When Kate's paintings were on show in London，a poet described her paintings as “a ribbon (丝带）around a bomb”．Such comments seem to suggest Kate had a big influence on the art world of her time．Sadly，she is actually a much bigger name today than she was during her time．

    Born in 1907 in a village near Mexico City，Kate suffered from polio（小儿麻痹症）at the age of seven．Her spine (脊柱)became bent as she grew older．Then，in 1925，her back was broken in several places in a school-bus accident．Throughout the rest of her life，the artist had many operations，but nothing was able to cure the terrible pain in her back．However，the accident had an unexpected side effect．While lying in her bed recovering，Kate taught herself to paint．

    In 1929，she got married to Diego Rivera，another famous Mexican artist．Rivera's strong influences on Kate's style can be seen in her early works，but her later works from the 1940s，known today as her best works，show less influence from her husband．

    Unfortunately，her works did not attract much attention in the 1930s and1940s，even in her home country．Her first one-woman show in Mexico was not held until 1953．For more than a decade after her death in 1954，Kate's works remained largely unnoticed by the world，but in the 1970s her works began to gain international fame at last．

Yawning（哈欠）sends out certain messages—either “Oh, this movie is boring" or "I probably need to get some sleep". But did you know that a yawn can also help your brain to cool down when it is so overheated?

    A new study, led by a research team of Princeton University, has indicated（表明）that yawning could be the brain's natural way of regulating temperature. People yawn more often when the temperature outdoors is lower than their body temperature but are less likely to yawn when it is hotter outdoors, according to Sciencedaily.com.

    The research team did an experiment on 160 people, 80 in summer and 80 in winter, to examine how often they yawned at different air temperatures. The study found that people yawned more often in winter than in summer. Scientists say that when the air temperature is lower outside the body, there is heat exchange between the overheated brain and the cool air. But when the air temperature is higher than or equal to the body, people are less likely to yawn because the hot air they breathe in will make the brain even hotter.

    When people yawn, their jaw is also stretched, which increases blood flow and may also help cool the brain.

    The study showed that the amount someone yawned could be related to the amount of time they spent outside. The longer they spent outside in summer, the less they yawn. Nearly 40 percent of participants yawned within their first five minutes outside, but after that the percentage was reduced to less than 10 percent.

    However, the result was the opposite in winter. The number of people who yawned increased when they spent more than five minutes outdoors. But the change was only slight compared to summertime.

    According to Gallup, this is the first report to show that yawning frequencies(频率) change depending on season. This could help us to understand better the way our brains work. It may also help us understand the reason why frequent yawning can sometimes be a sign of brain disease.

    Having a job is great, I have learned. It means I can afford things such as a place to live and daily meals. And with an above-average job, I can afford a car and occasional overseas vacations.

    However, I also understand how difficult it is to have a below-average job, having had many of them before. It's frankly pretty awful. Owning a car was out of the question – I could barely afford to ride the subway.

    So, I decided to go to university and get a degree.

    Later, I emailed my details to every company and government institution with an online careers page. I even printed my resume and handed it out in what seemed like hundreds of office buildings.

    One summer during university, my cousin and I helped out at my uncle's business, fixing roofs, although the only thing I got out of that was back problems.

    That same year, I got a job at a plumbing(管道工程) company, which I was terrible at. It was no surprise when I was asked to leave that job after only four days.

    A lot of people today believe the problem of unemployment in my generation is our fault. Some accuse us of being lazy or feeling too entitled(有资格的). At the same time, some people accuse members of my generation of having a sense of “specialness” that has led us to believe we can all be astronauts, movie stars or singers if we put our minds to it. Also, a few of them think that we would all be happily employed if we would only learn trades or become software engineers, because those people make the most money.

    I realize that not everyone can go into space, star in Hollywood movies or fill stadiums with fans, however. I also think not everyone can make a good electrician or design advanced computer software – I know I can't. Everyone is good at something, but no one is good at everything. It took me hundreds of rejection emails to realize that I had to focus on finding a job where I could actually be successful.

    And now, I finally have that job. All it took was several years of desperation, failure and an honest assessment(评估) of my personal value in the job market.

    It's not the best start, but it's not bad for a start too.

    You know the feeling that you have left your phone at home and feel anxious, as if you have lost your connection to the world. “Nomophobia” (无手机恐惧症) affects teenagers and adults alike. You can even do an online test to see if you have it. Last week, researchers from Hong Kong warned that nomophobia is infecting everyone. Their study found that people who use their phones to store, share and access personal memories suffer most. When users were asked to describe how they felt about their phones, words such as “hurt” (neck pain was often reported) and “alone” predicted higher levels of nomophobia.

    “The findings of our study suggest that users regard smartphones as their extended selves and get attached to the devices,” said Dr. Kim Ki Joon. “People experience feelings of anxiety and unpleasantness when separated from their phones.” Meanwhile, an American study shows that smartphone separation can lead to an increase in heart rate and blood pressure.

    So can being without your phone really give you separation anxiety? Professor Mark Griffiths, psychologist and director of the International Gaming Research Unit at Nottingham Trent University, says it is what is on the phone that counts-the social networking that creates Fomo (fear of missing out).

    “We are talking about an internet-connected device that allows people to deal with lots of aspects of their lives,” says Griffiths. “You would have to surgically remove a phone from a teenager because their whole life is rooted in this device.”

Griffiths thinks attachment theory, where we develop emotional dependency on the phone because it holds details of our lives, is a small part of nomophobia. For “screenagers”, it is Fomo that creates the most separation anxiety. If they can't see what's happening on Snapchat or Instagram, they become panic-stricken about not knowing what's going on socially. “But they adapt very quickly if you take them on holiday and there's no internet,” says Griffiths.

    A few weeks ago, I called an Uber to take me to the Boston airport for a flight home for the holidays. As I slid into the back seat of the car, the warm intonations(语调) of the driver's accent washed over me in a familiar way.

    I learned that he was a recent West African immigrant with a few young children, working hard to provide for his family. I could relate: I am the daughter of two Ethiopian immigrants who made their share of sacrifices to ensure my success. I told him I was on a college break and headed home to visit my parents. That's how he found out I went to Harvard. An approving eye glinted at me in the rearview window, and quickly, we crossed the boundaries of rider and driver. I became his daughter, all grown up—the product of his sacrifice.

    And then came the fateful question: "What do you study?" I answered "history and literature" and the pride in his voice faded, as I knew it might. I didn't even get to add "and African-American studies" before he cut in, his voice thick with disappointment, "All that work to get into Harvard, and you study history?"

    Here I was, his daughter, wasting the biggest opportunity of her life. He went on to deliver the age-old lecture that all immigrant kids know. We are to become doctors (or lawyers, if our parents are being generous)—to make money and send money back home. The unspoken demand, made across generations, which my Uber driver laid out plainly, is simple: Fulfill your role in the narrative(故事) of upward mobility so your children can do the same.

    I used to feel anxious and backed into a corner by the questioning, but now as a junior in college, I'm grateful for their support more than anything. This holiday season, I've promised myself I won't get annoyed at their inquiries. I won't defensively respond with "but I plan to go to law school!" when I get unrequested advice. I'll just smile and nod, and enjoy the warmth of the occasion.

"Assume you are wrong." The advice came from Brian Nosek, a psychology professor, who was offering a strategy for pursuing better science.

To understand the context for Nosek's advice, we need to take a step back to the nature of science itself. You see despite what many of us learned in elementary school, there is no single scientific method. Just as scientific theories become elaborated and change, so do scientific methods.

But methodological reform hasn't come without some fretting and friction. Nasty things have been said by and about methodological reformers. Few people like having the value of their life's work called into question. On the other side, few people are good at voicing criticisms in kind and constructive ways. So, part of the challenge is figuring out how to bake critical self-reflection into the culture of science itself, so it unfolds as a welcome and integrated part of the process, and not an embarrassing sideshow.

What Nosek recommended was a strategy for changing the way we offer and respond to critique. Assuming you are right might be a motivating force, sustaining the enormous effort that conducting scientific work requires. But it also makes it easy to interpret criticisms as personal attacks. Beginning, instead, from the assumption you are wrong, a criticism is easier to interpret as a constructive suggestion for how to be less wrong—a goal that your critic presumably shares.

One worry about this approach is that it could be demoralizing for scientists. Striving to be less wrong might be a less effective motivation than the promise of being right. Another concern is that a strategy that works well within science could backfire when it comes to communicating science with the public. Without an appreciation for how science works, it's easy to take uncertainty or disagreements as marks against science, when in fact they reflect some of the very features of science that make it our best approach to reaching reliable conclusions about the world. Science is reliable because it responds to evidence: as the quantity and quality of our evidence improves, our theories can and should change, too.

Despite these worries, I like Nosek's suggestion because it builds in cognitive humility along with a sense that we can do better. It also builds in a sense of community—we're all in the same boat when it comes to falling short of getting things right.

Unfortunately, this still leaves us with an untested hypothesis （假说）: that assuming one is wrong can change community norms for the better, and ultimately support better science and even, perhaps, better decisions in life. I don't know if that's true. In fact, I should probably assume that it's wrong. But with the benefit of the scientific community and our best methodological tools, I hope we can get it less wrong, together.