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This week on Our World: A new satellite to monitor Earth's potentially climate-changing carbon emissions... testing new drugs in developing countries ... and engineering a water system upgrade for New York City...
CHRIS SMART: "This tunnel that we broke into is over 100 years old. We like the way it was built. I hope that within 100 years, the guys look at the work we've done, they say the same thing."
Those stories, a mental health Website of the Week, and more.
I'm Art Chimes. Welcome to VOA's science and technology magazine, "Our World."
NASA launching satellite to monitor CO2 on Earth
Tuesday morning, U.S. time, the space agency NASA is scheduled to launch a satellite that will look down on earth to monitor sources of carbon dioxide as well as places called carbon sinks, where CO2 is absorbed. Carbon dioxide, of course, is one of the principal greenhouse gases widely believed to be responsible for global warming. Reporter Tom Banse says the Orbiting Carbon Observatory satellite is designed to help scientists get a handle on the ins and outs of the carbon cycle.
BANSE: Washington State University professor George Mount is on the trail of a mystery. Our cars and factories and all of us produce lots of carbon dioxide, a key culprit in global warming. But tracking it isn't easy.
MOUNT: "About half of the CO2 that is produced stays in the atmosphere."
BANSE: The other half disappears somewhere...
MOUNT: "A lot of it goes into the ocean. Obviously, a lot of it goes into plants."
BANSE: Places that absorb a lot of carbon dioxide are called "sinks."
MOUNT: "People are very interested scientifically and politically in where on the globe these sinks of carbon dioxide are."
BANSE: It's not hard to conclude that owning a carbon sink could be a valuable thing in a world worried about global warming. The difficult part is figuring out where the good sponges are. That's where George Mount comes in. The atmospheric scientist is part of an international team helping design and test NASA's first satellite to track carbon dioxide.
MOUNT: "The idea of the satellite was to make extremely accurate measurements of CO2 from space, where you can get global coverage of the CO2 concentration and can then start to quantify where it's coming from and where it's going."
BANSE: Mount says the Orbiting Carbon Observatory detects odorless, colorless CO2 indirectly from its vantage point 690 kilometers above the earth.
MOUNT: "CO2 is a copious absorber of infrared light. And the photons of light that travel from the sun go through the atmosphere once, hit the ground, reflect back up, go through the atmosphere again, and then up to the satellite sensor. So it'is possible to deduce the abundance of the molecule [by measuring the difference in the amount of infrared light]."
BANSE: George Mount says the timing of the upcoming launch couldn't be better. Lots of countries, states, even some county governments and corporations are trying to figure out how their carbon emissions and sinks balance.
The vast tracts of public and private forestland in the northwestern United States are an obvious sink. The giant timber and paper company Weyerhaeuser owns nearly one million hectares in the region. Spokesman Frank Mendizabel says the company finds it challenging to determine how much carbon dioxide its tree farms soak up.
MENDIZABEL: "It's a very difficult thing to measure and has a lot of technical details, I think, yet to be worked out."
BANSE: Data on greenhouse gas concentrations for any part of the planet should start to become available a few months after the Orbiting Carbon Observatory is launched.
For Our World, I'm Tom Banse in Pullman, Washington.
Vaccines could be delivered by bacteria, not needles
Vaccines have been one of the greatest public health achievements in history. Doctors have developed vaccines to prevent some of the world's most terrible diseases, including smallpox and polio. But one of the limitations of vaccines is that they need to be injected with a needle, and they often need more than one dose to be effective. As we hear from health reporter Rose Hoban, it would be much easier if all vaccines could be given by mouth.
HOBAN: Now scientists think that might be possible.
Microbiologist Todd Klaenhammer from North Carolina State University has spent his career studying the kinds of bacteria that we add to food, such as lactobacillus acidophilus.
KLAENHAMMER: "We eat this in yogurt and a lot of different products every day. So it's totally safe, you can eat these things at over 100 million per gram."
HOBAN: Klaenhammer and colleagues realized they could use these food-safe bacteria to 'sneak' a vaccine into the gastrointestinal tract without damaging the vaccine's potency.
KLAENHAMMER: "If you eat a vaccine, just a pure vaccine, your stomach will degrade it, and it will no longer have any vaccine potential. But if you can put the vaccine, if you will, inside these food-grade bacteria, the bacteria can survive passage through the stomach, and then once in the small intestine, they can present the vaccine to what we call the mucosal immunity system."
HOBAN: These cells in the mucous lining of the gastrointestinal tract are a key part of the immune system. When the mucous cells recognize the vaccine-laden bacteria, they signal the rest of the immune system to resist the organism targeted by the vaccine.
Klaenhammer says he and his colleagues used this technique to give a vaccine against anthrax to mice in the laboratory.
KLAENHAMMER: "These oral delivery strategies are effective - 85 percent I think the number was, and that was equal to the injectable vaccine."
HOBAN: Klaenhammer says one of the advantages to this technique is that it would make storage and distribution of vaccines much, much easier.
Klaenhammer says it should only be a year or two before he and his colleagues could start testing this technique in humans. His research is published in the Proceedings of the National Academy of Sciences.
I'm Rose Hoban.
US drug companies increasingly testing drugs overseas
No matter how they're administered, vaccines - and all medicines, for that matter, have to be tested to ensure they're safe and effective.
A new study indicates that major U.S. pharmaceutical companies are increasingly testing new medicines in developing countries. As VOA's Jessica Berman reports, overseas testing raises questions about government oversight, safety and quality control, and the value of the findings.
BERMAN: Researchers at Duke University in North Carolina looked at recruitment records for some of the largest drug trials as of late 2007 conducted for the top U.S.-based companies and found that about one-third of those trials were conducted overseas.
The researchers also found that the number of foreign countries used as trial sites rose sharply between 1995 and 2005, while the number of trials conducted in the United States and Western Europe declined.
Duke University's Kevin Schulman led the research review. He says drug trials required for U.S. regulatory approval cost pharmaceutical companies much less when performed overseas. But Dr. Schulman says caution is needed.
SCHULMAN: "We don't want there to be a lower ethical standard; we don't want to put people at risk around the world; we don't want people to be exploited to participate in clinical research. And clearly, we need the answers to these questions to be appropriate to the markets where these products are going to be available."
BERMAN: He says some drugs - for example, allergy medicines - are tested in areas where they probably will not be sold.
The Pharmaceutical Research and Manufacturers of America said in response to the study that American companies are developing drugs for a worldwide audience.
Dr. Schulman says large clinical trials might benefit local populations, bringing needed health care and wealth to poor communities. But he says these benefits need to be weighed against the risks of testing new drugs.
The U.S. Food and Drug Administration, which oversees drug studies in the United States, has increased the number of its investigators abroad to monitor foreign drug trials by American companies.
But the Duke University researchers warn that the FDA is not equiped to adequately monitor the studies. And Dr. Schulman says there are concerns about whether foreign drug study participants are fully informed of the potential risks involved in pharmaceutical testing before agreeing to participate.
SCHULMAN: "We don't have a huge ability to go monitor for ethical violations, although there have been documentation in the literature where people haven't been offered informed consent. I think this is the challenge with the work at this point."
BERMAN: Dr. Schulman says he knows of no instance when clinical trial participants have been harmed.
The Duke University researchers are urging more international collaboration and openness among the pharmaceutical industry, academic institutions conducting clinical trials, and regulatory bodies in developing nations to ensure the safety of clinical trials.
The study looking at overseas clinical drug trials was published this week in The New England Journal of Medicine.
Jessica Berman, VOA News, Washington
Some progress reported against neglected tropical diseases
Pharmaceutical companies are constantly developing new medicines, but often the issue is getting existing drugs to the people who need them.
There is, frankly, a lot more money in treating high cholesterol or sexual dysfunction than there is in the so-called neglected tropical diseases that affect some of the world's poorest people.
Some charities have stepped in. The Bill and Melinda Gates Foundation, for example, recently committed $34 million to help battle these parasitic diseases. VOA's Melinda Smith has a progress report on efforts to combat these illnesses.
SMITH: The World Health Organization reports that about one billion people are affected by Neglected Tropical Diseases.
Guinea worm, river blindness, hookworm, schistosomiasis, trachoma, lymphatic filariasis and sleeping sickness are some of the diseases in this group.
They are spread by insects and contaminated water and soil.
From 1975 to 1999, according to the WHO, less than one percent of the 1,300 new drugs on the market were targeted for treatment of neglected tropical diseases.
Dr. Peter Hotez of the Global Network for Neglected Tropical Diseases says getting money for treatment was difficult until the Gates Foundation addressed the need.
HOTEZ: "So it is a real hurdle to get drugs, vaccines, diagnostics for these NTDs, neglected tropical diseases, developed. All I can say is, thank God for the Bill and Melinda Gates Foundation that has stepped up, come through and led the way in terms of research and development."
SMITH: Dr. Hotez says the $34 million from the Gates Foundation will help treat seven of the most common Neglected Tropical Diseases at an average cost of 50 cents a year per person.
The cost of treatment is kept down, he says, because five of the needed drugs will be donated for free or at low cost by pharmaceutical companies.
The near eradication of the guinea worm is perhaps the greatest success story among the group of Neglected Tropical Diseases.
Guinea worm disease has existed since the beginning of civilization. Ancient mummies, exhumed centuries after burial, have shown traces of Guinea worms.
In modern times, guinea worms are more commonly found in people who live in rural areas without adequate sanitation.
Craig Withers is an expert on guinea worm disease with the Carter Center in Atlanta, Georgia.
WITHERS: "The people who have this disease are in the most remote, rural, poorest areas of the world. They live in unhygienic environments."
SMITH: Guinea worm disease occurs when stagnant water used for drinking and bathing is contaminated by the worm's larvae.
When a person comes into contact with the infected water, he or she ingests the larvae which then mature and mate. The female worm grows and then breaks through the human skin.
Craig Withers says the cycle continues when the infected person seeks relief from pain by going into the water.
WITHERS: "People go to that water to cool off the sensation, and as soon as you touch the water, the eggs are emitted into the water."
SMITH: Two decades ago, guinea worm infestation was at its peak in 20 countries in Asia and Africa. Three and a half million people were infected.
Then, in 1998, former U.S. President Jimmy Carter visited Ghana and saw how guinea worm disease made life miserable for the villagers.
He organized a coalition of international health agencies to fan out and teach local people how to eradicate the disease.
Today, only about 5,000 cases of guinea worm disease still exist, primarily in southern Sudan.
Melinda Smith, VOA News
Mental health advice and community on our Website of the Week
Time again for our Website of the Week, when we showcase interesting and innovative online destinations.
This week, it's a free resource where you can get information, help and support, plus answers to your questions about mental health issues.
GROHOL: "PsychCentral.com is a mental health website where we discuss information about mental health concerns like depression and anxiety, and the information we offer includes things like symptoms of these kinds of disorders as well as treatment of them."
John Grohol is founder of PsychCentral.com, which includes a virtual encyclopedia of conditions facing adults and children, from anxiety to Tourette's. And while the site includes serious topics such as depression and schizophrenia, it goes beyond what you might consider matters of mental illness.
GROHOL: "We also have a great deal of resources about kind of everyday living concerns, such as parenting and relationships, and how do you deal with stress, because they're all interrelated and they all have to do with your mental health. We are big advocates of helping people find that kind of information."
PsychCentral.com also features online chats and a place to post your specific question, where it will be answered by a trained expert. But for many people, what may be most helpful are the 140 online support groups in PsychCentral's forums.
GROHOL: "You talk to other people who have the similar kind of concern as you do. And other people will respond and say, 'here's what's helped for me, and maybe you'll find this helpful. And here's some resources that you can go and read.' So it really acts as a mutual aid kind of place where people share with one another, and through that sharing, they benefit."
Information about mental health issues plus online support groups at PsychCentral - that's P-S-Y-C-H - PsychCentral.com, or get the link to this and more than 200 other Websites of the Week, from our site, voanews.com/ourworld.
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It's VOA's science and technology magazine, Our World. I'm Art Chimes in Washington.
Building New York's water system for the 21st century
Alongside some of the world's great natural wonders are some of the great achievements of human engineers.
From the pyramids of ancient Egypt to the skyscrapers and bridges of the modern world, it's hard not to be impressed.
Deep under the streets of New York, sandhogs - we'll explain that in a minute - sandhogs are at work on one of the great ongoing engineering projects of our time. It's an enormous tunnel to add capacity to New York's water supply system. The new tunnel, 40 years in the making, will supplement two existing tunnels, which are a century old. My colleague Rosanne Skirble went down, deep below city streets, for a first-hand look at perhaps the largest and most complex public works project currently underway in the Western Hemisphere.
SKIRBLE: While life goes on normally above ground on city streets, 40 meters under the Van Cortlandt Park golf course in the Bronx, New York, Morgan Curran has a job to do.
CURRAN: "My title is walking boss. That means that I am the boss on this shift, which starts at three in the afternoon and we work until 11 at night."
SKIRBLE: Curran is a New York City miner known as a sandhog.
CURRAN: "People don't know much about what we do. We're always underground, and we do all the tunnels in the city."
SKIRBLE: The Croton Water Filtration Plant is a three-tunnel job. Curran says crews had to first mine a cavernous staging area then install an elevator, lay down railroad track, connect power cables, and put in a pump to get out the muck as they blast and dig.
CURRAN: "This was a solid mass. Where we are standing right now there were no tunnels. We came through the wall of the pit and we blasted our way here until we got enough room to make way for these tunnels that you see behind me, and then brought a [rock] boring machine in and we done one side and we done the other side."
SKIRBLE: Three or four meters per day, every day.
CURRAN: "So you generate a lot of material from that when it's broken up, and it takes a couple of shifts to muck it out, and then you do it all over 14 feet [4.2 meters] at a time, that's how we opened up this huge cavern up."
SKIRBLE: The sandhogs are about half way through the four-year job. Chris Smart, the project engineer and surveyor does the math and technical drawings.
SMART: "It comes down to the end, a cross on the wall and spray [paint] showing the shape of the tunnel and the guys drill that and if they go left and right, each time we slowly adjust them. And we just slowly by slowly just keep drilling and shooting [dynamite] until we connect to the other tunnel and we just break in to the other [connecting] tunnel."
SKIRBLE: Both Smart and Curran agree that teamwork is required to get the job done safely in this high-risk environment.
CURRAN: "I need him, and he needs me."
SMART: "Morgan knows very well how to run the machines, run the crews. He knows the rock conditions. He knows how to drill and blast. Without his cooperation, I don't get a tunnel going the right way. And if you miss a connection to another tunnel, the tunnel is useless."
SKIRBLE: ? and a multi-million dollar setback.
The tunnel adjoins the filtration plant construction site, an area bigger than two football fields side-by-side and nine stories deep. Trucks loaded with building materials circle the grounds as cranes lower supplies to the teams of workers in the massive pit. On this day, the acting commissioner of the New York City Department of Environmental Protection, Steven Lawitts, checks on the progress.
LAWITTS: "There will be a small entrance building above ground, and that is all people will see in terms of the plant. The plant will be completely underground. At the end of the construction project the golf course will be restored and in fact it will look better than before construction started."
SKIRBLE: Lawitts is charged with keeping New York's drinking water secure and available to eight million people. His job also includes managing infrastructure projects like the filtration plant and Water Tunnel Number Three.
LAWITTS: "The whole point of constructing Water Tunnel Number Three and other redundant features is to prevent an unexpected leak and unexpected disaster from occurring. While the chances of disaster are very small, we want to ensure that it doesn't happen at all."
SKIRBLE: Engineer and tunnel surveyor Chris Smart says he uses technology that didn't exist 100 years ago and both he and acting commissioner Lawitts marvel at the sophistication of work from that earlier era:
SMART: "This tunnel that we broke into is over 100 years old. We like the way it was built. I hope that within a hundred years the guys look at the work we've done, they say the same thing."
LAWITTS: "That? that was a sound decision to make to build a third water tunnel, to build a filtration plant, to fix the infrastructure upstate, and to clean the New York harbor."
SKIRBLE: The Croton Water Filtration Plant is expected to be completed by 2012. The 100-kilometer, $6 billion Water Tunnel Number Three won't be finished until 2020. Rosanne Skirble, VOA News, New York.
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That's our show for this week. If you'd like to get in touch, email us at firstname.lastname@example.org. Or use the postal address -
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Rob Sivak is our editor. Bob Doughty 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.
Our World — 21 February 2009
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