【推荐1】Have you ever spent an afternoon in the backyard, maybe grilling or enjoying a basketball game, when suddenly you notice that everything goes quiet? There is an old phrase “calm before the storm”, often used in a situation---a quiet period just before a great activity or excitement. According to our own experience, we know there is actually calm before the storm. But what causes this calm? And is it always calm before the storm?

A period of calm happens in a particular kind of storm, the simplest kind of storm---a single-cell thunderstorm. In this type of thunderstorm, there is usually only one main stream of current, which is warm, damp air and drawn from places near the ground. Storms need warm and damp air as fuel, so they typically draw that air in from surrounding environment. Storms can draw in the air that fit their need from all directions—even from the direction in which the storm is traveling.

As the warm, damp air is pulled into a storm system, it leaves a low-pressure vacuum(真空) coming after. The rising air meets the cold dry air that has already existed in the storm clouds, thus the temperature of the warm, damp air drops, and the water vapor in it changes into tiny drops that are a precondition of rain. These drops accumulate and build on larger particles(颗粒) like dust, until they grow large enough to form raindrops.

This warm, damp air keeps moving upwards, but it becomes cooler and drier during its trip through cloud. When it reaches the top of the cloud, the air is squeezed out at the top. This air is sent rolling out over the big thunderclouds. From there, the air goes down. Warm and dry air is relatively stable, and once it covers a region, that air, in turn, causes the calm before a storm.

Most thunderstorms, though, don't start with calm. That's because most are actually groups of storms with complex wind patterns. There's so much air moving up and down storm groups that the calm before the storm never happens. Instead, before the storm, it might be really windy!

【推荐3】One of our biggest fears nowadays is that our kids might someday get lost in a “sea of technology” rather than experiencing the natural world. Fear-producing TV and computer games are leading to a serious disconnect between kids and the great outdoors, which will change the wild places of the world, its creatures and human health for the worse, unless adults get working on child’s play.

Each of us has a place in nature we go sometimes, even if it was torn down. We cannot be the last generation to have that place. At this rate, kids who miss the sense of wonder outdoors will not grow up to be protectors of natural landscapes. “If the decline in parks use continues across North America, who will defend parks against encroachment (蚕食)?” asks Richard Louv, author of Last Child in the Woods.

Without having a nature experience, kids, can turn out just fine, but they are missing out a huge enrichment of their lives. That applies to everything from their physical health and mental health, to stress levels, creativity and cognitive (认知的) skills. Experts predict modern kids will have poorer health than their parents — and they say a lack of outside play is surely part of it; research suggests that kids do better academically in schools with a nature component and that play in nature fosters (培养) leadership by the smartest, not by the toughest. Even a tiny outdoor experience can create wonder in a child. The three-year-old turning over his first rock realizes he is not alone in the world. A clump of trees on the roadside can be the whole universe in his eyes. We really need to value that more.

Kids are not responsible. They are over-protected and frightened. It is dangerous out there from time to time, but repetitive stress from computers is replacing breaking an arm as a childhood rite (仪式) of passage.

Everyone, from developers, to schools and outdoor citizens, should help regain for our kids some of the freedom and joy of exploring, taking friendship in fields and woods that cement love, respect and need for landscape. As parents, we should devote some of our energies to taking our kids into nature. This could yet be our greatest cause.

【推荐1】Learning is so complex that there are many different psychological theories to explain how people learn. A psychologist named Albert Bandura suggested a social learning theory which shows that observation, imitation (模仿), and modeling play a primary role in this process.

In Albert Bandura’s opinion, people can learn through observation. Observational learning doesn’t even necessarily require watching another person join in an activity. We can also learn by reading, hearing, or watching the actions of characters in books and films. However, just observing someone else’s actions isn’t always enough to lead to learning. Your own mental state also plays an important role in determining whether a behavior is learned or not. In addition, though in many cases, learning can be seen immediately when the new behavior is displayed, yet sometimes we can learn things even though that learning might not be immediately obvious, which means people can learn new information without showing new behaviors.

Not all observed behaviors are effectively learned. Certain requirements need to be related to the observational learning process. For example, you need to be paying attention. Also your retention is an important part of observational learning as you need to pull up information later and act on it during the process. Once you’ve paid attention to the model and kept the information, it’s time to actually perform the behavior you observed. Further practice of the learned behavior leads to improvement. Finally, you have to be motivated to imitate the behavior that has been modeled.

Social learning theory have many real-world applications. For example, researchers employ it to look into and understand ways that positive role models can be used to encourage desirable behaviors. Besides, it’s also applied in the field of education, and today, both teachers and parents recognize how important it is to model appropriate behaviors.

【推荐2】How Plants Branch Out to Access Water

New research has discovered how plant roots sense the availability of water in soil and then adapt (适应)their shape to acquire water. The discovery could enable crops to be raised which are more adaptive to changes in climate conditions, such as the absence of water, and help ensure food safety in the future.

These findings, published in the journal Science, describe a new mechanism(机制) discovered by cooperating teams at the universities of Nottingham and Durham.

Roots are very important for plants to acquire water and nutrients(营养)from the soil. Water is necessary to plant growth , yet changing climatic conditions makes acquiring water from soil even more challenging. Plants are able to adapt to different soil moisture(湿润)conditions by changing their roots.

The researchers discovered that plant roots lacking a branching master gene were no longer able to branch out. They found that when roots have access to moisture, the certain gene remains active and promotes root branching, but when put in air, the gene is in activated, preventing root branching. The research has identified the certain protein which can inactivate root branching.

Professor Sadanandom explained: "This is hugely exciting as it opens up the possibility for us to help develop plants that could continue to branch roots even in challenging conditions such as the absence of water.''

Professor Bennett concluded: "Water is the key to plant growth, development and their survival. By studying how plant roots change their branching in response(回应)to water availability, we have uncovered a new mechanism. This opens the way to develop new crops better adapted to climate change and to help deliver global food safety."

It is absolutely imperative to ensure food safety worldwide. Crop production must double by 2050 to keep pace with global population growth. This target is even more challenging considering the effect of climate change on water availability. In this case, developing crops with better ability to acquire water would provide a solution.

【推荐3】A person, like a commodity, needs packaging. But going too far is absolutely undesirable. A little exaggeration, however, does no harm when it shows the person’s unique qualities to their advantages. To show personal attractiveness in a casual and natural way, it is important for one to have a clear knowledge of oneself. A skilled packager knows how to add art to nature without any signs of embellishment, so that the person so packaged is not a commodity but a human being, lively and lovely.

A young person, especially a female, shining with beauty and full of life, has all the favor granted by God. Any attempt to make up would be self-defeating. Youth, however, comes and goes in a flash. Packaging for the middle-aged is primarily to hide the marks made by years. If you still enjoy life enough to keep self-confidence and work at pioneering work, you are unique in your natural qualities, and your attractiveness and grace will remain. Elderly people are beautiful if their river of life has been, through plains, mountains and jungles, running its course as it should. You have really lived your life, which now arrives at a self-satisfied stage of quietness and calmness with no interest in fame or wealth. There is no need to make use of hair dyeing. The snowcapped mountain itself is itself a beautiful scene of fairyland. Let your looks change from young to old in step with the natural ageing process so as to keep in harmony with nature, for harmony itself is beauty, while the other way round will only end in unpleasantness. To be in the company of the elderly is like reading a thick book of (better quality) edition, which attracts one so much that one is unwilling to part with it.

As long as one finds where one stands, one knows how to package oneself, just as a commodity sets up its brand by the right packaging.

【推荐1】Young sunflowers turn and swing every day. New findings add to evidence that the plants are animal-like.

Harmer, a professor in the University of California at Davis’ Department of Plant Biology, carried out a series of experiments on sunflowers in the field, in pots outdoors and in indoor growth chambers.

By staking plants so that they could not move, Harmer showed that he could destroy their ability to track the sun. He also noticed that sunflowers prevented from moving were not as tough and leafy as those that were free to move. When plants were moved indoor with a settled overhead light, they continued to swing back and forth for a few days.

The indoor plants did start tracking the “sun” again when the apparent source of lighting was moved across the room. The plants could reliably track the movement and return at night when the artificial day was close to a 24-hour cycle, but not when it was closer to 30 hours.

When sunflowers track the sun, the cast sides of their stems grew more rapidly than the west sides. Ai night, the west sides grew faster as the stem swung the other way. The team identified a number of genes that were expressed at higher levels on the sunward side of the plant during the day, or on the other side at night. A plant growth-regulating hormone, called auxin, appears to be a key driver.

The “dance” to the sun cycle obviously slows when the sunflower matures and its flowers open up. At that point, the plants stop moving during the day and settle down facing the sun in the east.

“Bees like warm flowers.” Harmer said, adding that the bees are cold-blooded, so landing on a warm flower saves them energy and perhaps feels really good.

“The morning warmth changes the flowers in a way to make them more appealing to insects, perhaps causing them to release more attractive scents earlier in the day.” he said. “We’re currently testing this idea.”

【推荐2】Teenagers who travel around the world alone have been making headlines quite often. A young person alone in a dangerous situation attracts attention and sponsors. Young sailors also attract various views. For example, Jessica Watson was asked by the government to cancel her voyage yet the Prime Minister called her "a hero for young Australians'' when she returned. It seemed there is confusion about the competence and independence of young people.

The popular psychologists tell us that teenage brains are likely to make wrong judgments. But such ideas often do not apply to specific individuals .Between the ages of 14 and 18, teenagers vary greatly in their abilities. The amount of independence that each is allowed should be determined not simply by their age but by discussion with the related, responsible adults. Some teens are certainly inexperienced and capable of childish mistakes, but the ones who attempt dangerous journeys normally do so by winning the confidence of hard-headed and well-qualified adult supporters.

But it’s also wrong to think that any 16-year old can desire to get achievements as unusual as Jessica Watson^’s. Watson calls herself "an ordinary girl who had a dream". Her intention is to encourage teenagers but this idea can have the opposite effect of making them feel not good enough because great achievements are beyond them. Should all teens have such dreams? Actually, individuals face varying circumstances that restrict their dreams.

Teenagers who travel around the world alone should not be judged by preconceived（事先形成的）views about young people. Nor should young ^“ordinary^” teenagers feel pressure to long for extraordinary personal goals. In fact, I believe the example of solo sailing overstresses individualism. The teenage years are when most of us "ordinary" people learn that we can achieve great things in cooperation with others.

【推荐3】When Liberia was my home, they called it sweet. Sweet was the word I remembered the most during the war. When I was five, my father, two sisters and I fled from Monrovia, the capital city of Liberia, and headed north on foot among panicked masses of criers - a journey that ended in a village where we hid from flying bullets (子弹). Every dawn, my sisters and I joined my father and covered the pages of his small journal with words. My favorite word to write was “sweet,” one that had the power to numb the reality of our 6-month abandonment by peace and civilization.

Eventually, we were considered the lucky ones: part of the wave of refugees who left Liberia in 1990 to settle in America. My mother studied at Columbia University at the time, and we made our new home in her dormitory while awaiting her graduation. My father who left early in the mornings looked for work or news of a possible return to Liberia, only to return home with nothing to give us but new words to write in notebooks. He quickly found that the education he received in Liberia was not good enough for an engineering job in the United States. So he took whatever job he could find to make sure we always had food on the table - and books.

In 2011, I founded a children’s book publishing company: One Moore Book. It provides children’s literature for the children of countries with low literacy (识字) rates and underrepresented cultures by publishing culturally relevant books that have something meaningful to say to them. My hope is to give children the peace I was given through the words of my father, by allowing them to see themselves in literature. I also think it is important to provide books about foreign countries to children in the United States, to increase the overall awareness of the world outside them.

I will never be able to give my father back the twenty years he spent working to educate us, or the home and life in Liberia he lost. I repay his sacrifice (牺牲) by honoring the education he fought for and offering my art to the world, with stories that make the histories of my people come alive, and with words to live by.