【推荐1】Think you have already reached your peak in life? You might want to think again. According to a new research, we're happiest at two periods in our lives — not just one. Researchers at the London School of Economics and Political Science asked 23,000 German volunteers aged 17 to 85 to rate their life satisfaction. Participants predicted how happy they would feel in five years, and then, after five years' time, reported back on how they actually felt.

Their results? Anything but unpleasant! The study found that happiness tends to follow a U-shaped curve over an individual's lifetime, with satisfaction reaching higher levels during the extremes of the study’s age range and swinging down in middle age. Plus, the researchers noted the two most important years when happiness peaks: ages 23 and 69.

As is shown in our daily life, it makes a lot of sense. In our early 20s, we're energetic and excited about the changes that come along with young age: new jobs, new places to travel, and new people to meet. By the time we reach our 60s and 70s, though, we have likely retired and can now find the time — not to mention the money — to book a flight to Hawaii at a moment's notice. After all, your 40+ years are a busy time filled with raising families, climbing the corporate ladder, and you know, it's the life in general.

Of course, that's all the more reason to find easy ways to be happier without really trying, regardless of your age! Experts recommend prioritizing (优先考虑) small yet rewarding tasks like taking a walk or spending time with family. Just remember, now you have one more reason to look forward to getting older: an increase in happiness!

【推荐2】A small robot may help children who are recovering from a long-term illnesses in the hospital or at home. These children may feel isolated from their friends and classmates. The robot takes their place at school. Through the robot, the children can hear their teachers and friends. They also can take part in class from wherever they are recovering.

Anyone who has had a long-term illness knows that recovering at home can be lonely. This is can be especially true of children. They may feel left out. Now, these children may have a high-tech friend to help feel less alone. That friend is a robot. The robot is called AV1. AV1 goes to school for a child who is homebound while recovering from a long-term illness. And the child's school friends must help. They carry the robot between classes and place the robot on the child's desk.

A Norwegian company called No Isolation created the robot. The co-founders of No Isolation are Karen Dolva and Marius Aabel. Dolva explains how the robot AV1 works. She says from home, the child uses a tablet or phone to start the robot. Then they use the same device to control the robot's movements. At school, the robot becomes the eyes, ears and voice of the child.

"So, it sits at the child's desk in the classroom and the child uses a tablet or a phone to start it, control its movement with touch, and talk through it. So it's the eyes and the ears and the voice at school."

The student can take part in classroom activities from wherever they are recovering --- whether at home or from a hospital bed. The robot is equipped with speakers, microphones and cameras that makes communicating easy.

【推荐3】Every few years, snowshoe hare (白靴兔) numbers in the Canadian Yukon climb to a peak. As hare populations increase, so do those of their predators (捕食者): lynxes and coyotes. Then hare populations fall and their predators start to die off. The cycle is a famous phenomenon among ecologists and has been studied since the 1920s.

In recent years, though, researchers have found hare numbers fall from their peak not just because predators eat too many of them. Long-lasting stress from living surrounded by killers causes mother hares to eat less food and bear fewer babies. The trauma (创伤) of living through such threats causes lasting changes in brain chemistry, keeping the hares from reproducing at normal levels.

And it’s not just snowshoe hares, as behavioral ecologists Liana Zanette and Michael Clinchy, who study what they call the ecology of fear, have shown. They’ve found that fear of predators can cause other wild mammals (哺乳动物) and songbirds to bear and raise fewer young. The offspring of frightened voles and song sparrows are less likely to succeed in reproducing. These findings add to a growing body of evidence showing that fearful experiences can have long-lasting effects on wildlife and suggesting that post-traumatic stress disorder (PTSD) is not only unique to humans, but shared among other creatures.

Rudy Boonstra, a population ecologist at the University of Toronto, sees the response of snowshoe hares as an adaptation that allows the animals to make the best of a bad situation. Animals stressed by many predators spend more time hiding and less time feeding, so they produce fewer young but that may allow more adult hares to survive to rebuild the population when the cycle starts again.

Despite the evidence that a wide range of animals experience the long-term impacts of extreme stress, some psychologists still hold their human-centric(以人为本的) view of PTSD. “It is defined in terms of human responses,” says neurobiologist David Diamond. “There is no biological measure - you can’t get a blood test that says someone has PTSD. This is a psychological disease, and that’s why I call it a human disorder. Because a rat can’t tell you how it feels.”