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When, in the age of automation, man searches for a worker to do the tedious, unpleasant jobs that are impossible to mechanize, he may very profitably consider the ape.If we tackled the problem of breeding for brains with as much as enthusiasm as we devote to breeding dogs of surrealistic shapes, we could eventually produce assorted models of useful primates, ranging in size from the gorilla down to the baboon, each adapted to a special kind of work. It is not putting too much strain on the imagination to assume that geneticists could produce a super-ape, able to understand some scores of words, and capable of being trained for such jobs as picking fruit, cleaning up the litter in parks, shining shoes, collecting garbage, doing household chores, and even baby-sitting (though I have known some babies I would not care to trust with a valuable ape).Apes could do many jobs, such as cleaning streets and the more repetitive types of agricultural work, without supervision, though they might need protection from those exceptional specimens of Homo sapiens who think it amusing to tease or bully anything they consider lower on the evolutionary ladder. For other tasks, such as delivering papers and laboring on the docks, our man-ape would have to work under human overseers; and, incidentally, I would love to see the finale of the twenty-first century version of the Waterfront in which the honest but hairy hero will drum on his chest after—literally taking the wicked labor leader apart.Once a supply of nonhuman workers becomes available, a whole range of low IQ jobs could be thankfully relinquished by mankind, to its great mental and physical advantage. What is more, one of the problems which has plagued so many fictional Utopias would be avoided: There would be none of the deridingly subhuman Epsilons of Huxley’s Brave New World to act as a permanent reproach to society, for there is a profound moral difference between breeding sub-men and super-apes, though the end products are much the same. The first would introduce a form of slavery, the second would be a biological triumph which could benefit both men and animals. The author of this article is （）
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Much of the research on hallucinogenic drugs such as LSD has focused on the neurotransmitter serotonin, a chemical that when released from a presynaptic serotonin-secreting neuron causes the transmission of a nerve impulse across a synapse to an adjacent postsynaptic, or target, neuron. There are two major reasons for this emphasis. First, it was discovered early on that many of the major hallucinogens have a molecular structure similar to that of serotonin. In addition, animal studies of brain neurochemistry following administration of hallucinogens invariably reported changes in serotonin levels.Early investigators correctly reasoned that the structural similarity to the serotonin molecule might imply that LSD’ s effects arc brought about by an action on the neurotransmission of serotonin in the brain. Unfortunately, the level of technical expertise in the field of brain research was such that this hypothesis had to be tested or, peripheral tissue ( tissue outside the brain). Two different groups of scientists reported than LSD powerfully blockaded serotonin’ s action, their conclusions were quickly challenged, however. We now know that the action of a drug at one site in the body does not necessarily correspond to the drug’ s action at another site, especially when one site is in the brain and the other is not.By the 1960’ s technical advances permitted the direct testing of the hypothesis that LSD and related hallucinogens act by directly suppressing the activity of serotonin secreting neurons themselves—the so called presynaptic hypothesis. Researchers reasoned that if the hallucinogenic drags act by suppressing the activity of serotonin-secreting neurons, then drugs administered after these neurons had been destroyed should have no effect on behavior, because the system would already be maximally suppressed. Contrary to their expectations, neuron destruction enhanced the effect of LSD and related hallucinogens on behavior. Thus hallucinogenic drugs apparently do not act directly on serotonin-secreting neurons.However, these and other available data do support an alternative hypothesis, that LSD and related drugs act directly at receptor sites on serotonin target neurons (the postsynaptic hypothesis). The fact that LSD elicits "serotonin syndrome", that is, causes the same kinds of behaviors as does the administration of serotonin in animals whose brains are depleted of serotonin indicates that LSD acts directly on serotonin receptors, rather than indirectly through the release of stores of serotonin. The enhanced effect of LSD reported after serotonin depletion could be due to a proliferation of serotonin receptor sites on serotonin target neurons. This phenomenon often follows neuron destruction or neurotransmitter depletion; the increase in the number of receptor sites appears to be a compensatory response to decreased input. Significantly, this hypothesis is supported by number of different laboratories, It can be inferred that researchers abandoned the presynaptic hypothesis because（）
数据并发操作通常会带来3类问题，它们是丢失更新、 【10】 和读脏数据。
在广域网中，T1标准规定的速率为______。
数据通信是在20世纪60年代随着______技术的不断发展和广泛应用而发展起来的一种新的通信技术。
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