【推荐2】Could being a little overweight help you live longer? A new international analysis (分析) shows a surprising answer: while obesity (肥胖) increases the risk of dying early, being slightly overweight reduces it. These studies included almost 3 million adults from around the world, yet the results were clearly the same, the authors of the analysis said.

“If you have a medical condition, your chances, of living are slightly better if you are a bit on the heavy side,” says study author Katherine Flegal, “Several factors may contribute to this finding.”

“Heavier people may tend to see the doctor earlier,” she says, “and may be more likely to be treated according to the doctor’s advice. Obesity itself may protect the heart, or someone who is heavier might be better able to fight against a shock to the system.”

For the study, Flegal’s team collected data on more than 2.88 million people included in 97 studies. The researchers looked at the participants’ body mass index (BMI), a measure of body fat that takes into consideration a person’s height and weight.

The researchers found that, compared with people of normal weight, overweight people had a 6 percent lower risk of death. Obese people, however, had an 18 percent higher risk. For those who were the least obese, the risk of death was 5 percent lower than people of normal weight, but for those who were the most obese, the risk of death was 29 percent higher, the findings showed.

While the study found a relation between weight and the risk of early death, it did not prove a cause-and-effect relationship. Indeed, one expert warned that body weight alone cannot tell health and the risk of death.

“There are other factors that play a role in health,” says Dr. William, a professor at Louisiana State University. “BMI simply is a parameter (参数); it doesn’t take family history, smoking, fitness, and other factors into consideration.”

【推荐1】Food acts as a form of communication in two fundamental ways. Sharing bread or other foods is a common human tradition that can promote unity and trust. Food can also have a specific meaning, and play a significant role in a family or culture’s celebrations or traditions. The foods we eat—and when and how we eat them—are often unique to a particular culture or may even differ between rural and urban areas within one country.

Sharing bread, whether during a special occasion or at the family dinner table, is a common symbol of togetherness. Many cultures also celebrate birthdays and marriages with cakes that are cut and shared among the guests. Early forms of cake were simply a kind of bread, so this tradition has its roots in the custom of sharing bread.

   Food also plays an important role in many New Year celebrations. In the southern United States, pieces of corn bread represent blocks of gold for prosperity (兴旺) in the New Year. In Greece, people share a special cake called vasilopita. A coin is put into the cake, which signifies success in the New Year for the person who receives it.

Many cultures have ceremonies to celebrate the birth of a child, and food can play a significant role. In China, when a baby is one month old, families name and welcome their child in a celebration that includes giving red-colored eggs to guests. In many cultures, round foods such as grapes, bread, and mooncakes are eaten at welcome celebrations to represent family unity.

Nutrition is necessary for life, so it is not surprising that food is such an important part of different cultures around the world.

【推荐2】Elena Yi dreamed of pursuing piano performance in college, never minding that her fingers could barely reach the length of an octave (八度音阶). Unable to fully play many works by Romantic-era composers including Beethoven and Brahms, she tried anyway— and in her determination to spend hours practicing a Chopin concerto, wound up injuring herself.

The efforts of Professor Carol Leone   from the   Southern Methodist University (SMU) are changing all that: twenty years ago, the school became the first major university in the U.S. to introduce smaller keyboards into its music program, leveling the playing field for Yi and other piano majors.

Yi, 21, tried one of the smaller keyboards, “I remember being really excited, because my hands could actually reach and play all the right notes,” she said.

For decades, few questioned the size of the traditional piano. For those with small hand spans (掌距), it’s difficult to properly play many works of Beethoven and Brahms. Those who attempt to play them either get used to skipping notes or risk injury with repeated play. Leone is familiar with such challenges. Born into a family of musicians, she favored classical music and pursued piano despite her small hand span, and earned a degree as a doctor in musical arts.

The idea of smaller keyboards first met resistance from some traditionalists. Leone also said that when she raised the issue with one Viennese professor, he told her there were already too many pianists anyway.

Though such resistance is fading, there are some very traditional people who think of piano as a competitive thing. Leone said, “This is art, not sport. It’s about making as much beautiful art as possible, and we should give everybody the opportunity to do that.”

【推荐1】“Have a nice day!” may be a pleasant gesture or a meaningless expression. When my friend Maxie says “Have a nice day” with a smile, I know she sincerely cares about what happens to me. I feel loved and secure since another person cares about me and wishes me well.

“Have a nice day. Next!” This version of the expression is spoken by a salesgirl at the supermarket who is rushing me and my groceries out the door. The words come out in the same   tone(腔调) with a fixed procedure (步骤). They are spoken at me, not to me. Obviously, the concern for my day and everyone else’s is the management’s attempt to increase business.

The expression is one of those behaviors that help people get along with each other. Sometimes it shows the end of a meeting. As soon as you hear it, you know the meeting is at an end. Sometimes the expression saves us when we don't know what to say. “Oh, you may have a tooth out? I'm terribly sorry, but have a nice day.”

The expression can be pleasant. If a stranger says “Have a nice day” to you, you may find it heart-warming because someone you don't know has tried to be nice to you.

Although the use of the expression is an insincere, meaningless social custom at times, there is nothing wrong with the sentence except that it is a little uninteresting. The salesgirl, the waitress, the teacher, and all the countless others who speak it without thinking may not really care about my day. But in a strange and comfortable way, it's nice to know they care enough to pretend they care when they really don't care all that much. While the expression may not often be sincere, it is always spoken. The point is that people say it all the time when they like.

【推荐2】It is every kid’s worst nightmare(噩梦) and six-year-old Jaden Hayes has lived it twice. First he lost his dad when he was only at the age of four and then last month his mom died unexpectedly in her deep sleep.

“I tried and I tried and I tried to get her awake , but... I just couldn’t,” said Jaden.

No one could imagine how heartbroken Jaden was.

But there’s another side to his sadness. A side he first made public a few weeks ago when he told his aunt, Barbara DiCola, and now his guardian(监护人) after both his parents died, that he was sick and tired of seeing everyone sad all the time. And he had a plan to fix it.

“And that was the beginning of it,” said Barbara. “That’s where the adventure began.”

Jaden asked his aunt Barbara to buy a bunch of little toys and bring him to downtown Savannah, Georgia near where he lives, so he could give them away to anyone who will smile to him. “I’m trying to make people smile,” said Jaden.

Jaden targets people who aren’t already smiling and then turns their day around. He’s gone out on four different occasions now and he is always successful. Even if sometimes he doesn’t get exactly the reaction he was hoping for.

It is just so overwhelming to some people that a six-year-old orphan would give away a toy — expecting nothing in return — except a smile.

“I’m depending on it to be 33,000,” said Jaden. When asked if he thinks he can make that goal, he answered: “I think I can.”

【推荐3】Coffee is an important part of Italian culture and since arriving here over six months ago, I have drunk a lot of it!

Of course, coffee is also very popular in the UK but coffee culture in Italy is a completely different story. In Italy, when you order a coffee in a café or bar ( 酒吧), you are served with a tiny, bitter espresso. This is“normal (正常的) coffee” for Italians and they are not so interested in the huge coffees that we drink in the UK. If you want more than one sip (小口) of coffee in Italy, lungo is a good choice. It is espresso with a little more water added, but still served in a small cup. In addition, while takeaway coffee is quite popular among Brits, it is not very common at all in Italy, especially in non-touristy areas. Generally, Italians prefer to drink their tiny coffees while standing at the bar and, for many, this short break is an important part of their day.

Usually, breakfast in a bar in Italy includes a coffee and a pastry (酥皮糕点). I have been spoiled for choice with lovely cafés in the Italian town I'm living in. These cafés sell different kinds of mouth-watering pastries - either plain (无馅料的) or filled with cream, chocolate, etc - as well as delicious coffee. Cappuccinos are very popular at breakfast time and, for me, a creamy cappuccino and a pastry with chocolate is the perfect way to start the day.

Finally, I have found that coffee in Italy is so much cheaper than coffee in the UK. Normally, an espresso or a macchiato (an espresso with a drop of milk) costs around a euro and a cappuccino about €1.50! They are small, of course, but this means that in Italy it is possible to go out for coffee every day without breaking the bank.

【推荐1】Summer brings flowers and dirt and barbeque smoke. In the most wintery places, there isn’t much outside on cold days except snow, strong wind and cars warming up. Pine needles, wood smoke and snow---these are the smells of winter, and for people who live with different seasons, wintry weather brings its own set of olfactory(嗅觉的) experiences. But why does the cold of winter smell different from the heat of summer?

One reason is that odor (气味) molecules move much more slowly as the air temperature drops, said Pamela Dalton, an olfactory scientist at the Monell Chemical Senses Center in Philadelphia. That means that there are simply fewer smells to smell on a cold, crisp day than there are on a hot and humid one. It’s the same reason why hot soup smells more than cold soup does and why the garbage truck leaves behind the strongest smells on steamy summer days.

What’s more, our noses don’t work quite well when the surrounding air is cold, Dalton said. In experiments that require biopsies(活组织检查) of olfactory receptors that lie deep inside the nose, researchers at Monell have discovered that the receptors “bury themselves a little more deeply in the nose in winter,” she said, “possibly as a protective response against cold, dry air.”

There is a strong psychological factor in our sense of smell, Hirsch added, and what we expect to smell has a big influence on what we actually smell. In The Invalid’s Story by Mark Twain, for example, a man is stuck on a train next to what he thinks is a rotting dead body but is actually a box of cheese that smells extremely unpleasant. So strongly affected by the smell, he spends too long looking for fresh air on the freezing platform and develops a fever that ends up killing him. “What you think of a smell have powerful effects on you whether you like it and whatever you think it to be,” Hirsch said. “So, if you go outside in winter and you are used to smelling snow or nuts in the fire or whatever you happen to smell outside, that’s what you will interpret smells to be.”

To cope with lack of smells in winter, many people try to burn more candles with pleasant smell, cook more sweet stews(炖菜) and bake more cookies, which creates a greater contrast between the indoor and outdoor environments. “You’re probably fond of indoor smells in the winter,” Dalton said. “Homes are closed up, and windows are closed. We concentrate on the smells of cooking and living.”

【推荐2】How to Make Friends, According to Science

Friendship is one of life’s most important features, and one too often taken for granted.

The human desire for companionship may feel boundless, but research suggests that our social capital is finite—we can only handle a certain number of relationships at one time. Social scientists have used some creative approaches to measure the size of people’s social networks; these have returned estimates ranging from about 250 to about 5,500 people. Looking more specifically at friendship, a study using the exchange of Christmas cards to test closeness put the average person’s friend group at about 121 people. However vast our networks may be, our inner circle tends to be much smaller. The average American trusts only 10 to 20 people. Moreover, that number may be shrinking: From 1998 to 2017, the average number of trusted friends decreased from three to two. This is both sad and of important consequence, because people who have strong social relationships tend to live longer than those who don’t.

So what should you do if your social life is lacking? Here the research is instructive. To begin with, don’t refuse to consider the humble acquaintance（交情）. Even interacting with people with whom one has weak social ties has a meaningful influence on well-being. Beyond that, building deeper friendships may be largely a matter of putting in time. A recent study out of the University of Kansas found that it takes about 50 hours of socializing to go from acquaintance to casual friend, an additional 40 hours to become a “real” friend, and a total of 200 hours to become a close friend.

If that sounds like too much effort, renewing inactive social ties can be especially rewarding. Reconnected friends can quickly recapture the trust they previously built, while offering each other a dash of novelty（新奇）drawn from whatever they’ve been up to in the meantime. And if all else fails, you could start randomly to tell secrets to people you don’t know that well. Self-disclosure makes us more likable, and as a bonus, we are more likely to favor those to whom we have revealed our soul.

Longing for closeness and connection is common and everywhere, which suggests that most of us are stumbling（跌跌撞撞）through the world, expecting companionship that could be easily provided by the lonesome stumblers all around us. So set aside this article, turn to someone nearby, and try to make a friend.

【推荐3】As Artificial Intelligence(AI) becomes increasingly sophisticated, there are growing concerns that robots could become a threat. This danger can be avoided, according to computer science professor Stuart Russell, if we figure out how to turn human values into a programmable code.

Russell argues that as robots take on more complicated tasks, it’s necessary to translate our morals into AI language.

For example, if a robot does chores around the house, you wouldn’t want it to put the pet cat in the oven to make dinner for the hungry children. “You would want that robot preloaded with a good set of values, ” said Russell.

Some robots are already programmed with basic human values. For example, mobile robots have been programmed to keep a comfortable distance from humans. Obviously there are cultural differences, but if you were talking to another person and they came up close in your personal space, you wouldn’t think that’s the kind of thing a properly brought-up person would do.

It will be possible to create more sophisticated moral machines, if only we can find a way to set out human values as clear rules.

Robots could also learn values from drawing patterns from large sets of data on human behavior. They are dangerous only if programmers are careless.

The biggest concern with robots going against human values is that human beings fail to so sufficiently test and they’ve produced a system that will break some kind of taboo.

One simple check would be to program a robot to check the correct course of action with a human when presented with an unusual situation.

If the robot is unsure whether an animal is suitable for the microwave, it has the opportunity to stop, send out beeps, and ask for directions from a human. If we humans aren’t quite sure about a decision, we go and ask somebody else.

The most difficult step in programming values will be deciding exactly what we believe in moral, and how to create a set of ethical rules. But if we come up with an answer, robots could be good for humanity.