Ever feel like you've been hit on the head after a bad night's sleep? According to scientists, the thought isn't as unbelievable as it seems.

    A study found going without sleep for just one night causes changes in the brain similar to those that occur after a blow to the head. The researchers said the healthy young men examined in the study showed a sudden increase in the same chemicals which indicate brain damage. Professor Christian Benedict, of Uppsala University, Sweden, explained that the chemicals NSE and S-100B are biomarkers for brain damage, such as concussion(脑震荡). He said, "What we found was their levels in the blood rose in the group that went without sleep for a night. This was not to the extent that would happen after a head injury, for instance, but it was still significant. During sleep, the brain cleans poisonous substances off itself."

    Benedict also said previous studies which linked a lack of sleep with increased risk of Alzheimer's, Parkinson's and multiple sclerosis could applaud his study. The rise of the chemicals in the blood after sleep loss may suggest not getting enough sleep contributes to a loss of brain tissue, he explained. Benedict, whose study is published in the journal Sleep, added, "In conclusion, the findings of our experiment indicate a good night's sleep may be critical to maintaining brain health."

    A third of the UK population suffer from sleep-related problems, while the average person now sleeps for only seven hours a night, compared with almost nine a few decades ago. Many scientists believe irregular sleeping patterns lead to illnesses ranging from aches and pains to heart disease, while less than eight hours' sleep a night can lower the IQ the next day.

    A disease called “Panama” is threatening supplies of the world's most popular fruit—banana.Two years ago,the United Nations warned that the "Panama disease" could destroy "much of the world's banana crop."Since then,things have not gotten better.A new outbreak was discovered last year in Australia.The disease started in Asia in the 1990s, and later spread to Africa and the Middle East.

    World health officials worry the disease could travel to Latin America,one of the top banana producers in the world.All this is a big concern because bananas are an important source of income and nutrients for millions of people.They are grown in 135 tropical nations.The United Nations lists bananas as one of the most important foods, along with rice,wheat and corn.

    Randy Ploetz is a professor at the Tropical Research & Educational Center at the University of Florida.Many consider him as America's top banana expert.As he explained,Panama disease affects the Cavendish banana.The Cavendish is one of more than 500 kinds of bananas.But it is the most popular.

    “The industry is waking up to the problem,”Ploetz said.“They are pretty scared.”He was speaking Thursday by telephone from Miami,Florida,where he is among 1,000 people attending the International Banana Congress.The meeting was supposed to take place in Costa Rica,but was moved at the last minute.There were concerns banana growers could spread Panama disease from dirt collected on their shoes,Ploetz said.

    Ploetz said reports that Cavendish banana production could end are not correct.But if the disease spreads to Latin America,it could hurt the world's economy along with food supplies for millions of people.Still,he said there is reason for hope.Scientists in Australia are working on a genetically engineered banana that might not be at risk of getting Panama disease.

    Self-driving cars have been backed by the hope that they will save lives by getting involved in fewer crashes with fewer injuries and deaths than human-driven cars. But so far, most comparisons between human drivers and automated vehicles have been unfair.

    Crash statistics for human-driven cars are gathered from all sorts of driving situations, and on all types of roads. However, most of the data on self-driving cars' safety have been recorded often in good weather and on highways, where the most important tasks are staying in the car's own lane and not getting too close to the vehicle ahead. Automated cars are good at those tasks, but so are humans.

    It is true that self-driving cars don't get tired, angry, frustrated or drunk. But neither can they yet react to uncertain situations with the same skill or anticipation of an attentive human driver. Nor do they possess the foresight to avoid potential perils. They largely drive from moment to moment, rather than think ahead to possible events literally down the road.

    To a self-driving car, a bus full of people might appear quite similar to an uninhabited corn field. Indeed, deciding what action to take in an emergency is difficult for humans, but drivers have sacrificed themselves for the greater good of others. An automated system's limited understanding of the world means it will almost never evaluate (评估) a situation the same way a human would. And machines can't be programmed in advance to handle every imaginable set of events.

    Some people may argue that the promise of simply reducing the number of injuries and deaths is enough to support driverless cars. But experience from aviation (航空) shows that as new automated systems are introduced, there is often an increase in the rate of disasters.

    Therefore comparisons between humans and automated vehicles have to be performed carefully. To fairly evaluate driverless cars on how well they fulfill their promise of improved safety, it's important to ensure the data being presented actually provide a true comparison. After all, choosing to replace humans with automation has more effects than simply a one-for-one exchange.

    Right in front of the Minneapolis Central Library, a row of green hikes sits parked in a special stand. Each hike is designed with the logo "Nice Ride" the name of the city's bike-share program.

    Nice Ride bikes are a lot like the library books that people come here to borrow. To rent a bike, you simply use your membership card at a Nice Ride bike station. Members can rent one of 1, 200 bikes from 138 stations throughout Minnesota's largest city. People use the Nice Ridebikes to go to work, to go out on business, or just to enjoy the city's many bike paths.

    The rise of bike-share programs like Nice Ride is encouraging more people than ever to choose biking over driving. Skyrocketing gas prices and concerns about the environment have also gotten people to dust off their bike helmets, pump air into flat tires, and hit the road.

    Why ride? Not only is biking good exercise, but switching from a car to a bike also reduces the amount of pollution in the air. Carbon dioxide, a greenhouse gas linked to climate change, is one of the many polluting substances that come out of a car's tailpipe.

    Bike-share systems are found around the world in cities like London, Paris, Barcelona, and Melbourne, Australia. The largest program—with 70, 000 bikes—is in Wuhan, China.

    To make roads friendlier to non-motorists, the U. S. Department of Transportation has invested more than a billion dollars in cycling and pedestrian projects in recent years. The money went toward building thousands of miles of on-street bike lanes and bike-and pedestrian-only passages called greenways.

    Facebook says it is working on technology to allow us to control computers directly with our brains. It is developing "silent speech "software to allow people to type at a rate of 100 words per minute, it says. The project, in its early stages, will require new technology to detect brainwaves without needing invasive operation. "We are not talking about monitoring your random thoughts," assured Facebook's Regina Dugan. "You have many thoughts, and you choose to share some of them. We're talking about monitoring those words. A silent speech interface（界面）-one with all the speed and flexibility（灵活）of voice. "

    Ms Dugan is the company's head of Building 8, the firm's hardware research lab. The company said it intends to build both the hardware and software to achieve its goal, and has employed a team of more than 60 scientists and academics to work on the project.

    On his Facebook page, Mark Zuckerberg added, "Our brains produce enough data to stream four HD（高清）movies every second. The problem is that the best way we have to get information out into the world-speech-can only send about the same amount of data as a 1980s modem. We're working on a system that will let you type straight from your brain about five times faster than you can type on your phone today. Finally, we want to turn it into a wearable technology that can be produced in quantity. "

    Technology is going to have to get a lot more advanced before we can share a pure thought or feeling. but this is a first step. Other ideas detailed at the company's developers conference in San Jose included work to allow people to "hear" through skin. The system, comparable to Braille, uses pressure points on the skin to pass information. "One day, not so far away, it may be possible for me to think in Chinese, and you to feel it instantly in Spanish,"Ms Dugan said.

Norwegians would perhaps highlight their custom of "gå på tur"— going on a journey on foot or on skis. In Denmark, everyone knows what "hygge" is — to freely enjoy the good life with the people you love. They're the issues of "intangible cultural heritage", things that cannot be physically touched such as traditions, stories, music, dance and craft skills.

In 2003, UNESCO, the education, science and culture organization of the United Nations, adopted an agreement to "preserve the intangible" and many developing-world countries were quick to get their traditions included on the official list. But it would take almost 10 years for "Agreement for the Safeguarding of the Intangible Cultural Heritage" to be approved by the Scandinavian countries.

Annika Sjöberg is responsible for managing the work of the agency in Sweden. She has been, and continues to be, flooded with suggestions of intangible cultural heritage worthy of protection, submitted by committed citizens and organizations wanting to see their particular traditions included on the list that should be ready sometime in the next couple of years.

Suggestions have also been received concerning various maritime traditions: old shipwright skills such as the building of wooden hulled vessels, are in decline and at risk of being lost forever.

"Our work has attracted considerable attention as it is regarded as being a little out in left field," says Sjöberg. "In addition, it's also opened people's eyes to the fact that the things we can't physically touch indeed have a major bearing on the way in which we live. Even in an urbanized society, there is knowledge we carry with us that we've inherited from previous generations-knowledge that's important to preserve and take care of."

Sjöberg explains that the point is not to preserve this cultural heritage in a stony rigid form, as traditions must be allowed to change and evolve. She also emphasizes that her work should not be interpreted as a nationalistic project, rather as a means of multicultural spreading.

It's actually a matter of documenting the knowledge that exists in the various traditions. What is most exciting is the diversity that now exists and the ways in which different cultures interact with each other.