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Straight ahead on "Our World" ... Recommended new rules for ethical stem cell research ... the U.S. government's new healthy-eating guide ... and challenges to America's science competitiveness

GATES: "The whole idea of the H-1B visa thing is, don't let too many smart people come into the country. The thing basically doesn't make sense."

Those stories, new Macintosh and Windows updates, and "smart plastics."  I'm Art Chimes.  Welcome to VOA's science and technology magazine, "Our World."

A couple of promising studies on Alzheimer's Disease were published this week.

One suggests that gene therapy may be useful as a treatment for Alzheimer's, a dementia condition that is common among people in their 80s, and that's become a major health concern as people live longer.

In the study, which was reported in the journal "Nature Medicine," genes taken from the patients' skin cells were genetically modified to produce nerve growth factor, and the modified cells were implanted in the brain. The researchers then tested the patient's memory and other brain functions over the next two years and found that their cognitive decline had slowed. In one case they actually found evidence of growth of new brain tissue. With only eight people in the study, it's hardly conclusive, but it does suggest that gene therapy could be a promising treatment where ordinary medicines have so far not been very effective.

And another study reported this week -- this one using laboratory mice -- suggests that simple exercise may help keep the brain healthy. Using mice containing a gene for an Alzheimer's-like disease, researchers found that mice who used their running wheels were less likely to have amyloid plaques in their brains. Amalyoid plaques in the human brain are associated with Alzheimer's. It's not at all clear that exercise alone would prevent, let alone cure Alzheimer's in humans, but the study, published in the "Journal of Neuroscience," is intriguing and could spark more research. In any event, exercise has plenty of other benefits.

Meanwhile, a report issued this week by an independent group of U.S. scientists recommends the establishment of uniform standards for human embryonic stem cell research. The group is calling on institutions to follow the guidelines to make sure sensitive research is carried out in an ethical manner.  But as VOA's Jessica Berman reports some critics think the guidelines don't go far enough.

BERMAN:  A patchwork of regulations now governs research on human embryos for the purpose of finding cures for diseases.  Embryos are a rich source of stem cells, which scientists believe can be manipulated to grow into healthy organs.

Though there are no limits on private research on stem cells, under the Bush administration, federal funding for stem cell research is available only to those scientists who agree to work on designated embryos and embryonic cell clusters. 

Many scientists say the available cell lines are inadequate and the federal regulations too restrictive, and they have sought private funding. Researchers complain that they have had to compete for too few dollars.

Cancer researcher Richard Hynes  of the Massachusetts Institute of Technology says all this has left the public confused about the status of therapeutic stem cell research.

HYNES:  "There's concern by some people that things that are inappropriate or unethical might be being done.  On the other hand, there's concern by other components of the public that not enough is being done; that research is being delayed because of restrictions."

Dr. Hynes is co-chair of a series of guidelines issued by the independent Institute of Medicine. 

To re-assure the public that research is being carried out in an ethical manner, the report recommends first and foremost protecting the privacy of embryo donors.

Under the guidelines, Dr. Hynes says researchers should in no way attempt to influence people to donate their eggs that have been stored at fertilization clinics. 

HYNES:  "There should be no purchase or sale of these donated materials.  The clinics should not be paid for them.  The donors should not be paid for them.  Nobody should be paid for them.  This should not be a commercial activity."

In addition, the authors recommend the creation of oversight committees at every institution where therapeutic stem cell research is carried out.  Under the recommended guidelines, the committees should consider and sign off on each proposal for growing and using embryos for scientific research. 

Embryonic stem cells are usually harvested three to five days after an egg is fertilized but before it is viable enough to be implanted into a human womb.  Because the embryo is destroyed when the stem cell is extracted, opponents of the research say it is a form of abortion, which is why the administration is reluctant to use public funds to support it.

David Stevens is head of the Christian Medical Association.  Dr. Stevens says the Institute of Medicine's guidelines sidestep the most important issue. 

STEVENS:  "But our great concern is you're still destroying human lives.  Just because you put a nice packaging of ethical guidelines around an immoral practice, destroying one human life for the benefit of another, doesn't make it right."

Dr. Stevens believes more emphasis should be placed on research involving adult stem cells from bone marrow. 

But many observers believe human embryonic stem cells are more versatile and hold more immediate promise.

Marcia Imbrescia is a breast cancer survivor who helped draft the Institute of Medicine guidelines.  Ms. Imbrescia's teenage daughter suffers from rheumatoid arthritis, a lifelong autoimmune disease.

IMBRESCIA:  "Patients with diseases and with serious injury learn that fairly quickly that research is fairly complicated, that it take time, that it takes money.  I feel confident that these guidelines will help ensure that embryonic stem cell research will be done ethically and responsibly and will be worth the investment."

The Institute of Medicine report was funded by the National Academies of Sciences and the Elison Medical Foundation and the Greenwall Foundation, both non-profit organizations. 


The headline in the Wall Street Journal this week was shocking: "Only 3% of Americans Lead a 'Healthy' Lifestyle."  So I called up the Michigan State University epidemiologist who led the study.

REEVES:  "We defined having a healthy lifestyle as the following four characteristics: not smoking, having a healthy weight, good diet, and regular physical activity. And when we looked at the data from over 150,000 adults across the country, we found, quite startlingly, that only three percent of adults undertook all of these four healthy lifestyle characteristics."

Researcher Mathew Reeves and his colleagues found that most Americans followed at least one of the four attributes of a healthy lifestyle, but that fewer than one in 30 adhered to all four.

He says exercise, good diet, low weight, and not smoking together have tremendous health benefits.

REEVES:  "Leading a healthy lifestyle is probably the single most important thing that one can do to improve one's health. The benefits to them are extraordinary. And we have data now that shows that they live 6-10 years longer, and medical expenditures are one-half of those of the rest of the population."

The study was published this week in the journal, "Archives of Internal Medicine."

I asked Dr. Reeves about the problem frequently cited by people who want to do better, but who say they are confused by apparently conflicting advice about what to eat or how much to exercise. He said scientists have to do a better job at communicating with the public.

REEVES:  "And I think we've really got to simplify the message to people to say, ANY amount of physical activity is obviously better than none. And I can't, as a scientist, give you an exact prescription about the amount of activity you do, but you should basically get up in the morning and have an attitude that you're going to incorporate physical activity into your life on a regular basis."


For years, government officials in the United States have tried to communicate their recommendations for the most healthful diet through a graphic device called the "food pyramid."

The latest edition was unveiled this month, but as we hear from VOA's Rosanne Skirble, critics say the new recommendations are not explicit enough.

SKIRBLE:  The new food guide pyramid is based on dietary guidelines released earlier this year.  Secretary of Agriculture Mike Johanns says it represents the first major update of the graphic since the nutrition campaign was launched in 1992.  The problem with the original food guide pyramid, Secretary Johanns told reporters, was that few Americans were following its advice:

JOHANNS:  "With that in mind it became clear that we needed to do a much better job of communicating the nutritional messages so that Americans could understand how to begin making positive changes in their lifestyles.  And, of course, the science has evolved since 1992 with additional research on issues including the nutritional content of foods and food consumption patterns."

SKIRBLE:  The USDA's new pyramid design abandons the old horizontal food group bands, and replaces them with a series of vertical wedges, color-coded for each food group.  It also features a human figure walking up a set of stairs on one side of the pyramid, calling attention, for the first time, to the importance of exercise.

To take full advantage of the new graphic, consumers are directed to an interactive website called   

SKIRBLE:  The 2005 Dietary Guidelines on which the new food guide pyramid is based promote whole grains over processed grains, fruits and vegetables, low-fat meat and dairy products and less sugar.  Margot Wootan is director of nutrition policy at the Center for Science in the Public Interest, a Washington-based advocacy group.  Dr. Wootan is thrilled with the USDA's new dietary guidelines, but believes the new food pyramid confuses more than it informs.  She notes that it dodges the politically difficult message of telling people what foods they should avoid or eat less of, as for example, in the grains category:

WOOTAN:  "People should mostly choose brown rice and whole wheat bread and wheat pasta and whole rain cereal for breakfast, instead of choosing food at the tip of the pyramid like cookies and pastry and donuts.  But they don't show those foods on the pyramid.  So people don't know what that wedge shape means and in fact they might not even know that that is the grains group because it only color coded, and there are not any pictures of whole wheat bread and brown rice on the pyramid." 

SKIRBLE:  Dietary change is an urgent matter, says Doctor Wootan. Sixty-five percent of American adults are overweight or obese and face a greater risk of heart disease, diabetes and early death. Doctor Wootan says the public needs more than a graphic symbol or Internet website to promote better nutrition.

WOOTAN:  "What we really need is a national effort to try to support Americans in their efforts to eat well, be physically active and maintain a healthy weight.  You know, it is not enough to point your finger at people and say, You should eat according to the pyramid.  We need to make sure that it is possible to eat that way, that it is easy, that it is accessible and that it is affordable."

SKIRBLE:  The government is working closely with dieticians, nutritionists, educators and school groups to disseminate the dietary information.  The challenge will be to communicate the message to Americans who eat too much and don't exercise enough, and who can't surf the Internet for their own My Pyramid nutrition guide. I'm Rosanne Skirble.

For more in-depth nutrition information than you can get from a simple graphic device like the food pyramid, there's a wealth of other advice on the Internet beyond "MyPyramid-dot-gov." One of the best online sites for nutrition information that we've found is at -- that's the Food and Nutrition Information Center, a project of the U.S. National Agricultural Library.

ALESSI:  "It offers a very broad depth of information on a variety of food and nutrition topics. And all the information is reliable, it's accurate and credible, and people can trust us."

Cathy Alessi is a registered dietician who works at the Food and Nutrition Information Center. She says the site is updated constantly to ensure it reflects the latest research on human nutrition.

ALESSI:  "As you know, there's so many changes going on with scientific research, so we stay on top of the latest that's going on in research, and we make sure that the information on our website is up-to-date and current."

Some of the website's treasures are almost hidden. Click on the button labeled "Topics A to Z" for in-depth facts on some 75 different subjects, including food allergies, nutrition and cancer, pregnancy, and so on. Although the focus on Americans, there's much of interest to an international audience. Human nutrition needs are pretty standard around the world, but culture and food preferences aren't, so the site features links to global nutrition websites.

ALESSI:  "We do have international nutrition resources; that's one of our links on the 'Topics A to Z' section. And we've got very interesting things like dietary guidelines from around the world and foreign nutrition organizations, and we have that even divided by different parts of the world."

For a world of reliable nutrition information, surf on over to the Food and Nutrition Information Center at -- or get the link from our site,

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You're listening to VOA's science and technology magazine, Our World. I'm Art Chimes in Washington.

On Friday, Apple Computer released "Tiger," the latest version of its Macintosh OS-10 operating system. A key feature of the $129 upgrade is a search feature called Spotlight that will help users find information on their computer's hard disks, which are getting bigger and bigger.

Spotlight enables users to track down elusive e-mails, text documents, photos, or music files almost instantly. Wall Street Journal technology guru Walter Mossberg said it could "spark a major change in the way people use computers," and he called it "a big deal."

The new Mac release comes days after Microsoft chairman Bill Gates gave a preview of the new version of the Windows operating system, code-named Longhorn. It, too, will offer a search function, but Longhorn isn't expected to ship until the end of 2006. In the meantime, Windows users can use add-on search programs, like the popular and free Google Desktop Search.

Microsoft also says Longhorn will be the most secure version of Windows ever, answering critics who have complained for years about Windows' susceptibility to malicious software like computer viruses.


Bill Gates was among the panelists at the Library of Congress Wednesday for a discussion on innovation, competitiveness and technology. While the United States remains a science powerhouse, its relative standing has weakened as other countries, such as India and China, develop their own science base.

Education is often cited as one reason the United States isn't holding on to its lead. America's universities remain world class, but Princeton University president Shirley Tilghman says there are deep problems in the country's elementary and secondary schools.

TILGHMAN:  "Too often by the time they get to us they are math-phobic, they're science-phobic, despite the fact that I'm fully convinced [that]  many of them have the talents to become great scientists. And the consequence of this is [that] we have been increasingly dependent upon attracting students from outside the United States to American universities, where they come and they excel. They do extraordinarily well. In the past, as Bill said, many of them would stay, but increasingly they are going home (a) because there are better opportunities at home --"

And also, she said, it's because visas to study in America have been harder to get since the 2001 terrorist attacks in the United States.

For his part, Bill Gates urged lawmakers to end restrictions on H-1B visas, which allow companies like Microsoft to hire engineers and scientists from overseas.

GATES:  "The whole idea of the H-1B visa thing is, don't let too many smart people come into the country. The thing basically doesn't make sense."

Mr. Gates said he would like to see Congress eliminate the cap on H-1B visas, now set at just 65,000 foreign workers each year. Many American engineers and scientists who are worried about their jobs want the visa limit to remain.


Researchers in the United States and Germany have developed a way to create plastics in one shape that will change into another shape when exposed to light of a particular wavelength.

It sounds like magic. Think of a flower that opens and turns to face the sun. It does so in response to light. Other plastics have been developed that change shape depending on the temperature. But using light rather than temperature could give shape-changing, or so-called "smart" plastics entirely new applications.

The smart plastics team includes Robert Langer, professor of chemical and biomedical engineering at MIT, the Massachusetts Institute of Technology.

LANGER:  "We've created a series of plastics that you could put into a particular shape -- whatever shape you want -- and then you could shine a light on to it, and it will convert into a totally different shape -- again, whatever shape you might want it to be."

The trick, if we can call it that, is in the way the plastic's molecules are linked together. The shape of the material is affected by the bonds between the molecules, and Prof. Langer and his colleagues have developed bonds that are sensitive to a particular wavelength of light.

LANGER:  "So these would be sort-of what we might call molecular switches or photo-sensitive groups that are essentially grafted on this polymer network. So basically what we've done is we've now converted it into this new shape and we fixed it into that new shape by these molecular switches or bonds."

And the process is reversible.

LANGER:  "If we want to change it back to the original shape, we just shine a light at a different wavelength, and it actually cleaves those bonds, and it'll go back to the original shape."

One application for such a versatile material might be in medicine. For example, cardiologists use stents, a kind of lattice tube, to open up clogged arteries. MIT's Robert Langer says a shape-changing plastic stent might start out in collapsed form, so it can be easily inserted, then activated with light from a fiber-optic probe.

LANGER:  "What you might be able to do someday, with further work, [is] put one of these systems in, like a string, and then shine a light on it, and it converts into the stent-type structure. So it would be a much simpler, easier way to do it, much more patient-friendly."

As Professor Langer said, however, such applications are not yet possible today, but could be in the near future. He and his colleagues published their findings this month in the British journal "Nature."


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Our World is edited by Rob Sivak. Our technical director is Gary Spizler. 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 Our World.