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MUSIC: "Our World" theme
Straight ahead on "Our World," ... a new planet discovered in a new way ... boy-girl ratios at times of stress ... and an Internet game that helps scientists track disease
ESKIN: "The fact that it might be able to help humanity in some way, other than an interesting diversion on the Internet, is a wonderful thing, and I really applaud them for putting this together."
Those stories, a new campaign against tuberculosis, our Website of the Week, and more. I'm Art Chimes. Welcome to VOA's science and technology magazine, "Our World."
A team of 73 astronomers from 10 countries has combined observations from their telescopes to identify the smallest planet ever found outside our solar system.
That barely counts as news anymore. In the past 11 years, some 170 extrasolar planets, as they're called, have been identified.
But Michael Turner of the National Science Foundation says this latest discovery is different because the astronomers used a newer technique that holds the potential of identifying many more planets, including some that could be Earth-like.
TURNER: "The validation of the microlensing technique is as important as the result announced today because of its future potential."
At a press briefing, astronomers presented a video that explained microlensing. It's based on Einstein's prediction that light, which normally travels in a straight line, could be bent by gravity. When starlight passes by another star on its way to us here on Earth, that star's gravity can bend the light like a giant magnifying glass. But as the video explained, it doesn't take something as big as a star to have an observable effect.
VIDEO: "Astronomers call it a 'microlens' when the effect is created by a very dim object that wanders in front of a distant star and focuses the light just enough to make the star just a bit brighter. This makes microlensing a powerful tool for detecting objects that would otherwise be lost in the vastness of space."
Most of the planets that have been discovered so far have been much larger, on the order of Jupiter, the largest planet in our solar system. But Dr. Bennett says astronomers think the smaller planets are actually a lot more common, just harder to see.
BENNETT: "The higher mass planets are much easier to discover. If the Jupiters were as common as these [smaller] planets, we would expect to see dozens of them by now, and we've only seen two. And if you extrapolate from that, then maybe Earth-mass planets would be even more common than these."
Of course, there's no guarantee an Earth-like planet will harbor life.
Scott Tremaine of Princeton University, who was not a member of the microlensing research program, commented on the importance of the discovery.
TREMAIN: "The discovery really demonstrates, I think, for the first time, that we have the capability of detecting planets with masses and orbits similar to the Earth, but what I think is equally important is that these discoveries were made with small telescopes and modest resources, and there are really no technological limitations to increasing the size and scope of these surveys at costs that are still modest by the standards of big science."
The findings were published this week in the journal Nature.
The World Economic Forum in Davos, Switzerland, was the setting Friday for a call to increase funding for tuberculosis treatment, and prevent 14 million deaths from the disease over the next decade.
The plan includes a new vaccine and better treatment, and would cost $56 billion. Most of the money is expected to come from governments, but Microsoft founder Bill Gates was on hand to promise his foundation's contribution would triple.
GATES: "In the past we've spent $300 million on tuberculosis funding. During this next period we'll triple what we spent, so we'll spend during this period over $900 million."
Unlike disease such as AIDS and malaria, treatment for tuberculosis is cheap and relatively simple. Nevertheless, Britain's Chancellor of the Exchequer Gordon Brown told reporters in Davos that ?
BROWN: "Every 15 seconds someone dies of tuberculosis ? avoidably, and as Bill Gates has said, preventably."
The World Health Organization says there are nine million new TB cases each year.
The new TB program would aim to expand treatment, plus invest in the development of new vaccines and drugs. To meet its target, the plan needs another $31 billion in commitments.
Another disease that has a lot of people worried is avian, or bird flu. The WHO this week confirmed two deaths in Indonesia from the deadly H5N1 strain of the disease. Since it was identified in humans three years ago in China, 80 of the 150 people infected have died from this variety. Fears of its spread have led to the slaughter of 50 million birds. As VOA's Rosanne Skirble reports, WHO officials warn that H5N1 could trigger a global pandemic.
SKIRBLE: It is rare for avian influenza to move from birds to humans. World Health Organization spokesman Richard Thompson says infection comes directly from contact with sick poultry or from feces from diseased birds mixed in the soil. The WHO believes all of those infected so far had been exposed to poultry they didn't know was infected.
THOMPSON: "Farmers or their families come along, and to prepare the animals for consumption they de-feather the [birds]. And in the act of pulling the feathers off these dead birds, dust flies up, and we believe that inhaling this dust has led to most of the infections in humans of the virus."
SKIRBLE: Worldwide outbreaks of a single disease are rare but reoccurring events, having been recorded historically every 10 to 50 years. WHO's Richard Thompson says vigilance - not panic - is in order.
THOMPSON: "There were three pandemics in the last century. Most people alive today lived through two of them without really noticing them. This wasn't a major trauma to societies or economies or even to health systems. So pandemics can occur which have relatively minor effects."
SKIRBLE: Others, like the 1918 Spanish Flu pandemic, killed 40 million people. No one can predict whether H5N1 will trigger such a pandemic, and - if it does - how long it would last or how deadly it would be.
For that to happen, experts say the virus must first mutate, or change so that it could pass easily among humans.
SKIRBLE: Thompson says H5N1 - like other strains of influenza virus - is also highly unstable, and natural changes could give it the ability to move efficiently from one person to another. Thompson says a pandemic outbreak is identified by how the virus attacks people.
THOMPSON: "If, for example, we started to see clusters of human cases - not family members who may have had common environmental exposures, but rather casual contacts - [like] an ambulance driver who took a patient to the hospital or a nurse who had been tending to a patient. That would be a signal to us that this is the kind of clustering of cases that might signal the beginning of a pandemic."
SKIRBLE: For now, though, the H5N1 virus has apparently not yet passed from person to person, so only those who come into contact with infected birds are at risk.
WHO is also calling on governments to increase surveillance for early detection and to develop emergency plans to help contain the spread of a highly pathogenic virus. (SIGNED)
When it comes to lung cancer rates among smokers, scientists say race and ethnicity matter. A new study reports significant differences in the rates among smokers from five U.S. ethnic and racial groups, with the highest among blacks and native Hawaiians. VOA's David McAlary reports.
McALARY: The incidence of lung cancer in the United States is highest among blacks and Polynesians and lowest among Japanese-Americans and Hispanics, with whites in between. Some people have thought that differences in smoking behavior might account for this disparity. But a study in the New England Journal of Medicine shows that these relative disease rates remain even when the number of cigarettes smoked is comparable.
Researchers from the Universities of Southern California and Hawaii examined lung cancer rates among 184,000 American men and women of European, African, Japanese, Hispanic ancestry and native Hawaiians. Their average age was 60.
They found that of those who smoked 20 or fewer cigarettes a day, the blacks and native Hawaiians had the greatest risk of lung cancer. Whites had about half the risk of these two groups, while Japanese-Americans and Hispanics had one-fifth to two-fifths the risk respectively.
The reason why is a mystery.
HAIMAN: "The factors that explain these differences we don't know about."
McALARY: This is the lead author of the study, Christopher Haiman [HI-man] of the University of Southern California. He says differences in lung cancer risk among racial and ethnic groups cannot be explained by diet, occupation, socioeconomic status or other known or suspected factors. He suggests one reason might be genetic differences in how their bodies process the cancer-causing chemicals in tobacco.
HAIMAN: "There could be variation in how different populations metabolize nicotine, which could influence smoking behaviors such as the intensity of smoking ? the depth and frequency of inhalation ? and therefore influence the uptake of carcinogens. We know there are genes that are shared across populations, but they have different frequencies which could make some populations more susceptible to the effects of tobacco smoke."
The research shows that racial and ethnic differences in lung cancer risk disappeared among heavy smokers in the study. Their chance of getting the disease was similar if they smoked 30 or more cigarettes a day.
Whether the findings can be applied directly to ancestral populations in Africa, Europe, and Japan is unclear. American racial groups are a blend of genetic heritages. According to one expert on disease distribution among populations, Neil Risch of the University of California at San Francisco. from the policymaking point of view, the ethnic and racial differences in lung cancer are unimportant.
RISCH: ""From the public health perspective, these findings don't really matter because it shows that the ethnic differences pretty much disappear when you eliminate smoking. So from the perspective of public health, it may not be that helpful."
But both Risch and study author Christopher Haiman say such findings could be useful for the information they might provide about the mechanisms by which cancer causing compounds influence the risk of disease. David McAlary, VOA News, Washington.
The U.S. Senate is likely to vote this week to confirm the nomination of Samuel Alito to the Supreme Court. The Alito appointment came less than four months after John Roberts was sworn in as Chief Justice. But even when there are no new appointments to the nine-member Supreme Court, however, the high court is never out of the news for very long here. Our Website of the Week provides an up-close look at this key institution of our government.
MARSHALL OF THE SUPREME COURT: "The honorable The Chief Justice and the Associate Justices of the Supreme Court of the United States. Oyez, oyez, oyez. All persons having business ...
GOLDMAN: "Oyez.org is a multimedia database devoted to the United States Supreme Court."
Jerry Goldman is the Northwestern University professor behind Oyez-dot-org, sometimes also pronounced oh-yezz.
The Supreme Court is the top tribunal in the U.S. judicial system. Perhaps more so than high courts elsewhere, the U.S. Supreme Court is the ultimate authority, with the power to invalidate legislation as unconstitutional and, in 2000, to decide a disputed presidential election. To understand the way the American government works, you can't ignore the Supreme Court.
The court publishes its decisions, of course, and releases transcripts of its sessions, but broadcasts are prohibited. Since 1955, however, the court has made audio recordings, and many of those are now available at Oyez-dot-org.
Each year, 5,000 or more cases are appealed to the Supreme Court, but the court will only accept fewer than 100. In almost all of them, lawyers will appear before the nine justices for oral arguments, a spirited question-and-answer session on the legal merits of their case.
GOLDMAN: "It's an engaging way to hear lawyers and justices argue about great principles, and sometimes very minor ones. In each of the cases, though, you can rest assured that something significant is at stake. And sometimes the attorneys are fantastic; sometimes they're just absolutely terrible. So it's an engaging experience."
The Oyez Project includes more than 2000 hours of audio recordings of Supreme Court proceedings, including all oral arguments that have been released since 1995. There's also a selective archive of earlier cases for listening or download.
In many cases, the transcript is displayed as the audio plays, which is a great help to English students.
GOLDMAN: "It provides a good exposure to spoken English in a real-life environment, not someone reading a text from a teleprompter or a piece of paper, but the actual give-and-takethat comes from ordinary language discussion. And that I think is a valuable resource for those who want to learn the language."
In addition, Oyez-dot-org has links to news about the court and its cases, and links to the text of Supreme Court decisions.
Our Website of the Week is Oyez-dot-org, or get the link from our site, voanews.com/ourworld.
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You're listening to VOA's science and technology magazine, Our World. I'm Art Chimes in Washington.
Researchers have long observed that during times of social stress, there are fewer male births than female births. Now, a new study has found that boys born during those tough times live longer than those born during periods of social stability. VOA's Jessica Berman explains.
BERMAN: Drops in male-to-female sex ratios are nothing new.
Ralph Catalano is a professor public health at the of University of California at Berkeley.
CATALANO: "During the Kobe earthquake in Japan, sex ratio drops. The collapse of the east German economy, sex ratio drops. The major smog in London in 1952, sex ratio dropped. Variation in the economy such that you get very bad economic times in Sweden over a century and a half, sex ratio drops."
BERMAN: Then, when environmental factors return to normal, experts say sex ratios even out.
Most scientists believe the dip in sex ratios is a stark example of evolution at work: through a process of natural selection, the theory goes, daughters are better able to propagate the species than weaker sons.
The mothers' bodies seem to spontaneously abort weak male fetuses more often by exposing them to high levels of the stress hormone cortisol in utero, while sparing the females.
Professor Catalano says cortisol acts as an evolutionary "testing mechanism" to weed out weaker male fetuses.
CATALANO: "And what we're interested in is whether the mechanism itself, the testing mechanism, of the fetuses actually damages those that survive, because the presumption has been that if you've been subjected to this kind of regimen of cortisol production in utero, that it has health consequences that affect you in life if you've made it to birth."
BERMAN: That's one theory. Professor Catalano and colleague Tim Bruckner also wanted to explore another notion, that sons who survive end up living longer and healthier lives than males born during less stressful times.
They decided to look at cohort data in Sweden of babies born between 1751, the first year the Swedes began keeping birth records, and 1912.
Based on the male-to-female birth ratios over the 160-year period, the investigators found that the fewer males that survived the cortisol challenge in utero lived slightly longer than sons born during periods of relative calm.
Again, Professor Catalano.
CATALANO: "Our work suggests that at least historically, smaller cohorts of males than you would expect from the number of females does not mean that that cohort is a relatively fragile cohort. In fact, quite the contrary, those cohorts may be relatively hardy even though they may be smaller because the weakest of them are no longer there."
BERMAN: Professor Catalano doesn't think the findings are likely to have any impact on the way a doctor interacts with an expectant mother.
The study on sex ratios and lifespan were published in Proceedings of the National Academy of Sciences. Jessica Berman, VOA News, Washington.
Finally today, every so often I come across a story that really opens my eyes. This week, it was a story about developing a mathematical model for how people move from place-to-place -- a formula that could be useful in predicting the spread of epidemic disease. That's a great subject, but what amazed me was where the scientists got their information.
The lead researcher, Dirk Brockmann, told me he couldn't find a source of raw data that would include airplane trips across oceans, as well as shorter trips by rail, road, bicycle and foot.
BROCKMANN: "I knew what I would need for a model for the spread of disease: and that is, the probability of a human traveling a certain distance ? how many journeys of 10 kilometers occur as opposed to journeys of 100 kilometers as opposed to journeys of, say, 1000 kilometers."
Dr. Brockmann, a theoretical physicist at the Max Planck Institute for Dynamics and Self-Organization in Germany, was visiting a friend in the United States, and told him about his frustration. The friend ? a cabinetmaker, not a scientist ? immediately thought about Where's George.
WheresGeorge-dot-com is an Internet-based game that tracks the movement of paper money around the United States.
BROCKMANN: "And when I saw the website, I realized that this distribution of distances will exactly mimic the distribution of human traveling.
Fifty million banknotes have been registered in Where's George by their serial number. If a bill is logged a second time, you can see where it started, where it went, and how long it took to get there.
The creator of WheresGeorge.com says he was a bit reluctant to provide the data at first, as he had worked with other researchers in the past, but they never published their findings. At the end of the day, though, Hank Eskin says it was a good experience.
ESKIN: "The fact that somebody was able to take those data, convert it into something meaningful to support their theories and their research is wonderful. I think it's a wonderful thing. And if we can do it in the future for other projects, that would be good, too. The fact that it might be able to help humanity in some way, other than an interesting diversion on the Internet, is a wonderful thing, and I really applaud them for putting this together."
Back in Germany, Dr. Brockmann and his colleagues got records of almost a half-million currency movements from the website, which they then analyzed to produce a set of rules that could guide epidemiologists and public health officials as they prepare for the spread of a disease such as avian flu.
Once they had the data, it was a matter of finding the right mathematical equations to describe the movement of money ... or people, people who might carry disease. But Dirk Brockmann cautions that his work represents only one piece of the puzzle.
BROCKMANN: "We presented a theory that accounts for the traveling only. And you have to understand [that] a model for the spread of disease consists of many ingredients ? travel only being one ingredient."
And he stressed that further testing and refinement of his model is needed.
BROCKMANN: "We will, of course, take our results and plug them into models that are constructed to account for the spread of, you know, modern diseases like SARS or influenza, or childhood diseases like measles. But we are not at that stage yet."
Dirk Brockmann is the lead author of "The Scaling Laws of Human Travel," the article in this week's issue of Nature.
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