【推荐1】Owning a pet, like a dog or a cat, especially for five years or more, may be linked to slower cognitive decline (认知衰退) in older adults, according to a new study.

“Previous studies have suggested that the human-animal link may have health benefits like decreasing blood pressure and stress,” said the study author Tiffany Braley. “Our results suggest raising pet may also be protective against cognitive decline.”

The study looked at cognitive data from 1.369 senior adults with an average age of 65 who had normal cognitive skills at the start of the study. A total of 53% owned pets and 32% were long-term pet owners who owned pets for five years or more.

Researchers used data from the Health and Retirement Study. In that study, people were given several cognitive tests. Researchers used those cognitive tests to record cognitive score for each person, ranging from 0 to 27. The score included common tests of subtraction (减法), number counting and word memory. Researchers then used participants’ cognitive scores to judge the connections between years of pet ownership and cognitive function.

Over six years, the cognitive scores decreased at a slower rate in pet owners. This difference was stronger among long-term pet owners. Considering other factors known to affect cognitive function, the study showed that long-term pet owners usually had a higher cognitive score compared to non-pet owners. The researchers also found that the cognitive benefits connected with longer pet ownership were stronger for college educated adults and men.

“As stress can negatively affect cognitive function, the possible stress-reducing effects of pet ownership could provide a proper reason for our findings,” said Braley.

【推荐2】In the amazing natural environment, some birds capture our imaginations. We point to swans as an example of true love since they mate for life. We admire eagles for their power to fly at high altitudes. Owls have been associated with wisdom since the ancient Greeks used an owl for the symbol of Athena, goddess of wisdom. White storks (白鹳), too, deserve high praises, which have been featured in legends since ancient times.

Storks are migratory (迁徙的) creatures which winter in tropical Africa. In spring they make the exhausting trip back to Central Europe, arriving from the end of February to mid-April at the previous year’s nesting site. The Germans and Dutch often constructed high platforms on their roofs for storks to build nests on because they believed storks brought good luck. Germans also believe storks found babies in caves and delivered them to new parents. The parents would let the storks know they wanted a baby by leaving candy on a windowsill (窗台).

A romantic stork story has touched people around the world, especially people in Croatia. In 1993, a retired man named Vokic came upon a wounded female stork near a small Croatian village. Vokic took her home, named her Malena, fed her and kept her company. They even watched TV together. In 2002, Malena acquired a mate named Klepetan. Every fall for 19 years, Klepetan would migrate to South Africa and then return to Malena in Croatia each spring. People would anxiously await the news of Klepetan’s return. Over the years the long-legged couple raised 66 chicks. Vokic built nests for them and helped out with the chicks. Sadly, Malena passed away in 2021, and Croatians mourned. Vokic’s hope is that Klepetan will return this year and perhaps find a new mate.

Malena and Klepetan’s story makes it appear that storks are monogamous (一夫一妻的), but that isn’t always true. They can change mates after migration. Whether storks mate for life or not, they are beloved by many.

【推荐3】Teaching Your Dog Tricks

Dogs are social animals who enjoy spending time with us, and training is a wonderful way to create quality moments together. Teaching tricks provides a great mental workout for your dog.     1     Teaching your dog tricks should always be fun and rewarding for you both. It is entertaining and lets you show friends just how clever your dog is.     2    

Start the moment you bring your puppy home. Most puppies are very enthusiastic and eager to learn, and you will be amazed at what you can achieve together if you commit to regular training.     3     Older dogs will also benefit from the mental stimulation (刺激) of learning tricks and it can further strengthen your bond.

Train when you are in a good mood. Training should be a positive experience for your dog, so only train when you are not tired or distracted (分心). Put your mobile phone away so you can focus without distractions.

    4     A dog has a short attention period, so you should train when it is focused. Most dogs are eager for food before their meals, so this is usually a good time for training. Keep sessions short — five to ten minutes, a couple of times a day, is enough to make progress.

    5     Many tricks will require your dog to know the basics such as Sit, Stay and Drop before you can progress. For example, you can’t teach your dog to shake paws without it knowing how to sit, or to roll over without it knowing how to drop.

【推荐2】Over the years, NASA has successfully sent several rovers (飞行器) to Mars. While the science laboratories continue to provide important information on the Red Planet, they keep the space exploration rovers staying close to the original landing place.To get a more comprehensive (详尽的) view of Mars, the US Space Agency plans to make a small test helicopter with the Mars 2020 Rover, which will be sent off in July 2020.

The football-sized “marscopter” weighs about four pounds. It can fly at about ten times the speed of helicopters on Earth. The light weight and fast speed are important for the helicopter to be able to fly in the thin Mars atmosphere, which is about just one percent of that of Earth. “To make it fly in that thin Mars atmosphere, we had to make everything ready, and make it as light as possible while being as strong and powerful as it can possibly be. “Mimi Aung, Mars helicopter project manager, said in a meeting.

Upon landing on the Red Planet, the Mars 2020 Rover will find a proper location to send of the helicopter. The helicopter will start with a short climb, no higher than 10 feet, and hover (盘旋) for just 30 seconds before landing back on the Mars surface. If all goes well, five more flights of longer distances, for 90 seconds each, will be conducted over the next 30 days. The short journeys will be recorded by a small camera and sent back to the scientists on Earth.

If the plan goes on well, the first helicopter to fly in another world, will open up a whole new way to explore Mars. The Mars helicopter's first flight will be a great invention. For those of us whose research is about flight, that would be a wonderful, historic moment.

【推荐3】Faced with changing product prices and pressure to be more efficient and environmentally friendly, farmer Jumie Butler is trying out a new worker on his 450-acre farm in England’s Hampshire countryside.

Carefully inspecting Butler’s winter crops for weeds (杂草) and pests, the laborer doesn’t complain or even sweat. That’s because it’s a four-wheeled robot named “Tom” that uses GPS, artificial intelligence (AI) and smartphone technology to digitally map the field.

Tom’s creator is the Small Robot Company. It works to transform production in an industry that is under economic stress. due to market pressures to keep. food. cheap, a rising global population and the uncertainties of climate change. Most robots are still only being tested, but they give an idea how automation (自动化) will spread into rural areas.

“If we can keep our costs to an absolute minimum by being on the leading edge of technologies as one method of doing that, then that’s a really, really good thing,” said Butler, one of the 20 British farmers that are enlisted in a year-long trial.

This year, the economy will start trials for two more robots, Dick and Harry. Dick will deliver fertilizer directly to soil around roots, instead of wasteful spraying (喷洒). Harry will put seeds into the earth at the same depth and spacing.

The aim is to cut down a great deal on fertilizer and pesticide (杀虫剂) use to lower costs and increase profits for struggling farmers. As such, it not only helps economically, but it also lowers the environmental effect of farming.

“What we’re doing is something that people can’t do,” said Ben Scott-Robinson, co-founder of the Small Robot Company. “It’s not physically possible for a farmer to go round and check each individual plant and then treat that plant individually. That’s only possible when you have something as tireless as a robot and as focused and accurate as AI to be able to achieve that.”

【推荐1】

A team of students from Stanford University are making efforts to launch a satellite powered exclusively by water into orbit (轨道) around the Mars.

These creative students are now attending a competition called the Future Space Challenge, which is held annually by NASA, the American space agency to find more talents in space. The Stanford team names itself the SuperLunar Explorers.

The principle behind the competition is simple: to think, design, build and launch “qualified small satellites.” NASA officials required that the satellites must be able to perform “advanced operations near and beyond the moon.”

Twenty teams are competing for the championship. But the SuperLunar Explorer satellites are totally different. They use only water to power their spacecraft, which has never been done before.

Such a novel idea for a water-powered satellite came from Peckon Lewis, who works at Stanford University now, who once worked as NASA’s chief technologist. He has always been wondering whether something other than rockets can be used to push spacecraft beyond earth. “A lot of things we send into space these days is with the help of rockets -- the only way we get anything into space,” he said, in a Stanford press release. “But if we could try something that has been already there? If we could do that, if we could re-fuel spacecraft while they’re already in space...”

The spacecraft is designed with the shape of the English letter L. It is about 30 centimeters in length, and the two pieces are interconnected. The lower part of the satellite is designed to store water, which will be separated by solar panel into two elements: hydrogen and oxygen. When one combines hydrogen and oxygen with a spark (火花), an explosion was caused. This provides a forward movement, known as thrust.

The SuperLunar Explorer team has devised a special way to guide its spacecraft. The idea is to imitate how sailors in ancient times used the moon, sun and stars to fix their position on the oceans. The satellite is equipped with cameras in all directions. The cameras will shoot pictures of the sun, the earth and the moon and compare their positions and their sizes. Based on where the sun, moon and earth are at any given time, the SuperLunar Explorers will find their position in a mathematic way.

The Future Space Challenge is divided into four rounds. The Stanford team has been among the top four competitors during rounds one and two. The winners of the fourth round will be publicized in about a month. The final three winners will be announced in early 2023. They will get to ride on NASA’s space launch system in early 2024.

【推荐3】BBYY, as the adult female was known, made a wild dash of more than 388 kilometers in 49 days—the longest distance ever recorded among hares, rabbits or any other relatives—researchers report online December 22 in Ecology.

“To think that such a small animal living under such extreme conditions averaged about eight kilometers per day across seven weeks is truly amazing,” says Joel Berger, a scientist at Colorado State University in Fort Collins.

Arctic hares, also known as North-Pole hares—which weigh more or less the same as house cats, about four kilograms—are desirable targets for foxes and wolves on the tundra (苔原). Given the hares’ important role in the Arctic food chain, scientist Dominique Berteaux wanted to know how the animals move across the dry landscape where very few plants can grow.

In 2019, Berteaux and colleagues fixed satellite tracking rings on 25 hares caught near the northern tip of Ellesmere Island in Nunavut, Canada. As the hares quickly ran away, the researchers had no idea the creatures were beginning a mind-blowing journey across the tundra, Berteaux says. That’s because hares and their relatives, typically spend their lives within a familiar area where food is plentiful and easy to find.

The Arctic hares behaved quite differently, with most traveling anywhere between 113 and 310 kilometers. None came close to BBYY, who died of unknown causes about a month after reaching her final destination.

For a hare to complete such a dangerous journey, it must balance the need to find food without becoming food, says Dennis Murray, a scientist. That makes BBYY’s adventure even more impressive, he says.

Berteaux and colleagues hope data from BBYY and the other hares can help shape conservation strategies for the desert system near the North Pole. But even at this early stage, it’s exciting to find “something unknown in an animal that we thought we knew quite well,” Berteaux says.