【推荐1】In the past months, humans have become quite familiar with the term “social distancing”. But it turns out that we are not the only ones to avoid contacting our peers when our health may be at risk: Research suggests honeybees do it, too. “It’s exciting to see that other animals are doing something analogous”, said Dr. Alessandro Cini, co-author of the research at University College London.

Scientists have found that when a hive( 蜂箱)of honeybees is under threat from the mite (螨虫)called Varroa destructor, which can cause the collapse of honeybee colonies, the bees will respond by changing the way they interact with one another.

By examining videos recorded inside the hives, the researchers found that when hives had mites, foraging(觅食的)bees performed important dances to indicate the direction of food sources and kept themselves away from the centre of the colony where young bees and the queen stayed. This may help to keep the infection at a level that can be controlled, limiting the amount of damage. “Foragers are one of the main entrance routes for the mites,“ said Cini.

The team then carried out experiments in the laboratory, artificially infecting small groups of about 12 young bees with the mites and comparing them to uninfected groups. This time the team found no increase in social distancing among infected groups-which, says Cini, may reflect that it is more important for foragers and young bees to keep their distance when the mites are present and that bees rely on one another.

“Probably social distancing is too costly on a small scale,” he said. But there were differences in grooming(梳理)behaviour: Infected bees were groomed more, inspected more, and had food shared with them more than individuals in uninfected groups.

Cini said the study showed the power of natural selection in the evolution of social behavior and also dynamic change in the social behaviour to adapt to an ever-changing environment.

【推荐2】The “butterfly effect” may have it all wrong. Instead of a single insect’s wing flap setting off a distant tornado weeks later, rain in sub-Saharan Africa can lead to more wing-flapping butterflies in southern Europe the next spring, a new study finds.

Orange with black and white wing tips, the painted lady is one of the planet’s most widespread butterflies, living on every continent except Antarctica and South America. Populations reach tens of millions in Europe alone. Like the monarch butterfly, the painted lady undertakes impressive annual migrations; its round-trip journeys of some 12,000 to 14,000 kilometers reach from sub-Saharan Africa to Scandinavia and back again. It is one of the longest known annual insect migrations. “But this migration is strange, with the number of immigrant insects arriving in Europe sometimes varying greatly year over year, which has confused naturalists for generations,” says ecologist Richard Fox.

Adult painted ladies only live about 2 weeks, so the butterflies’ migrations are multi-generational affairs. Experts have long suspected variations in spring numbers in the Mediterranean occur because conditions farther south have affected the breeding success of an earlier generation. To see whether that’s true, Jason Chapman and his colleagues collected 21 years’ worth of butterfly observations from West Africa to Western Europe. The researchers found that the butterflies’ spring numbers in Europe are heavily influenced by the amount of monsoon (雨季) rainfall in western sub-Saharan Africa in the previous summer and fall.

More rain there, they found, leads to flooding, which fuels plants that emerging larvae(幼虫) feast on in the winter. Wet years appear to have produced European butterfly booms in 2009, 2015, and this year. Spring plants amount in northwestern Africa can also affect the numbers of the painted ladies; the butterflies make some stops in the region on the way to Europe.

The findings help scientists know what a changing climate could mean to the insects, according to ecologist Constanti Stefanescu. “Now that researchers have taken some mystery out of the insects’ northward migration, one remaining puzzle is how they manage to survive their return journey southward at the end of the summer,” says another ecologist, Chris Thomas.

【推荐3】Almost every morning for the past two decades, Juliet the macaw (金刚鹦鹉) has been visiting the local zoo in Rio de Janeiro to interact with others of her kind through the metal enclosure.

Macaws are social birds, so being lonely is a tough burden to bear for Juliet, a beautiful blue-and-yellow macaw who calls Rio home. No one really knows much about her. Zoo staff named the bird Juliet, but they don't even know if she is actually female. It's really hard to tell with macaws, and to determine her true gender (性别) they would need to capture the bird, and either examine her gonads (生殖腺) or take blood or feather samples. And there's really no need to put Juliet through all that stress just to satisfy human curiosity. All that everyone knows is that Juliet loves coming to the zoo every morning to be with others of her species.

Macaws have an average life expectancy of about 35 years, and Juliet has been around for at least two decades. Yet, she has never had a mate, built a nest or had chicks, and she probably never will, because there's just no one to do it with.

Luckily, there is hope for Rio's loneliest bird. Through Refauna, an initiative which reintroduces species into protected areas, scientists want to raise some 20 chicks that will, receive training on wild food sources, as well as enemies and power line avoidance, before being released into the wild.

The birds will be released into Rio de Janeiro's giant Tijuca Forest National Park, where Juliet is believed to spend her nights. Scientists hope the birds will help keep balance in the local eco-system, by breaking seeds that other birds can't, thus spreading those seeds. But they will also become welcome company for Juliet, allowing her to fly with others of her kind for the first time in 20 years. And maybe she'll even find love.

【推荐1】A new analysis by researchers at MIT has found that inactive yeast (非活性酵母) can help remove lead pollution from drinking water supplies. The study shows that this approach works well, even for part-per-billion levels of pollution. The team has calculated that waste yeast abandoned by a single brewery (啤酒厂) in Boston would be enough to treat the city’s entire water supply. The system would not only purify the water but also change what would otherwise be some waste needing to be got rid of.

Lead and other heavy metals in water are a serious global problem that continues to grow. In the U.S. alone, more than 12,000 miles of waterways are suffering the effect of wastewater rich in heavy metals. What’s worse, heavy metals don’t break down, but continuously exist and accumulate. They are either impossible or very expensive to completely remove by conventional methods. Lead is highly poisonous, even at tiny concentrations, especially affecting children as they grow.“We don’t just need to minimize the existence of lead; we need to remove it from drinking water,” says one of the researchers called Stathatou.

The solution found by the MIT team is not a new one. A process called biosorption, in which inactive biological material is used to remove heavy metals from water, has been known for a few decades. But the process has been studied and characterized only at much higher concentrations, at the levels of more than one part per million.“Our study demonstrates that the process can indeed work efficiently at the much lower concentrations of typical real-world water supplies,” another researcher named Athanasiou says.

Designing a practical system for processing the water and getting back the yeast, which could then be separated from the lead for reuse, is the next stage of the team’s research. They are also exploring ways of recovering both the yeast and the lead, “We need to conduct further experiments, but there is the option to get both back. And it will be a blessing for the world.” Stathatou says.

【推荐1】When we get dressed or play ball, our brain is constantly planning ahead so that we can move our body without bumping, tripping, or falling over. We humans acquire our body-model as infants, and now robots are following suit.

A Columbia engineering team announced they had created a robot that , for the first time, was able to learn a model of its entire body from nothing, without any human assistance.

The researchers placed a robotic arm inside a circle of five streaming video cameras. The robot watched itself through the cameras as it moved freely. Like an infant exploring itself for the first time in a hall of mirrors, the robot wiggled (扭动) to learn how exactly its body moved in response to various motor (运动神经) commands. After about three hours, the robot stopped. Its deep neural network bad finished learning the relationship between its motor actions and the volume it occupied in its environment.

The ability of robots to model themselves without being assisted by engineers is important for many reasons. Not only does it save labor, but it also allows the robot to keep up with its own wear-and-tear, and even detect and compensate for damage. A factory robot, for instance, could detect that something isn’t moving right, and compensate or call for assistance.

The research work is part of the scientists’ decades-long quest to find ways to grant robots some form of self-awareness. Self-modeling is a primitive form of self-awareness. If a robot, animal, or human has an accurate self-model, it can function better in the world, it can make better decisions, and it has an evolutionary advantage.

The researchers are aware of the limits, risks, and controversies surrounding granting machines greater autonomy through self-awareness. They say the kind of self-awareness demonstrated in this study is insignificant compared to that of humans, but they have to start somewhere, Surely, scientists have to go slowly and carefully, so we can reap the benefits while minimizing the risks.