【推荐1】The “diet” in diet drinks may be a false promise for some soda lovers. A study published recently in JAMA Network Open adds to the evidence that drinks made with sucralose (蔗糖素) may stimulate the appetite, at least among some people.

“We found that females and people with obesity (肥胖)had greater brain reward activity” after consuming the artificial sweetener, says study author Katie Page, “What was most surprising was the impact of body weight and biological sex. They were very important factors in the way that the brain responded to the artificial sweetener.”

Both groups also had a reduction in the hormone that inhibits (抑制) appetite, and they ate more food after they consumed drinks with sucralose, compared with after regular sugar-sweetened drinks. In contrast, the study found males and people of healthy weight did not have an increase. in either brain reward activity or hunger response, suggesting they’re not affected in the same way.

Page and her team measured the response to diet soda in three ways. They used brain images of the 74 study participants to record the activities of parts of the brain linked to appetite. They used blood samples to measure blood sugar and hormones that can drive hunger. And they also tracked how much participants ate at a buffet table at the end of each study session.

“These results are consistent with patterns that we’ve actually seen in my lab in animal studies,” says Susan Swithers, a behavioral scientist at Purdue University.

“You are supposed to get sugar after something tastes sweet. Your body has been accustomed to that,” explains Swithers. But diet soda may lead to a disconnect. The sugar never arrives, and “that could decrease the body’s efficiency in metabolizing (新陈代谢)sugar the next time.”

【推荐2】February 13, 2022, marked the 25th anniversary (纪念日) of the Great LEGO Spill — the worst toy-related environmental disaster of all time. On this important day in 1997, the Tokio Express was hit by a huge, 28-foot high wave off the United Kingdom’s southwestern coast, tilting the ship by 60 degrees and causing it to drop 62 containers into the sea. One was filled with about 5 million colorful LEGO bricks!

Shortly after the incident, LECO pieces began washing ashore the beautiful beaches of Cornwall and Devon in southwest England. Many locals rushed to hunt for the toys. Cornwall resident Tracey Williams was among the thousands of locals that searched the beaches regularly to find the little sea-themed pieces.

In 2010 Williams moved to Cornwall and came across some LEGO pieces on her first trip to the beach. Wondering where else they had been found, she created a Facebook group. Called “Lego Lost at Sea”, it allowed her and hundreds of other collectors to share their discoveries. As it turned out, the LEGO bricks were not just washing ashore English beaches. They had also been found in Wales, Ireland, the Channel Islands, France, Belgium, and Holland, showing just how far ocean currents had carried them.

“What we’re finding now are the pieces that sank as well as the pieces that floated,” Williams says. “It’s providing us with an insight into what happens to plastic in the ocean, how far it drifts (漂移) — both on the surface of the ocean and also along the seabed—and what happens to it as it breaks down.”

No one knows when the LEGO bricks will stop appearing on the beaches. But one thing is for sure, that is, the plastic pieces will be around for centuries. A 2020 study analyzing the structure of the washed-up LEGO bricks concluded that the five million pieces could take as long as 1,300 years to degrade (降解) completely. And like all plastic products, the iconic toys will never entirely disappear. Instead, they will break down into tiny “microplastics” and be eaten by ocean animals. They will make their way up the food chain to humans.

【推荐3】The start of a new school year brings lots of changes. One is the need to wake up earlier. Depending on when school starts, getting up early can turn teens into “zombies(僵尸),” studies have shown. But when schools start later, teens get to class on time and find it easier to stay awake, a new study finds.

For years, researchers and doctors have pushed for later high school start times. Experts recommend kids and teens get an average of nine hours of sleep every day. As children reach their teen years, the clocks inside bodies that control their sleep timing naturally change. This makes it hard for them to fall asleep before 11:00p.m. So when they have to get up in time for an 8:00 a. m. class, they’re missing out on valuable sleep time.

Knowing this , schools in several places have begun to change their start times. Ressearchers have now begun looking at how this affects students. When all schools started early, many teens reported struggling to get enough sleep. After the change in start time, students in the late-start schools were less likely to oversleep. Compared to students at the early-start schools , they also were less likely to be late for class. Best of all, they reported felling less sleepy during the day. These changes reflected their getting more sleeping time. That much extra sleep on a daily basis seemed to have made a difference in these students’ lives. Researchers believe the extra sleep will make it easier for students to actively take part in school.

Sleep is truly important, even though we live in a culture that acts like it’s optional(可选择的). It’s easier to focus on school, be a good friend and do well in sports when you aren’t tired out.

【推荐1】We’ve all been told that different types of fruits and vegetables have different benefits that help us maintain our health. A new international study has found that eating one fruit regularly can help reduce the risk of cancer, among those people who have a high risk of developing certain cancers.

The research which followed almost 1000 patients with Lynch syndrome-a genetic condition that makes people predisposed to orange of cancers found that a regular intake of resistant starch(抗酶解淀粉)could have a major preventative effect on the risk of cancer. Here’s what you need to know about how eating bananas can help reduce risk of cancer.

Resistant starch is a type of carbohydrate(碳水化合物)which feeds beneficial gut bacteria. It is found in green bananas. By eating green bananas your body gets a regular dose of resistant starch, which has been found to reduce risk of cancers in some parts of the body by more than half, according to the new research. The study, which was published in Cancer Prevention Research, was led by experts at the Universities of Newcastle and Leeds. It found that resistant starch, if taken regularly for an average of two years, had a positive effect on some cancers, which can be difficult to detect.

John Mather, a professor at Newcastle University explained:“Resistant starch acts in effect, like dietary fibre in your digestive system. This type of starch has several health benefits and fewer calories than regular starch.”

Besides green bananas, resistant starch is also found in foods such as peas, oats, cereal, beans and other starchy foods. You can also take resistant starch as a powder supplement.

In terms of bananas, experts recommend that eating one banana daily is the equivalent of one dose of resistant starch. The trick is to eat the bananas before they become too ripe or soft.

【推荐2】As home gardeners in the US page through seed catalogs (目录册) and pick out their favorite plants this week, there’s a new seed that has never been available to them before: a purple tomato. It is the first genetically engineered food crop to be directly marketed to home gardeners and the seeds went on sale Saturday.

The lending scientist behind the tomato is Cathie Martin. About 20 years ago, she set out to create a transgenic (转基因的) tomato, using DNA from a purple snapdragon, which is an unrelated eatable flower. Her goal was to develop a tomato with high levels of anthocyanins, chemicals that give blueberries, blackberries, eggplant and purple cabbage their color. Research has shown that anthocyanins also have anti-cancer and anti-aging effects.

“It’s normal for tomatoes to make these healthy chemicals. But they typically don’t make them very much in the fruit,” Martin told reporters in an interview. “They normally appear in the leaves and stems.”

So she started with, separating the DNA in the snapdragon flower that turns on and off the purple color. Next, she used a basic technique that was figured out by scientists in the 1980s to introduce it into a certain bacteria so that the tomato could then take in the foreign genetic material and express this new gene.

The result? In a paper published in Nature, Martin found that the purple tomato had, per weight, as much anthocyanin as a blueberry or eggplant, and that the mice who ate a diet mixed with purple tomatoes lived 30% longer than those who didn’t.

“Americans eat more tomatoes annually, so it makes the nutritional benefits more accessible,” Martin said.

Of course, some people have raised health concerns about eating genetically engineered foods. But these foods were introduced three decades ago and studies have not shown any harm.

“The purple potato is another great example of how the outcomes and applications of such biotechnologies can improve our life,” Martin said.

【推荐3】Last fall, the Great Salt Lake hit its lowest level since record keeping began. The lake sank to nearly six meters below the long-term average. The lake’s shrinking threatens to upend the ecosystem, disturbing the migration and survival of 10 million birds, including ducks and geese.

Duck hunters aren’t the only ones worried about the Great Salt Lake. The decades-long decline in lake level is raising alarm bells for millions of people who live in the region. The low lake level and increasing salts in the lake water threaten to destroy economic mainstays like agriculture, tourism and mining. Exposed salts can also reduce air quality and so threaten public health.

Saline lakes (咸水湖) are terminal lakes. They have no rivers flowing out of them. As water disappears, salts are left behind. At the same time, the people who live in these deserts use freshwater for crops, homes and industry. Residents get water from streams and rivers into canals, pipelines or reservoirs before it reaches the lakes. And as the lakes shrink, the salt in water increases.

Lake Poopo, a highland lake in Bolivia that used to stretch 90 kilometers long and 32 kilometers wide, is now a salty mud flat. The Aral Sea shared by Kazakhstan and Uzbekistan, once the world’s fourth largest lake, has at times in recent decades shrunk to a tenth of its historic 68,000-square-kilometer surface area. Some saline lakes, like Nevada’s Winnemucca Lake, dried up so long ago — the waters that fed it were led to agricultural fields — that most people have forgotten they were ever wet.

The good news is that people still have time to halt the Great Salt Lake’s decline by using less water. Cutting agricultural and other outdoor water use by a third to half through a combination of voluntary conservation measures and policy changes would allow the lake to refill enough to support the region’s economy, ecology and quality of life. If this succeeds, the Great Salt Lake can be a model for how to save other saline lakes around the world.