【推荐3】Vaping can be just as damaging to your health as smoking. But the minute you kick the habit, you’ll feel a difference.

Vaping is the use of electronic cigarettes — e-cigarettes. Vaping became mainstream in the United States in the late 2000s. When e-cigarettes first hit the market, people believed they were a safer choice to tobacco cigarettes. We now know, however, that vaping, like smoking cigarettes can be quite damaging to your health and equally addictive.

Kids and teenagers are especially attracted to vaping, thanks to attractive flavors. Vape use in high school students rose by 900 percent between 2011 and 2015. Quitting vaping can be difficult, just like trying to stop smoking. There are some immediate, though often temporary, negative effects. The positive ones soon outpace the negative, however.

In as little as 20 minutes, your heart rate returns to normal, your blood pressure drops, and your circulation starts to normalize. Your breathing may improve, too. Daily e-cigarette doubles a persons risk for a heart attack. If you quit, however, the risk begins to fall very quickly. Also, vaping, like cigarette smoking, can blunt your senses, reducing your ability to smell and taste. After just 48 hours without vaping, you may begin to notice your ability to taste and smell food has improved. Nicotine affects more than your brain: new research suggests nicotine can raise your blood sugar, too.

Smokers often have a troublesome cough or make a breathless sound when they breathe that many refer to as a smokers cough. Smoking even e-cigarettes can badly harm your lung health and make fighting off infections difficult. Quitting, however, will help your lungs recover. After one month, your lung capacity improves. There will come a day when the bad habit of vaping won’t have any lasting influence on your body and your health.

【推荐1】Learning a second language is tricky at any age and it only gets tougher the longer you wait to open that dusty French book. Now, in a new study, scientists have pinpointed the exact age at which your chances of reaching fluency in a second language seem to plummet: 10.

The study, published in the journal Cognition, found that it’s “nearly impossible” for language learners to reach native-level fluency if they start learning a second tongue after 10. But that doesn’t seem to be because language skills go downhill. “It turns out you're still learning fast. It’s just that you run out of time, because your ability to learn starts dropping at around 17 or 18 years old ,” says study co-author Joshua Hartshorne, an assistant professor of psychology at Boston College.

Kids may also be better than adults at learning new languages for many reasons. Children’s brains are more plastic than those of adults, meaning they’re better able to adapt and respond to new information. “All learning involves the brain changing,” Hartshorne says, “and children’s brains seem to be a lot more skilled at changing.”

Kids may also be more willing to try new things (and to potentially look foolish in the process) than adults are. Their comparatively new grasp on their native tongue may also be advantageous. Unlike adults , who tend to default to the rules and patterns of their first language , kids may be able to approach a new one with a blank slate.

These findings may seem discouraging, but it was heartening for scientists to learn that the critical period for fluent language acquisition might be longer than they previously thought. Some scientists believed that the brief window closes shortly after birth, while others stretched it only to early adolescence. compared to those estimates, 17 or 18—when language learning ability starts to drop off— seems relatively old.

“People fared better when they learned by immersion, rather than simply in a classroom. And moving to a place where your desired language is spoken is the best way to learn as an adult. If that’s not an option, you can mimic an immersive environment by finding ways to have conversations with native speakers in their own communities,” Hartshorne says. By doing so, it’s possible to become conversationally proficient—even without the advantage of a child’s brain.

【推荐3】Most of Earth's freshwater sits underground. Worldwide, about 70 percent of the groundwater drawn to the surface goes for farming. But surface waters-rivers and streams come from groundwater, too. Drawing too much groundwater over a short time can be harmful. Natural waterways can begin to empty. And that car hurt freshwater ecosystems. Scientists consider this a tipping point when small actions can begin making unusually big differences.

A new study has found that 15 to 21 percent of tapped water(自来水)areas have reached this sort of tipping point. Most of those tapped rivers and streams are in dry areas. Farmers in rates these areas use groundwater to water their crops. At present drawing rates, the study predicts that 42 to 79 percent of water areas around the world where groundwater is drawn up for use at the surface will reach tipping points by 2050.

A healthy groundwater aquifer(含水层)protects ecosystems against seasonal ups and downs in the use of water. That provides stability for area plants and animals. But if too much groundwater is drawn up from below, surface waters will begin to flow into the aquifer, which can harm what are living in rivers and streams.

De Graaf and the study team set up a computer model. It linked groundwater drawing and water flows within rivers. The model covered fifty years, from 1950 to 2010. Then the researchers used climate forecasts to help the model predict what might happen in future years. Throughout, they kept groundwater drawing rates sustainable. More than half of drawn water areas are likely to cross this ecological tipping point before 2050, the model finds.

"We need to be thinking about this now, not in 10 years," De Graaf says. "Our study shows us where to target more sustainable efforts."