VOA慢速英语2012 SCIENCE IN THE NEWS - American Scientists Create The World's First Genetically Engineered Monkeys

SCIENCE IN THE NEWS - American Scientists Create The World's First Genetically¹ Engineered Monkeys

CHRISTOPHER CRUISE: This is SCIENCE IN THE NEWS, in VOA Special English. I’m Christopher Cruise.

JUNE SIMMS: And I’m June Simms. Today, we tell about the creation of what are being called the world’s first genetically engineered monkeys. We also hear from American physicists². They are working to find the sub-atomic particle known as the Higgs boson. And we tell how rising levels of carbon dioxide are changing the chemistry of the oceans.

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CHRISTOPHER CRUISE: Scientists have created monkeys from cells taken from different embryos⁴. Experts at the Oregon National Primate⁵ Research Center believe the animals are the world’s first genetically engineered monkeys. The Center is part of the Oregon Health and Science University.

The scientists combined up to six rhesus monkey embryos to produce three animals. The embryos were placed into female rhesus monkeys.

A single monkey and twins were born last year. Their tissues and organs contain cells that come from each of the embryos used in the “mix.” The animals are now about nine months old. An official at Oregon National Primate Research Center has said they are in good health and growing normally.

JUNE SIMMS: Shoukhrat Mitalipov was the lead writer of a report about the event. The report appeared last month in the journal, “Cell.”

The new monkeys are called chimeric⁶ monkeys or chimeras⁸. In ancient Greece, a chimera⁷ was said to be a frightening-looking creature. Its body contained parts from more than one animal. But the chimera monkeys born last year look like other monkeys.

Professor Mitalipov says the monkey-producing experiment tested the possibilities of creating stem cells from embryos in laboratories. Stem cells have already been used to treat some conditions in human beings.

CHRISTOPHER CRUISE: Researchers produced the first chimeric animals in the nineteen sixties. At that time, work with mouse embryos showed the embryos could be joined to form one normal-sized mouse. Using these mice, scientists have been able to study conditions like heart disease, diabetes⁹ and Parkinson‘s disease. Since then, researchers have made chimeric rats, rabbits, sheep and cattle.

Efforts to make more complex mammals had failed until recent times. The Mitalipov team succeeded with the rhesus monkey embryos because of embryonic¹⁰ cells called totipotent cells. They can divide and produce all the different cells in the body of the organism. They also can produce the cells in the placenta, the tissue that connects the embryo³ to the mother.

JUNE SIMMS: Totipotent cells were responsible for creation of the whole animal, not just other living tissues. In the process, stem cells were injected into an embryo when it was still in early development. The embryo grew into a chimeric animal. This showed that the stem cells became part of the animal’s tissues and organs.

Shoukhrat Mitalipov said stem cells hold great promise for replacing damaged nerve cells. He noted¹¹ the possibilities for helping¹² patients who have lost ability to move and breathe from spinal¹³ cord injuries.

Creating chimera monkeys required a lot of work. But South American monkeys called marmosets are naturally chimeric. Marmoset mothers almost always produce twins – two babies developed from separate eggs.

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CHRISTOPHER CRUISE: Late last year, scientists reported they are one step closer to finding the sub-atomic particle called Higgs boson. The announcement came from scientists at the CERN laboratory in Switzerland. They announced results of experiments with the Large Hadron Collider. It is the world’s most powerful particle accelerator.

High-energy physicists hope the collider will give them an idea of what happened at the beginning of the universe. This is how the machine works. Using a lot of electricity, scientists spin atoms around a huge underground tunnel at close to the speed of light. Then, the atoms hit each other with great force. This causes the atoms to break into even smaller pieces. These pieces are what physicists want to study.

JUNE SIMMS: CERN’s Large Hadron Collider is just a few years old. But information gathered from the experiments has excited scientists in the United States.

University of Florida professor Jacobo Konigsberg has been active in CERN’s hunt for Higgs boson, also called the “God particle.” He says finding it would uncover one of the biggest mysteries of physics.

Professor Konigsberg has been studying the results of experiments at the Fermi National Laboratory near Chicago, Illinois. He says the recent announcement identified an area where the Higgs boson is likely to exist, if it exists at all.

CHRISTOPHER CRUISE: Another scientist at Fermilab, Robert Roser, welcomed the announcement, but still had many questions. Mr. Roser visited the CERN laboratories in the days leading up to the announcement.

Still, the development demonstrates the power of the Large Hadron Collider. It is more famous than Fermilab’s Tevatron Accelerator, which suspended operations last September.

For thirty years, American scientists used the Tevatron to search for the sub-atomic particle. However, there is a still a chance the device could produce the results scientists are looking for. Robert Roser and his team are still studying information from earlier tests. They expect to release their findings in March.

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JUNE SIMMS: Many scientists say carbon emissions¹⁴ are a major reason for rising temperatures in Earth’s atmosphere. Carbon emissions can come from automobiles¹⁵, buildings and factories. Most of these gases go into the atmosphere. But about thirty percent end up in the oceans. This makes seawater more acidic.

New research suggests that too much carbon dioxide in the oceans is creating a serious threat to sea life. Ocean acidity¹⁶ levels differ naturally from place to place and from one year to the next. This makes it difficult for scientists to show how much human activities are responsible for carbon emissions.

In a recent study, scientists looked back at twenty-one thousand years of climate history for information. Their findings were reported in the journal Nature Climate Change.

CHRISTOPHER CRUISE: Tobias Friedrich is a post-doctoral fellow at the University of Hawaii International Pacific Research Center.

TOBIAS FRIEDRICH: “The idea was that atmospheric¹⁷ carbon dioxide concentration increased from the Last Glacial Maximum to preindustrial times. This, of course, also had an effect on acidity levels in the ocean, and just to compare this naturally occurring increase in atmospheric carbon dioxide concentrations with man-made emissions over the last, let’s say two-hundred years.”

The scientists used computer models with information from ice and the ocean floor to recreate ocean conditions. Earth’s temperatures started to rise about seventeen thousand years ago, at the end of the last ice age. When that happened, carbon dioxide levels in the atmosphere began to rise. Over the next six thousand years, it grew from one hundred ninety parts per million to two hundred eighty parts per million. Sea creatures and their environment had time to react to the changing conditions.

JUNE SIMMS: Axel Timmerman also works at the University of Hawaii International Pacific Research Center. He says the record over the past two hundred years tells a different story.

AXEL TIMMERMAN: “Starting with the pre-industrial revolution, of course, the anthropogenic (human) emissions increased so much that the oceans suddenly started to take up huge amounts of carbon.”

Carbon dioxide levels in the atmosphere now stand at three hundred ninety-two parts per million. Mr. Timmerman says that has resulted in dangerously high levels of ocean acidification in some areas. And he says this is happening at a much faster rate.

AXEL TIMMERMAN: “Compared to the last glacial period, the rate of change is about two orders of magnitude faster than what occurred during the last major reorganization of the carbon cycle, about twenty to fifteen thousand years ago.”

CHRISTOPHER CRUISE: Ocean acidification could have been discovered much earlier. But scientists only began to measure it about thirty years ago. Combined with pollution and warming temperatures, it is a serious threat to ocean life. Acidification reduces the availability of carbonate. That is the mineral many shellfish and corals use to form their shells and skeletons. Axel Timmerman says the study gives decision-makers another tool for measuring the threat and finding ways to fight it.

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JUNE SIMMS: This SCIENCE IN THE NEWS was written by Brianna Blake and Jerilyn Watson. I’m June Simms.

CHRISTOPHER CRUISE: And I’m Christopher Cruise. Listen again next week for more news about science, in Special English, on the Voice of America.

1 genetically   

adv.遗传上

参考例句：

• All the bees in the colony are genetically related. 同一群体的蜜蜂都有亲缘关系。
• Genetically modified foods have already arrived on American dinner tables. 经基因改造加工过的食物已端上了美国人的餐桌。 来自英汉非文学 - 生命科学 - 基因与食物

2 physicists   

物理学家( physicist的名词复数 )

参考例句：

• For many particle physicists, however, it was a year of frustration. 对于许多粒子物理学家来说，这是受挫折的一年。 来自英汉非文学 - 科技
• Physicists seek rules or patterns to provide a framework. 物理学家寻求用法则或图式来构成一个框架。

3 embryo   

n.胚胎，萌芽的事物

参考例句：

• They are engaging in an embryo research.他们正在进行一项胚胎研究。
• The project was barely in embryo.该计划只是个雏形。

4 embryos   

n.晶胚；胚，胚胎( embryo的名词复数 )

参考例句：

• Somatic cells of angiosperms enter a regenerative phase and behave like embryos. 被子植物体细胞进入一个生殖阶段，而且其行为象胚。 来自辞典例句
• Evolution can explain why human embryos look like gilled fishes. 进化论能够解释为什么人类的胚胎看起来象除去了内脏的鱼一样。 来自辞典例句

5 primate   

n.灵长类（目）动物，首席主教；adj.首要的

参考例句：

• 14 percent of primate species are highly endangered.14%的灵长类物种处于高度濒危状态。
• The woolly spider monkey is the largest primate in the Americas.绒毛蛛猴是美洲最大的灵长类动物。

6 chimeric   

adj.妄想的，荒诞不经的

参考例句：

• High-intensity-type chimeric hedging may be gas-tight syringe safety connections, never loose. 高强度嵌合式套头，可与针筒安全气密式连接，绝不松脱。 来自互联网
• His utopia is not as chimeric commonwealth but a practical improvement on what already exists. 他的乌托邦不是空想的联邦，而是对那些已经存在的联邦实际改进。 来自互联网

7 chimera   

n.神话怪物；梦幻

参考例句：

• Religious unity remained as much a chimera as ever.宗教统一仍然和从前一样，不过是个妄想。
• I am fighting against my chimera.我在与狂想抗争。

8 chimeras   

n.（由几种动物的各部分构成的）假想的怪兽( chimera的名词复数 )；不可能实现的想法；幻想；妄想

参考例句：

• He was more interested in states of mind than in "puerile superstitions, Gothic castles, and chimeras." 他乐于描写心情，而不愿意描写“无聊的迷信，尖拱式的堡垒和妖魔鬼怪。” 来自辞典例句
• Dong Zhong's series, in its embryonic stage, had no blossoms, birds or surreal chimeras. 董重的这个系列的早年雏形并没有梅花、鸟和超现实的连体。 来自互联网

9 diabetes   

n.糖尿病

参考例句：

• In case of diabetes, physicians advise against the use of sugar.对于糖尿病患者，医生告诫他们不要吃糖。
• Diabetes is caused by a fault in the insulin production of the body.糖尿病是由体內胰岛素分泌失调引起的。

10 embryonic   

adj.胚胎的

参考例句：

• It is still in an embryonic stage.它还处于萌芽阶段。
• The plan,as yet,only exists in embryonic form.这个计划迄今为止还只是在酝酿之中。

11 noted   

adj.著名的，知名的

参考例句：

• The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
• Jim is noted for arriving late for work.吉姆上班迟到出了名。

12 helping   

n.食物的一份&adj.帮助人的，辅助的

参考例句：

• The poor children regularly pony up for a second helping of my hamburger. 那些可怜的孩子们总是要求我把我的汉堡包再给他们一份。
• By doing this, they may at times be helping to restore competition. 这样一来, 他在某些时候,有助于竞争的加强。

13 spinal   

adj.针的，尖刺的，尖刺状突起的；adj.脊骨的，脊髓的

参考例句：

• After three days in Japan,the spinal column becomes extraordinarily flexible.在日本三天，就已经使脊椎骨变得富有弹性了。
• Your spinal column is made up of 24 movable vertebrae.你的脊柱由24个活动的脊椎骨构成。

14 emissions   

排放物( emission的名词复数 )； 散发物（尤指气体）

参考例句：

• Most scientists accept that climate change is linked to carbon emissions. 大多数科学家都相信气候变化与排放的含碳气体有关。
• Dangerous emissions radiate from plutonium. 危险的辐射物从钚放散出来。

15 automobiles   

n.汽车( automobile的名词复数 )

参考例句：

• When automobiles become popular,the use of the horse and buggy passed away. 汽车普及后，就不再使用马和马车了。 来自《简明英汉词典》
• Automobiles speed in an endless stream along the boulevard. 宽阔的林荫道上，汽车川流不息。 来自《现代汉英综合大词典》

16 acidity   

n.酸度，酸性

参考例句：

• This plant prefers alkaline soil,though it will readily tolerate some acidity.这种植物在酸性土壤中也能生存，但硷性土壤更加适宜。
• Gastric acidity would not prevent the organism from passing into the gut.胃的酸度不能防止细菌进入肠道。

17 atmospheric   

adj.大气的，空气的；大气层的；大气所引起的

参考例句：

• Sea surface temperatures and atmospheric circulation are strongly coupled.海洋表面温度与大气环流是密切相关的。
• Clouds return radiant energy to the surface primarily via the atmospheric window.云主要通过大气窗区向地表辐射能量。