I first came across the concept of pay-what-you-can cafes last summer in Boone, N.C., where I ate at F.A.R.M (Feed All Regardless of Means) Café. You can volunteer to earn your meal, pay the suggested price($10) or less, or you can overpay—paying it forward for a future customer's meal. My only regret after eating there was not having a chance to give my time. So as soon as Healthy World Café opened in York in April, I signed up for a volunteer shift(轮班).

    F.A.R.M and Healthy World are part of a growing trend of community cafés. In 2003, Denise Cerreta opened the first in Salt Lake City. Cerreta now runs the One World Everybody Eats Foundation, helping others copy her pay-what-you can model.

    “I think the community café is truly a hand up, not a handout,” Cerreta said. She acknowledged that soup kitchens(施粥所) have a place in society, but people typically don't feel good about going there.

    “One of the values of the community café is that we have another approach,” she said. “Everyone eats here, no one needs to know whether you volunteered, overpaid or underpaid.”

    The successful cafés not only address hunger and food insecurity but also become necessary parts of their neighborhood – whether it's a place to learn skills or hear live music. Some teach cooking to seniors; some offer free used books. Eating or working there is a reminder that we are all in this world together.

    My 10 am—1pm shift at World-Healthy-Café began with the café manager — one of the two paid staff members. Our volunteer crew wasn't the most orderly, but we managed to prepare and serve meals with a lot of laughs in between. At the end of my shift, I ordered my earned meal at the counter, together with other volunteers. After lunch, I walked out the door, with a handful of new friends, music in my head and a satisfied belly and heart.

    How old are the apps on your smartphone? Is it time for an update? Here are three apps for you. Try them out and have fun.

Duolingo

    Learning a foreign language doesn't always mean you have to sit in a class and take endless exams. An app called Duolingo has been designed to help you memorize (记住) new words and grammar in creative ways，such as online lessons，games and interesting exercises. For example，one exercise asks you to put words in the right order to make the correct sentence. You can also try translation practice.

Douban FM

    A music app is a necessity for almost every smartphone now. Douban FM might be the right thing for you.

    There is no playlist on Douban FM--songs just keep streaming (播放) one by one. You can use the “heart”, “trash” and “skip” buttons (按钮) to mark the songs you like，don't like and want to cut short, respectively (分别地). Those marked with a heart will be stored in another list as your favorites for you to listen to anytime you want. Douban FM also has different channels (频道). There are many types of music, such as blues, jazz, and pop. You can choose the music for outdoor activities, work or studying depending on your mood (心情).

Flipboard

    It is one of the hottest news apps right now. With Flipboard, you can make everything personal to you. All you have to do is open up the app, “flip through” to select whatever interests you，and click the “+” button. At the end you'll have your own magazine, complete with a front page, new articles, and information.

    Studies show that you may be lied to every day anywhere from 10 to 200 times. We say, “Nice song.” “Honey, you don't look fat in that, no.” But another study showed that strangers lied three times within the first 10 minutes of meeting each other. We lie more to strangers than we lie to coworkers. Men lie eight times more about themselves than they do about other people. Women lie more to protect other people. If you're married, you're going to lie to your wife/ husband in one out of every 10 communications. If you're unmarried, that number drops to three. But look, if at some point you got lied to, it's because you agreed to get lied to. Truth about lying: lying's a cooperative act. Not all lies are harmful. Sometimes we're willing to get lied to for social dignity(尊严), maybe to keep a private secret.

    Lying is complex. It exists in our daily and business lives. We're deeply disturbed by the truth. We explain it, sometimes for very good reasons, other times just because we don't understand the gaps between ideals and realities in our lives. We're against lying, but secretly we're for it in ways that our society has practiced for centuries and centuries. It's as old as breathing. It's part of our culture and history. Think the stories from Dante, Shakespeare, the Bible, News of the World.

    Lying has great value to the evolution of human beings. Researchers have long known that the more intelligent the species, the more likely it is to lie. We humans like to become leaders. It starts really early. How early? Well, babies will pretend to cry, pause, wait to see who's coming and then go right back to crying. One-year-olds learn hiding truth. Five-year-olds lie outright and try to control through flattery (奉承). Nine-year-olds, masters of covering up.

    So what do we do about lies? Well, there are steps we can take to guide our way through the bushes. Trained lie spotters (检测员) get to the truth 90% of the time. The rest of us, we're only 54% right. There are clever liars and stupid liars, but there're no real creative liars. While lying, we all make the same mistakes, and we all use the same techniques.

    Would it surprise you to learn that, like animals, trees communicate with each other and pass on their wealth to the next generation?

    UBC Professor Simard explains how trees are much more complex than most of us ever imagined. Although Charles Darwin thought that trees are competing for survival of the fittest, Simard shows just how wrong he was. In fact, the opposite is true: trees survive through their co-operation and support, passing around necessary nutrition（营养）“depending on who needs it”.

    Nitrogen（氮）and carbon are shared through miles of underground fungi（真菌）networks, making sure that all trees in the forest ecological system give and receive just the right amount to keep them all healthy. This hidden system works in a very similar way to the networks of neurons（神经元）in our brains, and when one tree is destroyed, it affects all.

    Simard talks about “mother trees”, usually the largest and oldest plants on which all other trees depend. She explains how dying trees pass on the wealth to the next generation, transporting important minerals to young trees so they may continue to grow. When humans cut down “mother trees” with no awareness of these highly complex “tree societies” or the networks on which they feed, we are reducing the chances of survival for the entire forest.

    “We didn't take any notice of it” Simard says sadly. “Dying trees move nutrition into the young trees before dying, but we never give them chance.” If we could put across the message to the forestry industry, we could make a huge difference towards our environmental protection efforts for the future.

    Now women are free to enter any career that attracts them, and working can bring them pride, confidence and independence. Working women make up nearly half of the U.S. workforce, and 51 percent of professional workers, like doctors, lawyers, nurses and accountants, are female. While climbing the career ladder can be rewarding, it often comes with one big disadvantage: weight gain!

    New research published this week in the International Journal of Obesity shows that working women are more likely to be overweight, and the more you work, the more pounds you're likely to pile on. Like many women, I work... a lot! As a self-employed nutrition communications specialist, I sit at my desk, in front of a computer, for hours on end. Sitting alone is one of the worst things you can do for your health, and it's directly linked to being overweight and increased fatness, so the fact that women in the workforce gain weight isn't that surprising. If you work, you have less time to move around. Obesity researchers are revealing many other ways that employment is harmful to your diet and waistline(腰围).

    In the International Journal of Obesity study, some 9,276 Australian women aged 45-50 had their body weight and employment status monitored for two years. Results? Those who worked more than 35 hours were likely to gain weight compared to those who worked fewer hours or were out of the workforce. What's more, the more hours a woman worked in a week, the more weight she gained.

    The authors of the Australian study attribute weight gain among working women to inactivity, lack of time for food preparation, more use of prepared foods, high levels of stress, lack of sleep and consuming more alcohol. I'll also add in travel, meals eaten out and working at night as other factors that I can find to make balancing work with a healthy diet a challenge.

A key part of protecting endangered species is figuring out where they're living. Using environmental DNA, or eDNA, to track species isn't new. For a few years now, researchers have been using DNA in water.

Two teams of scientists — one in Denmark led by Dr Kristine Bohmann and one in the UK led by Dr Elizabeth Clare — came up with the same question at about the same time: Could they identify the animals in an area from DNA that was simply floating in the air? DNA in the air is usually so small that it would take a microscope to see it. "I thought the chances of collecting animal DNA from air would be slim though much time had been spent on it, but we moved on," said Bohmann who was trying to think of a crazy research idea for a Danish foundation that funds far-out science.

One team collected samples from different locations at Denmark's Copenhagen Zoo, and the other at Hamerton Zoo Park in the UK. Clearly, they both chose the zoos. "We realized we have the Copenhagen Zoo," Bohmann recalls. In fact, both the zoos in the UK and Denmark were almost like the zoos that were custom-built for the experiments: The animals in the zoos were non-native, so they really stuck out in DNA analyses. "If we detect a flamingo (火烈鸟), we're sure it's not coming from anywhere else but the zoo," Bohmann says.

In the laboratory, by comparing their samples with examples of DNA from different animals, the scientists succeeded in identifying many different animals at the zoos.

Neither team knew that the other team was working on a similar experiment. The two were nearing submission to a scientific journal when they discovered about the other experiment. Rather than compete to rush out a publication first, they got in touch and decided to publish their findings as a pair. "We both thought the papers are stronger together," says Clare.

"The next step is to figure out how to take this method into nature to track animals that are hard to spot, including endangered animals," says Bohmann.