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MUSIC: Our World theme
Straight ahead on "Our World" ... A new way to get stem cells ... severe weather and climate change... and a fertility test for men who smoke
BURKMAN: "The people who are very heavy smokers — number of cigarettes per day: 20, 30 — almost all of them failed our test."
Those stories, oxygen on the moon, recipes on our Website of the Week, and more... I'm Art Chimes. Welcome to VOA's science and technology magazine, "Our World."
This week, U.S. scientists reported success at generating embryonic stem cells in a way that may ease ethical concerns, and could provide promising new treatments for a variety of diseases.
Stem cells have the potential to develop into many different cell types, making them a kind of repair system for the body. Embryonic stem cells, of course, come from embryos. The usual method of extracting the stem cells destroys the embryo, raising ethical questions. For that reason, the Bush administration has imposed severe limits on stem cell research.
But biotechnology company Advanced Cell Research, based near Boston, says it has adapted a method widely used in fertility, or IVF, clinics to extract stem cells.
LANZA: "We used a biopsy procedure that is carried out in IVF clinics throughout the world. The procedure known as PGD is relatively simple and does not injure the embryo. In fact, it's been used to generate hundreds of healthy babies."
Company medical director Robert Lanza says a single cell is removed from a newly-fertilized embryo, which then develops normally. They have been working with laboratory mice, not humans, and he says they have had good success so far.
LANZA: "We generated a dozen stem cell lines. The cells were genetically normal and able to generate all of the cell types in the body, including nerve cells, bone, and even beating heart cells."
Dr. Lanza says that the research, which was published online by the journal Nature, shows enormous potential if the procedure can be extended to humans.
LANZA: "The field of stem cell research has been crippled by the lack of accessible, quality stem cell lines, and there are only a handful of approved lines, all of which are potentially contaminated with animal pathogens. Others are sickly, they're difficult to grow, and have started to display genetic abnormalities. And the use of these lines in clinical trials could lead to serious health risks."
Because embryonic stem cells can be directed to replace damaged or diseased cells in a variety of vital organs, they could have enormous theraputic potential and may one day be used to treat Alzheimer's Disease, diabetes, spinal cord injury and other conditions.
This week, hurricane Wilma wound its way through the Caribbean, battering island nations and the Yucatan peninsula and threatening Florida. At one point, Wilma was the most powerful storm ever recorded in the region. It was a dramatic backdrop for a new study, published this week by the U.S. National Academy of Science, that predicts extreme weather events such as floods and droughts are likely to increase in the United States. As VOA's Rosanne Skirble reports, the forecast suggests these events could be large enough to disrupt the country's economy and infrastructure.
SKIRBLE: The climate model run on computers at Purdue University analyzed weather patterns for different regions across the country. The projections are not about specific events. But the study's author, Purdue assistant professor of earth and atmospheric science Noah Diffenbaugh, says the projections do create a remarkably detailed picture of the kind of weather Americans can expect in the years ahead:
DIFFENBAUGH: The desert southwest shows the largest increases by the end of the 21st century. In those areas we are looking at what is now the hottest two, two and one half weeks of the year to last for up to three months.
SKIRBLE: The model also forecasts warmer winter days.
DIFFENBAUGH: So, if you imagine the coldest two to two and one half weeks of the year in the northeast the temperatures that are reached at present during the coldest weeks of the year are reached very rarely by the end of the 21st century. In fact the coldest temperatures that are reached at the end of the 21st century will be up to 10 degrees centigrade warmer than they are now.
SKIRBLE: The climate model analyzed hundreds of dynamic environmental factors from ocean currents, cloud formations and vegetation cover to atmospheric heat-trapping greenhouse gases.
Researchers first did a test run of the climate model, looking back in time between 1961-1985. The results fairly accurately matched what actually happened during those years.
Then the model worked non-stop for five months to chart the future trends. Noah Diffenbaugh says improvements over prior climate models allowed the team to look at smaller plots of land at higher resolution than ever before.
DIFFENBAUGH: The state of the science was 50 kilometer resolution and what we have done is 25 kilometer resolution. So, we have greater spatial detail and we have more reliable statistics.
SKIRBLE: The model assumes that heat trapping carbon dioxide will double over the century if current trends continue, a scenario also described by the Intergovernmental Panel on Climate Change, a group charged by the United Nations to assess the impacts of global warming.
Noah Diffenbaugh says that could mean major disruptions in everything from water and energy supply to public health threats like West Nile virus.
DIFFENBAUGH: West Nile virus is limited in the winter by extreme cold temperatures. So [warming temperatures] could be a release of that cold limitation. But at the same time the vectors that spread West Nile are also sensitive to extreme precipitation and to extreme heat. So we don't know how those three factors will interact.
SKIRBLE: Mr. Diffenbaugh says while the climate model is not perfect, it is a vehicle to begin discussion about the future consequences of climate change. He says the research tool is being used to study many regions of the world and for the first time includes a growing number of scientists from developing countries. I'm Rosanne Skirble
The Hubble Space Telescope has been providing astronomers with views of deep space for years.
Now, scientists have turned the orbiting observatory on our nearest neighbor. The new images have identified minerals on the Moon that could provide oxygen to future astronauts. Hubble program scientist Jennifer Wiseman spoke to reporters at a news conference in Washington.
WISEMAN: "By looking at different regions of soil on the lunar surface and comparing the reflectance of the soil in ultraviolet light, we can characterize the nature of the soil and we can even gauge the abundance and distribution of oxygen-bearing minerals in the soil.
The high-resolution, ultraviolet Hubble images show mineral variations in several different areas of the lunar surface, including sites visited by Apollo astronauts in the early 1970s.
The scientists say they detected quantities of ilmenite, a mineral that contains oxygen. Minerals with oxygen are not at all unusual on the moon, but Northwestern University planetary geologist Mark Robinson says ilmenite stands out.
ROBINSON: "Ilmenite is special in the sense that it's relatively easy to break it apart to get to the oxygen. And so if you have oxygen, depending on the process you're using, one of the processes, when you reduce this ilmenite mineral, you make water. And of course that has very obvious uses for human consumption. And then you can further break down that water into hydrogen and oxygen. And you can use hydrogen and oxygen later to power a fuel cell to make electricity to make rocket fuel to power rockets."
To verify their conclusions, the scientists compared data from the telescope with rock samples gathered by astronauts from the same part of the moon. That "ground truth," as scientists call it, confirmed the accuracy of the Hubble data. Jim Garvin, chief scientist at NASA's Goddard Space Flight Center, explained.
GARVIN: So we have good data, and that's ground truth. That's the kind of ground truth we use in remote sensing. Those materials we've measured in labs using varieties of methods. So we had that ground truth. Now in Aristarchus, no human or robot's ever been there. So when we look at that site, leveraging against what we know at [the] Apollo 17 [landing site], we're trying to see precisely, with much greater precision than we can say today, how much of this kind of resource and other things are there."
The Aristarchus plateau is a lunar feature of great interest to geologists that has not been visited by astronauts.
NASA official Michael Wargo said the techniques unveiled by these latest findings from the Hubble Space Telescope serve science ... as well as future moon missions.
WARGO: "The results are going to help us answer key questions when it comes to the moon — questions about the physics and the chemistry of the moon, and about its evolution. But it's also going to be important to us as we plan to go back to the moon.
The space agency last month announced an ambitious plan to replace the aging shuttle with spacecraft that could take astronauts back to the moon. But the future of the Moon plan is uncertain, with political and funding obstacles to overcome.
Time again for a listener science question. This time, our question is from Sujata Shah, in Gujarat state, India. She wants to know why planets and other objects in the solar system are ball-shaped.
For the answer we turned to the Adler Planetarium in Chicago and astronomer Mark Hammergren. I first asked him if Miss Shah's description is correct.
HAMMERGREN: "Yes, that's correct. It's an accurate description of the planets in our solar system and for large asteroids even, and for objects like the Earth's moon. We see that these planets are roughly spherical in shape. The gravity of the planets, their own gravity, tries to pull in all of the matter as close as possible to the center of the planet. And that causes the matter in the planet to reform and reshape and pull it into kind of a ball shape."
Dr. Hammergren says gravity has that effect for objects larger than about 200 kilometers across.
HAMMERGREN: "Objects smaller than that are too small to really have the gravity overcome their internal strength, the strength of the materials that make up these planets — rocks and metals. Larger than that, the internal pressures are strong enough to shatter rock and metal and re-form the planets into a sphere."
Some planets — notably Jupiter and Saturn — have a bulge at the equator. Mark Hammergren says that's due to their rapid rotation rate.
HAMMERGREN: "They spin so fast that the centrifugal force around their equators tries to throw material outwards a little bit. And that causes the stuff at their equators, which is spinning fastest, to move outwards and reshape. It pulls in at the poles a little bit, causes them to look a little squashed."
Our listener in India, Miss Shah, mentioned the Big Bang in her note, and so I asked astronomer Mark Hammergren if the massive explosion that gave birth to our universe had anything to do with the shape of the planets.
HAMMERGREN: "No, the connection is only a very remote one. The shapes of the planets owe as much to the Big Bang as we ourselves do. We are all children of the formation of the universe. That's the only connection. The physics are radically different."
Thanks to Sujata Shah for sending in an interesting question. We'll be sending her a special VOA gift as our way of saying thanks. If you have a science question, write us at ourworld@voanews.com, or listen for our postal address at the end of the show.
MUSIC: Theme from the 1960s television show, "Lost in Space"
It's VOA's science and technology magazine, Our World. I'm Art Chimes in Washington.
Pretty much everyone knows by now that smoking cigarettes is bad for you. Smoking can cause lung cancer, heart disease, and other deadly conditions. But new research presented this week suggests that if you're a man, smoking may prevent you from becoming a father.
BURKMAN: "We have very new data, using a very sophisticated fertility test, that men who are chronic smokers, on average, two-thirds of those men are losing fertility potential."
Dr. Loni Burkman led the University of Buffalo research team.
That sophisticated test she mentioned is known as the Hemizona Assay, which tests whether sperm can attach itself to the outer membrane of the egg. That attachment is necessary for fertilization, so if sperm fails to attach to the membrane, it can't go on to do the rest of the job. Dr. Burkman said her study indicates that the more cigarettes a man smokes, the less likely his sperm will attach to the egg.
BURKMAN: "The people who are very heavy smokers — number of cigarettes per day: 20, 30 — almost all of them failed our test."
Cigarette smoke is a complex cocktail of components, but Dr. Burkman said that in this case, an earlier study indicates that the culprit is nicotine.
Even the heavy smokers in this small survey maintained some fertilization capability, but Loni Burkman says smoking parents start their children off with a big genetic disadvantage.
BURKMAN: "Children of smokers are carrying the DNA of their dad. Many people have shown smoking damages sperm DNA. Smoking damages egg DNA. So the babies that come out of this process are carrying damaged DNA."
Dr. Loni Burkman of the Univeristy of Buffalo in New York state presented her research at the American Society of Reproductive Medicine meeting in Montreal. The study was funded by U.S. tobacco company Philip Morris.
Authorities in Thailand Thursday reported another death from avian flu — a 48-year-old farmer who had reportedly handled sick chickens just days earlier. It was the 13th avian flu fatality in Thailand, and the first in more than a year.
The current strain of bird flu appeared in Hong Kong eight years ago. But avian influenza has a much longer history, including the strain that mutated into the deadly 1918 human flu pandemic. VOA's David McAlary looks back.
McALARY: When birds catch the flu, it is usually a mild form that barely ruffles their feathers. But every once in a while, a virulent flu hits them, like the strain spreading worldwide that scientists call H5N1. Virulent avian flu was first recognized in Italy in 1878 and is extremely contagious among birds and rapidly fatal, with death rates approaching 100-percent.
The virulent form has been seen about 100 times since then, but it had never been linked to humans until the 1997 Hong Kong outbreak. That was the first time public health officials were aware bird flu could jump to people. The cause is believed to be contact with infected fowl.
The man who directs infectious disease research for the U.S. government is Anthony Fauci.
FAUCI: "The first H5N1 that we had experience with was in 1997 in Hong Kong. There were 18 cases and six deaths. The Hong Kong authorities appropriately culled virtually all the chickens in Hong Kong, which put a real stop to that in 1997. Unfortunately, it percolated along and came back in 2003, 2004, and 2005."
McALARY: Bird flu can spread through international trade in live poultry. Migrating birds also extend its reach, particularly water fowl.
By 2003, the H5N1 strain reappeared in South Korea, although the geographical epicenter soon became Southeast Asia, mainly Vietnam, but also Thailand, Cambodia, and Indonesia. There have been almost 120 confirmed human cases in those four countries, 60 of whom have died — a 50 percent death rate.
The disease has spread westward beyond East Asia, but it has caused no human deaths outside of Asia.
Nor have there been any confirmed cases of what health officials fear most - bird flu transmission between people. Physician Gregory Poland is a vaccine researcher at the Mayo Clinic College of Medicinel in Minnesota.
POLAND: "It now kills its primary host, the bird. It has directly infected humans. The only thing it has not yet learned to do is efficiently transfer from human to human."
The president of the vaccine division of the U.S. pharmaceutical company Merck, Adel Mahmoud, says these are ominous signals of the virus's potential to trigger a global flu outbreak.
MAHMOUD: "That is just a very, very serious warning sign that viruses are recombining, moving from avian to animals to humans and then being transmitted within the human population."
McALARY: As for the likelihood this will occur on a massive scale and begin a new pandemic, one has only to look back to 1918. That was the start of an outbreak of a very lethal flu that killed an estimated 40-60 million people worldwide within two years. Examination of the genes of stored virus samples has since shown that it, too, originated in birds and did gain the ability to jump from person to person very quickly.
If the bird flu virus adapts to human transmission and retains its virulence, experts like Gregory Poland predict that the number of deaths could be staggering. David McAlary, VOA News, Washington
If you use a personal computer, you may want to know about OpenOffice.org — which is the name of a free office suite, and also the address of the website where you can download it. Version 2 was released this week, giving users virtually all the capabilities of the popular Microsoft Office — word processor, spreadsheet, presentations — plus some things Microsoft doesn't offer, such as the ability to create PDF files. But the biggest difference is price. You can pay hundreds of dollars for Microsoft Office. OpenOffice.org is free. It's available for Windows, Mac and Linux, and in more than 30 languages. Check it out at OpenOffice.org.
And finally today, our Website of the Week. You know, in the early days of personal computers, experts often said you could organize all your recipes on your computer. High tech has its place, but most people stayed with traditional cook books or kept recipes on file cards in a box.
With the advent of the Internet, however, exchanging recipes online has been a great way for cooks all over the world to learn how to make new dishes.
GILMORE: "Recipezaar is the largest recipe site on the Internet. All of the recipes on Recipezaar are contributed by members all around the world. We have over 130,000 recipes. Members contribute photos as well as rate and review the recipes on the website. So it's the world's largest and smartest cookbook built by real people."
That's Gay Gilmore, co-founder of Recipezaar.com. It includes more than 8,000 bread recipes, more than 1,000 corn, or maize dishes; 2000 from India; and some pretty strange ones, such as the recipe for sauerkraut Jello. The broad range of Recipezaar is reflected in its name, a contraction of "recipe bazaar."
To find just the right recipe, there are some 400 search parameters, including main ingredient, dietary category such as vegetarian, ethnicity, and so on.
GILMORE: "We allow you to do infinite searching on those catagories so you can drill down quickly and get right to Mexican main dish recipes with chicken that are low-fat and that kids will love. You can combine our categories any way that you want."
Users post recipes, and other users can rate them. Gay Gilmore says Recipezaar is powered by the great contributions of its users.
GILMORE: "We felt that some of the best cooks are people's aunts or their grandmas or a friend down the street who just makes a really mean [excellent] chili. And those recipes used to only be distributed to their friends, the people that they knew or the people in their church group. And we saw the Internet as something that could enable people to share their recipe with the world."
The site is advertising supported, with ad-free premium membership available. A great way to answer the question, "what's for dinner" ... it's recipezaar.com, or get the link from our site, VOANews.com/ourworld.
MINIDISC: Closing theme, estab for :08, then under
That's our show for this week. We're always delighted to hear from you. Ask us a science question … tell us what you like about the program, or what you don't like. Email us at ourworld@voanews.com. Or the postal address is -
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Our World is edited by Rob Sivak. Eva Nenicka is back with us again as our 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.