1 . While screen time is known to affect sleep, new research suggests that interactive (互动的) activities, such as texting friends or playing video games, put off and reduce the time spent asleep to a greater degree than passive (被动的) screen time like watching television, especially for teens.

The team studied the daytime screen-based activities of 475 teenagers using daily surveys. They asked the teens how many hours they had spent that day communicating with friends through social media and how many hours they spent playing video games, surfing the internet and watching television or videos. Finally, the researchers asked if they had joined in any of these activities in the hour before bed.

Next, the team measured their sleep time for one week. The researchers found that the teens spent an average of two hours per day communicating with friends via social media, about 1.3 hours playing video games, less than an hour surfing the internet and about 1.7 hours watching television or videos. For every hour throughout the day that they used screens to communicate with friends, they fell asleep about 11 minutes later averagely. For every hour to play video games, they fell asleep about 9 minutes later. Those who talked, texted or played games in the hour before bed lost the most sleep: about 30 minutes later.

Interestingly, David, lead author of the study, said the team found no obvious relations between passive screen-based activities and sleep. “It could be that passive activities are less mentally exciting than interactive activities,” said Anne, co-author of the study. “It’s a tricky situation,” she said. “These screen tools are really important to everyone nowadays, so it’s hard to put a limit on them, but if you’re really looking out for a teenager’s health and well-being, you might consider limiting the more interactive activities, especially in the hour before bed.”

2 . Moving around Bogota can be a bit of a Jekyll-or-Hyde experience. On the one hand, the city is infamous (声名狼藉的)for having the world’s worst traffic. Yet, on the other, its cycling infrastructure is considered a good model of sustainable urban mobility, according to the Copenhagenize Index, which ranks bike-friendly cities. The Colombian capital generated a now-international movement in the 1970s called Ciclovia, which sees 1.5 million people cycle across 128km of car-free streets each Sunday morning.

So, when the pandemic reached its shores in mid-March, Bogota Mayor Claudia Lopez, an avid cyclist herself, introduced one of the world’s first plans to encourage bike travel, using traffic cones to create 76 km of temporary lanes.

“Everyone started using a bicycle, and they already knew how to get around on one because we have this bike culture thanks to the Ciclovia,” says Carlos Pardo, a local cycling advocate and senior advisor at the New Urban Mobility Alliance. Pardo got involved at the beginning of the pandemic by partnering with a local bikeshare company to provide 400 free e-bikes to health workers. Now, he’s busy persuading the public that the government’s new bike lanes should become permanent fixture (固定设施).

“Some drivers say, ‘you took away our lane’, but we’re saying, we took one car lane and made a two-lane bidirectional bike lane,” he explains. “So, you’re duplicating the effectiveness of the space, and moving more people per hour, per direction.”

Biking has enjoyed a renaissance (复兴) around the world as urban citizens avoid public transport for the relative safety of a two-wheeled commute. Now, many advocates like Pardo are working with local governments in the hope of turning these pandemic-response measures into lasting changes—ones that are more plausible now than ever after lockdowns provided an unprecedented (空前的)opportunities to fast-track infrastructure trials. The results of these urban planning experiments could not only radically shape the way we commute across global cities, but also make them more adaptable to future shocks.