A five-year-old dog named Kelsey has been praised as a hero for helping to save the life of her owner who slipped in the snow and broke his neck.

    The man, Bob, was alone when he left his Michigan farmhouse on New Year's Eve to collect firewood. Expecting a journey of only several meters, Bob was wearing just long johns (衬裤), a shirt and slippers when he went outside, although the temperature was around -4℃.

    After the accident, he was unable to move in the snow. Fortunately, Kelsey came to his assistance.

    "I was shouting for help, but my nearest neighbor is about 400 meters away, and it was 10:30 pm, Bob explained." But my Kelsey came. By the next morning, my voice was gone and I couldn't yell for help, but Kelsey didn't stop barking."

    Kelsey's companion kept him warm by lying on top of him. She licked his face and hands to keep him awake." Kelsey kept barking but never left my side," Bob recalled. "She kept me warm. I knew I couldn't give up and that it was my choice to stay alive."

    Bob spent 20 hours in the freezing cold. When he finally lost consciousness, his dog kept barking. Finally, hearing the barking, Bob's neighbor discovered him at 6:30 pm on New Year's Day and called the emergency services at once. When Bob arrived in hospital, his body temperature was below 21℃. However, doctors were surprised to find that he didn't have any frostbite (冻疮). They believed it was because of Kelsey's determination to keep him warm, Dr. Chaim Colen, the doctor who treated Bob, said, "Animals can help and his dog really saved him... He was very fortunate.”

    Bob said he was "enormously" grateful to both Dr. Colen and his Kelsey, "They saved my life. They are truly heroes!"

    Youth volunteers from Beijing University visited Song tang Hospital, a care clinic for the aged and dying patients, during the second Global Youth Service Day on April 21．

    Thirty student volunteers from the university's School of International Studies sat at the beds of the patients in their specially decorated “care huts”. They talked with them and gave massages （按摩）to patients kept in their beds.

    I felt sorry that I could not offer more to these people than talking with them and trying to cheer them up, said Deng Yetao, 20, a third - year student. “But it occurred to me that they need more care and love than babies. They are afraid of the coming death. Their loneliness is worse than physical pains.”

    “Even though they are suffering a lot, the majority of the elderly people want to talk to us. Each of them has a lot of life experiences and philosophies to share. Instead of doing them a favor, I felt I was gaining a valuable lesson. Said Mao Xiaohua, another third - year student.

    Mao talked with two elderly patients for a whole afternoon. The fact that most of the patients in the 80 - room clinic are aged people with diseases which will lead to death soon made the volunteers' hearts heavy.

    Ninety - one percent of the patients will spend the last days of their lives in the clinic, according to a survey by the hospital.

    Daily visits and services by social workers and youth volunteers are a very important part of their programmer. A total of 330, 000 Beijing students from 119 universities and colleges have visited the hospital. Many continue to offer services in their spare time. Some of them volunteer to hold the hands of dying patients during the last minutes of their lives.

    Yin Hang, a student from Beijing Medical College, said he felt“ the glory of life” as he saw the fading smile on the face of the old man who passed into a deep unconsciousness（昏迷）while he was holding his hands.

    Why can some people sleep through noises like a honking car or flushing toilet, while others are awakened by the lightest sound?

    To find the answer, sleep researchers at Massachusetts General Hospital conducted an unusual study of 12 self-described deep sleepers. After tests confirmed that the healthy volunteers were solid sleepers, they took part in a three-night study in the university's sleep laboratory. The participants spent the night in a big and comfortable room. But the room also included four speakers positioned near the top of the bed.

    During the night, the deep sleepers were subjected to 14 different recorded sounds, like street traffic, toilets flushing, and an airplane flying overhead. Next door, the researchers monitored their sleep patterns and brain waves.

    As expected, all of the participants slept relatively well, but there were differences in how they responded to the noisy interruptions. Some of the sleepers didn't wake up even when a sound was blasted at 70 decibels（分贝）; others were awakened by sounds at 40 or 50 decibels.

    The researchers discovered that the difference in a sleeper's reaction to noise could be predicted by the level of brain activity called "sleep spindles（纺锤体）". A sleep spindle is a burst of high-frequency brain activity coming from deep inside the brain during sleep. The source of the spindles is the thalamus（丘脑）, a part of the brain that sends sensory information to the rest of the cortex（皮层）.

    Before the study, the Massachusetts researchers theorized that the spindles are the brain's way of preventing sensory information from passing through the thalamus and waking the rest of the brain during sleep. They found that sleepers who experienced the most sleep spindles during the night were also the soundest sleepers and were least likely to be awakened by noise.

    Scientists already know that most people become lighter sleepers with age, most likely because older people experience less "slow wave sleep", which is the deepest stage of sleep. People also produce fewer sleep spindles as they age. But even when controlling for the stage of sleep a person was in, the number of sleep spindles still predicted their risk for awakening because of noise.

    More research is needed, but the findings suggest that a better understanding of sleep spindles could lead to new behavioral or drug therapies for people with sleep disorders. For example, future studies may try to determine whether diet, exercise or other behaviors may influence the number of sleep spindles a person produces during the night.

    We bet that on cold winter days, many of you love to stay in your warm home and, every now and then, come out into the kitchen for a snack. Unfortunately, plenty of small insects like to do the same thing! Winter is the time when small insects enter your house without an invitation. The season can be difficult for such creatures. In winter the air is cold, the ground is hard and many trees have no leaves. So small insects do what they have to do to survive.

    Monarch butterflies head south to warmer climates. Ants crowd in deep underground colonies and eat food they have been storing all year. Many insects go into a deep sleep called diapauses. There're different kinds of diapauses, but all are similar to hibernation, a time when bigger animals become inactive in the cold. Insects go into an inactive period, too, but it often isn't when the temperature drops.

    They rely on more dependable signals in the environment. For example, many insects can tell how much sunlight there's each day. They use that to tell themselves when to shut down. Insects are cold-blooded, meaning that their inside temperature is the same as the outside. They can't move much when it gets below 40 degrees Fahrenheit. So they search for any warm place.

    They're looking for protection. These guys have been doing this for 300 million years, so they don't really know they're coming into your house. The home is a recent event in terms of their evolutionary (进化的) behavior. They enter through tiny cracks or come in unnoticed on your clothes or shoes. Remember that they may be entering your homes for warmth and food, but they don't care about humans.

    Every week in China, millions of people will sit in front of their TVs watching teenagers compete for the title Character Hero, which is a Chinese­style spelling bee (拼写大赛). In this challenge, young competitors must write Chinese characters by hand. To prepare for the competition, the competitors usually spend months studying dictionaries.

    Perhaps the show's popularity should not be a surprise. Along with gunpowder and paper, many Chinese people consider the creation of Chinese calligraphy (书法) to be one of their primary contributions. Unfortunately, all over the country, Chinese people are forgetting how to write their own language without computerized help. Software on smart phones and computers allows users to type in the basic sound of the word using the Latin alphabet(字母). The correct character is chosen from a list. The result? It's possible to recognize characters without remembering how to write them.

    But there's still hope for the paint brush. China's Education Ministry wants children to spend more time learning how to write.

    In one Beijing primary school we visited, students practice calligraphy every day inside a specially decorated classroom with traditional Chinese paintings hanging on the walls. Soft music plays as a group of six­year­olds dip brush pens into black ink. They look up at the blackboard often to study their teacher's examples before carefully trying to reproduce those characters on thin rice paper. "If adults can survive without using handwriting, why bother to teach it now?" we ask the calligraphy teacher, Shen Bin. "The ability to write characters is part of Chinese tradition and culture," she reasons. "Students must learn now so they don't forget when they grow up." says the teacher.

    Auctions (拍卖行) are everywhere. Here are just a few standouts and some of the areas they specialize in. All have brick-and-mortar (实体的) sales rooms in addition to online buying.

    Leslie Hindman Auctioneers

    Headquarters (总部): Chicago

    Founded: 1982

    Best bets: contemporary art, jewelry

    The founder, Leslie Hindman, has been on an expansion kick from her Chicago base and now runs eight offices across the country. Ms. Hindman said that plenty of items sell at her house for around $500. As in the auction world generally, jewelry and contemporary art receive lots of attention from bidders (出价者), and in 2017 a diamond ring sold for $97,000.

    Swann Auction Galleries

    Headquarters: New York

    Founded: 1941

    Best bets: books, works on paper, African-American art

    Founded as a rare-book auctioneers, Swann still holds dozens of such sales a year. The president, Nicholas D. Lowry, noted that Swann was the first auction house to sell old photographs, in 1952. The house has also had a department of African-American art for 12 years.

    Stair Galleries

    Headquarters : Hudson, N. Y.

    Founded: 2001

    Best bets: English and Continental furniture and paintings, modern and contemporary art

    Colin Stair, the founder and president, comes from a long line of antiques dealers. Stair is frequented by dealers and bargain hunters, and it's a place to find interesting things like a Gorge I carved walnut wing armchair, coming up as part of a sale on April 28 and 29.

    Heritage Auctions

    Headquarters : Dallas

    Founded: 1983

    Best bets: coins, sports memorabilia, movie posters

    With roots in coin auctions Heritage has grown quite large. But their bread and butter are items that the company president, Greg Rohan, calls "the kinds of things that everyone has." "People aren't buying what we're selling for decoration or for resale," he added. "They're buying things they absolutely love."