Researchers at a university in Hungary say there is truth to what many dog owners always believed. Dogs do understand what humans say.

The researchers made images of the brains of 13 dogs using a machine that records brain activity. The dogs were trained to lie down in the machine for seven minutes. During that time, they listened through headphones to their trainers 5 voices. Dog owners may think the news is not surprising. But scientists are impressed.

Brian Hare is a professor of evolutionary anthropology at Duke University. 【小题1】The brain imaging showed dogs processed words using the left side of their brains, just as humans do. They use the right side of their brains to understand tone and pitch. 【小题2】 Meaningful   words said in a neutral way did not have the same effect as the same words said in an encouraging way.

Attila Andies was the lead researcher on the project. “Dog brains care about both what we say and how we say it,” he said. 【小题3】 It’s because dogs have lived with people for a   long time. Andies said he thinks other animals probably can understand human language like dogs do. But those animals are not very interested in what humans have to say.

People reacted to the story on Facebook and Twitter. They said they always knew their pets could understand them. 【小题4】One reader from Virginia said she thought her dog could probably read her mind, too. Someone in California joked that

Often, research surrounding non-native — also referred to as invasive (入侵的) — species focuses on the negative impact on the environments they invade. Non-native species represent threats or even disasters; some are even famous for it. But according to a new study from Brown University, while the negative aspects of non-native life, including the increased risk of causing extinction to other species, are mainly talked about, the positives are not always addressed. Researchers say that non-native species also have the ability to increase biodiversity (生物多样性) within habitats.

As far as famously feared non-native species go, zebra mussels are high on the unwanted list. They originated in the waters of Eurasia and have grown to become a major issue in lakes and waterways across the Great Lakes, as well as in states such as Texas and California. In unnatural habitats, they reproduce rapidly, outcompeting native species for resources. Additionally, they attach themselves to hard surfaces, such as pipes and boats, costing millions to remove.

But for its research, the team decided to focus not only on non-native species’ negative impacts but also on what they can contribute to habitats. In forests, the earthworms have the ability to change the ecosystem negatively. However, when earthworms are present in agricultural land, there is a possibility for a 25-percent increase in the productivity of agricultural crops. As far as brown trout — a non-native species in New Zealand — are concerned, locals have embraced the fish, enjoying the economic and recreational benefits of fishing for the species and adding it to their local food.

Biologist Dov Sax, along with co-authors of the Brown University study, says that these benefits are not as uncommon as past research on invasive species may suggest.

“Our new paper argues that the positive impacts of non-native species are neither unexpected nor rare but instead common and important,” says Sax.

My folks bought their first house in the early 1940s after Dad got a better job in Marquette, Michigan. We lived just inside the city limits in what was still a rural area.

In the spring of 1948, when I was 6 years old, my parents bought a calf (小牛) to replace our cow, which had been killed the year before. So one day we drove to a local farm and returned with a white and brown calf we named Tubby.

We didn’t own a truck, so Tubby rode home in the backseat of Dad’s car with my 9-year-old brother Steve, and me. As you can imagine, the trip was a lot of fun for us kids.

Later that summer, Mom thought it would be cute to take a picture of me sitting on Tubby’s back. All went well unti1 the snap of the camera shutter sent Tubby charging off on a run, with me holding on for dear life. I lasted for about 30 feet before I hit the ground. Mom was quick enough to shoot a follow-up picture, so we had photos of me both on and off Tubby!

When summer had passed, the day arrived for poor Tubby to fill our freezer I must have been somewhere else with my Mom on the fateful day, because I have no memory of how it happened. All I knew was that the barn was empty, and that we had plenty of meat for dinners.

I hadn’t lived on a farm like my mother, so I didn’t understand that what happened to Tubby was not unusual. Livestock aren’t meant to be pets, and most farm kids know and accept that truth.

Whenever we had beef for dinner, I would tearfully, “Is this Tubby” This went on for a couple of weeks until Dad had finally had enough and declared, “No more cows!” That made me feel a little better about poor Tubby.