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Of 100 billion nerve cells in the human brain, how many form after birth For years, the official answer was "zero". Scientists thought people were born with all the neurons they’d ever have. But from 1980s, biologists overturned that doctrine, finding a reservoir of stem cells that became fresh neurons in two parts of the brains of adult birds, monkeys and humans. Those discoveries were stunning, but the next seemed to top them all. In 1999, psychologist Elizabeth Gould reported large numbers of new nerve cells in a third of the monkey brain, hinting that the same part in humans—the neocortex, which lets us reason and remember—was regenerating, too. If she was right, scientists would have to revise almost all their ideas about human memory, and doctors might someday find a way to treat Alzheimer’s patients by simply turning on the neural-construction equipment. The birth of new nerve cells, or "neurogenesis", is now confirmed in the original two parts of human brain, the hippocampus and olfactory bulb. But for the neocortex, the no-neurons theory lives— and it’s just gotten major boost. Until December, Gould’s study stood alone and unverified. Two neuroscientists have repeated her work in Science, but not her results. Where Gould saw new nerve cells in the neocortex, Rakic and Konnack see only glial cells, the "glue" that supports neurons. But they do spot new nerve cells in the other two areas. In a January review in Nature Neuroscience, Rakic charges Gould’s work with technical problems. Focusing on what appeared to be 100 new neurons, Rakic and Kornack found that every one was merely a new glial cell hiding behind an old neuron. Gould has a cross-sectioned image from her own study that she says shows one cell marked as new—and it’s clearly a neuron. But Rakic has an answer for that, too. The method that identified the cells as "new" finds DNA synthesis, which can happen in cells that aren’t actually dividing. Rakic says Gould’s tests were too sensitive, tagging "new" neurons that weren’t. Gould responses that Rakic’s methods just weren’t sensitive enough. But even she can’t explain why that might be. Rakic’s study squares with the idea that memory cornes not from new nerve cells but from chemicals in the spaces between old ones. Gould’s team are circulating response to Rakic and Kornack and recreating two studies side by side to see if small differences in methods are to blame. Others are also redoing the tests; a Japanese team’s unpublished results echoes Rakic’s, while another team’s support Gould’s. Meanwhile work on less controversial new neurons marches forward. Neuroscientist Fred Gage, who’s just wrapped up a study of the function of new hippocampus nerve cells, says that’s as it should be. Still, until more studies confirm Rakic and Komack, he’ll keep a close eye on the neocortex debate. What was the problem with Gould’s research result according to Rakic
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Of 100 billion nerve cells in the human brain, how many form after birth For years, the official answer was "zero". Scientists thought people were born with all the neurons they’d ever have. But from 1980s, biologists overturned that doctrine, finding a reservoir of stem cells that became fresh neurons in two parts of the brains of adult birds, monkeys and humans. Those discoveries were stunning, but the next seemed to top them all. In 1999, psychologist Elizabeth Gould reported large numbers of new nerve cells in a third of the monkey brain, hinting that the same part in humans—the neocortex, which lets us reason and remember—was regenerating, too. If she was right, scientists would have to revise almost all their ideas about human memory, and doctors might someday find a way to treat Alzheimer’s patients by simply turning on the neural-construction equipment. The birth of new nerve cells, or "neurogenesis", is now confirmed in the original two parts of human brain, the hippocampus and olfactory bulb. But for the neocortex, the no-neurons theory lives— and it’s just gotten major boost. Until December, Gould’s study stood alone and unverified. Two neuroscientists have repeated her work in Science, but not her results. Where Gould saw new nerve cells in the neocortex, Rakic and Konnack see only glial cells, the "glue" that supports neurons. But they do spot new nerve cells in the other two areas. In a January review in Nature Neuroscience, Rakic charges Gould’s work with technical problems. Focusing on what appeared to be 100 new neurons, Rakic and Kornack found that every one was merely a new glial cell hiding behind an old neuron. Gould has a cross-sectioned image from her own study that she says shows one cell marked as new—and it’s clearly a neuron. But Rakic has an answer for that, too. The method that identified the cells as "new" finds DNA synthesis, which can happen in cells that aren’t actually dividing. Rakic says Gould’s tests were too sensitive, tagging "new" neurons that weren’t. Gould responses that Rakic’s methods just weren’t sensitive enough. But even she can’t explain why that might be. Rakic’s study squares with the idea that memory cornes not from new nerve cells but from chemicals in the spaces between old ones. Gould’s team are circulating response to Rakic and Kornack and recreating two studies side by side to see if small differences in methods are to blame. Others are also redoing the tests; a Japanese team’s unpublished results echoes Rakic’s, while another team’s support Gould’s. Meanwhile work on less controversial new neurons marches forward. Neuroscientist Fred Gage, who’s just wrapped up a study of the function of new hippocampus nerve cells, says that’s as it should be. Still, until more studies confirm Rakic and Komack, he’ll keep a close eye on the neocortex debate. What contribution was made by Gould to the research of nerve cells
The use of deferential (敬重的) language is symbolic of the Confucian ideal of the woman, which dominates conservative gender norms in Japan. This ideal presents a woman who withdraws quietly to the background, subordinating her life and needs to those of her family and its male head. She is a dutiful daughter, wife, and mother, master of the domestic arts. The typical refined Japanese woman excels in modesty and delicacy; she "treads softly (谨言慎行) in the world" elevating feminine beauty and grace to an art form. Nowadays, it is commonly observed that young women are not conforming to the feminine linguistic (语言的) ideal. They are using fewer of the very deferential "women’s" forms, and even using the few strong forms that are known as "men’s". This, of course, attracts considerable attention and has led to an outcry in the Japanese media against the defeminization of women’s language. Indeed, we didn’t hear about "men’s language" until people began to respond to girls’ appropriation of forms normally reserved for boys and men. There is considerable sentiment about the "corrnption" of women’s language —which of course is viewed as part of the loss of feminine ideals and morality—and this sentiment is crystallized by nationwide opinion polls that are regularly carried out by the media. Yoshiko Matsumoto has argued that young women probably never used as many of the highly deferential forms as older women. This highly polite style is no doubt something that young women have been expected to "grow into" —after all, it is a sign not simply of femininity, but of maturity and refinement, and its use could be taken to indicate a change in the nature of one’s social relations as well. One might well imagine little girls using exceedingly polite forms when playing house or imitating older women—in a fashion analogous to little girls’ use of a high-pitched voice to do "teacher talk" or "mother talk" in role play. The fact that young Japanese women are using less deferential language is a sure sign of change —of social change and of linguistic change. But it is most certainly not a sign of the "masculization" of girls. In some instances, it may be a sign that girls are making the same claim to authority as boys and men, but that is very different from saying that they are trying to be "masculine". Katsue Reynolds has argued that girls nowadays are using more assertive language strategies in order to be able to compete with boys in schools and out. Social change also brings not simply different positions for women and girls, but different relations to life stages, and adolescent girls are participating in new subcultural forms. Thus what may, to an older speaker, seem like "masculine" speech may seem to an adolescent like "liberated" or "hip" speech. How do some people react to women’s appropriation of men’s language forms as reported in the Japanese media
现在没有人知道中国的背包旅行现象(backpacker phenomenon)确切的渊源，不过成千上万的人已经加入到这种生态自助型的(eco-centric)新旅游活动中。而想要成为“驴友”(friend of donkey)，你不一定要年轻力强，也不一定要囊中富足。“驴友”们很多不过是口袋空空的(impoverished)学生，每一次旅途都需要精打细算，而另一些人则可能已到了中老年。有的人徒步到偏远的地方(remote places)泡上好几个月，有的在周末来一次远足，他们总是准备着探索旅程中新的道路，发现惊喜。
The use of deferential (敬重的) language is symbolic of the Confucian ideal of the woman, which dominates conservative gender norms in Japan. This ideal presents a woman who withdraws quietly to the background, subordinating her life and needs to those of her family and its male head. She is a dutiful daughter, wife, and mother, master of the domestic arts. The typical refined Japanese woman excels in modesty and delicacy; she "treads softly (谨言慎行) in the world" elevating feminine beauty and grace to an art form. Nowadays, it is commonly observed that young women are not conforming to the feminine linguistic (语言的) ideal. They are using fewer of the very deferential "women’s" forms, and even using the few strong forms that are known as "men’s". This, of course, attracts considerable attention and has led to an outcry in the Japanese media against the defeminization of women’s language. Indeed, we didn’t hear about "men’s language" until people began to respond to girls’ appropriation of forms normally reserved for boys and men. There is considerable sentiment about the "corrnption" of women’s language —which of course is viewed as part of the loss of feminine ideals and morality—and this sentiment is crystallized by nationwide opinion polls that are regularly carried out by the media. Yoshiko Matsumoto has argued that young women probably never used as many of the highly deferential forms as older women. This highly polite style is no doubt something that young women have been expected to "grow into" —after all, it is a sign not simply of femininity, but of maturity and refinement, and its use could be taken to indicate a change in the nature of one’s social relations as well. One might well imagine little girls using exceedingly polite forms when playing house or imitating older women—in a fashion analogous to little girls’ use of a high-pitched voice to do "teacher talk" or "mother talk" in role play. The fact that young Japanese women are using less deferential language is a sure sign of change —of social change and of linguistic change. But it is most certainly not a sign of the "masculization" of girls. In some instances, it may be a sign that girls are making the same claim to authority as boys and men, but that is very different from saying that they are trying to be "masculine". Katsue Reynolds has argued that girls nowadays are using more assertive language strategies in order to be able to compete with boys in schools and out. Social change also brings not simply different positions for women and girls, but different relations to life stages, and adolescent girls are participating in new subcultural forms. Thus what may, to an older speaker, seem like "masculine" speech may seem to an adolescent like "liberated" or "hip" speech. The first paragraph describes in detail ______.
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