A warm drink of milk before bed has long been the best choice for those wanting a good night's sleep. But now a study has found it really does help people nod off—if it is milked from a cow at night.

    Researchers have discovered that “night milk” contains more melatonin(褪黑激素), which has been proven to help people feel sleepy and reduce anxiety.

    The study, by researchers from Seoul, South Korea, involved mice being fed with dried milk powder made from cows milked both during the day and at night.

    Those given night milk, which contained 10 times the amount of melatonin, were less active and less anxious than those fed with the milk collected during daytime, according to the study published in The Journal of Medicinal Food.

    Night milk quickened the start of sleep and caused the mice to sleep longer.

    While the effect of cows milk harvested at different times has not been tested on humans up to now, taking melatonin drugs has been suggested to those who are struggling to fall asleep at night.

    Previous studies have also indicated that milk can be excellent for helping sleep because of the calcium content, which helps people to relax.

    Milk is also sugar-free and additive-free with nutritionists recommending skimmed milk as the best choice before bed as it is the least fattening. The more fat you take in before bedtime, the greater burden you will put on your body at night.

    Danger-junkie orangutans(猩猩) in Borneo climb dead trees and shake then until they begin to fall. They scream with excitement as they cling to the falling tree. Just before the tree hits the ground the orangutans leap to another tree or vine, narrowly escaping death. While no one cab ask orangutans if they enjoy it as a person playing an extreme sport, one animal behaviorist sees this monkey fun as a bit of harmless thrill-seeking.

    A growing number of scientists agree that animals are conscious and capable of experiencing basic emotions(情感), such as happiness, sadness, boredom or depression. A few scientists even see the possibility for higher animal emotions like love, jealousy and spite.

    Five years ago, behaviorist and animal-rights activist Dr. Jonathan Balcombe stood on a Virginia hotel balcony watching two crows intimately groom (清洁) each other in the comfort of an abandoned billboard. He felt that the birds liked what they were doing, even if engaged in a natural, beneficial act, such as picking parasites (寄生虫) off the other's feathers. That moment changed the way he would view animals forever and led to a book, “Pleasurable Kingdom: Animals and the Nature of Feeling Good”, which is filled with hundreds of examples of animals living it up thanks to developed senses of touch, taste, sight, sound and smell.

    Balcombe recounts a favorite example of Kenyan hippos (河马) having high-end spa treatment in a fresh water spring. They splay their toes, open their mouths wide and wait for a school of cleaner fish to remove parasites and slough off dead skin, he recalls. Balcombe knows that the hippos and the fish both benefit from this arrangement. “My interpretation is that it is also enjoyable for them ,” he says.

    Travel is fun and exciting, but it's not if you get sick. You may think, “Not me, I won't get sick on my vacation. ”But for many people, that is what happens.

    A vacation is supposed to be a time for relaxing. But very often it is not.  “What can I do when I am a tourist?” This is what we should often think about.  Usually there are so many places to visit： museums, shops, parks and churches. You may spend most days walking around these places. This can be very tiring. Your feet may hurt.  And you may have a terrible headache after a few hours. If this is what you feel, you should take a rest. Don't ask your body to do too much. A tired body means a weak body. And a weak body can make you get sick easily. Just sit down for a few hours in a nice spot. In good weather, look for a quiet park bench. Or you can rest at a café. You can learn a lot by watching people when you have a rest.

    Sleep is also important. If you want to stay healthy you need enough sleep.  You may have trouble sleeping at night when you travel. Your hotel room may be noisy, or the bed may be uncomfortable.  If that is true, don't be afraid to change rooms or hotels. You may not get enough sleep for another reason. You may want to stay out late at night. In many cities the night life can be very exciting. Then you should plan to sleep for an hour during the day. That extra hour can make a big difference.

    Finally, if you want to stay healthy, you must eat well. That means eating the right kinds of foods. Your body needs fresh fruit and vegetables, and some meat, milk or cheese. When you are in a new country you may want to try new foods but you need to be careful about how much you eat. Lots of rich food is not very good for you.

    My first introduction to Chinese art was an early morning walk in Beihai Park in Beijing. There, I saw elderly people writing on the pavement with paintbrushes which were a metre long! I soon learned that they were doing water calligraphy − writing in water. The words have meanings, but they are also art. The calligraphy quickly disappears, of course. But tomorrow, the old people will be back.

    Temporary art like this is very popular in China. Every winter, Harbin, in northern China, is visited by sculptors and tourists from around the world. They come for the Harbin Ice Festival, when the city has huge sculptures made out of ice. The sculptures are bigger than houses, and they take weeks to make. Harbin's freezing winter temperatures make it very difficult for the artists to work outside. But the weather also means that the sculptures will be protected until the spring.

    Of course, not all Chinese art is temporary − some of it has been around for a very long time! Near the city of Xi'an, I visited the amazing terracotta warriors, or soldiers. In 200 BC, 8,000 statues of soldiers were made by sculptors out of a material called terracotta. They are as big as real people and they all have different faces. An important king had the statues produced to protect his body after he died. They stayed under the ground with the dead king for over 2,000 years, until they were discovered by a farmer in 1974.

    At the China Art Museum, in Shanghai, I saw wonderful 16th-century Chinese paintings of tall mountains, trees and cliffs. The paintings were beautiful, but they didn't look very realistic to me at the time. 'Mountains aren't like that,' I thought. But that was before the last stop on my trip: the mountains of Zhangjiajie National Park.

    These mountains were used by film director James Cameron in his sci-fi film Avatar because they look like something from another planet. On my last weekend in China, I took a cable car up into the mountains there. Trees grew on the sides of hundred-metre cliffs, and strange towers of rock appeared out of the morning fog. It looked just like the pictures in the China Art Museum. For a moment, I felt like I was inside a Chinese painting!

    I grew up in Bensonhurst, Brooklyn. When the holiday decorations went up, there were houses on my block with trees lit up for Christmas in front yards and behind living room windows. I was born in a Jewish family. Even though I received eight presents for Hanukkah (an eight-day Jewish holiday in November or December), it just wasn't fair. My friends had beautiful trees with lights and presents brought by a man in a red suit. I didn't have a tree, and I lived in an apartment building, so I had no chimney(烟囱).

    That year, some neighbors bought a Christmas tree, but it was too tall for their living rooms. They cut off the top and, knowing I wanted to celebrate Christmas, gave the top to my family. After my parents fell asleep, I opened a window in our apartment. I imagined Santa could park his sleigh(雪橇) on our fire escape. When I woke up the next morning, the window was closed and Santa had delivered a present. I can't even remember what it was, but my memory of the morning lasts.

    My relationship with Santa took a break until my daughter, Amanda, was born in 1992. My wife and I saw no reason to deprive(剥夺) her of meeting Santa. In 1998, a friend of mine portrayed(扮演) Santa at the South Street Seaport in Manhattan. He told me to stop by with my wife and daughter, and asked for their names in advance so he could greet them. When he saw us at the seaport, he greeted us by our names. My daughter's mouth opened wide and she pulled back. Maybe she was too young to appreciate this. But other families waiting to see him seemed delighted by his appearance and the gifts he brought.

    My two children are now grown up and do not visit Santa, and we do not have a Christmas tree, yet our family still enjoys the holiday. On Christmas Eve, in the spirit of the night, we leave a plate of my favorite cookies on the kitchen table in hopes Santa will leave a present.

    Depression(抑郁) can be a destructive illness, plaguing millions of people worldwide with feelings of sadness, hopelessness, and fatigue. Despite numerous antidepressant drugs, as many as a third of patients don't respond to medication. This has forced doctors to be more creative in finding different treatments for the condition.

    In the past two decades, researchers have tied depression to a seemingly unrelated condition: inflammation(炎症), the body's natural response to stress. It could rise from injury or inflection, or even emotional issues like an unhappy marriage or problems at work. Some amount of inflammation is generally beneficial, as it increases production of cytokines(致癌因子)，proteins that help us heal and protect us from the effects of overwork.

    But excessive cytokine levels, and the inflammation they bring on, could come at a cost—a number of studies suggests that high levels of cytokines could contribute to depression.

    Cytokines can reach the brain several ways: directly through the blood-brain barrier or indirectly by binding to nerve fibers elsewhere, which send signals to the brain to produce the inflammation molecules. In the brain, cytokines can disturb the production and release of several important signaling chemicals, including serotonin, dopamine and glutamate, which help control emotion, appetite, sleep, learning and memory. It's though that a lack of serotonin activity in the brain causes depression; most antidepressants increase the activity. But cytokines also have been shown to activate stress hormone signaling in the brain, which man also serve to develop depression.

    With all the evidence implicating inflammation in depression, doctors have been anxious to test anti-inflammatory drugs as a potential treatment. Four small studies published between 2006 and 2017 by research groups in Europe and Iran found that adults diagnosed with depression who took aspirin or another anti-inflammatory drug called Celecoxib, along with an antidepressant, got more relief from feelings of sadness, hopelessness, guilt and fatigue compared with those taking an antidepressant alone. However, Andrew Miller, a professor of psychiatry at Emory University, thought something was wrong in these small, limited studies. None of them looked at whether the participants had to have high levels of cytokines before they'd see a benefit from anti-inflammatory drugs.  "Unfortunately, much of the field has fallen into the trap of viewing inflammation as the be-all, end-all," Miller says. He and his colleagues wanted to see whether the effect of these drugs was limited to the depression patients with high cytokine levels, or if it helped all people diagnosed with depression.