This is SCIENCE IN THE NEWS in VOA Special English. I'm Bob Doughty.
And I'm Pat Bodnar. This week: The world's largest protected marine area ...
And the search for some very old objects stolen in the American South ...
But first a report on "monster tumors."
Researchers are studying the qualities of an unusual kind of cancer called a teratoma. They hope to use teratomas for stem cell experiments, without the need for human embryos. Scientists are experimenting with stem cells to try to develop medical treatments.
Embryonic stem cells are able to grow into the different kinds of cells and tissues in the body. But the stem cells can be collected only when an embryo is destroyed. Opponents of such research say it destroys human life.
Teratoma cells form a large mass in the body. The cells develop like a fertilized egg. The name teratoma comes from a Greek word for monster. Like some frightening creature, teratomas can grow hair, teeth and skin. But they can also produce stem cells.
Some researchers think teratomas offer a better way to see how cancer drugs will act in humans than tests on mice.
But mice could be a way to produce a supply of teratomas to use for testing medicines. A recent report in the New York Times described work by researchers in Israel. They injected stem cells from human embryos into the legs of the mice. The animals developed teratomas.
The researchers then put laboratory-grown cancer cells into the same areas. The cancer cells quickly spread through the teratomas, producing what the scientists think is a fertile place to test drugs.
Teratomas can produce many different kinds of human tissue, so drugs could be tested on different kinds of cells. But some researchers think they may be most valuable for their stem cells.
Teratomas that develop from egg cells lack the biological programming of embryos. So their stem cells could be used for research, but could not develop into human beings.
Growths on the lower back, called sacrococcygeal teratomas, are common in children. Teratomas generally do not become malignant, the most serious form of cancer. Still, they can be dangerous. In fetuses, a teratoma can grow large enough to cause heart failure. But doctors may be able to remove it while the baby is still inside its mother.
You are listening to SCIENCE IN THE NEWS in VOA Special English.
The Pacific Ocean now has the world’s largest protected area for sea life. Earlier this month, President Bush established the Northwestern Hawaiian Islands Marine National Monument. It extends for more than three hundred sixty thousand square meters.
The area is home to about seven thousand kinds of sea life. Many are found nowhere else. Ten islands, atolls and other landforms are in the newly protected area northwest of the main islands of Hawaii. The president noted that the area is larger than forty-six of the fifty states.
He said the waters of the Northwestern Hawaiian Islands will now receive the nation's highest form of marine environmental protection. The action calls for an end to commercial fishing in those waters over a five-year period.
The declaration will limit visitors in most areas, but will provide for educational and scientific activities. It will also provide for cultural activities by Native Hawaiians. The National Oceanic and Atmospheric Administration will enforce the rules.
Other presidents over the years have taken steps to protect the area. Almost one hundred years ago, Theodore Roosevelt declared much of Hawaii a national wildlife refuge. And, in recent times, Bill Clinton ordered additional protections.
President Bush used a law passed by Congress a century ago. The National Antiquities Act lets the president take immediate action to protect important cultural or natural resources.
A plan to declare the area a national marine sanctuary could have taken a year. And sanctuaries do not ban fishing except in special areas.
Mister Bush signed the measure during a ceremony at the White House. The guests included Jean-Michel Cousteau. His father was the undersea explorer Jacques Cousteau.
Mister Bush had seen a film that the son produced about the Northwestern Hawaiian Islands and their environmental threats. He says it helped him decide to take the action he did.
Millions of seabirds live on the islands. So do the last of the severely endangered Hawaiian monk seals and most of the state's threatened green sea turtles.
Has anyone seen a large collection of very old earthen containers? They were stolen from the Moundville Archeological Park in Alabama in nineteen eighty. Two hundred sixty-four bowls, bottles and broken pieces of pottery are missing. Some objects date back to prehistoric times.
The Federal Bureau of Investigation has tried to find the artifacts. Not one piece of the collection is known to have been offered for sale. That leads some experts to believe all the objects are still together. Some people believe the artifacts have been taken out of the country.
The Moundville archeological area is along the Black Warrior River in central Alabama. The Native Americans who lived there made their pottery of earth hardened by fire. Some of the containers have handles. Some have artwork. Animals are shown on some of the artifacts. The animals are thought to have had religious meaning.
The stolen pottery represented twenty percent of the complete Moundville collection. The Alabama Museum of Natural History kept the artifacts in the Erskine Ramsay Archeological Repository. Experts say the best artifacts were stolen.
The area is called Moundville because people built twenty-six small hills of earth around a large public square. One mound, known as Mound A, may have supported the home of the chief. The chief ruled the city-state apparently with total control.
Experts say the settlement was occupied from one thousand years ago to five hundred fifty years ago. Archeologists discovered public buildings and many small houses. People were buried under some of the floors.
The community was a political and religious center overlooking the river and protected by huge wooden walls. About ten thousand people are believed to have lived in the settlement and nearby areas.
The warm climate and spring flooding in the lowlands of the Black Warrior River made the land fertile for growing maize.
The first archeology at Moundville did not result from work by a trained scientist. Instead, the first investigator was a wealthy man from Philadelphia, Pennsylvania.
For twenty years, Clarence Moore explored the southeastern United States in his steamboat. He explored the Black Warrior River area in nineteen-oh-five. A year later, he returned with a crew and began to dig.
In nineteen thirty-eight, the Civilian Conservation Corps unearthed the major discovery of the Moundville community. The Corps was one of the New Deal programs created by President Franklin Roosevelt.
Many people had no jobs during the Great Depression. President Roosevelt put some to work on projects like saving historic places.
From the findings at Moundville, scientists learned that the people did artistic work in pottery, stonework and copper.
Vernon Knight works for the Alabama Museum of Natural History. He says the Moundville society seemed to do well until about six hundred fifty years ago. At that time, Mister Knight says, Moundville stopped looking like a community. But it still was used as a political and ceremonial center. After that, however, the society seemingly lost importance.
Moundville was largely unoccupied by the fifteen hundreds. No one knows why. So two mysteries remain. What happened to the people? And where are their stolen artifacts?
SCIENCE IN THE NEWS was written by Nancy Steinbach, Erin Schiavone and Jerilyn Watson. If you missed any of our show, you can read a transcript and download audio at voaspecialenglish.com. I'm Bob Doughty.
And I'm Pat Bodnar. To send us e-mail, write to email@example.com. We hope you can join us again next week for more news about science in Special English on the Voice of America.
Correction: An earlier version of this page contained the sentence: "What works in humans does not always work in animals." It should have read: "What works in animals does not always work in humans."