A handshake is one of the most common ways to greet others, but US President Donald Trump's unusual method has been put under the microscope lately.

    Much like an arm wrestler in a match, the recently-elected leader has a habit of yanking (猛拉) people's hands toward himself during handshakes. And while a typical handshake is only brief, the one between him and Japanese Prime Minister Shinzo Abe on Feb 10 lasted a full 19 seconds.

    Simply having a strong hand is not the explanation here. According to Darren Stanton, a body language expert from the UK, while handshakes are usually an exchange of kindness, Trump uses his as a way to show power and control, regardless of how uncomfortable it makes people. “It is as if to say, 'Hey, I'm in charge, don't mess with me,' ” Stanton told The Independent.

    Apart from Trump's “yank-shake”, there are other ways people display power with their hands. At business talks or political meetings, for example, some people may rotate (旋转) their wrists during handshakes so that their hand ends up on top instead of underneath. Some may squeeze so hard that it leaves the other person's hand in pain.

    According to Stanton, by pulling people into his personal space, Trump is also testing whether they are willing to cooperate with him. “For example, if someone was resistant to being yanked towards him and stood their ground, he would know that he has work to do with them before he got what he wanted,” Stanton told Express.

    This is probably why on Feb 13 when Canadian Prime Minister Justin Trudeau visited the White House, all eyes were on how he was going to handle Trump's handshake. Fortunately, Trudeau managed to avoid the embarrassment by grabbing Trump's shoulder to stop himself being pulled in. Afterward, some Twitter users wrote that this proved Trudeau's strong leadership, with one even calling the moment “one of Canada's greatest victories”.

    Vice magazine summed up the exchange between the two leaders as: “... no regular handshake. This was the first shot in a bloodless war.”

    Our risk of cancer rises dramatically as we age. So it makes sense that the elderly should be routinely screened for new tumors — or doesn't it?

    While such vigilant(警觉的) tracking of cancer is a good thing in general, researchers are increasingly questioning whether all of this testing is necessary for the elderly. With the percentage of people over age 65 expected to nearly double by 2050, it's important to weigh the health benefits of screening against the risks and costs of routine testing.

    In many cases, screening can lead to additional biopsies(活检) and surgeries to remove cancer, which can cause side effects, while the cancers themselves may be slow-growing and may not pose serious health problems in patients' remaining years. But the message that everyone must screen for cancer has become so ingrained(根深蒂固的) that when health care experts recommended that women under 50 and over 74 stop screening for breast cancer, it caused a riotous reaction among doctors, patients and advocacy groups.

    It's hard to uproot deeply held beliefs about cancer screening with scientific data. Certainly, there are people over age 75 who have had cancers detected by routine screening, and gained several extra years of life because of treatment. And clearly, people over age 75 who have other risk factors for cancer, such as a family history or prior personal experience with the disease, should continue to get screened regularly. But for the remainder, the risk of cancer, while increased at the end of life, must be balanced with other factors like remaining life expectancy(预期寿命).

    A recent study suggests that doctors start to make more objective decisions about who will truly benefit from screening—especially considering the explosion of the elderly that will soon swell our population.

    It's not an easy calculation to make, but one that make sense for the whole patient. Dr. Otis Brawley said, “Many doctors are ordering these tests purely to cover themselves. We need to think about the rational(合理的) use of health care and stop talking about the rationing of health care.”

    That means making some difficult decisions with elderly patients, and going against the misguided belief that when it comes to health care, more is always better.

    Hello,everybody.Welcome to surf on a new Web site—SCIENCE NEWS FOR KIDS!

    Our goal is to offer timely items of interest to kids,accompanied by suggestions for hands on activities,books, articles,Web resources,and other useful materials.

    Our emphasis is on making the Web site attractive by offering kids opportunities to comment on and grade the subject matter,get ideas for science projects,and try out math puzzles.At the same time,we offer teachers creative ways of using science news in their classrooms.

    The Science News for Kids Web site,supported by several corporations and foundations,strengthens the usefulness of Science News in the middle－school classroom and offers entertaining reading and activities for students interested in science.

    A section of the Science News for Kids Web site is devoted to particular interests.At present,we have six such zones: a weekly brainteaser（难题）for those who enjoy solving and inventing puzzles (PuzzleZone),entertaining science－fiction composition exercises for those interested in writing (SciFiZone),and weekly science short description along with science project ideas and tips (ScienceFairZone).The GameZone contains a small selection of logic and memory games.The TeacherZone has materials,including question sheets related to the feature article of the week,so that teachers can bring science news topics to the classroom.The LabZone features a weekly hands on activity or science project idea.In the future,we might add additional zones,for example,for kids interested in robotics,the environment,computers,math,or veterinary（兽医的）medicine and animals.

    Contact us at editor@snkids.com.         Science News for Kids            1719 N Street,N.W.

    Washington,DC 20036                 Phone :202-785-2255             Fax: 202-659-0365

    People aren't walking any more-if they can figure out a way to avoid it.

    I felt superior about this matter until the other day I took my car to mail a small parcel. The journey is a matter of 281 steps. But I used the car. And I wasn't in any hurry, either. I had merely become one more victim of a national sickness: motorosis.

    It is an illness to which T had thought myself immune(免疫的), for I was bred in the tradition of going to places on my own two legs. At that time, we regarded 25 miles as a good day's walk and the ability to cover such a distance in ten hours as a sign of strength and skill. It did not occur to us that walking was a hardship. And the effect was lasting. When I was 45 years old I raced—and beat-a teenage football player the 168 steps up the Statue of Liberty.

    Such enterprises today are regarded by many middle-aged persons as bad for the heart. But a well-known British physician, Sir Adolphe Abrahams, pointed out recently that hearts and bodies need proper exercise. A person who avoids exercise is more likely to have illness than one who exercises regularly. And walking is an ideal form of exercise-the most familiar and natural of all.

    It was Henry Thoreau who showed mankind the richness of going on foot. The man walking can learn the trees, flowers, insects, birds and animals, the significance of seasons, the very feel of himself as a living creature in a living world. He cannot learn in a car.

    The car is convenient means of transport, but we have made it our way of life. Many people don't dare to approach Nature any more; to them the world they were born to enjoy is all threat. To them security is a steel river thundering on a concrete (混凝土) road. And much of their thinking takes place while waiting for the traffic to turn green.

    I say that the green of forests is the mind's best light. And none but the man on foot can evaluate what is basic and everlasting.

    Sweat (汗水)rail its way down my cheek. It was hot, but the air was still and wet. One final play and the State Softball Championship was ours.

    I looked towards people who were watching the game. Sure enough, I found my mom. I always wished my dad were here. The farm needed his full attention, but I did not care.

    Finally, we won! State Champs! I let out a scream of happiness, fall of tears. My mom made a “V” to celebrate my success and smiled. I smiled back at her.

    We all received medals (奖牌), but I cannot remember any of it. I concentrated my thoughts on my dad, I ran to my mom, asking for her cell phone. I had to tell my dad about the happiest day of my life, and complained (抱怨）about how he did not care.

    The phone rang twice, and no one answered. My heart sank with sadness, but I tried again anyway.

    “Hello?” My dad answered.

    “Dad!” I cried. “We won State!” Silence.

    “Dad?” I could hear something on the other end. “Are you crying?”

    “I'm just really happy for you, Meggie,” he said. “And I'm sorry I couldn't be there.”

    An apology（抱歉）was all I needed. I hung up the phone feeling relaxed, and I began to understand how it must feel to be a father. I forgave him for never being there. He worked so I could play. My father loved me enough to let me experience life^ happiest moments without him.

A recent study by UK researchers has shed light on a phenomenon termed "plant blindness," which contributes to the widespread but mistaken belief that plants are perceived as less vibrant or alive compared to animals.

It was not established that plant blindness is an innate trait; instead, the root cause appears to be the significantly diminished interaction with the natural world in societies that have become highly urbanized. The research indicates that a decrease in prior exposure to plants leads to a cycle of inattention.

Urban cultures exhibit a well-documented incidence of plant blindness. Children are often observed to regard plants as less significant than animals, especially during their early years, and they have difficulty recognizing a diverse range of plant species. Both educators and students have reported varying levels of knowledge about plants, with primary school teachers lacking a background in science being particularly affected. In contrast, older individuals tend to possess greater plant knowledge, likely due to their increased participation in outdoor activities.

Thirty-five studies have concluded that the process of urbanization or modernization has had a negative impact on people's understanding of plants. The value of plant gathering has diminished due to an increased reliance on urban services and a cash-based economy. Additionally, the time available for outdoor activities has been curtailed by work and school commitments. These factors have also reduced family time, which in turn has adversely affected the oral transmission of plant knowledge to younger and older family members.

Stagg has suggested that rather than a cognitive impediment to the visual recognition of plants, individuals residing in highly industrialized nations suffer from a lack of attention to plants due to a reduction in relevant exposure.

To disrupt the cycle of plant inattention, Stagg emphasizes the importance of exposing people to diverse ecosystems and demonstrating the direct benefits of plants to humans, as opposed to the indirect benefits derived from their industrial use or advantages to distant, traditional communities. Engaging with edible and practical plants in local settings can be instrumental in this regard. The level of botanical knowledge among younger generations is directly linked to their perception of the usefulness of such knowledge in their lives.