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Hypertension is the medical term for persistent and sustained high blood pressure. It is one of the most (51) forms of heart disease. An understanding of blood pressure in (52) , healthy individuals is necessary in order to understand hypertension.Blood pressure is simply the force (53) against the walls of the body’s arteries (血管) as blood flows through. The force, produced primarily by the pumping (54) of the heart, is essential for the (55) of the blood and its life-supporting nutrients(营养) to all parts of the body. Every time the heart (56) , called a systole, blood pressure increases. When the heart relaxes (57) beats(diastole), the pressure decreases. The normal systolic pressure of a person at vest is between 100 to 140, and the normal diastole is 60 to 90. Blood-pressure readings are expressed by both (58) , with the systolic over the diastolic: for example, 140/90.As these ranges suggest, there is a wide (59) of blood pressure for healthy people. Also, blood pressure (60) for healthy people during different times of the day and under different. (61) . It is lower when an individual is asleep than when he is excited or exerting himself physically. Therefore, a single blood-pressure reading above 140/90 does not (62) abnormality. When the pressure is continuously (63) , a person is considered to be suffering from hypertension.Hypertension is a stealthy(隐秘的) problem: a physician can discover it easily enough, but not a patient. (64) elevations, for example, may produce headaches, dizziness, fatigue, and weakness. But the patient is not likely to (65) these symptoms as having any other source than the increased elevation. 55（）
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FoodThe U. S. food supply is the most varied and abundant in the world. Americans spend a smaller share of their disposable income on food than citizens of any other country and choose from an average of 50,000 different food products on a typical outing to the supermarket. In 1994, the fowl supply provided an estimated 3,800 calories per person per day, enough to supply every American with more than one and a half times their average daily energy needs. Given this abundance, few of the Nations resources have traditionally been devoted to measuring or reducing food waste.In recent years, growing concern about hunger, resource conservation, and the environmental and economic costs associated with food waste have raised public awareness of food loss. This in turn has accelerated public and private efforts to make better use of available, food supplies by recovering safe and nutritious food that would otherwise be wasted.Of course, not all food that is lost is suitable for consumption. Some losses like the condemnation of diseased animals at the slaughtering house (屠宰场), or the discard of rotten fruit from the produce shelf at the supermarket are necessary to ensure the safetyand health of the U. S. food supply. Such foods are not recoverable for human use.Likewise, plate fragments are appropriately discarded at eating establishments out of health considerations. In addition, not all food that is lost is economically recoverable. Food recovery efforts are often limited by financial restraints that make it difficult to match recovered food with potential recipients.Nevertheless, large quantities of healthy, edible food are lost at every stage of the marketing system. Example of such losses include meats, bread, and other foods prepared by a restaurant or hotel but never served and the discard of defected or over-ripe .produce, which maybe difficult to sell out for some reasons, but are otherwise nutritious and safe. Discarding over-ripe produce is necessary for restaurants.()
High Stress May Damage Memory According to a report issued in May 1998, elderly people who have consistently high blood levels of cortisol don’t score as well on memory tests as their peers with lower levels of the stress hormone. What’s more, high levels of cortisol are also associated with shrinking of the hippocampus, a region of the brain that plays a key role in learning and memory. The findings suggest that even cortisol levels in the normal, "healthy" range can actually acceIerate brain aging. The study results "now provide substantial evidence that long-term exposure to adrenal stress hormones may promote hippocampal aging in normal elderly humans", write Nada Porter and Philip Landfield of the University of Kentucky in Lexington in their editorial. Cortisol is a hormone released in response to stress by the adrenal glands, which sit on top of the kidneys. Over a 5 to 6-year period. Dr. Sonia Lupien and his colleagues measured 24-hour cortisol levels in 51 healthy volunteers, most of whom were in their 70s. Despite wide variation in cortisol levels, the participants could be divided into three subgroups: those whose cortisol progressively increased over time and was currently high (increasing/high); those whose cortisol progressively increased over time and was currently moderate (increasing/moderate); and subjects whose cortisol decreased, but was currently moderate (decreasing/moderate). The researchers tested the volunteers’ memory on six people in the increasing/high category and five people in the decreasing/moderate group. The groups did not differ on tests of immediate memory, but the increasing/high cortisol group had other memory problems compared with those in the decreasing/moderate group. The researchers also found that the total volume of the hippocampus in those in the increasing/high group was 14% lower than those in the decreasing/moderate group, although there were no differences in other brain regions. The results suggest that " ... brain aging can be accelerated by levels of adrenal hormones that are not generally regarded as pathological and that variation within this normal range is related to variation in the rate of brain aging," write Porter and Landfield. "This further suggests that chronic stress may accelerate the worsening of hippocampus. \ Porter and Landfield’s research shows that______.
Youth Emancipation in Spain The Spanish Government is so worried about the number of young adults still living with their parents that it has decided to help them leave the nest. Around 55 percent of people aged 18-34 in Spain still sleep in their parents’ home, says the latest report from the country’s state-run Institute of Youth. To coax(劝诱) young people from their homes, the Institute started a "Youth Emancipation(解放)" programme this month. The programme offers guidance in finding rooms and jobs. Economists blame young people’s family dependence on the precarious(不稳定的)labour market and increasing housing prices. Housing prices have risen 17 percent a year since 2000. Cultural reasons also contribute to the problem, say sociologists(社会学家). Family ties in south Europe—Italy, Portugal and Greece—are stronger than those in middle and north Europe, said Spanish sociologist Almudena Moreno Minguez in her report "The Late Emancipation of Spanish Youth: Key for Understanding". "In general, young people in Spain firmly believe in the family as the main body around which their private. life is organized," said Minguez. In Spain— especially in the countryside, it is not uncommon to find entire groups of aunts, uncles, cousins, nieces and nephews(外甥/侄子) all living on the same street. They regularly get together for Sunday dinner. Parents’ tolerance is another factor. Spanish parents accept late-night partying and are wary of setting bedtime rules. "A child can arrive home at whatever time he wants. If parents complain he’ll put up a fight and call the father a fascist," said Jos6 Antonio Gomez Yanez , a sociologist at Carlos III University in Madrid. Mothers’ willingness to do children’s household chores(家务) worsens the problem. Dionisio Masso, a 60-year-old in Madrid, has three children in their 20s. The eldest, 28, has a girlfriend and a job. But life with mum is good. "His mum does the wash and cooks for him; in the end, he lives well," Masso said. Young people’s family dependence can be attributed to all the following factors EXCEPT
地方政府债券一般采用由财政厅统一代为发行和兑付的方式管理。( )
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