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This week on Our World: Some positive news on the state of global fisheries ... an online report on the health of bird species ... and the challenges that remain in wiping out polio ...
BARRETT: "What goes on in small villages in a remote part of Nigeria will determine a return that we're going to get here in the United States as well as elsewhere."
Those stories, high tech tracking of migrating salmon, malaria's origins in an ancient chimp ancestor, and more.
I'm Art Chimes. Welcome to VOA's science and technology magazine, "Our World."
Kepler Telescope Searches for Planets with Potential for Life
In March, NASA launched the Kepler spacecraft designed to look for planets similar enough to Earth that they might support some kind of life.
For the past four months, scientists have been testing Kepler's instruments, and on Thursday they called in reporters to announce the results.
BOSS: "The bottom line is, the real headline for this whole press conference is: Kepler Works."
That's Carnegie Institution astrophysicist Alan Boss, one of the scientists working on the project.
The Kepler team pointed the spacecraft at a distant star where a large planet, about the size of Jupiter, is known to exist.
Kepler's instruments detected the planet, seeing the star get slightly dimmer as the planet passed in front of it, blocking some of the light.
But it also detected something even harder to see. The planet observed by Kepler is so close to its sun that it glows red hot. Kepler's instruments detected the change in light as the planet orbited its star, rotating its bright, heated side away from Kepler, then back again in view. It's like our Moon gets darker or lighter depending on whether we're seeing the side illuminated by our Sun.
Alan Boss says these early results prove that Kepler is up to the task it was designed for - finding the smaller, hard-to-see planets that might support life.
BOSS: "Kepler is being launched, not just to find Jupiters - that's sort of a secondary product - but its prime mission is to count how many earths there are around sunlike stars in our region of the galaxy. We now know that Kepler can do it. But the question that remains is, how many earths are actually out there for Kepler to find."
Kepler will spend the next several years, keeping its electronic "eye" pointed at more than 100,000 stars, looking for signs that they may be home to earthlike planets.
Hopeful News for Restoring Global Fish Populations
Fish are an important source of healthful food, and that's why experts have been sounding the alarm that we are taking too many fish out of the world's oceans and pushing some populations to the brink of extinction. But a new study finds signs of hope that depleted fisheries around the world can be restored. VOA food reporter Steve Baragona has details on a new study that suggests threatened fish stocks may not be quite so threatened after all.
BARAGONA: Three years ago, a study assessing the health of global fisheries caused a stir when it predicted that the populations of all commercially-fished ocean species would collapse by 2048.
The new study, published in the journal Science, confirms that an increasing number of fish populations are collapsing. But it finds that the steps taken around the world to reverse that trend are working. The rate at which fish are being taken out of the sea has dropped to a level that should allow fish populations to recover in five of the 10 regions studied.
WORM: "This means different regions are heading in different directions and some regions have indeed begun to eliminate overfishing."
BARAGONA: That's Boris Worm at Dalhousie University in Canada. He's the lead author of both the new study and the controversial 2006 study. Worm and a group of 20 collaborators from around the world looked at what strategies had helped successfully rebuild fish populations.
For example, in the northeastern United States, populations of haddock and other fish had been devastated by overfishing, beginning the 1960s. But in the 1990s, federal fishing authorities took aggressive action. They limited how many days fishers could spend at sea. Certain areas were closed to fishing entirely. Authorities required fishers to use gear that let smaller fish escape. And they set limits on the number and size of fish that could be caught. Study co-author Mike Fogarty of the National Oceanic and Atmospheric Administration says these measures worked.
FOGARTY: "Today we've witnessed a dramatic recovery of haddock to the highest levels we've seen since the 1930s, when actual population estimates were first available."
BARAGONA: And success stories can be found in the developing world as well. The study highlighted the experience in Kenya, where fish populations grew after fishers agreed to use different nets and not to fish in certain areas.
But Africa's fisheries face another threat, according to study co-author Tim McClanahan of the Wildlife Conservation Society:
McCLANAHAN: "Most countries in Africa are selling fishing rights to industrialized nations which catch large amounts of seafood, essentially outcompeting local fishermen through the contracts signed by their own government representatives."
BARAGONA: The study shows that when industrialized nations tightened restrictions on fishing, seafood companies moved their fleets to the waters off developing countries with fewer restrictions. The study authors say better global oversight is needed so that one nation's efforts to rebuild its fish populations don't come at another nation's expense.
Steve Baragona, VOA News, Washington.
Researchers Use Technology to Track Young Salmon
In America's Pacific Northwest, salmon are an important fish, both economically and symbolically. They travel to and from the ocean through rivers, making their way around dams. To track their migration, scientists are implanting tiny radio and audio tags to follow the fish and plot their movements. Anna King reports from the John Day Dam, straddling the Columbia River, on the Oregon-Washington state border.
KING: Getting around a dam is especially hard for juvenile salmon on their way to the Pacific Ocean. All that rushing water and noise makes them confused. While they swim back and forth, trying to get past the barrier, they become easy targets for predators like birds and larger fish.
Biologists are trying to solve that problem here at the fish tagging lab at John Day Dam. A dozen people scurry around with shallow containers holding young salmon. James Hughes, with the Pacific Northwest National Lab, explains that the fish don't flop out, because they've been drugged.
HUGHES: "Once the fish loses equilibrium and is basically at the stage that this one is in, we take him from here to our data station and take all the metrics on him."
KING: After some measurements, the tiny fish is quickly shuttled in the container to the operating table.
A tiny incision, two stitches and the whole surgery takes about a minute. Now there are two transmitters inside the belly of this little 10 centimeter long salmon. One of them is a long-lasting radio tag. It emits a signal whenever the fish swims near a special antenna along the river. The other puts out a coded ping. This sonic tag has a much longer range and provides much more detail about the fish's location.
But as senior scientist Jeff McMichael notes, this tiny ping has to be detected over the roar of the dams. Standing on top of John Day, he points to turbines, thousands of popping bubbles, cascading water from the spillway, electrical generators ...
McMICHAEL: "That's a lot of noise."
KING: However, the scientists found a frequency that can blast through that underwater din.
McMICHAEL: "We chose a place in that noise environment [where] there wasn't very much noise."
KING: Now, a tagged fish can be heard by an underwater receiver as far as three football fields away. Researchers have placed hundreds of those receivers up and down the Columbia. Computers translate the tracking data they receive into an animation. That cartoon shows the movements of hundreds of tagged fish.
Scientists already know that some go directly through the turbines, others go over the spillway, still others make their way down the water slide built to help young fish around the dam. But the new sonic tags draw a more detailed image of what's happening with the tiny fish, showing exactly where they get mixed up or delayed on their downriver journey.
McMichael says most salmon make it around John Day just fine. But he wants to know why some don't, and eventually the data he's collecting could be used to modify the dam and change the facility's operations.
McMICHAEL: "You know, all the easy questions have been answered. And it's the hard ones that remain. So, they're challenging, and when you are able to produce and get information that's necessary to make decisions, it's rewarding."
KING: On a boat three kilometers upriver from the John Day Dam, the baby salmon are let go, five at a time. A scientist lowers a big bucket into the Columbia, and the fish silently slip out and glide down into the greenish depths.
They still have the John Day Dam to contend with and 350 more kilometers of river to the Pacific Ocean. Along the way, thanks to their pinging bellies, scientists will be watching their every move.
For VOA News, I'm Anna King in Arlington, Oregon.
Deadly Malaria Parasite Traced to Chimp Ancestor
An international team of researchers reports that the malaria parasite that causes the worst form of the disease in humans originally jumped the species barrier from an ancestor of chimpanzees. Scientists say the discovery could lead to better treatments for malaria. VOA's Jessica Berman reports.
BERMAN: Both humans and chimpanzees, our closest primate relative, can become infected with a mosquito-borne parasite that causes malaria.
The human parasite, known as plasmodium falciparum causes, malignant malaria, the deadliest form of the disease, which sickens an estimated 500 million people globally each year, killing more than one million individuals, most of them children.
For years, evolutionary biologists believed that malignant malaria evolved millions of years ago in humans and that plasmodium reichenowi, a relatively benign form of the pathogen in chimps, evolved separately in primates.
But an international team of scientists, conducting a genetic analysis of reichenowi, has concluded that the chimp parasite - carried aloft by infected mosquitoes in equatorial Africa - jumped to humans and became falciparum, possibly as recently as 10,000 years ago.
Stephen Rich, head of the Department of Plant, Soil and Insect Sciences at the University of Massachusetts in Amherst, led the study that determined the origin of the deadly human malaria parasite.
RICH: "For a scientist, that's an exciting opportunity to figure out exactly which genes or which characteristics are the ones that make falciparum - the human parasite - so deadly and the chimp one more or less benign."
BERMAN: The researchers conducted a DNA analysis of malaria parasites taken from the tissue of 94 wild-born chimps in Cameroon and Ivory Coast, and compared it to falciparum.
The scientists determined that deadly falciparum is distantly related to three other parasites that cause malaria in humans, but is most closely related to reichenowi, which jumped from the chimpanzee lineage to our common human ancestor.
Evolutionary biologist and study co-author Francisco Ayala at the University of California Irvine doesn't find that surprising, given that genetically, humans and chimpanzees are 98 percent identical.
AYALA: "No doubt the fact that we are closely related to chimpanzees makes the possibility of transmission more likely because we are genetically very similar."
BERMAN: Researchers suspect the enhanced virulence of malaria occurred as early man turned from a hunter-gatherer existence to settled agrarian societies, in which mosquitoes were able to spread vast numbers of parasites to human hosts.
Stephen Rich of the University of Massachusetts says the fact that falciparum jumped the species barrier means that scientists are going to have to be vigilant about other primate parasites doing the same and causing serious new illnesses in humans.
RICH: "We know from our study that this has happened in the case of falciparum arising from an ancestor of reichenowi in the not too distant past and so, yes, that does present the opportunity that these things could be recurring all the time. And without much further sampling, we're just not going to be able to figure out how often that happens."
BERMAN: Rich predicts his team's finding will spark surveillance efforts for the emergence of new human pandemics from wildlife.
The study on the origin of malignant malaria is published this week in Proceedings of the National Academy of Sciences.
Jessica Berman, VOA News, Washington.
Website of the Week Features 'State of the Birds'
It's time again for our Website of the Week, when we showcase interesting and innovative online destinations.
This week it's a report on the status of birds in America, and what that says about our environment.
CHU: "The State of the Birds website is a place where anyone can go to find out how birds are faring in the United States based on the first comprehensive analysis of data in the last 40 years."
Miyoko Chu is communications director at Cornell University's Ornithology Lab, which hosts StateOfTheBirds.org.
The site focuses on the 800 bird species found in the United States, but Chu says the challenges they face are similar to those faced by birds everywhere.
CHU: "So the challenges that you'll see on the website are the same types of challenges that affect birds wherever they go: development, such as urban development, climate change. These are challenges that birds are facing in just about every place around the world."
The State of the Birds is the result of a collaboration involving several government agencies and private conservation groups.
The site reports on threatened bird species, but also on success stories of birds that are no longer considered endangered.
CHU: "Birds are actually a great indicator of the larger state of the environment. So the trends that we see for birds are often early warnings of how well our environments are doing. And by paying attention to that information, we can avoid environmental catastrophes that affect not only birds, but wildlife and people."
Scientists are already at work on an update of the site, due next year, that will focus on the impact of climate change. You can visit the site at StateOfTheBirds.org, or get the link to this and more than 250 other Websites of the Week from our site, VOAnews.com/ourworld.
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You're flying along with Our World, the weekly science and technology magazine from VOA News. I'm Art Chimes in Washington.
New AIDS Drug Combination May Help Some Patients
A new study of a drug that's been used as a last resort against HIV - the virus that causes AIDS - shows that it's as effective in initial treatment as the drug that's typically prescribed, and produces fewer side effects. Meredith Hegg reports.
HEGG: Successful use of a relatively new HIV drug called raltegravir in patients unresponsive to other treatments, led medical professor Jeffrey Lennox and his colleagues to test if the drug would work in infected patients who had not yet taken medications for HIV.
LENNOX: "What the study showed was that for people that had never been treated before, that a combination that included raltegravir was as effective as a combination that included efavirenz, and efavirenz is considered the standard of care at this point. In addition, raltegravir in general had less side effects and was better tolerated than efavirenz."
HEGG: The issue of cost also plays a large role in determining which drugs health organizations recommend, according to Lennox. In places like Africa, the higher cost of raltegravir has limited its use.
LENNOX: "In the past, for instance, efavirenz wasn't used because it was more costly than another drug called nevirapine. But now the price of efavirenz is going down in Africa so they're switching to efavirenz in many countries. At some point in the future if raltegravir becomes cheaper, then they might use it more widely. But right now it's really not available for most patients."
HEGG: Though the raltegravir study suggests a new use for the anti-HIV drug, other scientists are advising caution. Marco Vitoria of the World Health Organization says the study's short, 48-week span leaves some important unanswered questions.
VITORIA: "You don't have studies for long term use. Then nobody can really be sure that there's no risk of a long term side effect that is not detected in trials yet."
HEGG: But Vitoria acknowledges that raltegravir is still important for patients who've developed resistance to other drugs.
VITORIA: "Patients that have previous experience with other drugs, without other options for treatment, certainly the drug is a good option."
HEGG: The next step will be to conduct longer term studies. Lennox's research is published in the journal, The Lancet. I'm Meredith Hegg.
Expert Identifies Obstacles to Polio Eradication
Finally today ... In the 1970s, public health workers around the world organized in a successful effort to eradicate smallpox.
A more recent effort to wipe out polio has so far failed.
Why hasn't the program to end polio succeeded? And what can be done to improve the chances of success?
Some possible answers come from Scott Barrett of Columbia University in an article published in the current edition of the journal Health Affairs.
Speaking in Washington recently, Barrett recalled that the effort to wipe out smallpox could easily have failed.
BARRETT: "First of all, it barely succeeded. You know, these things, when they happen, we sort of take them for granted, which is why you need to read history. And the history of smallpox shows that it was a very close call and may not have succeeded and to some extent we're fortunate that it did."
Like smallpox, polio is a highly contagious disease. The battle against it began in earnest around 50 years ago, when two different vaccines were developed - first, an injectable vaccine that used a dead polio virus, and then one that used a weakened but live virus. The live-virus vaccine, which is given by mouth, is a lot cheaper, but can actually cause polio in a very small number of cases.
Efforts since the 1950s to eradicate polio have achieved remarkable success, but the disease stubbornly persists in a handful of places, and Barrett says that eliminating polio from those remaining pockets is challenging and may not succeed.
BARRETT: "So it's a gamble. We may win; we may not win."
That said, he identified a number of challenges to the complete eradication of polio in the regions where the disease remains endemic.
In the Afghan-Pakistan border region, eradication programs face factional fighting and sometimes-violent opposition to vaccination.
In two northern states in India [Uttar Pradesh and Bihar], vaccination can fail to protect children who have other virus infections or diarrhea.
And in Northern Nigeria, vaccination was suspended in 2003 after political and religious leaders claimed the vaccine was contaminated with HIV among other things.
Funding an expensive eradication program is another challenge. The Nigerian boycott prompted the European Union to temporarily stop donations. Officials estimate more than $2 billion will be needed over the next few years to fund the vaccination effort. But Barrett describes disease eradication as an investment.
BARRETT: "You undertake eradication not only to prevent from getting disease in the future, and of course there's a return we get on that, but also to avoid the need to vaccinate in the future."
That's known as the eradication dividend.
Barrett stresses that eliminating polio will have benefits beyond those gained in the areas where it remains a threat.
BARRETT: "Our fates, in many ways, are so interlocked. This is a good way to understand the concept of globalization. What goes on in small villages in a remote part of Nigeria will determine a return that we're going to get here in the United States as well as elsewhere."
But Columbia University's Scott Barrett says that even if polio is wiped out, the world will have to maintain vigilance against a potential reemergence of the disease.
BARRETT: "After eradication has been achieved - let's hope it will be achieved - and has been certified, there's always the risk that it will break out again, and then the post-eradication risk will depend on our ability to jump on it and suppress it before it has had a chance to spread."
Scott Barrett spoke in Washington at an event sponsored by the journal Health Affairs, where his paper appears in the current issue.
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