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MUSIC: "Our World" theme
Straight ahead on "Our World," Experts say climate change will threaten the food supply ... changing one type of blood into another ... and the strange case of the disappearing honeybees.
VanENGELSDORP: "there are crops that are 90–100 percent reliant on honeybees for pollination. You need bees for apples. And if you don't have bees you don't have apples."
Those stories, a taste of the science of taste, and more. I'm Art Chimes. Welcome to VOA's science and technology magazine, "Our World."
International climate change experts Friday said global warming is on track to affect human health and the food supply, as well as natural systems ranging from wetlands to coral reefs.
Release of the U.N.'s Intergovernmental Panel on Climate Change report followed last-minute wrangling between scientists and policymakers over how to describe the degree of certainty of their projections.
In the end, government officials seeking consensus managed to slightly weaken the scientists' conclusion that the risk is very high, but the report leaves no doubt about the seriousness of the threat.
Co-chairman Martin Parry said scientists no longer are relying on computer projections. On every continent, he said, there is actual evidence that rising temperatures are affecting plants, glaciers and other ecosystems.
Climate change will also directly affect people, particularly those in the tropics, where Parry said declining rainfall will affect agricultural production —
PARRY: "Because any amount of warming is going to decrease yields. That is exactly what we don't want, isn't it. We've got 500 million hungry people in the world today, according to the FAO. Those numbers are likely to increase as a result of climate change."
Parts of Asia will face more flooding as glaciers melt, and almost one-third of all species could face an increased risk of extinction if temperatures rise just two degrees.
IPCC chairman Rajendra Pachauri said not everyone will feel the pain equally.
PACHAURI: "It's the poorest of the poor in the world, and this includes poor people even in prosperous societies, who are going to be the worst hit."
This is the second of three working group reports on climate change being issued by the IPCC. The first report, released in February, confirmed that global warming is here and is caused in part by human activity. The next report, due in May, will describe ways that governments can respond to climate change.
Medieval alchemists tried to turn lead into gold. Modern scientists are onto something that seems equally outlandish. As we hear from Faith Lapidus, a team of hemo-alchemists have in fact figured out how to change human blood from type A or type B to the universal-donor type, type O.
LAPIDUS: A- and B-type blood cells have identifying sugar molecules on them. A team led by Dr. Henrik Clausen, of Harvard University and the University of Copenhagen, isolated enzymes that trim off those molecules.
CLAUSEN: "They can clip off very specifically, just that one sugar residue. And what's below or beneath in this long sugar chain is really the same or very similar to what is on blood group O red cells. So it's sort of a scissor trimming of the red cell surface so the immunogenic sugars are removed, the ones you don't have."
LAPIDUS: That prevents an immune reaction against the wrong blood type.
Clausen explains that donated blood would be mixed with the enzyme, and shaken for an hour.
CLAUSEN: "And then you basically wash the red cells [so] the sugar you clipped off washes off, and the enzyme you put in washes out as well, and once you wash the cells, you put them back into the storage solution, and you don't have to match for A/B or O. You can use it universally."
LAPIDUS: If the process is found to be safe and effective on a large scale, it will make a small but important difference in the blood supply, according to Dr. Richard Benjamin, chief medical officer at the American Red Cross.
BENJAMIN: "This product will provide us with more group O blood, but this is not a panacea. We still need the donors to come in!"
LAPIDUS: Details of the newly isolated enzymes appear in the current issue of the journal Nature Biotechnology. I'm Faith Lapidus.
A study in Tanzania shows that pregnant women in developing countries have healthier babies if they are given a simple, cheap medical intervention — vitamin supplements. In a world where an estimated 20 million infants are born too small each year, the researchers recommend vitamin pills for all expectant mothers in poor countries. VOA's David McAlary reports.
McALARY: The World Health Organization says more than 15 percent of all babies are delivered underweight, less than 2,500 grams. Ninety-five percent of these births occur in developing countries.
Harvard University School of Public Health researcher Wafaie Fawzi says low birth weight can have serious health consequences for an infant.
FAWZI: "Low birth weight is associated with adverse outcomes during infancy, including infant mortality and poor growth and cognitive development. So reducing low birth weight could have a beneficial effect on those end points later in life."
McALARY: Fawzi and colleagues from Harvard and the Muhimbili College of Health Sciences in Dar Es Salaam, Tanzania, have found that multi-vitamin supplements can be a way of doing that.
To find out how beneficial they are, they gave vitamins to 4,200 pregnant Tanzanian women.
FAWZI: "Giving those supplements reduced the risks of low birth weight and having a small baby at birth compared to women who did not receive the supplements."
McALARY: The risks were about 20 percent less if the mothers took the vitamins.
The daily supplements contained all the B vitamins, vitamins C and E, plus iron and folate in levels several times higher than recommended for women in industrial nations.
The doctors report in The New England Journal of Medicine that the micro-nutrients help improve fetal growth probably by improving maternal immunity and levels of hemoglobin, the pigment in red blood cells that carries oxygen.
The researchers earlier found the same multi-vitamin regimen caused even better results among pregnant Tanzanian mothers who had HIV.
Fawzi, a native of Sudan, says multivitamins should be considered for all pregnant women in developing countries, given their potential benefits and low cost.
FAWZI: "Miciro-nutrient deficiencies are common in many developing countries. Despite having iron and folate as part of standard care in Tanzania and many of these settings, it is evident that many of these women suffer from other nutritional deficiencies besides iron and folate. So providing a supplement that includes these vitamins could have beneficial effects in those settings as well."
McALARY: In 2002, the U.N. Special Session on Children adopted a goal of reducing the incidence of low birth weight by at least one-third through 2010. David McAlary, VOA News, Washington.
Former U.S. public health officials this week stressed the importance of political independence, saying that America's credibility in the global health arena will depend on keeping politics out of the science.
The comments came as five former directors of the U.S. Centers for Disease Control and Prevention gathered at George Washington University on Wednesday to mark Public Health Week.
Jeffrey Koplan, who was CDC director under President Clinton, warned that political involvement in the science of public health undermines the effectiveness of the agency, especially in its international programs.
KOPLAN : "The closer it is identified with the political process, the harder it is to establish CDC as a non-political health agency with worldwide interests. And some of that high stature that we've all enjoyed has been eroded a bit. And it serves the political self-interests of this country best when CDC's at that distance."
For example, Koplan said, with politics out of the picture, national health agencies can talk and share scientific information at a time when politicians or diplomats might not be able to.
That can be vital when tracking the spread of epidemic disease, said James Mason, CDC director under President Reagan. He said that's because many of today's disease threats are really global problems.
MASON: "You can illustrate this very easily with avian influenza. It won't just affect one country, it'll affect all countries if this mutates."
Public health agencies like the Centers for Disease Control have traditionally focused on infectious diseases. Increasingly, though, the focus is broadening to include chronic diseases.
In some cases, elements of a Western lifestyle can have an impact on health, said David Satcher, CDC director under President Clinton. He recalled visits to China, a few years apart. In the mid 1990s, he saw streets full of bicycles and older people doing Tai Chi. A few years later he returned, and found more people driving, and changes in the traditional diet.
SATCHER: "So this obesity epidemic, which is now a pandemic, is a major threat to global health. When it comes to chronic diseases, we don't have a real strategy for dealing with that - not in our country, and certainly not in most other countries."
Satcher's observations echo a Chinese government report that found obesity doubled in the decade from 1992 to 2002.
Time again for our Website of the Week, where we showcase interesting and innovative online destinations.
This week, return with us to the thrilling days of ancient Babylon and 19th century Polynesia, and explore life today in the Amazon rainforest and modern Mongolia.
SABLOFF: "The University of Pennsylvania Museum's website is really a natural outcropping of our mission. First is archaeological and anthropological research around the world. Secondly, our collections, which number more than a million objects that have been collected over a 120-year history of the museum. And finally, public education."
Jerry Sabloff is interim director of the University of Pennsylvania Museum of Archaeology and Anthropology, online at www.museum.upenn.edu.
The Penn Museum website offers dozens of online exhibits, mostly based on shows they do at their physical museum in Philadelphia. You can explore the culture and economy of Sierra Leone in the 1930s or get recipes to prepare a meal like the one served at King Midas's funeral feast. You can learn about home life in ancient Greece, or see what their athletes were up to.
SABLOFF: "We have an ancient Olympics virtual exhibit, and this provides a wonderful history of the Olympics, some of the stories that come from antiquity, along with a variety of images relating to the ancient Olympics."
You can also read how archaeologists working in the field investigated thousands of years of trade and life around the Black Sea. And there's even an exhibit showcasing almost 3,000 years of piercing, tattooing and other body mods.
Jerry Sabloff stresses that the Penn Museum focuses on more than just the beauty or characteristics of the individual items that it displays.
SABLOFF: "The bulk of our collection comes from our own research, so it has context. These are not seen as just individual art objects. We're always trying to understand how an artifact or an object can tell us about the peoples who made it and used it. And I think our virtual exhibits — that's one of the great themes that unites all of them."
You don't have to be an archaeologist or anthropologist to enjoy the Penn Museum website, just curious about different cultures of the present and the past at www.museum.upenn.edu, or get the link from our site, voanews.com/ourworld.
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You're listening to VOA's carefully excavated science and technology magazine, Our World. I'm Art Chimes in Washington.
Millions of honeybees across the United States and other countries are dying mysteriously. Entire hives or colonies of bees are affected. And scientists are scrambling to find out why. It's not just an academic question, but also an economic one. As Bob Allen reports, bees are a critical part of global agriculture.
ALLEN: That fresh, crisp apple you bite into for lunch comes from a bee pollinating an apple blossom, but honeybees in the U.S. are under tremendous stress. A new threat is devastating them. It can wipe out entire colonies.
There's plenty of honey still left in the hives to feed the bees, but the bees have vanished. Scientists are baffled. They're calling it "Colony Collapse Disorder."
Dennis van Englesdorp is bee inspector for the state of Pennsylvania. He says the disorder first showed up in his state last fall. But it's now threatening the entire beekeeping industry:
VanENGLESDORP: "We could not sustain the level of loss we're seeing this year several years in a row. And there are crops that are 90–100 percent reliant on honeybees for pollination. You need bees for apples. And if you don't have bees you don't have apples."
ALLEN: A research team at Penn State University has given themselves until fall to come up with some answers.
On a hilly farm in northern Michigan, Julius Kolarik raises apples, cherries and honeybees.
KOLARIK: "Makes you feel good when you see bees flying."
This is the first time Kolarik has checked his bee yard since fall.
KOLARIK: "We can see that they're alive and that's the main thing."
ALLEN: It used to be considered an embarrassment if a beekeeper lost more than 10% or so of his bees annually, but things have gotten a lot tougher in recent years.
Parasitic mites have infested honeybees just about everywhere. They've weakened the bees and left them vulnerable to diseases and that's meant annual losses double what they used to be.
Now on top of that, there's this new disorder. Bee researchers say previous outbreaks of colony collapse were isolated incidents. This time it's spread across the country.
Tom McCormick's small beekeeping operation supplies honey to local markets in western Pennsylvania. That is, it did until two years ago. That's when he says collapsing disorder killed half his colonies, so he bought more bees to replace them. They did OK last year, but this spring he's looking at an 80 percent loss:
ALLEN: McCormick says two of his beekeeping friends have been totally wiped out. And they've been seeing more than one thing going on in their hives:
McCORMICK: "One, we see hives full of honey and no bees. We see other situations where we have a nice large cluster of bees with honey all surrounding them and the bees dead."
ALLEN: When he reported this two years ago, he says, state officials ignored him. Pennsylvania state beekeeper Dennis vanEnglesdorp admits he thought McCormick had a serious mite problem at first.
But now researchers at Penn State are checking other possible environmental stresses that could be killing honeybees. van Englesdorp says pinpointing the cause can be just as difficult with bees as it is with humans.
VanENGLESDORP: "You can get a heart attack if you don't eat well, if you drink too much, if you smoke, you're genetically disposed to a heart attack. It could be one of those factors. It could be a lot of those factors combining together."
ALLEN: For this year, he says, the disorder means the number of honeybee colonies will be lower, but he expects there to be enough to meet pollination demands.
For The Environment Report, I'm Bob Allen.
The Environment Report is a production of Michigan Radio. Support comes from the Joyce Foundation, the George Gund Foundation, and the USDA. Send them your comments — feedback@environment report dot org.
Finally today: When it comes to how things taste, everybody has an opinion. Some are very personal, and others are wired into the body's chemical receptors and neurotransmitters. These "hard-wired systems" are providing clues about how to make some things taste better, and maybe even fight disease. It all begins with our taste buds. From Colorado, Shelley Schlender reports.
KIDS: "Ahhhh-ahhh. Little tiny bumps. You can't see them."
SCHLENDER: That's the sound of students at the Watershed School in Boulder, Colorado getting ready to see their taste buds. Taste bud clusters show up the best if you put a drop of blue food coloring on your tongue. Zoe bravely volunteers.
KIDS: "Ooo, you look like Frankenstein."
ZOE: "Food dye does not taste good plain."
SCHLENDER: It's easy to make food dye taste better-mix it with a bowl of sugary icing. But according to Steven Leeder, it's not always that simple.
LEEDER: "A lot of medications have to be prepared in a liquid oral presentation and that requires bitter tastes to be masked."
Leeder is a doctor at Children's Mercy Hospital in Kansas City. He recently led a symposium in San Francisco at the annual meeting of the American Association for the Advancement of Science, the AAAS. During the symposium, taste experts reviewed a variety of discoveries about how we taste, why we taste, and how we might use this knowledge to improve health. For instance, Leeder says, before he gives a child bitter medicine, he uses a new compound that blocks bitter taste receptors.
LEEDER: "The ones we've used to mask medication for kids, Bitter Blocker is actually the name of it."
One of the scientists involved in creating Bitter Blocker, is Robert Margolskee of New York's Mount Sinai School of Medicine. He says that the power of taste goes well beyond how the taste buds on our tongues help kids know what's sour or sweet.
KIDS: "I like chocolate ... peaches ... jawbreakers. I like jellybeans."
MARGOLSKEE: "It turns out that there are also taste cells in the gut itself, and we have just started to probe their role in physiological responses, relevant to digestion, eating and appetite."
SCHLENDER: For decades, scientists suspected that out digestive tract includes taste-like receptors. That's because when healthy people swallow something sweet, their insulin levels rise more strongly than if the sugar is injected into their blood.
MARGOLSKEE: "Orally administered glucose — in contrast to IV injected glucose to reach the same final blood levels of glucose — is much more efficient at stimulating plasma insulin levels."
SCHLENDER: And if you pump a sugary substance directly into someone's stomach through a feeding tube, insulin levels still rise more quickly than when sugar's injected into their blood. The difference is known as the incretin effect. Margolskee says learning more may give scientists clues about how to treat diabetes.
Scientists are also learning new answers to a question often asked by children:
NATHAN: "How come all the healthy foods in the world taste horrible. Broccoli is healthy, and everyone hates broccoli!"
TEXT: It turns out, some people are born thinking broccoli's bitter. One reason is taste preferences governed by our DNA, according to David Goldstein of Duke University.
GOLDSTEIN: "Probably one of the great selection pressures that differed amongst human populations would be those selection pressures associated with diet, because clearly diet has varied dramatically in different regions and at different time points in our history."
SCHLENDER: Goldstein's been studying the genetic variations in people's sensitivity to bitter tastes. Being sensitive is important, because poisonous plants often taste bitter. But most populations include many people who are not sensitive to bitter tastes. Perhaps that's because some bitter foods, like broccoli, are still nutritious.
But Goldstein suggests another reason … possibly, eating bitter foods that contain small amounts of the deadly poison cyanide might interfere with malaria. Bitter almonds and cassava are two edible foods that contain cyanide.
GOLDSTEIN: "A possible explanation, and it is really only possible, but a possible explanation, is that increased exposure to some of these somewhat toxic compounds could in some way be protective against malaria."
SCHLENDER: To go beyond speculation, Goldstein says more research should be done. But it might be yet another way that understanding taste can lead to better treatments for disease and solve mysteries about how and why, we taste. For Our World, I'm Shelley Schlender in Boulder, Colorado.
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Our World is in its eighth year, but this show is my third anniversary as host, and so I want to thank you for listening. 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.