Today, we know that the role of vitamins and minerals goes way beyond the prevention of deficiency diseases (维生素缺乏症) to actually preventing cancer and heart disease, the most fearsome killers of our time. With this knowledge has come the widespread call for nutritional supplementation (营养补充) — and a confusing group of vitamin, mineral, and supplements lining the supermarket shelves.

    Far from contributing to better health, however, nutritional supplements threaten to turn a scientific breakthrough into a nutritional disaster.

    Promoters of vitamins and minerals — especially vitamins A, C, and E— would have consumers believe that the little vitamin pill in the bottle is all they need for good health. Take your vitamins in the morning, and you're covered. It's okay to eat fast foods for the rest of the day or skip meals to achieve today's fashionably skinny look. But vitamins and minerals are only one part of the nutritional puzzle. A diet rich in fiber (纤维) and balanced in carbohydrates and protein is essential for good health. You can't get these things from a nutritional supplement. The focus on vitamin and mineral supplements may actually be robbing us of the full nutrition we seek.

    And no supplement can compare to the quality of nutrition found in natural sources. For example, our bodies turn carotenes (胡萝卜素) from plant foods into vitamin A. Many supplements contain a single carotene, but natural sources are rich in many different carotenes. Many supplements contain a form of vitamin E that is made from chemicals, when natural vitamin E is more readily absorbed and used by the body. And science is still discovering the wealth of nutrients in foods.

    You'd be hard-pressed to find a supplement as nutritionally comprehensive and powerful as a balanced diet. Even if you could, you'd pay much more than if you got the same nutritional value from natural sources.

    But perhaps the greatest danger presented by nutritional supplements comes from the very real risks presented by self-medication. Anyone can walk into the market and buy as many different supplements as desired. The reported benefits of high dosages of certain nutrients have led some people to believe that the more the better. Many take several vitamin and mineral supplements without regard to possible consequences.

    Surprising new research suggests that vitamin C pills may speed up hardening of the arteries, the underlying cause of heart attacks. Researchers said their findings support the recommendations of health organizations, which urge people to avoid high doses of supplements and to get their nutrients from food instead.

    As appealing as they're made to sound, nutritional supplements are danger in disguise. If you're looking for good health, don't look on the supplement shelves of your supermarket. Look in the produce section instead.

    Although his 1-year-old smart-phone still works perfectly, Li Jijia already feels the need to replace it.

    “There are many better ones available now. It's time to upgrade(更新）my phone.”

    Li's impatience is shared by many. Shortly after the season when new products are released（发布，发售）, many consumers feel the urge to upgrade their electronic equipment, even though the ones they have still work just fine.

    As consumers' minds are occupied by Apple's newly released products and debate whether the Google tablet is better than the new Amazon Kindle, it might be time to take a step back and ask: “Do we really need the latest upgrades?”

    According to Donald Norman, an American author, “planned obsolescence (淘汰）” is the trick behind the upgrading culture of today's consumer electronics industry.

    Electronics producers strategically release new upgrades periodically, both for hardware and software, so that customers on every level feel the need to buy the newest version.

“This is an old-time trick—they're not inventing anything new,” Norman said. “This is a wasteful system through which companies--many of them producing personal electronics-- release poor-quality products simply because they know that, in six months or a year, they'll put out a new one.”

    But the new psychology of consumers is part of this system, as Norman admitted, “We now want something new, something pretty, the next shiny thing.” In its most recent year, Apple's profit margin(利润) was more than 21 percent. At Hewlett-Packard, the world's biggest PC maker, it was only 7 percent.

    Apple's annual upgrades of its products create sales of millions of units as owners of one year's MacBook or iPhone line up to buy the newest version, even when the changes are slight.

    As to Li Jijia, the need for upgrading his smart-phone comes mainly from friends and classmates. When they are switching to the latest equipment, he worries about feeling left out.

    “Some games require better hardware to run,” said Li. “If you don't join in, you lose part of the connection to your friends.”

    Wood has many great characteristics that make it the perfect building material. It is cheap, durable, easily available, and most importantly, environmentally sustainable. The one thing it is not, is transparent! Now thanks to a team of scientists at Stockholm's KTH Royal Institute of Technology the material may even be able to add that feature to its already impressive list.

    Lead researcher Dr, Lars Berglund said he was inspired to create the transparent wood after learning how Japanese researchers had developed a see-through paper for use in flexible display screens for electronic devices. The team began by pulling out the wood's lignin(木质素). The lignin-free wood was then dipped into a polymer(聚合物)and baked at a temperature of 158°F for four hours. The result was a hybrid product that was not only stronger and lighter than the original wood but also, almost transparent. The researchers were able to adjust the level of transparency by varying the amount of the polymer injected and also by changing the thickness of the wood.

    While scientists have previously created a see-through wood for small-scale applications like computer chips, the transparent wood is the first one being considered for large scale applications. The researchers, who revealed their findings in Biomacromolecules on April 11, picture using the transparent wood in buildings to allow for more natural light, or to create windows that let in the desired amount of light without sacrificing privacy.

    Wood that allows light to pass through could lead to a brighter future for homes and buildings. Berglund also thinks the wood could play a significant role in the design of solar panels. The semitransparent material would be able to keep light longer and give it more time to interact with the conductor, thus resulting in better solar efficiency. Additionally, substituting the currently used glass with this new product would help solar energy manufacturers improve their carbon footprint and lower the cost. They are now experimenting with ways to scale up the manufacturing process so that the transparent material is cost-effective to make and easy to use.

    Traditionally, robots have been hard, made of metal and other rigid material. But a team of scientists at Harvard University in the US has managed to build an entirely soft robot-one that draws inspiration from an octopus (章鱼).

    Described in science journal Nature, the "Octobot" could pave the way for more effective autonomous robots that could be used in search，rescue and exploration. "The Octobot is minimal system which may serve as a foundation for a new generation of completely soft, autonomous robots" the study's authors wrote.

Robots built for precise, repetitive movements in a controlled environment don't do so well on rough terrains (地形) or in unpredictable conditions. And they aren't especially safe around humans, because they're made out of hard and heavy parts that could be potentially dangerous to their users.

    So researchers have been working on building soft robots for decades. They're taken inspiration from nature, looking to animals from jellyfish to cockroaches, which are often made up of more flexible matter.

    But creating a completely soft robot remains a challenge. Even if engineers build a silicone (硅酮) body, it's still a grand challenge to construct flexible versions of essential parts, such as a source of power.

    "Although soft robotics is still in its early stage, it holds great promise for several applications, such as search-rescue operations and exploration," Barbara Mazzolai and Virgilio Mattoli of the Italian Institute of Technology' Center for Micro-BioRobotics, wrote in a comment. "Soft robots might also open up new approaches to improving wellness and quality of life."

    While most people have the idea that volcano eruptions are one of the most destructive disasters in nature, seeing a volcano erupt is a wonderful experience, and you can really feel the heat by climbing to the summit of Pacaya for a close-up view.

    There are guided tours every day up this highly active volcano from Antigua, giving travelers a chance to see Mother Nature at her most powerful. Pacaya is an easy drive from Antigua, a beautiful city with many colorful houses along its old streets that are turned into art-works during its Holy Week festival. No matter when you come to Antigua, you won't miss the Pacaya-tour companies.

    But climbing Pacaya is no easy job: it is 2,560 meters high, and reaching the summit takes two to three hours of seemingly one-step-forward and two-step-back movements. As you climb you hear the dull sounds of eruptions high above. Steaming, hot remains from recent eruptions begin to line the path as you near the active summit: the Mckenney Cone (火山锥). Just as though you were going to walk over to the edge of the cone, the road turns to the left and up to the relative safety of the old, inactive summit.

    Many tours are timed so that you arrive at the cone of the volcano in plenty of time for sunset and the full contrast between the erupting red lava(岩浆) and the darkening sky. On a good day the view from the summit is extremely exciting. The active mouth boils, sending red lava over its sides, and once in a while shoots hot steams up to 100 meters into the air. There is a strong bad smell in the air even if you take care to be upwind of the cone. As evening turns deeper into the night, the burning lava quietly falls down the side of the volcano. For you, too, it is time to get down.

    Procter & Gamble (P&G), one of the world's biggest marketers, has announced a change in the way it buys advertising on Facebook. It has started cutting its spend on highly targeted ads and increasing its spend on ads that address much larger numbers of the potential audiences for its brands, which include Tide, Pampers and Gillette. Explaining this change of emphasis, P&G's global brand building officer, Marc Pritchard, said, "We targeted too much, and went too narrow."

    Facebook's astonishing income growth comes, in part, from its ability to deliver micro-targeted audiences (推送精准目标受众) to advertisers, and P&G in fact admits that it has wasted millions of dollars in the misguided pursuit of effectiveness.

    Facebook used to be irresistible to advertisers. It presents advertisers this question: Instead of sending your message to millions in a television ad, why not use data to reach only those you need to reach? But as many people may have noticed, making perfectly targeted ads appears to be much harder than it sounds. Most digital ads are easily ignored. Information about consumers is not the same as insight into human beings.

    The more fundamental problem with micro-targeting is that for big brands, advertising has never really been about messages—even brand owners have never quite realized it. It is about the creation of shared memories, triggered at the point of purchase. Think about some of the great brands: Nike, Apple, and yes, Pampers. If you buy them, it is because you know millions of others do, and because they seem to stand for something that, far from being unique to you, is common to all of us: achievement, creativity, and nurturing. The broader these brands go, the better they do.

    When a consumer reaches for something on the shelf, they usually reach for the familiar. To achieve that status, a brand needs to have done something that lots of people regularly see, notice and enjoy. What seemed to be the wastefulness of TV was in fact its secret sauce. By reaching large numbers of people at the same time, TV ads had the power to turn brands into cultural icons, which took up consumers' minds.

    In its conversations with advertisers, Facebook now talks less about targeting, preferring to emphasize the large number of consumers that it can help brands to reach. It is investing in video functions and is encouraging its clients to make short films. After years of telling clients TV is wasteful, it is now doing a good job of imitating it.