VOA标准英语2010年-Our World — 9 January 2010

MUSIC: "Our World" theme

This week on Our World: A new role for coral reefs as cradles of evolution ... a White House initiative on science education ... and solving a lead-poisoning mystery among immigrant children.

HESTING:  "We were hunting around for anything we could find that these kids might be getting into. We tested food, we tested toys — anything that we thought that that baby could have come into contact with."

Those stories, using science to free wrongfully-convicted prisoners, and more...

I'm Art Chimes. Welcome to VOA's science and technology magazine, "Our World."

 

Astronomers Discover 5 New Planets

New images from the earth-orbiting Hubble Space Telescope show galaxies forming a "mere" 600 million years after the Universe was born in the so-called "Big Bang" — more than 13 billion years ago.

The galaxies are the oldest ever observed, indicating that these vast clusters of stars were starting to form earlier in the history of the Universe than previously believed.

Astronomers say these galaxies are much smaller than our own Milky Way galaxy, and they describe them as "primordial,"  with fewer heavy elements than galaxies that formed later.

Another space telescope is in the news this week. Scientists on Monday (January 4) reported the first planets discovered by the Kepler Space Telescope, which was launched in March last year specifically to find planets orbiting distant stars.

Kepler was designed to look for planets like Earth, but as expected early in its mission, the first discoveries are much bigger planets — four of them bigger than Jupiter, and a fifth roughly the size of Neptune.

NASA scientist William Borucki says these planets race around their stars so fast, that their years are measured in days.

BORUCKI:  "The orbital periods run from about 3.2 days to 4.9 days. So these are very short orbits. The short period orbits also tell us that the planets are orbiting close to their stars, and consequently you're going to see they're quite hot."

How hot? Astronomers use the Kelvin scale, which starts at absolute zero. So frigid Jupiter is 124 Kelvin, Earth is about 300 Kelvin.

BORUCKI:  "If you continue going up in temperature, you see molten lava at about 1300 Kelvin. The planets we found are all hotter than molten lava. They all simply glow with their temperatures. Looking at them might be like looking at a blast furnace. They are very bright in their own right." 

Borucki and other Kepler astronomers discussed the newly-discovered planets at the American Astronomical Society meeting in Washington.

The Kepler orbiting telescope can't see planets directly. Looking into deep space with even the best telescope, you can't see a planet next to the large, bright glare of the star it's orbiting. So instead, astronomers look for the light of the star to dim slightly as a planet passes in front of it. Kepler is continuously monitoring more than 100,000 stars considered likely to have planets.

The challenge is weeding out false positives, when a star dims for some other reason.

BATALHA:  "Well, fortunately we have a very well laid-out plan for vetting out these false positives."

San Jose State University astronomer Natalie Batalha told reporters that some of those false positives can be eliminated by the precision and stability of Kepler's observations. But in other cases, astronomers rely on ground-based observations to confirm the finding from Kepler. It required almost 100 nights of observations from telescopes in the U.S. and the Canary Islands to confirm discovery of the five planets reported this week:

BATALHA:  "So that gives you a feel for the process, how long it takes from start to finish and how careful we are in confirming and making sure these are real signals."

Kepler's high precision is not just useful in identifying new planets around distant stars. It can tell astronomers something about the stars themselves as well as providing more detailed information about the planets it is discovering.

Ron Gilliland of the Space Telescope Science Institute says the size of one star was measured by ground telescopes to an accuracy of plus or minus 10 percent; with Kepler, the uncertainty was reduced to just 1 percent. And likewise, Kepler has refined measurements of a planet in orbit around that star.

GILLILAND:  "Before Kepler, we would have known the density of the exoplanet orbiting this star to maybe 50 percent accuracy. After Kepler, we should know that to about 5 percent accuracy. And that's absolutely critical to hope to understand the interior structure of the planets."  (:16)

One other conclusion from these first Kepler observations: many of the 100,000-plus stars in Kepler's sights are less active than had been expected -- less active in the sense of having fewer storms that would give off bursts of radiation that might threaten life on planets orbiting them.

Caty Pilachowski of Indiana University says this bodes well for those hoping to find conditions that are hospitable to life on these distant planets.

PILACHOWSKI:  "It's good news for astrobiology because if most stars are quiescent, if stars don't become terribly active then they don't scour the surfaces of their planets, and we're more likely to have habitats where life might evolve. And it increases our chances of finding that life down the road." 

Scientists working with Kepler are saying they're happy with the results they're getting. And they're looking forward to collecting a lot more data in the months and years to come that will enable them to identify planets more like Earth.

 

 

Obama Wants More Math And Science Teachers 

Almost all scientists, whether they discover planets or work in a chemistry lab, started out as science students, often inspired by a science teacher.

This week, President Barack Obama unveiled a program aimed at training 10,000 new mathematics and science teachers over the next five years. 

The quarter-billion dollar program includes funding from high-tech corporations and from universities.

Investment in programs aimed at graduating more scientists and engineers could help train a new generation ready to tackle with the president called "the grand challenges of the 21st century such as increasing energy independence, improving people's health, protecting the environment, and strengthening national security."

VOA's Kent Klein reports from the White House, where the president announced the next phase of his Educate to Innovate campaign.

KLEIN:  President Obama says young people in another countries are being better educated in math and science than American teenagers, and something needs to be done about it.

OBAMA:  "One assessment shows American 15-year-olds now ranked 21st in science and 25th in math, when compared to their peers around the world. Think about that — 21st and 25th. That is not acceptable."

KLEIN:  Part of the problem, Mr. Obama says, is a shortage of teachers. He says the U.S. will need more than 250,000 teachers in the next five years, many of them in schools that serve poor people and ethnic minorities.

The president says an additional $250 million will be spent on a teacher training program, to improve education in science, technology, engineering, and math. The money comes from a partnership between government and private institutions, and follows a $260 million commitment by the administration last year.

OBAMA:  "Several new public-private partnerships are going to offer additional training to more than 100,000 teachers, and prepare more than 10,000 new teachers in the next five years alone."

KLEIN:  The president made the announcement Wednesday as he honored 100 math and science teachers and education groups at the White House.

He also encouraged the 200,000 scientists who work for the federal government to help stimulate young people's interest in science by volunteering in their communities.

The Educate to Innovate campaign is one of several programs intended to help make the U.S. more competitive with other countries in math, science, and related fields. It accompanies Mr. Obama's Race to the Top program, in which states apply for a share of $4 billion in grants for education.

Kent Klein, VOA News, The White House.

 New Study Analyzes Gender Differences in Math Scores in 69 Countries

Historically in the United States, students going into fields like math and science have overwhelmingly been male.

That's not as true now as it once was, but many still believe that girls are, for example, not as good at math as boys. Now, some new research suggests that's not the case. Rose Hoban explains.

HOBAN:  Many people believe that women are just not 'wired' for math. Villanova University researcher Nicole Else-Quest admits that when she was a teenager — she was one of them.

ELSE-QUEST:  "I was one of those kids in adolescence, I was like, 'I don't need math.' (laughs) The biggest mistake of my life — (laughs) — thinking I didn't need math."

HOBAN:  But now, Else-Quest uses advanced math to study gender differences in many parts of society. Recently, she analyzed test scores from about a half million teenaged students in 69 countries. The data showed that overall, boys and girls scored similarly on tests that measured their abilities in math subjects, such as algebra and geometry. But within some countries, there were big differences between girls' scores and boys'.

Else-Quest compared the data to information about women's status in these countries.

ELSE-QUEST:  "And what we found is that nations in which women don't really have equity — nations where women don't enjoy good political representation or don't have the same educational opportunities or aren't achieving parity in income — that these are nations in which the gender gap in math is larger. Nations in which you find gender equity — where women have good political representation and high access to education — those are the places where you find there is no gender difference or where girls are actually outperforming boys."

HOBAN:  Else-Quest says some of the indicators of women's status in society include the number of female members of government, or their enrollment in higher education. She says girls look at the status of women around them and get a subtle message about their worth.

ELSE-QUEST:  "And I really think of it as this sort of trickling-down of the values that we place on women's achievements, and on women in society. And, you know, teenage girls aren't dumb. They see this and they say, 'OK, it's not really worth it for me to work hard in math because what do I need math for?'"

HOBAN:  Else-Quest says her research reinforces the idea that women and men have similar aptitude in math. But if society tells girls that they can't do it… they won't.

Else-Quest's research is published in the American Psychological Society's Psychological Bulletin.  I'm Rose Hoban.

 Website of the Week Highlights DNA Evidence Used to Overturn Wrongful Convictions

Time again for our Website of the Week, when we showcase interesting and innovative online destinations.

More than 7 million people are locked up in U.S. prisons or otherwise under the supervision of the criminal justice system. Despite the right to a lawyer and other protections, some of those men and women are serving time for crimes they didn't commit. At our Website of the Week, you can learn about a group that's using science in the cause of justice.

KELLEY:   "InnocenceProject.org is the website of the Innocence Project, which is a non-profit organization. We work to overturn wrongful convictions through DNA testing and also to reform the criminal justice system based on the lessons we learn from those exonerations."

Matt Kelley is Online Communications Manager for the Innocence Project, where science and law join in an effort to overturn the convictions of people wrongfully found guilty and sentenced to prison.

Michael Blair served 13 years on a Texas murder charge based in part on a supposed similarity in hair samples.

Raymond Santana of New York served five years on a rape charge based in part on a bogus confession.

An Arizona court convicted Larry Youngblood in a sexual assault on a child, and he served nine years based on the boy's mistaken testimony.

In those and other cases, DNA evidence proved the innocence of the person convicted, and in many cases pointed to the actual perpetrator.

KELLEY:   "While most of our cases are people who've been in prison for many years and were convicted before the era of DNA, there are still people being convicted in cases where DNA testing should be available and isn't conducted."

The Innocence Project is based in New York and focuses on wrongful convictions throughout the United States, but Matt Kelley says visitors from some 75 countries came to its website last year, and so the group's reach is global.

KELLEY:  "The website has become a resource for lawyers around the world to dig into forensic issues, DNA reforms, and criminal appellate representation based on trying to overturn wrongful convictions."

You can learn about the 249 people wrongfully convicted and then exonerated through DNA evidence at InnocenceProject.org, or get the link from our site, VOAnews.com.

MUSIC:  Henry Kaiser & David Lindley — "I Fought The Law"

It's Our World, the weekly science and technology magazine from VOA News. I'm Art Chimes in Washington. 

 Coral Reefs Play Important Role in Incubating New Species, Study Shows

A new study out this week highlights the role that coral reefs play in evolution, adding another reason to preserve these delicate, diverse, and often beautiful ecosystems.

Many of the world's coral reefs are threatened by ocean acidification and pollution, among other things.

Wolfgang Kiessling of Berlin's Natural History Museum says that concerns ecologists because of the key role reefs play.

"They're really important to marine ecology because they host thousands of fish, for example. This is where the young fish grow up. And they host millions of species of invertebrates, and so they are ecologically really key to tropical marine ecosystems."

The conventional view has been that reefs attract such a diverse population in part because they have lots of nooks and crannies where fish can hide from predators

So: ocean reefs as hotbeds of diversity, but not necessarily places where new species arise.

Kiessling began to doubt this when he looked at the evolutionary record following the mass extinction 65 million years ago that wiped out the dinosaurs. That event signalled a slowdown in the creation of new species.

"We see that evolution slowed a bit, and this was basically — that was my guess — because so many reefs were killed as well. So it took a long time for diversity to build up again in the aftermath."

Using a vast, online catalog called the Paleobiology Database, Kiessling and his colleagues analyzed the occurrence of hundreds of thousands of new species as documented by researchers around the world.

"And we found that 50 percent more than we would expect by chance did first occur in reefs."

In an interview, Kiessling — who is also a professor at Germany's Humboldt University — said he was surprised to find that this idea of the reef as a cradle of evolution even applies to species not known as reef-dwellers. They may evolve in the reef environment, then migrate elsewhere.

"So species get generated, like even clams and snails, crabs, and so on, and then, when they — later in their evolutionary history, they move out of the reefs, and then they export diversity, basically, to other areas." 

All of which, he says, suggests that there's more reason than ever to safeguard ocean reefs.

"The biggest outcome of our study is how really important reefs are for evolutionary processes, not just for ecology. So when we lose reefs, we lose basically the cradles of evolution in the oceans in the long run."

Wolfgang Kiessling describes his reasearch in a paper published this week in the journal Science.

 Lead in Traditional Remedy Poisons Immigrant Youngsters

It was more than 30 years ago that U.S. authorities banned lead from paint, after confirming that the toxic metal was making children sick — children who licked or ate chips of paint containing lead. Lead was also a common additive in gasoline, but no more. So with less lead in the environment, the problem of lead poisoning in children in the United States has been decreasing. But every once in a while, health officials find a dramatic spike in the number of lead poisoning cases, and the race is on to find the source. Erika Celeste reports on a lead poisoning case involving some refugees from Burma who have settled in the midwestern U.S.

 CELESTE:  Two years ago, Mah We [mah wee] took her baby daughter and fled the unrest in Burma to Fort Wayne, Indiana. She wanted her daughter to have an American name when she got here. She settled on Snow White after seeing the Disney movie. Now her little girl is three and a half years old.

Q:  Hi, Do you like school?

SNOW WHITE:  School, yes.

Q:  What's your favorite thing at school?

INTERPRETER:  Play with my friends.

CELESTE:  Snow White has had a lot of challenges in her young life. Blood tests revealed she has lead poisoning. Exposure to lead can cause brain damage, I.Q. loss, behavioral problems, and in rare cases, death.

Most U.S. communities have low rates of childhood blood lead poisoning — averaging 1.2 percent of the total population. But with the new influx of Burmese immigrants, Fort Wayne's exposure rate rose to 12 percent. Amy Hesting is with the Allen County Health Department:

HESTING:  "We kind of assumed it was something that had come over from the [refugee] camps, that they had been poisoned when they were in the camps, and just weren't identified until they got to the United States."

CELESTE:  But then, new siblings were born into some of the Burmese families. At birth, the babies' blood levels were normal, yet within a few months, those levels became dangerously high.

Most small children get poisoned when they crawl on the floor, get dust from old lead paint on their hands, and then stick their hands in their mouths.

HESTING:  "They weren't doing that — the babies weren't old enough to do that yet — and so why they had a blood lead level of in the 20s, made no sense to us."

CELESTE:  With the cases mounting and the source still unknown, the Centers for Disease Control helped Hesting assemble an investigative team. They set up a makeshift field office and went door-to-door in the Burmese apartment complexes.

HESTING:  "We were hunting around for anything we could find that these kids might be getting into. We tested food, we tested toys — anything we thought that that baby could have come into contact with."

CELESTE:  They tested more kids. And they took samples of various household items. Then, there was a break in the case. Two traditional Burmese medicines [daw tway and daw kyin], geared specifically to small children for tummy aches, came back with extremely high levels of lead.

Hesting was relieved to finally have an answer. But it didn't solve the problem.

Aye Ma is a Burmese translator. She says many parents didn't believe Hesting or her team.

AYE MA:  "The mother was pretty upset. She referred back to her ancestors, 'Oh, my ancestors have been using this medicine and how can you come and out of the blue tell me this is no good, this has lead in it?'"

CELESTE:  While some families are taking the advice to stop using the medicine, others are still skeptical. Even though the medicines are banned in the U.S., families can still get a hold of them through connections back home.

Hesting says she's still seeing new cases of lead poisoning. But because she isn't certain the medicines are the only cause, educating the families about lead poisoning remains important.

Officials have set up a pilot preschool program for kids like Snow White. The program will help the kids catch up through speech, cognitive, and nutrition therapy. So far it seems to be a great success.

While this was an unusual case for the U.S., the CDC reports that many traditional medicines from East Indian, Middle Eastern, Western Asian, and Hispanic cultures still contain lead.

For The Environment Report, I'm Erika Celeste.

Support for the Environment Report on VOA comes from the Joyce Foundation, and the Great Lakes Fishery Trust. You can find more stories and post your comments at EnvironmentReport.org.

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