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In recent years, the best-performing artificial-intelligence systems — in areas such as autonomous driving, speech recognition, computer vision, and automatic translation — have come courtesy of software systems known as neural networks.

But neural networks take up a lot of memory and consume a lot of power, so they usually run on servers in the cloud, which receive data from desktop or mobile devices and then send back their analyses.

Robotics researchers have found a way for autonomous underwater vehicles to navigate strong currents with greater energy efficiency, which means the AUVs can gather data longer and better.

AUVs such as underwater gliders are valuable research tools limited primarily by their energy budget – every bit of battery power wasted via inefficient trajectories cuts into the time they can spend working.

Nitrogen is abundantly available in nature and forms the basis for many valuable products, both natural and artificial. This requires a reaction known as “nitrogen fixation”, whereby molecular nitrogen is split into two atoms of nitrogen that can then be connected to other elements like carbon or hydrogen. But performing nitrogen fixation to make ammonia on an industrial scale requires harsh conditions with very high temperature and pressure. EPFL scientists have now developed a uranium-based compound that allows nitrogen fixation to take place in ambient conditions. The work, published in Nature, forms a basis for the development of more efficient catalysts, while it highlights new concepts that can be expanded to metals beyond uranium.

A beam of sunlight streams into your living room, illuminating a Milky Way of dust particles hanging in the air. Although the air looks thick, those visible dust particles are so big that they can’t reach the smallest branches of the respiratory tree in your lungs. It’s the dust we can’t see—smaller than 2.5 microns, called PM 2.5—that can cause allergies and other respiratory problems.

In some places, water is dangerously scarce. In the African Sahel, generations of severe droughts have claimed millions of lives and have turned fertile pastures into swaths of desert. In Brazil, residents of the water-starved city of São Paulo have been frenetically digging homemade wells to mine fresh water, while schoolkids skip brushing their teeth as a conservation measure. And in California, devastating drought conditions in recent years idled nearly a half-million acres of crops and triggered the loss of tens of thousands of jobs.