“Leaves on the line” is a troublesome term for rail operators.

When leaves fall on to a railway line, they form an extremely low-friction black paste. When compressed by a slowly moving train, the paste becomes sticky and prevents the wheel from touching the rail, leading to lengthy delays and extreme safety concerns.

Discovering why leaves pose such a problem has taken years of research.

Sycamore (梧桐树) leaves are known to create this slippery black substance. It reduces friction between wheel and rail to around 0.01 per cent — the same as between ice and a skate.

To find out what chemical in the leaves was responsible for the paste, the researchers used a process of elimination (排除过程). Different chemicals were removed but the paste still formed. However, when tannins (单宁酸) were removed, the paste did not form.

In plants, these large molecules are used to soak up disease and stop it spreading, as well as making the plants taste bitter in order to discourage animals from eating them. But when the leaves fall on to a railway line, these tannins react with charged iron particles from the steel rails to form an extremely low-friction black paste.

“With this chemical reaction found and linked to low friction phenomena, interventions (干预措施) can be designed,” researchers conclude. They say this discovery could help design policies to cut down problem trees. For example, instead of removing all trees near railway lines, it may be better to just cut down the species that contain tannins.

However, another solution may lie in stopping the tannins from the leaves interacting with the ions (离子) in the steel at all. “Interventions can be designed to target the specific reactions or chemicals,” the researchers say. At present they are still working on it.

It’s hard to stand out at work, when interactions are usually limited to email and video calls. There is, however, an easy way to boost your popularity and influence in your job, according to a new study.

The study “Amplifying (放大的) Voice in Organizations” shows that promoting a colleague’s ideas during a meeting can help strengthen your career. Researchers studied nearly 2,800 people and found that people who repeated or praised a colleague’s ideas during a meeting were admired more than those who talked only about their own ideas or stayed quiet. Dr. Kristin Bain, one of the study’s authors, tells CNBC that the research challenges the belief that people need to be aggressive or competitive to get ahead in their careers.

In the study, Bain and her team introduced the concept of amplification, which they defined as “the public endorsement of another person’s contribution”. The researchers tested the effectiveness of amplification through an experiment. Participants were employees of a non-profit organization who were trained to practice amplification at work for two weeks and record the results.

Overall, amplification proved to be an effective method: Both the “amplifier” and the “voicer” of the original ideas were viewed as highly respected and admired by their colleagues, thus making them more influential at the company, Bain notes. Amplified ideas were also seen as of higher quality than ideas that were not promoted by others.

To apply this method to your daily work life, Bain suggests listening carefully during meetings and intervening (干预) if a colleague’s ideas are ignored. Bain has experienced first-hand positive effects of amplification: When she first joined the RIT staff last year, she didn’t feel comfortable speaking up during meetings. “I put an idea into the chat of one of our video meetings, and my colleague who was much more social mentioned it to the group and said, ‘I think Kristin has a good point here.’ On a personal level, it feels great to have your words acknowledged, and it makes my co-worker look very enthusiastic.”

How the languages of the world appeared is largely a mystery. Considering that it might have taken thousands of years, it is attractive to see how deaf people can create novel sign languages unconsciously. Interestingly, children played an important role in the development of these novel languages. However, how exactly this happened has not been documented.

In a series of studies, researchers attempted to recreate exactly this process. Children were invited to stay in two different rooms and an online connection was set up between them.After a brief familiarization with the set- up, the researchers sneakily (偷偷地）turned off the sound and watched as the children found new ways of communicating that go beyond spoken language.

The children's task was to describe an image with different themes in a coordination game. With concrete things-like a hammer or a fork-children quickly found a solution by imitating the matching action, for example, eating, in a gesture. But the researchers repeatedly challenged the children with new, more abstract pictures. In the course of the study, the images to be described became more and more complex, which was also reflected in the gestures that the children produced. In order to communicate, the children invented separate gestures for actors and actions and began to combine them-thus creating a kind of small local grammar.

How does a language come into being? Based on the present study, the following steps appear reasonable: first, people create reference to actions and objects through signs that resemble things. The precondition for this is a common ground of experience between interaction partners. Partners also coordinate (配合）by imitating each other so that they use the same signs for the same things. The signs thus gain interpersonal and eventually common meaning. Over time, the relationships between the signs and things become more abstract and the meaning of the individual signs becomes more specific. Grammatical structures are gradually introduced when there is a need to communicate more complex facts. However, the most remarkable aspect of the current studies is that these processes can be observed under controlled circumstances and within 30 minutes.