【推荐1】Tiny microbes(微生物) are at the heart of a new agricultural technique to manage harmful greenhouse gas. Scientists have discovered how microbes can be used to turn carbon dioxide into soil-enriching limestone(石灰石), with the help of a type of tree that grows in tropical areas, such as West Africa.

Researchers have found that when the Iroko tree is grown in dry, acidic soil and treated with a combination of natural fungi(霉菌) and other bacteria, not only does the tree grow well, it also produces the mineral limestone in the soil around its root.

The Iroko tree makes a mineral by combining Ca from the earth with CO₂ from the atmosphere. The bacteria then create the conditions under which this mineral turns into limestone. The discovery offers a new way to lock carbon into the soil, keeping it out of the atmosphere. In addition to storing carbon in the trees’ leaves and in the form of limestone, the mineral in the soil makes it more suitable for agriculture.

The discovery could lead to reforestation(重新造林) projects in tropical countries, and help reduce carbon dioxide in the atmosphere in the developing world. It has already been used in West Africa and is being tested in Bolivia, Haiti and India.

The findings were made in a three-year project involving researchers from the Universities of Edinburgh, Granada, Lausanne and Delft University of Technology. The project examined several microbiological methods of locking CO₂ as limestone, and the Iroko-bacteria way showed best results. Work was funded by the European Commission under the Future&Emerging Technologies(FET) scheme.

Dr Bryne Ngwenya of the University of Edinburgh’s School of GeoSciences, who led the research, said:“By taking advantage of this natural limestone-producing process, we have a low-tech, safe, readily employed and easily operating way to lock carbon out of the atmosphere, while improving farming conditions in tropical countries.”

【推荐3】If you live in Washington, D. C., or Redwood, Calif., you may have glimpsed a small, boxy robot rolling along a local sidewalk, minding it’s own business, but attracting the attention of many a curious onlooker. The autonomous machines were part of a pilot program last year by Starship Technologies focused on delivering meals from local restaurants in dozens of cities around the world.

“Today, more than ever, people lead a busy and diverse life,” Lex Bayer, Starship’s CEO, said in a statement online. “The hassle of needing to rearrange your life for a delivery will become a thing of the past. You don’t have to switch your working from home day, reschedule meetings, visit a locker, drive to a post office or contact a deliveryman all because of a missed delivery.”

The package delivery service is not available to everyone just yet. The company said it’s rolling out the service in Milton Keynes, England. The wheeled robots have a top speed of 4 mph and can detect obstacles from as far as 30 feet away. “The robot can operate through just about anything,” Nick Handrick, head of operations for Starship’s D. C. office, told The Washington Post's Maura Judkis last year. “If you had something in the way—a stick—it’s able to climb the edges of a road.”

By giving customers control of when deliveries occur, Starship Technologies is offering its service as a way to battle package theft. In its announcement, the company cited statistics from a Wakefield Research Poll for Comcast last year that found that 3 in 10 Americans who live in houses or townhouses have had packages stolen.

To sign up for the service, which costs a little more than $10 per month, customers need to download the company's app. Customers then create a “Starship Delivery Address,” a unique address inside a Starship facility, instead of a residence, where they can have packages sent from places such as Amazon, com. Once a package is delivered to the Starship address, customers receive a text that allows them to schedule a home delivery via robot.

【推荐1】What defines who we are? Our habits? Our tastes? Our memories? I would say it must be my deep-seated sense of right and wrong.

And yet, like many other people who speak more than one language, I often have the sense that I’m a slightly different person in each of my languages — more confident in English, more relaxed in French. Is it possible that my moral compass also points in somewhat different directions depending on the language I’m using?

Several recent psychological studies suggest that when people are faced with moral dilemmas, they do respond differently when considering them in their native and foreign tongue.

In a 2014 paper led by Albert Costa, volunteers were presented with a moral dilemma known as the “trolley problem”: imagine that a runaway trolley is dashing toward a group of five people standing on the tracks, unable to move. You are next to a switch that can shift the trolley to a different set of tracks, thereby sparing the five people, but resulting in the death of one who is standing on the side tracks. Do you pull the switch?

Most people agree that they would. But what if the only way to stop the trolley is by pushing a large stranger off a footbridge into its path? People tend to be very reluctant (不情愿的) to say they would do this. But Costa and his colleagues found that posing the dilemma in a language that volunteers had learned as a foreign tongue dramatically increased their willingness, from fewer than 20% of respondents working in their native language to about 50% of those using the foreign one.

Why does it matter whether we judge morality in our native language or a foreign one? According to one explanation, such judgments involve two separate and competing modes of thinking — one of these, a quick, gut-level “feeling,” and the other, careful deliberation about the greatest good for the greatest number. When we use a foreign language, we unconsciously sink into the more deliberate mode simply because the effort of operating in our non-native language cues our cognitive (认知) system to prepare for strenuous (费力的) activity. An alternative explanation is because our childhood languages change with greater emotional intensity than do those learned in more academic settings. As a result, moral judgments made in a foreign language are less burdened with the emotional reactions.

What then is a multilingual (多语言的) person’s true “moral self”? Is it my moral memories? Or is it the reasoning I’m able to apply when free of such unconscious restrictions? Or perhaps, as the research implies, regardless of how many languages we speak: that our moral compass is a combination of the earliest forces that have shaped us and the ways in which we escape them.

【推荐2】Art has always been a polarizing(分化的)subject.Some people like realism,others like abstract.But do you know why some people value art in the millions,while others see the same piece as little more than a child’s finger painting?

Many consider art to be quite random in terms of our likes and dislikes.But according to new research,there may actually be a scientific reason behind our fondness for certain works.The answer lies in how a person’s brain breaks down the visuals(视觉效果)of a painting combined with their judgment.

To prove their theory,neuroscientist(神经科学家)Kiyohito Iigaya and his team from the California Institute of Technology(Caltech)gathered more than 1,300 volunteers and asked them to rate 825 different paintings from four different art genres(类型).

After analyzing the data,scientists found that the same groups of people tended to prefer similar aspects of the same paintings.These characteristics were then grouped into“low-level”features like color and blending,and“high-level”features like the emotion behind the painting.

From this experiment,Caltech’s system was then able to predict an individual’s specific taste in art and organize different works into one group,according to the paintings’features and volunteers’preferences.

In a second test,researchers repeated the experiment on six volunteers,showing each 1,000 paintings while inside an MRI—a machine that scans a person’s brain activity.The test revealed(揭示)that the different features of a painting are sent to the part of the brain that deals with valuing items,allowing someone to form their overall opinion.

Finally,the team repeated the first test on new volunteers.Again,the algorithm(算法)was able to accurately predict individuals’art preferences.According to Iigaya,this shows that the factors that contribute to whether a person likes an image are universal,not random.

Lesley Fellows,a neurologist at McGill University who studies value judgments,stated,“We know a lot about‘how’the brain carries out actions,but‘why’is far less well understood.”

【推荐3】AI that Sees like Humans

For most of the past 30 years computer-vision technologies have struggled to perform well, even in tasks as boring as accurately recognizing faces in photographs.     1    . Companies are already selling products that exploit the technology, which is likely to take over or assist in a wide range of jobs that people now perform.

CNNS do not need to be programmed to recognized specific features in images--- for example, the shape and size of an animal’s ears.     3     To train a CNN to separate an English springer spaniel (斯柏林格斯班尼犬) from a Welsh one, for instance , you start with thousands of images of animals, including examples of both breeds. Like most deep-learning networks, CNNS are organized in layers. In the lower layers, they learn simple shapes and edges from the images. In the higher layers, they learn complex and abstract concepts--- in this case, the more detailed aspects of ears, tails, tongues, fur textures, and so on.

CNNS were made possible by the tremendous progress in graphic processing units and parallel processing in the past decade. But the Internet has made a big difference as well by feeding CNNs’ appetite for digitized images.     4     The technology is making self-driving cars safer by enhancing the ability to recognize pedestrians. Insurers are starting to apply these tools to assess damage to cars. In the security camera industry, CNNS are making it possible to understanding crowd behavior, which will make public places and airport safer.

【推荐1】In a recent series of experiments at the University of California, researchers studied toddlers’ thinking about winners and losers, bullies (欺凌) and victims.

In the first experiment, toddlers (学步儿童) watched a scene in which two puppets (木偶) had conflicting goals: One was crossing a stage from right to left, and the other from left to right. The puppets met in the middle and stopped. Eventually one puppet bowed down and moved aside, letting the other one pass by. Then researchers asked the toddlers which puppet they liked. The result: 20 out of 23 toddlers picked the higher-status puppet — the one that did not bow or move aside. It seems that individuals can gain status for being dominant (占优势的) and toddlers like winners better than losers.

But then researchers had another question: Do toddlers like winners no matter how they win? So, researchers did another experiment very similar to the one described above. But this time, the conflict ended because one puppet knocked the other down and out of the way. Now when the toddlers were asked who they liked, the results were different: Only 4 out of 23 children liked the winner.

These data suggest that children already love a winner by the age of 21-31 months. This does not necessarily mean that the preference is inborn: 21 months is enough time to learn a lot of things. But if a preference for winners is something we learn, we appear to learn it quite early.

Even more interesting, the preference for winners is not absolute. Children in our study did not like a winner who knocked a competitor down. This suggests that already by the age of 21-31 months, children’s liking for winners is balanced with other social concerns, including perhaps a general preference for nice or helpful people over aggressive ones.

In a time when the news is full of stories of public figures who celebrate winning at all costs, these results give us much confidence. Humans understand dominance, but we also expect strong individuals to guide, protect and help others. This feels like good news.

【推荐2】Oxygen, I'm sure you'd agree, is pretty important for life on Earth. We breathe it in, our cells survive on it and without it, we hardly live. Basically all multicellular life on Earth evolved over millions of years to make use of oxygen.

But take a deep breath, because we need to talk about Henneguya salminicola, a tiny parasite(寄生虫) containing fewer than100 cells that lives within the muscle tissue of salmon, a large fish with silver skin and pink flesh. The strange-looking parasite does not busy itself with such small matters as breathing oxygen. Nope, it seems that H. salminicola is the first multicellular animal we've found that survives without the stuff.

“Aerobic respiration(有氧呼吸) was thought to be commonly found in animals, but now we confirmed that this is not the case, "said Dorothee Huchon, a zoologist at Tel Aviv University in Israel, in a press release.

Huchon and a team of international researchers examined and sequenced(排序) all of. salminicola's' genes in their study, published in the journal Proceedings of the National Academy of Sciences. They found that the parasite, which is closely related to jellyfish, lacks the DNA machinery necessary to“breathe”---it doesn't' have mitochondria(线粒体), often called the "powerhouse" of the cell, because they use oxygen to make energy. It's like a little factory inside almost all cells, and DNA detectives can find mitochondrial genes during sequencing.

The discovery came as something of an accident for the team, who were examining the genome (the complete set of genes) of the species. When they went searching for the mitochondrial genes,   they came up empty-handed. "Our discovery shows that evolution can go in strange directions, ”Huchon said. "Aerobic respiration is a major source of energy, and yet we found an animal that gave up this important pathway.”

Some single-celled life forms have evolved the ability to survive without oxygen and do not have mitochondria, either. Plenty of bacteria can exist without oxygen at all. Instead of oxygen, they get their energy from fermentation(发酵) or use other molecules like iron.

But how H. salminicola produces energy is still unclear. Huchon suggests it could draw oxygen from the cells in salmon or it could have evolved similar methods to those of single-celled organisms which scientists have documented in the past.

【推荐3】Babies are surrounded by human language, always listening and processing. Eventually, they put sounds together to produce a “Daddy” or a “Mama”. But what still confuses neuroscientists is exactly how the brain works to put it all together.

To figure it out, a team of researchers turned to a frequent stand-in (代替) for babies when it comes to language learning: the song-learning zebra finch. “We’ve known songbirds learn their song by first forming a memory of their father’s song or another adult’s song. Then they use that memory to guide their song learning,” said Neuroscientist Todd Roberts. “It’s been a long-term goal of the field to figure out how or where in the brain this memory is. This type of imitative learning that birds do is very similar to the type of learning that we engage in regularly—particularly when we’re young, we use it to guide our speech learning.”

Roberts and his team had a feeling that the interface (交叉区域) between sensory areas and motor areas in the brain was critical for this process, and they focused on a group of brain cells called the NIf.

“In order to prove that we could identify these circuits, we thought if we could implant a false memory.” First, they used a virus to cause the neurons (神经元) in the birds’ NIf to become sensitive to light. Then, using a tiny electrode as a flashlight, they activated (激活) the neurons. The length of each pulse of light corresponded with the amount of time the neurons would fire. And the birds’ brains interpreted that time period as the length of each note.

Soon enough, the birds began to practice the notes they had learned, even though they never really heard the sounds. Amazingly, the birds produced them in the correct social situations. The researchers say this is the first time anybody has found exactly a part of the brain necessary for generating the sorts of memories needed to copy sounds.

“This line of research is going to help us identify where in the brain we encode memories of relevant social experiences that we use to guide learning. We know that there are several neurodevelopmental disorders in people that have really far-reaching effects on this type of learning.”

【推荐2】According to a new study from Cornell University, about one-fifth of the global population, of 2 billion people worldwide, will be forced to resettle or go deeper inland by 2100 due to the continuous rise in sea level.

The study, published in the journal Land Use Policy, showed that the growing global population could make the matter worse. The researchers expected that there are about 1.4 billon “climate change refugees(难民)” in the world by 2060 and by 2100 the number of the displaced people due to the rising sea level could reach up to two billion.

“We’re going to have more people on less land and sooner than we think,” said lead author Charles Geisler, professor at Cornell. “The future rise in global average sea level probably won’t be gradual. Yet few policy makers are observing the significant barriers that coastal climate refugees, like other refugees, will run into when they move to higher ground.”

For the study, the researchers reviewed(回顾) potential problems that climate change refugees may face if they go deeper inland. The researchers identified these land difficulties with relocation using three organizing groups. Including depletion(损耗) zones, win-lose zones and no-trespass(不得擅自进入) zones. By doing so, the researchers were able to provide primary estimates of their toll(损失) on inland resettlement space. The researchers found that some inland regions were unlikely to support new waves of climate change refugees due to the remains of war, road developments and rare natural resources.

Apart from the rising sea level, increasing storm weather and the booming global population are also having a huge influence on the number of climate change refugees. Storm can push seawater further inland. The increasing global population requires more land even as the ocean swallows up rich costal zones and river deltas(三角洲). These force people to search for new places to move to higher ground.

【推荐3】Deo had grown up barefoot in Burundi, but for a peasant boy he had done well. He was twenty-four. Until recently he had been a medical student, for three years at or near the top of his class. But he had spent the past six months on the run.

He had one friend who had seen more of the world than East Central Africa, a fellow medical student named Jean. And it was Jean who had decided that New York was where he should go. Deo was traveling on a commercial visa. Jean’s French father had written a letter identifying Deo as an employee on a mission to America. He was supposed to be going to New York to sell coffee. Deo had read up on coffee beans in case he was questioned. Jean’s father had also paid for the plane tickets. A fat book let of tickets.

He had heard of French soldiers behaving badly in Rwanda, and had even caught glimpses of them training militiamen(民兵) in the camps, but waking up and seeing a white person in the next seat wasn’t alarming. No one called him a cockroach (蟑螂). No one held a machete (大砍刀).

A voice was speaking to him. He turned and saw a policeman who seemed friendly. Deo spoke to him in French, but the man shook his head and smiled. He asked a question in what Deo guessed was English. Then a woman who had been sitting nearby got up and walked over French, at long last French, coming out of her mouth. Perhaps she could help, the woman said in French. Deo thought: “God. I’m still in your hands.” She arranged to sit next to him on the flight to New York and asked him lots of questions. Deo wanted to pay her back for helping him. So he tried to answer her questions. They talked most of the way to New York. After such long solitude (独处), it felt wonderful to talk.

When he reached Immigration the agent stared at Deo’s documents, then started asking questions in what had to be English. There was nothing to do except smile. The agent went off and came back with another man. He introduced himself to Deo in French. His name was Muhammad. He said he came from Senegal. Muhammad asked Deo the agents’ questions and also some questions of his own. For the agents, he asked Deo, “Where are you coming from?” When Deo said he had come from Burundi, Muhammad made a pained face and said to him in French, “How did you get out?”

There was no time even to attempt an answer. The agents were asking another question: Deo’s visa said he was here on business. What business?

Selling coffee beans, Deo told them through Muhammad. Just keep smiling, Deo told himself.

How much money did he have?

Two hundred dollars, Deo said with pride. The cash had been a gift from Jean. Exchanged for Burundian francs, it could have bought a lot of cows. But neither Muhammad nor the agents looked impressed.

Where was he staying?

Jean had told him he’d be asked this. A hotel, he said.

The agents laughed. A week in a hotel on two hundred dollars?

In 1994, airport security wasn’t what it soon would be. Muhammad said something in English to the agents. His words must have been the right ones, because after a few more questions, the agents shrugged at each other and let him through, into America.

He had no idea what he’d do next. After six months on the run, he was in the habit of not looking ahead. And what was there to fear? What could the man in the booth up ahead do to him? Whatever it might be, he’d already seen worse. God had taken care of him so far. And still was taking care of him, it seemed. As this serious-looking stranger, Muhammad, walked him out of Customs, he said that Deo could stay with him in New York City. But Deo would have to wait here for three hours. Muhammad worked at the airport as a baggage handler. He had to finish his shift. Could Deo wait three hours?

Only three hours? said Deo. Of course!