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 integrated 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 (元件),” 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 together the components.“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, but 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.

    While this first robotic flyer is linked to a small, off-board power source, the goal is eventually to equip it with a built-in power source, so that it might someday perform data-gathering work at rescue sites, in farmers' fields or on the battlefield. “Basically it should be able to take off, land and fly around,” he said.

    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.”

    Have you been told you have penicillin allergy? Did your parents tell you that you had a reaction as an infant or child, so you should never take it again? Has it been so long since you had a reaction to penicillin that you don't remember what happened? If you fit any of these descriptions or are just not sure if you have penicillin allergy, there's good news for you: Chances are, you probably don't have it.

    Between 10 to 20 percent of Americans believe they have a penicillin allergy, but a recent study at Mayo Clinic found that only 10 percent of those people are truly penicillin allergic. In other words, 9 out of 10 people who think they have penicillin allergy are avoiding it for no reason. Even in people with documented allergy to penicillin, only about 20 percent are still allergic 10 years after their initial allergic reaction. It's not necessarily a permanent condition.

    Why is this important? Aren't there many other antibiotics you can use if you have penicillin allergy? Penicillin has been around since 1928. Penicillin and its related medicines include amoxicillin, methicillin and amoxicillin-clavulnate. These medicines are highly effective treatments for many bacterial infections, such as strep throat and ear infections. Of course, there are alternative antibiotics, but these are often much more expensive and carry a higher risk of side effects. Typically, these alternative antibiotics are broad-spectrum, meaning they fight many types of bacteria, both good and bad. That can lead to development of drug-resistant bacteria, or deadly “superbugs”. This increases the risk for all of us in the future of not having an effective antibiotic to treat our infection.

    How do you find out if you have penicillin allergy? Board-certified allergists can test you. First, the allergist will get a history from you about your possible allergy. Typical questions include: How long ago did you have the reaction? What type of reaction occurred, and how soon after you took the penicillin did the reaction appear? The testing is done on the forearm by pricking the skin with a needle. If the results are negative and there is no reaction, penicillin will be injected in the skin. These tests are not painful, and results are available in 15 minutes. A positive reaction may lead to some swelling and itching where the test was placed, which usually goes away within an hour.

    In very rare cases, an allergic reaction occurs. This can include hives, swelling, wheezing and/or difficulty breathing. The allergist is trained to treat this rare condition quickly if it happens. If all skin testing is negative, you may be given an oral dose of penicillin in the office. The oral drug challenge is used to verify that you don't have penicillin allergy. Usually, you'll be observed in the office for 30 minutes to make sure you have no problems.

    If you find out you don't have a penicillin allergy, notify your physicians that it's now safe for you to take penicillin. They can take “penicillin allergy” off your chart for good!

    A psychologist walked around a room while teaching stress management to the audience. As she raised a glass of water, everyone expected they'd be asked the “half empty or half full” question. Instead, with a smile on her face, she inquired. “How heavy is this glass of water?”

    Different answers are called out from the audience.

    She replied, “The absolute weight doesn't matter. It depends on how long I hold it. If I hold it for a minute, it's not a problem. If I hold it for an hour, I'll have an ache in my arm. If I hold it for a day, my arm will feel numb and paralyzed. In each case, the weight of the glass doesn't change, but the longer I hold it, the heavier it becomes.”

    She continued. “The stresses and worries in life are like that glass of water. Think about them for a while and nothing happen. Think about them a bit longer and they begin to hurt you. And if you think about them all day long, you will feel paralyzed and be incapable（无能力的）of doing anything.”

    It's important to remember to let go of your stresses. As early in the evening as you can, put all your burdens down. Don't carry them through the evening and into the night.

    Remember to put the glass down!”

    Comments:

    Aye Chan Aung－February 27, 2017 at 11:37am

    Short but valuable! It clearly teaches me how to deal with stresses.

    Nelson Malicdem－February 28, 2017 at 8:23 pm

    Wow! Thank the author and the one who submitted the article. I am experiencing a challenge when I read this. It gives me peace. What exactly is in the article is what I am doing. My burden actually paralyzes me without my knowing it. I put down the glass of water that I am holding. Thank you so much!

    Take advantage of this offer to stay in the middle of the magic and save up to 25 % on rooms at select Disney Resort hotels. Valid for stays most nights from May 28 through August 31. Book through July 14 this year.

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    Nottingham Goose (鹅) Fair started on the first Thursday in October and lasted 3 days. However, nowadays you won't find any geese there.

    The fair opened at 12: 00 on the Thursday by the Lord Mayor of Nottingham, but it has an interesting and shocking history.

    For starters, it wasn't always the largest fair in the area. And the main fair for the people of Nottingham in terms of trade and economy was the Lenton Fair held at Lenton Priory.

    In the Middle Ages the Lenton Fair overshadowed (使显得逊色) the Goose Fair in size and importance. Harrisons Calendar of Fairs for 1587 mentions the Lenton Fair but not the Goose Fair. However the Goose Fair competed with its local competitors and every year over 20, 000 geese from the Fens in Lincolnshire arrived to be sold to provide the traditional Michaelmas dish.

    It wasn't just for geese either. All kinds of things were sold at the Goose Fair: sheep, horses and cattle were also sold.

    The fair has been under threat of closure many times over the years. In 1764, they actually had cheese riots (暴乱) due to an increase of a third on the price of cheese compared with the previous year, which resulted in an attack on the stallholders (摊主) at the fair.

    By 1880 the fair was reduced to a three-day event, which started on the first Thursday of October. In 1928, the fair was moved from the market square to its present site in the forest which is far away from the city centre. Despite attempts throughout its history to prevent the fair, the income from rents paid by the stallholders is financially beneficial to the local government. So regardless of the cheese riots and the various attempts to prohibit it, Nottingham Goose Fair has survived to celebrate over eight centuries of fun.