You can tell a lot about people by looking at their hair – not just whether they brush, spray or blow-dry. Scientists have found a way to use hair to figure out where a person is from and where that person has been. The finding could help solve crimes, among other useful applications.

    Water is central to the new technique. The liquid makes up more than half an adult human's body weight. Our bodies break water down into hydrogen(氢) and oxygen. Atoms of these two elements end up in our tissues, fingernails, and hair.

    But not all water is the same. Hydrogen and oxygen atoms can vary in how much they weigh. In the case of hydrogen, for example, there are three types according to their weights. Each type is called a hydrogen isotope（同位素）. And depending on where you live, tap water contains different isotopes.

    Can hair record this information? That's what James R. Ehleringer, an environmental chemist at the University of Utah, wondered. To find it out, he and his colleagues collected hair from hair stylists in 65 cities across the United States. Even though people drink a lot of bottled water these days, the researchers have found that people's hair has the same isotopes as found in local tap water. That's probably because people usually cook their food with the local water.

    Authorities can now use the information to analyze hair samples from criminals or crime victims and narrow their search for clues. For example, one hair sample used in Ehleringer's study came from a man who had moved from San Francisco to Salt Lake City. As his hair grew, it reflected his change in location.

    Standing desks have become common across Silicon Valley, offering health benefits to those willing to work on their feet. However, due to their high price, they have failed to catch on until now. Recently, Ikea has brought out Bekant convertible（可变换的） standing desk that can become a normal desk at the touch of a button. The $500 adjustable desk can transform from a standard desk to a standing one, and Ikea hopes it could make the standing desk mainstream.

    Experts say that changing from a seated to a standing desk can improve productivity. Similar desks have become a common sight at tech firms such as Google, where some employees have even installed treadmill (跑步机) and bicycle desks.

    The desk is not the first “convertible” on the market. As early as 2013, Stir Kinect brought out an adjustable desk. The $3,890 Stir Kinect desk has a motor to raise and lower itself, changing it into a standing desk or a traditional desk. The desk can even be programmed to move up and down slightly, making it appear to take a gentle breath to remind the user to change their positions. To move between sitting and standing positions, owners simply double tap on the screen. The desk can learn the user's preferences over time and suggest the best seating position.

The Stir Kinect desk was created by a team of ex-Apple and Disney engineers. It has a built-in touch screen to control and track movement, and can tell users exactly how many calories they burn by standing during their working day. It also has devices containing power points and USB ports for charging phones, to keep cables hidden.

    “Ikea's height-adjustable desk is great for opening up the lower end of the market, " said JP Labrosse, founder and CEO of Stir.

    People from East Asia tend to have more difficulty than those from Europe in distinguishing facial expressions — and a new report published online in Current Biology explains why.

    Rachael Jack, University of Glasgow researcher, said that rather than scanning evenly(均匀的) across a face as Westerners do, Easterners fix their attention on the eyes.

    "We show that Easterners and Westerners look at different face features to read facial expressions," Jack said. "Westerners look at the eyes and the mouth in equal measure, whereas Easterners favor the eyes and neglect (忽略) the mouth."

    According to Jack and her colleagues, the discovery shows that human communication of emotion is more complex than previously believed. As a result, facial expressions that had been considered universally recognizable cannot be used to reliably convey emotion in cross-cultural situations.

    The researchers studied cultural differences in the recognition of facial expressions by recording the eye movements of 13 Western Caucasian and 13 East Asian people while they observed pictures of expressive faces and put them into categories: happy, sad, surprised, fearful, disgusted, angry, or neutral. They compared how accurately participants read those facial expressions using their particular eye movement strategies.

    It turned out that Easterners focused much greater attention on the eyes and made significantly more errors than Westerners did. "The cultural difference in eye movements that they show is probably a reflection of cultural difference in facial expressions," Jack said. "Our data suggest that whereas Westerners use the whole face to convey emotion, Easterners use the eyes more and mouth less."

    In short, the data show that facial expressions are not universal signals of human emotion. From here on, examining how cultural factors have diversified these basic social skills will help our understanding of human emotion. Otherwise, when it comes to communicating emotions across cultures, Easterners and Westerners will find themselves lost in translation.

    Many people trying to sell homes find that an increase in home prices has turned the market in their favor. But sellers can still get the short end of the deal if they aren't careful. Here are a few tips for you:

    Don't test your luck. Of course you think anyone who moves into your lovely home should be willing to pay top dollars, especially if you've recently invested in some improvements. But listing a home at a price that's too high above the market price could turn away some buyers.

    Buyers noticing that the home which still hasn't been sold may begin to assume there's something wrong with the house and use that as a reasonable excuse for offering a lower price. And if a home hasn't received any offers after two weeks, it might be time to reset the price.

    A price that's too low can bring about an undesired outcome. Listing your home at or slightly below the market price can have the effect of drawing in a large group of buyers and increase the chances that a home will receive multiple offers. But setting the price too low comes with several risks. One possibility is that buyers will get skeptical of the home that is listed for $15,000 to $20,000 less than similar homes in the area, especially if it's not properly marketed. Once again, people might assume there is something wrong with the home and may not bother to look at it.

    Spy on the competition. Going to other people's open houses can give you a better sense of how your home compares with others on the market. Check out the decoration in their kitchens, the size of their backyards and use the information to figure out where your home should fit in the range of the price. But don't set your pricing just on what you see elsewhere.

    Chester is one of the best cities in the UK. As soon as you arrive in Chester you will appreciate the city's unique atmosphere and sense his history. Founded by the Romans over 2,000 years ago, much of the Roman influence remains and Chester's city walls are the most complete in Britain. Combined with history and heritage (遗产), Chester is a lively city full of bars, pubs, clubs, hotels, and restaurants for you to discover, attracting you to visit again and again.

    Travelling to Chester: Chester is easily accessible by many means of transport—whether you are travelling by rail, car, bus or plane. Please check our route planner below to help you plan your journey to Chester. Once you arrive in the city there are numerous car parks; however, during rush hours the easiest way to travel is by bus.

    Hotel: From bed & breakfast to the luxury of Chester's only five star hotel, Chester has all covered. Whether your trip is for business or pleasure, your room is just a click away!

    Sightseeing and Tours: The best way to see Chester is by a guided tour. If you join one, you still have a variety to choose from. Whether you choose the traditional guided walk, to be guided around Chester historical landmarks by bus or to take a boat down the River Dee, you will sure enjoy the delights of Chester.

As the world struggles to deal with the climate crisis, some companies are working to remove polluting carbon dioxide (CO₂) from the air. {#blank#}1{#/blank#}, but two US companies have recently made important progress.

Scientists say large amounts of CO₂ must be removed from the atmosphere and stored. {#blank#}2{#/blank#}. But there's so much CO₂ in the atmosphere that just planting trees and protecting forests won't solve the problem. In addition, when plants and trees die, the carbon they've stored gets released again.

That means humans need to come up with ways of removing carbon from the air and storing it. This is called Direct Air Capture (DAC). The science of removing carbon from the air is challenging, and it's still pretty new. Most DAC processes require a large amount of energy, {#blank#}3{#/blank#}.

A company called Heirloom has just opened the first DAC plant in the United States. The company heats up the limestone (石灰岩)to separate out the CO₂, which is then locked away in concrete (混凝土). The process is extremely expensive. {#blank#}4{#/blank#}. That's a tiny amount compared to how much carbon needs to be removed from the atmosphere, but the company says it hopes to remove a billion tons per year by 2035.

{#blank#}5{#/blank#}. Some people worry that it will take too long for DAC technology to become powerful enough to make a difference. Others worry that focusing on removing carbon could take attention away from more important climate actions, like switching from fossil fuel s to renewable energy. But experts say the decision isn't to do one or the other. The world needs to end fossil fuel use and pull carbon out of the air.

A. It's a huge and challenging goal

B. Plants and trees can do this naturally

C. Everyone is not excited about carbon removal

D. The new plant can remove 1,000 tons of CO₂ year

E. Graphyte is another US company working on DAC

F. and CO₂ is just a small part of the gasses that make up air

G. so one puzzle for these companies is how to remove carbon without creating more pollution