The new mayor of Hillsdale, Michigan, is a man of the people, ready to listen to their problems, but only until 6 p.m. Then he has to do his homework. Michael Sessions, 18, beat former mayor Douglas Ingles, 51, by just two votes and became the new mayor of Hillsdale. He is America's youngest mayor.

    As Sessions was too young to enter the election in the spring of 2005, he registered to vote on Sept, 22, one day after his 18-year-old birthday. The day after that he started his write-in campaign, which means he should persuade voters to remember his name and write it by hand on the voting ballots（选票）.

    To help get his name known, Sessions earned＄700 by selling apples over the summer. He spent the money on posters and put them on the Hillsdale's lawns.

    Sessions' month-long campaign included going door to door, explaining his ideas of the town's future in the kitchens of his neighbors. "They'd look at me, and say‘How old are you again? How much experience do you have?' And I say ‘I'm still in high school', " he said. Sessions promised Hillsdale's voters he would renew local economy. “I was hopeful the whole time, ” he explained. One day he spent so long out on the streets knocking on the doors that he ended up in a hospital emergency room.

    Sessions said that his schoolwork will not get in the way of his job as a mayor. “From 7:50 a.m. to 2:30p.m., I'11 be a student. From 3 to 6, I'11 be the mayor of Hillsdale," he said.

    “He did a very brave thing that couldn't have been easy for him to do, "said Jack Vettel, a councilman in Hillsdale, a city of 8,200 about 75 miles southwest of Detroit. "He does care about this town. He's been here all his life.”

    Sessions will receive＄3, 600 a year during this four-year term, and will work out of his bedroom since the town does not provide the mayor with an office.

    Are you looking for some new and exciting places to take your kids to? Try some of these places.

    Visit art museums. They offer a variety of activities to excite your kids' interest. Many offer workshops for making hand-made pieces, traveling exhibits, book signings(签名) by children's favorite writers, and even musical performances and other arts.

    Head to a natural history museum. This is where kids can discover the past from dinosaur(恐龙) models to rock collections and pictures of stars in the sky. Also, ask what kind of workshops and educational programs are prepared for kids and any special events that are coming up.

    Go to a Youtheater. Look for one in your area offering plays for child and family visitors. Pre-show play shops are conducted by area artists and educators where kids can discover the secret about performing arts. Puppet(木偶) making and stage make-up are just a couple of the special offerings you might find.

    Try hands-on science. Visit one of the many hands-on science museums around the country. These science play-lands are great fun for kids and grown-ups alike. They'll keep your child mentally and physically active the whole day through while pushing buttons, experimenting, and building. When everyone is tired, enjoy a fun family science show, commonly found in these museums.

    I was reading these interesting stories behind a group of great logos in the world. Personally Nike is my favorite one—it's so simple. And I like the stories behind them, which made me forget all other things. McDonald's, Apple, Mercedes Benz and Adidas own great logos as well, and they are among my favorites.

    Nike

    In the Greek myth, Nike is the goddess of victory and the source of inspiration for soldiers. This logo represents the wing in the famous statue of the Greek goddess. Nike's logo was designed by Carolyn Davidson in 1971 for $35, and was registered as a trademark in 1995.

    McDonald's

    The logo was designed in 1962 by Jim Schindler to resemble the arch-shaped(拱形的) signs on the side of the company's then walk-up hamburger stand. Later on, the two golden arches were combined together to form the M. The McDonald's name was added to the logo in 1968.

    Apple

    There are different stories behind Apple's logo. The first logo was a reference to the religious story of Adam and Eve, in which the apple represented the fruit of the Tree of Knowledge. One year later, the second logo was designed in 1977 by Steve Jobs and Ronald Wayne, and it described Sir Isaac Newton sitting under an apple tree. This logo didn't stay long. One year later it was replaced almost immediately by graphic designer Rob Janoff's "rainbow apple", a rainbow-colored silhouette(轮廓) of an apple with a bite taken out of it. And then the rainbow-colored apple was replaced by the one-colored logo in 1998. It has not been changed so far.

    Mercedes Benz

    The Mercedes Benz logo, which was originally created by Gottlieb Daimler in 1909, consists of a simple description of a three-pointed star that represents its rule of the land, the sea and the air. The company was founded by Gottlieb Daimler and Wilhelm Maybach. Mercedes is the name of Maybach's elder daughter, while Benz came as a result of a combination with Benz, Cie and DMG in 1926.

    Adidas

    The Adidas logo, which was created by the founder of the company Adi Dassler, represents mountains, pointing towards the challenges that are seen ahead and goals that can be achieved. The logo was used for the first time in 1967.

    Do you know the difference between a food chain anda food web? Food chains show how a living thing such as a plant or an animal gets its energy. A food web consists of multiple food chains and includes many more plants and animals than a food chain includes. This diagram shows a food chain within a food web of the African savanna.

    Sweet potato plants don't have spines or poisons to defend themselves. But some have evolved a clever way to let hungry herbivores (食草动物) know they aren't an all-you-can-eat buffet, a new study finds. When one leaf injured, it produces a chemical that warms the rest of the plant and its neighbors to make themselves inedible (不宜食用的)to bugs. Sweet potato breeders could potentially engineer plants to produce the chemical as an all-natural pest defense.

    Plant ecologists led by Axel Mithofer of the Max Planck Institute for Chemical Ecology in Jena, Germany, started to look into sweet potato (Ipomoea batatas) defenses after they noticed something interesting about two varieties of the plant grown in Taiwan: The yellow-skinned, yellow-fleshed Tainong 57 is generally herbivore-resistant, but its darker orange cousin, Tainong 66, is plagued (造成麻烦) by insect pests.

    To find out why, the team offered up Tainong 57 and 66 plants to hungry African cotton leafworm caterpillars (毛虫).Both plants released at least 40 airborne compounds as the caterpillars snacked on their leaves. But Tainong 57 produced a lot more of a chemical called DMNT, which has a very distinct smell, the team details this month in Scientific Reports. ("The smell is not nice," Mithofer says. "You wouldn't want it as a perfume.")

    DMNT isn't a new compound; researchers have isolated (分离出) the smelly chemical from other plants such as corn and cabbage, and it is known to induce defense responses in some species.

    To determine whether this was happening in sweet potatoes, scientists set up two experiments. First, they put two plants next to each other and wounded one so it produced DMNT. Then, they exposed healthy Tainong 57 plants to DMNT they had synthesized (合成).In both cases, the DMNT caused the exposed plants to produce more of a protein called sporamin in their leaves. (Tainong 66 did not have the same reaction.) When the caterpillar's snack on sporamin, "they immediately stop eating because they don't feel well," Mithofer says.

    Sporamin is the main protein in sweet potato tubers (块茎),and is indigestible raw, which is why sweet potatoes must be cooked for humans to enjoy them. "If the caterpillars could cook it, they could eat it," Mithofer says. Theoretically, he says, sweet potato breeders could use genetic engineering to make different varieties of sweet potato produce as much DMNT as Tainong 57, and display the same defense responses.

    Still, the research isn't ready for prime time, cautions plant ecologist Martin Heil. DMNT might work in the lab, but in the field, airborne chemicals can be "blown away in seconds," says Heil, who studies plant-insect interactions at the National Polytechnic Institute in Irapuato, Mexico.

    Mithofer himself has no plans now to create genetically engineered sweet potato plants, because they would not be a viable (能活下去的) crop in Europe, where genetically modified crops are outlawed. So for now, Tainong 66 will have to put up with being a caterpillar salad bar.

A researching team analyzed data from long-running studies conducted in Brazil and South Africa to assess whether children exposed to early adversities (逆境), such as extreme poverty, low birth weight, and pre-term birth, could reach their full learning potential by experiencing responsive caregiving and opportunities to learn in their home. They found that early life adversities matter throughout life. Teenagers who had been exposed to multiple adversities early in life had lower IQ scores, were more likely to have difficulties adjusting socially and psychologically, and achieved a lower physical height compared to teenagers exposed to fewer adversities. They also found that being raised in a nurturing (培育) environment could significantly counteract the negative effect of early adversities on IQ and help children achieve their full potential of intelligence.

Globally, more than 250 million children younger than 5 years are at risk of not reaching their developmental potential because of adversities that co-occur early in life and worsen with age. In the US, almost one in five children are raised in poverty and 15 percent do not complete high school. Exposing these children to a nurturing environment, whether at home or in daycare or pre-school settings, can lead to cognitive (认知的) benefits that last into teenage and beyond.

Parents should provide nurturing environments, which include interacting with young children in a positive way such as reading children's books from the library, singing songs together, and playing games with numbers and letters. Children who join in age-matched housework like picking up toys and clearing the table gain skills and feel good about helping. Get children involved in friendly activities as much as possible rather than park them in front of a screen. Children love to learn and in a nurturing environment, they can grow into teenagers and adults with the abilities to care for themselves, their families, and their communities.