This transcript is provided as a service; there may be some variation between it and the program as broadcast.
MUSIC: "Our World" themeStraight ahead on "Our World" ... One year after a deadly hurricane season, the outlook for this year ... a comeback for DDT ... and a preview of the International AIDS conference ...
DE CAPUA: "When you consider that some six million people are estimated to need the drugs, and only maybe about one million or so maybe have it, there's still a big, big gap."
Those stories, the latest climate change research, and more. I'm Art Chimes. Welcome to VOA's science and technology magazine, "Our World."
Government forecasters said on Tuesday they expect this year's North Atlantic hurricane season to be more active than normal. The chief hurricane forecaster for the weather service, Gerry Bell, told reporters that the United States and Caribbean countries are looking at probably three to four major hurricanes this year out of an expected 12–15 named storms.
BELL: "Today's updated outlook calls for a high likelihood — a 75 percent chance — of an above-normal season. However and fortunately, the possibility of an extremely active season, such as we saw last year, is greatly reduced."
This week's hurricane outlook updates an earlier projection. They're still forecasting an active hurricane season, but a bit less active than it looked in May.
The annual hurricane season is of intense interest in the coastal southeastern United States, Mexico, Central America and the Caribbean, where these tropical cyclones can do tremendous damage. Last year's storms included Hurricane Katrina, which killed more than 1,000 people and caused billions of dollars in damage.
Hurricanes begin as low-pressure areas off the Atlantic coast of Africa and pick up energy from the warm, tropical ocean as they move west. So, is the recent run of stronger, more frequent hurricanes a reflection of global warming, or just part of a normal cycle? The head of the U.S. ocean research agency, NOAA, Conrad Lautenbacher, suggested more study is needed on the issue.
LAUTENBACHER: "Some research suggests global warming is linked to rising ocean and sea surface temperatures in the tropical Atlantic and the Gulf of Mexico, which may have an impact on hurricane intensity. It is important to stress that there are many factors which impact hurricanes, and NOAA supports and values a wide variety of research, which will help to identify those factors and their impact on hurricane freqency and/or intensity."
NOAA administrator Conrad Lautenbacher. Incidentally, the government forecast is generally consistent with one issued last week by Colorado State University.
We're so used to seeing satellite weather pictures that it's sometimes easy to forget that the satellite era is less than 50 years old. Months after the first satellite — the Soviet Sputnik — was launched, the first U.S. orbiter went into space in 1958, and unlike Sputnik, Explorer One had a science package on board including radiation instruments developed by a team led by James Van Allen.
Van Allen died Wednesday at the age of 91. His instruments discovered radiation surrounding the Earth — the Van Allen radiation belts, they were named, in his honor.
Space continues to be a platform for scientific inquiry, including two papers published this week, both related to climate change, but from opposite ends of the world — literally.
Starting in the far north: scientists have used satellite-based gravity measurements to calculate how fast ice is melting in Greenland.
TAPLEY: "The result picks up a rate of melting that is deduced by the ice melting [and] running off into the ocean and changing the gravitational signal of Greenland. It picks up a rate that's large enough to be of some significance. The indication would be consistent with I think at this time fairly well-established global warming impact."
Writing online in Science Express, Byron Tapley and his colleagues at the University of Texas Center for Space Research calculated that Greenland is losing about 240 cubic kilometers of ice per year. That's more than twice as much as estimates less than a decade ago.
Unlike ice in the Arctic Ocean, which has also been melting, this is ice that has been sitting on land, which means when it melts and runs into the sea, it can raise sea level. In addition to that possible long-term threat, Tapley says there's a shorter-term threat to ocean currents, because most of the melting ice is on the east side of Greenland.
TAPLEY: "And there is concern that this fresh water, introduced into the North Atlantic circulation, a polar gyre just off the eastern side of Greenland, if that fresh water will essentially mess up the return flow and stop that current from carrying warm water up into that northern trend, and it would have a fairly significant climate impact."
In other words, the addition of fresh water could disrupt the currents that help warm northern Europe. Byron Tapley says a number of published papers have suggested that, rather than a gradual change, ocean currents could change abruptly when they hit a so-called tipping point.
In other research published this week in the journal Science, an international team analyzed 50 years of snowfall over Antarctica. With warmer oceans causing more evaporation, they expected to find an increase in snowfall in recent years. However, using data from satellite and ground observations, lead researcher Andy Monaghan says they didn't find any increase.
MONAGHAN: "And that's an important finding for several reasons. One, because we're kind of expecting an increase in a warmer atmosphere, and that would act to slow sea level rise a bit, because if you get more snow falling on these [Antarctic] ice sheets, then that means there's less water in the ocean. And so you kind of have a braking mechanism to slow sea level rise."
That evaporating water has to go somewhere, and Monaghan theorizes it may rain or snow back into the southern ocean, which won't help counteract rising sea levels from ice melting elsewhere ... like Greenland.
Andy Monaghan from Ohio State University notes one important limitation in the study: there is tremendous variation from year-to-year and decade-to-decade in the amount of snowfall, which makes it hard to project a trend with the data they have.
Time again for our Website of the Week, when we showcase interesting and innovative online destinations. This week we're featuring two related websites that highlight notable United States inventions.
At the Gallery of Obscure Patents at Delphion.com/gallery, it's an amusing look at some of the more curious products ever awarded a patent.
MELE: "There are some that really range from the very strange or bizarre to some that do look useful. So I guess beauty is in the eye of the beholder, and I think the same thing would apply in the invention realm."
Peter Mele is a product manager at Thomson Scientific, the company that runs the Delphion website, which provides full-text patent documents for professional users. He says they devised the Gallery of Obscure Patents as a lighthearted way of introducing users to their product. But it is fun to see that inventors spent time and money to patent such odd innovations as the bird diaper or a biodegradable toothbrush.
MELE: "My all-time favorite is the greenhouse helmet. It's a totally sealed, glass helmet with plants inside, so a person can breathe oxygen that's given off by the plants."
There's also the ever-popular toe puppet, and of course the motorized rotating ice-cream cone.
On a more serious note, and just a click away, is the Gallery of Historic Patents, at Delphion.com/historic, with the original patent documents to some of history's most important innovations.
MELE: "Thomas Edison's initial electric light bulb. The telephone by Alexander Graham Bell. So I think a lot of people can really identify with that, just in terms of, you know, when you think of inventions, certainly they're some of the people that you've heard about, and it's just very interesting as you go through the patent literature where it's actually retrievable."
The American patent system was actually established by our Constitution in 1789, and the country's founders included at least a couple of inventors — Benjamin Franklin and Thomas Jefferson.
The Galleries of Historic and Obscure Patents at Delphion.com/historic and Delphion.com/gallery provide only partial patent documents for free, but if you want to see the complete patent, we've got a link to a free service on our site, voanews.com/ourworld.
MUSIC: Don Harriss: "Inventions"
And you're listening to VOA's unpatentable science and technology magazine, Our World. I'm Art Chimes in Washington.
It's about time we dug into the Our World mailbag to answer a listener question, and we've got a great one from Hemant Suhay, writing from Muzaffarpur, Bihar state in India. Hemant is secretary of the Cosmos Club, a shortwave listener club whose members we hear from frequently, and actually his question has to do with the cosmos: "How do space probes navigate large distances with such accuracy, and how do mission controllers know when they've reached their target?"
That's a great question, and for the answer we turned to the man who guided America's Cassini spaceprobe to Saturn. Cassini was launched in 1997, swung by Venus a couple of times for a gravity assist,passed by Earth for another nudge and then Jupiter for more of the same, before finally arriving at Saturn in 2004, almost seven years after launch. So you can see there was plenty of work to do for Jeremy Jones, the mission's chief navigator. We reached him at NASA's Jet Propulsion Laboratory in California. Jones said navigation is a two step process, starting with what amounts to a really good map of the neighborhood.
JONES: "The first part is really knowing where all the of planets and other bodies in the solar system are. And the reason that's important is we are taking measurements from earth. So we really want to know where the spacecraft is relative to the Sun or relative to Saturn or whatever the large body in the vicinity is. So once we know where everything in the Solar System is to some accuracy, then we have a probe, and we take measurements from Earth using in our case the Deep Space Antennas. And the way we track them is, we send signals from the ground stations to the spacecraft. The spacecraft essentially just turns the signal around, it shouts back to us just exactly what we [sent to it]. And then we measure the difference in the received signal from what we sent up. And by subtracting those two we can get a very accurate measurement of velocity between the spacecraft and the ground station."
In other words, by measuring the time delay, mission controllers can determine the distance between earth and the spacecraft, and by measuring the Doppler shift — the same thing that causes a train whistle to change pitch as it goes past you — they can tell the speed at which the spacecraft is traveling.
It's a highly sophisticated process, but Jones says spacecraft navigation has a lot in common with what sailors here on earth did centuries ago.
JONES: "Ships at sea used the stars to essentially do their best navigation when they couldn't see the land. And there we knew the latitude of the stars. If you looked up you could determine your latitude, how far you were north or south. And the big problem was the longitude. And then finally, in the 1700s the British developed a very accurate clock. And once you knew the clock time, then you could figure out where you were in longitude. Same thing for us. The reason we can get such accuracy is that we have a very, very good clock."
NASA's Jeremy Jones says onboard navigation is starting to appear on spacecraft, but so far, just for relatively simple tasks. That technology could permit the spacecraft to respond quickly to changing circumstances, and also save a lot of money on ground control operations.
Hemant Suhay, we hope that answers your question. We'll be sending him a special VOA gift as our way of saying thanks. If you've got a science question, our email address is OurWorld@voanews.com, or listen for our postal address at the end of the show.
Global efforts to eradicate malaria have long relied heavily on the powerful chemical DDT to kill the mosquitos that spread the disease. But DDT was banned decades ago in many countries because of its potential toxic effects. As VOA's Rosanne Skirble reports, renewed support from global health agencies is helping to put DDT back in the battle against malaria.
SKIRBLE: Most experts agree: DDT is the most effective weapon in the war against malaria.
But use of DDT was curtailed by a ban in the United States in 1972. More recently it was targeted for phase-out under the United Nations Convention on Persistent Organic Pollutants in 2001.
While DDT was never fully outlawed, its use throughout the world has been greatly limited by the refusal of large donor agencies and development groups to purchase the insecticide.
But the increasing human toll of malaria has changed the mood of the international community. One million people die of the disease each year. Ninety percent of the 300-500 million annual cases are in Africa, where its prevalence in some countries is greater than HIV/AIDS.
In May of this year, the United States Agency for International Development endorsed DDT for malaria control, following the lead of the UN's World Health Organization. Dr. Shiva Marugasampillay with WHO's Global Malaria program says indoor insecticide spraying with DDT has proven both effective and safe.
MARUGASAMPILLAY: "If you look at countries like Namibia, which is using DDT, Botswana, Zimbabwe. At the moment Mozambique has started again and also Zambia. Another country that has shown tremendous success is Eritrea."
SKIRBLE: Dr. Marugasampillay says these successes have helped guide the new WHO policy, which is based on scientific studies and advice from government and health officials.
MARUGASAMPILLAY: "The main focus of the recommendations is to re-look at indoor residual house spraying as a tool for malaria control and the use of DDT as appropriate among other chemicals and also to help in developing new chemicals which we could use to substitute for DDT."
SKIRBLE: The change in U.S. policy allows government aid agencies to support international programs that use DDT. According to Don Roberts, professor of tropical public health with the U.S. Armed Services University of the Health Sciences, that's an important break with the past.
ROBERTS: "I think that is a very good message. I think that it is a constructive message and I think that use of U.S. taxpayer money for that is way overdue. And I believe that it will save lives and think that it will greatly reduce the amount of disease in countries that choose to use it."
SKIRBLE: While environmental groups led the fight to ban DDT in the United States and phase out its use globally, activists like Ed Hopkins with the Sierra Club's Environmental Quality Program do not oppose the use of DDT to fight malaria.
HOPKINS: "We think that it is important to protect the health of people in the developing world. So if there are no better alternatives than DDT, we support the controlled use of that chemical."
SKIRBLE: Other critics fear DDT will be misused, difficult to monitor and pose a threat to wildlife and the environment. WHO's Shiva Marugasampillay disagrees.
MARUGASAMPILLAY: "When you are actually importing DDT in a country it can only be imported by the national public health agency and it will only be delivered mainly through the public health agency or others which the public health agency will supervise and in that way it will be highly controlled."
SKIRBLE: Marugasampillay says indoor spraying is an important strategy in the campaign against malaria. But he adds that the success of that campaign will also depend on whether countries have strong, well-organized public health systems to safely and effectively manage the use of DDT. I'm Rosanne Skirble.
This coming week, thousands of scientists, doctors, activists and journalists will gather in Toronto for the 16th International AIDS Conference.
VOA reporters, as usual, will be on the scene, including Joe DeCapua from our English to Africa service. I spoke with Joe before he left for Toronto, and I started by asking about that conference theme, "Time to Deliver."
DE CAPUA: I spoke with one activist the other day from Thailand, and I asked her that question, and she said, 'when you go to these things it's talk-talk-talk-talk-talk, lot of discussion. But then very little action, follow-up.' So the idea behind 'Time to Deliver' is, get up, let's actually do something.
QUESTION: There really is a great divide, it seems, for people with HIV/AIDS. If you're in a wealthy country like the United States, Canada — where the conference is taking place — or Europe, it's generally a chronic condition. It's serious, but it's treatable; there are medicines, they're expensive, but there are medicines available. In a lot of the rest of the world, though, that's not true, and particularly in sub-Saharan Africa, where treatment is often out of reach. Is that gap going to be addressed at the Toronto conference?
DE CAPUA: That gap has been addressed now for many, many years, and anti-retroviral drugs are starting to get out there, including the president's PEPFAR [President's Emergency Plan for AIDS Relief] program but, when you consider that some six million people are estimated to need the drugs, and only maybe about one million or so maybe have it, there's still a big, big gap. It's getting there, but it's been a long, slow battle, and you get very much into moral issues, not only economic ones when you deal with this issue.
QUESTION: I was going to say, what is it beyond the money issue?
DE CAPUA: You're dealing with the accusations that the rich nations don't care about the poor nations, that the big drug companies really just want to make a profit and want to sell their drugs in the rich countries. And now many of the companies are making the drugs available at a much lower price. They're making the drugs available in single-pill form, which makes it much easier when you're in a 'resource-poor setting' or poor country where you don't have refrigeration or a great deal of health workers.
QUESTION: You know, one thing that distinguishes these AIDS meetings going back to the 1980s is that in contrast to a lot of these other scientific meetings, it's not just for scientists and doctors. You've got activists, you've got policy people, and an assortment of very interesting characters often. What do you expect to see, or who do you expect to see at the Toronto AIDS conference, and what do the non-scientists add to the mix?
DE CAPUA: I tell you, some of the favorite people that I like to talk to are the AIDS activists, people who come there who are HIV-positive — and many of them wear T-shirts that say 'I am HIV-positive.' You sit down and you talk to them, and you hear some of the most amazing stories, heartbreaking stories, but amazing stories how these people have lost so many members of their families, how they have started AIDS organizations with absolutely no money. It's just amazing.
QUESTION: This is, I think, your fifth conference?
DE CAPUA: This'll be my fifth.
QUESTION: How have they changed over the years? How has the tone changed, in particular?
DE CAPUA: Ten years ago at the Vancouver conference, the first one I went to, is when they announced the success of anti-retroviral drugs. And they were even at the time thinking that maybe this is a cure. Of course, it didn't take long after that to find out that it wasn't a cure, that if you stopped taking the drugs, the virus would reappear. So that's changed. It's become more realistic in that sense. I think there was a big change in 2000 in Durban. That was the first time it was really in a developing country. And that's when it really shifted focus. You talk about the science; that's when they really started putting an emphasis on the community and social aspects. But this conference, they say science is going to have a prominent role. Dr. Helene Gayle, the president of the International AIDS Society is also the co-chair of this conference, and she says, make no mistake about it, there'll be plenty of science. And there are thousands and thousands of scientific papers that are going to be presented. You can't follow them all. It's just too many.
QUESTION: It really is logistically a bit of a nightmare, and you're going from one presentation to the next and you get buttonholed in the hallway by someone you really want to talk to....
DE CAPUA: You see four stories you want to cover, and they're all at the same time.
QUESTION: Of course. They do that, I think, deliberately. Joe De Capua from VOA's English to Africa service. We'll be looking forward to hearing your reports this coming week. Thanks very much.
DE CAPUA: Thank you.
MUSIC: "Our World" theme
That's our show for this week. If you've got a science question or just want to get in touch, email us at email@example.com. Or use our postal address -
Voice of America
Washington, DC 20237 USA.
Rob Sivak is our editor. Eva Nenicka is 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.