单选题There are only three available strategies for controlling cancer: prevention, screening and treatment. Lung cancer causes more deaths than any other types of cancer. A major cause of the disease is not【C1】______known; there is no good evidence that screening is much help; and treatment fails in about 90 percent of all cases. At present, therefore, the main strategy must be【C2】______. This may not always be true, of course, as for some other types of cancer, researches over the past few decades have produced (or suggested) some importance in prevention, screening or treatment. 【C3】______, however, we consider not what researchers may one day offer but what today's knowledge could already deliver that is not being delivered, then the most practical and cost-efficient opportunities for avoiding premature death from cancer, especially lung cancer, probably involve neither screening nor improved【C4】______, but prevention. This conclusion does not depend on the unrealistic assumption that we can eliminate tobacco. It merely assumes that we can reduce cigarette sales appreciably by raising prices or by【C5】______on the type of education that already appears to have a positive effect on cigarette assumption by white-collar workers and that we can substantially reduce the amount of tar【C6】______per cigarette. The practicability of preventing cancer by such measures applies not only in those countries, such as, the United States of America, because cigarette smoking has been common for decades, 25 to 30 percent of all cancer deaths now involves lung cancer, but also in those where it has become【C7】______only recently. In China, lung cancer as yet accounts for only 5 to 10 percent of all cancer deaths. This is because it may take as much as half a century for the rise in smoking to increase in the incidence to lung cancer. Countries where cigarette smoking is only now becoming widespread can expect enormous increase in lung cancer during the 1990's or early in the next century, 【C8】______prompt effective action is taken against the habit—indeed, such increase is already plainly evident in parts of the world. There are reasons why the preventions of lung cancer is of such overwhelming importance. First, the disease is extremely common, causing more deaths than any other types of cancer now【C9】______: secondly, it is generally incurable; thirdly, effective, practicable measures to reduce its incidence are already reliably known; and finally, reducing tobacco consumption will also have a substantial【C10】______on many other diseases.

单选题Dry-cleaning machines that use liquid carbon dioxide as a solvent will go on sale in the US next year—thanks to chemists in North Carolina who have developed CO 2 -soluble detergents. Dry-cleaners will lose their characteristic smell, and the new process will cut the amount of toxic waste produced in cleaning clothes. Joseph DeSimone, a chemist at the University of North Carolina, Chapel Hill, says liquid CO 2 is an ideal solvent because after cleaning, the CO 2 can be evaporated off, collected, liquefied and reused. The problem in developing the process, says DeSimone, has been that CO 2 by itself is not a good solvent. However, he points out that not much dissolves in water without the help of detergents, yet water is the most common solvent. What CO 2 needed, he thought, was the right detergent. Detergent molecules such as those in washing-up liquid have two chemically distinct ends; one has a liking for water, the other sticks to dirt. Normal detergents do not dissolve in liquid CO 2 , so DeSimone created three CO 2 -soluble detergents. One end of the detergents has a fluorocarbon group, which makes them soluble in CO 2 . The other end is soluble in water, oil or silicone, depending on the type of dirt being removed. The person doing the dry-cleaning has to decide which of the detergents is best for the job. DeSimone"s company, MiCell, will start selling liquid CO 2 dry-Cleaning machines next year. They operate at room temperature at a pressure "about ten times the pressure of a bicycle tyro" , according to a spokesman for MiCell. Most dry-cleaners currently use chlorinated hydrocarbons such as perchloroethylene. But the US Environmental Protection Agency(EPA)is clamping down on the toxic waste emission this produces. After cleaning with the new machines, the liquid CO 2 is evaporated and collected for reuse, leaving a residue of detergent and dirt. Brad Lienhart, president of MiCell, says that cutting waste and pollution is the company" s strongest selling point. " Dry-cleaner owners are saying " get this burden off my back" ," he says. He hopes to sell a hundred machines, in the first year of business. About 15000 conventional drycleaning machines are sold around the world every year. Buster Bell, who owns Bell Laundry and Dry Cleaning in South Carolina, says the MiCell-technology looks competitive, and he likes the reduced environmental impact. "You really don"t know what is coming from the EPA," he says.

单选题Conventional wisdom about conflict seems pretty much cut and dried. Too little conflict breeds apathy(冷漠)and stagnation(呆滞). Too much conflict leads to divisiveness(分裂)and hostility. Moderate levels of conflict, however, can spark creativity and motivate people in a healthy and competitive way. Recent research by Professor Charles R. Schwenk, however, suggests that the optimal level of conflict may be more complex to determine than these simple generalizations. He studied perceptions of conflict among a sample of executives. Some of the executives worked for profit-seeking organizations and others for not-for-profit organizations. Somewhat surprisingly, Schwenk found that opinions about conflict varied systematically as a function of the type of organization. Specifically, managers in not-for-profit organizations strongly believed that conflict was beneficial to their organizations and that it promoted higher quality decision making than might be achieved in the absence of conflict. Managers of for-profit organizations saw a different picture. They believed that conflict generally was damaging and usually led to poor-quality decision making in their organizations. Schwenk interpreted these results in terms of the criteria for effective decision making suggested by the executives. In the profit-seeking organizations, decision-making effectiveness was most often assessed in financial terms. The executives believed that consensus rather than conflict enhanced financial indicators. In the not-for-profit organizations, decision-making effectiveness was defined from the perspective of satisfying constituents. Given the complexities and ambiguities associated with satisfying many diverse constituents executives perceived that conflict led to more considered and acceptable decisions.

单选题People from around the world flock to the United States expecting to find a better life. But to scientists" surprise, a growing body of evidence indicates that increasing familiarity with U. S. culture and society renders immigrants and their children far more susceptible to many mental and physical ailments, even if they attain financial success. The latest study of this phenomenon, directed by epidemiologist William A. Vega of the University of Texas, San Antonio, finds much higher rates of major depression, substance abuse, and other mental disorders in U. S. -born Mexican-Americans compared with both recent and long-standing Mexican-American immigrants. This pattern held regardless of education or income levels. Vega" s results appear at the same time as the release of a national report on declining physical and mental health in children of immigrant families. A panel convened by the National Research Council and the Institute of Medicine, both in Washington, D. C. ,reviewed previous studies and concluded that assimilation into a U. S. lifestyle may undermine the overall health of immigrant children much more than being poor does. In contrast, studies of nonimmigrant U. S. residents usually link poverty to poor physical and mental health. " The material on immigrant health shocked me when we first reviewed it," says panel member Arthus M Kleinman, a psychiatrist and anthropologist at Harvard Medical School in Boston. " Vega " s study is consistent with the panel" s conclusion that immigrants" health deteriorates with assimilation to U.S. society, declining toward general U. S. norms. " says Kleinman. Other studies have indicated that citizens of many countries, including Mexico, are healthier overall than U. S. citizens. Vega"s team interviewed 3,012 adults of Mexican origin, ages 18-59, living Fresno County, Calif. Of that number, 1,810 people identified themselves as immigrants. Interviews were in English or Spanish. Interviewers expressed an interest in health issues only and tried to minimize any tendency of participants to lie—due to U. S. residency concerns—about having immigrated. Nearly one-half of U. S. -born Mexican-Americans had suffered from at least one of 12 psychiatric disorders at some time in their lives, compared with only one-quarter of the immigrants. Common mental conditions in U. S. -born individuals included major depression, phobias and other anxiety disorders, and substance abuse and dependence. Prevalence rates for mental disorders were lowest for those who had immigrated within the past 13 years. The higher rates found among immigrants of 13 or more years still fell considerably below those for the native-born group.

单选题Children are getting so fat they may be the first generation to die before their parents, an expert claimed yesterday. Today's youngsters are already falling prey to potential killers such as diabetes because of their weight. Fatty fast-food diets combined with sedentary lifestyles dominated by televisions and computers could mean kids will die tragically young, says Professor Andrew Prentice, from the London School of Hygiene and Tropical Medicine. At the same time, the shape of the human body is going through a huge evolutionary shift because adults are getting so fat. Here in Britain, latest research shows that the average waist size for a man is 36~38in and may be 42~44in by 2032. This compares with only 32. 6in in 1972. Women's waists have grown from an average of 22 inches in 1920 to 24 inches in the Fifties and 30 inches now. One of the major reasons why children now are at greater risk is that we are getting fatter younger. In the UK alone, more than one million under-16s are classed as overweight or obese — double the number in the mid-Eighties. One in ten four-year-olds are also medically classified as obese. The obesity pandemic—an extensive epidemic—which started in the US, has now spread to Europe, Australia, Central America and the Middle East. Many nations now record more than 20 per cent of their population as clinically obese and well over half the population as overweight. Prof Prentice said the change in our shape has been caused by a glut of easily available high-energy foods combined with a dramatic drop in the energy we use as a result of technology developments. He is not alone in his concern. Only last week one medical journal revealed how obesity was fuelling a rise in cancer cases. Obesity also increases the risk factor for strokes and heart disease. An averagely obese person's lifespan is shortened by around nine years while a severely obese person by many more. Prof Prentice said: "So will parents outlive their children, as claimed recently by an American obesity specialist?" The answer is yes—and no. Yes, when the offspring become grossly obese. This is now becoming an alarmingly common occurrence in the US. Such children and adolescents have a greatly reduced quality of life in terms of both their physical and psychosocial health. So say No to that doughnut and burger.

单选题WHY SHOULD anyone buy the latest volume in the ever-expanding Dictionary of National Biography? I do not mean that it is bad, as the reviewers will agree. But it will cost you 65 pounds. And have you got the rest of volumes? You need the basic 22 plus the largely decennial supplements to bring the total to 31. Of course, it will be answered, public and academic libraries will want the new volume. After all, it adds 1,068 lives of people who escaped the net of the original compilers. Yet in 10 year"s time a revised version of the whole caboodle, called the New Dictionary of National Biography, will be published. Its editor, Professor Colin Matthew, tells me that he will have room for about 50,000 lives, some 13,000 more than in the current DNB. This rather puts the 1,068 in Missing Persons in the shade. When Dr. Nicholls wrote to The Spectator in 1989 asking for name of people whom readers had looked up in the DNB and had been disappointed not to find, she says that she received some 100,000 suggestions.(Well, she had written to her quality newspapers" too.)As soon as her committee had whittled the numbers down, the professional problems of an editor began. Contributors didn"t file copy on time; some who did sent too much: 50,000 words instead of 500 is a record, according to Dr. Nicholls. There remains the dinner-party game of who"s in, who"s out. That is a game that the reviewers have played and will continue to play. Criminals were my initial worry. After all, the original edition of the DNB boasted: Malefactors whose crimes excite a permanent interest have received hardly less attention than benefactors. Mr. John Gross clearly had similar anxieties, for he complains that, while the murderer Christie is in, Crippen is out. One might say in reply that the injustice of the hanging of Evans instead of Christie was a force in the repeal of capital punishment in Britain, as Ludovie Kennedy(the author of Christies entry in Missing Persons)notes. But then Crippen was reputed as the first murderer to be caught by telegraphy(he had tried to escape by ship to America). It is surprising to find Max Miller excluded when really not very memorable names get in. There has been a conscious effort to put in artists and architects from the Middle Ages. About their lives not much is always known. Of Hugo of Bury St Edmunds, a 12th-century illuminator whose dates of birth and death are not recorded, his biographer comments: "Whether or not Hugo was a wall-painter, the records of his activities as carver and manuscript painter attest to his versatility". Then there had to be more women, too(12 percent, against the original DBN"s 3), such as Roy Strong"s subject, the Tudor painter Levina Teerlinc, of whom he remarks: "Her most characteristic feature is a head attached to a too small, spindly body. Her technique remained awkward, thin and often cursory". Doesn"t seem to qualify her as a memorable artist. Yet it may be better than the record of the original DNB, which included lives of people who never existed(such as Merlin)and even managed to give thanks to J. W. Clerke as a contributor, though, as a later edition admits in a shamefaced footnote, "except for the entry in the List of Contributors there is no trace of J. W. Clerke".

单选题Can electricity cause cancer? In a society that literally runs on electric power, the very idea seems preposterous. But for more than a decade, a growing band of scientists and journalists has pointed to studies that seem to link exposure to electromagnetic fields with increased risk of leukemia and other malignancies. The implications are unsettling, to say the least, since everyone comes into contact with such fields, which are generated by everything electrical, from power lines and antennas to personal computers and micro-wave ovens. Because evidence on the subject is inconclusive and often contradictory, it has been hard to decide whether concern about the health effects of electricity is legitimate—or the worst kind of paranoia. Now the alarmists have gained some qualified support from the U. S. Environmental Protection Agency. In the executive summary of a new scientific review, released in draft form late last week, the EPA has put forward what amounts to the most serious government warning to date. The agency tentatively concludes that scientific evidence "suggests a casual link" between extremely low-frequency electromagnetic fields — those having very longwave-lengths — and leukemia, lymphoma and brain cancer, While the report falls short of classifying ELF fields as probable carcinogens, it does identify the common 60-hertz magnetic field as "a possible, but not proven, cause of cancer in humans". The report is no reason to panic—or even to lost sleep. If there is a cancer risk, it is a small one. The evidence is still so controversial that the draft stirred a great deal of debate within the Bush Administration, and the EPA released it over strong objections from the Pentagon and the White House. But now no one can deny that the issue must be taken seriously and that much more research is needed. At the heart of the debate is a simple and well-understood physical phenomenon: When an electric current passes through a wire, it generates an electromagnetic field that exerts forces on surrounding objects. For many years, scientists dismissed any suggestion that such forces might be harmful, primarily because they are so extraordinarily weak. The ELF magnetic field generated by a video terminal measures only a few milligauss, or about one-hundredth the strength of the earth's own magnetic field. The electric fields surrounding a power line can be as high as 10 kilovolts per meter, but the corresponding field induced in human cells will be only about 1 millivolt per meter. This is far less than the electric fields that the cells themselves generate. How could such minuscule forces pose a health danger? The consensus used to be that they could not, and for decades scientists concentrated on more powerful kinds of radiation, like X-rays, that pack sufficient wallop to knock electrons out of the molecules that make up the human body. Such "ionizing" radiations have been clearly linked to increased cancer risks and there are regulations to control emissions. But epidemiological studies, which find statistical associations between sets of data, do not prove cause and effect. Though there is a body of laboratory work showing that exposure to ELF fields can have biological effects on animal tissues, a mechanism by which those effects could lead to cancerous growths has never been found. The Pentagon is far from persuaded. In a blistering 33-page critique of the EPA report, Air Force scientists charge its authors with having "biased the entire document" toward proving a link. "Our reviewers are convinced that there is no suggestion that electromagnetic fields present in the environment induce or promote cancer, " the Air Force concludes. "It is astonishing that the EPA would lend its imprimatur on this report. " Then Pentagon's concern is understandable. There is hardly a unit of the modern military that does not depend on the heavy use of some kind of electronic equipment, from huge ground-based radar towers to the defense systems built into every warship and plane.

单选题The U. S. may so far have enjoyed good luck in escaping a direct SARS hit, but officials aren" t leaving anything to chance. The best hope for averting a SARS epidemic at home will be to keep SARS out at the nation" s borders. Federal immigration laws authorize immigration authorities to exclude non-citizens who are determined to have a "communicable disease of public health significance". Immigration law also authorizes the President by proclamation to suspend the entry of any group of aliens whose entry he deems to be detrimental to the interests of the United States. This little-used power could be deployed to exclude all aliens from affected areas, a policy Taiwan has recently implemented. Under the Public Health Service Act, any individual(citizens included)may be quarantined at an international port of entry if they are reasonably believed to be carrying a designated communicable disease. As of an April 4 Executive Order by President Bush, SARS is now a designated disease. Thus, in tandem with airline screening, federal health authorities are carefully monitoring travelers from affected areas in Asia for SARS symptoms. With an estimated 25 ,000 individuals entering the country legally from Asia on a daily basis, that is a tall order. A single SARS-infected person getting through the net could bring down the border strategy. The U. S. government might also reinforce the border strategy through restrictions on travel by American citizens to affected areas. In a series of Cold War era decisions, the Supreme Court upheld international travel restrictions for national security reasons, and one can imagine the same rationale applying to a public health emergency. How practical it would be to prohibit—and police—a travel ban to countries such as China is another question. The initial SARS defense, then, hinges on effective border control. But U. S. borders are far from under control. There are an estimated 8~9 million undocumented aliens now in the United States, a figure growing by as many as 500,000 per year. Asia is the largest contributor to undocumented immigration outside the western hemisphere, funneling illegal aliens into the United States through elaborate smuggling networks. SARS could just as easily make serious inroads into the U. S. through this backdoor rather than the front.

单选题Osteoporosis used to be called "the silent disease" because its victims didn' t know they had it until it was too late and they suffered a bone fracture. Today, doctors can identify osteoporosis early. Improved understanding of the disease has also led to new treatments and strategies for preventing the disease altogether. For post-menopausal women, the most common medical response to osteoporosis is hormone replacement therapy. Boosting estrogen levels strengthens the entire skeleton and reduces the risk of hip fracture. Unfortunately, it sometimes causes uterine bleeding and may increase the risk of breast cancer. To bypass such side effects, researchers have developed several alternative treatments. Synthetic estrogens called Selective Estrogen Receptor Modulators (SERMs) emulate estrogen with slight modifications. Another drug, alendronate, reduces spine, hip and wrist fractures by 50 percent. Researchers have even developed a nasal spray called calcitonin. Each of these alternatives has trade-offs, however. Patients must talk with their doctors to decide which therapy is best for them. The ideal way to address osteoporosis is by adopting a healthy lifestyle. And the best time to do this is in childhood, when most bone mass is accumulated. Because bodies continue building bone until about age thirty, some experts believe that women in their twenties can still increase their bone strength by as much as 20 percent. Calcium, which is available in low-fat dairy foods and dark green vegetables, is essential for preventing osteoporosis. So is vitamin D, which aides calcium absorption. Vitamin D comes from sunlight, but dietary supplements may be helpful in northern climates and among those who don't get outside. The final component is regular moderate exercise because bone responds to the needs that the body puts on it. These are the simple steps that can help make "the silent disease" truly silent.

单选题The discovery of the Antarctic not only proved one of the most interesting of all geographical adventures, but created what might be called "the heroic age of Antarctic exploration". By their tremendous heroism, men such as Shackleton, Scott, and Amundsen caused a new continent to emerge from the shadows and yet that heroic age, little more than a century old, is already passing. Modern science and inventions are revolutionizing the techniques of former explorers, and, although still calling for courage and feats of endurance, future journey into these icy wastes will probably depend on motor vehicles equipped with caterpillar traction rather than on the dogs that earlier discoverers found so invaluable. Few realize that this Antarctic continent is almost equal in size to South America, and enormous field of work awaits geographers and prospectors. The coasts of this continent remain to be accurately charted, and the mapping of the whole of the interior presents formidable task to the cartographers who undertake the work. Once their labors are completed, it will be possible to prospect the vast natural resources which scientists believe will furnish one of the large treasure hoards of metals and minerals the world has yet known, and almost inexhaustible sources of copper, coal, uranium, and many other ores will become available to man. Such discoveries will usher in an era of practical exploitation of the Antarctic wastes. The polar darkness which hides this continent for the six winter months will be defeated by huge batteries of light, and make possible the establishing of airfields for the future intercontinental air service by making these areas as light as day. Present flying routes will completely change, for the Antarctic refueling bases will make flight from Australia to South America comparatively easy over the 5 000 miles journey. The climate is not likely to offer an insuperable problem, for the explorer Admiral Byrd has shown that the climate is possible even for men completely untrained for expeditions into those frozen wastes. Some of his party were men who had never seen snow before, and yet he records that they survived the rigors of the Antarctic climate comfortably, so that, provided that the appropriate installations are made, we may assume that human beings from all countries could live there safely. Byrd even affirms that it is probably the most health climate in the world, for the intense cold of thousands of years has sterilized this continent, and rendered it absolutely germfree, with the consequences that ordinary and extraordinary sicknesses and disease from which man suffers in other zones with different climates are here utterly unknown. There exist no problems of conservation and preservation of food supplies, for the latter keep indefinitely without any signs of deterioration; it may even be that later generations will come to regard the Antarctic as the natural storehouse for the whole world. Plans are already on foot to set up permanent bases on the shores of this continent, and what so few years ago was regarded as a " dead continent" now promises to be a most active centre of human life and endeavor.

单选题Allelomimetic behavior may be defined as behavior in which two or more individual animals do the same thing, with some degree of mutual simulation and coordination. It can only involve in species with sense organs that are well enough developed so that continuous sensory contact can be maintained. It is found primarily in vertebrate, in those species that are diurnal, and usually in those that spend much of their lives in the air, in open water or on open plains. In birds, allelomimetic behavior is the rule rather than the exception, though it may occasionally be limited to particular seasons of the year as it is in the redwing blackbird. Its principal function is that of providing safety from predators, partly because the flock can rely on many pairs of eyes to watch for enemies, and partly because if one bird reacts to danger, the whole flock is warned. Among mammals, allelomimetic behavior is very rare in rodents, which almost never move in flocks or herds. Even when they are artificially crowded together, they do not conform in their movements. On the other hand, such behavior is a major system among large hoofed mammals such as sheep. In the pack-hunting carnivores, allelomimetic behavior has another function that of cooperative hunting for large prey animals such as moose. Wolves also defend their dens as a group against larger predators, such as bears. Finally, allelomimetic behavior is highly developed among most primate groups, where it has the principal function of providing warning against predators, though combined defensive behavior is also seen in troops of baboons.

单选题A TIME columnist bears witness to an operation to help triplets with cerebral palsy walk like other boys. Cindy Hickman nearly bled to death the day she gave birth — three months prematurely — to her triplet sons. Weighing less than 2 lbs. each, her babies were alive, but barely. They clung so tenuously to life that her doctors recommended she name them A, B and C. Then, after a year of heroic interventions —brain shunts, tracheotomies, skull remodeling — often requiring emergency helicopter rides to the hospital nearest their rural Tennessee home, the Hickmans learned that their triplets had cerebral palsy. Fifteen years ago there wasn"t much that could be done about cerebral palsy, a disorder caused by damage to the motor centers of the brain. But pediatric medicine has come a long way since then, both in intervention before birth, with better prenatal care and various techniques to postpone delivery, and surgical interventions after birth to correct physical deficiencies. So although the incidence of cerebral palsy seems to be increasing(because the odds of preemies surviving are so much better), so too are the number of success stories. This is one of them. Lane, Codie and Wyatt(as the Hickman boys are called)have spastic cerebral palsy, the most common form, accounting for nearly 80% of cases. "We first noticed that they weren"t walking when they should," Cindy recalls. "Instead they were only doing the combat crawl." Their brains seemed to be developing age appropriately, but their muscles were unnaturally stiff, making walking difficult if not impossible. Happily, spastic cerebral palsy is also the most treatable form of CP, largely thanks to a procedure known as selective dorsal rhizotomy, in which the nerve roots that are causing the problem are isolated and severed. Among the first to champion SDR in the U.S. in the late 1980s was Dr. T.S. Park, a Korean-born pediatric neurosurgeon at Washington University in St. Louis, Mo., who has preformed more than 800 of these operations and hopes to do an additional 1,000 before he retires. Peering through a microscope and guided by an electric probe, we were able to distinguish between the two groups of nerve roots leaving the spinal cord. The ventral roots send information to the muscle; the dorsal roots send information back to the spinal cord. The dorsal roots cause spasticity, and if just the right ones are severed, the symptoms can be greatly reduced. Nearly half a million Americans suffer from cerebral palsy. Not all are candidates for SDR, but Park estimates that as many as half may be. He gets the best results with children between ages 2 and 6 who were born prematurely and have stiffness only in their legs. He is known for performing the operation very high up in the spine, right where the nerve roots exit the spinal cord. It"s riskier that way, but the recovery is faster, and in Park"s skilled hands, the success rate is higher. Cindy and Jeremy Hickman will testify to that. Just a few weeks after the procedure, two of their sons are walking almost normally and the third is rapidly improving.

单选题Too much alcohol dulls your senses, but a study in Japan shows that moderate drinkers have a higher IQ than teetotalers. Researchers at the National Institute for Longevity Sciences in Aichi Prefecture, 250 kilometers west of Tokyo, tested the IQs of 2000 people between the ages of 40 and 79. They found that, on average, men who drank moderately—defined as less than 540 milliliters of sake or wine a day— had an IQ that was 3. 3 points higher that men who did not drink at all. Women drinkers scored 2. 5 points higher than female teetotalers. The type of alcohol didn" t influence the results. The volunteers tried a variety of tipples, which ranged from beer and whisky to wine and sake. The researchers are quick to point out that the results do not necessarily show that drinking will make you more intelligent. " It" s very difficult to show a cause-effect relationship," says senior researcher Hiroshi Shi-mokata. "We screened subjects for factors such as income and education, but there may be other factors such as lifestyle and nutritional intake. " Shimokata says that people who drink sake, or Japanese rice wine, tend to eat more raw fish. This could be a factor in enhanced intelligence, as fish often contain essential fatty acids that have been linked to brain development. Similarly, wine drinkers eat a lot of cheese, which is not something Japanese people normally consume or buy. Shimokata says the high fat content of cheese is thought to be good for the brain. If alcoholic drinks are directly influencing IQ, Shimokata believes chemicals such as polyphenols could be the critical factor. They are known to have antioxidant properties and other beneficial effects on ageing bodies, such as dilating constricted coronary arteries. The study is part of a wider research project to find out why brain function deteriorates with age.

单选题It was the kind of research that gave insight into how flu strains could mutate so quickly. (One theory behind the 1918 version's sudden demise after wreaking so much devastation was that it mutated to a nonlethal form. ) The same branch of research concluded in 2005 that the 1918 flu started in birds before passing to humans. Parsing this animal-human【C1】______could provide clues to【C2】______the next potential superflu, which already has a name: H5N1, also known as avian flu or bird flu. This potential killer also has a number: 59 percent. According to the World Health Organization, nearly three-fifths of the people who【C3】______H5N1 since 2003 died from the virus, which was first reported【C4】______humans in Hong Kong in 1997 before a more serious【C5】______occurred in Southeast Asia between 2003 and 2004. (It has since spread to Africa and Europe. ) Some researchers argue that those mortality numbers are exaggerated because WHO only【C6】______cases in which victims are sick enough to go to the hospital for treatment【C7】______compare that to the worldwide mortality rate of the 1918 pandemic; it may have killed roughly 50 million people, but that was only 10 percent of the number of people infected, according to a 2006 estimate. H5N1's saving grace — and the only reason we're not running around masked up in public right now — is that the strain doesn't jump from birds to humans, or from humans to humans, easily. There have been just over 600 cases (and 359 deaths) since 2003. But【C8】______its lethality, and the chance it could turn into something far more transmissible, one might expect H5N1 research to be exploding, with labs【C9】______the virus's molecular components to understand how it spreads between animals and【C10】______to humans, and hoping to discover a vaccine that could head off a pandemic.

单选题Vitamins and food-derived compounds are the focus of a large part of chemopreventive research, but a number of drugs being used for treatment may also be suitable for prevention. One such drug is tamoxifen, the anti-estrogen medication that has demonstrated great potency in the treatment of breast cancer. First synthesized in 1966 for birth-control research, tamoxifen is thought to thwart cancer by blocking estrogen receptors that, when occupied, stimulate cell proliferation. An on-going, 10-year study by a national collaborative group of US physicians and scientists and the National Cancer Institute is testing tamoxifen" s ability to prevent breast cancer in thousands of healthy women who are at increased risk for the disease. In earlier studies of breast cancer patients, tamoxifen reduced the incidence of new tumors in the unaffected breast by about 40 percent. Those figures providing the rationale for investigating tamoxifen as preventive agent. But although it has clearly been a boon to breast cancer patients, tamoxifen has side effects, the most serious of which are increased risks of uterine cancer and blood-clot formation. Because of those risks, some women" s health advocates have questioned the use of the compound by healthy women for prevention. Yet the knowledge gained from a large-scale preventive trial of tamoxifen could help researcher understand how to synthesize a second generation of anti-estrogen drugs having greater potency and fewer risks than those associated with tamoxifen itself. We have every reason to believe that the power of chemoprevention is sure to grow as researchers continue to identify promising new chemoprevention agents and clinical trials begin to provide insights into these substances" effects in humans. With the advance of these investigations and our greater understanding of cancer, chemoprevention will undoubtedly play a major role in reducing cancer incidence as well as the number of deaths caused by the disease.

单选题For years, scientists have been warning us that the radiation from mobile phones is detrimental to our health, without actually having any evidence to back these【C1】______up. However research now suggests that mobile phone radiation has at least one positive side effect it can help prevent Alzheimer's,【C2】______in the mice that acted as test subjects. It's been suspected, though never proven, that heavy use of mobile phone is bad for your health. It's thought that walking around with a cellphone permanently attached to the side of your head is almost sure to be【C3】______your brain. And that may well be true, but I'd rather wait until it's proven before giving up that part of my daily life. But what has now been proven, in a very perfunctory manner, is that mobile phone radiation can have an effect on your brain. 【C4】______in this case it was a positive rather than negative effect. According to BBC News, the Florida Alzheimer Disease Research Center conducted a study on 96 mice to see if the radiation given off by mobile phone could affect the onset of Alzheimer's. Some of the mice were "genetically altered to develop beta-amyloid plagues in their brains"【C5】______they aged. These are a marker of Alzheimer's. All 96 mice were then "exposed to the lector-magnetic【C6】______generated by a standard phone for two one-hour periods each day for seven to nine months. "The lucky things. 【C7】______, the experiment showed that the mice altered to be predisposed to dementia were protected from the disease if exposed before the onset of the illness. Their cognitive abilities were so unimpaired as to be virtually【C8】______to the mice not genetically altered in any way. Unfortunately, although the results are positive, the scientists don't actually know why exposed to mobile phone radiation has this effect. But it's hoped that further study and testing could result in a non-invasive【C9】______for preventing and treating Alzheimer's disease. Autopsies carried out on the mice also concluded no ill-effects of their exposure to the radiation. However the fact that the radiation prevented Alzheimer's means mobile phones【C10】______our brains and bodies in ways is not yet explored. And it's sure there are negatives as well as this one positive.

单选题Charles Paul and his wife, Hazel, stopped using the motor home they bought several years ago; it sits idle behind their house in Richardson, Texas. Travel is just one sacrifice they made to pay for the cost of their prescriptions, more than a dozen medications for the two of them. They found relief by switching drugstores, to one in nearby McKinney. A prescription for Paul" s diabetes had cost $ 89. 88 when he got it from a national chain but dropped down to $ 58 from McKinney" s Smith Drug. Smith, which claims to be the oldest drugstore in Texas, has been getting a lot of attention since a Dallas newspaper touted its astoundingly low prices. The overwhelming response from the public has been " a little scary," says co-owner Kaylei Mosier. She says the store simply marks each prescription up enough to cover its costs, but for many prescriptions that" s a lot lower than at other stores. The Smith Drug story has highlighted a little-known fact: prescription prices vary from city to city and block to block, and a little research can save consumers hundreds or thousands of dollars. Insurance copays can make these differences invisible, but they" re a huge deal to the 45 million uninsured Americans. Why the price swings? Howard Schiff, executive director of the Maryland Pharmacists Association , explains that pharmacies generally buy their drugs from a wholesaler, who doesn" t sell to every drugstore at the same price. Once the drug is in the pharmacy, each owner chooses how much to mark it up. Because fewer than 10 percent of consumers comparison-shop for prescriptions the way they might for a quart of milk—and drug prices generally are not advertised—pharmacies don" t worry that higher prices will drive people away, says Stanford economist Alan Scorensen. There is a downside to hopping from drugstore to drugstore. If people price-shop, they" re going to lose some protection that comes from having one pharmacy track all your medications. Going to many pharmacies keeps one pharmacist from noticing potentially harmful interactions between prescriptions. Comparison-shopping is further complicated because pharmacies that have the best price on one drug don" t usually have the lowest prices across the board, so finding a good price on one drug at a pharmacy does not guarantee a cheaper total bill.

单选题The injection that the girl had been given was beginning to work. Her head【C1】______heavy, and she was very sleepy. Once she opened her eyes and saw two nurses. They were placing her on another bed. Then she had the feeling of moving down a long hall. Once【C2】______a while, she thought that she heard people talking around her. The last time she opened her eyes, she saw a large round lamp above her. Then everything was dark, and she【C3】______into a deep sleep. The doctor was【C4】______to begin. First he opened the chest【C5】______around the heart. Meanwhile, another doctor connected the special machine to her. Next, the first doctor used an electric shock to stop the girl's heart. Working very carefully, he repaired the passage that was【C6】______. Then, using another electric shock, he【C7】______the heart again. He closed her chest, and the operation was【C8】______. No additional blood had been needed. The【C9】______operation lasted ninety minutes. The girl was taken to another room She would be watched until she was conscious. As she opened her eyes, the girl saw her mother's face. Her mother smiled. "It's all over, " she said. "The doctor promised to make you better and he has succeeded. In a few weeks you'll be【C10】______home. "

单选题Patients can recall what they hear while under general anesthetic even if they don"t wake up, concludes a new study. Several studies over the past three decades have reported that people can retain conscious or subconscious memories of thoughts that happened while they were being operated on. But failure by other researchers to confirm such findings has led skeptics to speculate that the patients who remembered these events might briefly have regained consciousness in the course of operations. Gitta Lubke, Peter Sebel and colleagues at Emory University in Atlanta measured the depth of anesthesia using bispectral analysis, a technique which measures changes in brainwave pattern in the frontal lobes moment by moment during surgery. "Before this study researchers only took an average measurement over the whole operation," says Lubke. Lubke studied 96 trauma patients undergoing emergency surgery. Many of whom were too seriously injured to tolerance full anesthesia. During surgery each patient wore headphones through which a series of 16 words was repeated for 3 minutes each. At the same time bisecteal analysis recorded the depth of anesthesia. After the operation Lubke tested the patients by showing them the first three letters of a word such as "limit", and asking them to complete. Patients who had had a word starting with these letters played during surgery — "limit", for example — chose that word an average of 11 per cent more often than patients who had been played a different word list. None of the patients had any conscious memory of hearing the word lists. Unconscious priming was strongest for words played when patients were most lightly anaesthetized. But it was statistically significant even when patients were fully anaesthetized when the word was played. This finding which will be published in the journal Anesthesiology could mean that operating theatre staff should be more discreet. "What they say during surgery may distress patient afterwards," says Philip Merikle, a psychologist at the University of Waterloo, Ontario.

单选题Can the Internet help patients jump the line at the doctor"s office? The Silicon Valley Employers Forum, a sophisticated group of technology companies, is launching a pilot program to test online "virtual visits" between doctors at three big local medical groups and about 8,000 employees and their families. The six employers taking part in the Silicon Valley initiative, including heavy hitters such as Oracle and Cisco Systems, hope that online visits will mean employees won"t have to skip work to tend to minor ailment or to follow up on chronic conditions. "With our long commutes and traffic, driving 40 miles to your doctor in your hometown can be a big chunk of time," says Cindy Conway, benefits director at Cadence Design Systems, one of the participating companies. Doctors aren"t clamoring to chat with patients online for free; they spend enough unpaid time on the phone. Only 1 in 5 has ever E-mailed a patient, and just 9 percent are interested in doing so, according to the research firm Cyber Dialogue. "We are not stupid," says Stirling Somers, executive director of the Silicon Valley Employers group. "Doctors getting paid is a critical piece in getting this to work." In the pilot program, physicians will get $ 20 per online consultation, about what they get for a simple office visit. Doctors also fear they"ll be swamped by rambling E-mails that tell everything but what"s needed to make a diagnosis. So the new program will use technology supplied by Healinx, an Alameda, Calif. -based start-up. Healinx"s "Smart Symptom Wizard" questions patients and turns answers into a succinct message. The company has online dialogues for 60 common conditions. The doctor can then diagnose the problem and outline a treatment plan, which could include E-mailing a prescription or a face to face visit. Can E-mail replace the doctor"s office? Many conditions, such as persistent cough, require a stethoscope to discover what"s wrong — and to avoid a malpractice suit. Even Larry Bonham, head of one of the doctor"s groups in the pilot, believes the virtual doctor"s visits offer a "very narrow" sliver of service between phone calls to an advice nurse and a visit to the clinic. The pilot program, set to end in nine months, also hopes to determine whether online visits will boost worker productivity enough to offset the cost of the service. So far, the Internet"s record in the health field has been underwhelming. The experiment is "a huge roll of the dice for Healinx," notes Michael Barrett, and analyst at Internet consulting from Forester Research. If the "Web visits" succeed, expect some HMOs(Health Maintenance Organizations)to pay for online visits. If doctors, employers, and patients aren"t satisfied, figure on one more E-health start-up to stand down.