Our World — 8 May 2010


07 May 2010


Straight ahead on "Our World": A giant box built to cover a leaking well in the Gulf of Mexico is the best hope to stop a massive oil spill. Earthquake prediction continues to confound scientists and a map of the Neanderthal genome opens new connections to our ancient human relatives.

PAABO:

"In some of us, they live on a little bit. And that is this one to four percent of my DNA that will come from Neanderthal."

Exploring what it means to be human... that and why some mosquitoes are resistant to powerful repellants. Welcome to VOA's science and technology magazine, "Our World."

Cutting-Edge Technology Both Cause and Possible Cure in Gulf Oil Spill

As leak continues to threaten Gulf shores, BP readies a risky fix

HOST: Since the April 20th explosion and fire that sank the Deepwater Horizon off-shore oil platform, about 800,000 liters of crude oil a day have been spewing from the broken well into the Gulf of Mexico. The massive spill is threatening marine life, commercial fishing and hundreds of kilometers of coastal wetlands, where oil has already begun washing ashore. Unlike a tanker spill or a broken pipeline, this is an on-going crisis. When President Obama visited the Gulf region to assess the scope of the oil spill crisis and the steps being taken to end it, he made it clear to reporters what he sees as the top priority:

BARACK OBAMA

"We've got a bunch of different tasks. The first one is how do we plug this hole."

TEXT: That hole -- actually, gushing vents of crude oil at the damaged ocean-floor well-head nearly 2 kilometers below the surface -- was caused by the failure of a blow-out preventer. That's a pressure-sensitive safety device designed to shut off the flow of oil in case of a sudden break in the pipe leading up to the floating oil platform. Lamar McKay, head of BP America, told ABC News that attempts to use underwater robotic equipment to fix the shut-off valve are complex.

LAMAR MCKAY

"This is like doing open-heart surgery at 5,000 feet [1,524 meters], in the dark -- with robot controlled submarines."

TEXT: BP, which had been leasing the Gulf drilling platform, is leading the repair and cleanup effort. Chief Executive Officer Tony Hayward says BP has also begun drilling a relief well to intersect the existing well, bore a hole in it, and then pump in cement to plug the leak. But that job could take as long as three months to complete.

Right now, the best hope for a quick fix appears to be the 12-meter tall concrete-and-steel domed tower that BP engineers are lowering into the Gulf and place directly over the main leak. The 80-ton box would capture and siphon the escaping oil to tankers on the surface.

Richard Charter is an oil industry expert and senior policy advisor for Defenders of Wildlife. He says the dome technique has never been used at such depths and is risky.

RICHARD CHARTER/SKIRBLE

RICHARD CHARTER: "I would hope that they would be very careful in deploying those with cables and remote operating vehicles, not to bump and break off the riser pipe."

SKIRBLE: "Because if that happens..."

RICHARD CHARTER: "You would have a wide open well on the sea floor and the flow rate could increase exponentially."

TEXT: BP announced Wednesday that their robotic submersible had managed to stop one of the three sea-bed leaks. However, until the other two are capped, oil continues to flow unabated into the Gulf of Mexico. Robert Bea, an engineer with the Center for Catastrophic Risk Management at the University of California Berkley, notes that the oil is gushing from a vast reservoir:

ROBERT BEA

"The reservoir has virtually, for this disaster, an unlimited supply until we're able to seal the wells."

TEXT: The disaster response team includes U.S. government agencies and BP. BP's Tony Hayward says a massive operation is underway to contain the spreading oil slick down before it reaches shore.

TONY HAYWARD

"We're doing something that's never been done before, we're deploying dispersants on the sea bed at the source of the leak. On the surface we have a fleet of a hundred vessels to contain the spill. We are dispersing dispersant from almost an air force of planes. We've got five planes including two Hercules C-130s dispersing dispersant."

TEXT: Those dispersants, designed to break the oil into small and more manageable globules, are not without their problems, says Defenders of Wildlife senior advisor Richard Charter.

RICHARD CHARTER

"It does at sea make the oil break up into smaller particles and some of it sinks as tar balls. So in the ocean the toxicity impacts the bio-availability, if you will, of the oil toxins, and it may be greater as a result of applying the dispersant. But it may mean that fewer birds die in the marshes of Louisiana as the oil washes ashore."

TEXT: Charter says such methods to contain or slow a spill - like dispersants, skimming boats and floating booms - have been around for decades. He such methods will only address about 10 percent of the oil.

RICHARD CHARTER

"Even if you have containment booms deployed in the ocean, you quickly reach a certain sea state where the oil goes over the boom and under the boom and there is a certain component of this slick that is under the surface anyway and that just goes right under the boom.

TEXT: Berkley engineer Robert Bea -- who has worked on oil disaster teams for five decades -- compares technology developed for off-shore drilling to that developed to send astronauts into space. Bea says the pattern of repeated failures on oil rigs - including this latest disaster - points to human factors and not prevention technology.

ROBERT BEA

"Procedures, how people are selected, how they are trained at various levels, and I think that we are yet to see this kind of thinking show up strongly on board these drill rig operations."

TEXT: Bea hopes the massive Gulf of Mexico oil spill will prompt new and stricter regulations governing off-shore oil drilling operations. He says these regulations should address not only technical fixes like requiring remote shut-offs, moving operations farther from shore, and better containment strategies, but also management issues --how a rig is staffed and operated. Bea says the oil and gas industry has consistently opposed stricter federal regulation, most recently in 2009. Among the voices rejecting those rules, he says, was BP.


Earthquake Warning Systems Puzzle Scientists

HOST: There have been half a dozen strong, deadly earthquakes already this year - including those in Haiti, Chile, Turkey, and China. Does that signal an increase in global seismic activity? Experts at the U-S Geological Survey say no. The number of strong quakes falls within the normal range. Still, wouldn't it be useful if we could get advance warning of a dangerous temblor? That was one of the topics on the table when more than 500 of the world's leading earthquake experts gathered in Portland, Oregon for their annual conference recently. Correspondent Tom Banse dropped by to find out when the next Big One - greater than magnitude eight -- might strike.

TEXT: It's a question seismologists get asked all the time: When is the next Big One going to be unleashed? Steve Malone, professor emeritus at the University of Washington, has practice answering.

MALONE

A specific prediction of an event? No, I don't see that occurring.

TEXT: Not that some scientists aren't trying. Malone summarized the history and present capabilities of earthquake prediction in a talk during the annual conference of the Seismological Society of America. The international meeting featured much discussion of techniques that could someday lead to useful advance warning.

MALONE

To have a successful earthquake prediction, it means you have to know the size of it, and the location, and the time. And you have to specify it to a degree that is better than the historical background. At this point, there is no scientifically valid socially useful way to do this.

TEXT: Occasionally, someone successfully predicts the unpredictable. Malone contends that's often just dumb luck.

MALONE

Of course, animal behavior always gets a thing. -- cats are running loose, dogs are baying. Any number of reasons that might be.

TEXT: The same could be said for changing water levels in wells and fluctuations in electromagnetic fields. Last year, an Italian physics technician sparked controversy by predicting an earthquake based on rising measurements of radon gas, which is naturally released from the ground. A deadly quake struck L'Aquila, Italy a month later.

MALONE

It was studied pretty extensively and there wasn't any correlation.

TEXT: However, Malone says seismologists have enjoyed increasing success in predicting the imminent eruption of volcanoes. They've learned to recognize the swarms of small earthquakes that signal rising magma. New GPS instruments also can detect minute swelling on the flanks of a volcano about to blow.

Now scientists are deploying super-sensitive GPS monitors along major earthquake fault lines. And they're looking for patterns in low level earthquakes that could be precursors of a Big One. Malone is intrigued but cautious.

MALONE

It's nowhere near ready and may never be ready for the type of public use that the civil authorities depend upon to make a difference.

TEXT: The best researchers can give you now is a probability forecast. Oregon State University's Chris Goldfinger does that for the well-studied and ominous Cascadia fault zone, in the American Northwest. He says the section offshore of southern Oregon and Northern California has a 37 percent chance of unleashing a great earthquake in the next 50 years.

GOLDFINGER

Particularly for southern Cascadia, instead of a rather remote sounding risk of 10 to 15 percent chance that doesn't really quite rate as highly as driving on Interstate 5 in a commute rush, the message is that the earthquake hazard is higher than previously thought.

TEXT: Goldfinger studied undersea landslide debris to construct a 10,000 year record of major earthquakes along the Pacific Northwest coast. The last Cascadia earthquake was 310 years ago. If the past predicts the future, Goldfinger says his region is overdue.

GOLDFINGER

We're sitting in a pre-earthquake time just like the week before Katrina. What are we going to do about it?

TEXT: Western U.S. states and some coastal towns have started to do something to be better prepared. The town of Cannon Beach, Oregon is considering whether and how to build an evacuation tower to withstand the tsunami that could follow The Big One. The proposed building on earthquake resistant stilts would be large enough to provide refuge for more than a thousand people. It's inspired by similar structures in Japan.

Residents living on the low-lying Long Beach peninsula of Washington State realize they too may not have enough time to flee inland to higher ground. The proposed solution there is to build artificial high ground by mounding dirt, two or three stories high.

SCHELLING

The berm would be sort of circular in the front to dissipate the wave energy around it. People would access the site from a ramp in the back.

TEXT: John Schelling is the earthquake and tsunami program manager for Washington State Emergency Management.

SCHELLING

Berms may be a little more attractive than towers or buildings for a couple of reasons. One, after earthquakes people generally don't like to be in buildings.

TEXT: Schelling says a new federal grant will pay for planning and design of four berms on the Long Beach peninsula and more elsewhere in southwest Washington State. It's still unclear who would pay for the actual construction.


Scientists Sequence Genome of Ancient Humans' Closest Relative

HOST: An international team of scientists has decoded the genome of the Neanderthal, an extinct early human species that was a close ancient relative of Homo sapiens, or modern man. Researchers say they hope this first genetic map of Neanderthals will shed new light on human evolution, and on our genetic links to this ancient relative. VOA's Jessica Berman reports from Washington.

TEXT: The draft genome sequence contains more than three billion DNA letter fragments, or 60 percent of the Neanderthal genome, extracted from three fossils that were found in a cave in Croatia.

Anthropologists say the 400 milligrams of weathered bone dust was all that remained of the fossils that had disintegrated during 38,000 years of exposure to the elements, bacteria and other microorganisms. Scientists say there is also evidence that the bone fragments were deliberately crushed, possibly a sign of animal predation or cannibalism.

Researchers say it appears that early modern humans and Neanderthals interbred, probably after they had branched off from a common ancestor some 270- to 440,000 years ago.

Anthropologists say they believe this mixing between Neanderthals and modern humans occurred in the Middle East or Northern Africa, while modern humans were migrating out of Africa about 45- to 80,000 years ago.

Today, almost a half-a-million years since Neanderthals first appeared, scientists say many humans outside Africa share a very small, random portion of DNA with their ancient, extinct relative.

The finding is based on an analysis of the genomes of five present-day humans, according to the project leader Svante P??bo of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.

PAABO

"In some of us, they live on a little bit. And that is this one to four percent of my DNA that will come from Neanderthal."

TEXT: P??bo and colleagues say they believe their findings resolve a disagreement among anthropologists about whether modern humans and Neanderthals mixed.

Researchers also looked for genetic regions in modern day humans that differ from Neanderthals.

Scientists found differences in five genes, including a protein that is involved in skin formation, mental and cognitive development, and a gene tied to energy metabolism and the development of the skull and rib cage.

Co-author Ed Green, a bio-molecular engineer at the University of California, Santa Cruz, says a further comparison of human and Neanderthal DNA could point to beneficial mutations that arose from their interbreeding and that swept through modern humans.

GREEN ACT

"It turns out that this is a very powerful method for shining light on a region of time in our evolutionary history, not the evolutionary history of Neanderthals per se, but our evolutionary history and finding these important changes that happened at a really crucial time in human evolutionary history."

TEXT: Scientists say they hope that further study of the Neanderthal genome points to more differences and similarities with modern humans, and tells them whether Neanderthal also bred with cousins of prehistoric humans such as Homo erectus.

Lead researcher Svante P??bo says anthropologists are only beginning to scratch the surface in their quest for more information about Neanderthals.

PAABO ACT

"This is so exciting because the Neanderthals are our closest evolutionary relatives. If we want to define genetically what makes all humans that live today unique, not only relative to our closest living relatives, the chimpanzees, but to our closest extinct relative, the Neanderthals, we can now begin to do so."

An article describing the Neanderthal genome appears this week in the journal Science.

What does it Mean to be Human? Multi-media website explores human evolution

HOST: The Neanderthals were one of many ancient relatives on the human family tree. The Smithsonian Institution in Washington is exploring the subject in its Human Origins Initiative, which in addition to a new museum exhibit, features a website at humanorigins.si.edu. When you log on, the home page poses the age old question:

BRIANA POBINER

"That question is: What does it mean to be human?"

TEXT: And, it's the purpose of the website to explore the evidence, says Smithsonian Institution Science and Education Program specialist Briana Pobiner.

BRIANA POBINER

"Organized into behavioral evidence, fossil evidence, evidence for dating, evidence for a whole variety of things, and then also research, focusing on research of the Human Origins Program, but also the research of paleoanthropologists around the world."

TEXT: The website complements the Smithsonian Museum of Natural History's Hall of Human Origins in Washington. Pobiner says it expands on the museum's collection with information and multimedia experiences.

BRIANA POBINER

"You can almost reach out and touch and rotate the evidence for human evolution. There are hundreds of fossils, and there are dozens and dozens of artifacts and art objects that you can zoom in, rotate and take a close look at. It is almost like seeing them for yourself."

TEXT: Visitors can also take a virtual trip with a Smithsonian researcher to Kenya's Rift Valley, one of the richest sources of fossils in Africa. Pobiner says teachers are invited to join an online education forum.

BRIANA POBINER

"Teachers can exchange ideas about teaching human evolution, what has worked really well and what obstacles they face. There's a downloadable educator guide, which offers pre, during and post-visit activities for the exhibition and a variety of maps and other helpful hints for teaching human origins. There are links to a whole series of lesson plans about human evolution. There's information on our Human Origins Program Education Network, which is a new initiative that we're starting. It is really bringing scientists and educators together around the teaching and learning of human origins."

TEXT: Another popular feature on the site is What's Hot in Human Origins.

BRIANA POBINER

Any time a story breaks about a new find, whether [it's about] fossils or artifacts or DNA, we can feature it right there on our home page. And we are also constantly adding more content. In fact in the next couple of weeks we're going to add a really interactive time line, which has a variety of fossils, information about different species, information about climate change and a lot of milestones on human evolution. And you can zoom in on particular time periods and really explore.

TEXT: Pobiner hopes visitors will bookmark http://www.humanorigins.si.edu, a place where they can discover new material or engage in conversation about what it means to be human.

HOST ID: You're listening to Our World on VOA. I'm Rosanne Skirble.

Mosquitoes Develop DEET Resistance

HOST: Mosquitoes are a worldwide scourge--responsible for spreading malaria and dengue fever, among other life-threatening illnesses. And despite bug sprays, insecticide, and bed nets, the zippy little bugs are notoriously hard to avoid. New research finds that some of the mosquitoes may actually have a genetic boost that helps them get through our defenses. Naomi Seck reports:

TEXT: One of the most common ways to try to avoid the itchy torture of a mosquito bite is to spray yourself with chemical bug spray.

These often contain a compound called DEET, which repels mosquitoes.

But anyone who has spent an hour outside on a summer evening after applying mosquito repellant can tell you that you'll still get bitten.

Molecular biologist Linda Field says it's probably not because you missed a spot.

FIELD

We've been able to show that the mosquitoes that ignore DEET have a change in the way the detection of DEET occurs in antennae. What we know is the cells in the antennae, which normally pick up DEET, fail to do so in these insensitive mosquitoes.

TEXT: Field says her study shows the ability to do this, to ignore the "stay away" signal DEET normally sends, is genetic.

What's more, she says it is a dominant trait. In other words, if even one parent is able to resist DEET, it is likely their offspring will be able to, as well.

That means the resistance has the ability to spread very quickly.

Field and her team of researchers demonstrated that through a series of experiments.

First they identified mosquitoes that were naturally insensitive to DEET. Using tiny electrodes, they tested each individual sensor on the mosquitoes' antennae. They were able to see which sensor in normal mosquitoes responded to the DEET, and then show that the same sensor on the insensitive mosquitoes did not respond at all.

The next step was to breed the insensitive mosquitoes with each other to learn how often this trait was passed on.

FIELD

In our selection experiments, it built up very quickly. So we started with only about -- I think it was about -- 10%. Within two generations we were up to 60% of the population being insensitive.

TEXT: Field says these results could have important implications for global mosquito control. In the developing world, most anti-mosquito campaigns rely more on insecticide-treated bed nets or insecticide sprays than repellant. But Field says repellants are becoming more common.

Her research confirms that, at least when it comes to DEET, no one should rely on repellant, alone.

BERGMAN

Because if all mosquitoes can do this, then you have to think about the role of repellants, or at least the role of DEET, in control programs for vectors out in the field. There's a huge amount of research into vector control.

TEXT: The mosquitoes Field tested carry the dengue virus, a serious fever that infects more than 100 million people each year.

Another species of mosquitoes spreads malaria, responsible for more than a million deaths a year, including many children.

Field says future studies will look at DEET resistance in Aedes aegypti mosquitoes, to see if they also carry the resistance genes. She also wants to determine whether mosquitoes can resist other repellants.

It is important, she says, because in places where those diseases are common, even a few resistant mosquitoes could be dangerous.

FIELD

Even the odd bite is pretty dramatic. It's not a numbers game. It's not, 'well I don't want to be bitten too often.' It's, 'I don't want to be bitten at all.'

Field's research is published in the journal Proceedings of the National Academy of Science.


TEXT: And, that's our program for this week. Rob Sivak is our editor. Our technical director is Bob Doughty. I'm Rosanne Skirble. Join us online at voanews.com/ourworld or on your radio next week at this same time as we explore the latest in science and technology on Our World.