阅读理解The Development of Both HIV And Its Cure As the number of people infected (传染) with the AIDS—causing HIV rose to more than 14 million worldwide and as new research showed that in the U.S. one of every 92 young men may be infected, a cure for the disease still remained an elusive(令人困惑的) dream. To help slow the spread of HIV to infants, the CDC in July called for all pregnant(怀孕的) women to be tested for the virus(毒素). The recommendation (推荐) stemmed (发展) from a. study that found that the risk that an HIV-infected woman will pass the virus on to her unborn child is cut by two-thirds if the mother receives the drug azidothymidine ( AZT) during pregnancy. The year was also marked by the first official recognition (认可)that treating HIV-infected people with a combination(结合) of antiviral(抗毒素的) drugs is superior to treating them with only AZT, a drug that had been the gold standard of treatment since the late 1980s. At an international conference in Copenhagen, a pane(专门小组)of scientists recommended that patients with the AIDS virus receive combination therapy, although there was still no consensus (一致)on when in the course of the disease the drugs should be started. In December the FDA approved the first of a long-awaited new class of AIDS drugs, called protease inhibitors , Physicians emphasized, however, that the new drug, saquinavir, is not a cure and must be taken in combination with other AIDS drugs. A glimmer(微光)of hope for a cure came when a team from the University of Washington reported in November that a new drug, PMPA, prevented monkeys from becoming infected by the monkey version of HIV even when the virus was injected(注射) directly into the animals. The year also provided the research community (界) , with a few more clues (线索) on how to attack HIV. In June researchers found that 70% of West African women infected with a slow-acting, less easily transmitted(传播)type of the virus were protected against infection by the faster-acting type, which was most common in the West. Earlier in the year hopes for lifesaving(救命的) AIDS treatments or vaccines (痘苗) were also bolstered (支持) by an intriguing(激起好奇心的)—and hotly debated—report that at least two children who had been born infected with the AIDS virus later became free of it. Despite the mammoth(巨大的) swath(长而宽的地带) of destruction(破坏) that AIDS has cut around the world since it first surfaced(升到水面) just 15 years ago, it took a much rarer(稀有的)—and much swifter(反应快的)—killer, the Ebola virus, to jolt (唤起) the public out of its complacency(自满) toward the threat of emerging infectious (感染性的) diseases.

阅读理解Interview The importance and focus of the interview in the work of the print and broadcast journalist are reflected in several books that have been written on the topic. Most of these books, as well as several chapters, mainly in, but not limited to, journalism and broadcasting handbooks and reporting texts, stress the "how to" aspects of journalistic interviewing rather than the conceptual aspects of the interview, its context, and implications. Much of the "how to" material is based on personal experiences and general impressions. As we know, in journalism as in other fields, much can be learned from the systematic study of professional practice. Such study brings together evidence from which broad generalized principles can be developed. There is, as has been suggested, a growing body of research literature in journalism and broadcasting, but very little significant attention has been devoted to the study of the interview itself. On the other hand, many general texts as well as numerous research articles on interviewing in fields other than journalism have been written. Many of these books and articles present the theoretical and empirical (经验的) aspects of the interview as well as the training of the interviewers. Unhappily, this plentiful general literature about interviewing pays little attention to the journalistic interview. The fact that the general literature on interviewing does not deal with the journalistic interview seems to be surprising for two reasons. First, it seems likely that most people in modem Western societies are more familiar, at least in a positive manner, with journalistic interviewing than any other form of interviewing. Most of us are probably somewhat familiar with the clinical interview, such as that conducted by physicians and psychologists. In these situations the professional person or interviewer is interested in getting information necessary for the diagnosis and treatment of the person seeking help. Another familiar situation is the job interview. However, very few of us have actually been interviewed personally by the mass media, particularly by television. And yet, we have a vivid acquaintance with the journalistic interview by virtue of our roles as readers, listeners, and viewers. Even so, the understanding of the journalistic interview, especially television interview, requires thoughtful analyses and even study, as this book indicates.

阅读理解Communication Problems After 20 years of research, my colleagues and I have discovered that all communication involves our bodies, sometimes profoundly. While we speak with words, we also speak with every fiber of our being. This "language of the heart" is integral to the health and emotional life of all of us. We found that even a pleasant chat about the weather can affect the cardiovascular (心血管性的) system , particularly blood pressure. The traditional way of taking blood pressure—with a stethoscope (听诊器)—meant that the patient had to keep silent, and this silence prevented clinicians from discovering the link between communication and blood pressure. The breakthrough in our studies occurred in 1977, when we met Ed, a typical hypertensive patient who came to the University of Maryland''s Psychophysiology Center for treatment. We hooked up Ed to a new com?puter that could continuously monitor blood pressure. We found that his pressure immediately increased every time he spoke, even if he was discussing the most neutral topic. What was more surprising was that Ed was unaware of these changes. This finding so intrigued us we began testing others. The results were the same. Blood pressure and heart rate rose rapidly whenever people talked. We asked students to read aloud from a bland(乏味的)text. Their blood pressure and heart rate rose rapidly every time. We tested 38 deaf-mute volunteers. When these people signed, their blood pressure also increased. This confirmed our suspicion that it was the act of communication, not just talking, that led to these changes. Most normal talk is a seesaw (一上一下的动作). The rising of blood pressure when one talks is balanced by a rapid lowering of pressure when one listens. But the rhythm is out of synclinal hypertensives. They fluently fail to listen; they are on guard, defensive. So their pressure stays up. The benefits of listening are seen in the "orienting reflex," discovered by Pavlov. When a dog hears a sound or sees movement, it will stop all activity and cock its head. Another Russian scientist, E.N. Soklor, noticed that the dog''s heart rate slows. A similar response occurs in people too—and it lowers blood activities: reading out loud, staring at a blank wall and watching fish in a tank. Blood pressure washing test when the people spoke. But it was lowest when they watched the fish, rather than when they simply sat and relaxed. Whether watching fish or listening to another person, attending calmly to the world outside yourself helps lower blood pressure. When I got hypertensives to listen undefensively, their blood pressure often fell dramatically. Why do some people find talking so stressful, and listening so difficult? I tested some healthy newborns. When they cried, their blood pressure often doubled. We began thinking about pressure surges in hypertensives as similar to the changes when a baby cries. Though calm on the surface while talking, their bodies are screaming to be heard. For these people, communication becomes a desperate but hidden struggle. Inside their adult bodies is a baby crying, terrified because no one can hear it. So how can we enjoy conversation yet keep blood pressure down? By listening more, by breathing regularly while talking, by alternating between talking and paying attention to what the other person is saying. But what can hypertensives do? Treatments that teach them to focus on their relationship and how to communicate in a relaxed way can be a start toward health. We can understand and cope with illness only when we view ourselves as part of a complex world beyond the confines of our own individual skin. The response of our hearts, blood vessels and muscles when we communicate with spouse, children, friends and colleagues is as vital to our cardiovascular health as is exercise or diet.

阅读理解Knitting My mother knew how to knit (编织), but she never taught me. She assumed, as did many women of her generation, that knitting was no longer a skill worth passing down from mother to daughter. A combination of feminism (女权主义) and consumerism (浪费主义) made many women feel that such homely accomplishments were now out of date. My Grandmother still knitted, though, and every Christmas she made a pair of socks for my brother and me, of red wool. They were the ones we wore under our ice skates (冰鞋) , when it was really important to have warm feet. Knitting is a nervous habit that happens to be productive. It helped me quit smoking by giving my hands something else to do. It is wonderful for depression because no matter what else happens, you are creating something beautiful. Time spent in front of the television or just sitting is no longer time wasted. I love breathing life into the patterns. It''s true magic, finding a neglected, dog-eared old book with the perfect snowflake design, buying the same Germantown wool my grandmother used, in the exact blue to match my daughter''s eyes, taking it on the train with me every day for two months, working enthusiastically to get it done by Christmas, staying up late after the stockings are filled to sew in the sleeves and weave in the ends. Knitting has taught me patience. I know that if I just keep going, even if it takes months, there will be a reward. When I make a mistake, I know that anger will not fix it, that I just have to go back and take out the stitches (针脚) between and start over again. People often ask if I would do it for money, and the answer is always a definite no. In the first place, you could not pay me enough for the hours I put into a sweater. But more important, this is an activity I keep separate from such considerations. I knit to cover my children and other people I love in warmth and color. I knit to give them something earthly that money could never buy. Knitting gives my life an alternative rhythm to the daily deadline. By day I can write about Northern Ireland or the New York City Police Department and get paid for it, but on the train home, surrounded by people with laptops, I stage my little rebellion. I take out my old knitting bag and join the centuries of women who have knitted for love.

阅读理解A tragedy like the sinking of the Titanic never happened again.

阅读理解Interferon For several years, scientists have been testing a substance called interferon (干扰素),a potential wonder drug that is proving to be effective in treating a variety of ailments, including virus infections, bacteria infections, and tumors. To date, the new drug has provoked no negative reaction of sufficient significance to discourage its use. But in spite of its success, last year only one gram was produced in the entire world. The reason for the scarcity lies in the structure of interferon. A species specific protein, the interferon produced from one animal species cannot be used in treating another animal species. In other words, to treat human beings, only interferon produced by human beings may be used. The drug is produced by infecting white blood cells with a virus. Fortunately, it is so potent that the amount given each patient per injection is very small. Unlike antibiotics(抗菌素), interferon does not attack germs directly. Instead, it makes unaffected cells resistant to infection, and prevents the multiplication of viruses within cells. As you might conclude, one of the most dramatic uses of interferon has been in the treatment of cancer. Dr. Hans Strander, research physician at Sweden''s famous Karolinska Institute, has treated more than one hundred cancer patients with the new drug. Among a group of selected patients who had undergone surgical procedures for advanced cancer, half were given conventional treatments and the other half were given interferon. The survival rate over a three-year period was 70 percent among those who were treated with interferon as compared with only 10 to 30 percent among those who had received the conventional treatments. In the United States, a large-scale project supported by the American Cancer Society is now underway. If the experiment is successful, interferon could become one of the greatest medical discoveries of our time.

阅读理解The Gene Industry Major companies are already in pursuit of commercial applications of the new biology. They dream of placing enzymes in the automobile to monitor exhaust and send data on pollution to a microprocessor that will then adjust the engine. They speak of what the New York Times calls "metal—hungry microbes that might be used to mine valuable trace metals from ocean water". They have already demanded and won the right to patent new lifeforms. Nervous critics, including many scientists, worry that there is corporate, national, international, and inter-scientific rivalry in the entire biotechnological field. They create images not of oil spills, but of "microbe spills" that could spread disease and destroy entire populations. The creation and accidental release of extremely poisonous microbes, however, is only one cause for alarm. Completely rational and respectable scientists are talking about possibilities that stagger the imagination. Should we breed people with cow-like stomachs so they can digest grass and hay, thereby relieving the food problem by modifying us to eat lower down on the food chain? Should we biologically alter workers to fit the job requirement, for example, creating pilots with faster reaction times or assembly-line workers designed to do our monotonous work for us? Should we attempt to eliminate "inferior" people and breed a " super-race"? ( Hitler tried this, but without the genetic weaponry that may soon issue from our laboratories. ) Should we produce soldiers to do our fighting? Should we use genetic forecasting to pre-eliminate "unfit" babies? Should we grow reserve organs for ourselves, each of us having, as it were, a " savings bank" full of spare kidney, livers or hands? Wild as these notions may sound, every one has its advocates (and opposers) in the scientific community as well as its striking commercial application. As two critics of genetic engineering, Jeremy Rifkin and Ted Howard, state in their book Who Should Play God? " Broad Scale genetic engineering will probably be introduced to America much the same way as assembly lines, automobiles, vaccines, computers and all the other technologies. As each new genetic advance becomes commercially practical, a new consumer need will be exploited and a market for the new technology will be created."

阅读理解Hints for Reading Practice 1. Most of us can find 15 minutes or half an hour each day for some specific regular activity. For example, one famous surgeon always made it a rule to spend at least 15 minutes on general reading before he went to sleep each day. Whether he went to bed at 10 p. m. or 2. 30 a. m. made no difference. 2. Nearly all "Speed Reading" courses have a "pacing"——some timing device which lets the students know how many words a minute he is reading. You can do this simply by looking at your watch every 5 or 10 minutes and noting down the page number you have reached. 3. Obviously there is little point in increasing your reading speed if you do not understand what you are reading. If you find you have lost the thread of the story, or you cannot remember clearly the details of what was said, re-read the section or chapter. 4. Take four or five pages of an interesting book you happen to be reading at the time. Read them as fast as you possibly can. Do not bother about whether you understand or not. If you keep doing this "lightning speed" reading for an extended period of time, you will usually find that your "normal" speed has increased. 5. Most paragraphs in an article have a "a topic sentence" which expresses the central ideas. The opening paragraph often suggests the general direction and content of the piece, while paragraphs that follow expand or support the first. The closing paragraph often summarizes the very essence of what has been said. A. The Organization of an Article B. An Effective Way to Increase Reading Speed C. Set Aside Time Each Day D. Check Your Comprehension E. Check Your Reading Speed F. Hints for Reading Practice

阅读理解The Grand Canyon Standing on the rim of the Grand Canyon(大峡谷), gazing across this giant wound in the Earth''s surface, a visitor might assume that the canyon had been caused by some ancient convulsion(震动). In fact, the events that produced the canyon, far from being sudden and catastrophic, simply add up to the slow and orderly process of erosion. Many millions of years ago, the Colorado Plateau in the Grand Canyon area contained 1,000 more feet of rock than it does today and was relatively level. The additional material consisted of some 14 layered formations of rock. In the Grand Canyon region these layers were largely worn away over the course of millions of years. Approximately 65 million years ago the plateau s flat surface in the Grand Canyon area bulged upward from internal pressure, geologists refer to this bulging actions upwarding (弯曲上升) ; it was followed by a general elevation of the whole Colorado Plateau, a process that is still going on. As the plateau gradually rose, shallow rivers that winded across it began to run more swiftly and cut more definite courses. One of these rivers , located east of the upward, was the ancestor of the Colorado. Another river system, called the Hualapai, flowing west of the upward, extended itself eastward by cutting back into the upward, it eventually connected with the ancient Colorado and captured its waters. The new river then began to carve out the 277-mile-long trench that eventually became the Grand Canyon. Geologists estimate that this initial cutting action began no earlier than 10 million years ago. Since then, the Canyon forming has been cumulative. To the corrosive force of the river itself have been added other factors. Heat and cold, rain and snow, along with the varying resistance of the rocks, increase the opportunities for erosions. The Canyon walls crumble, the river acquires a cutting tool. Tons of debris, rainfall running off the high plateau creates feeder streams that carreside canyons. Pushing slowly backward into the plateau, the side canyons expose new rocks, and the pattern of erosion continues.

阅读理解Cancer The popular TV variety-show host was grim but calm. He faced the cameras and said bluntly: "I have cancer." Masataka Itsumi''s disclosure may be the latest sign that the shame associated with cancer is finally breaking down in a country where, unlike the United Sates, the topic has traditionally been taboo. Cancer is the country''s No.1 killer, chaining more than 230,000 lives a year. Despite the number of people affected, the subject has long been concealed in secrecy and silence. As a rule, Japanese are reluctant to tell anyone other than family if they have cancer. And doctors often lie to patients about a cancer diagnosis, fearing they would be depressed and weakened by the truth. Polls indicate that most people would prefer to be told if they have cancer. But health authorities have estimated as few as one in five cancer patients is given a truthful diagnosis. "The patient is very afraid to hear of having cancer, so many doctors just don’t tell," said one doctor. " But if we don’t tell the truth, it''s bad for the relationship between doctor and patient. So I think this is beginning to change". He said he believed the intense public interest in the Itsumi case reflected pent-up curiosity and concern about the subject. There are other signs of greater openness in confronting cancer. Support groups for cancer victims, once unknown, have sprung up. The plot of a recent film revolved around a man with cancer. An unusually powerful television advertisement, appealing for bone-marrow donations, features a young woman who has since died of leukemia. But secrecy about cancer is still common. In Japan, serious illness is considered embarrassing. People worry about causing suffering and expense for their families, or discomforting their colleagues. Itsumi, in fact, began his news conference by apologizing. Other factors contribute to the taboo on talk about cancer. There is a cultural tendency toward restraint on discussing personal matters and stoicism in facing problems. Even if patients sense something is very wrong despite a good diagnosis, most do not press their doctors or seek a second opinion. Doctors are granted deep respect in a society that discourages questioning authority.

阅读理解Vending Vending is such an up-to-date concept, in providing products where and when customers want them, that it is hard to believe that it made its first appearance in Egyptian Temples back in 215 B. C. Vending has benefited from that long history and is now poised to meet the needs of the 21st century consumer. Current day pressures mean that we are all time-starved and the ready availability of a drink and a snack at the right temperature just where we want. It is the convenient luxury that helps to keep stress at bay and provides a few more minutes at the desk or in the gym. At work, those extra minutes spent making tea or coffee by hand really add up. Research conducted by the NOP ( National Opinion Poll) for the Association showed that the average time spent on this by employees over and above formal lunch and tea breaks is 45 minutes per day. That equates to a firm employing 50 people losing up to 37 man everyday, a real hole in productivity! It''s not just in the workplace, though, that the benefits of vending can be enjoyed. More and more major household brands are seeing vending as an ideal route to the customer for their products because the vending machine can be trusted to be ready to serve whenever there is a demand. Machines are now familiar sights at airports, garage forecourts, leisure sites, railway stations and anywhere else that people gather, allowing consumers to put together an instant picnic. It''s no surprise, therefore, that consumers are currently spending at the rate of some ￡1 billion per year through the slots of vending machines now that 10 million drinks are vended into cups every day.

阅读理解Nurses The physicians in a hospital form the core of the medical staff. But they could not provide effective medical care to their patients without the help of numerous other medical workers. From the angle of the patients, the nursing staff is particularly important. Nurses are usually in close contact with patients as long as they are in the hospital. A nurse does not study for as many years as a doctor. However, each must be equally trained. Caring for sick persons requires a great deal of patience and concern. Most nurses work long days, and they often must work at odd hours or during the night. The nursing staff in a hospital is usually quite large and various. Nursing services, after all, must be provided on a 24-hour basis. There are professional (专业的) nurses, practical nurses, nurses aids, and orderlies (勤杂工). The general term nurse refers to a person trained to offer bedside care to sick persons. Under the supervision (管理) of the head nurse, the nursing staff in a hospital ward must attend to patients'' needs. This responsibility continues around the clock, and so nurses must work in shifts. A shift is a period of duty, usually eight hours in length. The nurses on the ward rotate (轮换) their shifts. Some take turns working night duty; others work odd shifts. All of them work out of a central area on the ward called the nurses station. A nurse must always be on her guard. She can never afford to be careless. This is true in all nursing situations , but it is especially true in the intensive care unit. Patients under intensive care are critically ill, and they must be monitored at all times. The nurses who do intensive care duty have one of the most demanding jobs in the hospital.

阅读理解Ashley''s Message of Hope 1. The birth of any child raises many questions. Will she have my eyes, her dad''s smile? What will she want to be when she grows up? But the biggest question for every parent is "Will she be healthy?" 2. Our daughter, Ashley Elizabeth Naylor, was born on August 12, 1988. We had a lot of mixed emotions the day of her birth, but mainly we felt fear and despair. The doctors suspected complications (并发病) , which led to a cesarean section (剖腹产手术) , but the exact problem was not known. Two weeks after her birth, chromosome (染色体) analysis revealed cat cry syndrome. The doctors were uncertain about how the disease would develop. This was a rare disorder, we were told, and little could be offered to help our daughter. The doctors used the words "profoundly slow," which cut like a knife through our hearts and our hopes. It wasn’t until a few years later that we realized how little the medical community actually knew about cat cry syndrome and especially about our little girl! 3. Ashley defied all the standard medical labels, as well as her doctor''s expectations. Her spirit and determination enabled her to walk with the aid of a walker (学步车) and express herself using sign language and a communication device. With early intervention and education at United Services for the Handicapped, Ashley found the resources and additional encouragement she needed to succeed. In return, Ashley freely offered one of her best loved and sought after gifts—her embraces. Her bright eyes and glowing smile captured the hearts of everyone she met. 4. In May of 1992, Ashley''s small body could no longer support the spirit that inspired so many. She passed away after a long battle with pneumonia (肺炎). Her physical presence is gone, but her message remains: hope. 5. If you are a parent faced with similar profound questions after the birth of your child, do not assume one doctor has all the answers. Search for doctors who respect your child enough to talk to her, not just about her. Above all, find an agency or a school that can help you give your child a chance to succeed. Early education for your child and support for yourself are crucial. 6. If you are a student in a health field, become as knowledgeable as possible and stay current with the latest research, but most importantly, be sensitive to those who seek your help. Each word you speak is taken to heart, but hope can make all the difference in a family''s future. A. Helping a Doctor to Succeed B. Hearts Saddened by a Rare Disorder of Our Baby Girl C. Sympathy and Knowledge Shown by Medical Students D. Message Left Behind by a Short but Inspiring Life E. Helping Your Unlucky Kid to Succeed F. Wonders Made by Our Sick but Charming Little Girl

阅读理解Old Mothers’ Children Have Higher Diabetes (糖尿病) Risk Children of older mothers run a higher risk of developing insulin-dependent (胰岛素依赖型的) diabetes, the British Medical Journal said. "A strong association was found between increasing maternal (母亲的) age at delivery and risk of (insulin-dependent) diabetes in the child. Risk was highest in firstborn children and decreased progressively with higher birth order," Professor Edwin Gale and colleagues at Southmead Hospital in Bristol said. Diabetes is a serious, incurable, lifelong disease characterized (以......作为特性) by all inability to control the amount of sugar in the blood. Insulin-dependent diabetes, which mainly affects children, is treated by administering the hormone insulin. Gale looked into 1,375 families in the Oxford area where one or more children had diabetes and found that the risk of a child developing insulin-dependent diabetes increased by 25 percent for each five-year band of the mothers age. The risk of developing diabetes was also linked to the age of the father. For every five-year band of the father''s age the risk of the child developing diabetes increased by nine percent. The risk of diabetes was high?est among the firstborn children of mothers who started their families late and the risk decreased by about 15 percent for each subsequent child, the BMJ said. The older the mother, the earlier the start of insulin-dependent diabetes in the child. Other studies have already shown that children born to older mothers, over the age of 35, have an increased risk of diabetes but this study is the first to establish that risk increases continuously in relation to increasing maternal age, Dr. Polly Bingley of Southmead Hospital told Reuters (路透社). The new study is the first to show that risk is related to birth order. The study also partly explains increasing diabetes. Between 1970 and 1996 the proportion of children born to mothers aged between 30 and 34 increased to 28 percent from 15 percent and this could account for rising numbers of childhood diabetes patients, the scientists said in the alarming increase in the rate of (insulin-dependent) diabetes among children in recent years. "This study may well provide a clue to the understanding of this problem. It is most likely that there are a number of factors to explain the increase," Diabetes UK said. There are some 1.4 million diagnosed diabetes sufferers in Britain, the charity Diabetes UK said. Of these 1.4 million sufferers there are 20,000 people under age 20 who suffer from insulin-dependent diabetes.

阅读理解A Hierarchy of Hormones All of the cells in a particular plant start out with the same complement of genes. How then can these cells differentiate and from structures as different as roots, stems, leaves, and fruits? The answer is that only a small subset of the genes in a particular kind of cell are expressed, or turned on, at a given time. This is accomplished by a complex system of chemical messengers that in plants include hormones and other regulatory molecules. Five major hormones have been identified; auxin (生长素), abscisic acid(脱落酸) ,cytokinin(细胞激动素), hetylene(乙烯), and gibberellin(赤霉素). Studies of plants have now identified a new class of regulatory molecules called oligosaccharins. Unlike the oligosaccharins, the five well-known plant hormones are pleiotropic (多向性的) rather than specific, that is, each has more than one effect on the growth and development of plants. The five have so many simultaneous effects that they are not very useful in artificially controlling the growth of crops. Auxin, for instance, stimulates the rate of cell elongation(拉长), causes shoots to grow up and roots to grow down, and inhibits the growth of lateral(侧面的) shoots. Auxin also causes the plant to develop a vascular(维管的) system, to from lateral roots, and to produce ethylene. The pleiotropy of the five well-studied plant hormones is somewhat analogous (类似的) to that of certain hormones in animal. For example, hormones from the hypothalamus (下五脑) in the brain stimulate the anterior(前面的) lobe of the pituitary gland to synthesize and release many different hormones, one of which stimulates the release of hormones from the adrenal(肾上腺的) cortex(皮质|). These hormones have specific effects on target organs all over the body. One hormone stimulates the thyroid (甲状腺的) gland, for example, another the ovarian (子房)follicle cells, and so forth. In other words, there is a hierarchy(统治集团) of hormones. Such a hierarchy may also exist in plants. Oligosaccharins are fragments of the cell wall released by enzymes (酶): different enzymes release different oligosaccharins. There are indications that pleiotropic plant hormones may actually function by activating the enzymes that release these other, more specific chemical messengers from the cell wall.

阅读理解Bathing In the Sea Bathing in the sea in England a hundred years ago was not quite the light-hearted amusement that it is today. There are no running down from the hotel to the beach in a bath robe(长袍) , no sunbathing, or lying about on the sands in bathing-dresses after the dip. Everything had to be done in an orderly and extremely polite manner. Mixed bathing was not allowed anywhere. Men and women each had their separate part of the beach, and they were not supposed to meet in the water. Bathing clothes were also closely controlled. Men usually wore simple bathing drawers and no more, but women were obliged to wear thick, cumbersome woolen garments that covered them completely from head to foot. These satisfied the demands of modesty, but they must have been extremely uncomfortable for swimming. Even thus decently covered, women were not supposed to show themselves on the beach while in bathing attire(浴衣). They had to wait their turn for a bathing machine, a sort of wooden cabin on wheels which was drawn right down to the waters edge by horses. On its seaward side a sort of hood or canopy(罩盖) stretched outwards and downwards over the water, completely hiding the bather until she was actually in the sea, There was a bathing woman in attendance, part of whose duty was to dip, in other words, to seize the bather as soon as she emerged and dip her forcibly under water two or three times. This was supposed to be for the benefit of her health, and no doubt it was all right in the hands of the gentle. But most bathing women were the reverse of gentle, and to be dipped by them must have been a strenuous form of exercise.

阅读理解More Than 8 Hours Sleep Too Much of a Good Thing Although the dangers of too little sleep are widely known, new research suggests that people who sleep too much may also suffer the consequences. Investigators at the University of California in San Diego found that people who clock up 9 or 10 hours each weeknight appear to have more trouble falling and staying asleep, as well as a number of other sleep problems, than people who sleep 8 hours a night. People who slept only 7 hours each night also said they had more trouble falling asleep and feeling refreshed after a night’s sleep than 8-hour sleepers. These findings, which DL Daniel Kripke reported in the journal Psychosomatic Medicine, demonstrate that people who want to get a good night''s rest may not need to set aside more than 8 hours a night. He added that" it might be a good idea" for people who sleep more than 8 hours each night to consider reducing the amount of time they spend in bed, but cautioned that more research is needed to confirm this. Previous studies have shown the potential dangers of chronic shortages of sleep—for instance, one report demonstrated that people who habitually sleep less than 7 hours each night have a higher risk of dying within a fixed period than people who sleep more. For the current report, Kripke reviewed the responses of 1,004 adults to sleep questionnaires, in which participants indicated how much they slept during the Week and whether they experienced any sleep problems. Sleep problems included waking in the middle of the night, arising early in the morning and being unable to fall back to sleep, and having fatigue interfere with day-to-day functioning. Kripke found that people who slept between 9 and 10 hours each night were more likely to report experiencing each sleep problem than people who slept 8 hours. In an interview, Kripke noted that long sleepers may struggle to get rest at night simply because they spend too much time in bed. As evidence, he added that one way to help insomnia is to spend less time in bed. " It stands to reason that if a person spends too long a time in bed, then they’11 spend a higher percentage of time awake, "he said. A. Keprike’s research tool B. Dangers of Habitual shortages of sleep C. Criticism on Kripke''s report D. A way of overcoming insomnia E. Sleep problems of long and short sleepers

阅读理解Nurses who work in the intensive care unit in a hospital are better trained than other nurses.

阅读理解Flu Shots Or Not? It sounded like a good idea when New York City''s mayor, Rudollph Giuliani, advised New Yorkers recently to get a flu shot. After all, 20,000 Americans each year die of influenza. And this year in particular, the mayor suggested, getting a flu shot might be an especially good idea, since it could help doctors distinguish between flu and the deadly inhalational (吸入的) form of anthrax (炭疽). How? Both anthrax and flu exhibit strikingly similar symptoms—fever, chills and muscle aches—in the early days of the infection. Physicians would be quick to suspect anthrax in anyone who was vaccinated (接种疫苗) against flu and still developed fever and chills. That would give them a better chance to identify any new victims of terror while their infection was still in its earliest, most treatable stages. Or so the mayor''s reasoning went. Unfortunately, there are a couple of problems with his logic. For one thing, getting vaccinated against influenza doesn’t guarantee you wont get sick. Although highly effective, the flu vaccine (疫苗) protects against only the dominant types of the disease and even then does not provide 100% protection. It takes a couple of weeks for your body to respond to the vaccine with a sufficient number of antibodies (抗体). Each year thousands of Americans who get the vaccine nevertheless still get the flu. There are also plenty of reasons you might develop fever, chills and muscle aches that have nothing to do with either anthrax or flu. Indeed, doctors estimate that more than 80% of all flu like illnesses each winter are caused by other groups of viruses. Getting vaccinated against flu cant protect you against suffering from these other illnesses. In the worst case, asking all healthy adults to get vaccinated could actually have the opposite effect to the one intended, leading to even more deaths if it means we run out of shots for those who are most vulnerable to the infection. Already there have been delays in getting this year''s shipment of vaccine to clinics and doctors'' offices. Those who should be at the front of the line include folks who are 65 or older, nursing-home residents and adults and children with chronic health problems as well as anyone who cares for or lives with such people. Flu shots are also important for men and women whose immune system is weakened by HIV (艾滋病病毒) or other conditions. The best reason to get the flu vaccine is that it protects against most flus — not that you''re worried about getting anthrax. While inhalational anthrax has killed only five people so far, many more could be at risk from flu-related complications. There''s no need to worsen the tragedy by making this year''s influenza epidemic any worse.

阅读理解Euthanasia: a Heatedly Debated Topic "We mustn''t delay any longer...?swallowing(吞咽) is difficult...and breathing, that''s also difficult. Those muscles are weakening too...we mustn''t delay any longer." These were the words of Dutchman(荷兰人) Cees van wendel de Joode asking his doctor to help him die. Affected with a serious disease, van Vendel was no longer able to speak clearly and he knew there was no hope of recovery and that his condition was rapidly deteriorating. Van Venders last three months of life before being given a final, lethal injection by his doctor were filmed and first shown on television last year in the Netherlands. The programme has since been bought by 20 countries and each time it is shown, it starts a nationwide debate on the subject. The Netherlands is the only country in Europe which permits euthanasia (安乐死) , although it is not technically legal there. However, doctors who carry out euthanasia under strict guidelines introduced by the Dutch Parliament(议会) two years ago are usually not prosecuted. The guidelines demand that the patient is experiencing extreme suffering, that there is no chance of a cure, and that the patient has made repeated requests for euthanasia. In addition to this, a second doctor must confirm(证实) that these criteria have been met and the death must be reported to the police department. Should doctors be allowed to take the live of others? Dr. Wilfred Van Oijen, Cees van Vendel''s doctor, explains how he looks at the question: "Well, it''s not as if I in planning to murder a crowd of people with a machine gun. In that case, killing is the worst thing I can imagine. But that''s entirely different from my work as a doctor. I care for people and I try to ensure that they don’t suffer too much. That''s very different thing. " Many people, though, are totally against the practice of euthanasia. Dr. Andrew Ferguson, Chairman of the organization Healthcare opposed to Euthanasia, says that "in the vast majority of euthanasia cases , what the patient is actually asking for is something else. They may want a health professional to open up communication for them with their loved ones or family—there''s nearly always another question behind the question." Britain also has a strong tradition of hospices—special hospitals which care only for the dying and their special needs. Cicely Saunders, President of the National Hospice Council and a founder member of the hospice movement, argues that euthanasia doesn''t take into account that there are ways of caring for the dying. She is also concerned that allowing euthanasia would undermine the need for care and consideration of a wide range of people; "It''s very easy in society now for the elderly, the disabled (伤残的) and the dependent to feel that they are burdens, and therefore that they ought to opt(脱离) out. I think that anything that legally allows the shortening of life does make those people more vulnerable (脆弱的)." Many find this prohibition of an individual''s right to the paternalistic (家长式的). Although they agree that life is important and should be respected, they feel that the quality of life should not be ignored. Dr. Van Oijen believes that people have the fundamental right to choose for themselves if they want to die: "What those people who oppose euthanasia are telling me is that dying people haven’t the right. And that when people are very ill, we are all afraid of their death. But there are situations where death is a friend. And in those cases, why not?" But "why not?" is a question which might cause strong emotion. The film showing Cees Van Vendel''s death was both moving and sensitive. His doctor was clearly a family friend; his wife had only her husband''s interests at heart. Some, however, would argue that it would be dangerous to use this particular example to support the case for euthanasia. Not all patients would receive such a high level of individual care and attention.