Your next Saturday night takeaway could be brought to you by a robot after a major food delivery company announced plans to use automated vehicles to transport meals. Europe's biggest online takeaway food company Just Eat has partnered with Starship Technologies to deliver food with robots on the streets of London later this month. “Nobody has ever done deliveries with land-based robots,” said Allan Martinson, the chief operating officer of Starship.

    The robot courier can travel up to 4 miles per hour for about 10 miles. It uses a GPS signal and nine cameras to navigate(确定方向). Instead of a person arriving at their door, customers could find themselves receiving a notification(通知) on their phone that says a robot is on its way and a code to unlock the automated courier. “Put the code in, the robot opens up, and there's your food,” said David Buttress, chief manager of Just Eat.

    The robot, which has so far been tested in Greenwich, Milton Keynes and Glastonbury, costs ￡1 to transport within 3 miles, compared with the ￡3 to ￡6 it costs for a human courier. To date 30 robots have driven nearly 5,000 miles without getting into an accident or finding themselves picked on by passers-by. They have driven in more than 40 cities around the world, including London and Tallinn, Estonia.

    An initial worry was how the public would react to robots. But Martinson said the public has been calm when passing the delivery machine on the streets. “The most surprising reaction has been the lack of reaction,” said Martinson.

    Another significant fear was that people would disrupt(扰乱) the robots, or try to steal them and their contents. To prevent this, the robot is fitted with nine cameras, two way audio, and movement sensors that send a warning if it is lifted off the ground. And it opens only with a pass code provided to the customer via a notification. “It's much easier to shoplift than it is to steal a robot,” said Martinson.

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    Women are friendly．But men are more competitive．Why? Researchers have found it's all down to the hormone oxytocin （荷尔蒙催生素）．Although known as the love hormone, it affects the sexes differently．

"Women tend to be social in their behavior．They often share with others．But men lend to be competitive．They are trying to improve their social status," said Professor Ryan．

    Generally, people believe that the hormone oxytocin is let out in our body in various social situations and our body creates a large amount of it during positive social interactions （互动） such as falling in love or giving birth．

But in a previous experiment Professor Ryan found that the hormone is also let out in our body during negative social interactions such as envy．

    Further researches showed that in men the hormone oxytocin improves the ability to recognize competitive relationships, but in women it raises the ability to recognize friendship．

Professor Ryan's recent experiment used 62 men and women aged 20 to 37．Half of the participants（参与者）received oxytocin．The other half received placebo （安慰剂）．

    After a week, the two groups switched with participants．They went through the same procedure with the other material．

    Following each treatment, they were shown some video pictures with different social interactions．Then they were asked to analyze the relationships by answering some questions．The questions were about telling friendship from competition．And their answers should be based on gestures, body language and facial expressions．

    The results indicated that, after treatment with oxytocin, men's ability to correctly recognize competitive relationships improved, but in women it was the ability to correctly recognize friendship that got better．

    Professor Ryan thus concluded: "Our experiment proves that the hormone oxytocin can raise people's abilities to better distinguish different social interactions．And the behavior differences between men and women are caused by biological factors （因素） that are mainly hormonal．"

    Think plants are just boring green things that you use for food and decoration? Think again! Plants are able to do some pretty awesome things that you're probably totally unaware of.

    Researchers have discovered that plants have the ability to communicate with an underground network made up of fungus (真菌) , which serves the plants in many ways. Tomato plants use the fungus web to warn each other of their own unhealthy conditions. Trees connected through the fungus network could move nutrients (养分) to and from each other. It is believed that larger trees move nutrients to smaller ones to help them to survive.

    Not only that, but they can also damage unwelcome plants by spreading poisonous chemicals through the fungus. It sounds like the plant world had the Internet before we did.

    Some plants have a rather impressive line of defense against being eaten. When sensing they are being swallowed, they give off a chemical into the air that attracts the insect's natural enemy. The enemy attacks the bug, thus saving the plants. This is basically the plant kingdom version of getting your older brother to beat up that kid who steals your lunch money.

    You might be aware that humans and animals have an internal clock. But did you know that plants also have this clock? This means they can prepare for certain times of day just like we do. Is it because they can react to light at sunrise? In a study, scientists found that plants use the sugars they produce to keep time, which help to regulate the genes responsible for the plant's own internal clock. So, in a sense, wake up with petunias (矮牵牛) is just as valid as ―wake up with the chickens.

    Nature is full of surprises. So for those of you who didn't know the wonders of plants, now you do.

    Eating red meat is linked to cancer and heart disease, but are the risks big enough to justify giving up juicy burgers and delicious steaks? Probably not, according to researchers who reviewed data from 12 clinical trials involving about 54,000 people. In a series of controversial papers, the researchers argue that the increased health risks tied to red meat are small and uncertain, and that cutting back likely wouldn't be worth it for people who enjoy meat.

    Those conclusions go against established medical advice. They were swiftly attacked by a group of famous U.S. scientists who took the unusual step of trying to stop the papers from being published until their criticisms were addressed.

    The new work does not say red or processed meats like hot dogs and bacon are healthy, or that people should eat more of them. The team's reviews of past studies generally support the ties to cancer, heart disease and other bad health outcomes. But the authors say the evidence is weak, and that there's not much certainty meat is really the cause, since other diet and lifestyle factors could be at play.

    If the latest example of how divisive nutrition research has become, with its uncertainties leaving the door open for conflicting advice. Critics say findings often aren't backed by strong evidence. Defenders counter that nutrition studies can rarely be conclusive because of the difficulty of measuring the effects of any single food, but that methods have improved.

    Based on their analyses, the researchers said people do not have to cut back for health reasons. But they noted that their own advice is weak, and acknowledged that they didn't consider factors such as animal welfare and the environment. Indeed, the case that meat production is bad for animal welfare and the environment is stronger than the case that it's bad for human health, according to an editorial that accompanies the report.

    Not all of the report authors agreed with its conclusions. Three of the 14 researchers said they support reducing red and processed meats. A coauthor of one of the reviews is also among those who called for a publication delay.

    Those who pushed to postpone publication also questioned why certain studies were included in the reviews while others were left out.

    As for his own diet, Dr. Gordon Guyatt, a member of the international research team that conducted the reviews, said he no longer thinks red or processed meats have significant health risks. But he said he still avoids them out of habit, and for animal welfare and environmental reasons.

Jack Horner is co-author of the book How to Build a Dinosaur. However, he is most famous for his role as consultant(顾问) on all four Jurassic Park films, including the new film Jurassic World.

The original film Jurassic Park tells the story of a theme park where dinosaurs live. In that movie, scientists used DNA collected by ancient mosquitoes that had been trapped in amber shortly after they drank dinosaur blood. The scientists used this dinosaur DNA to create baby dinosaurs. The scientists in Jurassic Park created various types of dinosaurs, but in the real world there is one big problem with the story. It turns out that DNA could not possibly survive the 65 million years since the death of the dinosaurs.

The new movie creates the Indominus Rex. This idea of creating a hybrid species is something Horner has explored before. In 2011, he gave a speech in which he discussed producing a dinosaur by working with the genes of a bird. Modern birds are the closest living relative of dinosaurs.

The concept of using the genes of different animals to create new animals is called transgenic science. And this type of science has already produced some interesting results — goats that produce spider silk in their milk, cows that produce proteins for medicines that can treat diseases, and a pig that produces less-polluting waste thanks to a bit of mouse DNA. However, none of these examples are close to the dinosaurs in Jurassic World. And for a good reason — genetics is a very complex science. Producing a new species is not as simple as just exchanging a few genes around.

In the end, Jurassic World is all about fun.

If you walk slowly through downtown Helsinki(赫尔辛基) during the day,taking in the splendid 19th century buildings,white boats and noise of passing trams(有轨电车),you will start to understand why it is called a city of two colours:white and blue.

The sea is always present in Helsinki.When you take a walk over the great open space of the central square,you will hear seabirds screaming.When you take the tram,suddenly and unexpectedly,you are faced with a calm,shining blue sea.You may notice that people in Helsinki do not rush about as in other cities.Instead,walk along the roads,politely letting other people by.

A usual way to see Helsinki for the first time is to start out by the boats.You will walk by the elderly women selling fish and vegetables in the market square and find yourself in front of a beautiful park.You may enjoy a pleasant walk in the park for a few hours and then take the tram.Trams are the perfect way to get around in Helsinki.Watching the old houses,parks,theatres,churches,shops,restaurants and people in the streets,you may have a slightly sad film feeling to it.

The pale summer nights are another wonder in the city.Following waterfront(滨水区) of the city after sunset,you couldn't help stopping and listening to the sweet silence,interrupted only by the screaming seabirds and leaving fishing boats.

However,in some way,Helsinki is also the most modern city in northern Europe.You will surely want to visit the white Glass Palace,the art museum,all those extremely popular cafes and design stores.