We all have dreams sometimes. Some are sweet but some are nightmares. Almost all researchers in sleep explain that nightmares are a reaction to negative experiences that happen during waking hours. However, some of them believe that nightmares do have some real benefits. One 2017 study, for example, found that frequent nightmare sufferers rated themselves as more empathetic（共鸣的）.They also displayed more of a tendency to unconsciously mirror other people through things like yawning. People who have constant nightmares also tend to think further outside the box on psychoanalysis tasks. Some other researchers have found support for the idea that nightmares might be linked to creativity.

    People seeking cure for nightmares were not necessarily more fearful or anxious, but rather had a general sensitivity to all emotional experience. Sensitivity is the driving force behind intense dreams. Heightened sensitivity to threats or fear during the day results in bad dreams and nightmares, whereas heightened passion or excitement may result in more intense positive dreams. And both these forms of dreams may feed back into waking life, perhaps increasing suffering after nightmares, or promoting social bonds and empathy after positive dreams.

    The effects go further still. This sensitivity overflows over into perceptions and thoughts: people who have a lot of nightmares experience a dreamlike quality to their waking thoughts. And this kind of thinking seems to give them a creative edge. For instance, studies show that such people tend to have greater creative talent and artistic expression. And people who often have nightmares also tend to have more positive dreams than the average person.

    The evidence points towards the idea that, rather than disturbing normal activity, people who are unfortunate in having a lot of nightmares also have a dreaming life that is at least as creative, positive and vivid as it can be distressing and terrifying. What's more, this imaginative richness is unlikely to be limited to sleep, but also is filled with waking thought and daydreams. Even after people wake up and shake off the nightmare, in other words, a mark of it stays behind, possessing them throughout the day.

    Last night, on my way home I stopped because of being attracted by some hamburgers at a fast food restaurant. On my way in, a homeless man approached me and asked, “Do you have any bottles lying around?” I knew he would recycle them for a few cents, but I didn't have any, so I said no. And again he asked, “Can you spare some change (零钱)?” I smiled, and said no again. He was very respectful; he smiled back and said, “OK, thank you.” Even though he didn't have anything, he was still in good spirits. From the way he spoke I could tell he was smart.

    Then I bought one hamburger and enjoyed my meal, but in the back of my mind I wondered whether the homeless man was hungry. After I finished my meal I decided to order another one for him. At this point I didn't know if he was still around, but I tried anyway.

    At the counter I ordered a hamburger and also a hot chocolate, because it was cold outside, and I thought it would help warm him up. They delivered me the hot chocolate first and as I waited for my hamburger, I noticed the homeless man was standing right beside me. I looked at him and smiled, “This hot chocolate is for you.”He replied like a gentleman,“Thank you so much. That's very kind of you.”

    I always believe no matter how hard up (缺钱) I am, there are always those who are worse off than I. When you help someone, it's not always about money, it's about love. The love you give today, someone might forget tomorrow. It doesn't matter. Love anyway, because the greatest thing you can give is love.

    Researchers have created a backpack that has a computer and medicines in it that can help even untrained soldiers save the lives of wounded troops. Wounded soldiers have a better chance of survival if they get help soon after being hurt and are quickly taken to a hospital or clinic. But soldiers who do not have medical training may not know how to help their injured friends.

    Doctors and engineers have developed what they call an “intelligent backpack”. It has a computer and electronic measuring devices. The backpack also has robotic instruments and medicines ready to give to injured troops.

    About 16 doctors and engineers from the University of Pittsburgh, Carnegie Mellon University and several other places are working on the project. The U. S. Department of Defense has given money to the project.

    Ron Poropatich leads the project. He is a retired army surgeon. He says the backpack will help soldiers care for those who are injured. The devices included in the backpack can monitor a person's heart rate and blood pressure. The robotic instruments can even tell whether the soldier has a collapsed lung.

    The intelligent backpack's computer can compare information gathered about the injured soldier with thousands of similar cases, and quickly tell the best methods to use to save the soldier's life.

    Sometimes, it is not always possible to quickly remove the injured soldier from the battlefield. So, Dr. Poropatich says, the researchers hope to create a backpack that will have devices that can keep a soldier alive for a long time. Dr. Poropatich hopes the backpack and its instruments will be ready for testing animals in about three years.

    If your dog looks pleased to see you—it is probably because it loves the particular way you smell.

    The scent (气味)of a familiar human apparently lingers like perfumein the animal's brain—where it causes an instinctive emotional response, research reveals.

    Our scent acts on a part of the canine (犬科的) brain associated with reward and the strongest reactions are produced by humans that pets know best, say scientists in America.

    Gregory Bern, of Emory University in Atlanta, said, “While we might expect that dogs should be highly tuned to the smell of other dogs, it seems that the 'reward response' is reserved for their humans. When humans smell the perfume of someone they love, they may have an immediate, emotional reaction that's not necessarily cognitive (认识的). So is it in dogs. But since dogs have a more sensitive smell than humans, their responses would likely be even more powerful than the ones we might have. In our experiment, however, the owners of the dog were not physically present. The canine brain responses were being caused by something distant in space and time. It shows that dogs' brains have these mental representations of us that persist when we're not there.”

    The experiment involved 12 dogs of various kinds by brain scans while five different scents were placed in front of them. The scent samples (样本)came from the subject (接受试险者) itself, a dog the subject had never met, a dog living in the subject's household. The familiar human scent samples were taken from someone else from the house other than the handlers during the experiment, so that none of the scent donors were physically present.

    The results showed all five scents gained a similar response in parts of the dogs brains involved in detecting smells. Responses were significantly stronger for the scent of familiar humans, followed by that of familiar dogs. The findings showed dogs reacted strongest to the scent of familiar humans even when they were not there. Pets trained as help or therapy dogs showed greater brain activity than the other dogs in the test.

    Researchers say the findings could improve the way to select animals helping wounded old soldiers or disabled people.

    I was deeply moved by the kindness of an elderly flower seller at Sydney's Central Station one evening.

    I was feeling as cold as the winter winds quickening the steps of the people who buried chins (下巴) in scarves and hands deep into coat pockets. In many ways, 2018 had proven an arduous year. My teenage daughter had left home for university, my job of 23 years was no more, and a creative project I'd given my all to for years had also been suddenly called off. I also found out a person I considered a friend was far from it.

    A year earlier, I'd dreamt about an earthquake. In the dream, a red light flashed inside a building and then the earth began to rock. Walls fell down on me as I ran into the open, feeling sorry for the people I hadn't loved enough. Before I was buried completely by the falling world, I shouted, "Abuelo, ayudame," in my native Spanish. "Grandfather, help me!"

    Now, with the very real aftershocks of a series of unexpected endings, I walked into a little flower shop to buy a gift for a friend. The gentleman at the shop looked at me and turned away for a moment, returning with a fragrant flower. "For you. You need to smile today," he said in a rich and beautiful accent, offering me the flower with eyes full of care. It took all my strength not to cry. Then he gave me a grandfatherly hug that made me want to tell him everything.

    Instead, I thanked him and headed for the train. How did he know? I wondered. For the first time in weeks, I felt hope.