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Here is an astonishing and significant fact: Mental work alone can't make us tired. It sounds absurd. But years ago, scientists tried to find out how long the human brain could labor without reaching a stage of fatigue (tiredness). To the amazement of these scientists, they discovered that blood passing through the brain, when it is active, shows no fatigue at all! If we took a drop of blood from a day laborer, we would find it full of fatigue toxins (毒素) and fatigue products. But if we took blood from the brain of an Albert Einstein, it would show no fatigue toxins at the end of the day.

So far as the brain is concerned, it can work as well and swiftly at the end of eight or even twelve hours of effort as at the beginning. The brain is totally tireless. So what makes us tired?   

Some scientists declare that most of our fatigue comes from our mental and emotional attitudes. One of England's most outstanding scientists, J.A. Hadfield, says, “The greater part of the fatigue from which we suffer is of mental origin. In fact, fatigue of purely physical origin is rare.” Dr. Brill, a famous American scientist, goes even further. He declares, “One hundred percent of the fatigue of sitting worker in good health is due to emotional problems.”

    What kinds of emotions make sitting workers tired? Joy? Satisfaction? No! A feeling of being bored, anger, anxiety, tenseness, worry, a feeling of not being appreciated—those are the emotions that tire sitting workers. Hard work by itself seldom causes fatigue. We get tired because our emotions produce nervousness in the body.

    Did you know that sixty percent of your body weight is water? However, a loss of only two percent of this water through dehydration (脱水) during exercise can significantly affect your performance. The more you sweat, the more your exercise performance declines, unless you drink enough to replace your loss of fluids (液体).

    When you lose too much water, you can overheat quite easily, especially in a warm environment. But this is not the only problem you may face. Dehydration leads to your heart pumping much faster, which means exercise becomes more difficult and requires more effort. Despite these problems, however, many of us simply do not take enough fluids in when we head for the gym or set out on a run.

    So why is this? How do we manage to lose so much water without simply drinking more to replace it? Well, it's easier than you think. When we are at rest, we quickly become aware that we are thirsty and will put that right by having a drink. When we exercise, on the other hand, our thirst mechanism (结构) does not work as effectively, so we don't notice early enough that we are actually thirsty. In fact, we only start to fed thirsty when we have already lost around two percent of our body weight.

    Another problem is that, the more dehydration we become during exercise, the more difficult it is to prevent further dehydration-because our stomachs become intolerant (不能容忍的) to fluids and we do not absorb water properly, just when we need it most.

    The key thing about fluids and exercise is to manage your intake properly-regular small amounts are preferable, and some should be drunk before the period of exercise begins. You also need to match your intake to the sort of exercise you are doing. For example, for one hour of exercise, such as taking part in a 10 km run, you need to drink about two extra litres of water. For longer periods of exercise, sports drinks are recommended.

    In a class this past December,after I wrote some directions on the board for students about their final examination,one young woman quickly took a picture of the board using her smart phone.When I looked in her direction,she apologized:"Sorry.Was it wrong to take a picture?"

    “I can't read my own handwriting,”the young woman explained."It's best if I take a picture of your writing so I can understand the notes."

    That remark started a class-wide conversation about taking a picture instead of taking notes.For those in the photo-taking camp,motivations extended beyond their inability to comprehend their own handwriting.Some took pictures of notes because they knew their phone was a safe place to store material.They might lose paper,but they wouldn't lose their phones.Some took photos because they wanted to record exactly the manner in which I had noted information on the board.Others told me that during class they liked to listen to the discussion attentively.

    Yet the use of cameras as note takers,though it may be convenient,does raise significant questions for the classroom.Is a picture an effective replacement for the process of note-taking?

    Instructors encourage students to take notes because the act of doing so is more than merely recording necessary information—it helps prepare the way for understanding.Encouraging students to take notes may be an old-fashioned instructional method,but that a method has a long history doesn't mean it's out of date.Writing things down engages a student's brain in listening,visual,and kinesthetic learning—a view supported by a longstanding research.The act of writing down information enables a person to begin committing it to memory,and to process and combine it,establishing the building blocks of learning new concepts.

    Taking a picture does indeed record the information,but it deletes some of the necessary mental engagement that taking notes employs.So can the two be equally effective?

    I'm not sure how to measure the effectiveness of either method.For now,I allow students to take notes however they see fit—handwritten or photographed—because I figure that some notes,no matter the method of note-taking, are better than none.

    Earlier this month, blogger Lisa Henderson announced that she and her husband John had decided not to have Christmas. The family, who lives in Utah, will still put up decorations, but presents from Santa are a no-go this year.

    “John and I feel like we are fighting a very hard uphill battle with our kids when it comes to their rights,” Henderson wrote on her blog. “It is one of the biggest struggles as a parent these days in middle class America. Our kids have been acting so ungrateful lately. ... John said, “We shouldn't just celebrate Christmas. And, so that's what we did.”

    Instead, the Hendersons are putting the money they would have spent on gifts toward service projects in order to teach their three sons the “pleasure of giving.” The children will still receive gifts from grandparents and other family members, but this year, she said, their letters to Santa will be asking him to find someone who needs presents more than they do.

    In an interview with ABC News, 11-year-old Caleb Henderson admitted that he and his brothers had been behaving badly. “We would hit each other. We were fighting and crying,” he admitted, and Lisa said that when she broke the news to her sons, they cried pretty hard.

    But so far, Henderson told Fox News last week, the family is having a sudden turning this into a different kind of gift. They have already held a clothing drive and sent boxes of clothes and candy to a village in the Philippines that was hit hard last year by Typhoon Haiyan.

    “The children were excited and kept wanting to give more and more,” she reported on her blog.

    Many readers responded positively to Henderson's post. Some sharing their own stories of limiting Christmas in order to teach their children to be charitable(仁慈的) or grateful. “As parents you're giving your kids something so much more special than a bunch of gifts on Christmas,” one wrote.

    But Henderson received negative follow-ups as well on her blog. Responding to critics, she updated her blog with a statement that reads, in part:

I just wanted to explain a couple of things. First, my kids are in no way hurt for things.... They have reacted by making gifts for each other and packing them into each other's stockings stealthily(偷偷地). They are learning exactly what we wanted them to learn, because they are not moving around feeling sorry for themselves. They are thinking of others.

    The second thing I wanted to explain is why I wrote this post. Some people seem to think I wrote this for attention. Ummm, the attention you get from posts like this is not good and actually extremely difficult to deal with.... The reason I wrote this post is I want to empower parents to feel like it's okay to take a stand. ... I wanted to share what we are doing, so any parents that feel they are struggling with the same issues in their home can see what others are doing and get ideas for their family. My intention is to help support other parents and to raise amazing kids.

    With the rapid development of China's economy, more and more foreigners begin to learn Chinese because they are beginning to realize the importance and growing influence of China. Pupils in Warwickshire will soon be learning Mandarin after new links were forged(建立联系) with a region in China.

    Head teachers from the county spent a week in Shenzhen in South-east China, making links with schools and touring different education establishments.

    Schools that took part are now looking to introduce Mandarin lessons. Pupils from schools in Warwickshire and Shenzhen are starting to write and e-mail each other and plans are being made to share lessons over the Internet.

The trip was arranged by Warwickshire County Council and funded by the British Council as the first stage of development of a range of ties with the economically booming city.

    International development officer Judith Young said: “We are entering an exciting period of school relation between Warwickshire and Shenzhen. There is a real appetite for sharing ideas among the Chinese. We were able to see the differences and similarities between the education systems and there are many areas in which our schools, teachers and pupils will be able to benefit from a different cultural perspective(观点) and links with a country that is becoming very important on the world stage.

    Throughout the high profile(引人注目) visit led by our county education officer, Eric Wood, our group was made to feel very welcome and attracted a great deal of interest. Our visit to a primary school was featured as the main news item on television that night. A mark of how highly the visit was valued is that plans are being made for a return visit to Warwickshire of civic leaders, senior education officials and school principals.”

    This year's flu season is pretty scary. To try to minimize the effects, public officials are still urging anyone who hasn't yet gotten their flu shot to get one as soon as possible. However, even if every single person got a shot in the arm, the vaccine(疫苗)—with its excellent 36 percent effectiveness—would not prevent everyone from getting infected with the annoying virus. Knowledge is power, so here's what goes on in your body when you come down with the flu.

    The influenza virus primarily attacks your nose, throat, and the tubes that lead to your lungs. But the flu is so much more than that. Your muscles ache, your head hurts, and your appetite goes down, among other things. To our surprise, almost all of these symptoms have less to do with the virus itself than with your immune(免疫的)response to them. Unfortunately, the very defense you have in place to get rid of the flu is the reason you feel so painful when you recover.

    The virus usually enters through your mouth, typically by way of your hands. But it takes a few days for symptoms to set in. While this process might cause some harm to your nose and throat, it's nothing major, and nothing like the symptoms that typically accompany a bad or even mild case of the flu.

    The real fun starts when your immune system begins to fight. Your immune system comes in two parts: the innate system and the adaptive. The innate immune system is essentially an all-purpose tool. As soon as your body senses the presence of any injury or invader (入侵者), the innate immune system launches into action by producing tiny proteins called cytokines and chemokines. The cytokines reproduce almost immediately and start to attack the virus. This increase in immune cells creates an serious inflammation(炎症) throughout the body. But the worst is still to come. Meanwhile, the chemokines work with the adaptive immune system to help create T cells. These cells are a special type of white blood cell that works in a much more specific way: They find the influenza virus, identify what's special about it, and create something unique on their surface that finds and destroys similar invaders.