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.

    The Amazing Penguin Rescue

    The summer of 2016, the ship MV Treasure sunk, creating an oil spill. Thirteen hundred tons of fuel oil were flowing right in the middle of the African Penguins' habitat. Soon the oil covered about 20,000 penguins. Without swift help, the seabirds would have no chance for survival. Volunteers were showing up by the thousands and I also took part in what was the largest animal rescue operation ever.

    A warehouse was turned into a rescue center near the habitat and hundreds of pools were built to hold about 100 oiled birds each. When walking into the center, I couldn't believe my ears. I had expected to walk into a chorus of honking and squawking(叫声). Instead, the center sounded like a library. The penguins were dead silent. My heart ached for the painful birds. Cleaning them all seemed like an impossible task. But we had to carry on like doctors in an emergency room. There was no time for doubt. Cleaning oil off a penguin wasn't easy. Even with more than 12,500 volunteers, it took a month to bathe all 20,000 birds at the center.

    While volunteers were busy bathing the oiled penguins, another crisis (危机) was developing. Oil from the spill had started moving north. Tens of thousands of penguins were in the oil's path. But we already had our hands full with 20,000 recovering birds. If any more birds were oiled, we wouldn't have enough resources to save them.

    One researcher came up with an idea: What if the penguins were temporarily moved out of harm's way? Experts decided to have a try. Volunteers rounded up the penguins and released them 500 miles away. The hope was that by the time the seabirds swam home, the oil would be gone. The plan worked! Another 20,000 penguins were saved.

    The entire penguin rescue took about three months. More than 90% of the oiled penguins were successfully returned to the wild. Looking back on the rescue, I am still amazed by the work of the volunteers. What I could hardly believe was that we accomplished an impossible task.

    It's 5:00 in the morning when the alarm(闹钟)rings in my ears. I roll out of bed and walk blindly through the dark into the bathroom. I turn on the light and put on my glasses. The house is still as I walk downstairs while my husband and three kids sleep peacefully. Usually I go for a long run, but today I choose my favorite exercise DVD, Insanity. Sweat pours down my face and into my eyes. My heart races as I force my body to finish each movement. As I near the end of the exercise, I feel extremely tired, but a smile is on my face. It's not a smile because the DVD is over, but a smile of success from pushing my body to its extreme limit.

    Some people enjoy shopping, smoking, food, work, or even chocolate. But I need exercise to get through each day. Some shake heads when they see me run through the town. Others get hurt when I refuse to try just one bite of their grandmother's chocolate cake. They raise their eyebrows, surprised by my ＂no thank you＂, or by my choice to have a salad. Over the years, I have learned it's okay to just say ＂no＂. I shouldn't feel sorry for refusing food that I don't want to eat.

    So what drives me to roll out of bed at 5:00 a.m.? What gives me the reason to just say no to ice cream? Commitment. A commitment to change my life with a way that reduces daily anxiety, increases self-confidence and energy, extends life and above all improves my body shape. This is the point where a smile appears on my face as I look at myself in the mirror or try on my favorite pair of jeans that now fit just right. It's through commitment and sweat that I can make a difference within myself inside and out.

    It was Saturday morning. I heard loud noises of moving furniture in the next room. I could almost feel the excitement of John who was soon going to get a room of his own. I remember my own feelings when I was 13. I knew how much he longed for his right to privacy (私人空间) when he was sharing a room with his younger brother, Robot. He said, “Mum, Can I please have a room of my own? I could use Jeff's. He won't mind.”

    It was true that Jeff had graduated from college and flown from the nest. But would he mind? The room was the place where I told him a thousand stories and we had a thousand talks. As close as we were, though, the time came when Jeff needed a door between us. His life was spreading into areas that had less to do with family. I no longer could-or should-know everything about him.

It turned out that getting Jeff's permission was easy. He said, “Of course, Mum, it would be selfish of me to hold on to it.” Then his voice softened, “Mum, I won't be living at home again—you know that.” Behind his glasses, his eyes were lit with all the love. There were no doors closed here—they had all opened up again.

    As John and I were cleaning the room, I fixed my eyes on Jeff's things around me and could almost touch the little boy who I knew was gone forever. I looked at the room and, in my heart, I let it go. To hold on would be, as Jeff said, selfish. Now it was time for John, shouldering through the door, his eyes bright with promise of independence, to disappear behind the door. It was time for letting go to happen again.

    At times my mom has been uncomfortable seeing these qualities in me. For example, when I was 12, I went to Puerto Rico all by myself to stay with my grandmother for the summer. My mom was extremely nervous about it. She kept telling me how things were different in Puerto Rico, to always put on sunscreen, not to wander away from my grandmother, and other warnings. She helped me pack and did not leave the airport until she saw my plane take off.

    But despite her worries, she let me go on my own. As I moved into my teens, she continued to give me space to grow and learn even when it might have been difficult for her. When I reached my senior year, I decided to move away for college. Once again I found that I differed from my peers: while many of them wanted to stay close to home, I couldn't wait to be out in the world on my own. While my mom may not have been happy at the thought of me going away, she was supportive and excited for me.

    One big thing I realized during my senior year, as my mom granted me more freedom, was that she actually believes in me and trusts me. That means a lot. Most of my life, and especially when I was little, the main person I tried to impress in my schoolwork or other things was my mother. I knew she expected nothing but the best from me. Sometimes it was hard to live up to her standards; getting a single B on my report card would make me feel bad because I knew she wanted me to have all A's.

    I know that her high standards have helped me stay focused on what's important, like education, and made me who I am. I am thankful for her support and involvement in my life. Most of all I respect her. She is the strongest woman I know and that's why I have turned out so strong and independent.

    The dangers of drowsy (昏昏欲睡) driving have been widely known. Now several companies have developed face-tracking technology that can tell when drivers become dangerously sleepy.

    Here is how it might work: A camera in your car monitors your facial expression, compares it to a database of expressions and determines if you are likely sleepy or distracted. The car then alerts you to pay attention or pull over.

    Affectiva has developed emotion recognition technology that aims to detect when people are just starting to get tired. The idea is to catch the warning signs before drowsiness really strikes. "Actually, when someone is drowsy, that is too late." Gabi, vice president of Affectiva said. "What if you can see trends in someone's face about five minutes before they become sleepy?" Affectiva's program can recognize seven different emotions and 15 facial expressions. Its standards were developed by sifting (筛选) through a database of 4 million faces from 75 counties, said Zijderveld. She suggested that carmakers could coordinate (协调) the program's facial recognition data with oral reminders, such as sound warnings, or (nonverbal) alerts, like a change of temperature and vibrations (continuous slight shaking movements).

    Eyeris is another company working in facial analytics. Modar Alaoui, the company's CEO, said that its software detects "eye openness" in addition to other facial indicators. The software can also read head position, which may indicate when someone begins to nod off.

    These technologies aren't the first attempt to fight drowsiness behind the wheel. Inventors came up with the similar device "sleeper beeper" to prevent sleep in cars back in 1983. The sleeper beeper was attached to a driver's ear and would issue a noisy warning when the driver's head nodded past a certain point. But the latest software would intervene (干涉) earlier and more effectively.