A new study finds almost one third of the world’s population is overweight. Since 1980, obesity rates(肥胖率)in children and adults have doubled in 73 countries, making people more worried. And rates are increasing in many other countries. Obesity is increasing faster in children than adults in many nations, including Algeria, Turkey and Jordan, the report said. But the world's weight problem is growing in both rich and poor countries alike. Researchers say an increasing number of people are dying of related health problems in what they called a "disturbing global public health problem."
Researchers studied health information from 1980 through 2015. They examined obesity rates, average weight gain in 195 countries. They found that obesity rates are three times greater among youth and young adults in countries like China, Brazil and India. Almost 108 million children and more than 600 million adults were found to be overweight. Egypt had the highest number of overweight adults in 2015. Vietnam had the least. In the same year, the United States had the highest number of overweight children, and Bangladesh had the least.
Yet hunger remains a problem in many areas. The United Nations said that almost 800 million people, including 300 million children, go to bed hungry each night. Experts said poor diets and lack of physical activity are mainly to blame for the rising numbers of overweight people.
Growing populations have led to rising obesity rates in poor countries. Often, poor people will eat processed(加工的) foods instead of choosing a diet rich in vegetables.
The London-based Overseas Development Institute studied the price of food in five countries: Britain, Brazil, China, Mexico and South Korea. It found that the cost of processed foods like ice cream and hamburgers has fallen since 1990. But the cost of fresh fruits and vegetables has gone up.
【小题1】What do we know about obesity in the world?| A．It is worrying |
| B．It is given no attention |
| C．It has been successfully solved |
| D．It is more serious among old people |
| A．America | B．Vietnam |
| C．Egypt | D．Bangladesh |
| A．Hunger | B．Poor diet |
| C．Diets with vegetables | D．Eating too much fruit |
| A．It’s Important to Have a Balanced Diet |
| B．How Can We Lose Weight and Keep Fit? |
| C．Is It Necessary for Us to Eat Fresh Vegetables? |
| D．Nearly One Third of People in the World Are Overweight. |
17-year-old Dasia Taylor was named one of 40 finalists in the Regeneron Science Talent Search (STS), the nation’s most famous Science and math competition for high school seniors.
Dasia’s sutures (缝合线) work by changing color if the patients’ pH level changes, indicating an infection. pH is one of the most common parts of wound healing, Dasia said. It changes very quickly, so it’s one of the fastest ways to recognize infection.
So, she started experimenting with root vegetables. “I found that beet changed color at the perfect pH point,” says Taylor. “That’s perfect for an infected wound. And so, I was like, ‘Oh, okay. So beet is where it’s at’.” Beet provided the perfect dye for her invention, changing from bright red to dark purple when a surgical wound becomes infected. After more than a year of research, Taylor is working on getting her sutures patented.
She imagines these sutures being used in developing countries where they can save lives and money. “The goal of my project is to reduce the number of deadly surgical site infections in developing countries because developing countries suffer from the most number of deaths due to surgical site infections,” she said. “I was like there is no way that that should be happening. The equity part of my brain and all the work that I do around equity was like ‘That shouldn’t be happening. They should have the resources to save their citizens in their country.’ So, my goal is to work on that and make sure that it can actually discover those types of infections and stuff.” After graduation, Dasia hopes to attend Howard University, study political science and finally become a lawyer.
【小题1】How can a patient quickly know if a wound is infected?| A．By observing the pH test paper. |
| B．Through the doctors’ examination. |
| C．By looking at sutures’ color changing. |
| D．By observing how the wound changes. |
| A．Beet has the same pH level. | B．Beet can change color at different times. |
| C．Beet therapy is good for wound healing. | D．Beet can be used to help her with the invention. |
| A．She has won the invention patent. |
| B．She became the winner of the Regeneron STS. |
| C．She made contributions to surgical infection recognition. |
| D．She helped save lots of lives and money in developing countries. |
| A．Medical and health work. | B．Medical device development. |
| C．Something about the legal aid. | D．Medical and science research. |
Exercise is strongly associated with lowered risks for many types of cancer. At the same time, exercise involves biological stress, which typically leads to a short-term increase in inflammation(发炎) which can contribute to higher risks for many cancers.
Now, a new study in mice may offer some clues into the exercise-cancer paradox. It suggests that exercise may change how the immune system deals with cancer by boosting adrenaline（肾上腺素）, certain immune cells and other chemicals that, together, can reduce the severity of cancer or fight it off altogether.
To try to better understand how exercise can both elevate inflammation and simultaneously protect the body against cancer, scientists at the University of Copenhagen in Denmark and other institutions decided to closely examine what happens inside mice at high risk for the disease.
So, for the new study, they began by gathering a group of adult lab mice. These animals generally like to run.
The scientists then implanted melanoma (黑素瘤) skin cancer cells into the mice before providing half of them with running wheels in their cages while the other animals remained sedentary. After four weeks, far fewer of the runners had developed full-blown melanoma than the sedentary mice and those that had been diagnosed with the disease showed fewer and smaller lesions.
They drew blood from both the exercising and sedentary animals and cells from any tumors in both groups. As expected, they found much higher levels of the hormone adrenaline in the blood of the exercising animals, especially right after they had been working out on the wheels but also at other times of the day. The body releases adrenaline in response to almost any type of stressful experience, including exercise.
They also found higher levels of interleukin-6 in the blood of the runners. This is a substance that is released by working muscles and is believed to both increase and decrease inflammation in the body, depending on where and how it goes to work.
Perhaps most important, they found much higher numbers in the bloodstreams of runners than in the sedentary mice of a type of immune cell named natural killer cells that are known to be strong cancer fighters.
So the scientists repeated their original experiment multiple times, inducing cancer while allowing some mice to run and others to sit. In some of these follow-up experiments, the scientists injected the runners with a substance that blocked the production of adrenaline and gave sedentary animals large doses of added adrenaline.
What they now found was that when running mice could not produce adrenaline, they developed cancer at the same rate as the sedentary animals, while the sedentary animals that had been injected with extra adrenaline fought off their tumors better than other sitting mice.
More remarkably, the scientists determined that adrenaline seemed to be sending biochemical signals to some of the animals’ IL-6 cells, making them physiologically more alert, so that when a tumor began to develop in the affected animal, those IL-6 cells in turn activated the natural killer cells in the bloodstream and actually directed them to the tumors, like minute guide fish.
With these results, “we show that voluntary wheel running in mice can reduce the growth of tumors, and we have identified an exercise-dependent mobilization of natural killer cells as the underlying cause of this protection,” said Pernille Hojman, a researcher at the University of Copenhagen who oversaw the new study. It perhaps provides one more incentive for us to get up and move.
【小题1】In the first experiment, which one is the most important result the scientists found?
| A．Natural killer cells are much more in the bloodstreams of runners than in the sedentary mice. |
| B．Levels of interleukin-6 are higher in the blood of the runners than in the sedentary mice. |
| C．Exercise such as running seemed to help the mice fight against the cancer. |
| D．Adrenaline can reduce the severity of cancer or fight it off. |
| A．the hormone adrenaline has much higher levels in the blood of the exercising animals |
| B．how these elements in the runners — their increased adrenaline, IL-6, and natural killer immune cells fight against tumor |
| C．interleukin-6 can both increase and decrease inflammation in the body, depending on where and how it goes to work |
| D．what happens inside mice at high risk for the disease |
| A．adrenaline | B．interleukin-6 |
| C．natural killer cells | D．genes |
Have you ever always wanted to lie in bed and do totally nothing else, and just stay lazy and not worry about any of your responsibilities? We all feel lazy and uninspired from time to time.
You can’t cheer yourself up. Do you often struggle with feelings of unexplained loneliness, sadness, and hopelessness? Do you feel tired all the time and hardly have any energy?
You’ve lost interest in everything once you enjoyed.
If you or anyone you know is experiencing serious feelings of depression, don’t hesitate (犹豫).
| A．You just can’t get yourself out of it. |
| B．Your laziness isn’t caused by anything else. |
| C．We all have days when we are not ourselves. |
| D．Just give yourself a chance to open up yourself. |
| E．Reach out to a mental healthcare professional and get help. |
| F．And nothing you do seems to make you feel happier or better. |
| G．Obvious losing interest in activities is also a sign of depression. |
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