Do you often feel lonely? What do you do when you feel that way? Hide yourself away and spend your time reading, watching TV or walking around?

You might think that feeling lonely is just like feeling happy, sad or scared — that it's just one of your various moods. That is true. However, if you let yourself be lonely for too long without dealing with it, you could be making a serious mistake.

    Doctors have known for some time that feeling lonely is bad for the mind. It can lead to mental health problems such as depression, stress and reduce confidence. “Being lonely means not feeling connected or cared for, but it's not about being mentally alone,” Lisa Jaremka, scientist from Ohio State University, US, told Live Science in January. And there's growing evidence that not having friends is connected with physical illness as well.

    In 2006, for example, scientists studied 2,800 women who had cancer. They found that those who had few friends or family were five times more likely to die of their disease than women with many social contacts. Also, even healthy people had a better chance of falling ill if they felt left out by others, according to the BBC.

    The results have scientists thinking that loneliness might hurt the immune system(免疫系统), which protects the body from diseases.

    Hoping to prove this theory, Jaremka and her research team put volunteers(志愿者) through a stress test. During the test, volunteers were asked to make an unprepared speech in front of a group of stony-faced people. The researchers found that volunteers who said they were lonely in their daily lives felt more stress during the test. And their blood samples showed that all the stress had managed to cause harmful changes to their immune system.

     “Loneliness has been thought of in many ways as a chronic stressor(慢性增压器) — a socially painful situation that can last for quite a long time, ” explained Jaremka, who led the study.

    The number of people suffering from loneliness is increasing all over the world. However, solving the problem is easier said than done. It won't work to just “tell anyone to go out and find someone to love you”, said Jaremka. “We need to create support networks.”

    On the last day before Christmas, I hurried to the supermarket to buy Christmas gifts. In the supermarket, I noticed a little boy, holding a doll and looking so sad. He turned to the old woman next to him, “Granny, are you sure I don't have enough money?” The old lady replied, “You know we don't have enough money to buy this doll, my dear.” Then she left for something else and the boy still stood there.

    Finally, I went to the boy and asked him who he wanted to give this doll to. “It is the doll that my sister wanted so much for this Christmas. She was so sure that Father Christmas would bring it to her.”

    I told him that maybe Father Christmas will bring it to her. But he replied to me sadly, “No, Father Christmas cannot bring it to her where she is now. I have to give the doll to my mother so that she can give it to her when she goes there. My sister has gone to be with God. Daddy says that Mummy will also go to see God very soon, so I thought that she could bring the doll with her to give it to my sister.”

    Hearing this, I quickly reached into my wallet and took a few notes and said to the boy, “What if we checked again, just in case if you have enough money?”

    “OK,” he said, “I hope that I have enough.”

    I added some of my money to his without his seeing and we started to count it. There was enough for the doll.

    The little boy said, “Thank God for giving me enough money.”

    Then he looked at me and added, “I prayed to God yesterday before I slept to make sure I have enough money to buy this doll. He heard me.”

    When the fork was stolen off Bart Michiels's mountain bike last summer, he wheeled it nearly three miles from his home in Chelsea to Frank's Bike Shop on the eastern end of Grand Street.

Mr. Michiels passed many other bike shops along the way, including one that offers free coffee. But for 20 years, he has remained devoted(忠实的) to Frank's. “Frank's the man,” he said of Frank Arroyo, the owner. “I don't care where he is in the city — I'll go.”

    Mr. Michiels doesn't have to worry about Mr. Arroyo's relocating (搬迁). The shop has stayed on the Lower East Side of Manhattan for 40 years.

    After Mr. Michiels left, Marvin Priess arrived. A professor of chemistry and math, Mr. Priess wheeled in the Ross 18-speed he had bought at Frank's in 1978 and still rides today, at age 68. Mr. Priess said that over the years, every single part of it that couldn't be repaired had been replaced, sometimes more than once, at Frank's. Customers don't come for the ambience(环境). It's crowded and dirty; buckets of parts and boxes of training wheels line the entryway.

    The store is filled with about 500 bikes and you will find Mr. Arroyo, 72, six days a week. He has been in the bike business since age 14. Born and raised on the Lower East Side, he has employed and taught many young people in the neighborhood. He is also willing to repair bikes in any condition, as well as his neighbors' walkers and wheelchairs.

    English Epps, a lawyer, needed a new seat; his had been stolen. “I've been coming here since I was in the third grade,” he said, adding: “There's a new bike shop on Delancey Street, but everybody comes here.”

    Who cares if people think wrongly that the Internet has had more important influences than the washing machine? Why does it matter that people are more impressed by the most recent changes?

    It would not matter if these misjudgments were just a matter of people's opinions. However, they have real impacts, as they result in misguided use of scarce resources.

    The fascination with the ICT (Information and Communication Technology) revolution, represented by the Internet, has made some rich countries wrongly conclude that making things is so "yesterday" that they should try to live on ideas. This belief in "post-industrial society" has led those countries to neglect their manufacturing sector (制造业) with negative consequences for their economies.

    Even more worryingly, the fascination with the Internet by people in rich countries has moved the international community to worry about the "digital divide" between the rich countries and the poor countries. This has led companies and individuals to donate money to developing countries to buy computer equipment and Internet facilities. The question, however, is whether this is what the developing countries need the most. Perhaps giving money for those less fashionable things such as digging wells, extending electricity networks and making more affordable washing machines would have improved people's lives more than giving every child a laptop computer or setting up Internet centres in rural villages, I am not saying that those things are necessarily more important, but many donators have rushed into fancy programmes without carefully assessing the relative long-term costs and benefits of alternative uses of their money.

    In yet another example, a fascination with the new has led people to believe that the recent changes in the technologies of communications and transportation are so revolutionary that now we live in a "borderless world". As a result, in the last twenty years or so, many people have come to believe that whatever change is happening today is the result of great technological progress, going against which will be like trying to turn the clock back. Believing in such a world, many governments have put an end to some of the very necessary regulations on cross-border flows of capital, labour and goods, with poor results.

    Understanding technological trends is very important for correctly designing economic policies, both at the national and the international levels, and for making the right career choices at the individual level. However, our fascination with the latest, and our under valuation of what has already become common, can, and has, led us in all sorts of wrong directions.

    While faking and fierce looks are among animals great defenses, many species know that everyone runs from a big stink (臭气) too.

    Vulture (秃鸳)

    Vultures, are street sweepers that feast on the rotting flesh of dead animals, which benefits us by ridding our highways and landscapes of animal bodies and the bacteria they might carry. When vultures feel threatened they vomit, and the smell of vomited-on dead bodies puts of most predators. Throwing up allows the vulture to fly away more quickly-and the vomit can hurt the aggressor's eyes and face.

    Opossum (负鼠)

    In some ways opossums have it easy. In order to become "dead", they don't have to fax anyone a death certificate. They just lie there with their tongues hanging out with the smell of dead flesh, sometimes for hours, effectively convincing potential predators they can find a much fresher meal elsewhere. Even if they keep getting attacked, they won't move any more than a human statue until the threat has passed.

    Hoatzin (磨雉)

    Hold your nose and meet the hoatzin, a bird of distinctions, not the least of which is that it smells like fresh cow shit. The animal mostly eats leaves and it's the only bird known to digest by fermentation, like a cow. This process is what causes its smell and has earned it the nickname the "stink bird

    Millipedes (千足虫)

    Millipedes are tricky. For starters they look wormy. Their name is deceptive, too: Their legs number about 750. Their major defense is to curl up into a ball. They, though, also release a harm eyes, and leave a horrible smell on their attackers.

    Sea Hare (海兔)

    The graceful sea hare is plain in taste in the first place, so it's not the most popular dish in the seafood chain. Nonetheless this type of sea creature has a pretty creative smell-related defense that is almost the opposite of its smelly companions on this list. The sea hare gives out a slimy, purple ink, the substance which makes food less palatable to predators.

    Researchers using lobsters (2-f) as model predators found that the sea blocks the lobsters receptive mechanism. In other words, the sea hare gives its attacker the equivalent of a stuffy nose so they don't know how appealing it is.

    Two graduates from Cambridge University in the United Kingdom found themselves about to graduate, yet with loans to pay off. The pair decided to begin a strange, year-long project to battle their debt.

    The men, Ross Harper and Edward Moyse, set up the website BuyMyFace.com last October as a way to get rid of the £50, 000 they shared as student loans. The idea behind the project was to earn money by selling their faces as advertising space every day for a year. Each day, they advertise a different business by painting the brand's name or logo onto their faces and upload the pictures to the homepage of BuyMyFace.com, adding a link to the advertiser's website and including a short piece of text about it. After they paint their faces and publish them on the website, Harper and Moyse go out to highly populated areas such as music festivals and theme parks to maximize their faces' exposure. They hope more people will pay attention to the advertisements on their faces.

    At this time, Harper and Moyse have advertised their faces for over four months without skipping a day and they're more than halfway to their goal. Though they first started charging a minimum of about £1.60 per company, the prices have risen as their popularity increases. For advertising space during the rest of April, they range between £250 and £750. Terri L. Rittenburg, associate professor of marketing at the University of Wyoming, said that she had heard of people tattooing (纹身) logos on themselves before, but this idea is much better. According to her, at first the idea would be new and unusual and attract attention. People are interested in this particular style of advertisement and would like to try what they advertise. But she is unsure how long it would last.

    At least for now, companies that have bought Harper and Moyse's faces have written positive comments on the pair's website. "We had a three percent increase in website traffic on the very day and for two days more afterwards," said one of the companies.