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" ... The most Earth-like planet yet outside our Solar System ... a polio campaign in Somalia ... and growing brain cells in the laboratory ...
STEINDLER: "We can now begin to think about, how can we mobilize these very, very potent cells to be used for treating different diseases -- in this case, treating different neurological diseases? But we're not there yet."
Those stories, alternative medicine in med school, and more. ... I'm Art Chimes. Welcome to VOA's science and technology magazine, "Our World."
A team of American astronomers says they have discovered what might be the most Earth-like, rocky planet ever detected outside our solar system. Discovery of extra-solar planets, as they're called, has become almost routine over the past decade. But as VOA's David McAlary reports, this latest discovery stands apart from most of the others.
McALARY: Since 1995, planet hunters have found 155 celestial bodies in orbit around other stars in our Milky Way Galaxy. They have been getting much better at finding ever-smaller ones as telescope technology and search methods have improved. The first to be found were gas giants like Jupiter and Saturn. Last year, smaller, Neptune size planets first appeared to astronomers.
Now, the most productive of all the searchers, Geoffrey Marcy of the University of California at Berkeley and Paul Butler of the Carnegie Institution of Washington, report finding their 107th planet and the most similar yet in mass and possibly rocky composition to Earth.
MARCY: "This is truly an extraordinary announcement."
McALARY: Geoff Marcy speaks at a Washington news briefing.
MARCY: "We knew about it three years ago. We've been following it quietly, carefully guarding the secret, while we double and triple checked."
McALARY: The newly discovered planet is relatively near us, about 15 light years from Earth. It is not precisely like our home planet, but a bigger cousin, estimated to be six to eight times Earth's mass, twice the diameter, and so close to its star that it takes less than two days to orbit, making its temperatures oven-like. The star itself is only one-third the mass of our Sun.
But Mr. Marcy says it all bears a resemblance to our solar system, especially since his team had already discovered two gas giants there.
MARCY: "The whole planetary system is sort of a miniature of our solar system. The star is small, the orbits are small, and in close is the smallest of them, just as the architecture is in our own solar system, with the smallest planets orbiting inward of the giants. For the first time, we are beginning to find our planetary kin among the stars."
McALARY: Mr. Marcy and his colleagues have no proof the planet is rocky like Earth, but believe its low mass prevents it from retaining gas like Jupiter does.
The astronomers found it the same way most of the other planets outside our solar system were detected. They did not see it directly, but measured the varying intensity of the starlight, which suggests the star is wobbling because a planet's gravity is pulling on it. The new planet caused a much smaller flicker in its star than all the previous planets caused in their stars, leading the astronomers to conclude it is a smaller planet.
U.S. space agency astronomy theorist Jack Lissauer suggests astronomers will find even smaller planets as telescope technology improves to detect less conspicuous star wobbles. He points out that a U.S. planet-searching satellite to be launched in three years will use another technique that measures momentary decreases in a star's brightness, suggesting a planet is passing by.
LISSAUER: "The planet that we've announced today is probably the most Earth-like world to have been discovered since the dawn of history, but it's not likely to hold that title for very long."
McALARY: Any smaller planets could well come from the catalog of 1,500 stars astronomers Marcy and Butler are currently observing. David McAlary, VOA News, Washington.
NASA technicians moved the space shuttle Discovery back out to its launch pad on Wednesday in preparation for its next flight, possibly as soon as mid-July.
The move comes three weeks after they brought the spacecraft -- which was already on the launch pad -- back into the massive Vehicle Assembly Building. Technicians replaced the fuel tank with one equipped with heaters to protect against ice that could break off and damage the shuttle during launch.
The shuttle fleet has been grounded for more than two years, since the shuttle Columbia broke up on re-entry into the atmosphere.
This mission will bring supplies to the international space station and test out safety enhancements and procedures.
Scientists at the University of Florida have developed a technique for growing new brain cells in the laboratory.
It's apparently the first time that mature brain cells have been created in a way similar to how cells grow inside an actual brain.
The researchers were using rodent brain cells, but they say that if the process also works in humans, it holds out the prospect for using a patient's own brain cells to treat diseases such as Parkinson's or epilepsy.
STEINDLER: "We can now begin to think about, how can we mobilize these very, very potent cells to be used for treating different diseases -- in this case, treating different neurological diseases.
So scientists like us all over the world are trying to coax these cells to become ready as soon as possible for treating a variety of neurological disorders. But we're not there yet."
Dennis Steindler is the lead author of the paper describing the new technique, which was published this week in the "Proceedings of the National Academy of Sciences." Dr. Steindler runs the McKnight Brain Institute at the University of Florida, and he told me that developing this technology has been a goal of researchers for some time now.
STEINDLER: "For the last several years many groups, not just mine, have been focusing on trying to identify the so-called adult stem cell, but they've been rather elusive, and there's been a need for technology to be developed that would allow scientists and clinical investigators to begin to get a handle on how to moblize these cells to be used as potential therapeutics for neurological diseases."
Dr. Steindler says researcher Bjorn Scheffler and his colleagues were able to coax the stem cells into becoming different kinds of brain cells.
STEINDLER: "The technology described in this report has not only revealed to us what we believe to be the stem cells from the adult brain, but also by doing this study and watching this cell do its magic under what is referred to as a live cell microscope, we have been able to control its behavior, and that's rather unprecedented... to be able to generate a large number of the types of cells that we would like to make lots of for fixing broken brains. And those cells are called neurons."
Regenerative scientists use the term "potency" to describe the ability of one cell to become another type of cell. Embryonic stem cells, for example, are considered pleuri-potent. They can grow into many other types of cells.
STEINDLER: "The type of cell we're talking about here is referred to as multi-potent. And that is, it gives rise to a lot of different cells. In this case we have watched it before our eyes make the three types of cells that populate the brain -- neuron, astrocyte and oligodendrocyte. We can actually watch them go from a stem or progenitor cell all the way to a fully-developed cell."
When he talks about watching the cell change, he means that literally. Part of their technique involves using a special microscope that allows the scientists to actually view the changes that the cell undergoes.
Dr. Steindler says it's unclear whether these brain stem cells might be coaxed into creating other, completely different kinds of cells that would be found elsewhere in the body -- it's not something his lab has tried, but he says it might be do-able.
STEINDLER: "We have not challenged it to try to make other cells and tissues. And based on publications from others in the past, it's not impossible to try to pull that off."
This latest research seems certain to add fuel to the ongoing debate in the United States about the use of embryonic stem cells. Rules imposed by the Bush administration have put limits on their use for research, even though many scientists believe they have the most promise for being able to cure disease. Opponents of the research usually cite ethical objections to the source of cells. They come from embryos, which are destroyed in the process of extracting the cells. They also say the most promising research advances have involved adult stem cells. But supporters of mbryonic stem cell research say there have been too many restrictions for scientists to produce much evidence of the value of the embryonic cells.
The World Health Organization is embarking on a 10-day campaign in Somalia to immunize children against polio. There are no reported polio cases in Somalia, and the WHO wants to keep it that way, so they plan to vaccinate all of the country's 1.2 million children under age five.
The battle against polio suffered a setback two years ago, when vaccinations were suspended in northern Nigeria amid charges that the vaccine was contaminated and caused infertility. That allowed the disease to gain a foothold elsewhere in Africa, including Ethiopia and Yemen, on Somalia's borders.
Despite the setback, the head of WHO's Global Polio Eradication Campaign, David Heymann, says the goal of eradicating polio remains reach-able.
HEYMANN: "[It's] very sad that this setback has occurred because this means that more children are being paralyzed throughout the world, and our goal is to stop children from being paralyzed. ... The countries to which polio has spread recently, these 16 countries, have all interrupted its transmission before and there is no reason they can't do it again.
Dr. Heymann says Africa may miss its target of being polio-free by the end of this year. The battle against the crippling disease is, however, being won in Asia, and he says he believes that India, Pakistan and Afghanistan will be polio-free within six months or so.
Dr. Heymann says more money is needed -- $50 million for the rest of this year, plus another $200 million for 2006 -- to ensure the success of the fight against polio.
In 1883, the eruption of the Krakatoa volcano in Indonesia killed 40,000 people, and the blast was heard some 5,000 kilometers away.
Volcanoes are a sometimes-destructive window on the planetary forces that created our world, and remain at work inside our living planet. Want to learn more? Follow that lava to our Website of the Week, Volcano World, at volcano.und.edu
De SILVA: "It's a resource basically to find information about volcanoes, and our primary purpose is to make sure that current activity is catalogued, and then we've managed to build a portfolio of pages, which cover virtually every aspect of volcanism."
Shan [Shanaka] de Silva heads the department of Space Studies at the University of North Dakota, where Volcano World is based.
The site features basic information about volcano science, adventure-filled virtual visits to volcano sites, and videos of recent eruptions. And there's a catalogue of active and dormant volcanoes, with an interactive map to help you find one nearby.
DE SILVA: "If there has been a volcano that has been active in the last 200 years or so, that volcano is available. And sometimes we go back 10,000 years. So we essentially mimic the catalogue of active volcanoes -- including volcanoes on other planets as well."
Although there's something on Volcano World for anyone with an interest in volcanoes, Professor de Silva says a lot of their users are schoolkids and older students.
DE SILVA: "We get a lot of requests, you know, class projects, and they want information ranging from 'answer 10 questions about volcanoes,' activity at certain classic volcanoes: everybody's heard of Hawaii or Mt. Saint Helens. When Mt. Saint Helens was recently active and during the current activity, we had something like 300,000 hits a day on that, and a lot of of that was from schools."
And there are also lesson guides and other useful tools for teachers who are planning classes about volcanoes.
There are plenty of pictures on Volcano World, but the presentation is not fancy, so this site works very nicely on a dial-up modem, which we like. Point your browser to volcano.und.edu, or get the link from our site - voanews.com/ourworld.
MUSIC : "Volcano" (Presidents of the United States of America)
It's VOA's science and technology magazine, Our World. I'm Art Chimes in Washington.
One of this country's top climate experts says global warming is already having an impact on the most dangerous and destructive storms, with hurricane intensity increasing along with temperatures.
A senior scientist at the National Center for Atmospheric Research, Kevin Trenberth, writes in the journal "Science" this week that the trend in hurricanes is toward more extreme storms, with more rain and wind.
TRENBERTH: "Heavy precipitation, which is the top five percent in terms of the amount in each day, that was up 14 percent last century, and the very heavy events, which is the top one percent, was up 20 percent last century, so when we get rains these days, the evidence suggests that it rains harder than it used to, you know, 30 or 40 years ago, and what used to be a one in a 100 year storm is now a one in a 30 or one in 50 year storm."
Hurricanes are powered by heat, which is why they form in the tropics. As atmospheric temperatures rise, the ocean heats up. More water evaporates from the ocean surface, and the warmer air can hold more water vapor.
TRENBERTH: "For every one degree Celsius rise in temperature, the water-holding capacity of the atmosphere increases about seven percent. And this provides fuel for all kinds of weather systems."
The result of this process can be seen in the correlation between higher temperatures and more active hurricane seasons.
TRENBERTH: "When we look around the world we find that the most active year on record seems to be 1997. 1997 was the time when we had this major el Niño, the 1997-1998 el Niño event, and 1998 is still the warmest year on record. And so the most active hurricane season and the warmest year on record sort of go hand-in-hand.
While some politicians remain skeptical about global warming and its causes, Dr. Trenberth, who heads the Climate Analysis Section at the National Center for Atmospheric Research, agrees with most other scientist who have studied the matter.
TRENBERTH: "Global warming is happening. This has been, I think, very well established. The global mean temperature is probably outside of the realm of natural variability somewhere around about 20 years ago, in terms of the warming. And we've been able to establish that that is due to the increases in carbon dioxide and other greenhouse gases in the atmosphere. And so it's human related."
Although global warming as a result of human activity is increasing the severity of hurricanes, Dr. Trenberth says there is no evidence that higher temperatures affect the number of hurricanes, or their paths, or how many hit land.
Herbal medicine, acupuncture, and massage therapy: there was a time not too long ago when these things were dismissed by American medical professionals as charlatanism. Today, though, more and more U.S. medical schools are incorporating so-called complementary alternative medicine into their curricula, and as VOA's Maura Farrelly reports from New York, the trend is being praised by some… and criticized by others.
FARRELLY: It's a Wednesday evening in an auditorium at Columbia University Medical Center. More than 100 physicians from around the country have gathered for a five-day continuing education conference.
CONFERENCE: "Are there any specific questions about patients with HIV disease before we sort of wind up here ... "
FARRELLY: Participants at this workshop are discussing whether it is useful to give HIV patients dried Echinacea-a flower that's indigenous to North America and is believed by many to stimulate the immune system.
CONFERENCE: "We have two clinical trials on HIV with Echinace... with an antiviral agent, so I mean, the patient was on medication. But it actually showed that those patients fared better ... "
FARRELLY: For the last ten years, Columbia has been hosting this annual conference on Botanical Medicine in Modern Clinical Practice. It's organized by the university's Richard and Hinda Rosenthal Center for Complementary and Alternative Medicine. Founded in 1993, the center was among the first of its kind at a major American medical school. Dr. Fredi Kronenberg is the director.
KRONENBERG: "The dean at the time at Columbia was a psychiatrist by training and had seen how psychiatry had gone from sort of being on the outside, wasn't really considered 'real medicine,' to [being an accepted discipline. He felt] that complementary medicine was kind of following a similar pathway. And [he] really believed that these things should be studied and should be studied at a place like Columbia."
FARRELLY: Today, 95 U.S. medical schools, out of a total of 125, offer coursework in complementary alternative medicine. In most cases, the information is incorporated into classes that focus on more more widely-used western methods, but Fredi Kronenberg says it's important for doctors to be familiar with non-western approaches to health and healing, as well.
KRONENBERG: "Most consumers are using these things based on their own experience, word-of-mouth, their friends' experience. Many people would like to talk to their doctors about this, and have their doctors be conversant, at least, so that they can know whether this might truly complement what their physicians are doing. Or maybe it would interact negatively with a drug they're being given."
FARRELLY: The popularity of treatments like herbal supplements and massage therapy has skyrocketed in recent years. A 2002 survey by the National Institutes of Health found that as many as a third of all American adults have tried some kind of alternative therapy. And the U.S. Congress has given the NIH an annual budget of more than 100 million dollars to study the safety and efficacy of these therapies, ranging from acupuncture to spirituality. But it's a waste of money, according to critics like Robert Baratz, a physician who heads the National Council Against Health Fraud.
BARATZ: "This is taxpayer money for what? Studies of remote prayer, to see if people praying in one city can affect the outcome of disease in another city. There is no such thing as complementary and alternative medicine. It is a marketing term that has been coined by essentially those who are promoting what used to be called snake oil."
FARRELLY: Dr. Baratz points to the case of Megan Wilson, a 16-year-old girl who recently died of an asthma attack while under the care of a so-called naturopathic physician. Naturopathy uses herbal remedies, rather than prescription drugs like the ones that probably could have saved Megan's life.
Fredi Kronenberg of Columbia University acknowledges that there have been a lot of mistakes -- and even fraud -- in the field of alternative medicine. But she says that's why it's important for medical schools to study alternative methods and push for professional standards. And Dr. Kronenberg denies that centers like the one she directs are promoting health fraud or … in Robert Baratz's words … "snake oil."
KRONENBERG: "If we're promoting anything here at Columbia, we're promoting the rigorous scientific evaluation of various complementary therapies. We're trying to promote and advocate for the government to regulate herbal products better, so that they're better quality, so we can tease out… what if this doesn't work because it's a bad product? Versus what doesn't work [simply] because it doesn't work?"
FARRELLY: And the government can't adequately regulate the alternative medicine industry, Dr. Kronenberg says, without the appropriate research. I'm Maura Farrelly.
MUSIC: Our World theme
That's our show for this week. Got a science question? If we answer it on the show we'll send you a special VOA gift as our way of saying thanks. Email us at email@example.com. Or the postal address is -
Voice of America
Washington, DC 20237 USA.
Our World is edited this week by Faith Lapidus. Our technical director is Gary Spiezler. 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.