The streams are about 12 to 15 feet wide and 300 feet or more long, scientists said. "What we're dealing with is wet soil, thin layers of wet soil, not standing water," said Aifred  McEwen of the University of Arizona at Tueson! the principal scientist for the Mars Reconnaissance Orbiter's high-resolution imaging experiment,

     Because liquid water is essential to life, the findings could have major implications for the possibility of Martianlife, There searchers said further exploration is needed to determine whether microscopic life exists on the planet.

    The presence of liquid water could also make life easier for astronauts visiting or living on Mars. Watercould be used for drinking and for creating oxygen and rocket fuel. NASA's goal is to send humans there inthe 2030s.

    The evidence of flowing water consistslargely of dark, narrow streaks(条痕) on the surface that tend to appear and growd uring the warmest Martian months and fade the rest of the year.

    Mars is extremely cold even in summer,and the streaks are in places where the temperature is as low as minus 10 degrees Fahrenheit. But salt can lower the freezing point of water and melt ice.

    The source of the water is a mystery. Scientists noted it could be melting ice. It could be an underground a quifer, which is rock or sand that can hold water. It is possibly water vapor from the thin Martian atmosphere, Or it may be a combination Michael Meyer, lead scientistfor NASA's Mars exploration program, said the only definitive way for now to determine whether there's life on Mars is to collect rocks and soil foranalysis on Earth - something a U.S. lander set for lift-off in 2020 will do.

    A Japanese company, Next Technology, has created a robot dog that can tell you how bad your feet smell, by using a powerful sensor fixed in its nose. If you feet don't have a bad smell. Hana-chan will happily wag its tail, if it's exposed to feet that are mildly smelly, it'll start to bark, and if they give off an extremely bad smell, it'll just fall over like the smell caused it to faint(昏倒).

    Foot odor (脚臭) is a big deal in Japan, where it's a custom for people to take off their shoes whenever they enter someone's home. In fact, exposing others to bodily odors can be considered annoyance in Japan. Some of the most brilliant minds in the country's tech industry have been trying to solve this problem. Last year, Thanko started selling axmpit (腋窝) fans designed to keep people's armpits nice and dry Now, we have Hana-chan.

    The robot dog has a special sensor for a nose, and can tell you if your feet smell just by sniffing them for a few seconds. According to some media reports, Hana-chan can help solve the problem of extremely smelly feet by spraying them with air freshener, but it's unclear whether this feature comes built-in, or if you'll have to pay extra for it.

    According to researchers at NextTechnology, the idea for Hana-chan was inspired by a person who desperately wanted some way to know if his feet smelled. "He told us his daughter had said his feet were smelly, " NextTechnology's Kimika Tsuji said. “But he didn't want to know how bad the odor was because he would feel hurt. That's why we developed this cute robot. "

    You may be able to make Hana-chan faint with your smelly feet, but it can have the same effect on budget-conscious people. NextTechnology plans to start selling the feet-smelling robot dog for ￥100, 000 ($9, 280) next May.

    Japan has made a lot of noise in recent years about removing the traditional view that women should stay at home while men go out to work. So it was shocking when, on August 7th, Tokyo Medical University (TMU), a distinguished medical school, admitted marking down the test scores of female applicants to keep the ratio of women in each class below 30%.

    Their defence was that women are more likely to drop out to marry and have children. To judge female applicants to medical school purely on their academic performance would leave Japan with a shortage of doctors, they said. The admission has caused outrage.

    "Doctoring has long been a male field. But it is not the only one. Discrimination is common in banks and trading firms, where stamina (耐力) and loyalty, qualities somehow associated with men, are prized," says Mari Miura, a political scientist at Sophia University. All this embarrasses a government that has promised to make women "shine". The policy seems based on the need for more workers rather than on genuine concern for women.

    Shinzo Abe, the prime minister, says he wants to bring millions more women into the workforce to make up for a labour shortfall caused by its ageing and declining population. In the field of politics, the record under Mr. Abe's premiership (首相任期) is disappointing. Just two members of his 20-strong cabinet are women, including Seiko Noda, in charge of women's rights. Ms. Noda, who makes little secret of her ambition to beat Mr. Abe in a leadership contest next month, has just published a book called "Grab the Future", her public declaration for pulling Japan into line with "global standards". She has almost no chance of winning.

    Hacking isn't just for computers and smartphones, According to a study published last week in the journal Science, scientists have found a way to hack a plant's genes in order to make it use sunlight more quickly. Someday, the results could increase the amount of food produced around the world.

    Photosynthesis（光合作用）is the word used to describe how plants use sunlight, water, and carbon dioxide to make their own food. Scientists who conducted the new study say this is a very slow process. Plants use less than 1 percent of the energy available to therm. But by hacking a plant's genes, the scientists were able to increase the amount of leaf growth on plants between 14 and 20 percent.

    "Specifically, scientists hacked the plant's protective system. Normally, this system is activated when a plant gets too much sunlight, "said scientist Krishna Niyogi, co-author of the study. When the plant senses the light, it gets rid of extra energy and creates more leaves. When the plant is in shade, the protective system is turned off, but the process is slow.

    Stephen Long is the lead author of the study. He compared a plant's protective system to light-adjusting glasses. When a person wears the glasses outside during the day, the lenses（镜片）darken and lighten depending on how sunny it is. Plants do the same thing, he said. But in plants the adjustment can take anywhere from 10 minutes to an hour. This makes it hard for plants to get the right amount of sunlight needed to create food.

    The new study sped up the process. By changing the plant's genes, the protective system turned on and off more quickly than normal. As a result, leaf growth on the plants scientists used in the study increased. Leaf growth in two plants increased by 20 percent, while leaf growth on a third plant increased by 14 percent. Scientists conducted the study on tobacco plants. But they think the genetic changes will produce the same results in corn and rice.

    Fish have different personalities which change as they experience life's highs and lows, according to British biologists.

    Researchers identified different "personalities" in their fish by observing the boldness(大胆) or shyness of individuals, according to The Nature. Like people, some fish are very confident in the face of novelty or conflict, while others are silent and fearful.

    The scientists selected particularly bold and shy rainbow trout(虹鳟鱼), and tested whether they changed their outlook depending on what life threw at them. They arranged some fish to fight and others to watch to see how both the participants and observers responded to victories and defeats. Winning or losing a fight, or even watching fellow fish overcome the difficulties influenced the future behavior of the creatures studied in the lab.

    The researchers made fish compete with much larger or smaller opponents(对手), to ensure that they would win or lose their fights. These bold fish that won their fights tended to be even bolder when later presented with a novel food item; losing their fight caused them to be much more cautious.

    Fish also learn by watching others. Bold fish watching a shy fish exploring a mystery object were much more nervous when later given a novel item for themselves.

    Predictably, shy fish that won a fight also gained more confidence, but surprisingly, shy fish that lost their fights also grew bolder when exploring strange new food, Sneddon said, adding that this could be due to what she calls a "desperado effect"(亡命徒效应).

    The new research suggests that animals can gradually adapt(使适应) their personalities. The results agree with the effects that life experience can have on humans.

    It can be tough to pull kids away from their computers and mobile devices these days. While they're playing games, wouldn't it be great if they could be learning at the same time? Good educational apps offer fun challenges that teach specific grade - level skills. Here are four that combine fun and learning.

    Understanding Math ( $ 3.99 ； iOS)

    Understanding Math goes beyond basic comprehension to gain a deeper understanding of the whys and how's of math. The app tracks your child's progress to determine strengths and weaknesses in different skill areas, and you can customize (订制) your child's learning experience to suit the needs.

    Word Creativity Kit ( $2.99； iOS)

    Word Creativity Kit aims not only to make creative writing fun but also build up grammar rules. The app presents a series of words from seven categories, such as space or fantasy. Kids add their own words to finish the complete thoughts that these words have inspired.

    Barefoot World Atlas ( $4.99； iOS)

    Barefoot World Atlas helps kids learn about geography and world cultures with a touch of the screen. Each region features a set of sub – topics, from wildlife and natural features to native people, landmarks, and architecture. These facts and illustrations are delivered in photographs, sounds, and hundreds of mini videos.

    My Grades & Homework ( $0.99； iOS)

    A combination of grades and homework tracker, My Grades & Homework can help your child stay organized and on top of the progress in school. A convenient calendar and course list format and offer a glance at your child's assignment schedule that he or she might not normally get from standard homework planners.