Expensive perfumes (香水) come in tiny bottles, but many hide a whale-sized secret.

    To perfect a particular smell, perfume-makers often use an ingredient that comes from sperm whales, called ambergris (龙涎香). But using ambergris, which helps a perfume last longer, is strongly opposed by many people who think it is wrong to kill whales just so we can smell sweet. Joerg Bohlmann is neither a perfumer nor a whale expert. He's a plant biologist at the University of British Columbia in Canada. But his discovery of a new plant gene (基因) might push whales out of the perfume business.

    The gene comes from fir trees, found throughout North America and commonly used as Christmas trees. The trees produce a chemical that can be used in perfume in place of ambergris-but with a catch. "There's a problem that many people wouldn't consider. In the tree, the chemical is mixed with many others. That makes separation a challenge," Bohlmann says. "lt's like trying to isolate sugar from a biscuit. "

     This is where science becomes useful. When Bohlmann learned that fir trees produce the ambergris-like chemical, he decided to use his gene know-how to find the instructions for how to make the ambergris-substitute.

    Bohlmann found that gene and took it out of the tree cells. Then he did something that might sound strange to someone who doesn't work in genetics: Bohlmann put the gene from the tree into yeast (酵母) cells.

    Yeast may sound familiar because it's used to make things like bread, wine and beer. Biologists like to work with yeast because it easily adopts new genes and changes its features and behaviour. When Bohlmann put the fir tree gene into the yeast, the yeast started making the same chemical that had been produced by the tree.

    Perfumers pay big money for ambergris because it is a fixative, which means it holds a smell in place on a person's body.

    "Cheap perfumes smell good in the first hour or so and then everything is gone," explains Bohlmann. "But expensive perfumes are much more stable.  Their smell lasts much longer, for hours or even a day after you apply them. "

    The new chemical, made from the tree genes, can be used as a fixative, too. And using yeast to make it is far cheaper than acquiring ambergris.

    Bohlmann admits he never thought he'd get into the perfume business. But now, he says, producers have been calling to find out how to use his technology in new perfumes.

    For many parents, raising a teenager is like fighting a long war, but years go by without any clear winner. Like a border conflict between neighboring countries, the parent-teen war is about boundaries: Where is the line between what I control and what you do?

    Both sides want peace, but neither feels it has any power to stop the conflict. In part, this is because neither is willing to admit any responsibility for starting it. From the parents' point of view, the only cause of their fight is their adolescents' complete unreasonableness. And of course, the teens see it in exactly the same way, except oppositely. Both feel trapped.

In this article, I'll describe three no-win situations that commonly arise between teens and parents and then suggest some ways out of the trap. The first no-win situation is quarrels over unimportant things. Examples include the color of the teen's hair, the cleanliness of the bedroom, the preferred style of clothing, the child's failure to eat a good breakfast before school, or his tendency to sleep until noon on the weekends. Second, blaming. The goal of a blaming battle is to make the other admit that his bad attitude is the reason why everything goes wrong. Third, needing to be right. It doesn't matter what the topic is —politics, the laws of physics, or the proper way to break an egg—the point of these arguments is to prove that you are right and the other person is wrong, for both wish to be considered an authority—someone who actually knows something—and therefore to command respect. Unfortunately, as long as parents and teens continue to assume that they know more than the other, they'll continue to fight these battles forever and never make any real progress.

It's true to say that technology makes our lives easier. However, increasingly scientists are saying that we need to give ourselves a break—--otherwise we put ourselves at risk(风险) of developing hundreds of health problems. Over the summer the days are longer and sunnier. Why not put this free time to good use and do something away from technology?

    You could learn a new skill. There are hundreds of possibilities: cooking, a musical instrument or a new sport. Haven't you always wanted to learn how to knit(编织)? You could use your free time to practice these new things, which might lead to an exciting opportunity in the future.

    If you just want to relax, why not head to a beach? Take along your favorite book and relax on the sand, or go for a walk along the coastline. If you don't live near a beach, you could go to your local park. Why not have a picnic, or try to explore some of the local wildlife? You could even get involved in the latest craze(狂热): adult coloring books! Coloring is a surprising thing to help you relax, and it can be a nice way to escape from the stress of modern life!

    Whatever you choose to do, try something new! You might surprise yourself and find a hidden gift within you; you might make new friends along the way. Next time you find yourself changing TV channels(频道) from one to another without a clear purpose, think about what else you could spend your time doing.

    There is a story about a man who lost his legs and left arm in an accident. After the accident, only a finger and thumb on his right hand remained.

    He was a brilliant, creative, and educated man. He had gained a lot of experience while traveling around the world, so he became very depressed after his accident. He was afraid that he would spend the rest of his life suffering and would no longer be able to spend his life in a meaningful way. Then, he realized that he still had partial function of his right hand and could still write even though it was very difficult. An idea occurred to him. “Why not write to other people who need encouragement?”

    He wrote to the prison ministry about sending letters to the prisoners. The prison minister replied, “Writing to the prisoners is acceptable, but your letters will not be answered.”

    Filled with excitement, the man knew he could write his letters. He began sending one-way messages of God's love, hope, strength, and encouragement. He wrote twice a week, testing his strength and ability to the limit. He poured his heart and soul into his words and shared his experience, sense of humor, optimism, and faith.

    It was difficult to write those letters, especially without hope of a reply. One day he received a letter from the prison ministry. It was a short note from the officer who monitored and checked the prison mail.

    The letter said, “Please write on the best paper you can afford. Your letters are passed from cell (囚房) to cell until they literally (逐字地) fall to pieces!”

    No matter what circumstances life may present, we all have unique experiences, abilities, and God-given talents. We can discover ways to reach others who desperately need messages of encouragement and strength.

Muir Woods and Sausalito Half Day Tour

    Wander through an ancient coastal redwood forest and explore the artistic bayside on this half-day tour from San Francisco. Travel across the Golden Gate Bridge to visit Muir Woods, home to some of the oldest and tallest trees on Earth. At the end of your tour choose between getting dropped off at Union Square in San Francisco or taking the ferry back to San Francisco.

    Yosemite National Park and Giant Sequoias Day Trip

    Discover the beauty of the Sierra Nevada on this full-day trip to Yosemite National Park from San Francisco. Travel aboard a comfortable van through historic Gold Rush towns to reach the park, where you'll be amazed by supersized natural wonders. Take a hike among ancient trees, and enjoy several hours to explore the park's wonders on your own.

    Niagara Falls Tour

    Escape from New York City and head north to see both sides of the Canadian border on this guided, 2-day tour to Niagara Falls. Visit Niagara Falls on both the American and Canadian sides and take a ride on the famous Maid of the Mist boat. Then, on the road back to New York City, make a stop to shop at the Crossings Premium Outlets, one of the largest outlet malls in the US.

    Napa and Sonoma Wine Country Tour

    Escape to California's famous wine country on this full-day tour from San Francisco. Taste regional varietals at three different wineries including both big-name and family-run estates (庄园). Learn about the winemaking process during guided tours, and appreciate the regional culture with a stop for lunch.

Robots have long been drawing inspiration from animals, with the creation of robot dogs or snake-shaped robots. And yet, the field of robotics is far less enthusiastic about the other kind of living things—plants. Barbara Mazzolai, an Italian roboticist owes this to a misconception about plant behavior: that they cannot move or think. "It's not true at all, " she says. To challenge this view, Dr Mazzolai and her team recently launched a machine called "FiloBot", a robot based on a climbing species. 

To survive, a climbing plant must switch between several different behaviors. In forest environments, it must first grow out of the soil and travel along the ground in search of a support to hold onto, such as a nearby tree. Once a support is located, though, the plant fixes itself around the object and then growing towards the light. To choose the best angle to grow upwards, a climbing plant uses its shoots(芽) to receive information about light and gravity. 

FiloBot has sensors on its main shoot. It can 3D-print its body with plastic and grow at a controllable rate. These functions, researchers found, enabled FiloBot to cross gaps, and find things to attach to. The lack of heavy on-board computing device means that it is light and requires minimal care, while its slow pace means that it doesn't disturb things around it, making it possible to move through a complex, unseen environment, or monitoring disaster sites. 

For now, FiloBot is still being tested. Its tendrils(卷须) have not left the laboratory. Still, it has already been employed in deconstructing plant behaviour. For example, it was long assumed that climbing plants find their supports by growing towards shade, though the exact mechanism was unclear. FiloBot could imitate this behaviour by detecting far-red light, which is typical of shaded areas, providing clues to how plants do it. 

Dr Mazzolai hopes that such projects will inspire other roboticists to take their cues from plants and develop completely new technologies.