Bad news sells. If it bleeds, it leads. No news is good news, and good news is no news. Those are the classic rules for the evening broadcasts and the morning papers. But now that information is being spread and monitored(监控) in different ways, researchers are discovering new rules. By tracking people's e-mails and online posts, scientists have found that good news can spread faster and farther than disasters and sob stories.

    “The 'if it bleeds' rule works for mass media,” says Jonah Berger, a scholar at the University of Pennsylvania. “They want your eyeballs and don't care how you're feeling. But when you share a story with your friends, you care a lot more how they react. You don't want them to think of you as a Debbie Downer.”

    Researchers analyzing word-of-mouth communication—e-mails, Web posts and reviews, face-to-face conversations—found that it tended to be more positive than negative(消极的), but that didn't necessarily mean people preferred positive news. Was positive news shared more often simply because people experienced more good things than bad things? To test for that possibility, Dr. Berger looked at how people spread a particular set of news stories: thousands of articles on The New York Times' website. He and a colleague analyzed the “most e-mailed” list for six months. One of his first findings was that articles in the science section were much more likely to make the list than non-science articles. He found that science amazed Times' readers and made them want to share this positive feeling with others.

    Readers also tended to share articles that were exciting or funny, or that inspired negative feelings like anger or anxiety, but not articles that left them merely sad. They needed to be aroused(激发) one way or the other, and they preferred good news to bad. The more positive an article, the more likely it was to be shared, as Dr. Berger explains in his new book, “Contagious: Why Things Catch On.”

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    From The 12 Days of Christmas to See You in the Cosmos, these children's books are ideal for holiday giving.

    The 12 Days of Christmas by Greg Pizzoli

    It's a classic Christmas reading material! It's a counting lesson! It's a crazy tale of elephant love. Have you ever wondered how all those calling birds, turtle doves and French hens fit in one room? Pizzoli, a Theodor Seuss Geisel Award winner has your answer. ($ 15.99, ages 3—5) Amazon. com

   Here We Are by Oliver Jeffers

    Yes, this book by the illustrator (插画家) of the great hit “The Day the Crayons Quit” is for kids ages 3—7, but don't let that fool you.     Inspired by the birth of Jeffers1 first child, this is a father's “welcome to the earth” letter to his baby, filled with the heady wonder of parenthood .A great gift for new parents. ($ 19.99. ages 3—7) Amazon. com

    Wishtree by Katherine Applegate, illustrated by Charles Santoso.

     When a towering oak tree learns that she may be cut down, she starts getting extraordinarily involved in the lives of the humans below her, particularly a girl who is being escaped due to her ethnicity (种族). A lovely tale about common ground and the power of community. ($ 16.99, ages 8 —12) Amazon. com

     See You in the Cosmos by Jack Cheng

    Eleven-year-old Alex is too busy trying to communicate with space aliens to worry about his troubled family life. When Alex runs away from home to launch his homemade rocket, he finds himself sidetracked by new friends and hints of a family secret. ($ 16.99, ages 10 and up) Amazon. com

    Many people have long dreamed of being able to fly around as simply as riding a bicycle. Yet the safety and strength of a flying bike was always a big problem. Over the past 10 years, developments in technology have moved the dream of personal flying vehicles closer to reality. Now, two groups of inventors say such vehicles may be available soon.

    The British company Malloy Aeronautics has developed a prototype (原型) of its flying bicycle. Grant Stapleton, marketing sales director of Malloy Aeronautics, says the Hoverbike is able to get in and out of small spaces very quickly." It can be moved across continents very quickly because it can be folded and packed," he adds.

    Mr. Stapleton says safety was the company's main concern. He says the designers solved the safety issue by using overlapping rotors to power the vehicle.

    The company is testing a full-size prototype of the Hoverbike, which will most likely be used first by the police and emergency rescue teams.

    In New Zealand, Martin Aircraft Company is also testing a full-size prototype of its personal flying device, called the Jetpack. It can fly for more than 30 minutes, up to 1, 000meters high and reach a speed of 74 kilometers per hour.

    Peter Coker is the CEO of Martin Aircraft Company. He said the Jetpack "is built around safety from the start". In his words, “Reliability is the most important element of it. We have safety built into the actual structure itself, very similar to a Formula One racing car.

    The Jetpack uses a gasoline-powered engine that produces two powerful jet streams. Mr. Coker says it also has a parachute that would be used, if there should be an emergency. "It starts to work at very low altitude and actually saves both the aircraft and the pilot," he adds. Mr. Coker says the Jetpack will be ready for sale soon.

    Budget Hotels (经济型酒店) in Bloomsbury

    Bloomsbury is one of the most central areas in London. There are many traditional-style small hotels. The hotels listed below are our picks of the best budget hotels in the area.

    Arosfa Hotel

Arosfa Hotel lies on the corner of Torrington Place and Gower St. The Arosfa was once the home of the famous Pre-Raphaelite painter, Sir John Everett Millais. The hotel takes pride in the quality, cleanliness and value that they offer to their guests. For your comfort and safety, smoking inside the hotel is not allowed.

Address: 83 Gower St, London, WC1

    Breakfast: English breakfast

    Internet service: Free WiFi and two personal computers for guests

    George Hotel

The George is a friendly and comfortable smoke-free hotel on a quiet street in North Bloomsbury. All rooms have a work desk and tea/coffee facilities are provided. It's only a 10-minute walk from King's Cross, St Pancras railway station and Euston railway station.

Address: 58-60 Cartwright Gds, London, WC1

    Breakfast: English breakfast

    Internet service: Free WiFi

    Ridgemount Hotel

    The Ridgemount is one of the cheapest hotels in the area. A friendly place and the standard rooms with shared bathrooms are provided for guests. You can speak Welsh or English with the hotel workers. They will be happy to provide useful advice on the area.

Address: 65-67 Gower St, London, WC1

    Breakfast: English breakfast

    Internet service: Free WiFi

    Arran House Hotel

    The Arran House is a popular family-run hotel. It's a little more expensive than the other hotels in the area. Rooms with shared bathrooms are provided.

Address: 77-79 Gower St, London, WC1

    Breakfast: English breakfast

    Internet service: Free WiFi

    Nearly 20 U.S. states have started carrying out former president Barack Obama's Clean Power Plan, which places limits on carbon dioxide emissions from power plants in an effort to reduce the impacts of climate change. The plan has been in legal limbo (边缘) for the past year. Yet scientists have now calculated another outcome of the policy: harm to crop yields (产量) if the plan is cancelled. Along with carbon pollution, coal-fired power plants spew (喷出) pollutants that form what we know as smog. The contribution of smog to increased rates of asthma (哮喘) and premature deaths was already known. The new research estimates the extent to which smog, under air-pollution policies-4n place before the Clean Power Plan, would limit production in 2020 of four major crops: corn, cotton, potatoes and soybeans.

    Led by environmental engineer Shannon L. Capps, now at Drexel University, the team also sketched the extent to which those crop production losses would reduce under three nationwide scenarios (方案). One improved the efficiency of individual power plants. Another modeled a policy similar to the Obama plan, setting state CO₂ emissions goals for the electricity department. A third established a tax on carbon emissions, under which emissions fell the most. But the greatest drop in smog-forming pollutants—and greatest gains in crop yields—came from policies such as the Clean Power Plan.

    Researchers calculated how well each scenario would reduce the potential productivity loss (PPL) of each crop. PPL is a projected value for 2020 and indicates how much crop growth would suffer because of smog. Scenario 2 most closely agrees with results expected from the Clean Power Plan.

    In the mid-1990s, Tom Bissell taught English as a volunteer in Uzbekistan. He left after seven months, physically broken and having lost his mind. A few years later, still attracted to the country, he returned to Uzbekistan to write an article about the disappearance of the Aral Sea.

    His visit, however, ended up involving a lot more than that. Hence this book, Chasing the Sea: Lost Among the Ghosts of Empire in Central Asia, which talks about a road trip from Tashkent to Karakalpakstan, where millions of lives have been destroyed by the slow drying up of the sea. It is the story of an American travelling to a strange land, and of the people he meets on his way: Rustam, his translator, a lovely 24-year-old who picked up his colorful English in California, Oleg and Natasha, his hosts in Tashkent, and a string of foreign aid workers.

    This is a quick look at life in Uzbekistan, made of friendliness and warmth, but also its darker side of society. In Samarkand, Mr Bissell admires the architectural wonders, while on his way to Bukhara he gets a taste of police methods when suspected of drug dealing. In Ferghana, he attends a mountain funeral(葬礼)followed by a strange drinking party. And in Karakalpakstan, he is saddened by the dust storms, diseases and fishing boats stuck miles from the sea.

    Mr Bissell skillfully organizes historical insights and cultural references, making his tale a well-rounded picture of Uzbekistan, seen from Western eyes. His judgment and references are decidedly American, as well as his delicate stomach. As the author explains, this is neither a travel nor a history book, or even a piece of reportage. Whatever it is, the result is a fine and vivid description of the purest of Central Asian traditions.