【推荐1】“You’ll get square eyes!” my mother used to say as I sat for hour after hour glued to the TV. I ignored her, of course. Past-forward a few decades and now I’m the parent. My 5-year-old lives in a world where screens aren’t fixed pieces of furniture. You can’t even avoid them by going outside. Screens are not only in our pockets; they’re everywhere.

The concerns have grown with the screens. In the past decade, we have heard that they will damage our mental health. Many of us feel more distracted by them, feeling guiltier and more tired as a result.

The apps and websites we can access on our phones have also sparked widespread concern. Big tech companies are also good at making use of our need for social recognition, hooking us on likes, retweets and follower counts. Social media has created a culture of mass narcissism (自恋), which has led many to worry about the emotional stresses on teenagers. A quick online search brings up dozens of papers linking screen use or social media with harmful effects on mental health, including depression and suicide.

Such statements are alarming. They are also widely believed, thanks to popular books like iGen by Jean Twenge, which claims that digital technology has ruined a generation. Yet, Amy Orben at the University of Oxford, who studies the impact of digital technology and social media in particular on mental health, holds different views. She claims that the underlying data can be used to tell different stories. She also spotted shortcomings in several large studies that claimed to show correlations (相关性) between the use of devices with screens and depression in users.

Twenge stands by her own finding, pointing in turn to what she considers flaws in Orben’s research methods. For David Max, at Royal College of Child Health in London, the effect of screen time and social media use on mental health remains speculative. “We cannot regard social media overall as good or bad,” says Davie. “We don’t know whether in individual cases social media is not responsible,” he says.

The explosion of mobile phone use has revolutionized our lives. I can download movies, write articles, communicate with my family and broadcast to the world all at the push of a button. Rather than impose constraints (限制), we should take a look at our use of screens and ask how they fit with the activities and lifestyle.

Every new technology with widespread impact has given rise to new fears. So the best bet may simply be to ask yourself what level of screen use makes you and those around you happy and try to stick to it. If you find yourself over addictive, don’t panic—and certainly don’t feel guilty. Nobody knows anything worth getting scared about.

【推荐2】An artificial intelligence chatbot (聊天机器人) called TacoBot from fast food chain Taco Bell now lets you order a meal in a smartphone text exchange that might look something like this:

TacoBot: Hello there. I’m your TacBot. I can help you order a meal for you or your team.

You: Can I order one soft taco (墨西哥煎玉米卷) with beef?

TacoBot: Sounds good. Do you want to keep adding stuff? Maybe some bacon?

Brands like Taco Bell and some tech companies are betting that more and more people will start using this conversational way of interacting online instead of clicking through on-screen menus.

If the trend catches on --- as firms like Facebook and Microsoft expect --- it could transform the digital landscape by allowing smartphone users to find information or make purchases with simple text messages, ignoring apps and search engines. Among the companies already developing or launching chatbots are the Wall Street Journal, CNN and retail giants Sephora and H&M.

“I believe we are headed to a shift where this will become one of the primary ways we interact with the digital world,” says Mark Beccue of Mark Beccue Consulting, who follows trends in the messaging market. “The chat user interface (界面) is what makes sense for a mobile-first world. You can be more specific and be quicker.”

Messaging services have become a natural place for chatbots to reside (居住), since their usage is growing: at least 1.4 billion people used a messaging app last year. According to Business Insider Intelligence, messaging apps have overtaken the largest social networks in the world.

The messaging service Kik meanwhile launched its own “bot shop”, with partners including retailers and game developers. Kik said the move was a response to the trend people using fewer apps and spending more time on chat platforms. “There’s nothing to download, no new registration required, and you can use an interface you’re already familiar with: chat,” Kik said in a statement.

However, some analysts remain skeptical on chatbots as the wave of the future. Jan Dawson of Jackdaw Research said the movement is largely driven by Microsoft and Facebook, two firms which would like a greater presence in mobile even though they don’t control the biggest smartphone operating systems. “There’s a lot of hype (炒作) around chatbots,” Dawson said.

Artificial intelligence has come a long way with systems like Apple’s Siri, Amazon’s Alexa and Microsoft’s Cortana, but still cannot deal with all possible situations, says Roger Kay of Endpoint Technologies Associates. “There’s a kind of hubris (自大) that someone could expand the one-to-many communication method to every human interaction,” Kay said.

【推荐3】Birds use vocalizations to attract mates, defend territories, and recognize fellow members of their species. But while we know a lot about how variations in vocalizations play out between populations of songbirds, it's far less clear how this variation affects birds such as penguins in which calls are inherited (遗传). A new study from The Auk: Ornithological Advances examines differences in the calls of Little Penguins from four colonies in Australia-night-time birds for whom vocalizations are more important than visual signals-and finds that differences in habitat, rather than geographic isolation (隔离) or other factors, seem to be the key driver of variation in the sounds these birds use to communicate.

Diane Colombelli-Negrel and Rachel Smale of Australia's Flinders University recorded calls from four Little Penguin populations across a small area of South Australia, one of which had previously been shown to have slight genetic differences from the other three, and used playback experiments to test penguins ability to distinguish between calls from different colonies.They found that agonistic calls, which are used in pair displays and aggressive situations, varied among the four populations, and that the calls' characteristics appeared to depend on small-scale differences in the habitat where the penguins lived. However, birds did not discriminate between calls originating from different colonies, which suggests that agonistic calls don't seem to play a role in isolating the two different genetic groups.

Penguins living in open habitats produced lower-frequency calls than those living in habitats with thicker vegetation-the opposite of the trend typically observed in songbirds. The authors think that agonistic calls may be subject to different selective pressures because they're used in close encounters with other birds rather than to communicate across distances, and could also be influenced by variation in the noise level of wind and surf.

“I was excited to find that in seabirds, as most of our knowledge in this area comes from studies on songbirds," says Colombelli-Negrel. "This new research suggests that many factors influence call variation in birds, which also depends on the function of the calls. This study highlights that many questions remain and that studies need to investigate more than one factor in conjunction with the function of the calls to fully understand call variation in seabirds.”

“This work tells an interesting story of vocal diversification in Little Penguins, and gives insight into how individual and micro-scale variation effects behavior," according to Stony Brook University's Heather Lynch, an expert on penguin calls who was not involved in the study. "Non-vocal-learning birds are relatively understudied in terms of vocalizations, and it is great to see penguin vocalizations being studied in such a way."