Like many other people, I love my smart phone, which keeps me connected with the larger world that can go anywhere with me. I also love my laptop，because it holds all of my writing and thoughts. In spite of this love of technology, I know that there are times when I need to move away from these devices and truly communicate with others.

    On occasion, I teach a course called History Matters for a group of higher education managers. My goals for the class include a full discussion of historical themes and ideas. Because I want students to thoroughly study the materials and exchange their ideas with each other in the classroom, I have a rule —no laptop, iPads, phones, etc. When students were told my rule in advance of the class, some of them were not happy.

Most students assume that my reasons for this rule include unpleasant experiences in the past with students misusing technology. There's a bit of truth to that. Some students assume that I am anti-technology. There's no truth in that at all. I love technology and try to keep up with it, so I can relate to my students.

    The real reason why I ask students to leave technology at the door is that I think there are very few places in which we can have deep conversions and truly engage complex ideas. Interruptions by technology often break concentration and allow for too much dependence on outside information for ideas. I want students to dig deep within themselves for inspiration and ideas. I want them to push each other to think differently and make connections between the course materials and the class discussion.

I've been teaching my history class in this way for many years and the evaluations reflect student satisfaction with the environment that I create. Students realize that with deep conversation and challenge, they learn at a level that helps them keep the course materials beyond the classroom.

I'm not saying that I won't ever change my mind about technology use in my history class, but until I hear a really good reason for the change, I'm sticking to my plan. A few hours of technology-free dialogue is just too sweet to give up.

    The Board Meeting had come to an end. Bob started to stand up and pushed the table, spilling his coffee over his notes. “How embarrassing! I am getting so clumsy in my old age.”

    Everyone had a good laugh, and soon we were all telling stories of our most embarrassing moments. It came around to Frank who sat quietly listening to the others.

    Frank began,“My Dad was a fisherman. He worked hard and would stay out until he caught enough to feed the family. Not just enough for our family, but also for his Mom and Dad and the other kids that were still at home.”

    Frank's voice dropped a bit. “When the weather was bad he would drive me to school. He would pull right up in front, and it seemed like everybody would be standing around and watching. Then he would lean over and give me a big kiss on the cheek and tell me to be a good boy. It was so embarrassing for me. Here I was twelve years old, and my Dad would lean over and kiss me good-bye!”

    He paused and then went on, “I remember the day I thought I was too old for a good-bye kiss. When we got to the school, he had his usual big smile. He started to lean toward me, but I put my hand up and said, 'No, Dad.' It was the first time I had ever talked to him that way, and he had this surprised look on his face. I said, 'Dad, I'm too old for a good-bye kiss. I'm too old for any kind of kiss.' My Dad looked at me for the longest time, and his eyes started to tear. I had never seen him cry. He turned. 'You're right,' he said. 'You are a big boy ... a man. I won't kiss you anymore.'”

    For the moment, the tears began to well up in Frank's eyes. “It wasn't long after that when my Dad went to sea and never came back.”

    I looked at Frank and saw that tears were running down his cheeks. Frank spoke again.“Guys, you don't know what I would give to have my dad give me just one more kiss on the cheek.”

    One of the most important aspects of an image is color. People are very sensitive to color, and different colors have different on people.

    In general, red is an exciting color, which creates an image of action, energy danger. Red is also the most frequently used color in flags. Eighty percent of the world's flags contain red. A study in Germany showed that football teams wearing red are more successful. Blue is a very calm color. Business executives usually wear dark blue suits. Blue is also a peaceful color. The flag of the United Nations is light blue. Yellow is associated with openness and freedom. Green is a very relaxing color. Surgeons nowadays wear green, because it's less tiring than white. Black creates an image of power and authority. It can also be a very threatening color. Gangsters and vampires often wear black, white is a pure and strong color. This is one reason why doctors wear white coats. We trust them more. Grey is a very anonymouscolor. People wearing grey don't want other people to notice them. Brown is the opposite of black. It's warm and friendly, while black is threatening

    Plastic sludge(污泥)and garbage is a disaster for the world's oceans. A film crew traveled the globe to document the rubbish. And Julie Andersen of the Plastic Oceans Foundation says what we see is just the tip of the problem. “Half of the waste actually sinks to the bottom, and that remains on the surface actually breaks down. ”

    The filmmakers found rubbish in ocean gyres, the circulating currents that trap large concentrations of pollution in the Atlantic, Indian, and Pacifc Oceans, home of what some have plastic. What we found was a plastic smog that spread throughout all the water. And in some parts of the oceans, scientists have found more plastic than plant. ”

    The pieces of the plastic garbage infect the food chain, sometimes visibly, and more so at the microscopic level, where the plastic particles interact with other pollutants. “There are heavy metals, medicines, industrial waste in the sea, while it acts like magnets(磁铁). These poisonous substances absorb on the plastic, and then when seafood absorbs the plastics, those poisonous substances enter the fatty tissues. ”To be consumed by other sea life and by people at last.

    China, Indonesia, the Philippines, Thailand and Vietnam are the worst plastic polluters. The United States, although a leader in recycling, is one of the world's 20 since it produces and consumes so much plastic. There are efforts around the world to address the problem, including at this newly opened recycling center in Lebanon(黎巴嫩). But Andersen says there is more that people can do. “Cut back on single-use plastics, straws, plastic cups, plastic water bottles, plastic bags and find alternatives like reusable materials.” She says healthy oceans are essential to our survival.

Rich as a King

    William 1, who conquered England some 930 years ago, had wealth, power and an army. Yet although William was very rich by the standard of his time, he had nothing like a flush toilet (抽水马桶), paper towels, or riding lawn mower (除草机). How did he get by?

    History books are filled with wealthy people who were poor compared to me. I have storm windows, Croesus did not. Entire nations trembled before Alexander the Great, but he couldn't buy cat food. Czar Nicholas lacked an electric saw.

    Given how much better off I am than so many famous dead people, you'd think I'd be content. The trouble is that, like most people, I compare my wealth with that of living person: neighbors, school classmates, famous TV people. The greed I feel toward my friend Howard's new kitchen is not reduced by the fact that no kings ever had a refrigerator with glass doors,

    There is really no rising or falling standard of living. Over the centuries people simply find different things to feel sad about. You'd think that simply not having disease would put us in a good mood, but no we want a hot bath too.

    Of course, one way to achieve happiness would be to realize that even by today's standards the things I own are pretty nice. My house is smaller than the houses of many investment bankers, but even so it has a lot more rooms than my wife and I can keep clean.

    Besides, to people looking back at our era from a century or two in the future, these bankers' fancy counter tops and my awn worn Formica will seem equally shabby, I can't keep up with my neighbors right now. But just wait.

    Do you often feel like you want to wash your hands again and again? Or do you ever have the urge to line up the items on your desk? These all may be symptoms of obsessive-compulsive disorder (强迫症), or OCD, which affects about 2 percent of the world's population.

    Those who suffer from OCD have difficulty finding successful treatment because doctors don't clearly understand its causes. But now, a new study has given hope for a future cure.

    For the study, which was published in the journal Nature in October, researchers observed humans, dogs and mice. They discovered four genes that may be responsible for obsessive-compulsive behaviors in humans.

    But why observe dogs and mice to learn about humans?

    "Dogs, it turns out, are surprisingly similar to people," study author and geneticist Elinor Karlsson, of the Broad Institute of MIT and Harvard University, US, told NPR. "They're chasing their own tail or chasing shadows like normal, but they're doing it for hours."

    In the study, researchers made a list of about 600 genes in mice, dogs and humans that they thought might cause OCD, reported NPR. They then compared those genes in two large groups of people – those who don't have OCD and those who do. In the end, they identified just four genes with mutations (突变) in the OCD group. The genes are active in a neurological pathway (神经通路) in the brain, which is believed to help control actions. But the mutations could block the neurological pathway.

    For example, for people without OCD, when they finish washing their hands, a signal will come, telling them to stop. But for people with OCD, the neurological pathway is blocked, so the message isn't getting through. As a result, the person will continue to wash their hands.

    "OCD and anxiety are kind of like learning disorders," Marcos Grados, an OCD researcher at Johns Hopkins University School of Medicine, told NPR. "Often with OCD, people have a fear of germs (细菌). You can't touch tables or door knobs (把手) and every time it's the same sensation (感觉). You didn't learn that the last time you touched a door knob, nothing happened. It's like touching it for the first time ever."

    However, that doesn't mean people who have these genetic mutations will always have obsessive-compulsive behaviors, the researchers said. That's because the disorder also relies on other things, such as one's environment.

    According to reports, various existing treatment methods have low success rates in patients. But now that we know where OCD comes from, let's hope we will soon find an effective way to treat it.