The meaning of silence varies among cultural groups. Silences may be thoughtful, or they may be empty when a person has nothing to say. A silence in a conversation may also show stubbornness, uneasiness, or worry. Silence may be viewed by some cultural groups as extremely uncomfortable; therefore attempts may be made to fill every gap (间隙) with conversation. Persons in other cultural groups value silence and view it as necessary for understanding a person's needs.

    Many Native Americans value silence and feel it is a basic part of communicating among people, just as some traditional Chinese and Thai persons do. Therefore, when a person from one of these cultures is speaking and suddenly stops, what maybe implied (暗示) is that the person wants the listener to consider what has been said before continuing. In these cultures, silence is a call for reflection.

    Other cultures may use silence in other ways, particularly when dealing with conflicts (冲突) among people or in relationships of people with different amounts of power. For example, Russian, French, and Spanish persons may use silence to show agreement between parties about the topic under discussion. However, Mexicans may use silence when instructions arc given by a person in authority rather than be rude to that person by arguing with him or her. In still another use, persons in Asian cultures may view silence as a sign of respect, particularly to an elder or a person in authority.

    Nurses and other care-givers need to be aware of the possible meanings of silence when they come across the personal anxiety their patients may be experiencing. Nurses should recognize their own personal and cultural construction of silence so that a patient's silence is not interrupted too early or allowed to go on unnecessarily. A nurse who understands the healing (治愈) value of silence can use this understanding to help in the care of patients from their own and from other cultures.

    Robert is a boss who hires me as a helper.He has lost his house and now has to live back at home,with his mother,at 46.

    We had a job in Fort Bending.Robert bought me breakfast there.As we were leaving,a man walked to us asking if he could get some work from Roberts' company.Robert explained there was no work for the man and the man started to walk away.As I looked at the man leaving from Robert,I saw Robert taking out some money and went after the man to gave it to him.I asked Robert,"Why did you do that?"Robert said "He really had bad luck—what does a few dollars matter?"

    After a very long,hard day,we stopped at a Quick Trip for a soda.I got through the checkout ahead of Robert and went back out to the work truck.Beside the truck was a woman in a car.She had 3 kids and asked me if I could help—she had been evicted and had nowhere to go with her children.They were living in the car.I told her I was also hurting in these times,so I could not.Robert came out,opened the work truck and we got in.I told him about the lady.I didn't even finish the story when Robert was out his door around the truck and gave the women money to help them out.When Robert returned I asked,"Why did you do that,she didn't even ask you".He said,“I have an ex-wife（前妻）and a kid.If they need help and I am not able,someone will help them”.

    I've written this article and you're reading it. So we are members of the same club. We're both literate—we can read and write. And we both probably feel that literacy is essential to our lives. But millions of people all over the world are illiterate. Even in industrialized Western countries, such as the UK and the USA, approximately 20% of the population have "low literacy levels". But what exactly does that mean?

    My parents both left school at 14. They could read and write, but except for a quick look at the daily newspaper, reading and writing didn't play a big part in their lives. There were very few books in the house. My mother was amazed because the woman who lived next door always wrote a list of what she needed before she went to the supermarket. Why couldn't she remember? We laughed about that for weeks. Our family didn't write lists! And when I was only 14 years old my father gave me an important letter that he'd written to the bank and asked me to check it for grammar and spelling mistakes. And there were quite a lot. He never usually wrote letters or postcards or even Christmas cards. So when he had to write he wasn't comfortable or confident. Does that mean that my father had a "low level of literacy"? I don't think so.

    There are lots of different definitions of literacy. Some experts define it as having the reading and writing skills that you need to be independent in your everyday life. So, for example, if you can read instructions, write a cheque, fill in a form, —anything that you need to do in everyday life—then you are "functionally literate".

    Other people say that you are illiterate if you think that you are illiterate. In other words, if you feel that you can't read or write as well as you would like to.

    If you live in a society where most people are literate then you will feel ashamed or embarrassed and avoid situations in which you have to read or write. The father of a friend of mine finally admitted to his family that he couldn't read when he was 45 years old. He bought the newspaper every day and pretended to read it—and believe it or not, his family had no idea.

    We often forget that writing is a recent invention. Many years ago, the word "literate" meant being able to communicate well in speaking, in other words what we now call "articulate". Story telling was an important activity in the past and still is today in some societies. Reading was often a cooperative activity—someone would read aloud to a group, often from a religious text such as the Koran or the Bible.

    Only a hundred years ago, in the United States, you were considered to be literate if you could sign your name to a piece of paper. It was an important skill. You were not allowed to vote if you couldn't sign the voting register, so literacy was connected with political rights, and many people were excluded from the democratic process.

    Nowadays we see reading and writing as being connected, but that wasn't so in the past. Many people could read, but not write. Writing was a skilled profession. If you needed something written then you paid an expert to write it for you.

    And of course, rich and important people have always employed people to write things for them. Important company bosses dictated letters to their secretaries or personal assistants. And now with new computer software you can dictate directly to your computer.

    Being illiterate can have a big effect on people's lives. For example, a study in the UK showed that people who write and spell badly are seen as careless, immature and unreliable, and often unintelligent. So it is more difficult for them to find jobs, even when reading and writing are not necessary for the work.

    World-wide statistics show that literacy problems are associated with poverty and a lack of political power. More women than men are illiterate. Illiterate people have worse health, bigger families and are more likely to go to prison. So literacy campaigns must be a good thing. But don't forget that an illiterate person, or someone with a low level of literacy, isn't necessarily stupid or ignorant—and may not be unhappy at all. Knowledge and wisdom isn't only found in writing.

    A new study by Chinese researchers has found differences in the brain activity of men and women addicted(上瘾的)to Internet gaming.

    The study says addicted men have lower impulse control compared with women, indicating that men are more likely to become addicted to internet gaming.

    Researchers from Renji Hospital, which is connected with Shanghai Jiaotong University, recruited 105 Chinese participants for the study, which had two groups - one with 32 men and 23 women addicted to gaming, and the other with 30 men and 22 women who were not addicted.

    They completed a questionnaire for gaming addiction, and reported their gaming history and number of hours playing per week. Researchers also talked with their families to collect the information.

    Through FMRI (磁共振扫描), researchers found that men addicted to gaming had lower brain activity in the brain region associated with impulse control, than nonaddicted men. The lower the activity levels, the poorer the impulse control. Addicted women, however, showed no differences compared with the healthy female group.

    Researchers also studied the functional connectivity between brain regions, which were lower in men with addiction than in nonaddicted men, but showed no differences in the female groups.

    Although there are some limitations, the findings suggest that activity levels displayed in the brain region could be biomarkers to evaluate the behavioral inhibitions of gaming-addicted men, they said.

    Gaming disorder was listed as a mental disorder by the World Health Organization earlier this year. People with the disorder have impaired control over gaming and give it increased priority in their lives－to the extent that gaming takes precedence over other life interests and daily activities.

    A good disguise keeps you hidden, right? Well, sometimes the best disguise is actually the most dazzling because research reveals that flashy metallic iridescence(金属彩虹色) can visually puzzle predators, which allows colorful prey to survive another day. Those surprising results appear in the journal Scientific Reports.

    Shining iridescent color, which changes depending on the angle from which it's viewed, is favored by everything from birds to beetles and blossoms to butterflies.

    "And in our research group we are of course interested in why this vivid metallic color is so widespread in nature." Karin Kjernsmo of the University of Bristol adds that in some cases the showy splashes of light are a sexual strategy. " Here I would like to point out that in some species, particularly those that display strong sexual dimorphism(雌雄两性), such as birds of paradise or some butterflies or fishes, the occurrence of iridescence is most likely driven by sexual selection. For example, in many of these cases it is the males that have these vivid iridescent colors and they use them in mate choice or they use them as a signal to attract mates."  But iridescence also shows up in situations where reproduction is not an issue. " So what we are studying now is whether natural selection imposed by predation(捕食行为) could explain the occurrence of iridescence in prey animals."

    The idea that eye­catching colors could be used as a cover­up isn't a new one." The father of camouflage theory, Abbott Thayer, really believed that iridescence should be categorized as a camouflage strategy. And he wrote in his famous lifework Concealing­Coloration in the Animal Kingdom, already in 1909, that 'brilliantly changeable or metallic colors are among the strongest factors in an animal's concealment'. And this sounds like a completely unreasonable thing to say, because how can colors that are both brilliant and changeable contribute to animal's concealment？"

    "In a similar way, we were asking whether iridescence, due to its changeability, could work as a form of camouflage by preventing shape recognition." Kjernsmo and her colleagues trained bumblebees to associate a particular shape—a circle or an oval—with a sugar reward. And they found that the bees, when given a choice, would preferentially visit the shape they knew to be sweet. But when the shapes were iridescent, the bees had trouble telling them apart. "It seemed that the strikingly iridescent surfaces on our targets visually broke up the otherwise recognizable shape of the targets, which made them hard to distinguish." As for making use of this method for hiding in plain sight, "Any practical applications is of course directly linked to any industry that has an interest in camouflage, that is how to conceal objects or make them more difficult to recognize." The researchers are currently conducting experiments with birds, which often prey on iridescent insects to see if it helps to have a bird's­eye view.

    It is well known that male humpback whales(座头鲸)are skilled singers. Their songs are thought to attract females in high frequency sounds while to compete with other males in low frequency sounds. Research led by the Wildlife Conservation Society has now made a new discovery.

    The study looked at the songs of two humpback whale populations, based on sound recordings collected from 2013 to 2018. One group was based in the South Atlantic, off the coast of Gabon, and the other in the Indian Ocean near Madagascar.  Analysis of the recordings showed that the two groups picked up musical ideas from each other and borrowed phrases and themes into their latest song. This suggested that the males from the two groups came into contact with each other over the five years and shared songs.

    To uncover this musical cooperation, researchers recorded the songs and transcribe them into more than 1,500 individual sounds and patterns, or song units.  They found that the units were composed into larger phrases, which were then repeated to form themes. These themes were sung for hours at a time, or even days. By 2018, both populations have been singing largely the same songs.

    "This similarity in the songs shows that these two populations come into closer contact than other southern populations, explains Dr Melinda Rekdahl, leading author of the study. As well as being an interesting phenomenon, she explains that those songs allow even greater insight into the workings of the humpback whale populations.