indonesian health officials, who looked at why some people managed to survive.
Co-author of the Lancet study Nyoman Kandun says the timing of treatment appears to have made a difference.
Kandun says it appears patients who died did not receive prompt treatment because the early signs of H5N1 infection are mild, like a cough, runny nose, and sneezing.
But that is exactly the time when researchers found that patients infected with bird flu should begin receiving anti-viral medication.
KANDUN: "In our study, we found that starting treatment within two days was associated with significantly lower mortality than was starting treatment at this five and six day order. On average, most of the cases, admitted to hospitals (were) five to six days."
Researchers also found more than 70 percent of patients infected with the deadly flu strain had been exposed to sick or dead birds either directly or within their environments, such as in backyard farms or in markets.
Kandun says officials are now telling doctors and other public health care workers in Indonesia to inform patients about the possibility of bird flu so they can receive prompt treatment. Jessica Berman, VOA News, Washington.
Study in India links HIV infections, domestic violence
In too many parts of the world, women suffer frequent physical and emotional violence — inflicted by their husbands. For some time, researchers have believed that these women also find themselves at greater risk for contracting HIV because they have little power or influence in their marriages. As we hear from health reporter Rose Hoban, a new study in India offers more evidence that battered women are uniquely susceptible:
HOBAN: In too many parts of the world, women suffer frequent physical and emotional violence by their husbands. For some time, researchers have believed that these women also find themselves at greater risk for contracting HIV because they have little power or influence in their marriages.
Harvard researcher Jay Silverman says these women end up at higher risk for the AIDS virus because of their husbands' behavior outside the relationship.
SILVERMAN: "Men who are abusive have been found to behave differently outside of relationships. So they're not just abusive within the relationship, they're actually out there having much more extramarital sexual partners, to be more likely to be going to prostitutes or commercial sex workers, and then to be behaving particularly risky in those extra-relationship behaviors, to be having sex without condoms, that put them at particularly high risk of getting infected."
HOBAN: Now Silverman says he and colleagues in India have collected the strongest data to date to confirm this observation. He worked with the Indian government on a large survey, questioning more than 28,000 women about sexual violence. They also tested these women for HIV.
SILVERMAN: "We found that the women who experienced both physical and sexual violence from their husbands were about four times more likely than women who weren't abused, to be infected with HIV. And that was after taking into account all sorts of demographic, economic measures that might also account for those relationships."
HOBAN: Silverman says about one in three women in India report being abused by their husbands. This means potentially millions of women are at risk for contracting HIV. So, he says people working to prevent HIV need to confront a major risk factor: a cultural attitude toward women that condones abusive behavior towards them.
SILVERMAN: "And that's the sense of masculinity, a gender-based entitlement to control and abuse women and girls."
HOBAN: But Silverman says many, if not most HIV prevention strategies don't address these issues. And until they do, he says the world will continue to see HIV becoming a problem that affects women more and more.
Silverman's research is published in JAMA, the journal of the American Medical Association. I'm Rose Hoban.
Shuttle replacement delayed to 2014 at earliest
The U.S. space agency NASA this week put to rest any hopeful speculation that the replacement for the aging space shuttle would be ready earlier than planned.
The shuttle program is due to end after 10 more missions over the next two years.
The official target for the Constellation program's first human flight is 2015, but NASA confirmed on Monday its own internal target has slipped from 2013 to 2014.
With the space shuttle scheduled to retire in 2010, that leaves the United States without any way of its own to send astronauts into space for at least four years.
Jeff Hanley, manager of the next-generation Constellation program, told reporters in a telephone briefing that he now expects the first manned flight in the new spacecraft in September 2014
HANLEY: "We had a more aggressive target, the September 2013 target, that we set many, many months ago when our total plan and our total understanding was a lot less mature. So this is the product of going through this process of deciding what our requirements are, getting our contracts in place, understanding what the true costs really look like they're going to be."
The modular Constellation system includes a crew capsule, two sizes of rockets, and a lunar lander for an eventual trip back to the Moon.
But until Constellation is ready, and once the old shuttle fleet is grounded, the only American access to the International Space Station will be on Russia's Soyuz spacecraft.
Many amphibians threatened with extinction
This week, the Proceedings of the National Academy of Sciences published a collection of 18 papers examining threats to global biodiversity and wondering if we aren't entering another period of mass extinctions.
In one field, the answer may be yes.
Prof. David Wake of the University of California contributed a paper that describes a worrying decline in amphibian species — mostly frogs and toads — for almost two decades now.
WAKE: "At a minimum, one-third of the amphibian species in the world are threatened with extinction at the moment. Others are reduced to just tiny just fragments of their total range. In this paper we reviewed information for the mountain yellow-legged frogs of California, and we show that declines in mountain yellow-legged frogs are between 92 and 98 percent. And these are frogs that live in some of the most highly protected environments on earth."
Those frogs live in national parks; imagine the challenges amphibians have to face in less-protected areas.
Experts who have been following the decline in amphibian populations have got a pretty good idea of why frogs are dying, included loss of habitat and invasive species, but also infectious diseases, notably a virulent fungal infection.
Well, you can learn more about amphibians and the threats they face on our Website of the Week, which is our showcase for interesting and innovative online destinations.
WAKE: "AmphibiaWeb is a website that was motivated by the current decline in amphibians around the world. What we want to do is provide general biology about of the species, maps of their distributions, photographs, etc. We wanted to simply make a one-stop shopping place for all information about amphibians, and to do it all free of charge."
David Wake is director of the site, AmphibiaWeb.org. It includes an extensive database of very detailed information about more than 6,000 species of frogs, salamanders, and others. There's technical information for biologists and other specialists, but if you're just curious you can browse by country, to learn about your native amphibians, including many delightful pictures showing them in their natural habitat.
WAKE: "The photos are something that we're specially proud of, and that's something that's used very heavily. We have at present time 12,717 photographs, and that is one of the most popular features of the AmphibiaWeb site."
There are also audio recordings, such as this one of Bufo Maculatus, also known as the flat-backed toad, which is found throughout central and southern Africa.
All amphibians, all the time, at AmphibiaWeb.org, or get the link to this and more than 200 other Websites of the Week from our site, voanews.com/ourworld.
MUSIC: Rob Fisher and the Coffee Club Orchestra — "Doin' the Frog"
You're listening to VOA's science and technology magazine, Our World. I'm Art Chimes in Washington.
Safeguarding websites and digitizing books
The world is so complex today that sometimes solving one problem only creates another.
Well now, a scientist at Carnegie-Mellon University in Pennsylvania has come up with one solution to a couple of seemingly unrelated problems.
One is that when old books are being scanned and digitized, the software has a hard time identifying some hard-to-read words.
A second problem is that some websites want to be sure that they are interacting with a person, not a computer. A site that gives out free email accounts wants to avoid giving millions of free email addresses that would only be used for spam. One way they do this is with something called a CAPTCHA.
(CAPTCHA, incidentally, stands for "Completely Automated Public Turing test to tell Computers and Humans Apart." British mathematician Alan Turing, who in 1950 first proposed a test for non-human intelligence, said that if a machine is intelligent, you shouldn't be able to tell whether you're interacting with a machine or another person.)
A CAPTCHA is a small picture of distorted letters and numbers. They're hard for computers to recognize, but people are pretty good at it. You type in the characters, and you get your free email account. It only takes a few seconds. But:
VON AHN: "If you add it all up, it's about 200 million CAPTCHAs are typed every day by people around the world. Each time you type a CAPTCHA, essentially you waste 10 seconds of your time. So you know, if you multiply 10 seconds by 200 million, you get that humanity as a whole is wasting about 500,000 hours every day, typing these annoying CAPTCHAs."
Luis von Ahn helped devise the original idea for CAPTCHAs, so in a way he's responsible for all that wasted time. So writing this week in the online publication SciencExpress, he describes a different approach that harnesses all those wasted hours by making CAPTCHAs out of words scanned from old books.
He says CAPTCHAs work because humans are better than computers at some visual tasks, like recognizing some words printed in an old book.
VON AHN: "Computers cannot recognize them, but humans can. So what we're doing now is we're taking all the words that computers cannot recognize out of scanned books, and we're getting people to read them for us while they're typing CAPTCHAs on the Internet. So that's the idea of reCAPTCHA."
reCAPTCHA actually presents you with a pair of visually distorted words. One is already known, and if you get that one right, you're assumed to be human. The other word is one that can't be interpreted by the optical character recognition, or OCR software that turns the scanned pages of a book into computer text. When several users agree on what the word is, it's judged to be accurate. And accuracy is the name of the game. Von Ahn says reCAPTCHA achieves the same level of accuracy as human transcription services.
VON AHN: "And their accuracy guarantees are about 99 percent. So we've matched the guarantees of professional human transcribers."
So while keeping spammers and other bad guys out of websites, reCAPTCHA is adding value by improving the quality of digitized books.
VON AHN: "We've corrected about 1.4 billion words through reCAPTCHA. That's a lot."
Von Ahn says the popularity of reCAPTCHA continues to grow, and they are now transcribing the equivalent of about 160 books a day thanks to users like me and, maybe, you, too.
New technologies brighten chances for solar power
Increasing numbers of computers are just one reason why the demand for electric power keeps on going up. Most power around the world comes from burning fossil fuel, which generates greenhouse gases.
So the Energy Initiative at the Massachusetts Institute of Technology (MIT) is working to make solar energy an efficient and affordable power source. Two recent papers from the program published in the journal Science describe new technologies towards this goal. Eric Libby reports.
LIBBY: Plants have harvested the sun's energy for millions of years. For us, it is too costly and inefficient, compared to other fuel sources. Yet, two recent developments may change that.
Electrical engineer Mark Baldo at the MIT Energy Initiative and his colleagues have found a way to dramatically decrease the number of solar cells needed to absorb solar power. Cells are a costly component of solar energy systems.
BALDO: "We saw reductions on the order of about a factor of fifty. We think that when this is fully developed we will have reductions in the number of solar cells between a factor of 100 and a factor of 200."
LIBBY: Baldo has designed a system that channels the solar energy to specific areas on the panels where solar cells are located
BALDO: "It's like a piece of glass with a dye on top of it. Light comes in and it is absorbed by the paint and then it is reemitted but now it's reemitted so it is trapped within the glass. The light bounces in the glass until it gets to the edges. This concentrates the light at the edges of the glass pane. [And you can just put your solar cells there instead of over the whole surface of the piece of glass]."
LIBBY: More testing and development are needed to ensure that this system is marketable and can withstand long-term use. But Baldo says it shows promise in making solar energy systems more affordable.
His work complements the findings of his colleague Daniel Nocera, who solved the problem of how to get power from solar energy systems at night. Nocera's system can store energy during the day using a glass of water, a bit of electrical current, a metal electrode, and a simple catalyst of cobalt and phosphate.
NOCERA: "The catalyst takes the current then acts on water and splits it to hydrogen and oxygen. And hydrogen and oxygen are really good fuels-so when you recombine them you get an electrical current again."
LIBBY: This method has numerous advantages. Since it works at room temperature and consumes little electricity, it can function almost anywhere. Nocera says this finding means that solar panels, or photovoltaic cells, can be part of a home energy system.
NOCERA: "You can see that solar photovoltaics can become 24-7 because when the sun is shining you use the electricity directly, take some of that electricity while the sun is shining and feed it to the catalyst and then the catalyst breaks water to hydrogen and oxygen, you store it. The sun goes down."
LIBBY: At night, the hydrogen and oxygen are recombined into water, releasing the stored energy. The next day, the process repeats.
The work of both Baldo and Nocera pave the way for a future powered directly from the sun. This is Eric Libby in Washington.
And today we say goodbye and good luck to Eric Libby, who has spent the last couple of months with us here at the Voice of America as a Mass Media Fellow in a program sponsored by the American Association for the Advancement of Science. We'll miss his wry take on science news, his enthusiasm, particularly when microbes are involved, and his great sense of humor.
Counting the crane population in Vietnam
The dry season on the southwestern coast of Vietnam is crane-counting time. Near a small village on Vietnam's border with Cambodia, wildlife ecologists from the U.S.-based International Crane Foundation and researchers from Ho Chi Minh City stake out the ponds and marshes where the Eastern Saurus cranes gather to feed. Reporter Gil Halsted joined them, and learned that tracking the crane population in Vietnam and protecting the birds' habitat is a collaborative effort.
HALSTED: Just at dusk, a flock of cranes flies in from the east, calling to each other. The big birds' silhouettes are clear against a gray sky dominated by the belching smokestacks of a huge concrete factory.
The next morning, binoculars in hand, I join Tran Triet, the chief ecologist for the Crane Foundation projects in Vietnam. We scan the 2,000 hectares of uninterrupted green wetlands that makes up the International Crane Foundation's sanctuary. As the crane flies, it's about three kilometers from the pond where the flock roosts at night.
The raised dirt road we're standing on separates the sanctuary from a canal that runs along the border of the neighboring industrial shrimp farm.
As a motorboat buzzes by on the canal, Triet says the development pressures here are the same as they are near the concrete factory where the cranes roost.
TRIET: "Cranes will not come here if, y'know, too many people travel on this road and this canal. They will abandon this."
HALSTED: It's not just the boat traffic that threatens the cranes, says Triet. It's the shrimp farms themselves that are the greater threat. The brackish water in the ponds degrades the fresh water wetlands as the salt leeches into the soil. When the shrimp farms fail because of disease or drought, which they often do, Triet says the land is ruined for the cranes, as well as for rice cultivation. He says restoring it to wetland is almost impossible.
TRIET: "It will take a long time to actually wash away the salt. That will cost a lot of money. Not taking into account the chemistry of the wetland and the hydrology, it's maybe technically possible but very expensive, very complicated. If we fail, we [are] empty-handed."
HALSTED: That threat makes protecting the Foundation's wetland sanctuary even more crucial. This year's crane count found less than 200 birds feeding here, compared to more than 2,000 counted eight years ago.
In an effort to keep the population from shrinking more, Triet and his students set up a conservation project with the village of Phu My, close to the sanctuary. The villagers harvest lepironia from the wetlands. They use the plant's long grey-green stems to make mats for drying and winnowing their rice. Tran Triet says lepironia grows side by side with another species of grass that provides the main food source for the Eastern Saurus cranes.
TRIET: "So if we manage the harvesting of lepironia well, well then there will be no conflict of crane use of the same area."
HALSTED: Inside a small building with whitewashed walls about 20 women work at sewing machines and large looms strung with twisted strands of lepironia grass. They're weaving straw mats and tote bags to sell in handicraft shops in Europe and the United States. Their work for the Phu My Lepironia Grassland Conservation Project nets them almost two dollars a day. That's triple what they were making as rice farmers before the project began.
This marriage of interests — between cranes and the humans they share the land with — is the same approach the Crane Foundation uses in Wisconsin, where it's headquartered. Sitting in his office, wetland ecologist Jeb Barzen points to a map with potato fields marked on it and explains the strategy the foundation has used to convince farmers to use non-toxic pesticides and to preserve some of their land for cranes to feed on. In return, the farmers place a World Wildlife Fund label on their potatoes, which allows them to charge a premium for being environmentally friendly.
BARZEN: "It's trying to create an alternative to help compete within this economic system that we have that actually includes these environmental issues. So it's the same thing, but it's in a Wisconsin context."
HALSTED: The sand hill cranes in Wisconsin have an important cultural significance and a special place in people's imagination, just as the Saurus cranes do in Asia. Barzen says that's what makes it possible for this cooperative wildlife conservation model to protect both the Saurus cranes in Vietnam and the Sandhills in Wisconsin. For Our World, I'm Gil Halsted in Baraboo, Wisconsin.
That's our show for this week. If you'd like to get in touch, email us at firstname.lastname@example.org. Or use the postal address —
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Rob Sivak edited the show. 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.