As the new semester begins, millions of college students across the country are trying hard to remember how best to write a paper or, more likely, how best to delay that paper.

    Procrastination is the thief of time and a lot of students suffer form it. They can spend whole days in the library doing nothing but staring into space, eating snacks, surfing the Internet, watching videos and looking at other students sitting around them, who, most likely are doing nothing either.

    Paralyzed (使失去活力) by their habit to procrastinate, they write micro blogs about their fears, asking their online friends if they sometimes have the same issue. But this does nothing to break the spell (魔咒).

    According to a recent report, 95 percent of us procrastinate at some point and 20 percent of the world's population are always procrastinating. The figures are disappointing. Procrastinators are less wealthy, less healthy and less happy than those who don't delay. Procrastinators like to find excuses to justify their behavior, but BBC columnist Rowan Pelling says they are all wrong.

    Many procrastinators tell themselves they are perfectionists who work best under pressure. Pelling says this is non sense, as work done at the last minute is more likely to have mistakes than work done on time. The behavior of procrastinators often makes them feel ashamed, inconveniences others and annoys loved ones.

    Pelling also points out that procrastination feels particularly delinquent（过失的） in a society that thinks of speedy action as admirable, and, at times, even as a moral good.

    Fortunately, social scientists have thrown their weight behind efforts to understand this behavioral mistake and offer strategies to control it. Piers Steel, a Canadian social scientist and author of The Procrastination Equation, believes human is “designed” to procrastinate. Nevertheless, he suggests a couple of good ways to get through the task at hand.

    Today, we know that the role of vitamins and minerals goes way beyond the prevention of deficiency diseases (维生素缺乏症) to actually preventing cancer and heart disease, the most fearsome killers of our time. With this knowledge has come the widespread call for nutritional supplementation (营养补充) — and a confusing group of vitamin, mineral, and supplements lining the supermarket shelves.

    Far from contributing to better health, however, nutritional supplements threaten to turn a scientific breakthrough into a nutritional disaster.

    Promoters of vitamins and minerals — especially vitamins A, C, and E— would have consumers believe that the little vitamin pill in the bottle is all they need for good health. Take your vitamins in the morning, and you're covered. It's okay to eat fast foods for the rest of the day or skip meals to achieve today's fashionably skinny look. But vitamins and minerals are only one part of the nutritional puzzle. A diet rich in fiber (纤维) and balanced in carbohydrates and protein is essential for good health. You can't get these things from a nutritional supplement. The focus on vitamin and mineral supplements may actually be robbing us of the full nutrition we seek.

    And no supplement can compare to the quality of nutrition found in natural sources. For example, our bodies turn carotenes (胡萝卜素) from plant foods into vitamin A. Many supplements contain a single carotene, but natural sources are rich in many different carotenes. Many supplements contain a form of vitamin E that is made from chemicals, when natural vitamin E is more readily absorbed and used by the body. And science is still discovering the wealth of nutrients in foods.

    You'd be hard-pressed to find a supplement as nutritionally comprehensive and powerful as a balanced diet. Even if you could, you'd pay much more than if you got the same nutritional value from natural sources.

    But perhaps the greatest danger presented by nutritional supplements comes from the very real risks presented by self-medication. Anyone can walk into the market and buy as many different supplements as desired. The reported benefits of high dosages of certain nutrients have led some people to believe that the more the better. Many take several vitamin and mineral supplements without regard to possible consequences.

    Surprising new research suggests that vitamin C pills may speed up hardening of the arteries, the underlying cause of heart attacks. Researchers said their findings support the recommendations of health organizations, which urge people to avoid high doses of supplements and to get their nutrients from food instead.

    As appealing as they're made to sound, nutritional supplements are danger in disguise. If you're looking for good health, don't look on the supplement shelves of your supermarket. Look in the produce section instead.

    As sea levels climb, even Washington, D. C. could see more frequent and widespread flooding at high tide.

    Strong storms and high winds sometimes bring floods to coastal areas. But cities and towns along the US East Coast are flooding even in calm and sunny weather. Among them is Maryland's capital Annapolis. Tourists there must sometimes walk through water flooding downtown streets surrounding the habor. Sometimes water covers roads in Atlantic City, N. J. Even the yards and basements of coastal homes near New York City sometimes flood.

All are suffering from this trend—normal high tides surpass (超过) a rising sea level.

    Sea levels have climbed, on average, about 20 centimeters (8 inches) over the past 135 years. And a sharp increase in tide flooding is one of the more visible impacts affecting many coastal areas, notes William Sweet, an oceanographer.

    Sweet and his co-workers recently analyzed data from 45 tide gauges (计量表) along the US coasts. These tools record the changing heights of tides as they rise and fall. From these data, Sweet's team calculated the number of : “troublesome floods” in various coastal cities. These floods, Sweet explains, typically occur when water level is about 30 centimeters (1foot) above the historic level of the highest tides. In June 2014, the team reported finding a growing rise in these flooding events.

    In Charleston, S.C. from 1957 to 1963, the city experienced troublesome floods an average of 4. 6 days per year. Bur from 2007 to 2013, the occurring rate of troublesome floods jumped five times. Annapolis city was even more serious. From1957 to 1963，troublesome floods were roughly 3. 8 days per year. From 2007 to 2013, the average was 10 times higher- 39. 3days a year.

    “Over the next few decades, climate change probably drives sea levels even higher,” Sweet says. “So today's flooding problems promise to become only more widespread and frequent.”

    Artificial intelligence keeps defeating human, it is making countless victories against human in different fields of life and trying to push human to the corner.

    Google's DeepMind has defeated the world's number one player Ke Jie. Human brain somehow has been replaced by a machine and scientists are working very hard on developing a human brain by implanting a chip and connecting it to the thick neuron that connects the two hemispheres of the brain. Well, who doesn't want to get his brain upgraded to be as smart as the brain of Albert Einstein or Charles Darwin?

    Humans will probably one day invent a brain that can be implanted in the human skull and reprogram all the human thoughts, but this invention doesn't seems to be happening in the foreseeable future since human brain took millions of years to evolve. Some scientists believe that human will defeat death in the next twenty hundred years but they can't really predict how long it's going to take to develop a human brain that can completely replace the natural brain.

    Despite of this accomplishment in the field of artificial intelligence, it couldn't crease people from believing that science can't stand alone. For instance, AI can imitate human brain and most of the time outperforms it, but there are still a lot of hidden secrets. AI outsmarted Ke Jie has consciousness unlike the AI, Ke Jie felt sad when he was defeated and buried his face in his hands but the AI didn't feel happy and celebrate his victory.

    The computer of 1960 is the same as the computer of 2017 in terms of consciousness, there is no signs so far telling us that there is an algorithm(运算)that can make a conscious computer and decipher (译解) its feelings. We can predict what the future will look like according to the past, especially from scientific point of view but the development of human brain seems unpredictable and unknown.

    By trying to tickle(挠痒痒) rats and recording how their nerve cells respond, Shimpei Ishiyama and his adviser are discovering a mystery that has puzzled thinkers since Aristotle expected that humans, given their thin skin and unique ability to laugh, were the only ticklish animals.

    It turns out that Aristotle was wrong. In their study published on Thursday, Ishiyama and his adviser Michael Brecht found that rats squeaked and jumped with pleasure when tickled on their backs and bellies. These signs of joy changed according to their moods. And for the first time, they discovered a special group of nerve cells. These nerve cells made this feeling so powerful that it causes an individual being tickled to lose control.

    To make sure that he had indeed found a place in the brain where tickling was processed, Ishiyama then stimulated that area with electrical currents. The rats began to jump like rabbits and sing like birds.

    “It's truly ground-breaking,” said Jeffrey Burgdorf, a neuroscientist at Northwestern University who reviewed the paper. “It takes the study of emotion to a new level.”

    Burgdorf has played a central role in our understanding of animal tickling. He was part of a team that first noticed, in the late 1990s, that rats made special noises when they were experiencing social pleasure. Others had already noted that rats repeatedly made short and high sounds during meals. But the lab where Burgdorf worked noticed that they emitted similar sounds while playing. And so one day, the senior scientist in the lab said, “Let's go and tickle some rats.” They quickly found that those cries of pleasure doubled.

    “The authors have been very adventurous,” said Daniel O'Connor, a neuroscientist at Johns Hopkins University who studies touch. To him, that finding was very surprising.

    “Why does the world literally feel different when you are stressed out?” he said. “This is the first step towards answering that question. It gives us a way to approach it with experimental rigor(严谨).”

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