Millions of people along the US mid-Atlantic region should be preparing for severe snow, the National Weather Service has said. Forecasters say two feet of snow could fall over the weekend in some areas. A light dusting of snow on Wednesday night caused a traffic jam in Washington, but it is what lies ahead that is occupying the thoughts of millions of people living on the US east coast.

    Washington Mayor Muriel Bowser tweeted an apology to her constituents(选民), saying that the city government had “failed to use the necessary resources effectively in response to the snow-for that I am sorry.” Among those affected was President Barack Obama, whose motorcade spent an hour and 12 minutes trying to get him from an airport back to the White House-a trip that typically takes about a half hour.

    Routine commutes lasted up to three hours and some people abandoned their cars, after an inch fell-a small amount compared to what is expected on Friday and Saturday. Long queues have formed at supermarkets, as people expect shop closures over the weekend. “Heavy snow and blowing snow will cause dangerous conditions and will be threat to life and property,” the National Weather Service warned.

    Across the US east coast at a glance:

    Classes were cancelled at schools in Kentucky and Tennessee, the first states being affected by the storm.

    Washington has requested Humvees from the National Guard so that emergency responders can reach isolated(孤立的) people and places. Besides, its underground train system will close throughout the weekend.

    West Virginia Govemor Earl Ray Tomblin has activated the National Guard to assist.

    In Philadelphia, Pennsylvania officials are calling on people to keep large salt stockpiles and plough vehicles in good repair.

    Sports shoes that work out whether their owner has done enough exercise to warrant(保证；授权) time in front of the television have been invented in the UK.

    The shoes — named Square Eyes — contain an electronic pressure sensor and a tiny computer chip to record how many steps the wearer has taken in a day. A wireless transmitter(传话器) passes the information to a receiver connected to a television, and this decides how much evening viewing time the wearer deserves, based on the day's efforts.

    The design was inspired by a desire to fight against the rapidly ballooning waistlines among British teenagers, says Gillian Swan, who developed Square Eyes as a final year design project at Brunel University to London, UK. “We looked at current issues and childhood overweight really stood out,” she says. “And I wanted to deal with that with my design.”

    Once a child has used up their daily allowance gained through exercise, the television automatically switches off. And further time in front of the TV can only be earned through more steps.

    Swan calculated how exercise should translate to television time using the recommended daily amounts of both. Health experts suggest that a child take 12,000 steps each day and watch no more than two hours of television. So, every 100 steps recorded by the Square Eyes shoes equals exactly one minute of TV time.

    Existing pedometers(计步器) normally clip(夹在) onto a belt or slip into a pocket and keep count of steps by measuring sudden movement. Swan says these can be easily tricked into recording steps through shaking. But her shoe has been built to be harder for lazy teenagers to cheat. “It is possible, but it would be a lot of effort,” she says. “That was one of my main design considerations.”

    In the near future, we may be using our eyes to operate our smart-phones and tablets, even when it comes to playing popular games like Fruit Ninja.

    The Gaze Group has been developing eye-controlled computer technology for nearly 20years. But those devices have been firstly designed to help those with disabilities, and are very expensive.

    “After a while, we figured out that probably the best way is to go for a mass-market way,”says Gaze's Sune Alstrup Johansen. “Where everybody would have this available.”

    Johansen and some of his colleagues have formed a new company, the Eye Tribe, which is hoping to develop the technology on a mass commercial level.

    The technology works when combined with the computing device toward the user's face. After making sure of the user's eye movements, the technology is then able to easily find where a person's eyes are moving, and then allow the eyes to control a cursor (光标)

    “Our software can then determine the location of the eyes and know where you're looking on the screen to make sure what you're looking at, ”reads an explanation on the Eye Tribe site.

    There has been a gradual change toward hands-free technology in recent years, particularly in the gaming world. Recently Xbox released the Kinect device, which lets users control their Xbox and play certain games using only their hands, legs and voices. But still, most of these devices have been more of a gimmick than a practical way to use one's hands to control a mobile device. Johansen said a replaceable filter (滤光器) would be a cheap, convenient way for most consumers.

    And even as companies like The Eye Tribe work to create such a product for the average user, making the eye-controlled technology more accessible and less expensive will have similar benefits for physically disabled users.

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    A strange object was found in a small city called Carlos Spegazzini, just a short drive from the capital city of Buenos Aires.

    When farmer Jose first found an odd scene in his farmland, he began to dig at the object. However, he quickly found himself running to tell his wife. Jose needed more support if he was going to investigate this strange thing.

    Even the dog was hesitant to investigate. Unfamiliar with the object, man's best friend was not about to jump at it with little concern. Therefore, they chose to call in somebody who has a better idea of what to do.

    When the police first showed up, they were just as stumped as Jose. They knew this object was something out of the ordinary. It might even be something extraordinary, so more questions appeared.

    It quickly became apparent, it was time to call in the big guys. That's right; when you find something that appears to be out-of-this-world, it's time to call in those who study the mysteries of the old world.

    Authorities called in archaeologists who jumped at the chance to study the object. They quickly determined one thing was for certain: the ancient big one that left this behind was absolutely massive! The group was unable to move the shell, as it weighed nearly two tons!

    Clearly, this massive beast was not the only of its kind existing in the modem-day world. Similar fossils had been found in the surrounding areas and had even made their way to museums. But what was the ancient beast?

    A pretty face is never forgotten. Do you believe so? But maybe it is untrue! Psychologists believe beautiful people are less likely to be recognized. A new study suggests that attractiveness can actually prevent the recognition of faces, unless a pretty face has particularly distinctive features, such as Angelina Jolie's.

    German psychologists think the recognition of pretty faces is distorted (扭曲) by emotions. Researchers Holger Wiese, Carolin Altmann and Stefan Schweinberger at the University of Jena, Germany, discovered in a study that photos of unattractive people were more easily remembered than pretty ones when they showed them to a group of people.

    For the study, which was published in science magazine Neuropsychologia, the psychologists showed photos of faces to test subjects. Half of the faces were considered to be more attractive and the other half as less attractive, but all of them were being thought of as similarly distinctive looking. The test subjects were shown the faces for just a few seconds to memorize them and were shown them again during the test so that they could decide if they recognized them or not.

    The researchers were surprised by the result. “Until now we assumed that it was generally easier to memorize faces which are being considered as attractive, just because we prefer looking at beautiful faces,” Dr. Wiese said. But the study showed that such a connection cannot be easily proven. He assumes that remembering pretty faces is distorted by emotional influences, which enhance the sense of recognition at a later time. The researchers' idea is backed up by evidence from EEG-recordings (脑电图记录) they used during their experiment which show the brains' electric activity.

    The study also revealed that in the case of attractive faces, considerably more false positive results were detected. In other words, people thought they recognized a face without having seen it before. “We obviously tend to believe that we recognize a face just because we find it attractive.” Dr. Wiese said.

    The world is a greener place than it was 20 years ago. A study published in the journal “Nature Sustainability” said that recent satellite data reveals a greening pattern that is strikingly prominent in China and India. The study shows that human activity in China and India dominates this greening of the planet, thanks to tree planting and agriculture. The effect comes mostly from ambitious tree-planting programs in China and intensive agriculture in both countries.

    “China and India account for one-third of the greening,” said lead author Chi Chen of Boston University. “ That is a surprising finding, considering the vague idea of land degradation (毁坏) in populous countries from overexploitation,” added Chen.

    China alone accounts for 25 percent of the global net increase in leaf area with only 6.6 percent of global vegetated area. The greening in China is from forests (42 percent) and croplands (32 percent), but in India, it is mostly from croplands (82 percent) with minor contribution from forests (4.4 percent).

    China's outsized contribution to the global greening trend comes in large part from its programs to conserve and expand forests with the goal of preventing land degradation, air pollution, and climate change.

    “Once people realize there is a problem, they tend to fix it,” said Rama Nemani, research scientist and co-author of the study. “In the 1970s and 80s in India and China, the situation around vegetation loss was not good. In the 1990s, people realized it, and today things have improved. Now we see that humans are contributing.”

    Land area used to grow crops is comparable in China and India—more than 770, 000 square miles—and has not changed much since the early 2000s. Yet these regions have greatly increased both their annual total green leaf area and their food production.

    This was achieved through multiple cropping practices, where a field is replanted to produce another harvest several times a year. Production of grains, vegetables, fruits and more have increased by about 35%～40% since 2000 to feed their large populations.