阅读理解 Women do not avoid fighting because they are dainty or scared, but because they have a greater stake than men in staying alive to rear their offspring. Women compete with each other just as tenaciously as men, but with a stealth and subtlety that reduces their chances of being killed or injured, says Anne Campbell of the department psychology at the University of Durham. Across almost all cultures and nationalities, men have a much smaller role than women in rearing children. 'Males go for quantity of children rather than quality of care for offspring, which means that the parental investment of women is much greater,' says Campbell. And unlike men, who can't be sure that their children have not been fathered on the sly by other men, women can always be certain that half an offspring's genes are theirs. Women have therefore evolved a strong impulse than men to see their children grow up into adults. Men's psychological approach is geared to fathering as many children as possible. To make this strategy work and to attract partners, men need to establish and advertise their dominance over rival males. Throughout evolution this has translated into displays of male aggression, ranging in scale from playground fights to world wars. Men can afford to take more risks because as parents they are more expendable. Women, meanwhile, can only ensure reproductive success by overseeing the development of their children, which means avoiding death. 'The scale of parental investment drives everything,' says Campbell. 'It's not that women are too scared to fight,' she says. 'It's more to do with the positive value of staying alive, and women have an awfully big stake not just in offspring themselves but in offspring they might have in the future,' she says. This means that if women do need to compete—perhaps for a partner—they choose low-risk rules of engagement. They use indirect tactics, such as discrediting rivals by spreading malicious rumors. And unlike men who glory in feats of dominance, women do better by concealing their actions and their 'victories'. But there is no doubt, says Campbell, that the universal domination of culture by males has exaggerated these differences in attitudes to physical aggression. 'The story we've always been told is that females are not aggressive,' says Campbell. And when they are aggressive, women are told that their behavior is 'odd or abnormal'.

阅读理解 Less meat and dairy in our diets could help reduce agricultural greenhouse gases by as much as 80% by 2055, according to a recent study by the Potsdam Institute for Climate Impact Research (PIK). The researchers created global land-use model to project likely outcomes given different scenarios involving consumer dietary trends and changes in agriculture production methods. The models take into consideration population growth, the world economy, and other factors. The researchers found that, if meat and dairy consumption patterns remain constant of increase, the associated global agricultural omissions will increase significantly. On the other hand, a 25% reduction over the next 40 years would help bring levels to where they were around 1995. Methane and nitrous oxide in particular could be reduced if less meat and dairy is produced and consumed. These gases are caused largely by livestock waste and synthetic fertilizers. Around two-thirds of nitrous-oxide emissions come from agriculture—and most of that as a result of either raising animals or producing the feed used to raise them. Consumers' food choices, combined with what one PIK researcher terms 'technical mitigation options on the producers side' could make an enormous impact on these emissions. While not nearly as much methane or nitrous oxide is released into the atmosphere as carbon dioxide, both are significantly more potent and they form substantial pieces of the greenhouse gas pie. Both of these gases trap heat and radiation in the atmosphere much more effectively than does carbon dioxide. The U.S. Environmental Protection Agency cites methane as being '21 times more effective at trapping heat in the atmosphere than carbon dioxide over a 100-year time period.' Nitrous oxide is more than 300 times more effective than CO2. While the PIK study doesn't detail exactly which consumer choices and eating habits can help reverse the trend, it seems clear that less is more when it comes to consuming meat and dairy products.

阅读理解 Just because you're better educated doesn't mean that you're any more rational than everyone else, no matter how hard you may try to give that impression. Take the selection of lottery numbers. A survey in Florida described at this year's annual meeting of the American Association for the Advancement of Science shows that better educated people try to use random number systems to pick their lottery numbers. Despite the apparent logic of choosing random numbers, however, their chances of winning are no better than those of ordinary folk who use birthdays, anniversaries and other 'lucky' dates. Nor are they better off than those who draw on omens and intuitions, picking numbers seen on car number-plates and in dreams. But no doubt they feel a lot more rational. That appearance of 'rationality' may be a dangerous thing. Scientists are not immune to subtle and subjective influences on their judgments. Take the data from a survey of the public and member of the British Society Of Toxicology discussed at the same meeting. The survey showed that most people agree with the view that animals can be used to help predict how human will react, to chemicals, and that if a chemical causes cancer in an animal, we can be 'reasonably sure' it will cause cancer in humans. The toxicologists, however, are more circumspect. They accept the first statement but less likely to agree that if a chemical causes cancer in an animal, it will do so in a human. Can this difference be attributed to their expertise? Perhaps. But consider the considerable variation among toxicologists, those who were young, female, working in academia rather than industry or who felt that technology is not always used for the good of all, were more likely to agree that what causes cancer in an animal will cause cancer in a human. Maybe we need to think more about how who we are affects our 'rational' decisions.

阅读理解 If you are reading this article, antibiotics have probably saved your life—and not once but several times. A rotten tooth, a knee operation, a brush with pneumonia; any number of minor infections that never turned nasty. You may not remember taking the pills, so unremarkable have these one-time wonder drugs become. Modern medicine relies on antibiotics—not just to cure diseases, but to augment the success of surgery, childbirth and cancer treatments. Yet now health authorities are warning, in uncharacteristically apocalyptic terms, that the era of antibiotics is about to end. In some ways, bacteria are continually evolving to resist the drugs. But in the past we've always developed new ones that killed them again. Not this time. Infections that once succumbed to everyday antibiotics now require last-resort drugs with unpleasant side effects. Others have become so difficult to treat that they kill some 25,000 Europeans yearly. And some bacteria now resist every known antibiotic. Regular readers will know why: New Scientist has reported warnings about this for years. We have misused antibiotics appallingly, handing them out to humans like medicinal candy and feeding them to livestock by the tonne, mostly not for health reasons but to make meat cheaper. Now antibiotic-resistant bacteria can be found all over the world—not just in medical facilities, but everywhere from muddy puddles in India to the snows of Antarctica(南极洲). How did we reach this point without viable successors to today's increasingly ineffectual drugs? The answer lies not in evolution but economics. Over the past 20 years, nearly every major pharmaceutical company has abandoned antibiotics. Companies must make money, and there isn't much in short-term drugs that should be used sparingly. So researchers have discovered promising candidates, but can't reach into the deep pockets needed to develop them. This can be fixed. As we report this week, regulatory agencies, worried medical bodies and Big Phar-ma are finally hatching ways to remedy this market failure. Delinking profits from the volume of drug sold (by adjusting patent rights, say, or offering prizes for innovation) has worked for other drugs, and should work for antibiotics—although there may be a worryingly long wait before they reach the market. One day, though, these will fall to resistance too. Ultimately, we need, evolution-proof cures for bacterial infection: treatments that stop bacteria from causing disease, but don't otherwise inconvenience the little blighters. When resisting drugs confers no selective advantage, drugs will stop breeding resistance. Researchers have a couple of candidates for such treatment. But they fear regulators will drag their feet over such radical approaches. That, too, can be fixed. We must not neglect development of the sustainable medicine we need, the way we have neglected simple antibiotic R D. If we do, one day another top doctor will be telling us that the drugs no longer work—and there really will be no help on the way.

阅读理解 When it comes to health, which is more important, nature or nurture? You may well think your genes are a more important predictor of health and ill health. Not so fast. In fact, it transpires that our everyday environment outweighs our genetics, big time, when it comes to measuring our risk of disease. The genome is out—welcome the exposome. 'The exposome represents everything a person is exposed to in the environment, that's not in the genes,' says Stephen Rappaport, environmental health scientist at the University of California, Berkeley. That includes stress, diet, lifestyle choices, recreational and medicinal drug use and infections, to name a few. 'The big difference is that the exposome changes throughout life as our bodies, diets and lifestyles change,' he says. While our understanding of the human genome has been growing at an exponential rate over the last decade, it is not as helpful as we hoped in predicting diseases. 'Genes only contribute 10 percent to the overall disease burden,' says Rappaport. 'Knowing genetic risk factors can prove absolutely futile ,' says Jeremy Nicholson at Imperial College London. He points to work by Nina Paynter at the Brigham and Women's Hospital in Boston, who investigated the effect of 101 genetic markers implicated in heart disease. After following over 19,000 women for 12 years, she found these markers were not able to predict anything about the incidence of heart disease in this group. On the other hand, the impact of environmental influences is still largely a mystery.' There's an imbalance between our ability to investigate the genome and the environment,' says Chris Wild, director of the International Agency for Research on Cancer, who came up with the idea of the exposome. In reality, most diseases are probably caused by a combination of the two, which is where the exposome comes in. 'The idea is to have a comprehensive analysis of a person's full exposure history,' says Wild. He hopes a better understanding of exposures will shed a brighter light on disease risk factors. There are likely to be critical periods of exposure in development. For example, the time from birth to 3 years of age is thought to be particularly important. 'We know that this is the time when brain connections are made, and that if you are obese by this age, you'll have problems as an adult,' says Nicholson.

阅读理解 Have you switched off your computer? How about your television? Your video? Your CD player? And even your coffee percolator? Really switched them off, not just pressed the button on some control panel and left your machine with a telltale bright red light warning you that it is ready to jump back to life at your command? Because if you haven't, you are one of the guilty people who are helping to pollute the planet. It doesn't matter if you've joined the neighborhood recycling scheme, conscientiously sorted your garbage and avoided driving to work. You still can't sleep easy while just one of those little red lights is glowing in the dark. The awful truth is that household and office electrical appliances left on stand-by mode are gobbling up energy, even though they are doing absolutely nothing. Some electronic products—such as CD players—can use almost as much energy on stand-by as they do when running. Others may use a lot less, but as your video player spends far more hours on stand-by than playing anything, the wastage soon adds up. In the US alone, idle electronic devices consume enough energy to power cities with the energy needs of Chicago or London—costing consumers around $1 billion a year. Power stations fill the atmosphere with carbon dioxide just to do absolutely nothing. Thoughtless design is partly responsible for the waste. But manufacturers only get away with designing products that waste energy this way because consumers are not sensitive enough to the issue indeed, while recycling has caught the public imagination, reducing waste has attached much less attention. But 'source reduction', as the garbage experts like to call the art of not using what you don't need to use, offers enormous potential for reducing waste of all kinds. With a little intelligent shopping, you can cut waste long before you reach the recycling end of the chain. Packaging remains the big villain. One of the hidden consequences of buying products grown or made all around the world, rather than produced locally, is the huge amount of packaging needed to transport them safely. In the US, a third of the solid waste collected from city homes is packaging. To help cut the waste and encourage intelligent manufacturers the simplest trick is to look for ultra-light packaging. The same arguments apply to the very light but strong plastic bottles that are replacing heavier glass alternatives, thin-walled aluminum cans, and cartons made of composites that wrap up anything drinkable in an ultra-light package. There are hundreds of other tricks you can discuss with colleagues while gathering around the proverbial water cooler—filling up, naturally, your own mug rather than a disposable plastic cup. But you don't need to go as far as one website which tells you how to give your friends unwrapped Christmas presents. There are limits to source correctness.

阅读理解 Our understanding of cities in anything more than casual terms usually starts with observations of their spatial form and structure at some point or cross-section in time. This is the easiest way to begin, for it is hard to assemble data on how cities change through time, and, in any case, our perceptions often betray us into thinking of spatial structures as being resilient and long lasting. Even where physical change is very rapid, this only has an impact on us when we visit such places infrequently, after years away. Most of our urban theory, whether it emanates from the social sciences or engineering is structured around the notion that spatial and social structures change slowly and are sufficiently inert for us to infer resonable explanations from cross-sectional studies. In recent years, these assumptions have come to be challenged and in previous editorials I have argued the need for a more temporal emphasis to theories and models, where the emphasis is no longer on equilibrium but on the intrinsic dynamics of urban change. Even these views, however, imply a conventional wisdom where the real focus of urban studies is on processes that lead to comparatively slow changes in urban organization, where the functions determining such change are very largely routine, accomplished over months or years, rather than any lesser cycle of time. There is a tacit assumption that longer term change subsumes routine change on a day-to-day or hour-by-hour basis, which is seen as simply supporting the fixed spatial infrastructures that we perceive cities to be built around. Transportation modeling, for example, is fashioned from this standpoint in that routine trip-making behavior is the focus of study, its explanation being central to the notion that spatial structures are inert and long lasting.

阅读理解 Publishing in scientific journals is the most common and powerful means to disseminate new research findings. Visibility and credibility in the scientific world require publishing in journals that are included in global indexing databases such as those of the Institute for Scientific Information (ISI). Most scientists in developing countries remain at the periphery of this critical communication process, exacerbating the low international recognition and impact of their accomplishments. For science to become maximally influential and productive across the globe, this needs to change. The economy of electronic publication, open access, and property rights fuel current academic and policy debates about scientific publishing in the industrialized world. The concerns in the developing world (with few ISI-indexed journals) focus on more fundamental questions, such as sustaining local research activity and achieving the appropriate global reach of its science activities. The essence of the African situation is captured by R.J.W. Tijssen's analysis of publications by African authors, which was based not only on data from ISI indexing databases, but also on publications not indexed in this system. Surprisingly, half of the South African citations in the indexed ISI literature are to articles in nonindexed, locally published journals. Also, several nonindexed local journals are cited in the ISI system at about the same rate as are indexed journals. The share of indexed articles with at least one author with an African address remains steady at about 1%. About half of the ISI-indexed papers with at least one author with an African address have non-African partners outside of the continent. These figures vary, country by country, sometimes in surprising ways. For example, 85% of the papers published from Mali or Gabon involve collaborations on other continents, versus 39% and 29%, respectively, for South African and Egypt, the continent's leading research producers. Thus, much of the Africa research system is now highly dependent on collaborations. How can the global reach and potential impact of scientific research in Africa and other developing countries be optimized? Of primary importance is boosting the quality and quantity of work that is locally published, through measures including review of submissions by peers research opportunities. A proliferation of journals, short-lived publications, print-only journals, and poor distribution constitutes a picture that must change. A nationally organized project can probably make the biggest difference, with investment by government and research-support agencies, as well as wide participation by local and regional scientific communities.

阅读理解 Everyone has seen it happen. A colleague who has been excited involved, and productive slowly begins to pull back, lose energy and interest, and becomes a shadow of his or her former self. Or, a person who has been a beacon of vision and idealism retreats into despair or cynicism. What happened? How does someone who is capable and committed become a person who functions minimally and does not seem to care for the job or the people that work there? Burnout is a chronic state of depleted energy, lack of commitment and involvement, and continual frustration, often accompanied at work by physical symptoms, disability claims and performance problem. Job burnout is a crisis of spirit, when work that was once exciting and meaningful becomes deadening. An organization's most valuable resource—the energy, dedication, and creativity of its employees is often squandered by a climate that limits or frustrates the pool of talent and energy available. Milder forms of burnout are a problem at every level in every type of work. The burned-out manager comes to work, but he brings a shell rather than a person. He experiences little satisfaction, and feels uninvolved, detached, and uncommitted to his work and co-workers. While he may be effective by external standards, he works far below his own level of productivity. The people around him are deeply affected by his attitude and energy level, and the whole community begins to suffer. Burnout is a crisis of the spirit because people who burn out were once on fire. It's especially scary and consequential because it strikes some of the most talented. If they can't maintain their fire, others ask, who can? Are these people lost forever, or can the inner flame be rekindled? People often feel that burnout just comes upon them and that they are helpless victims of it. Actually, the evidence is growing that there were ways for individuals to safeguard and renew their spirit, and, more important, there are ways for organization to change conditions that lead to burnout.

阅读理解 You can have too much of a good thing, it seems—at least when it comes to physiotherapy after a stroke. Many doctors believe that it is the key to recovery: exercising a partially paralyzed limb can help the brain 'rewire' itself and replace neural connections destroyed by a clot in the brain. But the latest animal experiments suggest that too much exercise too soon after a brain injury can make the damage worse. 'It's something that clinicians are not aware of,' says Timothy Schallert of the University of Texas at Austin, who led the research. In some trials, stroke victims asked to put their good arm in a sling—to force them to use their partially paralyzed limb—had made much better recoveries than those who used their good arm. But these patients were treated many months after their strokes. Earlier intervention, Schallert reasoned, should lead to even more dramatic improvements. To test this theory, Schallert and his colleagues placed tiny casts on the good forelimbs of rats for two weeks immediately after they were given a small brain injury that partially paralyzed one forelimb. Several weeks later, the researchers were astonished to find that brain tissue surrounding the original injury had also died. 'The size of the injury doubled. It's a very dramatic effect.' says Schallert. Brain-injured rats that were not forced to overuse their partially paralyzed limbs showed no similar damage, and the casts did not cause a dramatic loss of brain tissue in animals that had not already suffered minor brain damage, In subsequent experiments, the researchers have found that the critical period for exercise-induced damage in rats is the first week after the initial brain injury. The spreading brain damage witnessed by Schallert's team was probably caused by the release of glutamate, a neurotransmitter, from brain cells stimulated during Limb movement. At high doses, glutamate is toxic even to healthy nerve cells. And Schallert believes that a brain injury makes neighboring cells unusually susceptible to the neurotransmitter's toxic effects. Randolph Nudo of the University of Texas Health Science Center at Houston, who studies brain injury in primates, agrees that glutamate is the most likely culprit. In experiments with squirrel monkeys suffering from stroke-like damage. Nudo tried beginning rehabilitation within five days of injury. Although the treatment was beneficial in the long run, Nudo noticed an initial worsening of the paralysis that might also have been due to brain damage brought on by exercise. Schallert stresses that mild exercise is likely to be beneficial however soon it begins. He adds that it is unclear whether human victims of strokes, like brain injured rats, could make their problems worse by exercising too vigorously, too soon. Some clinics do encourage patients to begin physiotherapy with a few weeks of suffering a traumatic head injury or stroke, says David Hovda, director of brain injury research at the University of California, Los Angeles. But even if humans do have a similar period of vulnerability to rats, he speculates that it might be possible to use drugs to block the effects of glutamate.

阅读理解 Today this dangerous situation has been largely alleviated. Henry, a 77-year-old pensioner from East London, still lives alone and happily practices golf swings in his back garden safe in the knowledge that his body is able to cope with the extra exertion. What has altered Henry's life is not some wonder drug but a simple change in the way his illness is managed. Every day Henry hooks himself up to monitoring devices whose results are helped him to understand it and overcome its more debilitating effects. 'Telehealth has given me confidence in myself because I know my own body now,' he says. He adjusts what he does according to what his daily readings tell him about his condition. Henry is just one of a growing number of pioneering patients who are trusting their futures to telehealth. Large trials are under way around the world to evaluate the idea. With elderly populations and the incidence of age-related illnesses growing telechealth promises to give people the independence they need to remain in their own homes. It could also reduce the burden of healthcare costs. The disorder that makes Henry's life so difficult is chronic obstructive pulmonary disease (DOPD), a condition that affects some 800,000 people in England. The airways in his lungs have narrowed, leaving him with severe shortness of breath and blood oxygen levels that can fall dangerously low. With his new equipment, Henry can keep a close eye on how his body is doing. He received for measuring his blood oxygen level and pulse rate, a blood pressure monitor and a set of speaking scales. Each connects wirelessly to a unit collates the readings and sends them to a team of medical specialists, who watch for suspicious changes. If the readings look bad, they call him to discuss appropriate action. Henry too can see the readings on his television, where they are displayed with the help of a special set-top box. Whether a day is good or bad depends largely on Henry's blood oxygen level. Before joining the telehealth program, he could only guess at that. Now he knows if the reading is low, he can take action. When the reading is high, he can go about his business confident that his oxygen level will see him through. 'Telehealth is a good thing for me,' says Henry. 'I know that on the other end of the telephone there's a little angel and if anything goes wrong it shows up on the television and she's on the phone within five minutes.'

阅读理解 Why do people always want to get up and dance when they hear music? The usual explanation is that there is something embedded in every culture—that dancing is a 'cultural universal'. A researcher in Manchester thinks the impulse may be even more deeply rooted than that. He says it may be a reflex reaction. Neil Todd, a psychologist at the University of Manchester, told that he first got an inkling that biology was the key after watching people dance to deafeningly loud music. 'There is a compulsion about it,' he says. He reckoned there might be a more direct, biological, explanation for the desire to dance, so he started to look at the inner ear. The human ear has two main functions: hearing and maintaining balance. The standard view is that these tasks are segregated so that organs for balance, for instance, do not have an acoustic function. But Todd says animal studies have shown that the sacculus, which is part of the balance-regulating vestibular system, has retained some sensitivity to sound. The sacculus is especially sensitive to extremely loud noise, above 70 decibels. 'There's no question that in a contemporary dance environment, the sacculus will be stimulated,' says Todd. The average rave, he says, blares music at a painful 110 to 140 decibels. But no one really knows what an acoustically stimulated sacculus does. Todd speculates that listening to extremely loud music is a form of 'vestibular self-stimulation': it gives a heightened sensation of motion. 'We don't know exactly why it causes pleasure,' he says. 'But we know that people go to extraordinary lengths to get it.' He lists bungee jumping, playing on swings or even rocking to and fro in a rocking chair as other examples of pursuits designed to stimulate the sacculus. The same pulsing that makes us feel as though we are moving may make us get up and dance as well, says Todd. Loud music sends signals to the inner ear which may prompt reflex movement. 'The typical pulse rate of dance music is around the rate of locomotion,' he says. 'It's quite possible you're triggering a spinal reflex.'

阅读理解 When it is sunny in June, my father gets in his first cutting of hay. He starts on the creek; meadows, which are flat, sandy, and hot. They are his driest land. This year, vacationing from my medical practice, I returned to Vermont to help him with the haying. The heft of a bale (大捆) through my leather gloves is familiar: the tautness of the twine, the heave of the bale, the sweat rivers that run through the hay chaff on my arms. This work has the smell of sweet grass and breeze. I walk behind the chug and clack of the baler, moving the bales into piles so my brother can do the real work of picking them up later. As hot as the air is, my face is hotter. I am surprised at how soon I get tired, I take a break and sit in the shade, watching my father bale, tying not to think about how old he is, how the heat affects his heart, what might happen. This is not my usual work, of course. My usual work is to sit with patients and listen to them. Occasionally I touch them, and am glad that my hands are soft. I don't think my patients would like farmer calluses and dirty hands on their tender spots. Reluctantly I feel for lumps in breasts and testicles, hidden swellings of organs and joints, and probe all the painful places in my patients' lives. There are many. Perhaps I am too soft, to stand calluses of a different sort. I feel heavy after a day's work, as if all my patients were inside me, letting me carry them. I don't mean to. But where do I put their stories? The childhood beatings, ulcers from stress, incapacitating depression, fears, illness? These are not my experiences, yet I feel them and carry them with me. I search out these stories in my patients, try to reorganize them, try to find healthier meanings. I spent the week before vacation crying. The hay field is getting organized. Piles of three and four bales are scattered around the field. They will be easy to pick up. Dad climbs, tired and lame, from the tractor. I hand him a jar of ice water, and he looks with satisfaction on his job just done. I'll stack a few more bales and maybe drive the truck for my brother. My father will have some appreciative customers this winter, as he sells his bales of hay. I've needed to feel this heaviness in my muscles, the heat on my face. I am taunted by the simplicity of this work, the purpose and results, the definite boundaries of the fields, the dimensions of the bales, for illness is not defined by the boundaries of bodies; it spills into families, homes, schools, and my office, like hay tumbling over the edge of the cutter bar. I feel the rough stubble left in its wake. I need to remember the stories I've helped reshape, new meanings stacked against the despair of pain. I need to remember the smell of hay in June.

阅读理解 The biggest thing in operating rooms these days is a million-dollar, multi-armed robot named da Vinci, used in nearly 400,000 surgeries nationwide last year—triple the number just four years earlier. But now the high-tech helper is under scrutiny over reports of problems, including several deaths that may be linked with it and the high cost of using the robotic system. There also have been a few disturbing, freak incidents: a robotic hand that wouldn't let go of tissue grasped during surgery and a robotic arm hitting a patient in the face as she lay on the operating table. Is it time to curb the robot enthusiasm? Some doctors say yes, concerned that the 'wow' factor and heavy marketing have boosted use. They argue that there is not enough robust research showing that robotic surgery is at least as good or better than conventional surgeries. Many U. S. hospitals promote robotic surgery in patient brochures, online and even on highway billboards. Their aim is partly to attract business that helps pay for the costly robot. The da Vinci is used for operations that include removing prostates, gallbladders and wombs, repairing heart valves, shrinking stomachs and transplanting organs. Its use has increased worldwide, but the system is most popular in the United States. For surgeons, who control the robot while sitting at a computer screen rather than standing over the patient, these operations can be less tiring. Plus robot hands don't shake. Advocates say patients sometimes have less bleeding and often are sent home sooner than with conventional laparoscopic surgeries and operations involving large incisions. But the Food and Drug Administration is looking into a spike in reported problems during robotic surgeries. Earlier this year, the FDA began a survey of surgeons using the robotic system. The agency conducts such surveys of devices routinely, but FDA spokeswoman Synim Rivers said the reason for it now 'is the increase in number of reports received' about da Vinci. Reports filed since early last year include at least five deaths. Whether there truly are more problems recently is uncertain. Rivers said she couldn't quantify the increase and that it may simply reflect more awareness among doctors and hospitals about the need to report problems. Doctors aren't required to report such things; device makers and hospitals are. Company spokesman Geoff Curtis said intuitive Surgical has physician-educators and other trainers who teach surgeons how to use the robot. But they don't train them how to do specific procedures robotically, he said, and that it's up to hospitals and surgeons to decide 'if and when a surgeon is ready to perform robotic cases.' A 2010 New England Journal of Medicine essay by a doctor and a health policy analyst said surgeons must do at least 150 procedures to become adept at using the robotic system. But there is no expert consensus on how much training is needed. New Jersey banker Alexis Grattan did a lot of online research before her gallbladder was removed last month at Hackensack University Medical Center. She said the surgeon's many years of experience with robotic operations was an important factor. She also had heard that the surgeon was among the first to do the robotic operation with just one small incision in the belly button, instead of four cuts in conventional keyhole surgery.

阅读理解 The first line reads: 'She sits on the bed with a helpless expression. What is your name? Auguste. Last name? Auguste. What is your husband's name? Auguste, I think.' The 32 pages of medical records that follow are the oldest medical description of Alzheimer's disease. Psychiatrist Konrad Maurer and his colleagues at Johann Wolfgan Goethe University in Frankfurt found the file in their hospital's archive, where it had been missing for nearly 90 years, and published excerpts from it last May in The Lancet. The notes, in a cramped, archaic German script, were written by Alois Alzheimer—the physician who first described the disease. His patient, Auguste D, was a 51-year-old woman who had suffered fits of paranoid jealousy and memory lapses so disturbing that her family finally brought her to a local hospital known as the Castle of the Insane. Over the next four years Alzheimer tracked her condition. Upon her death he examined her brain tissue and found the distinctive lesion that are now hallmark of the disease. Today Alzheimer's afflicts some 4 million Americans. Although it still cannot be cured, or even treated very well, several recent studies hint that some treatments—from estrogen to vitamin E to anti-inflammatory drugs—can reduce either the risk of developing the disorder or its symptoms. And more is being learned about its distinctive pathology. This past year, for instance, researchers discovered a new kind of lesion in Alzheimer's patients. A genetic study also pinpointed a mutation that is present in some 60 percent of them—a mutation in the DNA of mitochondria, the energy-producing organelles of the cells. But nearly a century ago, it was Alois Alzheimer who first described the disease and in so doing became one of the first physicians to offer a biological basis for a psychiatric condition. Finding the file, Maurer says, 'is like holding history in your hands.'

阅读理解 Optical illusions are like magic, thrilling us because of their capacity to reveal the fallibility of our senses. But there's more to them than that, according to Dr. Beau Lotto, who is wowing the scientific world with work that crosses the boundaries of art, neurology, natural history and philosophy. What they reveal, he says, is that the whole world is the creation of our brain. What we see, what we hear, feel and what we think we know is not a photographic reflection of the world, but an instantaneous unthinking calculation as to what is the most useful way of seeing the world. It's a best guess based on the past experience of the individual, a long evolutionary past that has shaped the structure of our brains. The world is literally shaped by our pasts. Dr. Lotto, 40, an American who is a reader in neuroscience at University College London, has set out to prove it in stunning visual illusions, sculptures and installations, which have been included in art-science exhibitions. He explains his complex ideas from the starting point of visual illusions, which far from revealing how fragile our senses are show how remarkably robust they are at providing a picture of the world that serves a purpose to us. For centuries, artists and scientists have noted that a grey dot looks lighter against a dark background than being against a light background. The conventional belief was that it was because of some way the brain and eye is intrinsically wired. But Dr. Lotto believes it's a learnt response; in other words, we see the world not as it is but as it is useful to us. 'Context is everything, because our brains have evolved to constantly re-define normality,' says Dr. Lotto. 'What we see is defined by our own experiences of the past, but also by what the human race has experienced through its history.' This is illustrated by the fact that different cultures and communities have different viewpoints of the world, conditioned over generations. For example, Japanese people have a famous inability to distinguish between the 'R' and the 'L' sound. This arises because in Japanese the sounds are totally interchangeable. 'Differentiating between them has never been useful, so the brain has never learnt to do it. It's not just that Japanese people find it hard to tell the difference. They literally cannot hear the difference.' Dr. Lotto's experiments are grounding more and more hypotheses in hard science. 'Yes, my work is idea-driven,' he says. 'But lots of research, such as MRI brain scanning, is technique-driven. I don't believe you can understand the brain by taking it out of its natural environment and looking at it in a laboratory. You have to look at what it evolved to do, and look at it in relationship to its ecology.'

阅读理解Famed singer Stevie Wonder can’t see his fans dancing at his concerts. He can’t see the hands of hisaudience as they applaud wildly at the end of his superstition.Blind from birth, Wonder has waited his whole life for a chance to see. Recently, Wonder visitedMark Humayan, a vision specialist. He thought that a new device currently being studied byHumayan might offer him that chance.The device, a retinal prosthesis, is a tiny computer chip implanted inside a patient’s eye. The chipsends images to the brain and allows some sightless people to see shapes and colors. Wonder hopedthe retinal prosthesis might work for him. “I’ve always said that if ever there’s possibility of myseeing,” said Wonder, “then I would take the challenge.”Unfortunately for Wonder, that challenge will have to wait. Humayan explained that the device isn’tready for people who have been blind since birth. Their brains may not be able to handle signalsfrom a retinal prosthesis because their brains have never handled signals from a healthy eye.The retinal prosthesis and other devices, however, show great promise in helping many othersightless people who once had vision see again. Perhaps one day soon, some formerly sightlesspeople may be in Wonder’s audience looking up—and seeing him—for the very first time.Wonder’s willingness to take part in retinal prosthesis studies and the results of those studies aregiving new hope to people who thought they would be blind for the rest of their lives. More than onemillion people in the United States are considered legally blind, meaning that their eyesight isseverely impaired. Another one million are totally blind.Two types of specialized cells in the retina—rods and cones—are critical for proper vision. Lightenters the eye and falls on the rods and cones in the retina. Those cells convert the light to electricalsignals which travel through the optic nerve to the brain. The brain interprets those signals as visualimages. Rods detect light at low levels of illumination. For instance, rods allow you to see faintshadows in dim moonlight. Cones, on the other hand, are most sensitive to color. Some diseases candamage cells in the retina. For instance, macular degeneration causes blindness and other visionproblems in 700,000 people in the United States each year. The condition is caused by a lack ofadequate blood supply to the central part of the retina. Without blood, the rods, cones, and other cellsin the retina die.Devices such as the retinal prostheses won’t prevent or cure our eye diseases, but they may helppatients who have eye disorders regain some of their vision. Different forms of retinal prostheses arecurrently being developed. On one type, a tiny computer chip is embedded in the eye. The chip has agrid of about 2,500 light-sensing elements called pixels.Light entering the eye strikes the pixels, which convert the light into electrical signals. The pixelsthen send the electrical signals to nerve cells behind the retina. Those cells send signals via the opticnerve to the brain for interpretation.Many people who have had a retinal prosthesis implanted say they can see shapes, colors, andmovements that they couldn’t see before. “It was great,” said Harold Churchey, who received hisretinal prosthesis 15 years after he became totally blind. “To see light after so long—it was justwonderful. It was just like switching a light on.”

阅读理解 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 Shimokata. '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.

阅读理解 The alarm on our household computer terminal rings and wakes me up. My husband simply stirs and goes back to sleep. I transfer today's information onto the personal data card I carry with me everywhere and scan today's readings. Values are given as to the number of liters of water I can use, the amount of coal-generated electricity I have allocated and how many 'enviro-credits' I have learned. I am free to use the water and electricity as I chose, however I notice that the ration of electricity is decreasing every day. Of course, this will not be a problem when we have earned enough enviro-credits to buy another solar panel. Enviro-credits are earned by buying goods with limited of no packaging, minimizing the amount of garbage thrown out by financially supporting 'environtechnology'. Before cars were phased out due to unpopularity, credits could be gained by using public transport. I notice all extra passage added to the readings. At last I have been given permission to have a child. Almost instantaneously a package arrives with a label on it-'Anti-sterilization Unit'. Inside there are instructions and a small device that looks like a cross between a pistol and a syringe. Eagerly I follow the instructions. The procedure is painless and I don't know if I am imagining it but I seem to feel the effects at once. Shaking my husband awake, I tell him the good news. I want to get started baby-making right now. 'You've been on the waiting list for 37 years,' he says, 'Can't you wait until I've woken up properly?' I decide that I probably don't have much choice and wander downstairs. I am feeling very privileged to have the opportunity to create a new life. It is saddening, however, when I realize that, because of strict population controls, this new life will be replacing an old one. I decide to ring my mother and tell her the good news. When she answers the phone she is crying. She has received word that my grandmother has failed her latest health check and will be euthanized next week. For some reason, I don't feel like creating that new life anymore.

阅读理解 Parents are on a journey of discovery with each child whose temperament, biology, and sleep habits result in a unique sleep-wake pattern. It can be frustrating when children's sleep habits do not conform to the household schedule. Helping the child develop good sleep habits in childhood takes time and parental attention, but it will have beneficial results throughout life. An understanding of the changing patterns of the typical sleep-wake cycle in children will help alleviate any unfounded concerns. Maintaining a sleep diary for each child will provide the parents with baseline information in assessing the nature and severity of childhood sleep problems. Observant patents will come to recognize unusual sleep disruptions or those that persist or intensify. Developmental changes throughout childhood bring differences in the sleep-wake cycle and in the type and frequency of parasomnias that may interrupt sleep. Medical consultation to rule out illness, infection of injury is prudent if the child's sleep problems prevent adequate sleep and result in an ongoing sleep deficit. As reported by News-Medical in Child Health News, children's sleep problems should be taken seriously as they may be a 'marker' for predicting later risk of early adolescent substance use.' In the same article. University of Michigan psychiatry professor Kirk Brower, who has studied 'the interplay of alcohol and sleep in adults' stressed that 'The finding does not mean there's a cause-and-effect relationship.' Consultation with a child psychologist may be helpful if frightening dreams intensify and become more frequent as this may indicate a particular problem or life circumstance that needs to be changed or one that the child may need extra help working through. Most childhood sleep disturbance will diminish over time as the brain matures and a regular sleep-wake cycle is established. Parental guidance is crucial to development of healthy sleep habits in children.