According to a team of researchers, an animal's ability to perceive(感知) time is linked to their pace of life.

    “Our results lend support to the importance of time perception in animals where the ability to perceive time in a very short time may be the difference between life and death for fast moving creatures.” commented lead author Kevin Healy from Trinity College Dublin.

    The study was done with a variety of animals using phenomenon based on the maximum speed of flashes of light an individual can see before the light source is seen as constant. Dogs, for example, have eyes with a refresh rate higher than humans.

    One example of this phenomenon at work, the authors say, is the housefly and its ability to avoid being hit. The research showed flies “observe motion in a shorter time than our own eyes can achieve,” which allows them to avoid being hit.

    Professor Graeme Ruxton of the University of St Andrews in Scotland, who worked jointly on the research project, said in a statement, “Having eyes that send updates to the brain at much higher frequencies than our eyes do is of no Value if the brain cannot process that information equally quickly. Thus, this work highlights the impressive abilities of even the smallest animal brains. Flies might now be deep thinkers, but they can make good decisions very quickly.”

    In comparison, the tiger beetle (虎甲虫) runs faster than its eyes can keep up, basically becoming blind, which requires it to stop periodically to re-evaluate its prey's(猎物) position.

    Our results suggest that time perception offers an as yet unstudied dimension along which animals can specialize and there is considerable range to study this system in more detail.

    A new study shows students who write notes by hand during lectures perform better on exams than those who use laptops.

    Students are increasingly using laptops for note­taking because of speed and legibility(清晰度)．But the research has found laptop users are less able to remember and apply the concepts they have been taught.

    Researchers performed experiments that aimed to find out whether using a laptop increased the tendency to make notes“mindlessly”by taking down word for word what the professors said.

    In the first experiment，students were given either a laptop or pen and paper.They listened to the same lectures and were told to use their usual note­taking skills.Thirty minutes after the talk，they were examined on their ability to remember facts and on how well they understood concepts.

    The researchers found that laptop users took twice as many notes as those who wrote by hand.However，the typists performed worse at remembering and applying the concepts.Both groups scored similarly when it came to memorizing facts.

    The researchers' report said，“While more notes are beneficial，if the notes are taken mindlessly，as is more likely the case on a laptop，the benefit disappears. ”

    In another experiment aimed at testing long­term memory，students took notes as before but were tested a week after the lecture.This time，the students who wrote notes by hand performed significantly better on the exam.

    These two experiments suggest that handwritten notes are not only better for immediate learning and understanding，but that they also lead to superior revision in the future.

    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.

    Vinegar is great. It makes salad, fries and dumplings taste better, and you can even clean your windows with it. And now, according to scientists, it may even help the planet's population to ease hunger.

    Researchers from the RIKEN Center for Sustainable Resource Science (CSRS) in Japan found that growing plants in vinegar makes them more resistant to droughts.

    This could mean that in the future, worries about climate change affecting the world's supply of food will be much lower.

    The discovery was made after the researchers studied the Arabidopsis, a plant known for its ability to survive in dry weather. It was found that when the plant was placed in drought-like conditions, it produced a chemical called acetate(醋酸盐) – the main component of vinegar.

    After discovering this, the scientists experimented further by adding acetate to the soil of other plants, before they stopped giving them water completely. After leaving the plants for 14 days, they found that the ones treated with acetate had survived, while the untreated plants had dried up and died. It's hoped that this simple method of survival could soon be used to help farmers in dry countries keep their crops alive.

    Jong Myong Kim, co-author of the study, told Popular Science magazine that he's already been in touch with people all over the world who are interested in trying this simple and cost-effective method out for themselves from flower growing companies to amateur gardeners.

    Although at this point keeping thirsty plants alive isn't as easy as just pouring vinegar over them, Kim said he and his team are working on making the process as simple as possible. "Now we are trying to cooperate with some farmers, and also some companies, to make a method to apply this system." he said.

    And for those of us who always forget to ask our neighbors to water our plants when we go away, hopefully this means the end of returning home from a trip to find our favorite flowers have died.

    You can't see your sleeping pets brain waves, but its behavior can tell you when your cat might be dreaming. If you watch closely, you'll see that as she falls asleep, her breathing becomes slow and regular with her body still. She has entered the first stage of sleep, called slow-wave sleep. After about 15 minutes you'll notice a change in her breathing. Her eyes move under her closed lids, her paws twitch (抽动) and she flicks (尤指用手指或手快速地轻抚) an ear. She has entered dreaming. Although she twitches and makes little grunting (嘟嘟) noises, messages from her brain to the large muscles in her legs are blocked, so she can't run about. She is in a state of "sleep paralysis (麻痹)".

    Michel Jouvet, a French scientist, interrupted their sleep paralysis. Even though they were completely asleep, the dreaming cats began to run for balls that Jouvet couldn't see and arched (弓起) their backs at unseen enemies. He figures he was watching them act out their dreams! Obviously, the dreaming cats seemed to be practising important cat skills: following, pouncing (猛扑), and fighting.

    In another study, Matt Wilson recorded rats brain waves while they learned mazes (迷宫). One day, he left the brain-wave-recording machine on while the rats fell asleep. The pattern of brain waves in the sleeping rats matched the pattern from the maze so closely that Wilson could figure out exactly which part of the maze each rat was dreaming about!

    Many researchers now think that in both people and animals, one purpose of dreams is to practise important skills and figure out recent caning. This may explain why so many people dream about fighting and escaping, skills that were probably important to our ancestors, and why dreaming affects our ability to learn.

    Do all animals dream? From looking at the brain waves of sleeping animals. How often animals dream seems to be tied to body size. Cats dream about every 15 minutes, mice every 9 minutes, and elephants every 2 hours. And though cows and horses usually sleep standing up, they only dream when lying down.

    Laughter is a kind of universal body language that is shared by people of all nationalities, skin colors, cultures and traditions. But did you know that the ability to tell real laughter apart from fake (假的) laughter also varies among cultures?

    Greg Bryant, a professor of communication at the University of California, published a study in late July. In the study, 884 people from 21 countries were asked to listen to random recordings of laughter. Some of the recordings were made up of laughs from the bottom of the heart, while others were made by people who were asked to laugh on command.

    The study showed that people around the world have the ability to pick out real laughter, although their abilities vary from country to country. Residents of the Samoan Islands, were particularly good at it, correctly identifying real laughter 56 percent of the time. According to Bryant, people from smaller, less industrialized nations “are more accurate in identifying a natural smile” because they rely heavily on emotional engagement in order to predict others' behavior and create stronger social relationships.

    But how do people from different cultures detect natural laughter so easily? And what characters does real laughter have? As Professor Jessica Wolf of the University of California told the Association for Psychological Science, in real laughter, we produce qualities, such as higher pitch (音调) and volume, as well as faster bursts of no clear sounds.

    By contrast, fake laughter will "sound like speech". According to Science Daily, fake laughter is controlled by the same brain system that controls the lips and tongue. Bryant further explained that this system has active ability, saying "with this speech system, you can make a lot of different noises, including crying, laughter or scream. That's where fake laughter comes from".

    So that? s something to think about: next time one of your friends laughs at something you say, will you be able to tell if it's real or fake?