You've heard that plastic is polluting the oceans—between 4.8 and 12.7 million tonnes enter ocean ecosystems every year. But does one plastic straw or cup really make a difference? Artist Benjamin Von Wong wants you to know that it does. He builds massive sculptures out of plastic garbage, foreing viewers to re-examine their relationship to single-use plastic products.

At the beginning of the year, the artist built a piece called "Strawpocalypse," a pair of 10-foot-tall plastic waves, frozen mid-crash. Made of 168,000 plastic straws collected from several volunteer beach cleanups, the sculpture made its first appearance at the Estella Place shopping center in Ho Chi Minh City, Vietnam.

Just 9% of global plastic waste is recycled. Plastic straws are by no means the biggest source (来源)of plastic pollution, but they've recently come under fire because most people don't need them to drink with and, because of their small size and weight, they cannot be recycled. Every straw that' s part of Von Wong's artwork likely came from a drink that someone used for only a few minutes. Once the drink is gone, the straw will take centuries to disappear.

In a piece from 2018, Von Wong wanted to illustrate (说明) a specific statistic: Every 60 seconds, a truckload's worth of plastic enters the ocean. For this work, titled "Truckload of Plastic, "Von Wong and a group of volunteers collected more than 10,000 pieces of plastic, which were then tied together to look like they'd been dumped(倾倒)from a truck all at once.

Von Wong hopes that his work will also help pressure big companies to reduce their plastic footprint.

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.

The benefits of regular exercise are well documented but there's a new bonus to add to the ever-growing list. New researchers found that middle-aged women who were physically fit could be nearly 90 percent less likely to develop dementia (失智症) in later life and is they did, it came on a decade later than less sporty women.

Lead researcher Dr. Helena Horder, of the University of Gothenburg in Sweden, said: "These findings are exciting because it's possible that improving people's cardiovascular (心血管的) fitness in middle age could delay or even prevent them from developing dementia."

For the study, 191 women with an average age of 50 took a bicycle exercise test until they were exhausted to measure their peak (最大值的) cardiovascular capacity. The average peak workload was measured at 103 watts. A total of 40 women met the criteria for a high fitness level, or 120 watts or higher.

A total of 92 women were in the medium fitness category: and 59 women were in the low fitness category, defined as a peak workload of 80 watts or less, or having their exercise tests stopped because of high blood pressure, chest pain or other cardiovascular problems.

These women were then tested for dementia six times over the following four decades. During that time, 44 of the women developed dementia. Five percent of the highly fit women developed dementia, compared to 25 percent of the women with medium fitness and 32 percent of the women with low fitness

"However, this study does not show cause and effect between cardiovascular fitness and dementia it only shows an association. More research is needed to see if improved fitness could have a positive effect on the risk of dementia and also to look at when during a lifetime a high fitness level is most important" She also admitted that a relatively small number of women were studied, all of whom were form Sweden so the results might not be applicable to other groups.