A team of engineers at Harvard University has been inspired by Nature to create the first robotic fly. The mechanical fly has become a platform for a series of new high-tech systems. Designed to do what a fly does naturally, the tiny machine is the size of a fat housefly. Its mini wings allow it to stay in the air and perform controlled flight tasks.

    “It's extremely important for us to think about this as a whole system and not just the sum of a bunch of individual components,” said Robert Wood, the Harvard engineering professor who has been working on the robotic fly project for over a decade. A few years ago, his team got the go-ahead to start piecing the components together. “The added difficulty with a project like this is that actually none of those components are off the shelf and so we have to develop them all on our own,” he said.

    They engineered a series of systems to start and drive the robotic fly. “The seemingly simple system which just moves the wings has a number of interdependencies on the individual components, each of which individually has to perform well, and then has to be matched well to everything it's connected to,” said Wood. The flight device was built into a set of power, computation, sensing and control systems. Wood says the success of the project proves that the flying robot with these tiny components can be built and manufactured.

    Wood says the design offers a new way to study flight mechanics and control at insect-scale. Yet, the power, sensing and computation technologies on board could have much broader applications. “You can start thinking about using them to answer open scientific questions, you know, to study biology in ways that would be difficult with the animals, but using these robots instead,” he said. “So there are a lot of technologies and open interesting scientific questions that are really what drives us on a day to day basis.”

    It is generally believed that humans can't live without sleep. As any person suffering from lack of sleep knows, dark circles under the eyes usually stand out after a bad night's sleep.

    But why do people get these dark eye bags? The answer is both genetic (that is, relating to your DNA) and environmental (a result of your everyday living, such as rubbing your eyes or getting too little sleep), said Dr. Carol Clinton, a skin-care researcher in Dublin, Ohio.

    But “the biggest reason is genes,” Clinton told Live Science. Eye bags are generally more noticeable in people who, because of genes, have thin or pale skin. When people are tired or very nervous, blood circulation in the eye area becomes slow, allowing blood to pool there, Clinton said. Capillaries（毛细血管）stand out, leading to dark eye circles, she said.

    Besides, eye bags result from eyes' fat moving forward. An age-connected increase in fat beneath the eyeballs leads to eye bags. “Anyway, when your eyes' fat is moving forward, you may think about having an operation in that area,” Clinton said, “A person can get 9 hours of sleep a night, but still have eye bags because of a genetic development.”

    In other cases, environmental problems cause eye bags. For example, allergies（过敏）—especially seasonal allergies—can cause capillaries to stand out. Getting too much sun can also damage and thin the skin, making dark circles under the eyes easy to see. Besides, eating salty foods can cause the body to hold more water, which makes eye bags worse, according to the Mayo Clinic.

The situation is that familiar — deadlines are approaching, time runs out, disorder and confusion fills the day. The feeling is just as familiar — a slightly faster heart rate, and shortness of breath. Yes, it is panic time.

    It's too late to kick yourself with "I should have started on this sooner." or "It was a mistake to accept this tight deadline." The only thing left to deal with the situation is to panic more efficiently.

    ① Focus.

Panic happens when you are on an overload — too many things to do, too much pressure, too little time. But if you focus on the tasks that you need to take care of, and line them up in a logical list, you can have better control of a highly stressful and wild situation.

    ② Get rid of distractions.

    Time wasters and unnecessary activities are the last things you need during this time. Let everyone know you are on panic mode and should not be disturbed unless it is an emergency.

    ③ Watch your time.

    Don't be too engaged in one detail so that you reduce your timing for the other important details. Mind the time and deal with each task so that you can finish all of the required activities sufficiently.

    Try to solve a panic situation as quickly as you can so that you can rest and get back your energy and strength for the next one.

    In this day and age, you can practically do anything with the help of the Internet. While chatting with a stranger may seem new and exciting, make sure that you stay safe while still having fun.

    While there are some unpleasant people in the world, let's remember that most people are friendly! If you find someone who likes the same restaurant as you or who is also crazy about Gilmore Girls, then feel free to talk the night away! Just keep the conversation light and talk about your common interests. If a topic that doesn't fit well with you is brought up, keep in mind that you are always in control. Under no circumstances should you be forced to talk or think about anything inappropriate. Ignore your manners at this time!

    Do stay open-minded. Sometimes chatting with strangers can turn into a close bond—or just another person you can turn to for a laugh. But when you are typing away in your computer, it's easy for you to get carried away and to tell your new friends all about yourself. Keep the personal details secret, and instead talk about fun hobbies or the latest episode (一集) of The Good Wife.

    Always listen to your instincts (直觉). If something inside of you is telling you something isn't right, it probably isn't. Pay attention to how your body responds to certain people online. Remember, you never really know who you are talking to just by looking at a computer screen name, so downloading anything is absolutely no.

    See? Talking to strangers online doesn't always have to be appalling experience. By following these do's and don'ts, chatting with someone you don't know can be cool and pleasant, and can make sure that you stay safe in the world of the Internet.

    Wolves travel shorter distances and move slower during snowfall events, according to new research by University of Alberta biologists. The effects were most pronounced at night, when wolves hunt, and behaviour returned to normal within a day. Wolf tracks across snow in northeastern Alberta.

    "Our findings suggest that there is something about actively falling snow that causes wolves to slow down," said Amanda Droghini, a former MSc student in the Department of Biological Science and lead author on the study. "We don't know the exact mechanism behind that. It's unlikely that they were staying still because they were feasting on a recent kill. Instead, active precipitation（降雪量）might affect wolves' hunting abilities. Like rain, snow clears the air column of scent molecules. So, maybe falling snow makes it harder for wolves to detect the smell of prey."

    Over the course of two winters, the researchers used remote cameras to disclose snowfall events and estimate snow depth. To study wolf movement, they collected telemetry（测距仪） data from 17 wolves to calculate travel speed and duration, as well as resting periods. It is the first study to examine how large flesh-eating animals respond to snowfall events.

    With the effects of climate change on precipitation in the north forest region uncertain, it is difficult to predict the implications for wolf populations. Studies such as these increase our understanding of how large mammals react to normal snowfall events, but the type and amount of winter precipitation will likely have an impact on animal behavior and the energetic cost of movement.

    "Winter is already challenging for many wildlife species because moving through snow requires more energy. Snow can also make it harder for animals to access food resources," said Droghini, who conducted the research under the supervision of Professor Stan Boutin, Alberta Biodiversity Conservation Chair.

    "Anything that increases those costs, such as increased rain-on-snow events, could lead to lacking in nutrition, poor body condition, and even starvation as animals are unable to make up for those additional costs. That is one of the worst-case scenarios（设想）but, in truth, we know very little about potential changes to precipitation patterns and how wildlife will respond to those changes."

    The extreme hot weather often makes people restless with sweats in summer. Even though people are annoyed by it, experts suggest that summer is the best season to give out your body's poisonous matters and refresh your energy.

    One popular choice is hot-stone massage(按摩). Therapists(理疗师)use smooth and heated stones, usually river rocks, to massage certain parts of the body, or set them on key points of the body. The warmth of the hot stones will promote blood circulation and also help muscles relax, while sweating is also believed to be good for letting out the body's poisonous factors.

    Another popular choice is hot-stone baths. The hot-stone bath will help the body give out poisons and humidity(湿气) that build up during the last winter. Summer is the best season to form a good body. Rather than use water or steam to heat and wash the body, people simply wear a coat or something comfortable, and then lie on heated stone tablets made of hot stones, which are warmed to around 45^oC. The body will gradually warm up and blood circulation will also be improved. More sweat will come out quickly. The sweat is smooth and fresh, not smelly like that released after sports activities. Such baths bring a number of health benefits, such as anti-aging, improved blood circulation and stress relief. The slimming effect of dieting can even be promoted.

    It dates back to ancient times to use hot stones for treatment, but the modern hot-stone massage generally owes to Mary Nelson, a native of Tucson, Arizona, America, whose trademark is "La Stone Therapy".

    The therapy is earning a good fame and popularity with many people, especially those who are often seated in cool rooms with air-conditioners. The hot-stone therapy can help cure many illnesses, back pain included.