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Straight ahead on "Our World" ... Why some Americans are dying younger ... a better way to teach math ... and the battle over Internet privacy ...

ROTENBERG: "I don't think people are wrong to believe that [the existence of] a privacy policy means that their personal information won't be disclosed to others. I think businesses are wrong to believe that it provides a basis for them to disclose the information to others.

Those stories, preventing blindness with a better trachoma treatment, and more. I'm Art Chimes. Welcome to VOA's science and technology magazine, "Our World."


Smoking, high blood pressure, and obesity are big public health issues, and they are three major factors being blamed for an increase in the death rates among women in some parts of the United States in recent decades.

Researchers at Harvard University studied almost 40 years of death statistics starting in the 1960s, during which the overall death rate fell, and life expectancy increased by about 10 percent ? to 74 years for men and 80 for women.

But they also found increasing inequality around the country starting in the 1980s. In healthier areas, death rates continued to go down. But in the worst-off areas, the rate of heart-disease deaths stopped dropping as they were doing elsewhere, and death rates from other diseases, such as lung cancer and diabetes, began to rise. For almost one in every five women in these areas, life expectancy either stagnated or actually declined.

Lead author Majid Ezzati says that after steady improvements in life expectancy ? and a continued increase in most of the country ? the declines in some areas reflect a pattern not normally seen in countries like the United States.

EZZATI: "We don't associate worsening of health, worsening of life expectancy, with something that happens in a developed, high-income country. That is the sort of thing that we saw after the fall of the Soviet Union and after the social networks fell apart in Eastern Europe, for example. That is the sort of thing that we see over thee kinds long periods and what is happening with HIV/AIDS in some countries in Africa."

Ezatti called the findings in his paper a "major public health concern." His paper on life expectancy was published this week in the journal PLoS Medicine.


Trachoma is the leading infectious cause of blindness. Worldwide, 55 million people are infected. A World Health Organization campaign to combat the disease using surgery, antibiotics, face washing, and access to clean water and sanitation has not been entirely successful. But now, as VOA's Rosanne Skirble reports, a new study, published Thursday, indicates a different approach to antibiotic treatment may be more promising.

SKIRBLE: According to a study by the London School of Hygiene and Tropical Health reported in the New England Journal of Medicine, a community in Tanzania has reduced its trachoma infection rate to near zero after two years.

In a companion article, Joseph Cook, adjunct professor of epidemiology at the University of North Carolina, says he is encouraged by the findings.

COOK: "So there is great hope that the goal that WHO has set ? elimination of blinding trachoma by the year 2020 ? can be achieved."

SKIRBLE: Cook says the oral antibiotic azithromycin has been extremely effective.

COOK: "This is the great virtue of this because the previous treatment was using tetracycline ointment twice a day for six weeks. Trying to get people to do this for six weeks was very difficult. In this case there is a single oral dose and no further treatment then for another year."

SKIRBLE: WHO recommends three doses of the antibiotic. The Tanzanian community dramatically reduced its infection rate after just two doses. Cook says it remains to be seen whether similar results can be replicated elsewhere.

COOK: "When you move a program from a community of this size, of around 1,000 people, to literally millions of people, you have an uphill battle to get the attention of people to participate in the program, to accept the antibiotic, to improve facial hygiene. So it certainly is a big educational effort."

SKIRBLE: Cook says trachoma is beatable, and the victory will be much easier than the hard-won triumph over the smallpox virus.

COOK: "So although there may still be the Chlamydia trachomatis, the agent, in the community, or there might even be a case or two of trachoma, it will not occur to the extent that it will cause blindness. So unlike the many other programs, this is a program to eliminate the disease, not to eliminate the infection."

SKIRBLE: Cook recommends that countries include the single-dose antibiotic along with on-going programs designed to control other so-called neglected tropical diseases. I'm Rosanne Skirble.


The U.S. space agency, NASA, is marking its 50th anniversary this year, and as part of a recent celebration in Washington, they invited Cambridge University physicist Stephen Hawking to make the case for human exploration of space.

HAWKING: "In a way, the situation is like that in Europe before 1492. People might well have argued that it was a waste of money to send Columbus on a wild goose chase, yet the discovery of the New World made a profound difference to the Old."

Professor Hawking, you may know, has a motor neuron disease that has left him largely paralyzed and confined to a wheelchair, and he uses a computer-synthesized voice.

Without downplaying the role of unmanned space probes, he said human exploration is fundamentally different.

HAWKING: "Spreading out into space will completely change the future of the human race and maybe determine whether we have any future at all. It won't solve any of our immediate problems on planet Earth, but it will give us a new perspective on them and cause us to look outwards rather than inwards."

Hawking responded to those who suggest that, rather than sending people into space, the money should be spent to solve big problems here on Earth, like climate change. He said that even a big boost in human space programs would represent only a tiny fraction of the global economy.

HAWKING: "I am not denying the importance of fighting climate change and global warming, but we can do that and still spare a quarter of a percent of world GDP for space. Isn't our future worth a quarter of a percent?"

Hawking added that robotic space missions don't capture the imagination of the public the way human spaceflight does. Recalling the excitiement surrounding the Apollo moon missions four decades ago, Hawking said that sending astronauts back to the moon and on to Mars would have a similar effect: possibly capturing the imagination of young people and inspiring at least some of them to pursue careers in science.


If you learned mathematics the way I did, your textbook or teacher probably used a lot of examples from the real world: John has four bananas. Two trains traveling at different speeds. Divide a pizza five ways. That sort of thing.

Teaching abstract concepts using concrete examples, or so-called "word problems," just seems to make sense.

But now, researchers at Ohio State University have evidence suggesting that the best way to teach abstract concepts may be, well, abstractly.

Writing this week in the journal Science, lead author Jennifer Kaminski says while common sense might suggest that using everyday examples is the best way to teach math, there is little real evidence to back it up.

KAMINSKI: "We really observed that it is a belief, it's really just that, that to a large extent it hasn't been. So to me, I've got a background in mathematics and I do research on learning and cognition, and I thought, we really need to put this to the test."

So Kaminski and her colleagues at Ohio State's Center for Cognitive Science recruited 80 university students. Some were taught mathematical concepts using abstract shapes. The others were taught using real-world examples, like pictures of measuring cups of liquids.

Students using real-world examples seemed to have an easier time learning the concept until they were challenged to extend their newly acquired knowledge in a different situation.

KAMINSKI: "So we had students learn one of these two scenarios, and then we presented them with something else that we described as a children's game. And we said, can you figure out the rules of this game. They work exactly like the information you just learned. And what happened was, the students who learned the abstract symbols were able to transfer their knowledge and did pretty well in figuring out the rules of this game. But the students who learned in terms of this concrete scenario of measuring cups that seemed kind of nice and intuitive and helpful were not able to transfer that knowledge."

Even when students got multiple, real-world situations to learn from, the other group, the ones who learned with abstract symbols, did better at applying their new knowledge in new situations.

So what accounts for the seemingly counter-intuitive results of this study? Kaminski suggests it could be that the details of the concrete examples are more distracting than helpful.

KAMINSKI: "Those mathematical rules really are independent of measuring cups and anything you could add to the storyline. But when you learn it in that concrete context, what you end up doing is remembering all that extraneous information. And it actually distracts you from the relevant mathematical structure."

Still, don't expect math teaching to suddenly change. Jennifer Kaminski and her colleagues say they expect continued debate on how best to teach abstract concepts of mathematics.


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

As you've probably noticed, it's an election year here in America, so we'll be taking a semi-regular look at websites that focus on U.S. politics between now and the November election.

This week, it's a site that tries to bring together the latest political news from top online media, plus commentary and analysis from sources left, right and center.

BEVAN: "RealClearPolitics is the one-stop shop for political news and information on the Internet. We seek to gather the best of the best in commentary, news, opinion and analysis from all corners of the Web"

Tom Bevan is executive editor of They're probably best known for bringing together just about all the publicly available polling data, which makes it easy to see at a glance who's up and who's down, thanks to the RealClearPolitics Poll Averages.

BEVAN: "In addition to all of the data that one would need to follow, whether it's the latest polling information , whether it is the latest campaign ads or video clips from speeches or cable television shows, transcripts of important speeches. We just try to put all of that information in one place so that people can see it and choose to view what they want to view."

Bevan admits that the question of who's ahead ? the horse race, it's often called ? drives much of the news coverage, but he says that doesn't mean you can't find a lot of issues-related information on the site.

BEVAN: "We do work very hard to provide information on the various issues of the day that are being discussed, whether it's foreign policy, economics, domestic issues or international issues."

Right now most of RealClearPolitics is devoted to the U.S. presidential contest, but Tom Bevan says that later on, closer to the November election, they'll increase coverage of the numerous races for Congress and for state governorships.

An impressive collection of political news and data at, or get the link from our site,

MUSIC: Steve Fawcett ? "A Woman on the Go"

We try to earn your vote every week here on VOA's science and technology magazine, Our World. I'm Art Chimes in Washington.


Every week here on Our World we highlight some of the great things the Internet brings us. In addition to great websites, email and chat have revolutionized communication.

But there's a dark side, too.

There are bad guys trying to take your money or steal your identity. And as more and more people are realizing, we often give up a lot of information about ourselves when we go online, information we may not realize we're disclosing, but which advertisers and commercial websites can use to sell us goods and services.

Sometimes the information is openly requested: you register on a website and you fill out a form. Next time you log into the site you find ads for sporting equipment if you registered as a young man, or maybe cosmetics if you're a woman. Other times, websites and advertisers seem to magically know our interests.

They can do this because of cookies, little text files created on your computer that contain information left there by the websites you visit.

U.S. Internet service provider AOL explains the process with an online animation featuring a penguin who visits a fictional website called AnchovyGourmet. The company's chief privacy officer Jules Polonetsky explains what happens next.

POLONETSKY: "He's reading about anchovies. You sort-of see him getting this cookie that labels him an anchovy-liker. He then goes to He wants to know about global warming. He's worried; he's a penguin. Boom! There he gets the anchovy ad. The ad company reads the cookie to display an ad."

The advertiser may not know the penguin's name or address, just that he likes anchovies. The penguin ad invites viewers to check out AOL's privacy site, where visitors can read the company's privacy policy and learn more about how targeted, or behavioral advertising works.

Critics, however, point to surveys that indicate web users don't understand privacy policies, even when they are clearly stated.

One reason for that, says privacy advocate Marc Rotenberg of the Electronic Privacy Information Center, is that so-called privacy policies often aren't about preserving privacy at all.

ROTENBERG: "I don't think people are wrong to believe that [the existence of] a privacy policy means that their personal information won't be disclosed to others. I think businesses are wrong to post a privacy policy and then believe that it provides a basis for them to disclose the information to others. That's where the problem arises."

The biggest Internet company of them all, Google, has a slogan, "don't be evil," but privacy advocates have criticized them for some of their policies, such as retaining some identifying information along with your search. Google recently launched a YouTube channel with short videos explaining privacy policies in plain English.

"To improve our search results, as well as maintain security and prevent fraud, we remember some basic information about searches. So what information does Google collect? Let's find out, starting with a simple search...."

Representatives from Google and AOL, along with scholars and critics, gathered in Washington recently for a symposium on Internet privacy sponsored by the communications schools of the University of Pennsylvania and the University of Southern California.

This is an issue that government regulators are also studying, though the U.S. Federal Trade Commission, whose members are all Bush Administration appointees, has favored industry self-regulation, which is to say: requiring disclosure but not banning the collection of personal data from visitors to websites. That's despite the fact that surveys indicate that Internet users don't want their personal information collected, as FTC commissioner Pamela Harbour acknowledged.

HARBOUR: "Consumers are concerned about behavioral advertising even if they do not know the practice by name. Implicitly, we can also conclude that present consumer education efforts are lacking. Policies alone cannot cure the overall discomfort that consumers express toward the practice."

The advance of technology is making the collection and analysis of personal information easier for advertisers and commercial websites. The process continues, even though consumers may not know their information is being collected, or that their web activities are being tracked by advertisers.


And finally: The future of early disease detection may be in the hands ? or more specifically the mouths ? of researchers at the University of Colorado in Boulder. As Brian Larson reports, the school is using a unique laser technology to unite the fields of physics and medicine though breath analysis.

LARSON: The eyes may be a window to the soul, but your breath could be even more revealing.

University of Colorado Physics Professor Jun Ye says breathing into a tube at a doctor's office may one day replace some of the more costly and invasive tests currently used to detect many diseases?

YE: "If you can see many kind of molecules in a very sensitive way ? one molecule out of a billion others, and all of them in real time ? you can just imagine what kinds of applications can come out."

LARSON: But diagnosing disease wasn't the original intent of Ye's research with Optical Frequency Comb Spectroscopy?

YE: "Who would have ever related a breath analyzer to an optical atomic clock that we were developing, but it's the same underlying technology that we have been working on since 1999."

LARSON: Developed at the University of Colorado, along with the National Institute of Standards and Technology, Frequency Combs use short pulses of laser light to measure the different colors or frequencies of light.

The laser essentially combs through a molecular landscape to distinguish the personality of individual molecules. Graduate student Michael Thorpe says the molecules are a lot like radio stations, each broadcasting its own programming but on separate channels.

That information shows up in the form of a graph on a computer screen?

THORPE: "And we can tell a lot of things about the molecule just by looking at these particular spikes. We can tell how fast it's going, we can tell how it's rotating and vibrating. Lots of physics-y things that we like to study here. (chuckles)"

LARSON: Thorpe has spent the past four years working in a cramped and dimly lit basement laboratory helping Ye adapt the laser technology for breath analysis.

THORPE: "What you would do is ? breathe into a tube that would take your breath sample into the detection chamber and while the sample was inside the detection chamber we would start taking measurements."

Q: So my breath in there is trapped inside that chamber and its being bombarded by laser light?

THORPE: "Exactly, and basically what you have ? is you have a thin, um, laser beam that goes through the chamber and the idea is to make the breath pass through that particular beam. The camera is watching to see which colors are missing from the beam. When it sees the pattern of colors that are missing from the beam you can uniquely identify a molecule."

LARSON: Jun Ye's team has been able to detect the patterns of more than a dozen molecules associated with various lung diseases. Previous breath detection systems have been limited to just specific molecules like nitric oxide ? or N-O ? which is an indicator of asthma and cystic fibrosis.

But your breath contains at least one thousand different molecules every time you exhale?

YE: "We can look at other different kinds of molecules like ethane, such as ammonia, such as hydrogen peroxide and so on. So you can make essentially a pattern recognition of various sorts of molecules coming out."

REPINE: "The things that you breathe out really tell you a lot about what's going on in the lung, and not only the lung but also the whole body."

LARSON: Dr. John Repine has been working on developing new treatments for lung diseases and other ailments that can be detected by molecules from the digestive tract, liver or kidneys.

As Director of the Webb-Waring Institute for Cancer, Aging and Antioxidant Research at the University of Colorado, he's particularly interested in the increased sensitivity and selectivity of the laser equipment?

REPINE: "We may identify new molecules coming that are coming out in the breath. With this technique we can identify them, notice the pattern of change that occurs with certain lung diseases, and than perhaps assess the effect of various treatments on these changes."

LARSON: But interest is not just limited to the medical community. NASA has already called the University of Colorado about applying the technique to monitor the atmosphere on Mars, and scientists at Los Alamos Nuclear Laboratory in New Mexico wanted to know if it could be used to detect uranium atoms.

The Webb-Waring Institute will assist Ye with clinical trials on the Frequency Comb ? which could start within the next year.

For Our World, I'm Brian Larson in Boulder.


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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
Washington, DC 20237 USA

Rob Sivak edited the show. 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.