Our World — 26 May 2007

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," stormy weather ahead: a hurricane season forecast ... how some infants can tell what language they're hearing just by looking ... and a contest to explain very complex science in a two-minute video

KENIGSBERG: "They were interesting and they had different takes on this, and there was a lot of real creative kind of views into how does this theory work, and what's it mean about matter in the universe."

Those stories, screening for colon cancer, and more. I'm Art Chimes. Welcome to VOA's science and technology magazine, "Our World."

U.S. weather forecasters say they expect the North Atlantic hurricane season to be more active than normal, including three to five major storms. Those projections were announced Tuesday by the head of NOAA — the National Oceanic and Atmospheric Administration — Conrad Lautenbacher:

LAUTENBACHER: "We are right now in a, what we call a period of more active hurricane seasons. We are forecasting 13-17 named storms, of which 7-10 will become hurricanes, and 3-5 of those hurricanes will be in the 'major' category or Category III strength and higher."

NOAA doesn't predict landfall this far in advance. But lead climate forecaster Gerry Bell said seasons like the one they're predicting typically have two to four hurricanes reaching the U.S. mainland and two or three in the Caribbean.

BELL: "However, it is important to note that it's currently not possible to confidently predict at this time — or at these extended ranges, really — the exact number or intensity of landfalling hurricanes, or whether a given locality will be impacted this season."

The forecast of an active hurricane season is based in part on reports of warmer surface temperatures in the Atlantic. Storms pick up heat from the ocean, which is their energy source. It's one reason why many climate experts say global warming may lead to more severe storms.

It was almost two years ago that hurricanes Katrina and Rita slammed into the U.S. around New Orleans, battering the city and overwhelming the area's flood protection system. Much of the city was inundated, and large tracts of the city remain uninhabitable.

The physical devastation is easy to see, but the storms and their aftermath have also taken their toll on the health of residents. As VOA's Rosanne Skirble reports, it is something that concerns members of Congress from the area, the Gulf Coast Recovery and Rebuilding Caucus.

SKIRBLE: Representative Bennie Thompson invited medical experts to a briefing room in the U.S. Capitol for an update on the state of public health in the Gulf Coast region.

Thompson told the experts what they already knew. People living in trailers have been complaining of coughing, bloody noses, runny eyes and headaches. The culprit turns out to be formaldehyde, a chemical carcinogen found in particleboards in the trailer floors and cabinets.

SINKS: "We know it's a problem. Maybe this should be a part of our planning, so we don't recreate the problem."

SKIRBLE: That's Tom Sinks, with the U.S. Centers for Disease Control and Prevention in Atlanta, Georgia. He says the CDC has made recommendations on how best to vent the government-supplied trailers for the 86,000 people still living in them. He says properly vented, the trailers pose no medical problems.

Louis Hall discussed his study on soil samples. The associate professor of environmental health at Mississippi Valley State University [in Itta Bena, Mississippi] has studied sediments submerged by floodwaters.

HALL: "I took a sample from a baptismal pool at a church because the church was flooded. I took samples in graveyards. Why graveyards? Well, on tombstones when the water recedes it leaves some soil."

SKIRBLE: Hall expressed particular concern about the lingering effects of the toxic stew of chemicals and fecal matter spread widely by New Orleans' floodwaters. Hall said that while he did find a variety of chemicals in floodwater samples, toxicity levels were low.

HALL: "None of them were carcinogenic."

SKIRBLE: Hall's findings echo a large sediment study by the U.S. Environmental Protection Agency. The work confirms results reported by the National Academy of Sciences that pathogens first detected in New Orleans floodwaters had returned to pre-hurricane levels.

Hall says a more pressing public health issue is water quality in rural areas not served by public water systems.

HALL: "They have wells. And all these chemicals and other material is getting in that water system. That is a major problem."

SKIRBLE: It's a problem that Hall recommended for further study. Maureen Lichtveld, who heads the Department of Environmental Health at Tulane University in New Orleans, says the real danger in all this widely scattered debris comes from the dust particles it throws off.

LICHTVELD: "And the larger ones [particles] we cough up, and that was the cough that we called the 'Katrina Cough.' That is the one we should be less worried about. The smaller ones are the ones that actually go into the lungs. That's the ones we're worried about."

SKIRBLE: Lichtveld is leading a new study on how children with asthma are affected when they return to moldy, flood-damaged homes.

LICHTVELD: "Now what happens if somebody is allergic and will react to formaldehyde, and at the same time also reacts to mold, and at the same time has asthma. Those are the long-term environmental health issues that we need to address."

SKIRBLE: Lichtveld reminded the Congressional lawmakers that no regulations or standards exist for indoor pollutants like mold or formaldehyde. She says she hopes studies like hers can lead to better-informed public health policies in response to disasters like Hurricane Katrina. I'm Rosanne Skirble.

Another health threat now. Tuberculosis kills an estimated 1.6 million people a year. It is especially deadly in people who are also infected with the AIDS virus, HIV. Drugs exist to treat tuberculosis, but as we hear from health reporter Rose Hoban, drug-resistant varieties of the TB bacteria are getting even more resistant.

HOBAN: The bacterium that causes tuberculosis grows extremely slowly. As a result, TB patients need to take antibiotics for many months in order to kill all of the bacteria. But many patients fail to complete their courses of therapy — and that has given the TB bacteria an opportunity to evolve into more virulent forms. This 'multi-drug resistant', or MDR-TB is harder to treat, and is already resistant to isoniazid and rifampicin — the two most common drugs used to treat the disease.

Dr. Sushil Jain from the Hinduja National Hospital in Mumbai, India, says that for several years, he's seen forms of MDR-TB that are even more resistant to treatment. Last year, the World Health Organization identified these bacteria as 'extremely drug resistant' or XDR TB.

JAIN: "It's really difficult to treat these types of patients. And we have very few drugs left to treat these patients and the mortality is further increased on treating these patients."

HOBAN: Jain looked at all suspected tuberculosis samples sent to the Hinduja hospital lab over one year and found that about a third of the cultures were positive for multi-drug resistant TB. Furthermore, he found that about 9 percent of those MDR samples were actually XDR-TB.

JAIN: "XDR TB was more common among [the] younger age group, with a mean age of about 30 years. This is important because this age group is [an] economically productive population, and if these patients suffer from this form of the disease, then it is not good for the community."

HOBAN: Jain says what's especially worrisome is that XDR TB is more deadly than both normal TB and MDR TB, and its prevalence is increasing worldwide.

JAIN: "At the end of one year, about 40 percent of the patients have already expired. However, this is less than the previous study, which was done in Africa. But in that study, it was mainly in a HIV positive population, while our study is in the general population, so that's the difference, probably."

HOBAN: Jain says more research must be done to better assess the extent of XDR TB in India. He presented his research at the American Thoracic Society International Conference in San Francisco last week. I'm Rose Hoban.

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

More than 400 years ago the first microscopes were built in the Netherlands. Today, microscopes are one of the most fundamental tools of science, and standard equipment in many classrooms, research labs and factories.

For practical tips on using microscopes and a stunning gallery of microphotographs, take a look at Molecular Expressions, online at microscopy.fsu.edu.

DAVIDSON: "There's over 700 review articles on all the various aspects of microscopy. As a matter of fact in some universities it's replacing textbooks. But there's also interactive tutorials that help students actually learn the basic concepts, make it much more simple than trying to read through texts and think in their minds how these things work."

Michael Davidson runs the Molecular Expressions website at Florida State University.

He says most of the visitors to the site are students of one sort or another, from youngsters all the way up to advanced biology graduate students, who come looking for help in mastering the latest microscopic imaging techniques to get them through their studies or research.

DAVIDSON: "Many of the biology students who visit the website are more interested in their biology, as they should be, rather than microscopy, and so what we try to do is serve as a vehicle so that they can quickly understand the concepts that are going to be necessary for them to do their experiments."

Some of the microphotographs have an exotic beauty, and in fact Molecular Expressions' other role is as an online store to sell images for both scientific and artistic purposes, and sometimes it's hard to say which is which.

DAVIDSON: "When you look through the microscope and you see these wonderful, colorful patters and features, that does have an artistic sense to it. And I've seen some of this abstract art that very much resembles what we see in the microscope, and in that sense I guess you could call this art."

Whether your interest is the techniques of microscope use, the science that microscopes can reveal, or the captivating images — and for some great ones be sure to check out the Silicon Zoo — your destination is Molecular Expressions at microscopy.fsu.edu, or get the link from our site, voanews.com/ourworld.

MUSIC: "Micro-Polka" - ad vielle que pourra

And you're focusing in on the fine details here at VOA's science and technology magazine, Our World. I'm Art Chimes in Washington.

Scientists have always thought that babies learn languages by hearing them, but a new study provides evidence that infants as young as four months can distinguish between different languages being spoken by using visual cues. VOA's Jessica Berman explains.

BERMAN: Researchers at the University of British Columbia found that babies can tell when a speaker has switched to a different language by watching the speaker's face.

Investigators say babies do this by studying the shapes and rhythm of mouth and facial movements.

Researcher Whitney Weikum is with the University of British Columbia in Canada.

WEIKUM: "A lot of studies have just addressed the auditory properties of speech and so we were just interested to see whether this visual information is playing any sort of a role when babies are learning to perceive language."

BERMAN: Weikum and colleagues studied four-, six- and eight month-old infants from both monolingual English homes, and bilingual households where both English and French is spoken.

Each group of babies was shown silent video clips of three bilingual French-English speakers, who mouthed sentences first in one language and then in the other. Then the speakers switched languages.

Weikum says investigators found that babies who are raised in English speaking homes could distinguish English and French at four and six months of age by staring intently at the videos. But by eight months, they became fidgety and paid less attention to the images.

At the same time, eight month-old infants raised in bilingual households maintained their ability to distinguish between French and English by staring at the speaker.

Researchers concluded that babies raised in English-only households lost their ability to discriminate language based on visual cues because they no longer needed them, while infants in bilingual homes continued to depend on visual cues to discern which language was being spoken.

Weikum says the study is the first to show the importance of visual information in infants' language development.

WEIKUM: "It says that very early on in infancy they are prepared to discriminate multiple languages just using visual cues, and depending upon their experience with visual cues, they either maintain or experience a decline in their ability to discriminate the language visually."

BERMAN: The study was published this week in the journal Science. Jessica Berman, VOA News, Washington.

The American Dental Association has long advised brushing your teeth twice a day, flossing every day, and seeing your dentist twice a year. Now the leading dental group is also stressing the use of an antimicrobial mouthwash, or mouthrinse, to kill the germs that can contribute to the gum disease known as gingivitis. Dr. Sebastian Ciancio of the State University of New York at Buffalo Dental School says research supports the recommendation.

CIANCIO: "There's a strong body of scientific knowledge, which supports the role of bacteria in causing gingivitis and the benefit of antimicrobial mouthrinses in fighting these bacteria."

The American Dental Association recommendation is especially important to the elderly or others who might find swishing around an antimicrobial mouthwash is easier than thorough brushing and flossing. The ADA also says a healthy diet is important for good dental health.

We do the entire digestive system on Our World. Full end-to-end coverage:

It's been Digestive Disease Week here in Washington. No, that's not an official proclamation. Actually, it's the name of one of the country's biggest medical conferences, with around 20,000 people attending.

One of the main topics was colon cancer. According to the World Health Organization, its the third most common form after lung and breast cancer. More than 900,000 new cases are diagnosed each year, and 650,000 people die from it.

Colon cancer is sometimes called a disease of civilization, meaning so-called civilized countries where people eat a lot of processed foods and don't exercise much are more likely to have higher rates of colon cancer.

It's a disease that can often be treated successfully if caught early, and the best way to do that is with a colonscopy.

In the 1990s researchers found that colonoscopies failed to identify more than one-fifth of suspicious areas, raising serious concern about the procedure.

But now, new research by Dr. Roy Soetikno of Stanford University indicates that the "miss rate" has come way down, to around 12 percent.

SOETIKNO: "When you look at the prior historical data, this is a significant reduction. None of the missed lesions — all of them were smaller than 10 mm — was a significant lesion, meaning there is really no cancer being missed."

Soetikno said the improved rate of spotting suspicious areas in the colon comes in part from better equipment, such as more flexible scopes and tiny water jets that away debris for a better view. Also, says Prof. Don Rockey of the University of Texas Southwestern Medical Center, doctors are getting better.

ROCKEY: "We now understand that we miss lesions. And I think in practice, you know everyone's familiar with the New England Journal of Medicine paper that came out [in 2006] and said we do colonoscopy too quickly. I think now, as quality becomes important, we're being more careful, and I think that the miss rates are actually going to be lower because of that as well."

Risk of colon cancer increases with age, and doctors have often reluctant to subject older patients to what can be an unpleasant experience, especially the heavy-duty laxative needed to clean out the bowel before the actual colonoscopy. But Dr. Kinesh Patel of Imperial College London says his study of older patients shows they should not be denied the benefits of this effective colon cancer screening.

PATEL: "There are risks of having heart attacks and all those sorts of things in relation to the procedure, but generally it's actually been shown to be pretty safe, and our fears are probably greater than the benefits of doing the procedure."

A substance called C-reactive protein shows up in the blood when inflammation is present, and that's the case in numerous diseases. Researcher Han-Mo Chiu of the National Taiwan University Hospital found higher levels of C-reactive protein in women with non-cancerous growths in the colon called adenomas — in women, but not in men. Especially in countries where medical resources are limited, he said that fact might help screen patients for possible colonoscopy, as one of a number of factors that would also include lifestyle issues.

CHIU: "Life habit or family history, personal history. And we can pick up the higher risk group who should be receiv[ing] endoscopic screening. So this may be useful for developing country, I think."

The WHO says colon cancer is 10 times more common in industrialized countries than it is in the developing world, but that may be changing as Western lifestyle - and diet - spread.

How long would it take you to explain a complex scientific concept? Think you could explain, say, string theory in ... two minutes? Well, some 45 video makers gave it a shot in a contest sponsored by New York-based Discover magazine. Of the eight finalists on the magazine's website, some are very professional looking productions, while others look, well, a little more homemade.

WATSON: "String theory combines the mathematics of waves and particles by saying that everything is made of tiny, vibrating strings. Different vibrations cause the strings to appear as, or have the properties of, different particles."

That's one of the Watson kids, four children from a family in a Washington suburb, who take turns explaining the fine points of string theory. Their video, called "The Problem with Math," was getting the most votes in an online poll.

A somewhat slicker entry featured an animated rubber-duck bathtub toy to help illustrate some of the ideas behind string theory. As you learn from watching "String Ducky," ordinary string vibrates and makes a sound.

DUCKY: "Now, imagine a string a billion, billion times smaller than an atom. When it vibrates, instead of making a sound, it manifests as a particle."

Sandy Chase, who created "String Ducky," had previously written science stories for children. He chose the bathtub toy familiar to most American families to provide some human scale to the concept.

CHASE: "If you're working with something on a cellular level or an atomic level, it's good to relate it back to something that is on a human scale. And if you zoom in far enough with your magical animation microscope - as if there were such a thing - then you'll see the little atoms and quarks and I guess the strings eventually."

Discover magazine web editor Amos Kenigsberg said entries were slow in coming, and at the magazine they worried that maybe explaining string theory in just 120 seconds was just too hard.

KENIGSBERG: "Judging by the videos that we got, I would say that people could do it. And I was very happy, especially with the eight finalists. I felt like they were interesting and they had different takes on this, and there was a lot of creativity, not just explication of the science but real creative kind of views into how does this theory works, and what [does] it mean about matter in the universe."

You can watch the finalists and vote for your favorite on DiscoverMagazine.com. The winner, as judged by Columbia University string theory physicist Brian Greene, will be announced in a few days.

MUSIC: "Our World" theme

That's our show for this week. We're always interested in your comments or your science questions. Email us at ourworld@voanews.com. Or use the postal address -

Our World
Voice of America
Washington, DC 20237 USA.

Rob Sivak edited the program. 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.