I was selfish as a teenager. I usually spent my time thinking about myself and taking care of my own needs. I let my older brother do most of the work around the house until he left for college. I let my mom and dad worry about our bills and problems while I read books, played, and lost myself in my own imagination. This didn't change even when I went to college either. I studied hard but only to make my own life better. Even when I started to explore my faith, it was only to increase my own happiness.

    I married after graduation and decided to start a family. Of course, I had no idea what hard knocks reality had in store for my selfish soul. Soon I found myself unemployed, deeply in debt, and with a new baby on the way. l found out that life has little sympathy for spoiled people. In fact, all of the struggles I was going through were beating the selfishness slowly out of me.

    Still, I didn't give up on happiness. I knew that there must be a way to find it. I finally realized, however, that it had to include more than just my own needs, wants, and desires. The answer began to make itself clear one night shortly after my baby boy was born. I got a bottle and held him in my arms. As I was feeding him I looked down and saw his big, innocent, trusting eyes. I smiled and talked to him. Then he smiled and I could feel my heart growing, expanding with love. I felt such peace and joy. At that moment I had a hint of the truth: it is by growing our hearts with love that we find our happiness.

    Carolyn Arends wrote: "The more people you let into your heart, the bigger your heart gets. The more love you get, the more love you have to give. It just keeps growing." So, keep loving, keep living and keep caring. Keep growing your heart today, tomorrow, and always.

    A recent study led by researchers from the National University of Singapore (NUS) has found a clear link between the color of a taxi and its accident rate. An analysis of 36 months of detailed taxi, driver and accident data from two fleets of yellow and blue taxis in Singapore suggested that yellow taxis have fewer accidents than blue taxis. The higher visibility (能见度)of yellow makes it easier for drivers to avoid getting into accidents with yellow taxis, leading to a lower accident rate.

    The study was led by Prof Ho. To test whether there was a causal relationship between the color of a taxi and the number of accidents the taxi had, the research team analysed data collected by the largest taxi company in Singapore. The researchers found that yellow taxis have about 6.1 fewer accidents per 1,000 taxis per month.

    The researchers also studied the economic effect of changing the color of the entire fleet of taxis to yellow. The Singapore taxi company involved in the study owns about 16,700 taxis in a ratio(比例) of one yellow to three blue taxis. If a commercial decision is made to switch from blue to yellow taxis, 76.6 fewer accidents would occur per month or 917 fewer accidents per year. Assuming an average repair cost of $1,000 per car and a downtime of six days, switching the color of all taxis to yellow could produce an annual savings of $2 million.

    "We are eager to continue to validate(证实) the findings of our study by looking at the use of yellow in other types of public transport, such as school buses. For instance, we hope to compare the accident rates of yellow school buses against other colors to find out if yellow is indeed a safer color for school buses. Besides, we are also interested to look at private-hire vehicles and do a comparison of the accident rates of vehicles that are of different colors," explained Prof Ho.

    With all the wars, fighting and sadness in the world today, it's not only necessary, but also essential to have a good sense of humor just to help us get through each and every day of our lives. Putting a smile on someone's face when you know they are feeling down in the dump, makes me feel good and warms my heart.

    How would you feel if you could not joke around with your wife, husband, child, co-worker, neighbor, close friends, or even just someone that you are standing in line with at your corner store? I am always saying things that make others smile or laugh, even if I don't know the person I'm joking around with. My Grandma always found humor in everything she did, even if it was the hardest job anyone could imagine. This not only relieves stress in any situation, but also is common courtesy(礼貌)to speak to others that are around you.

    I know of a few people that don't have a funny bone in their bodies, as they say. Everyone around them could be rolling on the floor after hearing a great joke and they would sit there without the s lightest smile on their face. They don't get the joke that makes others laugh. I am busting a gut while they just sit there, looking at me as if I were from outer space. How can people not get a really funny joke?

    Laughing is essential to keep your stress levels under control. Without humor we would find ourselves with a lot of psychological problems, or on a lot of medications to keep us from going crazy. There is too much sadness in this present world. It drives people crazy. We all need to find a way to ignore the sadness and bring a little light into our lives. So, I believe our best medicine is to get together and tell some jokes and have some fun laughing together.

    After the operation, Peter suffered severe pain, but insisted that he didn't need any treatment. One evening, he found Susan, his wife, crying in the kitchen of their apartment in a rare outburst of frustration. “If you won't help yourself, no one else can,” she said.

    Peter started a list “How to Help Myself”, and on it he wrote, “Keep communicating with the doctors, even if they are dark thoughts.” On October 20th, a few days before his 33 birthday, Peter wrote in a Facebook post, “It's been hard to get along with having an incurable Grade 4 brain cancer; it's been hard not to get angry and sad about it; and it's been hard to accept that modern medicine isn't able to fix me.” But at the same time, he wrote, “Every day I wake up not-dead is a gift.”

    Peter and Susan had other lists, detailing the things that they hoped to accomplish in life, which included a trip to Wimbledon; climbing Mt. Snowdon in Wales; and a list of musical wishes—from learning the Bach sonatas (奏鸣曲) and partitas (变奏曲) to performing the first violin part in a concert.

    Peter started working on Bach's six sonatas and partitas, the most difficult parts, which George Enescu, a world-famous violinist, once described as the Himalayas (喜马拉雅山) for violinists. Peter practiced every day, even if he could manage only fifteen minutes between medical treatments. As he mastered each piece, he posted his performances on Facebook. He finished on November 12th, then turned to the even more difficult Paganini caprices (随想曲), which he had often listened to in a recording by Itzhak Perlman. “It's something I always wanted to play when I grew up, like wanting to be a great baseball player,” he said.

    Janus, the Roman god, has two faces looking in opposite directions. So does artificial intelligence (AI). On one side are the positive changes, enabling people to achieve more, far more quickly, by using technology to improve their existing skills. Look the other way, though, and there are plenty of potential pitfalls.

    Like Janus, technological change may also cause disruption(混乱), but AI is likely to have a bigger impact than anything since the appearance of computers, and its consequences could be far more disruptive.

    In the years ahead, AI will raise three big questions for bosses and governments. One is the effect on jobs. Although CEOs publicly praise the broad benefits AI will bring, their main interest lies in cutting costs. One European bank asked Infosys to find a way of reducing the staff in its operations department from 50,000 to 500. The McKinsey Global Institute estimates that by 2030 up to 375m people, or 14% of the global workforce, could have their jobs replaced by AI.

    A second important question is how to protect privacy as AI spreads. The internet has already made it possible to track people's digital behavior in minute detail. AI will offer even better tools for businesses to monitor consumers and employees, both online and in the physical world. Consumers are sometimes happy to go along with this if it results in personalised service or promotions. But AI is bound to bring invasion of privacy that is seen as unacceptable. For example, law-enforcement officials around the world will use AI to spot criminals, but may also monitor ordinary citizens.

    The third question is about the effect of AI on competition in business. A technology company that achieves a major breakthrough in artificial intelligence could race ahead of rivals, put others out of business and lessen competition. This is unlikely to happen in the near future, but if it did it would be of great concern.

    It is too early to tell whether the positive changes brought by AI will outweigh the risk. But it will put an end to traditional ways of doing things and start a new era for business and for the world at large.

The Mona Lisa is the famous Leonardo da Vinci painting of a woman with a mysterious smile. This week, the painting gave up a secret.

Scientists used X-rays to examine the chemical organization of an extremely small part of the more than 500-year-old painting. The researchers discovered a technique Leonardo used in the work. A team in France and Britain discovered an oil paint used for the Mona Lisa was a special, new chemical mixture. It suggests that the Italian artist may have been in an experimental mood when he set to work on the painting early in the 16th century.

"He was someone who loved to experiment, and each of his paintings is completely different technically," said Victor Gonzalez. He is the study's lead writer. "In this case, it's interesting to see that indeed there is a specific technique for the ground layer of the Mona Lisa," he said in an interview with The Associated Press. Specifically, the researchers found a rare compound, plumbonacrite (水蛭石), in Leonardo's first layer of paint. The discovery, Gonzalez said, proved that da Vinci most likely used lead oxide to thicken and help dry his paint.

The scientists looked into its atomic structure using X-rays in a synchrotron (同步加速器). The machine moves particles at close to the speed of light, permitting researchers to look deeper into the paint structure. "Plumbonacrite is really a fingerprint of his recipe," Gonzalez said. "It's the first time we can actually chemically prove it."

Dutch artist Rembrandt may have used a similar mixture when he was painting in the 17th century. Gonzalez and other researchers have found plumbonacrite in his work, too. "It also tells us that those recipes were passed on for centuries," Gonzalez said. "It was a very good recipe."

But the Mona Lisa and additional works by Leonardo still have other secrets to tell. "There are plenty, plenty more things to discover," Gonzalez said. "What we are saying is just a little brick more in the knowledge."