Factory farming could soon enter a new era of mass production. Companies in the USare developing the technology needed to "clone" chickens on a massive scale¹. Once a chicken with desirable traits has been bred or genetically engineered², tens of thousands of eggs, which will hatch into identical copies³ , could roll off the production lines every hour. Billions of clones could be produced each year to supply chicken farms with birds that all grow at the same rate, have the same amount of meat and taste the same.

    This, at least, is the vision of theUS"s National Institute of Science and Technology, which has given Origen Therapeutics of Burlingame, California, and Embrex of North Carolina $4.7 million to help fund research4. The prospect has alarmed animal welfare groups, who fear it could increase the suffering of farm birds.

    That"s unlikely to put off5 the poultry industry, however, which wants disease-resistant birds that grow faster on less food. "Producers would like the same meat quantity but to use reduced inputs to get there," says Mike Fitzgerald of Origen. To meet this demand, Origen aims to "create an animal that is effectively a clone", he says. Normal cloning doesn"t work in birds because eggs can"t be removed and implanted. Instead, the company is trying to bulk-grow6, embryonic stem cells7 taken from fertilized eggs as soon as they"re laid. "The trick is to culture8 the cells without them starting to distinguish, so they remain pluripotent," says Fitzgerald.

    Using a long-established technique, these donor cells will then be injected into the embryo of a freshly laid, fertilized recipient egg9, forming a chick that is a "chimera". Strictly speaking a chimera isn"t a clone, because it contains cells from both donor and recipient. But Fitzgerald says it will be enough if, say, 95 percent of a chicken"s body develops from donor cells. "In the poultry world, it doesn"t matter if it"s not 100 percent," he says.

    Another challenge for Origen is to scale up10 production. To do this, it has teamed up with11 Embrex, which produces machines that can inject vaccines into up to 50,000 eggs12 an hour. Embrex is now trying to modify the machines to locate the embryo and inject the cells into precisely the right spot without killing it.

    In future, Origen imagines freezing stem cells from different strains of chicken13. If orders come in for a particular strain, millions of eggs could be produced in months or even weeks. At present, maintaining all the varieties the market might call for is too expensive for breeders, and k takes years to breed enough chickens to produce the billions of eggs that farmers need.

词汇:

Clone/ kləʊn /n. & v.克隆，无性繁殖

embryo / ˈembriəʊ /n.胚胎

implant / "ɪmplɑ:nt /v.植入；移植

chimera / kaɪˈmɪərə /n.嵌合体

embryonic / ˌembriˈɒnɪk /adj.胚胎的

fertilise / "fɜ:tɪlaɪz /v.使受精

pluripotent / plʊə"rɪpətənt /adj.多能的

vaccine / "væksi:n /n.疫苗

注释：

1. on a massive scale:大规模
2. genetically engineered：经过基因改造。genetical engineering：遗传工程
3. hatch into identical copies：孵出如出一辙的（小）鸡
4. help fund research： 资助研究。fund用作动词，research是它的宾语。
5. put off：意为 “discourage”（使……气馁）。
6. bulk-grow： 大量繁殖
7. stem cell：干细胞
8. culture：动词，意思是：培育。
9. a freshly laid, fertilized recipient egg:新产下的；已受精的；要接受细胞植入的鸡蛋
10. scale up： 提高，按比例增加。
11. team up with：与 合作。
12. up to 50,000 eggs：多达 5 万只鸡蛋。
13. different strains of chicken：不同品种的鸡。

The technology of freezing stem cells from different strains of chicken can do all the followingEXCEPT that____．

A:farmers can order certain strains of chicken only B:Origen can supply all the strains of chicken the market might need C:chicken farmers order certain strains of chicken for economic reasons D:chicken farmers can be supplied with whatever strain they need

Shortages of flu vaccine are nothing new in America, but this year’s is a whopper. Until last week, it appeared that 100 million Americans would have access to flu shots this fall. Then British authorities, concerned about quality-control problems at a production plant in Liverpool, barred all further shipments by the Chiron Corp. Overnight, the U. S. vaccine supply dwindled by nearly half and federal health officials found themselves making an unusual plea. Instead of beseeching us all to get vaccinated, they’re now urging most healthy people between the ages of 2 and 64 not to. "This reemphasizes the fragility of our vaccine supply," says Dr. Martin Myers of the National Network for Immunization Information, "and the lack of redundancy in our system."
Why is such a basic health service so easily knocked out Mainly because private companies have had little incentive to pursue it. To create a single dose of flu vaccine, a manufacturer has to grow live virus in a 2-week-old fertilized chicken egg, then crack the egg, harvest the virus and extract the proteins used to provoke an immune response. Profit margins are narrow, demand is fickle and, because each year’s flu virus is different, any leftover vaccine goes to waste. As a result, the United States now has only two major suppliers (Chiron and Aventis Pasteur)—and when one of them runs into trouble, there isn’t much the other can do about it. "A vaccine maker can’t just call up and order 40 million more fertilized eggs, " says Manon Cox, of Connecticut-based Protein Sciences Corp. "There’s a whole industry that’s scheduled to produce a certain number of eggs at. a certain time."
Sleeker technologies are now in the works, and experts are hoping that this year’s fiasco will speed the pace of innovation. The main challenge is to shift production from eggs into cell cultures—a medium already used to make most other vaccines. Flu vaccines are harder than most to produce this way, but several biotech companies are now pursuing this strategy, and one culture-based product (Solvay Pharmaceuticals’ Invivac) has been cleared for marketing in Europe.
For Americans, the immediate challenge is to make the most of a limited supply. The government estimates that 95 million people still qualify for shots under the voluntary restrictions announced last week. That’s nearly twice the number of doses that clinics will have on hand, but only 60 million Americans seek out shots in a normal year. In fact, many experts are hoping the shortage will serve as an awareness campaign—encouraging the people who really need a flu shot to get one.
From the last paragraph we can infer that ______.

A:the government hopes to solve the problem by way of volunteer restrictions B:more than 47 million Americans who are qualified to get flu vaccine shots can not get them this year C:America has to deal with a limited supply of flu vaccines this year D:normally only a small percentage of American population gets flu vaccine shots each year

This vaccine is egg - based. What if I’m allergic to eggs
You should avoid the vaccine. If you’re in a high - risk group and you come down with the flu, see your doctor immediately. Antiviral medications, given within 24 to 48 hours of the onset of symptoms, can dramatically improve one’s outcome.
The vaccine should avoid application to a person who

A:is allergic to eggs. B:is in a high - risk group. C:has come down with the flu. D:has symptoms of the flu.

In 1976 more than 500 people contracted an autoimmune disease called Guillain - Barresyndrome after receiving swine - flu shots in response to a small outbreak in Fort Dix, N. J. Some people understandably fear a repeat of that tragic episode, However, vaccine, production techniques have changed since then. Today, vaccines are highly purified to eliminate any potential contaminants. In addition, scientists use only selected viral proteins in the shots, not the entire virus, as they did in the 1970s. "The public is comparing this vaccine to the 1976 swine--flu vaccine," says CDC spokesperson Abbigail Tumpey. "In fact, the best comparison is to the seasonal vaccines of the last ten years. "
Nowadays ,vaccines are highly purified to

A:remove people’s fear for vaccine. B:avoid repeating the tragic episode in 1976. C:get rid of any possible contaminants. D:improve vaccine -production techniques.

Vice Vaccines At first glance, vice vaccines look just great. These injections promise to inactivate drugs such as cocaine, heroin and nicotine in the bloodstream before they reach the brain. Without the "hit", people just won’’t come back for more. It’’s true that these vaccines are still being developed, so their full risks and benefits are not yet clear. But all the signs are that for people who are in danger of overdosing, or for addicts who want to get themselves clean but need some help to overcome their craving, the vaccines will be immensely valuable. But like many new technologies, they also bring difficult choices. Will convicted criminals who steal to feed their drug habit be allowed back onto the street if they agree to be vaccinated, for example? Could a judge even compel these people to be vaccinated? Perhaps the most controversial debate that vice vaccines have raised is whether they should be given routinely to children, like polio or measles vaccines. This is. not a distant worry. No sooner they have found themselves submerged with requests from worried parents who want their children vaccinated. Is this really what we want for future generations? For any society that values personal freedom, the answer has to be no. People have the right to choose how to behave, whether it’’s good or bad, legal or not. Let not ignore the fact that millions of people take illegal drugs for pleasure without becoming addicted. Administering vice vaccines will mean that youngsters are no longer free to make such choices for themselves. It would be like a return to Pleasantvile. And, remember, we’’re just talking about illegal drugs here. One vaccine under development acts against nicotine, and if its nicotine today, why not caffeine tomorrow? Society’’s attitudes to drugs change. Forty years ago, smoking was fine. A century ago, American ship operators were giving stevedores (码头工人) cocaine to speed up their work. Like it or not, people have been taking mind-altering chemicals since before recorded history. Each vaccine acts only against a specific drug, and stopping people getting high on one drug will simply push them to take others—as addiction researchers have already found. So drug use won’’t go away, the drugs will just change. Opposing the widespread use of vice vaccines for youngsters is not to advocate drug use. By all means let vice vaccines spark a revolution in detox (解毒) clinics. But when it comes to helping children deal with drugs, the way to help them is through education, ensuring that they can follow lifestyles that are incompatible with drug taking, and giving them the tools to spot risks and make informed choices. The problem of drug abuse is bound up with modern society in complex ways. Simple chemical solutions are unlikely to provide the whole answer. According to the writer, one of the disadvantages of vice vaccine is that______.

A:the vaccine cannot act against nicotine B:stevedores will not like it C:one vaccine can act against only a specific drug D:it will spark a revolution in the detox clinics

Vice Vaccines At first glance, vice vaccines look just great. These injections promise to inactivate drugs such as cocaine, heroin and nicotine in the bloodstream before they reach the brain. Without the "hit", people just won’’t come back for more. It’’s true that these vaccines are still being developed, so their full risks and benefits are not yet clear. But all the signs are that for people who are in danger of overdosing, or for addicts who want to get themselves clean but need some help to overcome their craving, the vaccines will be immensely valuable. But like many new technologies, they also bring difficult choices. Will convicted criminals who steal to feed their drug habit be allowed back onto the street if they agree to be vaccinated, for example? Could a judge even compel these people to be vaccinated? Perhaps the most controversial debate that vice vaccines have raised is whether they should be given routinely to children, like polio or measles vaccines. This is. not a distant worry. No sooner they have found themselves submerged with requests from worried parents who want their children vaccinated. Is this really what we want for future generations? For any society that values personal freedom, the answer has to be no. People have the right to choose how to behave, whether it’’s good or bad, legal or not. Let not ignore the fact that millions of people take illegal drugs for pleasure without becoming addicted. Administering vice vaccines will mean that youngsters are no longer free to make such choices for themselves. It would be like a return to Pleasantvile. And, remember, we’’re just talking about illegal drugs here. One vaccine under development acts against nicotine, and if its nicotine today, why not caffeine tomorrow? Society’’s attitudes to drugs change. Forty years ago, smoking was fine. A century ago, American ship operators were giving stevedores (码头工人) cocaine to speed up their work. Like it or not, people have been taking mind-altering chemicals since before recorded history. Each vaccine acts only against a specific drug, and stopping people getting high on one drug will simply push them to take others—as addiction researchers have already found. So drug use won’’t go away, the drugs will just change. Opposing the widespread use of vice vaccines for youngsters is not to advocate drug use. By all means let vice vaccines spark a revolution in detox (解毒) clinics. But when it comes to helping children deal with drugs, the way to help them is through education, ensuring that they can follow lifestyles that are incompatible with drug taking, and giving them the tools to spot risks and make informed choices. The problem of drug abuse is bound up with modern society in complex ways. Simple chemical solutions are unlikely to provide the whole answer. According to the writer, one of the disadvantages of vice vaccine is that______.

A:the vaccine cannot act against nicotine B:stevedores will not like it C:one vaccine can act against only a specific drug D:it will spark a revolution in the detox clinics