【推荐1】San Francisco— After years of testing with a human backup(后补的) driver, General Motor’s Cruise is launching fully driverless cars onto public streets in San Francisco, the most complex urban environment robocars that have been tested, the company announced.

The company said on Wednesday it was deploying(部署) five self-driving vehicles in San Francisco’s Sunset District, an area that has many of the city’s typical traits: narrow and busy streets, steep inclines(坡度) and fog. Cruise said it was confident enough to launch the driverless trials after five years’ testing.

The company, which began the driverless testing in November, said it plans to expand to other neighborhoods. But the first tests will not put the driverless vehicle fully in control. Instead, the backup driver will be effectively moved to the passenger seat at early trials. Although those operations will not involve traditional driver controls, they will be able to stop the vehicle if there is an emergency.

Companies in Silicon Valley and elsewhere are working to make driverless vehicles a reality, saying that they will help decrease motor vehicle deaths, which number around 40, 000 annually, and allow cheaper ride-hailing(打车) trips by removing the need to pay a human driver.

Companies such as Cruise and competitor Zoox have set their sights on San Francisco, seeing the potential reward of conquering a complex urban environment and the country’s second-most populated major city, rather than starting small and gradually making progress.

【推荐2】To persist, life must reproduce. Scientists at the University of Vermont, Tufts University, and the Wyss Institute for Biologically Inspired Engineering at Harvard University have discovered an entirely new form of biological reproduction and applied their discovery to create the first-ever, self-replicating (自我复制的) living robots.

Named Xenobots after the African clawed frog from which scientists take their stem cells, the machines are less than 0.04 inches wide—small enough to travel inside human bodies. They can walk and swim, survive for weeks without food, and work together in groups. They even have regenerative capabilities; when the scientists sliced into one robot, it healed by itself and kept moving.   

The Xenobots could potentially be used toward a host of tasks. Xenobots could be used to clean up radioactive waste and collect microplastics in the oceans. Some Xenobots had holes in their center, which could potentially be used to transport drugs or medicines. “Traditional robots degrade (降解) over time and can produce harmful ecological and health side effects,” researchers said in the study, which was published in the Proceedings of the National Academy of Sciences. As biological machines, Xenobots are more environmentally friendly and safer for human health. Aside from these immediate practical tasks, Xenobots could also help researchers to learn more about cell biology—opening the doors to future advancement in human health and longevity.

While the prospect of self-replicating biotechnology could spark concern, the researchers said that the living machines were entirely contained in a lab and easily destroyed, as they are biodegradable and regulated by experts. “There are many things that are possible if we take advantage of this kind of plasticity (可塑性) and ability of cells to solve problems,” said Joshua Bongard, one of the lead researchers at the University of Vermont.