【推荐1】Like most of us, I try to be mindful of food that goes to waste. The arugula (芝麻菜)was to make a nice green salad, rounding out a roast chicken dinner. But I ended up working late. Then friends called with a dinner invitation. I stuck the chicken in the freezer. But as days passed, the arugula went bad. Even worse, I had unthinkingly bought way too much; I could have made six salads with what I threw out.

In a world where nearly 800 million people a year go hungry, “food waste goes against the moral grain,” as Elizabeth Royte writes in this month’s cover story. It’s jaw-dropping how much perfectly good food is thrown away — from “ugly” (but quite eatable) vegetables rejected by grocers to large amounts of uneaten dishes thrown into restaurant garbage cans.

Producing food that no one eats wastes the water, fuel, and other resources used to grow it. That makes food waste an environmental problem. In fact, Royte writes, “if food waste were a country, it would be the third largest producer of greenhouse gases in the world.”

【推荐2】Although many companies offer tuition reimbursement (偿付), most companies reimburse employees only for classes that are relevant to their positions.     1     A company that reimburses employees for all college credit courses — whether job related or not — offers a service not only to the employees, but to the entire company.

One good reason for giving employees unconditional tuition reimbursement is that it shows the company’s dedication to its employees and it is important for a company to demonstrate to its employees that it cares. The best way to do this is to make investments in them.

    2     A company that puts out funds to pay for the education of its employees who go on to another job in a different company as soon as they get their degree, more often than not, the employees will stay with the company.     3     Thus, throughout those ears, the employer will have a more sophisticated, more intelligent, and therefore more valuable and productive employee. And, if the employee stays, that education will doubly benefit the company: Not only is the employee more educated, but now that employee can be promoted so the company doesn’t have to fill a high-level vacancy from the outside. Open positions can be assigned to people who already know the company well.

Though unconditional tuition reimbursement requires a significant investment on the employer’s part, it is perhaps one of the wisest investments a company can make.

【推荐3】Many people would answer the question of what makes us human by insisting that we are cultural beings. There is no doubt that we are. But one definition of culture is the totality of traditions acquired in a community by social learning from other individuals, and many animal species have traditions. Can we then say that some animals are cultural beings too?

One approach to study culture in animals is the so-called Method of Exclusion (排除), in which scientists investigate behavioral variations across populations of one species. In a famous study, scientists learned that chimpanzee (黑猩猩) behaviors were socially passed on as they were present at some sites but not at others, despite having same ecological settings. For example, chimpanzees in Tai National Park in Ivory Coast are well-known for their nut-cracking skills. Chimpanzees in Gombe national part in Tanzania, on the other hand, do not crack nuts, although nuts exist in their environment too.

However, when applying the Method of Exclusion, one has to be very careful. There are other factors that could also explain the pattern of behavioral evaluation. For example, some of the chimpanzee techniques scientists evaluated occur in only one of the three subspecies. So it’s quite possible that these behaviors also have an innate component. This would mean that one chimpanzee subspecies uses a new technique not out of cultural tradition, but because the behavior is fixed to specific genes. Another factor that has to be excluded is of course the environment Chimpanzees in Mahale do not fish algae (水藻), simply because algae does not exist there.

But when we exclude all the variations that can be explained by genes or environment, we still find that animals do show cultural variations. Does that mean there is no real difference between them and us after all? Not exactly: There is a fundamental difference between human and animal culture. Only humans can build culturally on what generations before us have learned. This is called “cumulative culture”. We don’t have to keep reinventing the wheel. This is called the “ratchet (棘轮) effect”. Like a ratchet that can be turned forward but not back, people’s cultural techniques evolve.

It is likely that behaviors we see today in chimpanzee cultures could be invented over and over again by individual animals themselves. In contrast, a child born today would not be able to invent a computer without the knowledge of many past generations.

【推荐1】People trained to detect lies often rely on multiple signs, such as eye contact, length of responses and the details in what people say, but studies have shown that assessing a wide range of behavioural information can make it harder to decide if someone is lying. Bruno Verschuere at the University of Amsterdam and his colleagues wondered whether solely focusing on the detail of statements could provide more consistent results.

To test this idea, researchers asked 44 students to go for a walk or steal from a mock (模仿的) crime. Students were instructed to lie if they committed the fake theft.

Next, the researchers recruited 171 people to watch six truthful and six deceptive (欺骗的) interviews from these recordings, ranking interviewees’ eye contact and detail level. The results revealed that both truth-tellers and liars averted (转移) their gaze a similar amount, but truthful statements were substantially more detailed than deceptive ones, suggesting the latter is a more useful way to tell that someone is lying.

......

【推荐3】Humans have long gained pleasure from the smells of the natural world. For the most part, though, human beings are not their target market. For plants, fragrances are a way to interact with insects and other animals. Their attraction for people happens simply by chance.

In chemical terms, most natural fragrances are made up of volatiles—so called because of their tendency to change states suddenly. Volatiles evaporate easily, drifting into noses. In plants’ reproductive processes, smelly volatiles attract pollinators (授粉昆虫). But their natural applications are much more varied. If an insect chews through the leaves of some Bursera plants, out shoots a sticky, smelly liquid to trap it. Coyote tobacco plants are even more crafty: upon sensing the smell of hungry caterpillars, they produce volatiles that attract predators to kill the pests.

What is truly amazing is just how wily plants can be in using their scents for reproduction. White flowers often emit their scent at night to attract nocturnal pollinators such as moths. They produce a dilute nectar (稀释的花蜜) that encourages moths to keep moving, rather than linger at a single bloom—all the better to increase pollination. Other flowers change their fragrance after being successfully pollinated, as a signal for insects to go elsewhere.

But though “Scent” is a story of plants’ cleverness, it is also a tale of the human kind. People have long used fragrances for their own purposes, particularly for use in religious ceremonies: perfume recipes on the walls of an Egyptian temple in Edfu demonstrate just how long ingredients have been mixed in pursuit of the best blend. So highly prized were some scents that, to scare off competitors, Arab traders spread a legend about giant eagles that guarded cinnamon.

Eventually scientists no longer needed natural sources for fragrances. In 1866 a fragrance molecule was produced for the first time. Sixteen years later, Houbigant Parfum released Fougère Royale, the first “modern fantasy perfume” that creates an imaginary scent rather than copying a natural one. Nowadays fragrance–making is dominated by man–made compounds, which can be reliably and affordably produced in large quantities.

That has led to the mass production of smelly products, from toilet paper to toothpaste. Scent is accordingly big business. It is said that a world–famous fragrance and flavour manufacturer that claims people interact with its products up to 30 times a day, had sales of €3.8bn last year.

【推荐2】My name is Alice. Early last year, I was troubled by an anxiety that crippled ( 削弱 ) my ability to do anything. I felt like a storm cloud hung over me. For almost a year I struggled on, constantly staring at this wall that faced me. My perfectionist tendencies were the main root of this: I wanted to be perfect at whatever I did, which obviously in life is not possible, but it consumed me.

One day, I attended a presentation by wildlife conservationist Grant Brown at my high school. His presentation not only awed and inspired me, but also helped emerge an inner desire to make a difference in the world. I joined a pre-presentation dinner with him and that smaller setting allowed me to slowly build up my courage to speak one-on-one with him—an idea that had seemed completely impossible. This first contact was where my story began.

A month later, Brown invited me to attend the World Youth Wildlife Conference. Looking back, I now see that this would be the first in a series of timely opportunities that my old self would have let pass, but that this new and more confident Alice enthusiastically seized. Shortly after I received his invitation, applications to join the Youth for Nature and the Youth for Planet groups were sent around through my high school. I decided to commit to completing the applications, and soon I was a part of a growing global team of young people working to protect nature. Each of these new steps continued to grow my confidence.

I am writing this just six months since my journey began and I’ve realised that my biggest obstacle ( 障碍 ) this whole time was myself. It was that voice in the back of my head telling me that one phrase that has stopped so many people from reaching their potential: I can’t. They say good things come to those who wait; I say: grab every opportunity with everything you have and be impatient. After all, nature does not require our patience, but our action.

【推荐3】Can a small group of drones (无人机) guarantee the safety and reliability of railways and, at the same time, help railway operators save billions of euros each year? That is the very likely future of applying today’s “eyes in the sky” technology to making sure that the millions of kilometres of rail tracks and infrastructure (基础设施) worldwide are safe for trains on a 24/7 basis.

Drones are already being used to examine high-tension electrical lines. They could do precisely the same thing to inspect railway lines and other vital aspects of rail infrastructure such as the correct position of railway tracks and switching points. The more regularly they can be inspected, the more railway safety, reliability and on-time performance will be improved. Costs would be cut and operations would be more efficient (高效) across the board.

That includes huge savings in maintenance costs and better protection of railway personnel safety. It is calculated that European railways alone spend approximately 20 billion euros a year on maintenance, including sending maintenance staff, often at night, to inspect and repair the rail infrastructure. That can be dangerous work that could be avoided with drones assisting the crews’ efforts.

By using the latest technologies, drones could also start providing higher-value services for railways, detecting faults in the rail or switches, before they can cause any safety problems. To perform these tasks, drones for rail don’t need to be flying overhead. Engineers are now working on a new concept: the rail drones of the future. They will be moving on the track ahead of the train, and programmed to run autonomously. Very small drones with advanced sensors and AI and travelling ahead of the train could guide it like a co-pilot. With their ability to see ahead, they could signal any problem, so that fast-moving trains would be able to react in time.