We considered a list of the best American books — but we'd need a whole issue to do them justice. Here are 5 that helped define the national character. Most from a century or so ago, they still entertain, teach and inspire American people.

    Moby-Dick by Herman Melville

    First published in 1851, the book tells the adventure stories of Captain Ahab and his continuous hunting for the white whale and draws us into a universe full of fascinating characters and stories.

    The Education of Henry Adams by Henry Adams

    Awarded the Pulitzer Prize in 1918, the book provides insight into Adams' family, including his experience as a private secretary to his father, minister to England during the American Civil War.

    Leaves of Grass by Walt Whiteman

    When Whiteman published Leaves of Grass in 1855, he wanted to define the American experience— sing for the new country in a new voice, reflecting the great changes in the American literary world that had taken place during his lifetime.

    Poems by Emily Dickinson

    An enthusiastic poet whose works have had a considerable influence on modern poetry, Dickinson's frequent use of dashes(破折号)，sporadic(零星的)capitalization of nouns, and unusual metaphors(隐喻) has contributed to her reputation as one of the most innovative poets of the 19^th-century American literature.

    The song of Hiawatha by Henry Wadsworth Longfellow

    First published in 1855, this is Longfellow's most popular and most recognized poem, showing the heroic life and death of a magic American Indian sent by the Great Spirit to guide the nations in the ways of peace.

    The online economy—from search to email to social media—is built in large part on the fact that consumers are willing to give away their data in exchange for products that are free and easy to use. The assumption behind this trade-off is that without giving up all that data, those products either couldn't be so good or would have to come at a cost.

    But a new working paper, released this week by Lesley Chiou of Occidental College and Catherine Tucker of MIT, suggests that the trade-off may not always be necessary. By studying the effects of privacy regulations in the EU, they attempted to measure whether the anonymization(匿名化) of search data hurts the quality of search results.

    Most search engines capture user data, including IP addresses and other data that can identify a user across multiple visits. This data allows them search companies to improve their algorithms(算法) and to personalize results for the user. At least, that's the idea. To determine whether storage of users' personal data improves search results, Chiou and Tucker looked at how search results from Bring and Yahoo differed before and after changes in the European Commission's rules on data retention(数据保存). In 2008 the Commission recommended that search engines reduce the period over which search engines kept user records. In response, Yahoo decided to strengthen its privacy policy by anonymizing user data after 90 days. In 2010 Microsoft changed its policy, and began deleting IP addresses associated with searches on Bring after six months and all data points intended to identify a user across visits after 18 months. In 2011 Yahoo changed its policy again, this time deciding to store personal data longer—for 18 months rather than 90 days—allowing the researchers yet another chance to measure how changes in data storage affected search results.

    The researchers then looked at data from UK residents' web history before and after the changes. To measure search quality, they looked at the number of repeated searches, a signal of dissatisfaction with search results. In all three cases, they found no statistically significant effect on search result quality following changes in data retention policy. In other words, the decision to anonymize the data didn't appear to impair the search experience. “Our results suggest that the costs of privacy may be lower than currently perceived,” the authors write, though they note that previous studies have come to different conclusions.

    Do you find it difficult to put down your mobile phone?

    If yes, you're not alone. These days, many people suffer from the stress of FOMO (fear of missing out). They reach of their mobile phones when they wake up in the morning, and for the rest of the day, they constantly check their social media apps for the latest updates.

    Despite the convenience smart phones bring, many people struggle with their digital habits. This is why Google introduced an app called Dashboard for Android operating system. This new app includes well-being functions that aim to help users manage the time they spend on their digital devices.

    It all starts with a bird's-eye view. Dashboard allows users to look at all the details of their phone habits. For example, a user can see how many times they're unlocked their phone and how many times they're checked their social media apps, as well as how much time they spend on each app every day.

    Once the users see this information, they'll be able to make some changes. With the App Timer function, users can set a time limit for how long they can use each app for every day.

    But even if users become more mindful of their usage, they're still likely to be drawn in by notification（通知）. Such feature automatically（自动地）silences incoming calls and notifications when a user puts their phone face down.

    If people truly want to make full use of their free time instead of losing hours using their smart phones, these new functions are just one way of doing that.

    The easiest answer would be just to use your willpower.

    Most groups of plants and animals are richer in species and more plentiful near the equator. In the ocean, that holds true for cold-blooded predators(掠食者). But warm-blooded predators are more diverse toward the poles and noticeably missing from several warm hot spots. Why?

    John Grady, an ecologist, and his team considered the possibility—warm-blooded animals need a lot to fuel their metabolism(新陈代谢). Perhaps colder waters are just richer in small fish? But they found that at higher, colder places, there isn't actually much more food around. It's more that warm-blooded animals are eating a much bigger share of it than their cold-blooded competitors.

    The real explanation is simple. An animal's speed, swiftness, and intelligence depend on its metabolism, which in turn depends on its temperature. Since birds and mammals can keep heating their bodies in icy conditions, they remain fast and attentive. By contrast, the fish they hunt become slower and duller. At some tipping point of temperature, seals, dolphins, and penguins start out swimming their prey(猎物). They become more likely to come upon targets and outpace the cold-blooded predators of their own.

    In Grady's words, "Warm-bodied predators are favoured where preys are slow, stupid and cold." That's why sharks and other predatory fish dominate near the equator, but colder waters are the kingdom of whales and seals. By keeping food to themselves in the poles, these creatures can then specialize on specific types of prey, which makes them more likely to split into separate species. The killer whales of the North Pacific, for example, include mammal-eating transients and fish-eating, year-round residents.

    But the world is changing. It's likely that the surface of the oceans will warm by 2 to 3℃ within this century. Grady's team estimates that every time the ocean's surface warms by 1℃, populations of sea mammals will fall by 12%, and populations of seals and sea lions will fall by 24%.

    But "predictions are hard," Donna Hauser from the University of Alaska Fairbanks notes. "Polar bears are losers of a warming world, but some populations are still doing well. Some groups of whales have changed the timing of their migrations; others are hunting in deeper, colder waters. These changes might make sea mammals more adaptable to changing climates. Maybe they just need to find the places where fish remain slow, stupid and cold."

    Living abroad to study can certainly be an interesting experience but is that alone a good enough reason for spending years far away from home? To make the experience truly worthwhile, there has to be a goal behind the decision to study abroad. This may be a wish to perfect language skills in a foreign language environment, or a clever move in your career development. You must also consider the costs, not just of living and studying abroad, but of applying. Most universities now charge application fees for international students.

    If after considering these points you are sure that you want to apply to study abroad, your next step is to choose the right programme of studies. Research your choices and select carefully. You must do your homework well. Most universities have information online but you can also email and ask them to send you more details. You can find a lot of information on school ranking from education websites. But read carefully. Different universities emphasize different strengths. Don't just think about the university's reputation; look for the most suitable for your goals.

    Next, you must deal with a large pile of paperwork. This involves filling in application forms, preparing your school records, and getting reference letters. Reading the instructions and requirements of the universities carefully is of great importance. Sadly, many fine applicants get kicked out in the first round, simply because they don't follow the application procedure properly.

    Money is another important consideration. Some scholarships are provided by governments, others by schools and colleges. This information, again, can be found on the Internet. If you find a scholarship that is suitable for you, follow the application procedure carefully; the earlier you apply, the better your chance of getting it.

    Huawei Technologies Co. displayed its much-anticipated in-house operating system Harmony OS on Friday, marking what some call the Chinese tech giant's biggest push yet to build its own software ecosystem for the era of the internet of things.

    The move is also expected to weaken the influence of the United States government's restrictions on Huawei using Google's Android operating system in smartphones, analysts said.

    Yu Chengdong, CEO of Huawei's consumer business group, speaking in Dongguan, Guangdong province, said it is difficult to deliver a smooth experience across different devices with the huge amount of codes involved in the Android and Linux operating systems. Linux is an open-source operating system widely used in personal computers and other hardware.

    "Harmony is a next-generation operating system designed to address the challenge," Yu said, adding that it will be able to support a wide range of application situations, including smart TVs, automobiles and wearables.

    The internet of things refers to a network of devices and other objects that can connect with each other and exchange data.

    Yu said the US government's restrictions have accelerated the company's marketing of the system, which now has about 4,000 employees working on it.

    The senior executive said Harmony can be used in its smartphones. But Android is still Huawei's preferred choice for handsets if the company is allowed to use it.

    "But when Android is not available, Harmony can be applied immediately to smartphones. Harmony is ready," Yu added.

    Jia Mo, an analyst at market research company Canalys, said even if Huawei does not use Harmony in its smartphones in the short term, its smartwatches and smart TVs can be equipped with Harmony to widen its use and accumulate more experience in building an ecosystem.

    "Also, more importantly, Huawei chose to build Harmony into an open-source operating system and allow it to be compatible with Android. Thus Harmony will be more accepted by current Android users. This will prevent Huawei from repeating the fate of Microsoft in promoting smartphone systems," Jia said. Microsoft failed to popularize the use of its Windows system in smartphones years ago.