What may well be the oldest metal coins in the world have been identified at an ancient abandoned city known as Guanzhuang in China. Like many Bronze Age (青铜时代) coins from the region, they were cast in the shape of spades (铲) with finely carved handles. These ancient coins existed during an in-between period between barter (以物易物) and money, when coins were a novel concept, but everybody knew that agricultural tools were valuable.

Reading about this incredible discovery, I kept thinking about the way modern people represent computer networks by describing machines as having “addresses”, like a house. We also talk about one computer using a “port” to send information to another computer, as if the data were a floating boat with destination. It’s as if we are in the Bronze Age of information technology, grasping desperately for real-world reference to transform our civilization.

Now consider what happened to spade coins. Over centuries. metalworkers made these coins into more abstract shapes. Some became almost human figures. Others’ handles were reduced to small half-circles. As spade coins grew more abstract. people carved them with number values and the locations where they were made. They became more like modern coins, flat and covered in writing. Looking at one of these later pieces, you would have no idea that they were once intended to look like a spade.

This makes me wonder if we will develop an entirely new set of symbols that allow us to interact with our digital information more smoothly.

Taking spade coins as our guide, we can guess that far-future computer networks will no longer contain any recognizable references to houses. But they still might bring some of the ideas we associate with home to our mind. In fact, computer networks — if they still exist at all — are likely to be almost the indispensable part of our houses and cities, their sensors inset (嵌入) with walls and roads. Our network addresses might actually be the same as our street addresses. If climate change leads to floods, our mobile devices might look more like boats than phones, assisting us to land.

My point is that the metaphors (比喻) of the information age aren’t random. Mobile devices do offer us comfort after a long day at work. In some sense, our desire to settle on the shores of data lakes could change the way we understand home, as well as how we build computers. So as we cast our minds forward, we have to think about what new abstractions will go along with our information technology. Perhaps the one thing we count on is that humans will still appreciate the comforts of home.

Runners need to move 15 per cent faster on a treadmill (跑步机) to burn the same number of calories as jogging outdoors, research reveals. Researchers found running on treadmills significantly reduces the amount of oxygen joggers use. 【小题1】

Researchers from Milan University analysed the difference between running outdoors and on a treadmill in 15 physically fit males with an average age of 21. 【小题2】. And it was followed by 30 seconds of recovery for a total of 15 minutes both outdoors and on a treadmill. Oxygen use and exercise intensity were measured after both types of running.

The results revealed that when on a treadmill, runners use significantly lower amounts of oxygen, suggesting less effort is required. 【小题3】

【小题4】

A 15 per cent increase in running speed during a high intermittent (间歇的) intensity treadmill training session is the optimal solution to reach the same physiological responses as an outdoor training session.

【小题5】 But the previous research suggests the moving belt of a treadmill propels (推进) joggers forward, causing them to move faster. Exercising indoors also means gym-goers do not have to fight with steep hills or wind resistance. Michael Silverman, director of rehabilitation and wellness at Northern Westchester Hospital in New York, said, “Outdoors, you are changing surfaces constantly, fighting the wind, and making quick and sudden starts and stops, which will lead to increased caloric burn.”

A new Northwestern University study reaffirms the importance of getting a good night’s sleep. By examining fruit flies’ brain activity and behavior, the researchers found that deep sleep has the power to clear waste from the brain. This waste potentially includes poisonous proteins that may lead to neurodegenerative (神经退化) diseases. “Waste clearance could be important, in general, for maintaining brain health or for preventing neurodegenerative diseases,” said Dr. Allada, senior author of the study. “Waste clearance may occur during wake and sleep but is greatly strengthened during deep sleep.”

Although fruit flies seem very different from humans, the neurons (神经元) that govern flies’ sleep-wake cycles are strikingly similar to our own. For this reason, fruit flies have become a well-studied model organism for sleep and neurodegenerative diseases.

In this current study, Allada and his team examined Proboscis (针状喙) Extension Sleep, a deep-sleep stage in fruit flies, which is similar to deep, slow-wave sleep in humans. The researchers discovered that, during this stage fruit flies repeatedly extend and move back their proboscises. “This kind of movement moves fluids possibly to the fly version of kidneys (肾),” Allada said. “Our study shows that this promotes waste clearance and aids in injury recovery.”

When Allada’s team disturbed flies’ deep sleep, the flies were less able to clear the waste from their systems and were more likely to be influenced by injuries.

Allada said this study brings us closer to understanding the mystery of why all organisms need sleep. All animals, especially those in the wild, are incredibly weak when they sleep, but research increasingly shows that the benefits of sleep, including crucial waste removal, are greater than this increased weakness.