Since the 1970s, scientists have been searching for ways to link the brain with computers. Brain-computer interface (界面) (BCI) technology could help people with disabilities send commands to machines.

    Recently, two researchers, Jose Milan and Michele Tavella from the Federal Polytechnic School in Lausanne, Switzerland, demonstrated（展示）a small robotic wheelchair directed by a person's thoughts.

    In the laboratory, Tavella operated the wheelchair just by thinking about moving his left or right hand. He could even talk as he watched the vehicle and guided it with his thoughts.

    “Our brain has billions of nerve cells. These send signals through the spinal cord (脊髓) to the muscles to give us the ability to move. But spinal cord injuries or other conditions can prevent these weak electrical signals from reaching the muscles,” Tavella says.  “Our system allows disabled people to communicate with external world and also to control devices.”

    The researchers designed a special cap for the user. This head cover picks up the signals from the scalp(头皮) and sends them to a computer. The computer interprets the signals and commands the motorized wheelchair. The wheelchair also has two cameras that identify objects in its path. They help the computer react to commands from the brain.

    Prof. Milan, the team leader, says scientists keep improving the computer software that interprets brain signals and turns them into simple commands. “The practical possibilities that BCI technology offers to disabled people can be grouped in two categories: communication, and controlling devices. One example is this wheelchair.”

    He says his team has set two goals. One is testing with real patients, so as to prove that this is a technology they can benefit from. And the other is to guarantee that they can use the technology over long periods of time.

    A new report shows that there are just 7,100 cheetahs now left in the wild. Cheetahs are in trouble now.

    According to the study, more than half of the world's surviving cheetahs live in one zone that covers six countries in southern Africa. Cheetahs in Asia have nearly died out. It's thought that only fewer than 50 cheetahs live in Iran.

    The cheetah runs across lands far outside protected areas. Some 77% of their habitat falls outside these protected areas. As a result, the cheetah struggles because these lands are increasingly being developed by farmers and the cheetah's food is decreasing because of human hunting.

    In Zimbabwe, the cheetah population has fallen from around 1,200 to just 170 in 16 years, with the main cause being major changes in land ownership.

    Researchers say that the threats cheetahs are facing have gone unnoticed for far too long. “Given the nature of the cheetah, it has been difficult to gather information on them,” said Dr Sarah Durant, the report's lead author. “Our findings show that the large space requirements for cheetahs and various threats faced by them in the wild mean that they are likely to be in danger of dying out.”

    Another big concern about cheetahs has been the illegal trafficking (非法交易) of young cheetahs. The young cats can fetch up to $10,000 on the black market. Some 1,200 young cheetahs are known to have been trafficked out of Africa over the past 10 years but around 85% of them died during the journey.

    If the cheetahs are to survive, then immediate efforts must be made.

    As I was thinking about language learning the other day, the image of baking bread came into my mind. I compared some of the exercises and drills that we put ourselves through in order to learn a language to the various ingredients that go into baking a loaf of fresh bread.

    Real language learning takes place in human relationships. No one sits down and eats a cup of flour, even if he is hungry and in a hurry. You don't become bilingual（双语的）by learning lists of vocabulary. You don't become a speaker of a language by memorizing verb conjugations（动词的词形变化）and agreement rules. You become bilingual by entering a community that uses that other language as its primary means of communication.

    I am not suggesting that we can make bread without ingredients. Flour is necessary, as are yeast, salt, water and other ingredients. Vocabulary is part of any language and will have to be learned. Grammatical rules exist in every language and cannot be ignored. But merely combining the appropriate ingredients in the recommended proportions does not result in bread. At best, you only end up with a ball of dough（面团）.

    In order to get bread, you have to apply heat to the dough. And in language learning, that heat comes from the community. Anyone who has learned a second language has experienced that heat. It creeps up your neck when you ask the babysitter, “Have you already been eaten?” when you meant to say, “Have you already eaten?” When you try to say something quite innocent and the whole room bursts into laughter, you are experiencing the heat that turns raw dough into good bread.

    Remember the old saying, “If you can't stand the heat, get out of the kitchen”? This is where language learning often breaks down because we find the heat uncomfortable and we stop the baking process. In other words, we can't stand the heat, so we get out of the kitchen.

    However, the language learner who stays in the kitchen—in the heat—until the combined ingredients are thoroughly transformed will enjoy the richness of a quality loaf of bread. He said that he did not “get out of the kitchen” at the critical moment when the oven seemed too hot. The dedicated language learner knows that becoming bilingual cannot be achieved without the heat!

    About a month after I joined Facebook, I got a call from Lori Goler, a highly regarded senior director of marketing at eBay. She made it clear this was a business call. "I want to apply to work with you at Facebook," she said. "Instead of recommending myself, I want to ask you: What is your biggest problem, and how can I solve it?"

    My jaw hit the floor. I had hired thousands of people over the previous decade and no one had ever said anything remotely like that. People usually focus on finding the right role for themselves, with the implication that their skills will help the company. Lori put Facebook's needs front and center. It was a killer approach. I responded, "Recruiting is my biggest problem. And, yes, you can solve it."

    Lori never dreamed she would work in recruiting, but she jumped in. She even agreed to trade earnings for acquiring new skills in a new field. Lori did a great job running recruiting and within months was promoted to her current job, leading People@Facebook.

    The most common metaphor for careers is a ladder, but this concept no longer applies to most workers. As of 2010, the average American had eleven jobs from the ages of eighteen to forty-six alone. Lori often quotes Pattie Sellers, who came up with a much better metaphor: "Careers are a jungle gym, not a ladder."

    As Lori describes it, there's only one way to get to the top of a ladder, but there are many ways to get to the top of a jungle gym. The jungle gym model benefits everyone, but especially women who might be starting careers, switching careers, getting blocked by external barriers, or reentering the workforce after taking time off. The ability to create a unique path with occasional dips, detours (弯路), and even dead ends presents great views of many people, not just those at the top. On a ladder, most climbers are stuck staring at the butt of the person above.

    When Shakespeare was twenty-one, he went to London, a very interesting place, to try his fortune.

    There was the famous London Bridge and St. Paul's Cathedral, and palaces and markets and long streets full of shops.

    Then, too, there were the daily crowds where could be seen people from all over the world. Knights, scholars and the highwayman (拦路强盗）or thieves, who had been infamous for their clever robberies, passed by each other.

    Here, also, were noblemen dressed in gold, from Italy and Spain and France; slaves from Spanish America, sea captains and ministers, soldiers and servants—all held by chances or interests within the gray walls which circled London, and whose gates gave welcome to as strange a crowd as could be found in the world.

    Into this curious crowd came Shakespeare, quick to see and eager to learn. And before long all these strange sights were as familiar to him as the faces of his own town's residents. Each one told its story to him so plainly that, as before he had learned the secrets of the fields and woods, so now he learned men and men's interests that make up the great world.

    And he learned these lessons so well that when he came to write his plays, he made such use of them as no writer ever made before or since; for it is the use of this knowledge of the world, combined with his own genius, that makes Shakespeare the greatest dramatist that has ever lived.