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" ... bringing developing countries online ... the downside of improved access to AIDS drugs ... and powering artificial muscles.
BAUGHMAN: "There is interest in using our artificial muscles for what's referred to as exo-skeletons, which could enable, for example, an astronaut to be able to perform superhuman feats."
Those stories, great women on 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 announced another delay in the space shuttle program. The shuttle fleet has been grounded since last July after foam pieces fell off the spacecraft's external fuel tank during launch. It was just such breakaway pieces of foam that fatally damaged the Columbia orbiter on its launch in 2003, causing the spacecraft to burn up on re-entry and killing all seven astronauts aboard.
This latest delay was prompted by concerns about fuel sensors inside that external tank. The sensors tell the engines to shut off when the fuel tank is empty, and shuttle manager Wayne Hale says a failure of the sensors could be dangerous.
HALE: "So from the potential to cause problems, obviously you want to shut the engines down if you're running out of gas, but you don't want to shut the engines down early if you're not running out of gas. It's kind of either way, you can get in trouble."
The new launch target date is July 1.
Also this week in unmanned space exploration, scientists said they were surprised by bits of material from the comet Wild-2 which an American spacecraft brought back to earth in January. Although the comet was formed in the frigid reaches near the edge of the solar system, some of the comet dust bore the unmistakable signs of having been formed at extremely high temperatures. Scientists theorize these particles could have formed in a distant star before finding their way into our galactic neighborhood. NASA scientist Michael Zolensky says another possibility is that they were formed in our own sun.
ZOLENSKY: "If these are really from our own sun, they've been ejected out all the way across the entire solar system and landed out there. And that means these materials were basically on a big conveyor belt being shot out and then gradually drifting in and being shot out again."
The source of those mysterious particles is still unknown, but the scientists working on the comet dust say they're confident they have the tools to figure it out.
According to the World Health Organization, diseases caused by parasites afflict up to one third of the world's population and severely sicken an estimated 300 million people every year. There are treatments for parasitic diseases, but they are far from perfect. Now, researchers have discovered a new way to attack the parasites on a molecular level. VOA's Jessica Berman reports.
BERMAN: Scientists at the University of Texas Southwestern Medical Center in Dallas discovered that, much the same way hormones are responsible for sexual maturity in humans, a hormonal process leads to the maturity and reproduction of worms.
Researchers identified the hormone-like molecule, called a ligand, in the pinhead-sized worm, C elegans, which lives in the dirt, making it similar to parasites that cause disease in two billion people around the globe.
They found that when the hormonal ligand binds with a nuclear receptor inside the cell, called DAF-12, the process triggers the activation of growth genes in the worm.
When researchers blocked the process by engineering mutant worms, the parasites went into a resting state that halted their growth and sexual maturation, according to David Mangelsdorf, the study's lead author.
MANGELSDORF: "In humans, the idea would be to keep it from going into its reproductive cycle. And that would eventually cause the worm to die out."
BERMAN: Mangelsdorf notes there are drugs known as anthelmintics available to treat worm infections. But he says the drugs have some toxicity, and often have to be given repeatedly. Mangelsdorf says that raises concerns about the drugs losing their effectiveness.
MANGELSDORF: "That's unlikely to occur in this hormone receptor pathway because you are mediating a physical pathway that is native to the worm. You're not targeting a different pharmacologic pathway."
BERMAN: Mangelsdorf says he expects the latest research will result in new anti-parasitic drugs in the not so distant future.
The study on the discovery of the worm hormone is published in the journal "Cell." Jessica Berman, VOA News, Washington.
There's some surprising new research published this week that illustrates how difficult it can be to attack major public health problems.
For many people in wealthy countries, HIV/AIDS is now a chronic condition, rather than the death sentence it was two decades ago. Anti-retroviral drugs can control the disease, but they are expensive. In developing countries, however, only an estimated 10 percent of people who could benefit from these drugs are actually getting them. The World Health Organization and other organizations have set a goal of universal access to AIDS drugs by the end of the decade. But researchers at Imperial College in London have developed a mathematical model that indicates that merely making medicine available may not reduce infection rates.
Lead author Rebecca Baggaley says an effective anti-AIDS program must includes both medicine and a public health infrastructure that counsels people on how to limit their exposure to HIV — for example, by practicing safer sex.
BAGGALEY: "And the WHO is envisaging very, very large-scale roll out of anti-retroviral therapy where this kind of infrastructure will not be available, and, therefore, the very long extension of life expectancy that we've seen in industrialized countries might not be the same [in developing countries]."
To try to predict various outcomes of anti-viral therapy in resource-poor countries, Baggaley and her colleagues developed a computer model of HIV conditions in the sub-Saharan Africa nation of Malawi.
She says even with AIDS drugs, the model predicts HIV-positive individuals in developing countries are unlikely to do well because they tend to be diagnosed at a late stage in the disease.
Baggaley cited the example of the United States, where the widespread use of antiviral drugs led to an increase in unprotected sexual activity among HIV-positive gay men. Her study was published in the journal "PLOS Medicine."
The World Health Organization this month reported an outbreak of meningitis in Kenya. The number of cases is relatively small, but the fatality rate is 20 percent. Now, a new vaccine holds out hope of protecting against meningitis in Africa. It has passed its first major testing hurdle in India with very good results. And as we hear from VOA's David McAlary, the next round of tests will focus on Africa.
McALARY: The world is blanketed with disease organisms called pneumococcal bacteria. They cause a variety of common mild ailments like ear and blood infections. But they also induce life-threatening ones like meningitis, an inflammation of the thin layer of fluid that surrounds the brain and spinal cord.
Meningitis vaccines exist, but they do not provide long lasting protection and are not very effective in children. The U.S. government's drug regulating agency, the Food and Drug Administration, created a new vaccine to overcome those problems. A version for the meningitis strain that afflicts sub-Saharan Africa is in the testing phase.
LaFORCE: "The vaccine is important because of the repeated epidemics of meningococcal meningitis that sweep across sub-Saharan Africa."
McALARY: Physician Marc LaForce directs the program that is developing the new vaccine, the Meningitis Vaccine Project. It is a partnership between the World Health Organization, a U.S. non-profit group in Seattle called the Partnership for Appropriate Technology in Health, and the Serum Institute of India, a drug maker.
LaFORCE: "Annually there are small epidemics throughout the meningitis belt, but about every 10 or 12 years, there are these major epidemics that cause literally tens of thousands of cases. The last epidemic was in 1996-1997, with over 180,000 cases with 20,000 deaths."
McALARY: The meningitis belt ranges from Senegal and Gambia in west Africa to Ethiopia in the east. At risk are about 430 million people.
Antibiotics help against the disease, but at least 10 percent of patients die. As many and even more are left with permanent problems such as mental retardation, deafness, and epilepsy.
That raises the importance of vaccines to prevent meningitis. A vaccine works by introducing bits of disease into the body to train immune system cells how to attack when the germ invades on its own. But available meningitis vaccines usually do not work in infants and children, who are the bulk of meningitis patients, because parts of their immune system are too immature to react. To get around this, project scientists added a tetanus protein to the new vaccine that is recognized by better-developed segments of young children's immune system.
Dr. LaForce says the vaccine performed well in recently completed clinical trials in the Indian cities Hyderabad and Bombay, also known as Mumbai.
LaFORCE: "The results met every one of our expectations. The vaccine was safe and, very importantly, the immune response in infants and toddlers was good."
McALARY: Unlike the existing meningitis vaccine, which protects only those inoculated, the experimental one blocks transmission of the disease in a population, so people who have not been immunized are also protected.
The next phase of tests is being planned for Africa. LaForce predicts that if it goes well, the vaccine could be available on the continent in three or four years at the very low cost of 40 cents per dose.
He says the Serum Institute of India agreed to that price after the Meningitis Vaccine Project conferred with African health and finance ministries about what they could afford.
LaFORCE: "We were told that if we were able to develop a vaccine at less than 50 cents a dose, this would be a product that could be folded in to the general health budgets in these countries and would virtually guarantee sustainability once the vaccine was introduced."
McALARY: LaForce says he believes that the new meningitis vaccine will reduce the incidence of the disease by a third to a half in countries where it is used following testing. David McAlary, VOA News, Washington.
March is Women's History Month in the United States. To mark the occasion, Our World's Website of the Week salutes an online collection of speeches by famous women at giftsofspeech.org.
KENT: "Gifts of Speech is a website that I started in October of 1996, and we collect speeches by contemporary, inflential women on the website and offer them out to the world for free."
Liz Kent is a librarian at Sweet Briar, a women's college in Virginia. She says it is especially important for young women to have access to the words of prominent women who have made a difference.
KENT: "I think that it is important for them to be exposed to the fact that women's words matter, women's words change the world. And just so they'll know how important women have been in the history of the world."
The Gifts of Speech website has almost 500 speeches now, just the text, not audio or video. A decade ago, when the site first launched, the text-only format reflected limits to the technology. Now it's more a matter of funding. But even in written form, Kent says speeches resonate differently than other kinds of writings.
KENT: "Speeches, you always think of a speech as being made by someone who is important. They kind of have this built-in 'wow' factor, it's kind of a built-in respect because this was a speech that someone made and someone stood up and gave it and people sat in chairs and listened to it usually."
The timeline begins with pioneering American women's rights crusader Elizabeth Cady Stanton and carries through to the 21st century and a speech by animal rights advocate Ingrid Newkirk. Most of the women featured are American, but the list also includes Mother Theresa, Marie Curie and many other Nobel laureates.
Great speeches by great women online at giftsofspeech.org, or get the link from our site, voanews.com/ourworld.
MUSIC: Waterlillies: "I Am Woman"
It's VOA's science and technology magazine, Our World. I'm Art Chimes in Washington.
In the journal "Science" this week comes news of artificial muscles. That's not a new concept. But researchers at the University of Texas have devised two new technologies for artificial muscles that run on liquid fuel, not electricity.
For a muscle — natural or artificial — to do work, it has to deform or change shape, and it has to be able to generate some force.
Researcher Ray Baughman says that, compared to battery powered artificial muscles, the new materials can run longer on liquid fuel, such as methanol, and can support much more powerful flexing than natural muscles.
BAUGHMAN: "For example, our fuel-powered shape memory artificial muscles can provide strains of over 200 percent, and they can generate forces about 100 times higher than would be possible for the same cross section natural muscle."
This sounds like the stuff of science fiction, but Baughman explained how this new material could be used.
BAUGHMAN: "There is interest in using our artificial muscles for what's referred to as exo-skeletons, which could enable, for example, an astronaut to be able to perform superhuman feats. Or an individual who doesn't have use of a limb, to use very weak movement, for example of fingers, and have them amplified by a structure which is exterior to the limb."
Q: So in the case of a person with a disability, rather than some sort of implantation, it would be like something you would wear?"
BAUGHMAN: "It's something you could wear."
Ray Baughman of the University of Texas says some products using the new material could come to market in as little as three years. Some of the funding for his research comes from the Defense Department. I thought that might be for battlefield robots, but actually he said the military interest is in rehabilitating wounded troops.
A year ago on Our World we spoke with MIT's Nicholas Negroponte about the $100 laptop computer he hopes to introduce in developing countries.
The dream of bringing affordable computing and Internet access to poorer nations remains alive. In the United States and other wealthy countries, Internet access is by no means universal, but it is pretty common. In less affluent areas, it's another matter entirely. Out of a global population of six billion people, only about one billion are online.
Among those who want to change that is Hector Ruiz. Born in a small village in Mexico, Ruiz went on to earn a doctorate in electrical engineering and is now head of Advanced Micro Devices, or AMD — along with Intel, one of the world's two biggest makers of microprocessors.
Speaking in Washington at a meeting of the Congressional Internet Caucus this week, Ruiz hailed the social and economic impact of computing technolgy and the Internet.
RUIZ: "It has become, really and truly, the single most important event in the last 20 years that enables a lot of innovation around the world, as well as a lot of economic growth, because in reality it is an economic engine. And it doesn't matter if you're in agriculture or if you're in medicine or in rocket science, the technology that is driving all of the progress and changes in any of the segments of industry, are driven by computing technology or information technology."
In a pilot project in Sao Paolo, Brazil, for example, Ruiz says an Internet kiosk in a community center gets a half-million customers a month. To illustrate the kind of change that Internet access can bring, he used the example of a computer lab he set up in his old elementary school in Mexico.
RUIZ: "And this is a school where half of the children go to school barefoot. And we put this little computer lab in this place for the kids to have access to the Internet. Now these are kids who have never seen a computer, had never even realized what it was. But I can tell you that within minutes, these kids could surf the Net, could look for information, could learn faster [and] quicker than you would ever imagine they could. And on one hand, the thing that's very positive is that they talk about their dreams. They want to be doctors, engineers and lawyers. The negative side is that there's no path for them to follow."
AMD is leading a program known as 50x15, to have 50 percent of the world's population online by 2015. But Hector Ruiz told me that developing countries can not be viewed as a monolith. Different countries are, well, different, and so the technology may need to be different.
RUIZ: "You know, in a lot of these developing countries, the infrastructure is limited, and so it is important to adapt to that environment. For example, there are places where a solar power generator may be more valuable in a village than trying to connect to electrical wires, because they don't exist. So because of things like that, you have to make adjustments. And unfortunately there is not an answer that applies to all the developing regions. Each one is different. And I think if you make the investment and understand it and take that into account, then you can really develop a unique ecosystem for each of those regions that will work."
Q: And you think it's really feasible to bring another two billion people online in just another decade?
"I believe so. I really believe that the momentum for this need to connect is just going to skyrocket in the next 10 years. And I think that momentum, accompanied by companies that understand what's needed and required, particularly in terms of affordability, can really successfully lead to that."
Hector Ruiz, CEO of Advanced Micro Devices, a company that obviously hopes its chips will power the computers needed to triple the existing number of Internet users by 2015.
And finally today ... Tuesday was March 14. Here in the United States we often write that in numbers as 3-14. That's the start of one of the most famous numbers in mathematics, which is why a lot of math classrooms observed March 14 as "pi day."
Mathematicians find beauty in pi, and for the rest of us, it may be one of the few — things we remember from math class, for example in the formula for the area of a circle — pi r-squared, pi times the radius multiplied by itself. Pi has even inspired entire books, including one by the dean of the school of education at the City College of New York, Alfred Posamentier, who says the concept of pi goes back to Biblical times.
POSAMENTIER: "Now the Old Testament, the same sentence comes up twice describing the pool or fountain in King Solomon's courtyard. And it describes it as being 30 cubits around and 10 cubits across. Well, if you take that quotient you get three."
Mathematicians call pi an irrational number, that is, it can not be exactly written in decimal form. Usually, something like 3.1416 will be good enough, but the decimal places can go on and on. There is something of a sport in computing out the value of pi to a large number of decimal places. More than a trillion decimal places by now, all apparently random numbers.
Posamentier's book is "Pi: A Biography of the World's Most Mysterious Number." It includes, among other things, the story of how a 19th century U.S. state legislature almost enacted a legal formula for pi.
POSAMENTIER: "If you follow this guy's calculations, you get such values as 4, or you could get the value 3.160494, or you could get 3.2. In other words, his algorithm was totally inaccurate."
Posamentier talks about the "cultlike following" around pi, and he may be onto something. I don't know too many other math concepts that have inspired a rap like this one, called "Lose Yourself (In the Digits)."
MUSIC: "Lose Yourself (In The Digits)"
MUSIC: "Our World" theme
That's it for this week. Drop us a line, let us know what you think. The email is email@example.com. Or write our address on an envelope -
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.