Julian Beever is a well-known British artist. His drawings have appeared on the streets of London, Paris, Tokyo, New York and many other cities around the world. Beever creates what looks like a three-dimensional design (三维设计). From animals to heroes to buildings, the paintings are wonders for our eyes to see.

    In his book Pavement Chalk Artist, Beever shares some of his most attractive and humorous pieces. Here are the examples you will find in the book.

    Philadelphia Eagle, created in the USA, is a huge drawing with an eagle (鹰) landing on an American national flag. Meeting Mr. Frog was created in Spain and is about a realistic- looking (样子逼真的) frog sitting on a lily pad (睡莲叶子). Swimming Pool in the High Street is about a woman relaxing in a swimming pool sinking into the middle of the street.

    Along with an introduction about his background, Beever shares information about his time at home in the UK and abroad. With a fun story coming after each piece of art, this 112- page book is really worth another look.

    In recent decades, social isolation has been recognized as a major risk to our health and long life. It's twice as bad for you as being overweight and nearly as bad as smoking. The rising number of people who say they are affected, across a wide range of ages, is shocking. In reality, you can suffer the ill effects of loneliness even if you are not socially isolated.

Comedian Robin Williams made a striking observation in 2014: "I used to think the worst thing in life was to end up all alone. It's not. The worst thing in life is to end up with people who make you feel all alone." Tracking large groups over time indicates that perceived（感知的）social isolation carries its own risk for morbidity（发病率）and mortality.

    The perception of isolation—from others of being in the social aspect-is not only a cause of unhappiness, it also signals danger. Fish have evolved to swim to the middle of their group when predators（捕食者）approach, mice housed in social isolation show sleep disruptions and reduced slow-wave sleep and prairie voles（田鼠）isolated from their partners then placed in an open field explore their surroundings less and concentrate on avoiding predators.

    These behaviours reflect an increased emphasis on self-preservation in the social aspect. For instance, fish on the edge of a school are more likely to be attacked by predators because they are easier to isolate and prey upon. Such observations reflect a more general principle that perceived social isolation in social animals activates neural（神经系统的）, neuroendocrine（神经内分泌的）and behavioural responses that promote short-term self-preservation. However, these responses bring a cost for long-term health and well-being.

    The range of harmful neural and behavioural effects of perceived isolation documented in adults include increased anxiety, hostility and social withdrawal; fragmented sleep and daytime tiredness; increased vascular resistance and changed gene expression and immunity; decreased impulse control; increased negativity and depressive symptoms; and increased age-related cognitive decline.

    Sadly, to date, attempts to reduce loneliness have met with limited success. A series of randomized controlled trials showed that they had only a small effect. Among the four types of interventions（介入）examined, talking therapy that focused on inappropriate thought processes had the largest impact. Social skills training, social support and increased opportunities for social contact were much less effective.

    In its early history, Chicago had floods frequently, especially in the spring, making the streets so muddy that people, horses, and carts got stuck. An old joke that was popular at the time went something like this：A man is stuck up to his waist in a muddy Chicago street. Asked if he needs help, he replies, "No, thanks. I've got a good horse under me."

    The city planner decided to build an underground drainage （排水） system, but there simply wasn't enough difference between the height of the ground level and the water level. The only two options were to lower the Chicago River or raise the city.

    An engineer named Ellis Chesbrough convinced the city that it had no choice but to build the pipes above ground and then cover them with dirt. This raised the level of the city's streets by as much as 12 feet.

    This of course created a new problem: dirt practically buried the first floors of every building in Chicago. Building owners were faced with a choice: either change the first floors of their buildings into basements, and the second stories into main floors, or hoist the entire buildings to meet the new street level. Small wood-frame buildings could be lifted fairly easily. But what about large, heavy structures like Tremont Hotel, which was a six-story brick building?

    That's where George Pullman came in. He had developed some house-moving skills successfully. To lift a big structure like the Tremont Hotel, Pullman would place thousands of jackscrews （螺旋千斤顶） beneath the building's foundation. One man was assigned to operate each section of roughly 10jackscrews.At Pullman's signal each man tured his jackscrew the same amount at the same time, thereby raising the building slowly and evenly. Astonishingly, the Tremont Hotel stay open during the entire operation, and many of its guests didn't even notice anything was happening.

    Some people like to say that every problem has a solution. But in Chicago's early history, every engineering solution seemed to create a new problem. Now that Chicago's waste water was draining efficiently into the Chicago River, the city's next step was to clean the polluted river.

    I was so fortunate today to be able to offer my love and help to an older lady at my local supermarket. I saw her standing there. I felt quite strange about such a situation.

    What was she looking at? As I looked, I found it was a "Shredded Pork Bun Meal Kit", which is a service that sends customers food ingredients and recipes for them to prepare their own fresh meals. "That's new," I thought. Then I watched as the lady began to dig into her handbag and tried to pull out one of the biggest magnifying glasses (放大镜) I had never seen in my whole life! "Oh, she can't read it," I realized.

    So I stood there and continued watching her. The voice in my mind often asks me to do the right thing. It told me to help her. But I argued back saying, "No. I won't offer help. It will only embarrass her and she is OK now anyway. She has the world's biggest magnifying glass to help her！"

    And I stood there longer. But the voice came back, "Help her, Nicole. Don't be embarrassed. Just do it. Offer your help." So I did it. I read and explained all the things that were included in that box. I read out the ingredients, the instructions on how to cook it and so on.

    She didn't end up buying it, but she was still quite grateful. I walked away knowing that I had helped her and made the right choice. Mostly, I had reminded her that people in this world still care about the old.

    She was seen. She was loved. And she mattered so much that a complete stranger took time to help her. And that stranger was me, a person who argued and didn't want to do so in the beginning.

    So grateful I am when I choose to listen to the voice in my heart. It is because of love. Love is all that ever really matters. I also get happiness through helping her.

    Tiredness, coughing, a runny nose and a sore throat—among all sicknesses there is probably none more common than the flu (流感), which we all get now and then. However, bird flu is a completely different story.

    In 2003, the H5N1 bird flu swept across 15 countries, including China, with sufferers reporting chest pain, difficulty breathing, fever and severe coughing. More than 600 people were infected, and about 60 percent died. Now, another type of bird flu hit Shanghai and three neighboring provinces, and this time the virus is called H7N9. By the afternoon of April 11, the new virus had taken nine lives out of 35 infected, according to Xinhua News Agency.

    The "H" and "N" in the virus' name refer to two kinds of proteins (蛋白质) on the surface of the virus. Any change of the numbers of the two proteins indicates a new mutation(变异). Most of the mutations only affect birds, such as chickens and pigeons, and don't normally spread to humans. But once they do, the results can be disastrous.

    "Any time an animal influenza virus crosses to humans, it is a cause for concern, " Malik Peiris, virologist (病毒学家) at the University of Hong Kong, told Nature magazine. Take the SARS epidemic (传染病) in 2003 as an example. The virus behind the disease is thought to have jumped to humans from animals. The virus was a complete "stranger" to human bodies, which hadn't developed an immunity (免疫力) against it.

    But there is something more about the new H7N9 bird flu. Unlike the H5N1 bird flu, which causes severe sickness in birds, the H7N9 has been evolving under the radar(悄悄地) since it travels between birds without causing noticeable illness. That makes it difficult to keep track of the disease.

    The good news is that there's so far no sign that the virus is spreading from person to person. But since there is no vaccine (疫苗) for the disease yet, the World Health Organization recommends that you wash your hands after meeting with sick people and before and after you eat or prepare food, and they also suggest avoiding contact with birds or their eggs.

I first came across the concept of pay­what­you­can cafés last summer in Boone, N. C. , where I ate at F. A. R. M (Feed All Regardless of Means) Café. You can volunteer to earn your meal, pay the suggested price ($10) or less, or you can overpay—paying it forward for a future customer's meal. My only regret after eating there was not having a chance to give my time. So as soon as Healthy World Café opened in York in April, I signed up for a volunteer shift(轮班).

F. A. R. M and Healthy World are part of a growing trend of community cafés. In 2003, Denise Cerreta opened the first in Salt Lake City. Cerreta now runs the One World Everybody Eats Foundation, helping others copy her pay­what­you­can model.

"I think the community café is truly a hand up, not a handout," Cerreta said. She acknowledged that soup kitchens(施粥所) have a place in society, but people typically don't feel good about going there.

"One of the values of the community café is that we have another approach," she said. "Everyone eats here, no one needs to know whether you volunteered, overpaid or underpaid. "

The successful cafés not only address hunger and food insecurity but also become necessary parts of their neighborhood—whether it's a place to learn skills or hear live music. Some teach cooking to seniors; some offer free used books. Eating or working there is a reminder that we are all in this world together.

My 10 am～1pm shift at World Healthy Café began with the café manager—one of the two paid staff members. Our volunteer crew wasn't the most orderly, but we managed to prepare and serve meals with a lot of laughs in between. At the end of my shift, I ordered my earned meal at the counter, together with other volunteers. After lunch, I walked out the door, with a handful of new friends, music in my head and a satisfied belly and heart.