【推荐2】Some penguins (企鹅) adapt their calls to become more similar to their partners over time, an ability that was previously known in only a few species, including humans.

Luigi Baciadonna at the University of Turin, Italy, and his coworkers recorded African penguins from three different colonies (群体) over three years, and also observed the behavioral patterns of one of the colonies to see which penguins were partners or friendly.

They then analyzed specific vocal (声音的) calls, which the penguins made when they were alone or trying to keep track of their friends. They compared four distinct vocal signatures such as the frequency of the calls. The signatures became more similar over time for penguins that were partners or in the same colony, and for penguins that heard more of each other’s calls.

This adaptation could make it easier for penguins to find their partners and friends in a colony. “Imagine that you are in a pub, you are with your friends and your environment is quite noisy,” says Baciadonna. “What you do is try to talk in a certain way so that your communication is more effective.”

The ability to adapt calls in response to the environment, known as vocal accommodation, is a key part of vocal learning, a more complex set of skills such as producing new sounds through learning. Identifying which species display vocal accommodation could provide clues for how vocal learning developed. Baciadonna and his team also propose that this accommodation could help with group harmony and social bonds between individual penguins.

The distance of penguins from humans on the evolutionary tree suggests that vocal accommodation could be common to many species, but a lot more data needs gathering first. “There could be a huge variety of different species that are able to adapt their calls slightly, but we don’t know that yet,” says Sara Torres Ortiz at the Max Planck Institute for Ornithology in Munich, Germany.

【推荐3】For the first time, researchers have used an animal’s own chemistry to grow electrodes (电极) inside the tissues of living fish, making the boundary between biology and machines difficult to distinguish.

The technique uses the body’s sugars to turn an injected gel into a flexible electrode without damaging tissues, experiments show. Zebrafish with these electrodes grown in their brains, hearts and tail fins showed no signs of ill effects, and electrodes tested in leeches (水蛭) successfully stimulated a nerve, researchers report in the Feb. 24 Science.

Someday, these electrodes could be useful for studying how biological systems work or improving human-machine interfaces. They also could be used in brain stimulation therapies for depression, Parkinson’s disease and other conditions.

Soft electronics aim to bridge the gap between soft, curvy biology and electronic hardware. But these electronics typically still must carry certain parts that can be easy to cracks and other issues that impact performance. And inserting these devices inevitably damages tissues, says Magnus Berggren, a materials scientist at Linköping University in Sweden.

Growing soft electronics inside tissues can have weaknesses too. External electrical or chemical signals that transform chemical soup into electrodes can cause damage. It’s possible to genetically modify cells to make enzymes that do the job. But Berggren and colleagues’ method gets results without genetic alterations.

The fish appeared to suffer no ill effects, and the team saw no evidence of tissue damage. In leeches, delivering a current to a nerve via a soft electrode induced muscle contractions.

“The approach utilizes elegant chemis try to overcome many of the technical challenges,” says biomedical engineer Christopher Bettinger of Carnegie Mellon University in Pittsburgh. But long-term performance is unclear. Substances in the body could reduce electrodes. “The team also needs to improve how precisely the electrodes stimulate nerves,” says chemical engineer Zhenan Bao of Stanford University. “The relative abundance of sugars in tissues dictates where electrodes form for now,” Berggren says. “Swapping a component in the material for elements that attach to specific bits of biology could make targeting more precise,” he says.

【推荐1】Brown cows may not actually make chocolate milk, but pink silkworms（蚕）do produce pink silk, a team of scientists has discovered. To see if they could produce pre-dyed silk-silk that comes colored, straight from the source-the team fed ordinary silkworms mulberry（桑树）leaves that had been sprayed（喷洒）with fabric（织物）dyes（染色剂）. Out of seven tested dyes, only one worked, producing a thread that reminded me of pink-dyed hair.

And yes, the worms themselves take on some color before they produce silk. Their colorful diets did not affect their growth, the team, which included engineers and biologists from the CSIR-National Chemical Laboratory in India, reports in the journal ACS Sustainable Chemistry & Engineering. (The researchers didn't look too deeply into how the dyes affected the silkworms' health. After all, silkworms die when people harvest their silk.)

The team made dyeing silk this way because coloring fabric normally uses large amounts of fresh water. The water gets polluted with dangerous chemicals in the process, requiring costly treatment before factories can send it back into waterways. Dyeing silk directly by feeding silkworms would avoid those water-washing steps. Scientists are just starting to study this idea. However, it remains to be seen if it's commercially successful. In this experiment, the Indian team tested seven dyes, which are cheap and popular in the industry.

The scientists found different dyes moved through silkworms' bodies differently. Some never made it into the worms' silk at all. Others colored the worms and their silk, but the color disappears before the silk is turned into fabric. Only one dye, named "direct acid fast red", showed up in the final, washed silk threads. By the time it made it there, it was a pleasant, light pink.

【推荐2】In Kenya, two university students from rural villages came up with a system to recharge a cellphone battery using energy generated from a bicycle. They took most of the items from a junkyard. Innovation and leadership strategist Navi Radjou thinks that such frugal(节俭的) innovation enables socially and environmentally responsible economic development through products and services that combine four qualities: affordability, accessibility, sustainability, and quality. He advises that we should use what is rich to handle what is scarce.

It’s an approach that is having a huge impact. Among things becoming rich in developing countries are connectivity and smartphones. A great example of frugal innovation is Peek Retina, a small adapter(适配器) for a smartphone that lets people perform eye exams without any of the fancy equipment you stare into at your optometrist’s. Another great frugal innovation is Foldscope, a microscope that costs 50 cents to make but can do serious diagnoses(诊断). With the wide use of the microscope, people can be easily tested instead of traveling long distances to see a doctor and a real hands-on science education can be provided for all remote health workers.

Frugal Innovation is a new trendy term for something that has been around for a while; in the 1980s it was MacGyver; in the 1970s it was Adhocism. Basically it involves using an available system or dealing with an existing situation in a new way to solve a problem quickly and effectively. It is a method of creation relying particularly on resources which are already at hand. By getting back to basics, frugal innovation allows low-income populations to play a major part in their own progress.

It may be the same as it ever was under a new name, but there are new tools and new ways of sharing. The new smartphone technology and the speed of communication and spread of information really make this a new age of Frugal Innovation. And it’s not just in the developing world, it can work anywhere. So welcome to the new buzzword(流行词), Frugal Innovation.

【推荐3】Amazon has plans to drop off packages directly into shoppers’ houses. The world’s largest online retailer has announced Amazon Key, a lock and camera system that users control remotely to let delivery associates (伙伴) put goods into their houses. Customers can create temporary passwords (密码) for friends and other service professionals to enter as well.

The smart lock may help Amazon get sales from shoppers who cannot make it home to receive an order, and don’t want the package stolen from their doorstep. It also signals Amazon’s determination to win the market of home security devices, where Alphabet Inc.’s Nest Labs competes.

“This is not an experiment for us，” said Peter Larsen, Amazon vice president of delivery technology, in an interview. “This is a key part of the Amazon shopping experience from this point forward.”

Members of Amazon’s Prime shopping club can pay $249.99 and up for a cloud­controlled camera and lock that the company offers to install. Delivery associates are told to ring a doorbell or knock when they arrive at someone’s house. If no one greets them, they press “unlock” in a mobile app, and Amazon checks its systems in an instant to make sure the right associate and package are present. The camera then streams the video to the customer who remotely can watch the in­home delivery take place. The associate cannot proceed with other trips until the house is again locked.

It is unclear whether such protections will persuade customers that the service is safe to use. Larsen said stealing was “not something that happens in practice”， based on early tests of the Amazon Key program. He added that if a problem arises, “You can call customer service and Amazon will work with you to make sure it’s right, reimbursing (赔偿) you for any loss or damage in some cases.”