Can people change their skin color without suffering like pop king Michael Jackson? Perhaps yes. Scientists have found the gene that determines skin color.

    The gene comes in two versions, one of which is found in 99 percent of Europeans. The other is found in 93 to 100 percent of Africans, researchers at Pennsylvania State University report in the latest issue of Science.

    Scientists have changed the color of a dark-striped zebra-fish（斑马鱼） to uniform gold by inserting a version of the pigment (色素) gene into a young fish. As with humans, zebra-fish skin color is determined by pigment cells, which contain melanin (黑色素). The number, size and darkness of melanin per pigment cell determine skin color.

    It appears that, like the golden zebra-fish, light-skinned Europeans also have a mutation (变异) in the gene for melanin production. This results in less pigmented skin.

    However, Keith Cheng, leader of the research team, points out that the mutation is different in human and zebra-fish genes.

    Humans acquired dark skin in Africa about 1.5 million years ago to protect bodies from ultra-violet rays of the sun (太阳光紫外线), which can cause skin cancer.

    But when modern humans leave Africa to live in northern latitudes, they need more sunlight on their skin to produce vitamin D. So the related gene changes, according to Cheng.

    Asians have the same version of the gene as Africans, so they probably acquired their light skin through the action of some other gene that affects skin color, said Cheng.

    The new discovery could lead to medical treatments for skin cancer. It also could lead to research into ways to change skin color without damaging it like chemical treatment did on Michael Jackson.

    I've loved my mother's desk since I was just tall enough to see above the top of it as mother sat doing letters. Standing by her chair, looking at the ink bottle, pens and white paper, I decided that the act of writing must be the most wonderful thing in the world.

    Years later, during her final illness, mother kept different things for my sister and brother. "But the desk," she said again, "is for Elizabeth."

    I never saw her angry, never saw her cry. I knew she loved me; she showed it in action. But as a young girl, I wanted heart-to-heart talks between mother and daughter.

    They never happened. And a gulf opened between us. I was" too emotional". But she lived "on the surface".

    As years passed and I had my own family. I loved my mother and thanked her for our happy family. I wrote to her in careful words and asked her to let me know in any way she chose that she did forgive me.

    I posted the letter and waited for her answer, none came.

    My hope turned to disappointment, then little interest and, finally peace. It seemed that nothing happened. I couldn't be sure that the letter had even got to Mother. I only knew that I had written it, and I could stop trying to make her into someone she was not.

    Now the presence of her desk told me, as she'd never been able to, that she was pleased that writing was my chosen work. I cleaned the desk carefully and found some papers inside—a photo of my father and a one-page letter, folded and refolded many times.

    Give me an answer, my letter asks, in any way you choose. Mother, you always choose the act that speaks louder than words.

    When first entered, Vanak Restaurant does not look like much of a restaurant, but once the pleasant smells of kabob (烤肉串) hit the senses, you are incapable of calling it anything less.

    Owned by a local couple, this Persian restaurant has an inviting, homelike atmosphere that many restaurants lack.

    The space is small with only a few dining tables and nearly no decoration, but the environment is truly charming.

    Lying in a hardly noticeable street corner, the restaurant still attracts all customers, especially those experienced in the delights of Middle Eastern cooking.

    A common sight is that of old Persian men sitting in the corner talking loudly about world topics, watching news events on TV, drinking a black tea known as Persian chai, and reading local Persian newspapers all the while trying to finish off their plates piled with food.

    The variety of food at the restaurant is limited, but the amount of each dish is fairly large. Most of the meals can serve two people and are under $10, so not only is it affordable but practical as well.

    The food especially appeals to health-conscious eaters because each dish is very healthy, made with limited fat and oil and served straight off the grill (烤肉架).

    The main dish that the restaurant is popular for is its kabobs, which are different styles of grilled meat.

    One delicious and extremely healthy dish is the Joojeh Kabob, which is made of grilled chicken pieces served with either rice or bread. Another great kabob is the Chelo Kabob, a kabob consisting of grilled beef.

    Although the restaurant is small, the atmosphere and the food is delicious. It is a place that should not be overlooked.

    My mother has a dining table which sits right in the middle of her dining room. It was once buried beneath piles of papers—magazines, articles, copies of schedules for vacations she took back in the 1990s, and baby pictures of grand children who are now paying off their college loans.

    My brother Ross and I recently flew to New York to visit my mother. "Mom, why don't we go through all that stuff?" Ross said. "No. Don't touch it!" My mother said. The next afternoon, when she couldn't find a bill she needed, Ross suggested it might be put somewhere in the dining room and that we find it together. "Besides," he said, "all those papers are clearly stressing you out." However, my mother just said, "Are you boys hungry?" And then she seemed to have lost herself in deep thought.

    On our last night there, my mother walked up to us with a small pile of unopened mails, which she had collected at the western edge of the dining table, and said, "Help me go through these." "Sure," I said. When we had succeeded in separating wheat from chaff (谷壳), I asked, "Would you want to deal with another little pile of papers?"

    My mother led the way  walking into the dining room the way an animal manager might be while entering a cage with tigers in it. Ross and I came in behind her and suddenly he reached for a pile of the papers on one side of the table. "No!" my mother said sharply. "Let's start at the other end. That's where the older stuff is." Finally, we threw 95 percent of the stuff into paper shopping bags. Then I asked what she wanted us to do with them, she surprised us all by saying, "Put them in the incinerator (垃圾焚化炉)."

    When I returned home, inspired by the visit to my mother, I sorted out my own accumulated(累积的) piles of papers, sold or gave away half of my possessions, and moved into a smaller house. It seems that my life has been cheaper and easier since then. And it proves that a small change does make a big difference.

    Recently, as the British doctor Robert Winston took a train from London to Manchester, he found himself becoming steadily angry. A woman had picked up her phone and begun a loud conversation, which would last an unbelievable hour. Furious, Winston began to tweet about the woman. He took her picture and sent it to his more than 40,000 followers.

    When the train arrived at its destination, Winston rushed out. He'd had enough of the woman's rudeness. But the press were now waiting for her on the platform. And when they showed her Winston's messages, she used just one word to describe Winston's actions: rude.

    Winston's tale is something of a microcosm(缩影) of our age of increasing rudeness, fueled by social media. What can we do to fix this?

    Studies have shown that rudeness spreads quickly, almost like the common cold. Just witnessing rudeness makes it far more likely that we, in turn, will be rude later on. The only way to avoid it is to deal with it face to face. We must say, "Just stop." For Winston, that would have meant approaching the woman, telling her that her conversation was frustrating other passengers and politely asking her to speak more quietly or make the call at another time.

    The rage and injustice we feel at the rude behavior of a stranger can drive us to do odd things. In my own research, surveying 2,000 adults, I discovered that the acts of revenge people had taken ranged from the ridiculous to the disturbing. Winston did shine a spotlight on the woman's behavior — but from afar, in a way that shamed her.

    We must instead combat rudeness head on. When we see it occur in a store, we must step up and say something. If it happens to a colleague, we must point it out. We must defend strangers in the same way we'd defend our best friends. But we can do it with grace, by handling it without a trace of aggression and without being rude ourselves. Because once rude people can see their actions through the eyes of others, they are far more likely to end that strain themselves. As this tide of rudeness rises, civilization needs civility.

On one side of the room sits the cutest life-size stuffed animal(填充玩具) you've ever seen. On the other side rests a real dog—the same size, shape and even the same name as the stuffed version. You get to sit next to both of these furry friends and pet their fur. Guess which one will make your brain light up?

If you guessed the real dog, you're right. Stuffed animals, as cute and lovely as they may be, just don't effectively activate our frontal cortex(额叶皮层), the part of the brain overseeing how we think and feel, according to a new study published in the journal PLOSONE. The study found an even stronger rise in brain activity when the person petted the fur of a real dog versus a stuffed animal.

"We chose to research the frontal cortex because this brain area is involved in several executive(执行) functions, such as attention, working memory, and problem-solving. But it is also involved in social and emotional processes,"said study lead author Rahel Marti, a doctoral student in the division of clinical psychology at the University of Basel in Switzerland.

Why is this finding important? It provides additional evidence that live human-animal interaction therapy(疗法) may promote cognitive and emotional activity in the brain. Marti said,"If patients with deficits in motivation, attention, and socioemotional functioning show higher emotional involvement in activities connected to a real dog, then such activities could increase the chance of learning and of achieving treatment aims."

"This is an interesting, seriously conducted study that provides new insight into associations between human-animal interaction and regional prefrontal brain activity in healthy adults. We found that brain activity increased when the contact with a real dog or a stuffed animal became closer. This confirms previous studies relating closer contact with animals to increased brain activity,"Marti said.