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.

    Researchers at Brigham found about one in five teenagers now have some degree of hearing damage. The researchers did not say why hearing loss has risen, but other experts have strong suspicions. One likely culprit, they say, is MP3 players.

    An MP3 player can be dangerous to hearing when its decibel level is turned up too high. High-decibel sounds can damage nerve endings, called hair cells. If a sound is loud enough, the damage can be permanent. A loud sound can shake the membrane (薄膜) on which the hair cells sit- “like an earthquake”. That shake can break or even uproot hair cells. When that happens, the hair cells are finished. Human ears cannot regrow hair cells. Therefore, when listening to an MP3 player, set a volume limit and avoid exposure to loud sounds.

    On the other hand, the loudness of today's music may not be totally under your control. Music companies have been purposely turning up the volume. It's a trend called the fight for loudness.

    Play a CD from the 1990s. Then play a newly released tune. Don't touch the volume control. You'll probably notice that the new CD sounds louder than the old one. Why? Sound engineers who create CDs are using dynamic range compression (压缩), a technology that makes the quiet parts of a song louder and the loud parts quieter. The overall effect of compression is a louder recording.

    Many musicians and sound engineers aren't pleased. They say that compression is driving down the quality of today, s music, making it sound flat and blaring. Gray Hobish, a sound engineer, explains that music should be a combination of loudness and softness. But music companies want to make music louder so it will stand out. That's important in the competition among recording companies.

    What about listeners? Many teenagers listen to music on the go in noisy places and through headphones, all of which reduce sound quality. So young listeners may not notice the poorer quality of modem recordings. “To their ears,” says Hobish, “the music sounds fine. And they are not aware of the hidden threat of the music they are enjoying.”

    Over the past few years I've had an uncomfortable sense that someone, or something, has been making changes to my brain. I'm not thinking the way I used to think. I can feel it most strongly when I'm reading. Involving myself in a book or a lengthy article used to be easy. That's rarely the case any more.

    I think I know what's going on. For over a decade, I've been spending lots of time online. The Web has been a godsend to me as a writer. Research that once required days in the rooms of libraries can now be done in minutes by a few Google searches. Even when I'm not working, I'm scanning headlines or just tripping from link to link.

The Net is becoming a universal medium where information flows through my eyes and ears and into mind. The perfect recall of silicon memory (硅制存储器) can be a blessing to thinking. But that comes at a price. As the media theorist Marshall Mcluhan pointed out, media are not just passive channels of information. They supply the stuff of thought, but they also shape the process of thought. And what the Net seems to be doing is weakening my ability for concentration. Once I was a driver in the sea of words. Now I zip along the surface like a flying swallow.

I'm not the only one. When I mention my troubles with reading to acquaintances, Bruce Friedman, a blogger, also has described how the Internet has changed his mental habits. His thinking has taken on a "staccato (破碎)" quality. "I can't read War and Peace any more" he admitted, "I've lost the ability to do that."

A recently published study suggests that when reading online, we tend to become "more decoders (解码器) of information". We are not only what we read; we are how we read.

Planning Your Family Trip

    Plan ahead to make your family trip run smoothly. Family vacations are cherished memories. Keeping children entertained on the road or during a flight, however, can be challenging. The best way to cut down on anxiety? Plan ahead.

    Avoid giving children snacks that contain sugar and caffeine. Sweet treats keep them happy and quiet for five minutes, as it fills them with unusable energy that will turn into crankiness (偏执) when the sugar wears off. Bring fun, small snacks like flavored baked chips, apple sauce, raisins, and granola bars—and top it off with a little protein like cheese sticks to keep the blood sugar levels nice and steady.

    Bring plenty of plastic or paper bags. This is the perfect time to put those spare bags around the house to use. Store them in your purse or pocket, as well as in the car. This is a quick solution for garbage, diaper wrapping or motion sickness.

    Avoid extra costs on bulk items you will need during the trip. When flying, purchase bulk items like diapers, formula, and wipes at your destination. In the past, it was convenient and free to check these items. Now, each checked luggage item costs $25 or more on average. When driving, do the opposite; take your bulk items to avoid extra trips to the store when you arrive, which can help you avoid impulse travel purchases.

    Bring a full change of clothing for each child. Keep these items within fairly easy reach. When a spill or mess happens, this will help parents avoid unexpected (and unbudgeted) clothing purchases.

    Travel planning can help make family vacations what they are supposed to be: Fun! What are some of your favorite strategies for saving time and stress while traveling with children?

    Kinder Camp

    This is a week-long camp, Monday through Friday, for children from three years old to those entering first grade in the fall. Early childhood educators guide your child through activities including songs, games, stories and walks in the woods. Daily themes include dirt, furry animals, insects and more! Parents sign up to bring a snack (小吃).Choose from either morning or afternoon sessions, from June 9 to July 1& 2019.

    Kids Camp

    Children explore all day in the natural world. Art, music, cooperative games and hikes through the woods are some of the activities in this fun-filled week. Each grade level has its own camp program especially designed with the campers5 interests in mind.

    Camp takes place Monday through Friday, 9 am to 3 pm.

    Level 1 (completed 1st grade): July 28 to August 1, 2019.

    Level 2 (completed 2nd grade): August 4 to 8 2019.

    Level 3 (completed 3rd grade): August 11 to 15, 2019.

    Please note: children must bring their own lunches.

    Outdoor Expeditions

    Send your child on a traveling adventure. Teenagers will investigate the natural, cultural and historical facts that make their hometown a great city. Activities will include unique field trips and tours.

    Outdoor Expedition: from 9 am to 3 pm, August 11 to 15, 2019.

    Please note: children must bring their own lunches.

    Rainbow Camp

    Campers enjoy all kinds of activities including arts and crafts, music and singing, drama, active games, cooking and a host of special events that go with our theme weeks! Special guests are invited to the camp every week to entertain our campers and may include storytellers, musicians and magicians.

Week-long camps, June 14 to July 18.

    Campers must be at least 4 years old to take part.

    For more information, call Frick Environmental Center at (412) 422-6538.

Earth's next superpower

The following countries have been sitting on hidden talents. And now they're about to fly.

NIGERIA (尼日利亚)

Nigeria says it pumps out as much oil as the other two oil-producing countries, Kuwait and Iraq. All this oil is cycling cash into the Nigerian economy and creating extremely rich businessmen. Analysts say that if Nigeria can improve its schools and technology, it could balloon into the world's 13th largest economy by 2050, right between Turkey and Italy. If that reason is not enough for optimism, Nigeria's president also has the sunniest name of any world leader: Goodluck Jonathan.

VIETNAM

As agriculture has given way to industry, unemployment in Vietnam has dropped. What's Vietnam's trick? It's ready to work. Other countries' laborers aren't as cheap as they used to be, which makes Vietnam a relative bargain for companies that need new factories abroad. However, the country has almost no railroads, its highways are in poor condition, and its largest city has just one airport, which was built before the Vietnam War. So what's the use of producing export-ready goods if there's no convenient way to ship them? The good thing is that, however, officials are widening highways, building a new airport and so on.

CHILE (智利)

Pipes, computers, motors, and your microwave all have one thing in common: They're made with copper (铜). Copper makes the world go round. And luckily for Chile, it's got about a third of the planet's copper supply. It just needs a way to dig it up and the government is pouring money into the country's mines.