I'm part of the Roots & Shoots program founded by Dr. Jane Goodall. The program is intended to make and promote positive changes in the world. As Dr. Goodall says, "What you do makes a difference, and you have to decide what kind of difference you want to make."

    In Bulgaria, where I live, homeless dogs are everywhere. Many people here turn a blind eye to them. But I cannot ignore the life of a street dog whenever I see one wandering in the street, looking for something to eat. That's why I'm no longer a food waster. When I see wasted food, I always think of a hungry dog climbing to garbage bins, searching for food that people have thrown there. When eating in a restaurant, I'm not afraid to take leftover food to feed stray cats or dogs.

    A week ago, I saw a homeless dog around the garbage bins. Immediately I knelt down, spoke to her softly and ran my hands over her. I could see that she had had puppies. I couldn't imagine how she could have been able to care for them. Hours earlier, I'd bagged up a plate of leftover fish. As I unwrapped it, she wagged her tail and sniffed at it. She ate all the fish in no time.

    It's sad, isn't it? I can't understand why many of us waste so much and think little of it. These homeless animals have taught me that food is precious. Even when I don't have leftovers with me, I'll take the time to get something from the grocery store to feed them.

I know my power is small, so I hope that next time you see wasted food, do turn it into worthy food. You have the power to save a life!

    The more hours that young children spend in child care, the more likely they are to turn out aggressive and disobedient by the time they are in kindergarten, according to the largest study of child care and development ever conducted. Researchers said this correlation (相关性) held true regardless of whether the children came from rich or poor homes, were looked after by a relative or at a center, and whether they were girls or boys.

    What is uncertain, however, is whether the child care actually causes the problem or whether children likely to turn out aggressive happen to be those who spend more hours in child care. It also remains unclear whether reducing the amount of time in child care will reduce the risk that a child will turn into a mean person. What's more, quality child care is associated with increased skills in intellectual ability such as language and memory, leading some academics to suggest that child care turns out children who are “smart and naughty”.

    The government-sponsored research, which has tracked more than 1,300 children at 10 sites across the country since 1991, is bound to cause the debate over child care again: How should people balance work and family? And how should parents, especially mothers. Resolve the demands that are placed on them to be both breadwinners and supermoms?

    That debate was already on display at a news briefing yesterday, where researchers themselves had different opinions about the data and its implications (含义). “There is a constant relationship between time in care and problem behavior, especially those involving aggression and behavior,” said Jay Belsky of Birkbeck College in London, one of the lead investigators of the study who has previously annoyed women's groups because of his criticisms of child care. “On behalf of fathers or mothers?” interrupted Sarah Friedman, a developmental psychologist at the National Institute of Child Health and Human Development (NICHD) and one of the other lead scientists on the study. “On behalf of parents and families,” responded Belsky.

    “NICHD is not willing to get into policy recommendations.” said Friedman, contradicting her colleague. “There are other possibilities that can be entertained. Yes it is a quick solution—more hours in child care is associated with more problems. The easy solution is to cut the number of hours but that may have implications for the family that may not be beneficial for the development of the children in terms of economics.” In an interview after the briefing, Friedman said that asking parents to work fewer hours and spend more time with their children usually meant a loss of family income, which adversely(不利地) affects children.

    Scientists said that the study was highly reliable. But the researchers said they had no idea whether the behavioral difficulties persisted as the children moved to higher grades.

    Are you sick of going to bed late and waking up tired? Then grab your hiking boots and a tent. A new study suggests that camping in the great outdoors for a couple of days can reset your body clock and help you get more sleep.

    The body clock is an internal system that tells our bodies when it's time to go to sleep and when it's time to wake up. Scientists track this clock by measuring the amount of melatonin (褪黑激素) circulating in a person's blood at any given time.

    In a healthy sleeper, melatonin levels rise a few hours before bedtime, stay high through the night, and then settle back down when it's time to wake up.

    In our modern society, however, most of us stay up many hours past sunset and would probably sleep in many hours after sunrise if we could. And the trouble is, your melatonin levels may still be high when your alarm clock goes off in the morning, which leads to fatigue. It may also have other health consequences as well, such as diabetes (糖尿病), overweight and heart disease.

    Professor Kenneth Wright of the University of Colorado in the US wanted to see if our body clocks can be reset by a short stay in nature. His team recruited (招募) fourteen physically active volunteers in their 20s and 30s. Nine went on a weekend camping trip, while the other five stayed home. At the end of the weekend, the researchers reported that in just two days, the campers' body clocks had shifted so that their melatonin levels began to rise more than an hour earlier than they did before they left on the trip. By contrast, the body clocks of the group that stayed home shifted even later over the course of the weekend.

    “This tells us we can reset our clocks fast,” Wright said.

    Therefore, if you want to change your sleep patterns you could try to increase your exposure to natural light during the day and decrease the amount of artificial light you see at night. And if that doesn't work，there's always camping.

    In a time when ivory poaching（偷猎）has gotten so bad that it threatens to wipe out several animal species,a young Dutch designer is creating "egalitarian（平等主义）jewelry" made of our very own ivory—teeth.

    Lucie Majerus got the idea for her "human ivory" collection after having her wisdom teeth removed.She kept them and soon realized they would make great material for a jewelry collection."Why wouldn't we value our own material instead of the precious material from other species?And what if we mine our own ivory and turn it into pearls?"she asks.

    Her own teeth became a ring,but in order to create a whole collection,she needed more material,and since having more of her teeth removed wasn't a very pleasant choice,she asked her dentist to save his patient's unwanted teeth.Most people choose not to keep their pulled teeth,so they are usually donated to dentistry schools.Majerus also received the lost teeth of two of-her teachers at Design Academy Eindhoven,so she had a nice supply of human ivory to experiment with.

    To turn human teeth into attractive pieces of jewelry,Lucie Majerus first bleaches（漂白）them,and then uses a stone polishing machine to shape the teeth into various shapes.

    Majerus displayed her human ivory jewelry collection at this year's Dutch Design Week,and claims that people's reaction was mostly positive."Surprisingly,most people aren't frightened at the sight of the jewelry,but really like the idea,"Majerus told Fast Co Design."Some regret that they didn't keep their tooth at the dentist and some,who will have teeth taken out soon,are now looking forward to it."

    It is not only praise or punishment that determines a child's level of confidence. There are some other important ways we shape our kids—particularly by giving instructions and commands in a negative or positive choice of words. For example, we can say to a child "Don't run into traffic!" or "Stay on the footpath close to me." In using the latter, you will be helping your kids to think and act positively, and to feel competent in a wide range of situation, because they know what to do, and aren't scaring themselves about what not to do.

    Actually, it is all in the way the human mind works. What we think, we automatically rehearse. For example, if someone offered you a million dollars not to think of a blue monkey for two minutes, you wouldn't be able to do it. When a child is told "Don't fall off the tree," he will think of two things: "don't" and "fall off the tree". That is, he will automatically create the picture of falling off the tree in his mind. A child who is vividly imagining falling off the tree is much more likely to fall off. So it is far better to use "Hold on to the tree carefully."

    Clearly, positive instructions help kids to understand the right way to do things. Kids do not always know how to be safe, or how to react to the warning of the danger in negative words. So parents should make their commands positive. "Sam, hold on firm to the side of the boat" is much more useful than "Don't you dare to fall out of the boat?" or worse still "How do you think I'll feel if you drown?" The changes are small but difference is obvious.

    Children learn how to guide and organize themselves from the way we guide them with our words, so it pays to be positive.

When I was a kid, my mom liked to make breakfast food for dinner every now and then. And I remember one night in particular when she had made breakfast after a long, hard day at hospital.

On that evening so long ago, my mom placed a plate of eggs, sausage and extremely burned toast in front of my dad. I remember waiting to see if anyone noticed! Yet all my dad did was to reach for his toast, smile at my mom and ask me how my day was at school. I don't remember what I told him that night, but I do remember watching him spread butter and jelly on that toast and eat every bite!

When I got up from the table that evening, I remember bearing my mom apologize to my dad for burning the toast. And I'll never forget what he said: "Honey, I love burnt toast."

Later that night, I went to kiss daddy good night and I asked him if he really liked his toast burnt. He took me in his arms and said, "Your momma put in a hard day at work today and she's really tired. And besides, a little burnt toast never hurt anyone!"

You know, life is full of imperfect things and imperfect people. What I've learned over the years is that learning to accept each other's faults is one of the most important keys to creating a healthy, growing, and lasting relationship. This good quality is the base of any relationship—husband­wife or parent­child or friendship! As far as I'm concerned, I'm not the best engineer as expected. However, I have made my efforts. That's enough.

So learn to take the good, the bad, and the ugly parts of your life. Burnt toast isn't a deal­breaker! Don't put the key to your happiness in someone else's pocket but into your own. You will appreciate the value of every soul including yourself.