As scientists in the Netherlands tried to figure out how to build a super flying robot, they learned from one of nature s flyers: the humble fruit fly(果蝇).And by building this robot, they've gained new insights into how the fly carries out one of its dangerous tasks.

    The robot is called the DelFly Nimble Its wingspan(冀展)is about a foot wide. It has four wings that can beat at 17 times per second, which appear very delicate because they're made of the same material as space blankets.

    In the previous designs, they always had a tail, like a traditional airplane tail, said the robots main designer Matej Karasek. He's based at the Micro Air Vehicle Laboratory at Delft University of Technology in the Netherlands, and he and his colleagues published their findings on Thursday in Science

    “In the previous generations", he said, "flapping wings drove the robot forward while the tail helped to guide and stabilize it. But now the DelFly Nimble is completely controlled by the wings. The challenge then was actually combine the control into the wing movement, and that's what we achieved, Karasek said

    In the latest generation. the wings can each move individually or rotate(旋转)around the body of the robot in order to maximize the machine s agility(灵活 ) The robot can remain in one place in the air for about five minutes on a full battery or fly for more than a kilometer"， Karasek said, "And because the scientists are controlling all the movements, they can use the robot to learn more about how fruit flies actually carry out their dangerous tasks, which has caught the attention of biologists.”

    In 2016, designer Liz Ciokajlo received a task from the Museum of Modern Art (Moma) in New York: revisit the Moon Boot, a fluffy-looking snowshoe inspired by the footwear used by the Apollo astronauts.

    Launched in 1972 at the height of the lunar missions, the Moon Boot is an icon of the 20th Century's “plastic age” and the museum administrators wanted a new take on it.

    Ciokajlo set out to reimagine it. She knew only a biomaterial would work in a “post-plastic age”, but the designer also wanted a new destination to inspire it. Our generation's space travel obsession is not the Moon, she thought, but the red planet Mars. And Mars allows you to really think outside of the box.

    The task led her to an amazing biomaterial that had already attracted the attention of engineers innovating m building materials and of top space agencies like NASA and ESA. Her final design, a tall, female, rough-looking boot, can be made on board a spaceship with almost only human sweat and a few fungus spores (真菌孢子), ideal for a seven-month trip to Mars with limited check-in luggage.

    This magic biomaterial is mycelium (菌丝体), the vegetative part of the fungus It looks like amass of white thread-like structures, each called hyphae. Collectively, these threads are called mycelium and are the largest part of the fungus.

    Mycelium has amazing properties. It is a great recycler, as it feeds off a substrate to create more material, and has the potential of almost limitless growth in the right conditions. It can endure more pressure than conventional concrete without breaking. It is a known insulator and fire-retardant and could even provide radiation protection on space missions.

    On Earth it's currently used to create ceiling panels, leather, packaging materials and building materials, but in outer space it stands out for its architectural potential, says artist and engineer Maurizio Montalti, who has teamed up with Ciokajlo.

    For her revisited boot, Ciokajlo wanted to use the human body as the source for some of the building materials and decided to employ sweat. Reusing sweat is not entirely new in space exploration but a novelty approach for footwear. She thinks it might make astronauts feel closer to home during the long journey to Mars.

    The design is still hypothetical, because the real boot submitted for Moma and currently in display at the London Design Museum did use mycelium but not human sweat, as their deadline was too tight, but the science checks out.

    The cost of living in countries like the U.S., Britain, Australia or France has skyrocketed (飞涨) in recent years. However, if you are willing to leave your country and explore life in other areas, there are many countries boasting an extremely cheap and low cost of living. Check out the following countries when planning your next move.

    Ecuador

    Ecuador is similar to the United States in many ways, and as a result has become a popular American getaway. They even use the U.S. dollar for their currency. In this country, it is cheaper to eat out every day than cook for yourself on a budget in the U.S. You can even buy a property for around $50,000 and hire someone to tend to it while you are away.

    Mexico

    Although the country is known for its poverty-ridden streets, there are many wealthier areas that provide every facility you might need. You can live off a mere $700 to $800 a month in Mexico, and this includes rent for a nice place, facilities, food, and any sightseeing.

    Argentina

    Argentina has been a popular tourist destination for many years. It has great restaurants, a rich history, and many places to explore. Not to mention, it is not very expensive to live there. A decent sized home can cost around $139,000, which is relatively cheap in relation to homes in the United States.

    Vietnam

    Vietnam has also become a popular tourist destination in recent years. There are many million dollar luxury homes by the beach, but you can find a modest flat or small home for around $25,000 to $50,000 if you search in the right areas.

    Many of us don't pay much attention to the importance of eye care. It is said that if you take care of your body, then you can surely be healthy. That is why our eyes should be given a lot of care. Natural eye care should be put in a number one place.

    There are several causes leading to poor eyesight like having not enough food, genes(基因)and aging(老化). Televisions, computers and reading are also the causes of having poor eyesight. If you happen to work in front of the computer, it is best to take a break every once in a while. You must also try your best to protect your eyes from harmful things. For example, sunglasses are not just for fashion but they can also serve as a great way to protect your eyesight from UV rays.

    Eating healthy food will do good to your eyesight. Remember that vitamins A, C and E are good for eyes. Try to eat food groups that have these vitamins. And you should do eye exercises which can protect your eyesight, too. All above are natural ways of eye care that help us to keep healthy eyes. Being happy all the time can be helpful to a person's eyesight, too. In a word, eye care is very important, no matter how old a person is.

Iman, the last Sumatran rhino(犀牛) in Malaysia, died in 2019 — bringing the endangered species one step closer to extinction. Now, Malaysian scientists are hoping to use tissues and cells from Iman and other dead rhinos to bring the population back.

"Before the three rhinos (the last survivors in Malaysia) died, we got their cells, and the cells are still alive — which is why I'm quite confident," Dr. Lokman said. "If we don't have any cells, or have just tissue that isn't living anymore, we wouldn't be able to do anything. But now we have a living thing that we can use. "

The cells came from the rhinos'hearts, lungs and brains. What is the most important is that the team collected stem cells (干细胞). One possible approach is to develop these stem cells into an egg (卵子) and sperm (精子), to create an embryo (胚胎) that will be placed into a surrogate mother (代孕母亲). She will likely be another rhino, either a Sumatran rhino from another country or another species. The other method is to take the egg of a surrogate animal, remove the nucleus (细胞核), and join it with a Sumatran rhino's body cell. This technique was famously used to clone Dolly the sheep in 1996. Dr. Lokman and his colleagues are trying both ways. The team is still in the early stages; next, they need to find a suitable surrogate female.

Sumatran rhinos are listed as critically endangered by the World Wildlife Fund. There are less than 80 alive in Indonesia and Thailand. The fall in the population was first caused by hunting. Later, the situation was worsened by the loss of habitats and human activity. Unfortunately, there are now only five remaining rhino species worldwide, and all are threatened. Some sub-species have already died out; the western black rhino was declared extinct in 2013. And it is a pity that the last male northern white rhino died in 2019.