In 1999, twelve percent of public elementary schools in the United States required students to wear uniforms. Just three years later, the amount was almost double that.

    A study of six big-city Ohio public schools showed students who were required to wear uniforms had improved graduation, behavior and attendance rates. Academic performance was unchanged.

    Some high schools in Texas have also joined in the movement. Yet studies find mixed results from requiring uniforms. And some schools have turned away from such policies.

    Supporters believe dressing the same creates a better learning environment and safer schools. The school district in Long Beach, California, was the first in the country to require uniforms in all elementary and middle schools. The example helped build national interest in uniforms as a way to deal with school violence and improve learning.

    Findings in Long Beach suggested that the policy resulted in fewer behavior problems and better attendance. But researcher Viktoria, who has looked at those findings, says they were based only on opinions about the effects of uniforms.

    She says other steps taken at the same time to improve schools in Long Beach and statewide could have influenced the findings. The district (the area marked by government) increased punishments for misbehavior. And California passed a law to reduce class sizes.

    In Florida, for example, researcher Sharon found that uniforms seemed to improve behavior and reduce violence. In Texas, Eloise found fewer discipline problems among students required to wear uniforms, but no effect on attendance.

    Sociologist David has studied school uniform policies since1998.He collected the reports in the book. In his own study, he found that reading and mathematics performance dropped after a school in Pennsylvania（宾夕法尼亚州）required uniforms.

    Political and community pressures may persuade schools to go to uniforms to improve learning. But David and others believe there is not enough evidence of a direct relationship. In fact, he says requiring uniforms may even increase discipline problems.

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    Being physically active three times a week reduces the odds of being depressed by about 16%, according to new UCL research carried out as part of the Public Health Research Centre.

    The study, published in JAMA Psychiatry, found a two-way relationship between depression and physical activity. People who increased their weekly activity were reported to have fewer depressive symptoms but those with more depressive symptoms were less active, particularly at younger ages.

    Researchers followed 11,135 people born in 1958 up until the age of 50, recording depressive symptoms and levels of physical activity at regular intervals in adulthood. They found that each additional activity period per week reduced odds of depression by 6%. In England 19% of men and 26% of women are currently classed as "inactive", and this study suggests that activity could significantly improve their mental as well as physical health.

    "Assuming the association is causal, physical activity has a protective effect against depression. If an adult between his twenties and forties who isn't physically active became active 3 times per week, he would reduce his risks of depression by about 16%," said Dr Snehal of the UCL Institute of Child Health, lead author of the study.

    Professor Mark，Director of the Public Health Research Centre, said: "Many people are already aware of the benefits of physical activity on their general health, but now we are seeing more evidence that suggests it also has a positive effect on a person's mental well-being. The latest research highlights just how important it is to ensure that people are working and living in environments that allow them to be both physically active and mentally healthy."

    Anyone who cares about what schools and colleges teach and how their students learn will be interested in the memoir(回忆录)of Ralph W. Tyler, who is one of the most famous men in American education.

    Born in Chicago in 1902, brought up and schooled in Nebraska, the 19-year-old college graduate Ralph Tyler became hooked on teaching while teaching as a science teacher in South Dakota and changed his major from medicine to education.

    Graduate work at the University of Chicago found him connected with honorable educators Charles Judd and W. W. Charters, whose ideas of teaching and testing had an effect on his later work. In 1927, he became a teacher of Ohio State University where he further developed a new method of testing.

    Tyler became well-known nationally in 1938, when he carried his work with the Eight-Year Study from Ohio State University to the University of Chicago at the invitation of Robert Hutchins.

    Tyler was the first director of the Center for Advanced Study in the Behavioral Sciences at Stanford, a position he held for fourteen years. There, he firmly believed that researchers should be free to seek an independent(独立的)spirit in their work.

    Although Tyler officially retired in 1967, he never actually retired. He served on a long list of educational organizations in the United States and abroad. Even in his 80s he traveled across the country to advise teachers and management people on how to set objectives(目标)that develop the best teaching and learning within their schools.

    Over the years Lisa urged her sister Helen to prepare for her old age. Now they passed sixty. Lisa had a big house, Helen had the clothes on her back.

    Lisa had hated being a child and couldn't wait to grow up and buy herself everything. What Helen wanted was to go outside and play.

    When anyone would hire her, Lisa put herself to work. She never touched a penny of her money though her young mouth watered for ice cream and candy. When the dimes (一角硬币) added up to dollars， she lost her taste for sweets. And her bankbook became her most precious possession.

    Helen had a boyfriend Harry whose only ambition was to play a horn. That Helen married Harry straight out of high school was not surprising. Two or three times Lisa was halfway persuaded, but to give up a job that paid well for a homemaking job that paid nothing was a risk she was unable to take.

    Helen's married life was nothing for Lisa to envy. She and Harry played in second-rate bands. But Lisa had a big house because her boss offered her his first house at a price so low that it would be like losing money to refuse.

    Harry died abroad, in a third-rate hotel, with Helen crying as hard as if he had left her a fortune. He had left her nothing but his horn. Lisa knew she would have to bring her home.

    At dinner, Helen began to tell stories. They were rich with places and people, most of them lowly, all of them magnificent. Her face showed the joys and sorrows.

    Then Lisa knew why Helen didn't mention the shining room. Tonight Helen saw only what she had come seeking, a place in her sister's home and heart.

    She said, “That's enough about me. How have the years used you?” “I didn't use them,” said Lisa regretfully. “I saved for them but forgot to enjoy them. Now it's too near the end to try. ”Helen said, “Don't count the years that are left to us. At our time of life it's the days that count. You've too much catching up to do to waste a minute of a waking hour feeling sorry for yourself.” Lisa smiled.

    Why do we dream? It's a question researchers have been studying for years. Now new research suggests that some dreams may result from the brain's effort to keep learning, even as we sleep.

In a study in Boston,100 volunteers were trained for an hour on a maze(迷宫). They tried to find their way through the difficult puzzle as quickly as possible. Then half of the volunteers were allowed to sleep for 90 minutes. The other half stayed awake, reading or relaxing. The ones who slept were asked to describe their dreams when they woke up.

    After the rest, the volunteers were asked again to solve the maze. Those who hadn't slept showed no improvement or did even worse after the break. Sleepers who didn't report any maze­related dreams did better but showed only a little improvement. However, four nap­takers who reported dreaming about the maze showed a surprising improvement. They scored 10 times higher after sleeping and dreaming about the maze.

    Even though the number of dreamers was small, the researchers noted that the gap in learning between the dreamers and non­dreamers was so wide that the finding was significant(有意义的).

The dreamers had all performed poorly on the test before dreaming about it. That suggests that struggling with a task might be the trigger that leads the sleeping brain to focus on it and work on how to deal with it.

    "It's almost as if your brain is going through everything that happened today," Dr Stickgold, a scientist at Harvard Medical School, said. "The things you're obsessed(迷住) with are the ones that your brain forces you to continue to do with."

Friends play an important part in our lives, and although we may take friendship for granted, we often don't clearly understand how to make friends. While we get on well with a number of people, we are usually friends with only a very few — for example, the average among students is about 6 per person. In all the cases of friendly relationships, two people like one another and enjoy being together, but beyond that, the degree of intimacy between them and the reasons for their shared interests vary greatly. As we get to know people, we take into account things like age, race, economic condition, social position, and intelligence. Although these factors are not of great importance, it is more difficult to get on with people when there is a marked difference in age and background.

Some friendly relationships can be kept on argument and discussion, but it is usual for close friends to have similar ideas and beliefs, the same opinions and interests — they often talk about "being on the same wavelength". It generally takes time to reach this point. And the more intimately involved people become, the more they depend on one another. People who want to be friends have to learn to put up with annoying habits and to stand differences.

In contrast with marriage, there are no friendship ceremonies to strengthen the association between two people. But the supporting and understanding of each other that results from shared experiences and emotions does seem to create a powerful bond, which can overcome differences in background, and break down barriers of age, class or race.