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.”

    Try this: For an entire day, forget about the clock. Eat when you're hungry and sleep when you're tired. What do you think will happen?

    You may be surprised to find that your day is much like most other days. You'll probably get hungry when you normally eat and tired when you normally sleep. Even though you don't know what time it is, your body does.

    These patterns of daily life are called circadian rhythms（生理节奏）, and they are more than just habits. Inside our bodies are several clocklike systems that follow a roughly 24-hour cycle. Throughout the day and night, our inner clocks direct changes in temperature, body chemicals, hunger, sleepiness and more.

    Everyone's rhythms are different, which is why you might like to stay up late while your sister always wants to go to bed early. But on the whole, everyone is programmed to fell tired at night and energetic during the day.

    Learning about our body clocks may help scientists understand why problems arise when we act out of step with our circadian rhythms. For example, traveling across time zones can make people wake up in the middle of the night. Regularly staying up late can make kids do worse in tests.

    "There is a growing sense that when we eat and when we sleep are important parts of how healthy we are," says Steven Shea, director of the Sleep Disorders Program at Brigham and Women's Hospital in Boston.

    One way to learn about how our body clocks tick is to mess them up and see what happens. That's what neurologist（神经病学家）Frank Scheer and his workmates did in a recent study.

    Staying up night after night, their studies suggest, could make kids extra hungry and more likely to gain weight. And regularly sleeping too little, Scheer says, may be one cause of the recent increase in childhood obesity.

    Bike Share Toronto is the city's official bike share program, designed to give locals and visitors a fun, affordable and convenient alternative to walking, taxis, buses and the subway. There are 200 Bike Share Toronto stations and 2,000 bikes across the city, making Bike Share the most accessible way to get around and explore.

    How it works

    Become an Annual Member or buy a day Pass to access the system.

    Find an available bike nearby, and get a ride code or use your member key to unlock it.

    Take as many short rides as you want while your pass or membership is active.

    Return your bike to any station, and wait for the green light on the dock (停靠点) to make sure it's locked.

    Choose a plan

    For visitors

    Day Pass: $7. Unlimited 30-minute rides in a 24-hour period.

    3-Day Pass: $15. Unlimited 30-minute rides in a 72-hour period.

    For locals

    Monthly Pass: $25. Unlimited 30-minute rides for a month.

    Annual Membership: $90. Unlimited 30-minute rides for a whole year. The Annual Membership is the best deal for locals of Toronto and other frequent riders.

    The first 30 minutes of each ride is included with the membership or pass price. Avoid extra fees by dropping off your bike every 30 minutes at any other station. If you keep a bike out for longer than 30 minutes at a time, you will be charged an extra $1.50 for the first 30 minutes over, $4 for the next 30 minutes, and $7 for each additional 30 minutes after that.

    Contact us

    Customer Service: (855)898-2388

    Repair Service: (855)898-2378

    Corporation Partners: (855)898-2398

    Employment Opportunities: (855)898-2498

    After moving to the United States, immigrant groups trying to fit in tend to choose high calorie fatty foods in an attempt to appear more American, a new study finds. That's one reason why immigrants approach US levels of obesity within 15 years of moving to America.

The researchers also did an experiment that measured whether or not the threat of appearing un-American influenced respondents' food choices. After being questioned about their ability to speak English 75 percent of Asian-Americans identified a typical American food as their favorite. Only 25 percent of Asian-Americans who had not been asked if they spoke English did the same.

    When their American identity was called into question during a follow-up study, Asian-American participants also tended to choose typical American dishes, such as hamburgers and cheese sandwiches.  In that experiment, 55 Asian-Americans were asked to choose a meal from a local Asian or American restaurant. Some participants were told that only Americans could participate in the study. Those who chose the more typical American fare ended up consuming an extra 182 calories,  including 12 grams of fat and 7 grams of saturated fat (饱和脂肪).

    "People who feel like they need to prove they belong to a culture will change their habits in an attempt to fit in," said Sauna Cheryan, an author of the study and assistant professor of psychology at the University of Washington.

    "If immigrants and their children choose unhealthy American foods over healthier traditional foods across their lives, this process of fitting in could lead to poorer health." Cheryan added.

    Social pressures, the study concluded, are at the heart of the problem.  "In American society today, being American is associated with being white. Americans, who don't fit this image even if they were born here and speak English, feel that pressure to prove that they're American," said Cheryan.

    Dance Classes

    Ballet

    Ballet teaches grace, posture(姿势) and flexibility. Students focus on the use of proper ballet items(物品),expanding their knowledge of classical ballet techniques and improving motor skills for classical ballet practice. The class is a formal ballet class.

    Age 8-10

    September 7, 2019-May 16, 2020

    10:30 am-12:00 am on Saturday

    Creative Movers

    Students can explore creative movement, balance, focus, the development of skills, motor planning and balance. The class helps build strength, flexibility and self-confidence, and allows children to realize expression in a positive and encouraging environment.  Children use their imagination to celebrate movement and have lots of fun.

    Age 3-5

    September 7, 2019-January 18, 2020

    9:00 am-9:45 am on Saturday

    Jazz

    Jazz includes movements from both classical ballet and dance techniques. This class will focus on traditional jazz dance. Students will be introduced to jazz-style rhythms and movements. In order to ensure proper placement for your child, we invite all students to participate in a sample(示例) class. Students and parents work with program staff to meet students' personal dance goals.

    Age 5-6

    September 7, 2019-May 16, 2020

    2:00 pm-3:00 pm on Saturday

    Hip Hop

    Students will be introduced to several different aspects of hip hop dance including popping, locking, breaking and totting in a high-energy environment. Our hip hop instructors are highly knowledgeable and will provide students with a wonderful view of hip hop dance.

    Age 7-10

    September 7, 2019-May 16, 2020

    1:00 pm-2:00 pm on Sunday

Despite extreme cold, cruel ice and being brushed off as mad, Slovenian Davo kamicar became the first person to ski non-stop down Mount Everest. After a dramatic fall over almost sheer cliffs of snow, stones and ice, 38-year-old Kamicar returned to his base camp after five hours of skiing. "I feel only absolute happiness and absolute tiredness," he said. 

Due to the severe weather conditions, Kamicar flung himself back down the mountain as soon as he reached the top rather than have a rest as planned At one point, he had to speed overstretches of ice that collapsed and broke underneath him and could have sent him falling into the deep crevasses(裂缝) that dot the mountain.

The descent (下落) had been widely regarded as extremely dangerous. The Darwin Awards website, known for documenting foolhardy deaths, urged people to log on to their website and "keep your eyes peeled for a live Darwin Award". However, the only body to make the news was the corpse (尸体)of an unknown mountaineer which Kamicar zipped past as he descended one of an estimated 120 corpses, thought to litter the slopes." This mountain is always full of surprises. Seeing a dead man out there was still a shocking experience," he said. 

Thanks to strategically placed cameras on the mountain and one attached to his safety helmet hundreds of thousands of people witnessed the process online, which was one of the record highs ever of more than 650,000 hits. The website was once jammed as people tried to access the site.

A previous failed attempt had already cost Kamicar two fingers when he got frostbite as a fierce storm hit the peak. Coming from a skiing family and had his first Himalayan skiing expedition in 1989, he has been ever since tireless in raising funds and sponsorship for more expeditions, with Everest as the permanent goal.