“Heaven (天堂) is where the police are English, the cooks are French, the mechanics are German, the lovers are Italian and everything is organized by the Swiss. Hell (地狱) is where the police are German, the cooks are English, the mechanics are French, the lovers are Swiss, and everything is organized by the Italians.”

    Obviously the national stereotypes (模式化的思想) in this old joke are generalizations (普遍化), but such stereotypes are often said to “exist for a reason”. Is there actually a sliver (裂片) of truth in them? Not likely, an international research team now says.

    “National and cultural stereotypes do play an important role in how people see themselves and others, and being aware that these are not dependable is a useful thing,” said study author Robert McCrae of the National Institute on Aging. “These are in fact unfounded stereotypes. They don't come from looking around you,” McCrae said.

    If national stereotypes aren't rooted in real experiences, then where do they come from? One possibility is that they reflect national values, which may become known from historical events. For example, many historians have argued that the spirit of American individualism (个人主义) has its origins in the experiences of the pioneers on the Old West.

    Social scientists such as psychologist Richard Robins have given several other possible explanations for stereotypes and why they may be incorrect. Robins notes that some stereotypes may have been correct at one point in history and then remained unchanged while the culture changed.

    We may be “hard-wired”, to some degree, to keep incorrect stereotypes, since we are less likely to notice and remember information that is different from our stereotypes. Generally, according to Robins, when we meet people who are different from our stereotypes, we see them as unique individuals rather than typical national or cultural groups.

    Time flies, but the tracks of time remain in books and museums. This is what made a recent tragedy in Brazil even more terrible.

    On Sept.2, a big fire ripped through the National Museum of Brazil. "Two hundred years of work, research and knowledge were lost," Brazilian President Michel Temer wrote on Twitter after the fire. "It's a sad day for all Brazilians."

    Most of the 20 million pieces of history are believed to have been destroyed. Only as little as 10 percent of the collection may have survived, Time reported. Among all the items, there were Egyptian mummies, the bones of uniquely Brazilian creatures such as the long－necked dinosaur Maxakalisaurus, and an 11,500－year－old skull called Luzia, which was considered one of South America's oldest human fossils.

    Besides these, Brazil's indigenous(本土的，土著的) knowledge also suffered. The museum housed world－famous collections of indigenous objects, as well as many audio recordings of local languages from all over Brazil. Some of these recordings, now lost, were of languages that are no longer spoken.

    "The tragedy this Sunday is a sort of national suicide, a crime against our past and future generations," Bernard Mello Franco, one of Brazil's best－known columnists, wrote on the O Globo newspaper site.

    The cause of the fire is still unknown, as BBC News reported on Sept. 3. After the fire burned out, crowds protested outside the museum to show their anger at the loss of the irreplaceable items of historical value.

    According to Emilio Bruna, an ecologist at the University of Florida, museums are living, breathing stores of who we are and where we've come from, and the world around us.

    Just as underwater grass floats on the surface if it loses its roots, a nation is lost without its memories. The fire at the National Museum of Brazil teaches the world an important lesson: We should never neglect history.

    Artificial intelligence (AI) technology may soon be a useful tool for doctors. It may help them better understand and treat diseases like breast cancer in ways that were never before possible.

    Rishi Rawat teaches AI at the University of Southern California's (USC) Clinical Science Center in Los Angeles. He is part of a team of scientists who are researching how AI and machine learning can more easily recognize cancerous growths in the breast. Rawat provides information about cancer cells to a computer. He says this data helps the machine learn. “…You can put the data into them and they will learn the patterns and the pattern recognition that's important to making decisions.”

    David Agus is another USC researcher. He believes that “machines are not going to take the place of doctors.” He adds, “Computers will not treat patients, but they will help make certain decisions and look for things that the human brain can't recognize these patterns by itself.”

    Once a confirmed cancerous growth is removed, doctors still have to treat the patient to reduce the risk of cancer returning. The form of treatment depends on the kind of cancer. Currently, researchers take a thin piece of tissue, put it on a small piece of glass and add color to better see the cells. This process could take days or even longer. Scientists say artificial intelligence can do something better than just count cells. Through machine learning, it can recognize complex patterns, or structures, and learn how the cells are organized. The hope is that machines will soon be able to make a quick diagnosis（诊断）of cancer that is free of human mistakes.

    “All of a sudden, we have the computing power to really do it in real time...We couldn't have done this, we didn't have the computing power to do this several years ago, but now it's all changed.” Agus adds that the process could be done “for almost no cost in the developing world.” He says that having a large amount of information about patients is important for a machine to effectively do its job in medicine.

    A doctor faces a series of critical decisions every day. The best a doctor can do is to make those decisions as informed as possible. Some of them are still hard to make. A doctor can ask people of whom he values their opinions and that's it. Imagine discussing these with an AI system that is even more rational（理性的）than anyone else.

    The University of Southern California researchers are now only studying breast cancer. But doctors predict artificial intelligence will one day make a difference in all forms of cancer.

    There were smiling children all the way. Clearly they knew at what time the train passed their homes and they made it their business to stand along the railway, wave to complete strangers and cheer them up as they rushed towards Penang. Often whole families stood outside their homes and waved and smiled as if those on the trains were their favorite relatives. This is the simple village people of Malaysia. I was moved.

    I had always traveled to Malaysia by plane or car, so this was the first time I was on a train. I did not particularly relish the long train journey and had brought along a dozen magazines to read and reread. I looked about the train. There was not one familiar face. I sighed and sat down to read my Economics.

    It was not long before the train was across the Causeway and in Malaysia. Johore Baru was just another city like Singapore, so I was tired of looking at the crowds of people as they hurried past. As we went beyond the city, I watched the straight rows of rubber trees and miles and miles of green. Then the first village came into sight. Immediately I came alive; I decided to wave back.

    From then on my journey became interesting. I threw my magazines into the waste basket and decided to join in Malaysian life. Then everything came alive. The mountains seemed to speak to me. Even the trees were smiling. I stared at everything as if I was looking at it for the first time.

    The day passed fast and I even forgot to have my lunch until I felt hungry. I looked at my watch and was surprised that it was 3:00 pm. Soon the train pulled up at Butterworth. I looked at the people all around me. They all looked beautiful. When my uncle arrived with a smile, I threw my arms around him to give him a warm hug (拥抱). I had never done this before. He seemed surprised and then his weather-beaten face warmed up with a huge smile. We walked arm in arm to his car.

    I looked forward to the return journey.

    Batteries can power anything from small sensors to large systems. While scientists are finding ways to make them smaller but even more powerful, problems can arise when these batteries are much larger and heavier than the devices themselves. University of Missouri (MU) researchers are developing a nuclear energy source that is smaller, lighter and more efficient.

    "To provide enough power, we need certain methods with high energy density (密度)", said Jae Kwon, assistant professor of electrical and computer engineering at MU. ''The radioisotope (放射性同位素) battery can provide power density that is much higher than chemical batteries."

    Kwon and his research team have been working on building a small nuclear battery, presently the size and thickness of a penny, intended to power various micro systems (MNEMS). Although nuclear batteries can cause concerns, Kwon said they are safe.

    "People hear the word 'nuclear' and think of something very dangerous." he said. "However, nuclear power sources have already been safely powering a variety of devices, such as pace-makers, space satellites and underwater systems."

    His new idea is not only in the battery's size, but also in its semiconductor (半导体). Kwon's battery uses a liquid semi conduct or rather than a solid semiconductor.

    "The key part of using a radioactive battery is that when you harvest the energy, part of the radiation energy can damage the lattice structure (晶体结构) of the solid semiconductor." Kwon said, "By using a liquid semiconductor, we believe we can minimize that problem."

    Together with J. David Robertson, chemistry professor and associate director of the MU Research Reactor, Kwon is working to build and test the battery. In the future, they hope to increase the battery's power, shrink its size and try with various other materials. Kwon said that battery could be thinner than the thickness of human hair.

    "When someone is rude to you, it can put you in a bad mood. It may even lead you to be rude to someone else, creating a chain of rudeness. In fact, this troubling chain may even be caused by simply seeing someone be rude to another person. You don't even have to be the target of the had behavior," stated a researcher.

    The researchers worked with 81 persons, with occupations ranging from security to business to medicine, who were asked to complete online surveys over a 10-day period. Participants recorded their moods when they woke up; and in the evening, they described their experiences over the course of that day.

    Each morning the participants also viewed a short video, describing workplace interaction of some kind. Half of the mornings, the video included some kind of rudeness while the other half had some kind of warm interaction in the workplace. Rudeness was conveyed through various means, including a lack of eye contact or unpleasant language.

    Participants who watched the rudeness videos reported seeing or experiencing rudeness during the day, and they were also more likely to escape from fellow employees to avoid being the victims of rudeness themselves. They reported their overall work suffered that day as a result.

    Not all participants were affected by the rudeness videos, however. A few weeks before the study began, the participants completed an evaluation that measured their self-confidence and emotional stability among other things. The participants who scored higher on this evaluation were significantly less likely to be influenced by the rudeness.

    Consequently, one of the researchers recommended that companies hire managers who can limit exposure to rudeness, provide plenty of positive reinforcement (强化) and build a civil workplace environment. This, in turn, could help employees build their confidence levels and help them better handle workplace rudeness.