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．"

    Animal lovers have long suspected that playing with pups was good for the soul, and now science has confirmed it – for students in particular.

    The results of a new study done by researchers at the University of British Columbia concluded that the college students who spent time at drop-in dog therapy sessions experienced an increase in feelings of wellness and a reduction in overall stress. The study, as reported by Science Daily, indicates that playing with pups is not only popular with the students, it's also beneficial to their health. This finding was seen across gender（性别）.

    The study, which published on March 12 in the journal Stress and Health, involved 246 students who were surveyed before and after they dropped by dog therapy sessions. The young participants were given free access to pet, hug with and talk to seven to 12 therapy dogs. Additionally, they filled out questionnaires right before and right after hanging with the dogs, as well as 10 hours later.

    According to researchers, these young adults reported a notable increase in happiness, a significant reduction in stress and a flood of energy right after their sessions with the pups. Although the reported feelings of happiness and satisfaction weren't long-lasting, researchers say other effects have clear, positive advantages.

    “These sessions clearly provide benefits for students in the short-term, so we think universities should try to schedule them during particularly stressful times, such as around exam periods,” Assistant Professor of Psychology at UBC and the study's senior author, Frances Chen told Science Daily. “Even having therapy dogs around while students are working on their out-of-class assignments could be helpful.”

    While elephants born without tusks (长牙)are not unheard of，they normally form just 2 to 6 percent of the population. However, that is not the case at Mozambique's Gorongosa National Park, where an astonishing 33 percent of female elephants born after the country's civil war ended in 1992 are tuskless. While that may appear to be just a coincidence, Joyce Poole, an elephant behavior expert, has another theory. The researcher thinks we may be witnessing unnatural evolution of the species due to the constant hunting of elephants for valuable ivory.

    Poole says before the country's 15-year-long civil war, the 100,000-acre park was home to over 4,000 elephants. However, by the time the conflict ended in 1992, about 90 percent of them had been killed for ivory to help finance weapons (武器)and meat to feed the soldiers. Of the less than 200 survivors, over 50 percent of adult females had no tusks. Therefore, it is not surprising that the park's tuskless elephant population has grown greatly.

    This is not the first time researchers have observed a great change in the population of elephants. At Zambia's South Luangwa National Park and Lupande Game Management Area， areas which were heavily hunted in the 1970s and 1980s, 35% of elephants 25 years or older and 13% of those younger than 25 are now without tusks. A 2008 study published found that the number of tuskless females at the Ruaha National Park in Tanzania went from 10.5 percent in 1969 to almost 40 percent in 1989, largely due to illegal hunting for ivory.

    The recent ban on ivory in both the US and China should help get rid of, or at least reduce, elephant hunting. However, scientists are not sure how long it will take for elephants with a higher rate of tuskless females, to change the trend.

    The New York See It All Tour is exactly what it sounds like: an all-inclusive guided tour of New York City.

    Central Park

    One of the most famous parks in the world, Central Park is a man-made wonder. Not only is it the first public park built in America, but it is also one of the most frequently visited parks, with over 25 million guests per year. Set in the middle of busy Manhattan, its grounds serve as a safe harbor, not only for athletes, and musicians but also for lots of migratory birds each year. One can spend an entire peaceful day wandering its grounds, gazing upon nearly 50 fountains, monuments, and sculptures or admiring its 36 bridges.

    Hudson River Park

    Hudson River Park is a waterside park on the Hudson River that extends from 59th Street south to Battery Park in the New York City district of Manhattan. Bicycle and pedestrian paths, including the Manhattan Waterfront Greenway, span the park north to south, opening up the waterfront for the public to relax. The park includes tennis and soccer fields, children's playground, dog run, and many other features.

    Washington Square Park

    Washington Square Park, located in the heart of Greenwich Village, is a very popular and often crowded square. People from all backgrounds gather to this large square dotted with trees.

    Central Park Zoo

    The Central Park Zoo is a small 6.5-acre zoo located on Central Park in New York City. The zoo began in the 1860s, making it the first official zoo to open in New York. The zoo was improved in 1934, with the addition of many new buildings ranged in a quadrangle around the sea lion pool. Finally, the zoo was repaired in the mid-1980s and reopened in 1988, replacing the old-fashioned cages with naturalistic environments.

    Researchers at the University of Chicago have trained an artificial intelligence system, to write fake reviews on Yelp, a website showing customers reviews on shopping or something else, and it's pretty hard to tell them apart from a human review.

    Their study, which will be presented at the ACM Conference on Computer and Communications Security in October, aimed to throw attention onto how easily these systems can write reviews like humans and how damaging they can become if they're not monitored properly.

    Since many small businesses rely on online reviews to help grow and keep their reputation, a future where someone—like a rival or angry customer—could crazily fill their page with negative reviews written by a machine is pretty worrying.

    And, according to the research team, the threat goes far beyond a bunch of fake reviews on Yelp. "In general the threat is bigger," Ben Y. Zhao, one of the authors of the study, said. "I think the threat towards society is large and it really misleads users and shakes our belief in what is real and what is not. I think that's going to be even unimaginable."

    To test how believable these reviews came across, the researchers invited 40 volunteers and had AI generate five fake reviews for 40 actual restaurants. The volunteers were asked how useful they thought the review was and whether or not they thought it was fake. The AI reviews ranked as "effectively indistinguishable" from real reviews，according to the study. Further, the fake reviews were given a 3.15 "usefulness" rating, compared to a 3.28 rating for human reviews.

Anyone who has never been to China Braille Library will draw to mind various images of the place.They would wonder how the library works all the way.In fact, the library offers readers a pleasant space with several broad reading rooms on the third floor,and has 18,269 kinds of books, including 3,523 kinds of braille books, 809 kinds of braille journals, 419 kinds of books written in both braille and visible language, and 142 kinds of children's ordinary books.

The library is open to the 17 million visually impaired people in China. This library has an arrangement with China Post, under which it has manufactured a special kind of mailing bag with cards where the address of the library is printed on one side.The borrowers can make phone calls, or send WeChat messages or emails to the librarian, listing the books they are seeking. The librarian then fishes out these books, puts them into the mailing bag, fills in the address of the borrower on the other side of the card and waits for a postman to pick up the bag.Whenever the borrower finishes reading, he or she needs to put the books back into the bag, turn the address card around and put it into a postbox for the books to return to the library.

In the age of multimedia, books have taken various forms. That applies to the world of the visually impaired, too.CBL offers its readers a smart listening device that looks like an old-fashioned cellphone. Guided by a recorded voice, a user has to just press a few buttons to gain access to 20 terabytes of audiobooks stored on the CBL website.The smart listening device is part of a Digital Reading Project for the Blind launched by China Disabled Persons' Federation in 2017.

As part of the program, the government purchased 200,000 such devices and distributed them to the over 400 Braille libraries and barrier-free reading rooms nationwide for lending to the visually impaired. Now, 80 percent of them are still in use, which means more than 160,000 visually impaired people are benefiting from it.