Dolphins(海豚) live in a dark underwater world. It's often impossible to see each other or anything else around them, so sound plays an important role in their survival. To communicate with each other, dolphins produce all kinds of sounds.

    Only other dolphins understand what the sounds mean. Scientists haven't uncovered their secret communication, except for one kind of whistle. It might last less than a second, but this whistle is a big deal. Why? Because these whistles are actually names of dolphins - and every dolphin has one. Scientists call these sounds a “signature whistle.” When other dolphins hear the whistle, they know which dolphin is calling.

    Dolphins often hunt by themselves but still need to stay connected to the group. Since they can't always see each other, dolphins use their signature whistles to check in with other dolphins hundreds of yards away. “In coastal areas, dolphins exchange whistles even when they're a third of a mile apart,” says Greg Campbell, who studies animals. That means dolphins shout out to group members that might be nearly five football fields away.

    What's amazing is who names the baby dolphin. Not the mother. Not an auntie dolphin or another group member. Scientists believe the baby dolphin itself comes up with the signature whistle. Like human babies, a baby dolphin plays with sounds throughout its first year. While testing its sound skills, a baby dolphin is doing something amazing. It's creating or figuring out its signature whistle. How or why it chooses its signature whistle is not clear. Studies show that most of the time the signature whistle is nothing like its mother's or group members' whistles.

    When the baby dolphin is about a year old, its signature whistle is set. It repeats it often so the other dolphins learn to recognize it.

    Deciphering(破译) dolphin names is just the beginning of figuring out what dolphins communicate about. Do they chat about sharks? Discuss the tides? Maybe they even have a name for people. Someday scientists are to decipher the rest of dolphins' communication.

    As we know, DNA testing is very useful for crime fighting. But now crime fighters could have a new tool at hand. Researchers have developed a cutting-edge (前沿的) technique to identify human hair. Their test is quicker than DNA analysis techniques currently used by the police.

    DNA testing is commonly used for identification because DNA is unique to each individual. However, environmental and chemical processes can degrade(降解) DNA, limiting its usefulness over time. Protein (蛋白质) in hair, on the other hand, is more stable than DNA but can also have variations (变异体) that may be unique to the individual.

     “Our analysis process can be used universally,” says Ms. Huang, “One of our samples even included dyed hair and the test was 100 per cent accurate. The test was able to distinguish East Asians, Caucasians and South Asians.”

    Dr. Beauchemin says she has got in touch with law enforcement agencies about using the new technology. She is also planning to collect more hair samples and continue her research with a goal of finding where exactly in the world hair sample is from, to look for more races and determine specific age.

     “We are in a very similar place with protein-based identification to where DNA testing was during the early days of development,” said chemist Brad Hart. “This method will be a game-changer, and while we've made a lot of progress toward improving it, there are steps to go before this new technique is able to reach its full potential.”

    Your glasses may someday replace your smartphone, and some New Yorkers are ready for the switch. Some in the city can't wait to try them on and use the maps and GPS that the futuristic eyewear is likely to include.

     “ I'd use it if I were hanging out with friends at 3 a. m. and going to the [bar and wanted to see what was open,” said Walter Choo, 40, of Fort Greene.

      The smartphone-like glasses will likely come out this year and cost between $250 and $600, the Times said, possibly including a variation of augmented(增强的) reality, a technology already available on smartphones and tablets (平板电脑) that overlays information onto the screen about one's surroundings. So, for example, if you were walking down a street, indicators would pop up showing you the nearest coffee shop or directions could be plotted out and come into view right on the sidewalk in front of you.

     “ As far as a mainstream consumer product, this just isn't something anybody needs,” said Sam Biddle, who writes for Gizmodo.com.  “ We're accustomed to having one thing in our pocket to do all these things,” he added, “and the average consumer isn't gonna be able to afford another device (装置) that's hundreds and hundreds of dollars.”

    9to5Google publisher Seth Weintraub, who has been reporting on the smartphone-like glasses since late last year, said he is confident that this type of wearable device will eventually be as common as smartphones.

     “It's just like smartphones 10 years ago,” Weintraub said. “A few people started getting emails on their phones, and people thought that was crazy. Same kind of thing. We see people bending their heads to look at their smartphones, and it's unnatural,” he said. “ There's gonna be improvements to that, and this a step there.”

    Could the device, smartphone or PC, which you are using affect the moral decisions you make when using it? To test it, researchers presented multiple dilemmas to a sample set of 1,010 people. The participants were assigned a device at random.

    One case of the questions participants were asked is the classic “trolley(有轨电车) problem”: A runaway trolley is headed towards five people tied up on a-set of train tracks. You can do nothing, resulting in the deaths of five people, or push a man off a bridge, which will stop the trolley. The practical response is to kill one man to save five lives, which 33. 5 percent of smartphone users chose, compared to 22.3 percent of PC users.

    “What we round in our study is that when people used a smartphone to view classic moral problems, they were more likely to make more unemotional, reasonable decisions when presented with a highly emotional dilemma, “Dr Albert Barque-Duran, the lead author of the study, told City, University of London. “This could be due to the increased time pressure often present with smartphones and also the increased psychological distance which can occur when we use such devices compared to PCs.”

    As for why the researchers started this study, Dr Barque-Duran noted, “Due to the fact that our social lives, work and even shopping take place online, it is important to think about how the contexts where we typically face moral decisions and are asked to engage in moral behavior have changed, and the impact this could have on the hundreds of millions of people who use such devices daily. “It's clear that we need more research on how our devices affect our moral decision making because we're using screens at an ever increasing rate.

    Every time your fingers touch your cell phone, they leave behind trace of amounts of chemicals. And each chemical offers clues to you and your activities. By studying them, scientists might be able to piece together a story about your recent life, a new study finds.

    A molecule (分子) is a group of atoms. It is the smallest amounts of some chemicals. Your skin is covered in molecules picked up by everything you touched. With each new thing your skin contacts, you leave behind some small share of what it'd touched earlier.

    Researchers at the University of California, San Diego (UCSD) recently studied such chemical leftovers on the phones of 39 volunteers. The study was led by biochemist Amina Bouslimani. To explore those residues (剩余物), the UCSD team wiped the surface of each volunteer's phone with a cotton swab (药签). The scientists also swabbed each person's right hand. Then the researchers compared the chemicals found on each cell phone.

    The scientists discovered as many of the molecules as they could. They then compared those to a database of chemicals. Pieter Dorrestein, a UCSD pharmaceutical chemist, had helped set up that database a few years earlier, which contains various substances, including spices, caffeine and medicines.

    Traces of everything from hundreds to thousands of different molecules turned up on each phone. The molecules suggested what had been in the body, and what each person had handled before touching the phone. From all these molecules, Bouslimani says, “We could tell if a person is likely female, uses high-end cosmetics (化妆品), colors her hair, drinks coffee, prefers beer over wine or likes spicy food.”

    Police already use molecular analyses to look for traces of explosives or illegal drugs. To date, Dorrestein says, he's never heard of police using phone residues to narrow down behaviour clues to search for a suspect. But detectives might one day use such data to track down someone who left a phone behind at a crime scene.

    A good modern newspaper is an extraordinary piece of reading. It is remarkable first for what it contains: the range of news from local crime to international politics, from sports to business to fashion to science, and the range of comment and special features as well, from editorial page to feature articles and interviews to criticism of books, art, theatre, and music.

    A newspaper is even more remarkable for the way one reads it: never completely, never straight through, but always by jumping from here to there, in and out, glancing at one piece, reading another article all the way through, reading just a few paragraphs of the next. A good modern newspaper offers a variety to attract many different readers, but far more than any one reader is interested in. What brings this variety together in one place is its topicality(时事性), its immediate relation to what is happening in your world and your locality now. But immediacy and the speed of production that goes with it mean also that much of what appears in a newspaper has no more than transient value.

    For all these reasons, no two people really read the same paper: what each person does is to put together, out of the pages of that day's paper, his own selection and sequence, his own newspaper. For all these reasons, reading newspapers efficiently, which means getting what you want from them without missing things you need but without wasting time, demands skill and self-awareness as you modify and apply the techniques of reading.