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    Have you ever wondered why the roots of the plants always know which way to grow—into the soil but not above it? Some British scientists have recently solved this mystery.    

      It turns out that roots have special hairs that tie them into the soil and help them grow their way past obstacles, a team at the John Inners Center in Norwich reports in the February 29 issue of Journal Science.

    "The key is in the fuzzy(有绒毛的) coat of hairs on the roots of plants," says professor Liam Dolan. "We have found a growth control system that enables these hairs to find their way and to become longer when their path is clear."

    Root hairs explore the soil in much the same way a person would feel their way in the dark. If they come across an obstacle, they make their way around until they can continue growing in an opening. I the meantime, the plant is held in place as the hairs grip the soil.

    The hairs are guided by a clever chemical trick. A protein(蛋白质) at the tip of the root hairs called RHD2 helps them to take calcium(钙) from the soil. Calcium makes the hairs grow, and produce more RHD2, and take more calcium.

    But when an obstacle blocks the hair's path, or the hair reaches the surface of the soil, the cycle is broken and growth starts in another direction.

    This system gives plants the flexibility to explore a complex environment and to live in even the most unpromising soils, says Dolan.

    In poor soils such as in parts of Australia and Africa, native plants have adapted by producing enormous numbers of root hairs. A better understanding of this adaptation will allow scientists to develop hairy rooted crops that can grow in unfriendly environments.

    According to Dolan, "Research in the John Inners Center is taking a breeding approach(育种方法) to increase hair length in wheat but it will be some time before new cultivars(栽培变种) are developed."

    The concept of culture has been defined many times, and although no definition has achieved universal acceptance, most of the definitions include three central ideas: that culture is passed on from generation to generation, that a culture represents a ready-made principle for living and for making day-to-day decisions, and, finally, that the components of a culture are accepted by those in the culture as good, and true, and not to be questioned. The eminent anthropologist George Murdock has listed seventy-three items that characterize every known culture, past and present.

    The list begins with Age-grading and Athletic sports, runs to Weaning and Weather Control, and includes on the way such items as Calendar, Fire making, Property Rights, and Tool making. I would submit that even the most extreme advocate of a culture of poverty viewpoint would readily acknowledge that, with respect to almost all of these items, every American, beyond the first generation immigrant, regardless of race or class, is a member of a common culture. We all share pretty much the same sports. Maybe poor kids don't know how to play polo, and rich kids don't spend time with stickball, but we all know baseball, football, and basketball. Despite some misguided efforts to raise minor dialects to the status of separate  tongues, we all, in fact, share the same language.

    There may be differences in diction and usage, but it would be ridiculous to say that all Americans don't speak English. We have the calendar, the law, and large numbers of other cultural items in common. It may well be true that on a few of the seventy-three items there are minor variations between classes, but these kinds of things are really slight variations on a common theme.

    There are other items that show variability, not in relation to class, but in relation to religion and ethnic background — funeral customs and cooking, for example. But if there is one place in America where the melting pot is a reality, it is on the kitchen stove; in the course of one month, half the readers of this sentence have probably eaten pizza, hot pastrami, and chow mein. Specific differences that might be identified as signs of separate cultural identity are relatively insignificant within the general unity of American life; they are cultural commas and semicolons in the paragraphs and pages of American life.

    The Bowler family had a very unusual experience this year. It was one of more than 400 families who applied to 1900 house, a reality TV show which took a typical family back a hundred years to see how people lived in the days before the internet, computer games and even electricity.

    The Bowler family spent three months in a London home without a telephone, computers, TV, or fast food. The bowlers wore clothes from 1900, ate only food available in England at that time, and cooked their meals on a single stove. Paul Bowler still went to work every day in a then uniform. The children changed their clothes on the way to and from school and their classmates didn't know about their unusual home life. Joyce stayed at home, cooking and cleaning like a typical housewife of the time, though everything took three times as long.

    So does Joyce think that people's lives were better in the old days?

    “I think people in the old days had just as many troubles and worries,” Joyce said. “And I don't think their life was better or worse, there were lots of things back then that I'm happy I don't have to deal with nowadays, but on the other hand life was simpler.” “We had a lot more time with our family, and it was hard being nice to each other all the time,” eleven-year-old Hilary said.

    So what did the Bowler family miss most about modern life while living in the 1900 house?

Paul, 39: “telephone and a hot shower”

Joyce, 44: “a quick cup of tea from a kettle you could just turn on”

Hilary, 11: “rock CD”

Joseph, 9: “hamburger and computer games”

    Silence is unnatural to man.He begins life with a cry and ends it in stillness.In between he does all he can to make a noise in the world,and he fears silence more than anything else.Even his conversation is an attempt to prevent a fearful silence.If he is introduced to another person,and a number of pauses occur in the conversation,he regards himself as a failure,a worthless person,and is full of envy of the emptiest-headed chatterbox（喋喋不休的人）. He knows that ninety nine percent of human conversation means no more than the buzzing of a fly,but he is anxious to join in the buzz and to prove that he is a man and not a waxwork figure（蜡塑人像）.

    The aim of conversation is not,for the most part,to communicate ideas;it is to keep up the buzzing sound.There are,it must be admitted,different qualities of buzz;there is even a buzz that is as annoying as the continuous noise made by a mosquito.But at a dinner party one would rather be a mosquito than a quiet person.Most buzzing, fortunately,is pleasant to the ear,and some of it is pleasant even to the mind.He would be a foolish man if he waited until he had a wise thought to take part in the buzzing with his neighbors.

    Those who hate to pick up the weather as a conversational opening seem to me not to know the reason why human beings wish to talk.Very few human beings join in a conversation in the hope of learning anything new.Some of them are content if they are merely allowed to go on making a noise into other people's ears,though they have nothing to tell them except that they have seen two or three new plays or that they had food in a Swiss hotel.At the end of an evening,during which they have said nothing meaningful for a long time.They just prove themselves to be successful conservationists.

    Eat your vegetables.Wash your hands.Always say“please”and“thank you”.We are full of advice for our children, but when it comes to money,we often have little to say.As a result,our children may grow up with clean hands and good manners,but without any idea how to manage their money.

    Here are some basics that will help guide them their entire lives:

    Show them the future.If your 13-year-old girl were to save $1.000,invest（投资）it at 8% and add $100 every month,by the time she's 65,she would have $980,983!

    Be careful of credit（信用）.Credit cards can help you buy necessary things and build a credit history,but they must be used responsibly,which means paying off your debt in time.Explain to your children that when you buy something using a credit card,you can easily end up paying two or three times what you would have paid if you used cash.

    Teach patience.Suppose your child wants a new bicycle that costs $150.Rather than paying the cash,give him some regular pocket money and explain that by putting aside,say,$15 each week,he will be able to buy it for himself in only ten weeks.

    Provide incentive（激励机制）.Tell your children the importance of saving."For every dollar he or she agrees to save and invest rather than spend,you agree to add another dollar to the pot,"says Cathy Pareto,expert in money planning.

    Explain your values.Values and money are deeply intertwined（纠缠在一起）,says Eilleen Gallo,co-author of The Financially Intelligent Parent.When your child demands that you buy something,explain why you really don't want to buy it.“You might say,‘I'd rather save that money for your education,'”advises Gallo.Every time you spend or don't spend money,you have a chance to share your values.

    In 2009 a new flu virus was discovered. Combining elements of the viruses that cause bird flu and swine flu, this new virus, named H1N1, spread quickly. Within weeks, public health agencies around the world feared a terrible pandemic (流行病) was under way. Some commentators warned of an outbreak on the scale of the 1918 Spanish flu. Worse, no vaccine(疫苗) was readily available. The only hope public health authorities had was to slow its spread. But to do that, they needed to know where it already was.

    In the United States, the Centers for Disease Control and Prevention (CDC) required that doctors inform them of new flu cases. Yet the picture of the pandemic that showed up was always a week or two out of date. People might feel sick for days but wait before consulting a doctor. Relaying the information back to the central organizations took time, and the CDC only figured out the numbers once a week. With a rapidly spreading disease, a two-week lag is an eternity. This delay completely blinded public health agencies at the most urgent moments.

    Few weeks before the H1N1 virus made headlines, engineers at the Internet giant Google published a paper in Nature. It got experts' attention but was overlooked. The authors explained how Google could "predict" the spread of the winter flu, not just nationally, but down to specific regions and even states. Since Google receives more than three billion search queries every day and saves them all, it had plenty of data to work with.

    Google took the 50 million most common search terms that Americans type and compared the list with CDC data on the spread of seasonal flu between 2003 and 2008. The idea was to identify areas affected by the flu virus by what people searched for on the Internet. Others had tried to do this with Internet search terms, but no one else had as much data-processing power, as Google.

    While the Googles guessed that the searches might be aimed at getting flu information—typing phrases like "medicine for cough and fever"—that wasn't the point: they didn't know, and they designed a system that didn't care. All their system did was look for correlations(相关性) between the frequency of certain search queries and the spread of the flu over time and space. In total, they processed 450 million different mathematical models in order to test the search terms, comparing their predictions against actual flu cases from the CDC in 2007 and 2008. And their software found a combination of 45 search terms that had a strong correlation between their prediction and the official figures nationwide. Like the CDC, they could tell where the flu had spread, but unlike the CDC they could tell it in near real time, not a week or two after the fact.

    Thus, when the H1N1 crisis struck in 2009, Google's system proved to be a more useful and timely indicator than government statistics with their natural reporting lags. Public health officials were armed with valuable information.

    Strikingly, Google's method is built on "big data"—the ability of society to handle information in new ways to produce useful insights or goods and services of significant value. However,   ▲  . For example, in 2012 it identified a sudden rise in flu cases, but overstated the amount, perhaps because of too much media attention about the flu. Yet what is clear is that the next time a pandemic comes around, the world will have a better tool to predict and thus prevent its spread.