When it comes to keeping off extra pounds, watching what we eat may not be enough—we have to keep an eye on our food’s packaging, too. Half the world is expected to be overweight by 2035. In addition to overeating and lack of exercise, the scientific community is exploring another factor that may contribute—eating products packaged in plastic.

For a study published last year, researchers at the Norwegian University of Science and Technology set out to determine what chemical compounds (化合物) exist in 34 common plastic items that touch things we eat, such as yogurt cups, juice bottles, candy packages, and plastic wrap used for produce and cheese, as well as items often found in kitchen.

Of the 55,000 chemicals the researchers found in these items, only 629 were identifiable, which influence our bodies’ ability to regulate weight, troubling health effects. “We’re quite certain that there are many chemicals in plastic products that impact metabolism (新陈代谢), but we just couldn’t identify all of them,” Martin Wagner, a study co-author said. Strikingly, Wagner and his colleagues found that a third of all the common products they tested contain chemicals that cause the adipogenic (生脂的) process. Although we are exposed to them daily, most of these mystery chemicals are unknown, unstudied and unregulated.

For years, experts have been warning against plastic food containers, particularly for hot or oily foods which may make the plastics unstable and increase the risk of chemical leaching (渗出). As one of them, Wagner argues that we need to start reducing our exposure to plastic without waiting for more slow-moving research to prove that the plastics in our food, products, blood and organs are risk factors for bad health outcomes.

Really, reducing our plastic exposure should be our overall goal. When we think about cutting junk out of our diets, the criminals shouldn’t just be candy and soda—plastic needs to go, too.

Elephants are the only living land animals to have a long, boneless trunk, says Andrew Schulz,a mechanical engineer. Up until now, detailed knowledge of what happens inside that trunk during feeding has been extremely lacking. So Schulz and his colleagues worked with zookeepers at Zoo Atlanta to study it.

The study finds that an elephant’s trunk can suck up three liters of water in a second, a surprising rate of flow equal to about 24 shower heads, reports Katherine J. Wu for The Atlantic. Moving that much water so quickly requires inhaling (吸入) air at 330 miles per hour. That's 30 times faster than a human sneeze.

To do research on the trunk, researchers took high-speed video of a then 34-year-old African elephant named Kelly at Zoo Atlanta and assessed her long nose's suction capabilities (自吸能力).

In another experiment, the team measured the internal volume of a similar-sized, 38-year-old African elephant’s trunk. They found Kelly s impressive inhalation exceeded (超过) the volume of water they expected. To investigate further, the team used ultrasound to see what was happening inside an elephant’s trunk while it was sucking up water. This revealed that the trunk actually expanded its total volume by up to 64 percent.

Another test shows elephants’ ability to decide how to their trunk depends on what they’re trying to achieve. “An elephant’s trunk is useful in just about any situation. It’s like a multitool, ” Schulz says. “So an elephant's trunk is actually like a trunk. ” This research shows how effectively the trunk allows the elephant to move both air and water to help hold different objects.

According to The Atlantic, Schulz’s next move is to try to create a complete map of the internal structure of an elephant’s trunk in hopes of revealing more of the mechanisms (机制) behind its many uses.

Mummy's boys are less likely to suffer from poor mental health or unpopularity at school, research suggests. 【小题1】 They enjoy a similar lift in their self-esteem and confidence.

The study by the Marriage Foundation concluded that boys and girls who are close to their parent of the opposite sex do better at dealing with teenage life. Boys who are “extremely close" to their mothers at 14 are 41 percent less likely to have mental health problems, the research found. 【小题2】 While boys are happier when their parents are married, girls are more reassured by their parents having a high-quality relationship.

The analysis uses Millennium Cohort Study data from 11,000 mothers. 【小题3】Harry Benson, research director of Marriage Foundation who co-authored the study with Professor Steve McKay from the University of Lincoln, said： "Our analysis shows once again that family breakdown remains the number one driver of teenage mental health problems. 【小题4】 Boys who are close to their mum tend to have better mental health, as do girls who are close to their dad.”

Sir Paul Coleridge, chairman of Marriage Foundation, said： "Mummy's boys and daddy's girls have been known about for generations as something of a joke. 【小题5】Girls and boys, as they develop, do indeed have different emotional needs and expectations and do best when these needs are satisfied. A strong relationship with the parent of the opposite sex boosts self-esteem and peer group relationship skills-both of which support sound mental health. ”