You may have heard adults say they are uncomfortable in the morning without a cup of coffee. One reason they may feel that way is that coffee contains caffeine(咖啡因). Caffeine appears naturally in coffee, tea, and cocoa beans, which are used to make chocolate. But now food makers are adding it to many products, from potato chips to water.

    The US government is especially worried about the problem. That's why the Food and Drug Administration (FDA) is studying the health effects of caffeine on young people. Studies show that too much caffeine can make people nervous and unable to sleep. What's more, caffeine is habit-forming. Those who consume it regularly and stop suddenly may experience headaches and feel tired.

    One of the biggest concerns is the large amount of caffeine added to so-called energy drinks, like Red Bull. A 12-ounce can of cola has about 35 milligrams of caffeine. A similar serving of Red Bull contains more than three times that amount.

    The Institute of Medicine is also working on caffeine-safety measures. “Teenagers should not drink beverages that contain caffeine. They should be aware of caffeine's effects on health and on how the brain works. Take, for example, teenagers who consume caffeine to stay awake and study for a test. They will remember less of what they just studied,” said Stallings, a member of the institute.

    Companies that make products with added caffeine claim they do not advertise them to kids. However, there is no law to stop children from buying them. So the FDA needs to set limits on caffeine, especially in energy drinks. As for added caffeine in foods, the government should just say no. If not, the amount of caffeine should be printed on food labels to remind consumers. The government must do that.

    Doctors say kids should avoid caffeine. If you need extra energy, try these natural boosters: eat right, exercise, and get plenty of sleep.

    After years of heated debate, gray wolves were reintroduced to Yellowstone National Park. Fourteen wolves were caught in Canada and transported to the park. By last year, the Yellowstone wolf population had grown to more than 170 wolves.

    Gray wolves once were seen here and there in the Yellowstone area and much of the continental United States, but they were gradually displaced by human development. By the 1920s, wolves had practically disappeared from the Yellowstone area. They went farther north into the deep forests of Canada, where there were fewer humans around.

    The disappearance of the wolves had many unexpected results. Deer and elk populations — major food sources (来源) for the wolf – grew rapidly. These animals consumed large amounts of vegetation (植被), which reduced plant diversity in the park. In the absence of wolves, coyote populations also grew quickly. The coyotes killed a large percentage of the park's red foxes, and completely drove away the park's beavers.

    As early as 1966, biologists asked the government to consider reintroducing wolves to Yellowstone Park. They hoped that wolves would be able to control the elk and coyote problems. Many farmers opposed the plan because they feared that wolves would kill their farm animals or pets.

    The government spent nearly 30 years coming up with a plan to reintroduce the wolvers. The U.S. Fish and Wildlife Service carefully monitors and manages the wolf packs in Yellowstone. Today, the debate continues over how well the gray wolf is fitting in at Yellowstone .Elk, deer, and coyote populations are down, while beavers and red fores have made a comeback. The Yellowstone wolf project has been a valuable experiment to help biologists decide whether to reintroduce wolves to other parts of the country as well.

    Who is smarter? A human being or artificial intelligence?

The question swept the world last week when a Google-developed program called AlphaGo defeated the world top player, South Korean Lee Se-dol, 4-1.

    So, what comes next?

    Some people have been arguing that artificial intelligence, or AI in short, will be a bad thing for humans. In an interview with the BBC in 2014, UK scientist Stephen Hawking warned that “The development of full artificial intelligence could mean the end of the human race.”

    So are we really about to live in the world shown in the Terminator movies?

    “Not quite,” answered The Economist. After all, it's not hard to get a computer program to remember and produce facts. What is hard is getting computers to use their knowledge in everyday situations.

    “We think that, for the human being, things like sight and balance(视觉平衡), are natural and ordinary in our life.” Thomas Edison, founder of Motion Figures, a company that is bringing AI to boys, told the newspaper. “But for a robot, to walk up and down just like human beings requires various decisions to be made every second, and it's really difficult to do.”

    As The Economist put it, “We have a long way to go before AI can truly begin to be similar to the human brain, even though the technology can be great.”

    Meanwhile, John Mark off of The New York Times said that researchers should build artificial intelligence to make people more effective.

    “Our fate is in our own hands,” he wrote. “Since technology depends on the values of its creators, we can make human choices that use technology to improve the world.”

    Today the Nobel Prize in Literature awarded journalist Svetlana Alexievich approximately $970,000 in recognition of a lifetime of excellence. The 67-year-old author of Voices From Chernobyl and War's Unwomanly Face was praised by the Swedish Academy "for her polyphonic(复调式的) writings, a monument to suffering and courage in our time."

    Prizes like the Nobel inspire much expectations before the announcement. People give their best guesses as to who will win, look back on past winners, and even place bets as if spectators at a Derby(赛马会).

    Literary prizes reward artistic brilliance. They help writers earn a decent living. But is the public's fascination with prize-winning authors healthy? Our impulse seems to increasingly contribute to a culture of turning authors into celebrities, where readers follow the author instead of the book.

    A story should stand on its own, as a considered, complete book, without biographical information from author. It's an idea perhaps best conveyed in Roland Barthes's 1968 essay The Death of the Author. "The image of literature to be found in contemporary culture is arbitrarily centered on the author, his person, his history, his tastes, his passions."

    Nearly 50 years later, a few still agree. "I believe that books, once they are written, have no need of their authors," New York Times bestselling author Elena Ferrante once wrote. "If books have something to say, they will sooner or later find readers; if not, they won't, "she continued. "True miracles are the ones whose makers will never be known."

    ①But the rules for submission for the Man Booker International Prize, for example, strongly encourage authors to "make themselves available for publicity". And the foundation behind the National Book Award requires finalists to participate in their "website-related publicity".

    ② In 2007, a reporter who showed up uninvited at Doris Lessing's house was the first to inform her that she had been awarded the Nobel Prize in Literature. Today the Twitterati came knocking on Alexievich's digital door hour before the award was even official. To be considered for a prize is to be a public figure.

    ③ Harry Potter series author J. K. Rowling, with over 5.6 million Twitter followers, has actively addressed readers through public appearances and social media, revealing much more than we could have imagined when we closed the final Harry Potter book. We now know the house Harry's children will be sorted into, that Dumbledore is gay," Voldemort" is actually pronounced with a silent "t", and a whole host of the other minor and major details about the backstory of the characters.

    The magical world Rowling created in her books—a relatively tight mystery with well-laid clues that led to a satisfying conclusion, which had to prove their merits to the reader based on an internal logic—is being unraveled by her own hand.

    ④ Of course, public attention also has very important benefits for authors. For three months after receiving the 2011 Pulitzer Prize in fiction, Jennifer Egan's A Visit from the Goon Squad sold about triple its print sales from before the prize, Publishers Weekly reports. On Oct. 5, 2010, in the first FT/Oppenheimer Funds Emerging Voices Awards, as Nigerian-born Chigozie Obioma accepted the prize for fiction with an easy smile, his excitement was appreciable. Given the cash prize of $40,000 for each winner, it's hard to downplay the importance of such an honor. Such awards bring necessary visibility and funding to writers facing a literary landscape dominated by white men.

    But our culture of celebrity is often too wrapped up in the way we read: How might the meaning of a work change if the author really didn't grow up in a poor neighborhood, or if he or she was abused in childhood? Readers studied the author's life as if it were the key to interpreting his or her novels.

    Behind our fascination is the question that drives all such questions: What did the author intend? By all means, let us praise brilliant work and in doing so trust that the author has already told us enough, and that the story he or she meant to tell ended with the final page.

    In San Francisco, where the number of the homeless has risen by 7% in the last decade, a non-profit organization is putting bathrooms on wheels and driving them to those in need. The group, Lava Mae, is improving retiring city buses and bringing them into different neighborhoods, currently providing about 200 showers each week.

    Doniece Sandoval, the founder of Lava Mae, first became interested in the issue in 2012, when she passed a young woman under an overpass near the San Francisco Design Center who was repeating to herself that she'd never get clean. "It made me wonder what her chances were," said Sandoval, who was then inspired to research exactly how many public shower stalls（淋浴间）existed in the city. Her findings were disheartening.

    So Lava Mae came together when she heard the city would be retiring cold city buses. "I told myself, I want those buses!" she said.

    Each bus has two private bathrooms, one of which is wheelchair accessible. Along with the basic shower, sink and toilet, the spaces have soft lighting, digital controls for water, and hair dryers.

    "Though you're only going to be on the bus for 20 minutes or so, it's 20 minutes of complete privacy," Said Sandoval.

    The buses are parked near agencies that already serve the homeless. "If we can reduce the amount of time people have to run from place to place to get essential services, we'll be able to make things better," said Sandova.

    What's next for lava Mae? The group is starting a program so that others can mimic their process. " What we're hoping to do is to get people to follow what we do, so they can recreate it." she said.

Macquarie Island is a tiny island that's part of Australia. It's about halfway between New Zealand and Antarctica. The island's been made a world heritage area because it's so untouched, but this unique environment is under threat from some unwanted visitors.

It all started when seal hunters came to the island in the early 1800s. They brought rabbits with them as a source of food for the journey, and also on board the ships were rats and mice, which made their way onto the island too. They're being blamed for destroying the homes of marine birds, causing soil loss and ripping up plant cover, as these before-and-after photos show.

So what's being done about the problem? It starts with a team of helicopters that fly across the island carrying these giant containers. Inside them are poisoned pellets (有毒饲料) which are dropped and spread across the island. For any rabbits that survived the baiting (诱饵) , there's a plan B. This special team of dogs is being put through a final training. It'll be their job to track down any remaining rabbits. They have to also learn to behave around the island's native wildlife. The dogs could be here for years or until the task is complete. The dogs don't actually kill the rabbits. They find them, then the hunters decide to either catch the rabbits or shoot them.

But the program has received a bit of criticism. Some people argue 25 million dollars is a lot of money to be spending on wiping out rabbits and rodents (啮齿目动物), and in the process, some native birds will be killed because of the baiting. 

The reality is the problem isn't going to be solved overnight. The people running the program say that even if one pair of rabbits is left alive, the whole task will be seen as a failure, which means these guys could be here for a long time, trying to ensure that this precious island remains protected from pests.