Exercise may help to safeguard the mind against depression through previously unknown effects on working muscles, according to a new study involving mice.

    Mental health experts have long been aware that even mild, repeated stress can contribute to the development of depression and other mood disorders in animals and people. Scientists have also known that exercise seems to cushion against depression. But precisely how exercise, a physical activity can lessen someone's risk for depression, a mood state, has been mysterious. So for the new study, researchers at the Karolinska Institute in Stockholm studied the brains and behavior of mice in a complicated and novel fashion.

    We can't ask mice if they are feeling cheerful or in low spirits. Instead, researchers have pictured certain behaviors that indicate depression in mice. If animals lose weight, stop seeking out a sugar solution when it's available — because, probably, they no longer experience normal pleasures — or give up trying to escape from the cold-water zone just freeze in place, they are categorized as depressed. And in the new experiment, after five weeks of frequent but low-level stress, such as being lightly shocked, mice displayed exactly those behaviors. They became depressed.

    The scientists could then have tested whether exercise blunts (延缓) the risk of developing depression after stress by having mice run first. But, frankly, from earlier research, they wanted to know how, so they bred pre-exercised mice. A wealth of earlier research by these scientists and others had shown that aerobic exercise, in both mice and people, increases the production within muscles of an enzyme (酶) called PGC-1alpha. The Karolinska scientists suspected that this enzyme somehow creates conditions within the body that protect the brain against depression. Then, the scientists exposed the animals, which without exercising, were in high levels of PGC-1alpha to five weeks of mild stress. The mice responded with slight symptoms of worry. But they did not develop depression. They continued to seek out sugar and fought to get out of the cold-water zone. Their high levels of PGC-1alpha appeared to make them depression-resistant. Finally, to ensure that these findings are relevant to people, the researchers had a group of adult volunteers complete three weeks of frequent endurance training, consisting of 40 to 50 minutes of moderate cycling or jogging. The scientists conducted muscle biopsies (活体检查) before and after the program and found that by the end of the three weeks, the volunteers' muscle cells contained substantially more PGC-1alpha than at the study's start. The finding of these results, in the simplest terms, is that “you reduce the risk of getting depression when you exercise,” said Maria Lindskog, a researcher at the Karolinska Institute.

    Ever wondered whether punishment actually makes people cooperate (合作)? A team of scientists created an experiment to figure it out and the results were pretty unexpected.

    To understand what they found, you have to know why these scientists were studying punishment. They were trying to figure out why people cooperate when it's often so easy to profit at others expense. Why don't friends steal from each other? Why do parents bother to feed their children? If the answer to these questions is obvious to you, congratulations, you are ahead of scientists. They're still trying to figure it out.

    In this experiment, researchers had 225 Chinese students play a game, where if the students cooperated, they'd all get a number of points. But if one defected (变节) and everyone else cooperated, the defector would get a lot of points, and the cooperators would lose out. This game represents a lot of real life situations where you struggle with a decision: work together and do OK, or run off with the rewards, ruining everybody else's day.

    This is actually a pretty ordinary economic experiment. But the researchers added two changes to see if they could mimic(糢拟)the real world better. Change one: some students played many rounds together, so they'd learn who they could trust. Change two: people could punish each other, sacrificing a point or two to destroy another player's score.

    In the end, the researchers found that playing multiple rounds made people cooperate more, which definitely mimics human society. But the whole punishment thing led to a surprise: punishing didn't actually make people cooperate more. In fact, it made them cooperate less.

    So the scientists still don't know why people cooperate, though it looks like it has more to do with groups sticking together than it does with punishment.

    Tim Richter and his wife, Linda, had taught for over 30 years near Buffalo, New York – he in computers, she in special education. "Teaching means everything to us," Tim would say. In April 1998, he learned he would need a heart operation. It was the kind of news that leads to some serious thinking about life's purpose.

    Not long after the surgery, Tim saw a brochure describing Imagination Library, a program started by Dolly Parton's foundation (基金会) that mailed a book every month to children from birth to age five in the singer's hometown of Sevier, Tennessee. "I thought, maybe Linda and I could do something like this when we retire," Tim recalls. He placed the brochure on his desk, "as a reminder."

    Five years later, now retired and with that brochure still on the desk, Tim clicked on imaginationlibrary.com. The program had been opened up to partners who could take advantage of book and postage discounts.

    The quality of the books was of great concern to the Richters. Rather than sign up online, they went to Dollywood for a look-see. "We didn't want to give the children rubbish," says Linda. The books – reviewed each year by teachers, literacy specialists and Dollywood board members – included classics such as Ezra Jack Keats's The Snowy Day and newer books like Anna Dewdney's Llama Llamaseries.

    Satisfied, the couple set up the Richter Family Foundation and got to work. Since 2004, they have shipped more than 12,200 books to preschoolers in their area. Megan Williams, a mother of four, is more than grateful: "This program introduces us to books I've never heard of."

    The Richters spend about ＄400 a month sending books to 200 children. "Some people sit there and wait to die," says Tim. "Others get as busy as they can in the time they have left."

    A couple from Miami, Bill and Simone Butler, spent sixty-six days in a life raft (救生艇)in the seas of Central America after their boat sank.

    Twenty-one days after they left Panama in their boat, in Simony, they met some whales (鲸). "They started to hit the side of the boat," said Bill, "and then suddenly we heard water." Two minutes later, the boat was sinking. They jumped into the life raft and watched the boat go under the water.

    For twenty days they had tins of food, biscuits, and bottles of water. They also had a fishing line and a machine to make salt water into drinking water—two things which saved their lives. They caught eight to ten fish a day and ate them raw(生的).Then the line broke. "So we had no more fish until something very strange happened. Some sharks(鲨鱼) came to feed, and the fish under the raft were afraid and came to the surface. I caught them with my hands."

    About twenty ships passed them, but no one saw them. After fifty days at sea their life raft was beginning to break up. Then suddenly it was all over. A fishing boat saw them and picked them up. They couldn't stand up. So the captain carried them onto his boat and took them to Costa Rica. Their two months at sea was over.

    Visit one of the most outstanding prehistoric sites in the United Kingdom, and enjoy amazing historic English attractions. Please notice that every tour starts and ends in London. Have a tour with visiting Britain.

Stonehenge Direct Tour

    Visit one of the most outstanding prehistoric sites in England and in the world: Stonehenge.

    Duration: 1 day

    Price: Adults ￡29.99, Children ￡28.99

Stonehenge and Bath Tour

    Enjoy a late breakfast before heading to the Stonehenge site and end your day with an original visit to the Roman Baths.

    Duration: 10 hours (departure 10:30 a. m., return 8:30 p. m.)

    Price: Adults ￡64, Children ￡60

Stonehenge, Bath and Windsor Castle Tour

    Explore three of England's most popular sites to visit: Windsor Castle, Stonehenge and the Roman Baths.

    Duration: 1 day (return 8:30 p. m.)

    Price: Adults ￡64.80, Children ￡61.20

Stonehenge, Lacock and Bath Tour

    Come and feel the warmth of Bath, see the pleasant village of Lacock, and solve the mystery of Stonehenge.

    Duration: 1 day (return 6 p.m.)

    Price: Adults ￡85, Children ￡78

Stonehenge, Windsor and Oxford Tour

    Choose Stonehenge, Windsor and Oxford Tour and enjoy ancient mysticism, royal history and illustrious knowledge.

    Duration: 1 day

    Price: Adults ￡72, Children ￡68

Stonehenge, Bath and Stratford Tour

    Take a tour to make the most of the English historic attractions: the Stonehenge site, Bath and Stratford, the birthplace of playwright William Shakespeare.

    Duration: 1 day (return 8 p. m.)

    Price:Adults ￡79, Children ￡68

    Reducing plastic waste isn't easy because the cheap material is found in almost every household item. Now, a delicious and nutritious solution has come up to help reduce our dependence on this environmental hazard.

    David Christian, the co-founder of Evoware, says the idea of creating the biodegradable (生物降解的) products came from concern at the country's high pollution rate. Indonesia is home to four of the world's worst polluted rivers. Since single-use packaging is a large contributor to the problem, Evoware decided to deal with that first.

    After investigating various materials, the company settled on seaweed. Unlike corn, commonly used for biodegradable containers, seaweed does not require resources like water or large amounts of space. Since Indonesian farmers already harvest more seaweed than they can sell, it's easy for the company to find the material.

    Though they will not reveal their production process, Evoware says the seaweed packaging contains no chemicals and is safe to consume. The company has also invented single-use cups, which can break down 30 days after they're thrown away.

    While replacing plastic with the seaweed products may seem appealing to most of us, it is a hard-sell in Indonesia. According to Christian, "The awareness to reduce single-use plastic is still very low. This makes our bioplastic unnecessary." Also a factor is the cost, which is higher than using plastic. Hopefully, Evoware will succeed in convincing Indonesians and people worldwide that switching to their products will be helpful to protecting our beautiful planet.