쌍둥아빠의 티스토리

Scientists have mapped the genetic code of two kinds of cacao or cocoa tree, which provide the beans used to make chocolate

Scott Dorfman, an engineer at Organovo, working on the NovoGen bio-printer

BARBARA KLEIN: This is SCIENCE IN THE NEWS in VOA Special English. I'm Barbara Klein.

BOB DOUGHTY: And I'm Bob Doughty. Today, we will tell how technology could help doctors meet demand for transplant organs. We also will tell about a scientific effort to explain an event described in the holy books of three religions.

(MUSIC)

BARBARA KLEIN: Many people are waiting for an organ that could save or improve their lives. In the United States alone, more than one hundred thousand people are candidates for donated organs or tissue. The Organ Donor and Procurement Network supervises organ donation for the government. The private, not-for-profit group says only about fourteen thousand organs were donated in the first six months of this year.

Demand for new organs is far greater than supplies in the United States and other countries. Experts estimate that millions of people around the world need organ transplants.

BOB DOUGHTY: For years, doctors have wondered if there is another way. Researchers have been working to develop machines and processes that can create organs. The idea seems like something from a science fiction movie, but it is very real and showing early results.

In nature, some fish, lizards and worms can re-grow body parts. Replacing human organs is much more complex. Solid organs, like the liver, are dense with specialized cells. Some organs are very large. A human liver, for example, can weigh almost two kilograms. Still, it may be surprising to know that replacement organs have already been grown and successfully placed in patients.

BARBARA KLEIN: Doctor Anthony Atala is Director of the Institute for Regenerative Medicine at the Wake Forest University Baptist Medical Center. He produced new bladders for patients. His team created a base, or scaffolding, that provides a structure for growing cells. Researchers grow cells on the scaffolding, slowly building up tissue that becomes a working organ.

Doctor Atala described the process in a talk recorded by the arts and technology group TED.

ANTHONY ATALA: “We then take a scaffold that we shape like a bladder. We coat the inside with these bladder lining cells. We coat the outside with these muscle cells. We place it back into this oven-like device. From the time you take that piece of tissue, six to eight weeks later you can put the organ right back into the patient.”

BOB DOUGHTY: Growing new organs sounds like something for the distant future. Yet businesses are working on machines that can produce tissue and organs a lot like a photocopier copies documents.

K.C. Alfred/Union-Tribune

A “printed” blood vessel at Organovo lab in San Diego, California

One example is Organovo, a company in the American state of California. Organovo calls itself a regenerative medicine company. Its goal, the company says, is to use printing technology to create tissue for research and surgical operations.

Gabor Forgacs of the University of Missouri helped start Organovo in two thousand seven. This year, he appeared on a list of the one hundred most creative people in business by Fast Company, a business magazine.

BARBARA KLEIN: Last December, the Australia-based company Invetech reported that it had delivered the world’s first production model 3-D bio-printer for Organovo. Invetech plans to provide Organovo with several 3-D bio-printers by two thousand eleven. Organovo plans to place their machines at research centers around the world.

Organ printing is in many ways like other three-dimensional printing. The difference is that the printer builds a three-dimensional scaffolding out of a sugar-based material called a hydrogel. The scaffolding serves as the structure on which human cells grow. Different shaped scaffolding can produce blood vessels or other forms of tissue.

BOB DOUGHTY: Another part of the machine places cells at carefully measured positions on the scaffolding using lasers. The machine keeps the cells in conditions that let them grow into tissue and, in time, organs. Organovo calls this its NovoGen three-dimensional printing technology. Workers leave a container around the organ printing machinery to protect the tissue while it grows.

Organovo’s device is designed to “print” a new organ. The organ is then removed from the printer and prepared before a doctor places it in a patient. Some researchers believe that bio-printers may one day be able to print organs directly into the body.

(MUSIC)

BARBARA KLEIN: Three of the world’s major religions tell about the prophet Moses parting the Red Sea. The story says he directed the sea to divide so the ancient Israelites could reach the other side. The Israelites escaped slavery in Egypt by walking on dry land. Then the waters rose and flowed again. The waters returned and drowned the Egyptians chasing the Israelites.

The parting of the Red Sea appears in writings holy to Jews, Christians and Muslims. The three versions of the story differ in small ways, but the central information is the same. If true, it describes an event that took place more than three thousand years ago. The story says a strong east wind blew all night, and the sea parted in the morning.

Nicolle Rager Fuller

This illustration shows how a strong wind from the east could push back waters from two ancient basins -- a lagoon (left) and a river (right) -- to create a temporary land bridge

Scientists recently proposed a possible explanation for the division of Red Sea waters. A computer modeling study shows the event might have taken place where a river joined a coastal lagoon along the Mediterranean Sea. The study shows the wind might have pushed back both waterways. That could have made a pathway on the sea floor for Moses’ people to cross.

BOB DOUGHTY: Carl Drews of the University of Colorado at Boulder led the study. He also works for America's National Center for Atmospheric Research. A report on the study appeared in the Public Library of Science journal, PLoS One.

Mr. Drews examined information about likely places and depths of Nile River Delta waterways, which have moved over time. He says his results are what he called fairly close to the story in the Bible’s book of Exodus. He says the science of fluids in motion can explain the parting of the Red Sea. The wind moves the waters because of physical laws. This creates a safe passage with water on two sides. And later, he says, water can flow back in again.

The Red Sea is sometimes called the Sea of Reeds or the Reed Sea. The new study is part of a larger research project by Mr. Drews. The project explores the effects of winds on water depths. Its aim is to show how severe Pacific Ocean storms can cause storm surges. In a storm surge, seawater moves continuously. The water may reach a height of six meters or more.

BARBARA KLEIN: Other scientists have studied an event known as a wind setdown. Wind setdowns are a result of a strong wind that never seems to stop. Wind setdowns are the opposite of a storm surge. They can reduce water levels in one area while forcing water to build up in others. That is why some scientists say a wind setdown could have let the Israelites cross the Red Sea.

Russian scientists Alexei Androsov and Naum Voltzinger studied wind action in an earlier examination of the Red Sea crossing. They proposed conditions with winds blowing from the northwest at one hundred nineteen kilometers an hour. That is just under the wind-speed of a hurricane, a very severe ocean storm. The Russian scientists found the winds might possibly have uncovered an underwater reef close to where the Suez Canal is today.

However, Mr. Drews’ study found that the reef would have had to be completely flat for the water to run off in twelve hours. He and his research partner said the strong winds would have created a reef with even deeper channels. They do not believe that the Israelites could have walked across the Red Sea in winds of almost hurricane force.

BOB DOUGHTY: The two researchers found another possible place for the crossing. It is just south of the Mediterranean and about one hundred nineteen kilometers north of the Suez reef. They examined archeological records, satellite measurement and current maps. Then they estimated the water flow and depth that may have existed many centuries ago. They used a computer program to show what would happen with an overnight wind.

Mr. Drews said people have always wanted to know if the story of Moses parting the Red Sea comes from historical facts. He said his study shows that the description of the parting has a basis in physical laws.

(MUSIC)

BARBARA KLEIN: This SCIENCE IN THE NEWS was written by Mario Ritter and Jerilyn Watson. Our producer was June Simms. I'm Barbara Klein.

BOB DOUGHTY: And I'm Bob Doughty. Be listening again next week for more news about science in Special English on the Voice of America.

성공적인 기업의 평균 수명은 30년 이지만 

우리와 같은 지식근로자의 평균 근로 수명은 50년입니다. 
따라서 우리는 50년 동안 지속적으로 가치를 생산해 내는 능력이 필요합니다.
이 능력을 가진 사람은 학습과 경험을 통해 지속적으로 성장하며 가치를 만들어 낼 것입니다.

직장경력 5년 미만 
꾸준히 성실하게 배우십시오.  이 시기에는 계속해서 열심히 배우는 것이 중요합니다.
여러분이 어느 대학 어느 학과를 나왔는지는 중요하지 않습니다.
훌륭한 교수님에게 많은 것을 배웠겠지만...  
미안합니다. 여러분이 대학에서 배운 것은 취업과 동시에 과거의 지식이 되었습니다.
이제 여러분에게 필요한 진짜 기술은 새로운 것을 배우는 기술입니다.

직장경력 5년~10년차
이제 배우는 능력은 이미 갖추어져 있는 상태라고 칩시다.
이 시기에 중요한 것은 배운 것(지식)과 경험한 것을 합쳐서 지혜롭게 되는 것입니다.
꾸준히 가치를 만들어 내고 이것을 공유해야 합니다.
자신이 무엇을 잘 하고 무엇을 좋아하는지 알아야 합니다.
전공 따위는 잊어버려야 할 때입니다.
곧 새로운 진로에 대해 심각하게 고민해야 할 시기가 옵니다. 시간이 별로 없습니다.

직장경력 10년~15년차
자신의 전공이 자신의 자질과 별로 상관 없었다는 것을 알게 되는 시기입니다.
자신이 정말 좋아하는 것이 무엇인지 깨닫는 시기입니다.
직장생활 10년이 넘었지만 아직까지도 가치를 만들어 내는 능력이 부족하다면
믿기 어렵지만 슬슬 퇴직을 준비해야 합니다. 
그러나 만일 이 시기에 자신이 잘하는 것 좋아하는 것을 찾았다면
3~4년을 투자해 이 능력을 탁월하게 계발해야 합니다.
그러면 10년 정도 더 직장 생활을 할 수 있습니다.

여러분의 현재 지위가 무엇이건 경력이 몇 년이건 간에 지식 근로자의 유일한 가치는
가치를 생산해 내는 능력에 달려 있음을 기억하세요.
혹시나 주변에 있는 사람이 가치에 비해 더 높은 대우를 받고 있다면? 
억울하게 생각하지 말고 조금만 기다리시면 됩니다. 
조직 내에서 지속 가능성이 떨어지는 지식 근로자는 2~3년 안에 판별이 됩니다.

중요한 것은 가치를 생산하는 기술을 배우는 것입니다. 
계속 경험하는 것. 그리고 계속 지혜롭게 되는 것. 
이것이 지식근로자의 지속가능성입니다.

A sign advertises a medical marijuana provider in the Sherman Oaks area of Los Angeles

DOUG JOHNSON: Welcome to THIS IS AMERICA in VOA Special English. I'm Doug Johnson.

FAITH LAPIDUS: And I'm Faith Lapidus. This week on our program, we look at drug use and drug control policy in the United States.

(MUSIC)

DOUG JOHNSON: Last month, the government released its latest findings on illegal drug use in the United States.

GIL KERLIKOWSKE: "The report contains both good and bad news."

DOUG JOHNSON: Gil Kerlikowske heads the Office of National Drug Control Policy. He said the use of marijuana, ecstasy and methamphetamine all increased between two thousand eight and two thousand nine. So did the misuse of legal drugs like painkillers.

GIL KERLIKOWSKE: "Frankly, we are disappointed by these results. They represent a serious challenge to law enforcement, treatment, prevention and recovery communities and to parents."

DOUG JOHNSON: Mr. Kerlikowske said the good news was a decrease in the use of cocaine. He praised a partnership among the United States, Colombia and Mexico for helping to lower cocaine use by twenty-one percent since two thousand seven.

At the same time, though, a campaign launched by Mexico's president against traffickers has led to bloody drug wars. Groups in Mexico are fighting each other to meet American demand for drugs.

FAITH LAPIDUS: Each year the United States government surveys almost seventy thousand people throughout the country. The research is called the National Survey on Drug Use and Health. Among other things, people are asked if they have used illegal drugs within the past month.

In two thousand eight the survey found that eight percent of the population age twelve and older used illegal drugs. Last year that number increased by almost a full percentage point.

Officials said that was mainly the result of increases in the most commonly used illegal drug: marijuana. Use of marijuana increased by eight percent between two thousand eight and two thousand nine.

DOUG JOHNSON: Drug policy director Gil Kerlikowske says recent findings have suggested a softening in the concerns of young people about the risks of drugs. He says they see marijuana especially as less threatening than it seemed in the past. And he suggested some possible reasons.

GIL KERLIKOWSKE: "Some we cannot rule out are the constant discussions of so-called medical marijuana, marijuana legalization, and the downplaying of marijuana harms so prevalent in today’s media."

FAITH LAPIDUS: In California, though, a new state law reduces the offense for possessing a small amount of marijuana. Governor Arnold Schwarzenegger signed the bill into law on September thirtieth.

A person with less than twenty-eight grams will now be charged with an infraction instead of a misdemeanor. An infraction is the same level as a minor traffic violation.

The punishment will not change: violators cannot be jailed or fined more than one hundred dollars. But under the new law they will no longer have to worry about getting a criminal record.

Governor Schwarzenegger said California's finances were the main reason the Legislature changed the law.

DOUG JOHNSON: But the governor restated his opposition to a ballot measure that would legalize marijuana in California. Californians will vote on the measure, Proposition 19, during elections on November second.

Proposition 19 would permit the personal use of marijuana by people age twenty-one or older. It would also permit local governments to regulate and tax the production and sale of marijuana by businesses. But people would not be permitted to use marijuana in public or while children are present.

AP

An employee, behind the counter, helps clients choose from jars at a medical marijuana dispensary in Los Angeles

FAITH LAPIDUS: California is already one of nine western states that permit the use of marijuana to treat pain or for other medical purposes. So do Oregon, Washington state and Alaska, along with Colorado, Montana, Nevada, New Mexico and Hawaii.

Michigan in the Midwest and Maine, New Jersey, Rhode Island and Vermont in the East also permit some medical uses. Voters in the nation's capital just passed a medical marijuana law.

The laws differ. Most states require written documentation from a doctor about a patient's condition and need for treatment.

Some states only permit use for certain diseases like cancer, multiple sclerosis or AIDS. And rules differ about how patients can get the drug, how much they can possess and who can grow and sell it.

DOUG JOHNSON: California passed the nation's first medical-marijuana law in nineteen ninety-six. The state permits the use of marijuana for most medical conditions. Patients are not even required to get a written order from their doctor.

The law protects both the patient and the doctor from the risk of legal action. To follow the law, patients must get their marijuana only from officially recognized marijuana cooperatives and dispensaries.

FAITH LAPIDUS: Marijuana dispensaries and clubs need permission to operate under rules that are set by local officials.

The laws on medical marijuana in California are liberal -- some people say too liberal. Opponents say the dispensaries are nothing more than businesses that make big money selling marijuana.

DOUG JOHNSON: Officials in the city of Los Angeles have been taking action to shut down hundreds of dispensaries that are not legally registered. Patients argue that the closings make it difficult to get their marijuana as their doctors have advised.

But critics say the city has more than enough places to supply marijuana to patients. Neighbors of some operations suspect that not all the buyers have a real medical need.

FAITH LAPIDUS: Last year, the California Police Chiefs Association released a report on marijuana dispensaries in the state. The report listed problems that have been found outside some of these businesses. They include street robberies, drug sales to children and increased vehicle traffic.

DOUG JOHNSON: Mark Gustely is the owner of the Starbuds Cannabis Club in Santa Rosa, north of San Francisco. His store was robbed shortly after opening this year and he was hit on the head. Mr. Gustely says he has a better security system now.

He also says that before he opened his store, he did a lot of research into how other medical marijuana businesses operate.

MARK GUSTELY: "What I found is that the bulk of the growers do not keep any records, they refuse to allow anyone to see how they’re doing things. And we’ve structured our own store where each vendor, which out of nine hundred I've only got currently about ten approved, that are willing to allow their material to be inspected, allow their growth facility to be inspected and be verified organic or natural growing techniques. We also work with the customer to identify the strain that is most effective with the medical condition."

FAITH LAPIDUS: Last month, thirty-eight workers at a medical marijuana company in California joined the Teamsters -- one of America's oldest labor unions.

The workers are employed by a management company in Oakland for marijuana growing cooperatives. The workers approved a two-year contract that will provide retirement pay, higher wages and paid holidays. The company, Marjyn Investments, also agreed to pay for the workers' health care costs.

Lou Marchetti, local business agent for the Teamsters, says he never thought he would organize medical marijuana providers. "Never in my wildest dreams," he says. But he calls marijuana "an expanding industry in California."

DOUG JOHNSON: Dispensary owners are divided on Proposition 19 -- the ballot measure that would legalize marijuana in California.

Mark Gustely is against it. He says if marijuana is legalized, a state sales tax on top of a local tax would make medical marijuana too costly in dispensaries.

MARK GUSTELY: "Now, because it's been legalized, you are going to have a kid on the corner selling the same product for a lot less. And they’ll go buy it from some kid on the corner. Now, not everybody, but a number of people will, and this will generate this huge amount of disturbances in the community. There’ll be an outcry of 'Wow, this was a mistake, let's turn it over to a major corporation like the tobacco industry.'"

FAITH LAPIDUS: Critics of Proposition 19 also include former directors of the Office of National Drug Control Policy as well as the current director, Gil Kerlikowske.

They say there are some people who do not use marijuana simply for one reason -- because it is illegal. They predict that marijuana use will increase if voters in California take that reason away.

(MUSIC)

DOUG JOHNSON: President Obama chose Gil Kerlikowske to serve as the nation's so-called drug czar. The Senate confirmed him in May. Formerly, he was the police chief in Seattle, Washington, in the Pacific Northwest.

He supports drug policies aimed more at prevention and treatment than punishment. He says it makes no sense to keep talking about a "war on drugs."

GIL KERLIKOWSKE: "Nationally, overdose deaths have surpassed gunshot wounds as the number two cause of injury deaths. In sixteen states, drug-induced deaths have surpassed car crashes to become the leading cause of injury death."

Mr. Kerlikowske says filling jails with repeat drug offenders is not the answer. But he argues that legalizing drugs is not the solution either.

Others are not so sure. Bill Piper is the national affairs director of an organization called the Drug Policy Alliance.

BILL PIPER: "As long as drug use is a crime, people are going to be afraid to seek treatment. It's just not going to work."

FAITH LAPIDUS: The government is trying new ways to control drugs. An estimated seven million Americans abused prescription drugs last year.

The Drug Enforcement Administration just completed its first-ever "Prescription Drug Take-Back" campaign. The DEA set up more than four thousand places across the country on October second for people to leave medicines they no longer needed. The agency collected two hundred twenty thousand metric tons of prescription drugs. More take-back days are being planned for the future.

(MUSIC)

DOUG JOHNSON:Our program was written and produced by Caty Weaver. I’m Doug Johnson.

FAITH LAPIDUS: And I’m Faith Lapidus. You can comment on our programs at voaspecialenglish.com. Join us again next week for THIS IS AMERICA in VOA Special English.

Ben Sippel picks romaine lettuce for his business in Mount Gilead, Ohio in this file photo from 2007

This is the VOA Special English Agriculture Report.

Some people like to start their dinner with a salad of lettuce or other leafy greens. Ancient Egyptians and Romans also liked to have lettuce with their evening meal. But they served it at the end.

There are hundreds of kinds of head and leaf lettuces. The most popular ones include head lettuces such as iceberg, Boston, bibb and romaine.

Experts say lettuce is one of the easiest vegetables to grow in your garden. The best time to plant the seeds is during cool weather. Advisers at the University of Illinois Extension say the best planting temperature is fifteen degrees Celsius.

Lettuce seeds are small, so do not place them too deep in the ground. If you plant some seeds every week or two, you will have harvests ready to eat one after another.

You can use a seed tray to start the seeds indoors. The container should be deep enough to hold at least three centimeters of soil.

There should be about one centimeter of space between the soil and the top of the container. The container should have holes in the bottom so extra water can flow out.

Drop the seeds over the surface and cover them lightly with soil. If the soil is not already a little wet, give it some water. But not too much -- you do not want to drown the seeds.

Next, cover the seed tray with paper. Remove the paper when the seedlings have grown up far enough to touch it. You can transplant the seedlings into the garden when they are about two to three centimeters tall. Do this when the weather is not too hot and not too cold.

Take out as much of the soil as you can with the seedlings. Plant them in the ground in a hole that is bigger than the lettuce roots. Keep the plants watered, but not too heavily.

Harvest leaf lettuces when the leaves are big enough to eat. Pull the leaves from the outside of the planting so the inside leaves will keep growing.  Or, you can cut off the whole plant. Leave about two or three centimeters above the ground so the plant will re-grow. Cut off head lettuces at ground level.

Lettuce is best when served fresh. Store the remainder in the refrigerator in a plastic bag. It will last a few days and sometimes longer.

And that’s the VOA Special English Agriculture Report, written by Jerilyn Watson. Transcripts and podcasts of our reports are at voaspecialenglish.com. And captioned videos are on YouTube at VOA Learning English. I'm Faith Lapidus.

Stress increases during difficult economic times

Rare earth oxides from top center clockwise: praseodymium, cerium, lanthanum, neodymium, samarium, and gadolinium

This is the VOA Special English Economics Report.

Few people had ever heard of the natural elements known as rare earth metals before a recent dispute between China and Japan. Yet these metals are used in devices like smartphones, flat screens, hybrid car batteries, MP3 players and military equipment.

In September, Japan detained a Chinese ship captain near disputed islands in the East China Sea. China denied that it stopped exports of rare earth metals to Japan to force his release. But the incident raised concerns.

Japan is the world's biggest importer of rare earths. And China produces ninety-seven percent of the world supply.

China says it sold almost four billion dollars' worth in two thousand eight. But marketing professor George Haley at the University of New Haven in Connecticut says China has always kept prices low.

GEORGE HALEY: "So unlike other minerals, the price of rare earth elements, after the nineteen eighties when they started production, has actually fallen."

Some countries with rare earth metals no longer mine them -- including the United States. One reason is the low-cost imports from China. Another reason is concerns about environmental damage .

So what are these rare earth metals? Well, most of them are not rare; that is just their name. Several are more common than copper, lead or silver.

People who remember the periodic table of the elements from chemistry class might recognize them. Rare earths include the fifteen lanthanide metals along with yttrium and scandium.

Samuel Bader, a physicist at the Argonne National Laboratory near Chicago, says rare earths are often found together.

SAMUEL BADER: "They all have similar chemical properties.  Once you do find them, they are very difficult to separate from each other.”

But Mr. Bader explains that the same properties that make them hard to refine also make them valuable.

SAMUEL BADER: "Rare earth metals provide the world’s strongest commercial magnets. This is why they're important. It's that simple."

Rare earth magnets are lightweight and unaffected by conditions like high temperatures. So they work well in places like electric motors in hybrid vehicles or generators for wind turbines. Physicists use super-powerful magnets to speed particles and control radiation like X-rays.

And the list goes on, says George Haley, who has studied the subject.

GEORGE HALEY: "Electronics, fiber optics, you could go down the list of products important not just for the economic success of the United States, but for our defense and for our job creation here at home.”

Next week, we'll talk more about rare earth metals, and an American company that plans to start mining them again. And that's the VOA Special English Economics Report, written by Mario Ritter. And follow us on Facebook, Twitter, YouTube and iTunes at VOA Learning English.   I'm Jim Tedder.