【推荐1】In a TikTok video that has now collected nearly half a million views, the influencer Mady Maio describes taking a walk. But not just any walk: a silent one. For her, the 30-minute stroll was inspiring. She was resistant at first. “My anxiety could never disappear,” she said in the video. Ms. Maio described the first two minutes as mental “mayhem” that eventually gave way to a “flow state”. Her brain fog lifted. Ideas started popping into her head because she was “giving them space to enter”.

And a 2020 study in The Journal of Environmental Psychology found that a 30-minute walk in an urban park reduced the amount of time that people dwelled on negative thoughts. Walking has also been shown to improve creativity and help fend off depression.

But for some people, the idea of a silent walk might seem painful. One 2014 study found that, if left with no other option, people would shock themselves rather than sit alone with their thoughts. “Most people seem to prefer to be doing something rather than nothing, even if that something is negative,” the study authors wrote.

Walking, however, can make it more pleasant to spend time with ourselves, experts say. Erin C. Westgate, an assistant professor of psychology at the University of Florida in Gainesville who studies boredom, found in her research that being in transit, which included walking or riding public transportation, was one of the times when people most often reported having enjoyable thoughts.

If the idea of daydreaming seems luxurious, it may be because our attention spans have shrinked over the last two decades. Back in 2004, however, Dr. Mark found that people could spend an average of two and a half minutes on email before turning to another work task. “Continually flipping our attention from one task to another is draining,” Dr. Mark said.

But a silent walk can help replenish our “tank” so that we have a greater reserve of mental energy, she added. In other words, disconnecting for a while can actually help us perform better. In a future-oriented society we need opportunities to be satisfied with the here and now, Dr. Levy said, and drop the pressure to be productive. “There is great beauty and aliveness in the world outside of whatever it is we’re doing on our devices.” Dr. Levy said.

【推荐1】In the 16th century, it was not unusual to see armed men standing guard outside Britain’s dovecotes (鸽舍). They were not there to protect the pigeons living inside, but rather to prevent thieves from breaking in and stealing something far more valuable—the birds’ waste.

Chemists in mid-1500s Nuremburg had discovered that the birds’ waste was a rich source of saltpetre, a vital ingredient in the making of gunpowder. As a consequence, for several decades pigeon droppings were almost as valuable as silver. Moreover, waste gathered from the dovecotes was a rich fertiliser, particularly sought after by those with vineyards and orchards (果园).

The dovecote was not only a source of food and revenue in medieval times, but also a status symbol. The privilege of building or owning dovecotes was reserved for the upper class. The right was granted by the king. Those who were allowed to build a dovecote usually placed it in some conspicuous places, so that passersby could behold it.

However, the abundance of dovecotes across the British countryside was not universally welcomed. Even a small dovecote had nesting holes for 500 birds. Each day they flew off to stuff themselves on other people’s crops. By the middle of the 17th century, the disaster of pigeons was so great that poet John Milton voiced his fears that the dangerous doves would turn England into a desert.

Later, vast quantities of natural saltpetre were discovered in Chile and California, destroying the value of pigeon waste as a chemical resource. Keeping pigeons was no longer necessary nor profitable, nor even fashionable. During the 18th and 19th centuries, around 95 per cent of Britain’s dovecotes fell into disuse and were demolished.

Now homeless, the tens of thousands pigeons that had once lived in the dovecotes flew off to find somewhere else to live. A species that in the wild had nested on cliffs, the birds discovered that Britain’s rapidly growing towns and cities were full of the sort of rock-faces they liked to root into—humans called them “buildings”. And so these once noble and attractive birds settled there. Over time they’d become the wild urban pigeons that we know today.

【推荐2】Motorola set out a special training plan programme for children last week with the aim of developing children’s business skills and preparing them for a future as entrepreneurs.

Eighty-seven children aged between 12 and 16 from Beijing and Tianjin attended the one-week training programme called Youth Discovery directed by Motorola University’s (MU) instructors and marketing specialists. The children learned about dealing with a practical problem-marketing and worked out a marketing plan by themselves. Last week 26 children of Motorola employees in Tianjin completed their training in the MU-Tianjin Learning Center.

Through the training programme, children learned how to get information through different kinds of sources, determine end-user needs, make up messages of value to customers, and communicate using various means and equipment.

Educators acted only as team directors, providing children to discover their own answers. The children gave their solutions to Motorola’s management and their parents on the last day of the programme.

The children, most of whom were primary and middle school students, presented themselves freely. The students said that they preferred the open and practical way of learning. Youth Discovery, started by Motorola’s former president Robert Galvin, designed and carried out by Motorola University, aimed to bring the talents of young people into full play and encouraged them to discover how their skills can contribute to a team to help it reach an aim.

【推荐3】 Caribbean box jellyfish (水母) can learn to spot and avoid obstacles (障碍) despite lacking a central brain, according to a new study. This is the first evidence that jellyfish can do something called associative learning. The nervous systems of Caribbean box jellyfish are fairly simple, including four “rhopalia (视神经束)‌”on a jellyfish’s body, each of which has six “eyes‌”, by which the jellyfish judge a mangrove root’s distance based on how dark it looks compared to the water and make their way round it. In common waters, nearby roots have high contrast. Only distant roots fade into the background. But in murky waters, even near-by roots can blend into their surroundings and have low contrast. The researchers wondered if Caribbean box jellyfish could learn that low-contrast objects-which might at first seem distant-were actually close by.

To find out, the team put 12 jellyfish into a round water tank. The tank was surrounded by low-contrast gray and white stripes (条纹), which might appear to a jellyfish like roots in clear water. A camera filmed the animals for about seven minutes. At first, they seemed to see the gray stripes as distant roots and swam away, ending up bumping the tank wall. But those collisions (碰撞) seemed to lead the jellyfish to reconsider the stripes. Soon, the creatures treated the gray stripes more like close roots in murky water-and avoided them.

This suggests that the rhopalia alone can learn that seemingly distant, low-contrast objects are in fact close enough to avoid. That, in turn, hints that these nerve centers are behind Caribbean box jellyfish learning.

“That’s the coolest part of the paper,” says Ken Cheng, a biologist at Macquarie University, Sydney, Australia. “That gets us one step down into the wiring of how it works.” For Gaëlle Botton-Amiot, tracing learning to the rhopalia raises new questions. “They have four of these things in their bodies. So how does that work?‌” asks this neurobiologist. If a jellyfish loses one of its rhopalia, does it forget everything those eyes saw and the neurons had learned? Or do the other rhopalia remember it?

【推荐1】Climate change and increases in drought and rainstorms pose serious challenges to our water management. An international group of scientists have brought together a large body of research on water quality in rivers worldwide. The study shows that river water quality tends to worsen during extreme weather events. As these events become more often and severe due to climate change, ecosystem health and human access to safe water may be increasingly under threat.

The research led by Dr. Michelle van Vliet of Utrecht University analyzed 965 cases of river water quality changes during extreme weather such as drought, heatwaves, rainstorms, and flooding. The analysis shows that in most cases water quality tends to become worse during droughts and heatwaves (68%), rainstorms and floods (51%), and under long-term changes in climate (56%). During droughts, less water is available to dilute contaminants (稀释污染物), while rainstorms and floods generally result in more contaminants that run off from land to rivers and streams. Improvements or mixed responses in water quality are also reported for some cases, for example when increased transport of pollutants is offset (抵消) by more dilution during flood events.

Water quality changes are strongly driven by changes in water temperature. Land use and other human factors such as wastewater treatment also shape how this plays out. “Understanding the complex interplay between climate, land use, and human drivers, which together influence the sources and transport of pollutants is crucial,” says van Vliet. The research also calls for more data collection and studies of water quality in non-Western countries. “We need better monitoring of water quality in Africa and Asia. Most water quality studies now focus on rivers and streams in North America and Europe.”

The results of the study underline the urgent need for a better understanding of water quality changes during extreme weather events. It sounds an alarm to us. Only then will we be able to develop effective water management strategies that can safeguard our access to clean water and ensure ecosystem health under climate change and increasing weather extremes.

【推荐2】Ice from the massive Greenland ice sheet will eventually raise global sea level by at least 10 inches (27 meters) on its own, according to a recent study.

Zombie or doomed ice is ice that is still attached to thicker areas of ice, but is no longer getting fed by those larger glaciers. That’s because the parent glaciers are getting less replenishing snow, said study co-author William Colgan, a glaciologist at the Geological Survey of Denmark and Greenland.

“It’s dead ice. It’s just going to melt and disappear from the ice sheet regardless of what climate scenario we take now.” Colgan said in an interview. Jason Box, another glaciologist at the Greenland survey, also said it is “more like one foot in the grave”.

What scientists did for the study was look at the ice in balance. Normally, snowfall in the mountains in Greenland flows down and recharges and thickens the sides of glacicrs, balancing out what’s melting on the edges. But in the last few decades, there’s less replenishment and more melting, creating imbalance. Based on the ratio of what’s being added to what’s being lost, the study authors calculated that 3.3% of Greenland’s total ice volume will melt, contributing to at least ten inches in sea level rise, a global average.

This is the first time scientists calculated a minimum ice loss - and accompanying sea level rise - for Greenland, one of Earth’s two massive ice sheets that are slowly shrinking because of climate change from burning coal, oil and natural gas.

As for the timing of the committed melting, Colgan responded that the team doesn’t know how long it will take the doomed ice to melt, but making an educated guess, it would probably be by the end of this century or at least by 2150.

【推荐3】Adverse impacts on health due to extreme weather and vector-borne disease risks could increase in the United Kingdom (UK) under a warming climate, according to a report published on Monday by the UK Health Security Agency (UKHSA).

The report, written by 90 experts, is based on climate projections using a high-end warming scenario (可能发生的情况) or a “worst-case scenario” of approximately 4.3 degrees Celsius of warming by 2100. “Our changing climate poses one of the greatest health security and societal challenges, impacting everything from the air we breathe to the quality and availability of our food and water,” Isabel Oliver, chief scientific officer at UKHSA, said in a statement. The report estimates that there will be up to 10,000 deaths in the country by the 2050s as a result of extreme heat.

Based on a high-end warming scenario, the report anticipates a substantial surge in heat related deaths, with an increase of over 1.5 times by the 2030s and an over 12-fold rise by the 2070s. It also states that vector-borne diseases, such as chikungunya, dengue and Zika viruses, could become transmissible in London and other parts of the UK due to more Aedes albopictus (Asian tiger mosquitoes) and Culex mosquitoes.

The report also warns that more people will be at high risk of flooding in the future due to changing rainfall patterns.

“Action is needed now to adapt our policies, environments and our behaviors to secure health, well-being and livelihoods,” Oliver said, adding that much can be done to “avert (避免) and prevent” the impacts of climate change on health.

UKHSA, an executive agency sponsored by the Department of Health and Social Care, is responsible for planning, preventing and responding to external health threats.

This year is set to be the hottest year on record in human history, according to a report published by the United Nations World Meteorological Organization (WMO) at the 28th meeting of the Conference of the Parties to the UN Framework Convention on Climate Change.