American researchers found females are the more talkative sex because of a special “language protein” in the brain.

    The study, conducted by neuroscientists (神经学家) and psychologist from the University of Maryland, concluded that women talked more because they had more of the Foxp2 protein. The research, published in the Journal of Neuroscience, found that higher levels were found among humans that were women but in rats that were males. Their findings came after it was previously claimed that ladies speak about 20,000 words a day — over 13,000 more than men. “This study is one of the first to report a sex difference in the expression of a language-associated protein in humans or animals,” said Prof Margaret McCarthy, who led the study. In their study, the researchers attempted to determine what might make male rats more vocal than their female friends.

    They separated four-day-old rats from their mothers and then counted the number of times they cried out in the “ultrasonic (超声波的) range”, the frequencies higher than humans can hear, over five minutes. While both sexes called out hundreds of cries, the males called out twice as often, they found. But when the pups were returned to their mother's cage, she fussed over her sons first. Tests conducted on the parts of the brain known to be associated with vocal calls showed the male pups have up to twice as much Foxp2 protein as the females. The researchers then increased the production in the brains of female pups and reduced it in males. This led to the female rats crying out more often and their mothers showing more interest in them. In contrast, males became less “talkative”.

    The researchers then tested samples from ten children, aged between three and five, which showed that females had up to 30 per cent more of the Foxp2 protein than males, in a brain area key to language in humans.

    “Based on our observations, we assume higher levels of Foxp2 in girls and higher levels of Foxp2 in male rats is an indication that Foxp2 protein levels are associated with the more communicative sex,” said Prof McCarthy.

    “Our results imply Foxp2 as a component (成分) of the neurobiological basis of sex differences in vocal communication in mammals.”

    If you are interested to find a part time job or learn something different during your spare time, you can have a look at the following jobs offered by the DC Public Library.

Teens of Distinction Program

    The DC Public Library offers part time jobs for teens through the Teens of Distinction Program. Teens work 10-12 hours per week all year long, helping the library with important tasks and projects. The Teens of Distinction Program is now hiring! To apply, you have to：

● be a DC resident

● have and maintain at least a 2.5 grade point average

● be 16 to 18 years old

● be able to work 10-12 hours per week

● be able to work for DCPL for at least 9 months

Oh, and of course you have to impress us with your wonderful personality!

Teen Volunteer Opportunities

    If you want to earn community service hours for school, Youth202 is a good choice.

    Youth202 is a radio program created by youth and for youth. You can learn radio production skills, interview people around you, and help keep other teens to learn news, events, and anything else you think is important.

Summer Youth Employment Program (SYEP)

    Every summer, teens can work here to help library customers organize books and learn lots of new skills, such as program planning, writing and media production.

    On Friday, January 25 at 12:15 pm, the application for the 2014 SYEP will be open to teens between the ages of 14 and 21.

    Applications will be processed on a first come, first served basis. Space is limited this year, so teens are encouraged to apply early, and remember not to miss the deadline, Saturday, February 16.

    Why we cry with happiness show: Responding with a negative reaction helps us deal with extreme joy. If you cry with happiness at weddings, you are responding to a happy experience with a negative reaction. The researchers believe the unusual reaction may help renew emotional balance in us and keep extreme emotions under control. The findings make it clear how people express and control their emotions, which could help improve their understanding of people's mental(精神的) health.

    Dr Oriana Aragon set out to explore the phrase “tears of joy”, which she said never made sense to her. But after studying a series of incongruous(不和谐的) expressions, she now understands better why people cry when they are happy. “People may be renewing emotional balance with these expressions,” she explained. “They seem to take place when people are struck by strong positive emotions. People, who do this, seem to recover better from those strong emotions.”

    The report show various examples of responding to a positive experience with a negative emotion, such as, a crying wife seeing the husband returning from war again, and teenage girls screaming at a Justin Bieber concert. Examples also include a baseball player who hits a home run, only to be slapped(拍) on the back by teammates, as well as when people cannot help kissing babies' faces who they consider lovely.

    Dr Aragon and her team discovered that people, who expressed negative reactions to positive news, were able to moderate(缓和) strong emotions more quickly. There is also some evidence that strong negative feelings may provoke positive expressions. For example, nervous laughter often happens when people are faced with a hard situation. We've seen people smiling during times of extreme sadness.

    “The findings affect our knowledge of how people express and control their emotions, which is importantly related to mental and physical health, the quality of relationships with others, and even how well people work together,” Dr Aragon said.

    While staring out of the window during a flight, not everyone will think carefully about the question why airplanes have rounded windows rather than square ones.

    Over the years, aerospace engineering has made huge steps in airplane technology, meaning planes can carry more passengers and go faster. The planes have also changed shape to increase safety—including the windows. As commercial air travel took off in the mid－20th century, airline companies began to fly at higher altitudes to lower their cost—the air density(密度) is lower up there, creating less drag(阻力)for airplanes. However, higher altitudes came with problems, like the fact human beings can't really survive at 30，000 feet. To make that possible, the cabin was changed to a cylindrical(圆柱体) shape to support the pressure inside. But at first, plane builders left in the standard square windows and this expansion meant disaster. The de Havilland Comet came into fashion in the 1950s. With a closed cabin, it was able to go higher and faster than other aircraft.

    However, where there's a corner, there's a weak spot. Windows, having four corners, have four potential weak spots, making them likely to crash under stress—such as air pressure. By curving the window, the stress that would eventually break the window corner is distributed and the chance of it breaking is reduced. Rounded shapes are also stronger and resist deformation(变形), and can thus survive the extreme differences in pressure between the inside and outside of the aircraft.

    Fortunately, designers figured out the lack of design pretty quick. Now we have nice, rounded airplane windows that can resist the pressure of traveling altitude. It gives being able to gaze out of your window to the world from 35，000 feet a whole new outlook, doesn't it?

    Arthur Dubois isn't your typical grandfather. That's because at 72 years old, the Chicago resident is a newly discovered hip-hop artist.

    This week, Dubois walked into Haven Studios, a music program on the South Side of Chicago that supports young ambitious artists. The owner of Haven Studios, Andre "Add-2" Daniels, said Dubois claimed he was "young at heart." So, Daniels decided to listen to Dubois' music. He was completely floored. Daniels quickly took videos showcasing Dubois' talents and posted them to Twitter. His tweet went viral, receiving thousands of reactions within a matter of days. Now, Dubois' talents have even caught the attention of some famous hip-hop producers.

    "It's not what you would expect, right?" Daniels says in one of the videos. Dubois music is playing in the background, giving a steady beat that easily invites listeners to dance.

    Dubois said his style was entirely self-taught. He first started teaching himself to produce hip-hop beats about six years ago, after he retired. "I found something to do," he told NPR's Scott Simon. "I had to learn how to do the computer and music at the same time." Dubois taught himself by using the audio editing software. Now he's learning another new skill-social media. Dubois' newfound social media fame has been a little overwhelming for him. "I was shocked," he said. "I broke down and cried because I didn't know that many people liked me." Daniels has helped Dubois set up accounts on Twitter and Instagram for his fans to follow, "I'd never used Instargram, Twitter and all that other stuff," Dubois said. "Because I didn't believe in that stuff myself. But now I've got to have it." The attention doesn't seem to have gone to Dubois' head though-he doesn't really care about getting famous or making money. "I just want to put it out there and let other people hear my music."