Straight ahead on "Our World" ... Potential new ways of attacking the virus that causes AIDS ... the benefits of making ethanol from switchgrass ... and a surprising discovery on the East African savannah:

PALMER: "My intuition was that if you remove something that feeds on a tree, you'd expect the tree to start to flourish and do well, and what I was seeing was sort of the exact opposite of that."

A strange symbiosis, the Consumer Electronics Show, and more. I'm Art Chimes. Welcome to VOA's science and technology magazine, "Our World."


In what is being hailed as a major step in the fight against HIV/AIDS, U.S. researchers have identified 273 proteins that are key to reproduction of the virus that causes AIDS. That gives scientists many potential new targets for drugs to disrupt the sophisticated life cycle of the virus.

ELLEDGE: "The set of proteins will provide a lot of insight into how the virus actually functions. And people may be able to use that information to somehowrcumvent the virus. But the other way you can look at it is that now there are more targets. They're potential targets."

Stephen Elledge of Harvard Medical School is the lead author of the paper describing the discovery, which was published Thursday online in SciencExpress.

HIV has little genetic material of its own, so when it infects a cell, it hijacks the cell's genetic code to reproduce. This new study identifies some of the cell proteins the virus uses in that process.

Speaking in a Science magazine podcast, Elledge said current anti-AIDS drugs generally focus on the virus itself.

ELLEDGE: "But the problem is that HIV is a highly mutable virus, so it can change the target of the drug so that it no longer binds the drug that well."

Which is why Elledge focused on human proteins. Of the 273 he identified as being essential to HIV reproduction, only 36 were previously known.

Leading AIDS researchers hailed Elledge's work. HIV co-discoverer Robert Gallo called it "terrific." Dr. Anthony Fauci, head of the U.S. National Institute of Allergy and Infectious Diseases described it as "elegant science," but he told The New York Times that it's too soon to tell if this laboratory discovery will actually prove useful in treating patients.

Elledge also admits there could be side effects to any treatments developed using his discovery.

ELLEDGE:  "And the downside, the potential downside, is that if the organism -? us ? needs that particular protein, [then] if you inhibit it, you might get sick. And of course, that's true for any drug. If anyone finds a drug target and they decide they're going to make a drug that inhibits it, it has to be tested in people to see how people tolerate having that pathway reduced."

To find the 273 proteins that are part of the HIV life cycle, Elledge and his colleagues screened thousands of possibilities using a technique honored with a Nobel Prize a year ago, RNA interference, which can be used to effectively shut down one gene at a time within a cell. Then the researchers infected the cell with HIV to see if the virus could reproduce.

ELLEDGE:  "And we did this for over 20,000 human proteins, all the known, currently known proteins. We wanted to cover everything, we wanted to leave no stone unturned to see what the list looked like. And that's how we did it."

Stephen Elledge, of Harvard Medical School and the Howard Hughes Medical Institute, says the same approach could be used to help find targets in the fight against other virus infections as well.


Researchers at the Massachusetts Institute of Technology have identified a critical difference between the flu viruses that infect birds and those that infect humans. As VOA's Rosanne Skirble reports, the discovery could help scientists monitor the evolution of avian flu strains and speed the development of a vaccine against a deadly flu pandemic.


Researchers at the Massachusetts Institute of Technology have identified a critical difference between the flu viruses that infect birds and those that infect humans. As VOA's Rosanne Skirble reports, the discovery could help scientists monitor the evolution of avian flu strains and speed the development of a vaccine against a deadly flu pandemic.

SKIRBLE: Influenza is a seasonal virus. What has public health officials worried is the highly pathogenic H5N1 bird flu that's necessitated the destruction of millions of poultry worldwide and caused 212 human deaths since it first appeared in Hong Kong in 1997.

Scientists say it is highly likely that the virus could mutate and spread from person to person, leading to a pandemic that could rival the 1918 Spanish Flu that killed 50 million people.

Massachusetts Institute of Technology bio-engineering professor Ram Sasisekharan has been studying the differences and similarities between avian and human forms of influenza virus. Sasisekharan says sugar is key to how the virus works.

SASISEKHARAN: "Virtually every cell line in our human body, and particularly the ones that line the upper airwaves have a coat of sugar on them. The sugar plays a central role in the ability of the virus to recognize human tissues or human cells as an important step leading to infection eventually."

SKIRBLE: The protein on the surface of the virus latches on to the sugar or glycan receptors and gains entry into the cell. The virus then replicates itself and spreads infection from the inside out.

What Sasisekharan and colleagues report this week in the Journal Nature Biotechnology is that bird- and human-cell sugars have significantly different shapes.

SASISEKHARAN: "The avian viruses bind to sugar shapes that typically take a structure that resembles a cone, while the human adapted viruses appear to recognize sugar shapes that resemble that of an umbrella."

SKIRBLE: Computer modeling and three-dimensional images revealed more detail. Sasisekharan says seasonal human flu viruses bind to this umbrella shape, but not to the H5N1 bird flu strain that health officials fear.

SASISEKHARAN: "What this enables us to do is to systematically look at the evolving H5N1 strains to see if these viruses are beginning to achieve some sort of specificity or recognition to the umbrella-shaped glycans [sugars] that are there in the upper airways."

Sasisekharan says that can help researchers develop drugs or vaccines that could block the H5N1 virus.

SASISEKHARAN: "By designing molecules that could mimic the umbrella-shaped structures so that these molecules could potentially act as decoys to trick the virus from binding to the umbrella-shaped structures that are there in the upper airways [respiratory system]."

SKIRBLE: Sasisekharan says the findings could also speed development of more effective strategies to combat seasonal flu, which kills 36,000 people in the United States alone each year.


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

This time we consider the dark side of computing, where evil programmers are writing key loggers, virus programs, trojan horses and other nasty kinds of software ... and showcase the good guys who are trying to stop them.

WEINSTEIN: " is a partnership between top academic institutions, technology industry leaders, and volunteers, committed to protecting Internet users from threats to their privacy and security caused by bad software."

Maxim Weinstein is manager of, at Harvard University's Berkman Center for Internet and Society.

The term "badware" refers to software that can cripple your computer, take it over and turn it into a spam-sending robot, or steal your personal identity or financial information. Some badware can be installed without your knowing it. Others are hidden inside fun or useful applications, such as instant messaging programs.

Badware, or malware as it's also called, can get onto your computer through email or an unsecured Internet connection, but often it's distributed through websites.

No website is completely immune from badware, but Weinstein says some kinds of sites are more likely to pose a danger.

WEINSTEIN: "That would be sites involving pornography, illegal copies of software, criminal behavior ? they tend to be a natural target for these types of attack." can help you learn about websites that might be a source of nasty software, but how do you know if you've been victimized? Weinstein says there are some signs to watch for.

WEINSTEIN: "Sudden changes in the performance of a computer, when your computer yesterday was working fine [and] today it's suddenly slower, suddenly you're getting pop-ups that weren't showing up before, even when you're not online. Those are the first tip-offs. Of course, the most important message we always have for people is, prevention is far easier than detection and removal."

To help avoid websites that might put those sorts of programs on your computer, has a clearinghouse of sites that have been linked to badware. If you have your own website, it's a good place to check to see if your site has been hacked and may be inadvertently distributing badware.

Check it out at, or get the link from our site,

MUSIC: Holmes Bros. ? Bad Moon Rising

No badware here at VOA's science and technology magazine, Our World. I'm Art Chimes in Washington.


Last week on Our World we reported on a study about the environmental impacts of producing biofuels, such as ethanol from corn or sugar cane.

This week, we continue the theme with a new study on the energy efficiency of biofuels.

The study, by a U.S. Department of Agriculture scientist, comes amid ongoing controversy over ethanol produced from corn, in a process that is heavily subsidized in the United States, and which some critics say is inefficient.

Researcher Ken Vogel investigated how much energy it takes to produce ethanol from a hardy American plant called switchgrass by considering all the energy that goes into the production process. The equation included the energy needed to power tractors, manufacture fertilizer ? everything involved in commercial agriculture. Vogel and his colleagues concluded that switchgrass can be an efficient source of ethanol.

VOGEL: "It's a baseline study, and what it shows is that perennial bioenergy crops, such as switchgrass, have potential for high net energy yields."

Q: When you say high, can you quantify that a little better?

VOGEL: "Well, there's approximately five times as much energy produced as used in the production."

That's about four times more efficient than when ethanol is made from corn.

Making ethanol from corn is an established technology, but Ken Vogel says, manufacturing ethanol from a woody plant like switchgrass is still some years away.

VOGEL: "The Department of Energy awarded grants to six companies to co-fund six biorefineries, and I think these will be completed around 2010. And so this will be the first large-scale test of this cellulosic technology. And so it's a technology that's still under development, where the corn-ethanol technology is really mature and it's working."

In addition to being more efficient, according to Vogel's study, making ethanol from switchgrass doesn't use a crop, like corn, which would otherwise be used for food or animal feed. The demand from even relatively modest ethanol production from corn in the United States has started to push up corn prices.

Voge's research was published this week in the Proceedings of the National Academy of Sciences.


Our intestines are packed with bacteria that help us digest our food. In exchange, we provide them a place to live and something to eat.

Biolgists call this sort of mutually beneficial relationship mutualism.

This week, in the cover story in the journal Science, University of Florida researcher Todd Palmer describes a fascinating mutual relationship that he has been studying in Kenya, and how quickly it can be disrupted.

PALMER: "The classic work that was done on mutualism was by a guy named Dan Janzen at the University of Pennsylvania. And he studied an acacia species in Central America and its ant associates, and was the first scientist to demonstrate that, the ants were, in fact, protecting the tree from encroaching vegetation and also protecting the trees from herbivores. And in exchange, the plants were providing housing and food for the ants."

Q: In your paper you took advantage of something called the Kenya Long Term Exclosure Experiment, not enclosure but exclosure. Was that originally designed to do the sort of study that you did, or was that set up for some completely different reason?

PALMER: "One of the things that ecologists do a lot of is throw up fences. You know, build fences, keep things out of areas and see what happens to the communities inside. The original intention of the Kenya Long-Term Exclosure Experiment was just to manipulate different groups of herbivores, so everything from livestock to big animals like elephants and giraffes, and then the intermediate size critters as well, like zebra, buffalo and things like that."

Q: Did you set out to look at the influence of the exclusion of the herbivores, or did you simply notice ? How did the idea generate here?

PALMER: "It stemmed from one of the most obvious things that I had managed to miss on a daily basis for about eight years. (laughs) I was walking down the road next to the exclosures one morning, and I suddenly realized that the trees where the herbivores were present looked healthy and vigorous. And when I looked to my right, to the trees on the inside of the electrified fences, they looked like they were in very bad condition. And that struck me as a little paradoxical because my intuition was that if you remove herbivores, if you remove something that feeds on a tree, you'd expect the tree to start to flourish and do well, and what I was seeing was sort of the exact opposite of that."

Q: So, what's the mechanism here? How are the ants and these acacia trees benefiting each other?

PALMER: "Essentially what the trees are doing is producing these bulbous swellings, which are called domatia, and they're essentially ant housing. In addition, the trees produce a sugary solution and the ants forage on that nectar and use that as one of their sources of carbohydrates. In exchange, the ants, in an ideal world, are supposed to be protecting the tree from herbivores. And when you disturb the tree, they essentially come running out and swarm onto the offending creature and basically they aim for the mucous membranes, so they go for the eyes, they go for the insides of the nose, (laughs) various things like that, as well as the lips and inside of the mouth. So it's an unpleasant experience to have hundreds of ants swarming onto you, and so what that does is essentially reduce the duration of the feeding bouts by these herbivores that are so fond of eating these trees' leaves and branches."

Q: Since the ants are there to protect the trees from the herbivores, it seems, one would think, that if you fence out the herbivores, then the trees should thrive, but they don't. Why is that?

PALMER: "That's an excellent question, and essentially what seems to be happening is that the trees over a period of somewhere between five and ten years start to realize ? however it is that a tree realizes something ? that the herbivores are no longer around, and so what they do is they start reducing their investment or their payment to these ant-bodyguards, so they start producing fewer of these bulbous homes and they start producing fewer of these active nectaries that secrete the sugar-like solution as a way of sanctioning the ants because they no longer have as great a need for the ants' services."

Q: Is there a larger message in this paper in particular and this sort of research in general?

PALMER: "Yeah, I would say there's a couple of larger messages. The cautionary tale is that while mutualisms are very, very slowly done, they can be very rapidly undone. And in the face of global climate change and the acidification of oceans and, you know, all the kind of human-induced alterations of the world's landscapes, we don't really have a good sense of what those large scale manipulations are going to be doing. It's basically a big, unintended experiment, the consequences of which could be not so good for us, especially because as humans, we rely pretty heavily on a lot of different mutualisms from pollination of agricultural crops to fisheries that rely heavily on coral reefs as sites for young fish to develop. So the potential for sort of collapses in these mutualistic relationships as we change the environment is great, and the speed with which those relationships can collapse sort-of makes your head spin."

We reached Todd Palmer at the Mpala Research Center in Kenya. He paper on ants, acacia trees, and plant-eating animals was published Thursday in the journal Science.


This was the week of the big Consumer Electronics Show in Las Vegas. When I say big, I mean: 2,700 exhibitors spread over the enormous convention center plus three huge hotels, with some 140,000 people attending, representing countries from Argentina to Zambia. There may have been no single break-out product this year, but as we'll hear, there were new products galore in lots of categories. Our report was written by Faiza ElMasry and read by Faith Lapidus.

LAPIDUS: Since 1967, the Consumer Electronics Show has been providing a platform for technology developers and manufacturers to showcase their newest innovations and inventions. Technology trend expert Brian Cooley says the novelties at the 2008 Consumer Electronics Show are no less revolutionary than previous years. They include a car that drives itself, an intelligent bed that uses vibration to stop insomnia, and a smart automobile navigation system.

COOLEY: "[You have a] GPS navigation unit that you might have stuck to your windshield, then add Internet to that wirelessly, so you can search for things that you need right from the navigation screen. And then also get directions to go find whatever it may be, maybe a store or a restaurant."

LAPIDUS: Cooley says you don't need a GPS navigation system to find other cutting-edge products at the show.

There is a new refrigerator from Whirlpool that's equipped with a multi-port docking station for charging gadgets like iPods and computers, a home surveillance robot made by WowWee that can be controlled via the Internet through a mobile phone, cell phones that function more and more like computers, and, of course, new ways to watch TV.

COOLEY: "I'm seeing devices that let you download television programming from the Internet and display it on TV in high quality."

LAPIDUS: Wireless is big this year, according to another analyst, Drew Krasny. He singled out the high definition TV by Phillips.

KRASNY: "It's a frameless television set. There is a smooth and clean edge around their HDTV [High Definition TV]. No speakers anywhere to be seen. It's all coming from the sides and the back of the television set."

LAPIDUS: Krasny says the company has won numerous awards for the Amba sound technology it developed.

KRASNY: "Ambasound actually simulates Surround Sound. So, in their home theater system sound bar are 6 speakers in this little bar that fits perfectly under your flat screen TV that shoot invisible sound throughout your room without any wires whatsoever. So you are able to have rich sounding [audio], the bangs and pops of bullet firing, the cats and dogs jumping off the roof in these cartoons that we watch. You just get this crisp, wonderful sound."

LAPIDUS: What's so significant about the annual Consumer Electronics Show, Krasny says, is it provides a formal, large-scale launch pad to introduce products that incorporate new technologies. As an example, he points to Lenovo's latest laptop computer, which uses facial recognition technology.

KRASNY: "You can actually use your face as your password. I am so impressed with that technology! Do you know what this means? It means that it's around the corner that we just go to the ready-teller at the bank or at the grocery store, buying groceries, and we just use our face as our identification!"

LAPIDUS: The latest hi-tech gadgets will soon be moving off the show floor in Las Vegas to stores around the world. In general, they will be offered at prices that only wealthy enthusiasts are willing to pay. But once they satisfy that market, says hi-tech expert Brian Cooley, retailers will bring the prices down, making these technologies more available for the average consumer. I'm Faith Lapidus.


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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
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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 or on your radio next Saturday and Sunday as we check out the latest in science and technology ... in Our World.