单选题It's bad biology to argue against the existence of animal emotions. Scientific research in evolutionary biology, cognitive ethology and social neuroscience support the view that numerous and diverse animals have rich and deep emotional lives. Emotions have evolved as adaptations in numerous species and they serve as a social glue to bond animals with one another. Emotions also catalyze and regulate a wide variety of social encounters among friends and competitors and permit animals to protect themselves adaptively and flexibly using various behavior patterns in a wide variety of venues. Charles Darwin's well-accepted ideas about evolutionary continuity, that differences among species are differences in degree rather than kind, argue strongly for the presence of animal emotions, empathy, and even moral behavior. In practice, continuity allows us to connect the "evolutionary dots" among different species to highlight similarities in evolved traits including individual feelings and passions. What we have since learned about animal emotions and empathy fits in well with what we know about the lifestyle of different species—how complex their social interactions and social networks are. Emotions, empathy, and knowing right from wrong are keys to survival, without which animals—both human and nonhuman—would perish. That's how important they are. The borders between "them" (animals) and "us" are murky and permeable. Studying animal emotions addresses a number of big questions concerning how science is conducted. Many skeptics feel that we are so uncertain about whether other animals have any sort of emotional life that they prefer to put off weighing in until we know more. For some, this really means waiting until we are absolutely sure. But science is never as certain as many would like it to be. Climate change researcher Henry Pollack says it well in his book Uncertain Science... Uncertain World: "Because uncertainty never disappears, decisions about the future, big and small, must always be made in the absence of certainty. Waiting until uncertainty is eliminated is an implicit endorsement of the status quo, and often an excuse for maintaining it... Uncertainty, far from being a barrier to progress, is actually a strong stimulus for, and an important ingredient of, creativity." I often begin my lectures with the question: "Is there anyone in this audience who thinks that dogs don't have feelings—that they don't experience joy and sadness?" I've never had an enthusiastic response to this question, even in scientific gatherings, although on occasion a hand or two goes up slowly, usually halfway, as the person glances around to see if anyone is watching. But if I ask, "How many of you believe that dogs have feelings?" Then almost every hand waves wildly and people smile and nod in vigorous agreement. Using behavior as our guide, by analogy we map the feelings of other beings onto our own emotional templates, and we do it very reliably.

单选题What is the nature of the scientific attitude, the attitude of the man or woman who studies and applies physics, biology, chemistry, geology, engineering, medicine or any other science? We all know that science plays an important role in the societies in which we live. Many people believe, however, that progress depends on two different aspects of science. The first of these is the application of the machines, products and systems of applied knowledge that scientists and technologists develop. Through technology, science improves the structure of society and helps man to gain increasing control over his environment. The second aspect is the application by all members of society of the special methods of thought and action that scientists use in their work. What are these special methods of thinking and acting? First of all, it seems that a successful scientist is full of curiosity—he wants to find out how and why the universe works. He usually directs his attention towards problems which he notices have no satisfactory explanation, and his curiosity makes him look for underlying relationships even if the data available seems to be unconnected. Moreover, he thinks he can improve the existing conditions and enjoys trying to solve the problems which this involves. He is a good observer, accurate, patient and objective and applies logical thought to the observations he makes. He utilizes the facts he observes to the fullest extent. For example, trained observers obtain a very large amount of information about a star mainly from the accurate analysis of the simple lines that appear in a spectrum. He is skeptical—he does not accept statements which are not based on the most complete evidence available—and therefore rejects authority as the sole basis for truth. Scientists always check statements and make experiments carefully and objectively to verify them.Furthermore, he is not only critical of the work of others, but also of his own, since he knows that man is the least reliable of scientific instruments and that a number of factors tend to disturb objective investigation. Lastly, he is highly imaginative since he often has to look for relationships in data which are not only complex but also frequently incomplete. Furthermore, he needs imagination if he wants to make hypotheses of how processes work and how events take place. These seem to be some of the ways in which a successful scientist or technologist thinks and acts.

单选题British scientists are preparing to launch trials of a radical new way to fight cancer, which kills tumours by infecting them with viruses like the common cold. If successful, virus therapy could eventually form a third pillar alongside radiotherapy and chemotherapy in the standard arsenal against cancer, while avoiding some of the debilitating side-effects. Leonard Seymour, a professor of gene therapy at Oxford University, who has been working on the virus therapy with colleagues in London and the U.S., will lead the trials later this year. Cancer Research UK said yesterday that it was excited by the potential of Prof. Seymour's pioneering techniques. One of the country's leading geneticists, Prof. Seymour has been working with viruses that kill cancer cells directly, while avoiding harm to healthy tissue. " In principle, you've got something which could be many times more effective than regular chemotherapy," he said. Cancer-killing viruses exploit the fact that cancer cells suppress the body's local immune system. " If a cancer doesn't do that, the immune system wipes it out. If you can get a virus into a tumour, viruses find them a very good place to be because there's no immune system to stop them replicating. You can regard it as the cancer's Achilles' heel." Only a small amount of the virus needs to get to the cancer. "They replicate, you get a million copies in each cell and the cell bursts and they infect the tumour cells adjacent and repeat the process," said Prof. Seymour. Preliminary research on mice shows that the viruses work well on tumours resistant to standard cancer drugs. "It's an interesting possibility that they may have an advantage in killing drug-resistant tumours, which could be quite different to anything we've had before." Researchers have known for some time that viruses can kill tumour cells and some aspects of the work have already been published in scientific journals. American scientists have previously injected viruses directly into tumours but this technique will not work if the cancer is inaccessible or has spread throughout the body. Prof. Seymour's innovative solution is to mask the virus from the body' s immune system, effectively allowing the viruses to do what chemotherapy drugs do—spread through the blood and reach tumours wherever they are. The big hurdle has always been to find a way to deliver viruses to tumours via the bloodstream without the body' s immune system destroying them on the way."What we' ve done is make chemical modifications to the virus to put a polymer coat around it—it' s a stealth virus when you inject it," he said. After the stealth virus infects the tumour, it replicates, but the copies do not have the chemical modifications. If they escape from the tumour, the copies will be quickly recognised and mopped up by the body' s immune system. The therapy would be especially useful for secondary cancers, called metastases, which sometimes spread around the body after the first tumour appears. "There's an awful statistic of patients in the west... with malignant cancers; 75% of them go on to die from metastases," said Prof. Seymour. Two viruses are likely to be examined in the first clinical trials: adenovirus, which normally causes a cold-like illness, and vaccinia, which causes cowpox and is also used in the vaccine against smallpox. For safety reasons, both will be disabled to make them less pathogenic in the trial, but Prof. Seymour said he eventually hopes to use natural viruses. The first trials will use uncoated adenovirus and vaccinia and will be delivered locally to liver tumours, in order to establish whether the treatment is safe in humans and what dose of virus will be needed. Several more years of trials will be needed, eventually also on the polymer-coated viruses, before the therapy can be considered for use in the NHS. Though the approach will be examined at first for cancers that do not respond to conventional treatments, Prof. Seymour hopes that one day it might be applied to all cancers.

单选题In the 1962 movie Lawrence of Arabia, one scene shows an American newspaper reporter eagerly snapping photos of men looting a sabotaged train. One of the looters, Chief Auda abu Tayi of the Howeitat clan, suddenly notices the camera and snatches it. "Am I in this?" he asks, before smashing it open. To the dismayed reporter, Lawrence explains, "He thinks these things will steal his virtue. He thinks you're a kind of thief. " As soon as colonizers and explorers began taking cameras into distant lands, stories began circulating about how indigenous peoples saw them as tools for black magic. The "ignorant natives" may have had a point. When photography first became available, scientists welcomed it as a more objective way of recording faraway societies than early travelers' exaggerated accounts. But in some ways, anthropological photographs reveal more about the culture that holds the camera than the one that stares back. Up into the 1950s and 1960s, many ethnographers sought "pure" pictures of "primitive" cultures, routinely deleting modern accoutrements such as clocks and Western dress. They paid men and women to re-enact rituals or to pose as members of war or hunting parties, often with little regard for veracity. Edward Curtis, the legendary photographer of North American Indians, for example, got one Makah man to pose as a whaler with a spear in 1915—even though the Makah had not hunted whales in a generation. These photographs reinforced widely accepted stereotypes that indigenous cultures were isolated, primitive, and unchanging. For instance, National Geographic magazine's photographs have taught millions of Americans about other cultures. As Catherine Lutz and Jane Collins point out in their 1993 book Reading National Geographic, the magazine since its founding in 1888 has kept a tradition of presenting beautiful photos that don't challenge white, middle-class American conventions. While dark-skinned women can be shown without tops, for example, white women's breasts are taboo. Photos that could unsettle or disturb, such as areas of the world torn asunder by war or famine, are discarded in favor of those that reassure to conform with the society's stated pledge to present only "kindly" visions of foreign societies. The result, Lutz and Collins say, is the depiction of "an idealized and exotic world relatively free of pain or class conflict. " Lutz actually likes National Geographic a lot She read the magazine as a child, and its lush imagery influenced her eventual choice off anthropology as a career. She just thinks that as people look at the photographs of other cultures, they should be alert to the choice of composition and images.

单选题At 9:00 in the evening on January 29, just as President George W. Bush was about to begin his first State of the Union address, I gathered with three anxious scientists in a small, windowless laboratory in Worcester, Massachusetts. We were at Advanced Cell Technology—a privately owned biotechnology company that briefly made international headlines last fall by publishing the first scientific account of cloned human embryos. The significance of the achievement was debatable: the company's most successful embryo had reached only six cells before it stopped dividing (one other had reached four cells, another had reached two) — a fact that led to a widespread dismissal, in the media and the scientific community, of ACT's "breakthrough". The work was largely judged to be preliminary, inconsequential, and certainly not worthy of headlines. Many people in political and religious circles, however, had a decidedly different view. They deemed ACT's work an ethical transgression of the highest order and professed shock, indignation, and horror. Nonetheless, ACT was pressing ahead—which was why I had come to the company's cloning lab that night in January. The door to the lab was locked; a surveillance camera mounted on the ceiling watched our every move; and the mood was at once urgent and tense. A human egg, retrieved just hours earlier from a young donor, was positioned under a microscope, its image glowing on a nearby video monitor. The egg's chromosomes would shortly be removed, and the scientists in the room would attempt to fuse what remained of the egg with a human skin cell. If the procedure succeeded, the result would be a cloned human embryo. Skin cell to embryo—it's one of the most remarkable quick-change scenarios modern biology has to offer. It's also one of the most controversial. Since the announcement, in 1997, of the cloning of the sheep Dolly, attempts to use human cells for cloning have provoked heated debate in the United States, separating those who have faith in the promise of the new technology from those who envision its dark side and unintended consequences. Crucial to the debate is the fact that human cloning research falls into two distinct categories: reproductive cloning, a widely frowned-on effort that aims to produce a fully formed child; and therapeutic cloning, a scientifically reputable procedure that takes place entirely at the microscopic level and is designed to advance medical therapies and cure human ailments. The two start out the same way— with a new embryo in a Petri dish. But the scientists I was observing in the lab had no intention of creating a person. Instead they were embarking on an experiment that, if successful, would be a first step toward creating radical new cures for patients like the donor of the skin cell—Trevor Ross (not his real name), a two-year-old boy afflicted with a rare and devastating genetic disease. The mood in the lab was tense in part because of the uncertain outcome of the experiment. But it was also tense because of concern over what President Bush might say about cloning in his address to the nation. A radio in one corner of the room was tuned to the broadcast as the scientists began their work, and they were listening carefully: in perhaps no other fields of science are researchers as mindful of which way the political winds are blowing. The ACT scientists had good reason to be concerned—what they were doing that night might soon be made illegal.

单选题Behaviors that we do not understand often become nearly invisible—even when, in retrospect, we see how truly strange they are. When I was a psychiatric resident, we had a faculty member who was famous for his messy office: stacks of papers and old journals covered every chair and table as well as much of the floor. One day, as I walked past the open office door with one of my supervisors, he murmured mildly, "odd duck". And that was as far as anyone seemed to reflect on this peculiar state of affairs within an institution staffed by psychiatrists. Eventually, the faculty member had to be given another office in which to see patients. Not surprisingly, the psychiatric diagnostic manual does not list "messy room" in the index. But it does mention a symptom: inability "to discard worn-out or worthless objects even when they have no sentimental value". It comes under the diagnosis obsessive-compulsive personality disorder, an obscure cousin of the more famous obsessive-compulsive disorder. I was barely aware of the diagnosis. Every era has popular mental disorders due to cultural or scientific reasons. In Freud's day it was hysteria. Currently, depression has moved to center stage. But other ailments go relatively ignored, and this disorder was one. It came with a list of additional symptoms that appeared to be peculiar bedfellow: anxiety about spending money, excessive devotion to work to the exclusion of leisure activities, rigidity about following rules, and perfectionism in doing takes — at times to the point of interfering with finishing them. In moderation, the symptoms seemed to fit right in with our workaholic culture — perhaps explaining the low profile of the diagnosis. Relentless work orientation and perfectionism may even be assets in rule and detail oriented professions like accounting or law. But when the symptoms are too intense or pervasive, they become crippling. Beneath seemingly adaptive behaviors lies a central disability. People with this diagnosis have enormous difficulty making decisions. They lack the internal sense of completion that most of us experience at the end of a choice or a task, even one as simple as throwing something out or making a purchase. In obsessive-compulsive personality disorder, this feeling occurs only after endless deliberation and revision, if at all. The need to come up with the "correct" answer, the best purchase or the perfect proposal leads to excess rumination over each decision. It can even lead to complete paralysis. For such people, rules of all kinds are a godsend — they represent pre-made decisions. Open-ended assignments, like writing papers, are nightmares. For such a patient or for a psychiatrist, understanding a cluster of diagnostic symptoms can be a revelation. The picture leaps out from the previously disorganized background. But undoubtedly, at times we can become too reductionistic, seeing patterns where none exist: sometimes a messy room is just a messy room.

单选题There is a great irony of 21st-century global health: While many hundreds of millions of people lack adequate food as a result of economic inequities, political corruption, or warfare, many hundreds of millions more are overweight to the point of increased risk for diet-related chronic diseases. Obesity is a worldwide phenomenon, affecting children as well as adults and forcing all but the poorest countries to divert scarce resources away from food security to take care of people with preventable heart disease and diabetes. To reverse the obesity epidemic, we must address the fundamental causes. Overweight comes from consuming more food energy than is expended in activity. The cause of this imbalance also is ironic: improved prosperity. People use extra income to eat more and be less physically active. Market economies encourage this. They make people with expendable income into consumers of aggressively marketed foods that are high in energy but low in nutritional value, and of cars, televisions set. And computers that promote sedentary behavior. Gaining weight are good business. Food is particularly big business because everyone eats. Moreover, food is so overproduced that many countries, especially the rich ones that far more than they need, another irony, than the United States, to take an extreme example, most adults—-of all ages, incomes, educational levels, and census categories—are overweight. The U. S. food supply provides 3800 kilocalories per person per day, nearly twice as much as required by many a-dults. Overabundant food forces companies to compete for sales through advertising, health claims, new products, larger portions, and campaigns directed toward children. Food marketing promotes weight gain. Indeed, it is difficult to think of any major industry that might benefit if people ate! Less food; certainly not the agriculture, food product, grocery, restaurant, diet or drug industries. All flourish when people eat more. And all employ armies of Lobbyists to discourage governments from doing anything to inhibit overeating.

单选题"Back in the Victorian era, seven out of ten ulcer sufferers were woman. By the 1950s, the trend had reversed, nine of ten were men. Now, the trend is shifting back, ulcer cases are only four times as frequent among men. This may be a consequence of the changing roles of women in the labor market," writes Philip Goldberg in Executive Health. Ulcers have long been linked to stress and the particular kind of frustration that stems from dissatisfaction with one' s work performance or one' s life. Digestive enzymes gnaw away at the stomach lining, causing painful sores, or ulcers, which are found mainly in the lining of the stomach or the small intestine. The acids which cause ulcers are triggered by the vagus nerve, which is linked to the brain. Under stress, the brain may stimulate the release of a hormone called gastrin, which, in turn, stimulates the acid secretions. " Although there is no clear-cut ulcer personality, there is no doubt that emotional tension, acting through the vagus nerve, can precipitate an ulcer. A person who is under constant strain, who is anxious, worried, frustrated—regardless of his or her station in life or apparent demeanor—is more apt to develop an ulcer," writes Jane Broky in her guide to personal health, adding, "Seemingly calm, relaxed people are as prone to ulcers as the hard-driving, high-pressure kind. Ulcers occur as often in bus drivers, fanners, and construction workers as in business executives and writers with deadlines. It is not the existence of stress, but how a person reacts to stress, that, seems to make the difference. " Some women appear to "inherit" ulcers but they also can be caused by aspirin, alcohol, coffee , and cigarette smoking(which may account for the increase of ulcers among women, since smoking among women is on the rise.)It is important to see a physician if an ulcer is suspected, since ulcers can eat through the stomach lining into other organs and occasionally be fatal. Doctors will usually recommend a number of treatments, including emotional counseling and diet changes. Stress-reducing techniques also have been successful in treating ulcers.

单选题The biosphere is the name biologists give to the sort of skin on the surface of this planet that is inhabitable by living organisms. Most land creatures occupy only the interface between the atmosphere and the land; birds extend their range for a few hundred feet into the atmosphere; burrowing invertebrates such as earthworms may reach a few yards into the soil but rarely penetrate father unless it has been recently disturbed by men. Fish cover a wider range, from just beneath the surface of the sea to those depths of greater than a mile inhabited by specialized creatures. Fungi and bacteria are plentiful in the atmosphere to a height of about half a mile, blown there hy winds from the lower air. Balloon exploration of the stratosphere as long ago as 1936 indicated that moulds and bacteria could be found at heights of several miles, recently the USA's National Aeronautics and Space Administration has detected them, in decreasing numbers, at heights up to eighteen feet, compared with 50 tO 100 per cubic foot at two to six miles (the usual altitude of jet aircraft), and they are almost certainly in an inactive state. Marine bacteria have been detected at the bottom of the deep Pacific trench, sometimes as deep as seven miles; they are certainly not inactive. Living microbes have also been obtained on land from cores of rock drilled (while prospecting for oil) at depths of as much as 1, 200 feet. Thus we can say, disregarding the exploits of astronauts, that the biosphere has a maximum thickness of about twenty-five miles. Active living processes occur only within a compass of about seven miles, in the sea, on land and in the lower atmosphere, but the majority of living creatures live within a zone of a hundred feet or so. If this planet were scaled down to the size of an orange, the biosphere, at its extreme width, would occupy the thickness of the orange-colored skin, excluding the pith. In this tiny zone of our planet takes place the multitude of chemical and biological activities that we call life. The way in which living creatures interact with each other, depend on each other or compete with each other, has fascinated thinkers since the beginning of recorded history. Living things exist in a fine balance which is often taken for granted for, from a practical point of view, things could not be otherwise. Yet it is a source of continual amazement to scientists because of its intricacy and delicacy. The balance of nature is obvious most often when it is disturbed, yet even here it can seem remarkable how quickly it readjusts itself to a new balance after a disturbance. The science of ecology—the study of the interaction of organisms with their environment—has grown up to deal with the minutiae of the balance of nature.

单选题The American Society of Clinical Oncology wrapped its annual conference this week, going through the usual motions of presenting a lot of drugs that offer some added quality or extension of life to those suffering from a variety of as-yet incurable diseases. But buried deep in an AP story are a couple of promising headlines that seems worthy of more thorough review, including one treatment study where 100 percent of patients saw their cancer diminish by half. First of all, it seems pharmaceutical companies are moving away from the more cost-effective one-size-fits-all approach to drug development and embracing the long tail of cancer treatments, engineering drugs that only work for a small percentage of patients but work very effectively within that group. Pfizer announced that one such drug it's pushing into late-stage testing is target for 4% of lung cancer patients. But more than 90% of that tiny cohort responded to the drug in initial tests, and nine out often is getting pretty close to the ideal ten out of ten. By gearing drugs toward more boutique treatments rather than broad umbrella pharmaceuticals that try to fit for everyone it seems cancer researchers are making some headway. But how can we close the gap on that remaining ten percent? Ask Takeda Pharmaceutical and Celgene, two drug makers who put aside competitive interests to test a novel combination of their treatments. In a test of 66 patients with the blood disease multiple myeloma, a full 100 percent of the subjects saw their cancer reduced by half. Needless to say, a 100 percent response to a cancer drug (or in this case a drug cocktail) is more or less unheard of. Moreover, this combination never would've been tried if two competing companies hadn't sat down and put their heads together. Are there more potentially effective drug combos out there separated by walls of competitive interest and proprietary information? Who's to say, but it seems like with the vast amount of money and research being pumped into cancer drug development, the odds are pretty good. And if researchers can start pushing more of their response numbers toward 100 percent, we can more easily start talking about oncology's favorite four-letter word: cure.

单选题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 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, trying 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 callouses 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, could stand callouses of a different sort. I feel heavy after a day" s work, as if 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. 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" 11 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.

单选题Fried foods have long been frowned upon. Nevertheless, the skillet is about our handiest and most useful piece of kitchen equipment. Stalwart lumberjacks and others engaged in active labor requiring 4, 000 calories per day or more will take approximately one-third of their rations prepared in this fashion. Meat, eggs, and French toast cooked in this way are served in millions of homes daily. Apparently the consumers are not beset with more signs of indigestion than afflict those who insist upon broiling, roasting, or boiling. Some years ago one of our most eminent physiologists investigated the digestibility of fried potatoes. He found that the pan.variety was more easily broken down for assimilation than when deep fat was employed. The latter, however, dissolved within the alimentary tract more readily than the boiled type. Furthermore, he learned, by watching the progress of the contents of the stomach by means of the fluoroscope, that fat actually accelerated the rate of digestion. Now all this is quite in contrast with "authority". Volumes have been written on nutrition, and everywhere the dictum has been accepted—no fried edibles of any sort for children. A few will go so far as to forbid this style of cooking wholly. Now and then an expert will be bold e-nough to admit that he uses them himself, the absence of discomfort being explained on the ground that he possesses a powerful gastric apparatus. We can of course sizzle perfectly good articles to death so that they will be leathery and tough. But thorough heating, in the presence of shortening, is not the awful crime that it has been labeled. Such dishes stimulate rather than retard contractions of the gall bladder. Thus it is that bile mixes with the nutriment shortly after it leaves the stomach. We don" t need to allow our foodstuffs to become oil-soaked, but other than that, there seems to be no basis for the widely heralded prohibition against this method. But notions become fixed. The first condemnation probably arose because an "oracle" suffered from dyspepsia, which he ascribed to some fried item on the menu. The theory spread. Others agreed with him, and after a time the doctrine became incorporated in our textbooks. The belief is now tradition rather than a proved fact. It should have been refuted long since, as experience has demonstrated its falsity.

单选题We all have offensive breath at one time or another. In most cases, offensive breath emanates from bacteria in the mouth, although there are other, more surprising causes. Until a few years ago, the most doctors could do was to counsel patients with bad breath about oral cleanliness. Now they are finding new ways to treat the usually curable condition. Bad breath can happen whenever the normal flow of saliva slows. Our mouths are full of bacteria feeding on protein in bits of food and shed tissue. The bacteria emit evil-smelling gases, the worst of which is hydrogen sulfide. Mouth bacteria thrive in airless conditions. Oxygen-rich saliva keeps their numbers down. When we sleep, for example, the saliva stream slows, and sulfur-producing bacteria gain the upper hand, producing classic "morning breath". Alcohol, hunger, too much talking, breathing through the mouth during exercise—anything that dries the mouth produces bad breath. So can stress, though it's not understood why. Some people's breath turns sour every time they go on a job interview. Saliva flow gradually slows with age, which explains why the elderly have more bad-breath trouble than younger people do. Babies, however, who make plenty of saliva and whose mouths contain relatively few bacteria have characteristically sweet breath. For most of us, the simple, dry-mouth variety of bad breath is easily cured. Eating or drinking starts saliva and sweeps away many of the bacteria. Breakfast often stops morning breath. Those with chronic dry mouth find that it helps to keep gum, hard candy, or a bottle of water or juice around Brushing the teeth wipes out dry-mouth bad breath because it clears away many of the offending bacteria. Surprisingly, one thing that rarely works is mouthwash. The liquid can mask bad-breath odor with its own smell, but the effect lasts no more than an hour. Some mouthwashes claim to kill the bacteria responsible for bad breath. The trouble is, they don't necessarily reach all offending germs. Most bacteria are well protected from mouthwash under thick layers of mucus. If the mouthwash contains alcohol—as most do—it can intensify the problem by drying out the mouth.

单选题For many environmentalists, all human influence on the planet is bad. Many natural scientists implicitly share this outlook. This is not unscientific, but it can create the impression that greens and environmental scientists are authoritarian tree-huggers who value nature above people. That doesn't play well with mainstream society, as the apparent backlash against climate scientist revels. Environmentalists need to find a new story to tell. Like it nor not, we now live in the antropocent (人类世) —an age in which humans are perturbing many of the planet's natural systems, from the water to the acidity of the oceans. We cannot wish that away we must recognize it and manage our impacts. Johan Rockstrom, head of the Stockholm Environment Institute in Sweden, and colleagues have distilled recent research on how Earth systems work into a list of nine "planetary boundaries" that we must stay within to live sustainably. It is preliminary work, and many will disagree with where the boundaries are set. But the point is to offer a new way of thinking about our relationship with the environment—a science-based picture that accepts a certain level of human impact and even allow us some room to expand. The result is a breath of fresh air: though we are already well past three of the boundaries, we haven't trashed the place yet. It is in the same spirit that we also probe the basis for key claims in the Intergovernmental Panel on Climate Change's 2007 report on climate impacts. This report has been much discussed since our revelations about its unsubstantiated statement on melting Himalayan glaciers. Why return to the topic? Because there is a sense that the IPCC shares the same anti-human agenda and, as a result, is too dangerous of unverified numbers. While the majority of the report is assuredly rigorous, there is no escaping the fact that parts of it make claims that go beyond the science. Above all, we need a dispassionate view of the state of the planet and our likely future impact on it. There is no room for complacency: Rockstrom's analysis shows us that we face real dangers, but exaggerating our problems is not the way to solve them.

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 mat 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 performed more than 800 of these operations and hopes to do an additional 1, 000 before he retires. Having performed the operation myself as a resident in neurosurgery, I was eager to see how the country's most prolific SDR surgeon does it. Last month I got an opportunity to stand by his side as he operated on 3-year-old Lane Hickman. 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Cancer is considered a modern disease, though it was not unknown in ancient times.(The condition was named by the Greeks from their word for crab, presumably because of its clawing, crablike growth). The incidence of cancer has risen dramatically in recent decades, primarily【C1】______cigarette smoking, and cancer is probably our most dreaded disease today. As a cause of death in the United States, cancer has climbed from less than 6 percent of all deaths in 1900 to over 20 percent today,【C2】______recent statistics. It is already the leading killer of women aged thirty to fifty-four. And add a killer of the overall population, it is second only to heart disease,【C3】______close to 430,000 deaths per year. This figure has risen annually since 1949, and if percent trends continue, cancer may well overtake heart disease as the number one cause of death. Can We Fight Cancer More Effectively Today? Although there is still much to be learned about cancer, our knowledge of the disease has grown steadily in recent years. We have a better understanding of the disease and are finding ways to【C4】______it. Early recognition of the signs of cancer, prompt diagnosis, and aggressive treatment by the appropriate means have made the word cancer less【C5】______than it used to be. Even people with forms of cancer that are still difficult to treat know that current techniques may【C6】______them to outwit the disease until improved treatment becomes available. Many cancer victims have hope where there was once despair. Even more important is the fact that some kinds of cancer are【C7】______caused by preventable factors—for example, 25 to 30 percent of all cancer deaths are related to cigarette smoking, and most skin cancer is caused by【C8】______exposure to the sun. Not all forms of cancer have such obvious associations, but where risk factors have been【C9】______. we can use this knowledge and attempt to reduce the odds of developing those particular forms of disease. You and the people you know can【C10】______your cancer risk as individuals.

单选题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 help 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 spend 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 manufactures 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 attracted 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 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. To help cut the waste and encourage intelligent manufacturers the simplest trick is to look for ultra-light package. 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.

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Should doctors ever lie to benefit their patient — to speed recovery or to conceal the approach of death? In medicine as in law, government, and other lines of work, the requirements of honesty often seem dwarfed by greater needs: the need to shelter from brutal news or to uphold a promise of secrecy; to expose corruption or to promote the public interest. What should doctors say, for example, to a 46-year-old man coming in for a routine physical checkup just before going on vacation with his family who, though he feels in perfect health, is found to have a form of cancer that will cause him to die within six months? Is it best to tell him the truth? If he asks, should the doctors deny that he is ill, or minimize the gravity of the illness? Should they at least conceal the truth until after the family vacation? Doctors confront such choices often and urgently. At times, they see important reasons to lie for the patient's own sake; in their eyes, such lies differ sharply from self-serving ones. Studies show that most doctors sincerely believe that the seriously ill patients do not want to know the truth about their condition, and that informing them risks destroying their hope, so that they may recover more slowly, or deteriorate faster, perhaps even commit suicide. As one physician wrote: "Ours is a profession which traditionally has been guided by a precept that transcends the virtue of uttering the truth for truth's sake, and that is 'as far as possible do no harm. " But the illusory nature of the benefits is now coming to be documented. Studies show that, contrary to the belief of many physicians, an overwhelming majority of patients do want to be told the truth, even about grave illness, and feel betrayed when they learn that they have been misled. We are also learning that truthful information, humanely conveyed, helps patients cope with illness: help them tolerate pain better, need less medicine, and even recover faster after surgery. There is urgent need to debate this issue openly. Not only in medicine, but in other professions as well, practitioners may find themselves repeatedly in difficulty where serious consequences seem avoidable only through deception. Yet the public has every reason to be wary of professional deception, for such practices are peculiarly likely to become deeply rooted, to spread, and to erode trust. Neither in medicine, nor in law, government, or the social sciences can there be comfort in the old saying, " What you don't know can't hurt you. "

单选题All around the world, lawyers generate more hostility than the members of any other profession—with the possible exception of journalism. But there are few places where clients have more grounds for complaint than America. During the decade before the economic crisis, spending on legal services in America grew twice as fast inflation. The best lawyers made skyscrapers—full of money, tempting ever more students to pile into law schools. But most law graduates never get a big-firm job. Many of them instead become the kind of nuisance-lawsuit filer that makes the tort system a costly nightmare. There are many reasons for this. One is the excessive costs of a legal education. There is just one path for a lawyer in most American states: a four-year undergraduate degree in some unrelated subject, then a three-year law degree at one of 200 law schools authorized by the American Bar Association and an expensive preparation for the bar exam. This leaves today's average law-school with $ 100 000 of debt on top of undergraduate debts. Law-school debt means that many cannot afford to go-into government or non-profit work, and that they have to work fearsomely hard. Reforming the system would help both lawyers and their customers. Sensible ideas have been around for a long time, but the state-level bodies that govern the profession have been too conservative to implement them. One idea is to allow people to study law as an undergraduate degree. Another is to let students sit for the bar after only two years of law school. If the bar exam is truly a stern enough test for a would-be lawyer, those who can sit it earlier should be allowed to do so. Students who do not need the extra training could cut their debt mountain by a third. The other reason why costs are so high is the restrictive guild-like ownership structure of the business. Except in the District of Columbia, non-lawyers may not own any share of a law firm. This keeps fees high and innovation slow. There is pressure for change from within the profession, but opponents of change among the regulators insist that keeping outsiders out of a law firm isolates lawyers from the pressure to make money rather than serve clients ethically. In fact, allowing non-lawyers to own shares in law firms would reduce costs and improve service to customers, by encouraging law firms to use technology and to employ professional managers to focus on improving firms' efficiency. After all, other countries, such as Australia and Britain, have started liberalizing their legal professions. America should follow.