Dust on furniture may be bad news for waistlines (腰围). But it's far too early to add dusting to a weight-loss plan. Dietary fats and other materials that make up indoor dust can send a signal to human fat cells, telling them to grow. That process, in turn, might slow the body's rate of burning energy. Such changes could add to any weight problems a person might have.

    “We don't know what that means to long-term health and certain diseases yet,” says Heather Stapleton, one of the study's authors. But she notes that her team's findings also raise a question of whether pollutants in dust might play some role in the growing, global problem of obesity (肥胖).

    Stapleton and her colleagues collected dust from homes and offices. Studies found that some materials in the dust could turn on a protein (蛋白质) called PPAR-gamma 1. It's found in many human tissues. Turning this protein on can cause fat cells to grow. Researchers think this protein may be involved in obesity. But a second study now finds evidence that certain fats are mostly to blame. Cooking oils may send out some of these fats into the air, where they eventually find their way into house dust. Or, the authors say, the fats might enter house dust as part of the hair or skin cells shed (脱落) by people or pets.

    “While the findings are amazing,” says Mitchell Lazar, another study author, “these findings need to be taken as very limited.” Indeed, he adds several cautions about how the findings should be understood. “For one thing, people eat these fats in foods all of the time. That is likely to be a lot more than would be consumed from indoor dust,” he said.

    On a Saturday morning earlier this September, the world got its first look at the Strati. This electric vehicle is unlike any other currently on the road. It rolls on four wheels, but its body and chassis(底盘) weren't built in a factory. Instead, Strati's designers used a technology called 3-D printing. It created those parts of the car in one piece, from the ground up.

    “Compared to a typical vehicle on the road, the Strati definitely looks different,” says Greg Schroeder, a senior research engineer at the Center for Automotive Research in Ann Arbor, Mich. He did not work on the new car. His organization studies trends and changes in th e auto industry.

    It took 44 hours to print the new car at the International Manufacturing Technology Show in Chicago. Over the next few days, the car's designers installed additional parts. These included the car's engine, brakes and tires. Then, early on September 13, Jay Rogers climbed into the car, started its engine and drove the vehicle onto the street. Rogers helped found Local Motors. It's the Arizona-based company behind the Strati. Two weeks later, his team printed a second Strati, and just as fast, at a fair in New York City.

    Justin Fishkin, a local Motors official, sees the Strati as a window into the future. Today, car buyers are limited in their choice of a vehicle. They can order only what car companies have already designed. But in the future, he says, you may be able to design your own car online and then get it printed to order.

    Manufacturing experts say 3-D printing has begun to revolutionize how they make things. The technology has been around for decades. But these machines used to be so expensive that only large companies could afford them. In the last few years, though, that has changed. Many of the machines are now inexpensive enough for small companies—or even individuals —to own. Some local libraries make them available to the public. High Schools are beginning to use them in classrooms. Wide access to these printers means people can now design and print a wide variety of new things.

    The car's printer is a one-of-a-kind device.

    The technology behind the 3-D printer used in Chicago is an example of additive manufacturing. This proce ss builds solid objects, slice by slice, from the bottom up. (“Strati” means layers, in Italian.) A mechanical arm moves a nozzle from one side to another, back and forth. As it moves, the nozzle deposits a liquid—often melted plastic or metal (but it could be food, concrete or even cells) —that quickly hardens or bonds to become solid or semi-solid. This creates a single, thin layer. Once a layer is complete, the printer starts depositing the next one.

     “There's a lot of interest in 3-D printing in the auto industry,” says Schroeder. Right now, the technology is particularly useful for building models of cars or car parts.

    To compete with current auto manufacturers, the 3-D printer would have to increase in a hurry, Schroeder says. By contrast, he notes, a Ford F-150 pickup truck rolls off an assembly line at a rate of roughly one per minute. To print as many Stratis would require many more printers. Schroeder says he doesn't see 3-D printing soon taking over for such high-volume manufacturing. But, he adds, “Who knows what will h appen in the long term?”

    Scientists at Oak Ridge National Laboratory in Tennessee designed the 3-D printer used in Chicago. Lonnie Love, a research scientist at the lab, led the effort.

    Additive manufacturing often is slow and expensive. It also may produce materials that are unreliable, Love says. So for two years, his team searched for ways to make 3-D printing better. They built new machines and tested them over and over.

    All of that work paid off: their new machine is fast and uses less expensive material than earlier printers. In addition, it prints a plastic embedded with fibers of carbon to produce a stronger material. This helps ensure the material won't crack or break under pressure.

    Yesterday I work up to the sound of music on my couch in my fifth floor apartment downtown. I couldn't possibly tell you what song was playing because my monologue of things to do that day had already begun. My thoughts ranged from what deals needed my attention today to what is the meaning of life. I felt as if it was going to be one of “those days”.

    After taking my son to school and glancing at my calendar, I noticed I was meeting my 85-year-old friend Harry. I remembered that we first met at a glass shop. I needed a new window and he was talking to the store clerk about his glass fireplace insert needing replacement. As I stood behind him in line, I found not how this old man funny and compassionate at the same time. By the end of his discussion I was so entertained that I decided to drum up a conversation with him. That was how our friendship began. I later learned this gentleman was originally from the mid-west and grew up on a farm. At 17, he joined the army and travelled the world until his late 40's. After the retirement, his wife passed away and now he lives alone in his three-bedroom home.

    We met at the appointed time. I promised to take him to lunch anywhere he wanted to go and he said, “I am a simple man; let's go to Taco Bell. Furthermore I don't need a pat on the back because it is only 18 inches away from a kick in the rear.” We both laughed as we got into the car.

    As we pulled into the parking lot of Taco Bell, Harry jumped out of the car and told me, “I have to go into the donut(甜甜圈) shop next door before going to Taco Bell.” Of course I agreed and in we went. He immediately walked in and began having a joke with the owner of the shop in his fashion. They bantered as she gave him a dozen donuts and off we went. I couldn't help but ask him, “What are the donuts for?” He quickly replied, “You will soon see.”

    As we opened the door to Taco Bell, the line was very long. It was lunch time. People were on their cell phones. Babies were crying and the waiters looked stressed and burnt out. Harry and I were waiting in line chatting about nothing until we reached the front of the line. As he walked to the counter, all the waiters began smiling. He placed the box of donuts on the counter and said, “These are for you and other staff.” Instantly, the mood in the restaurant changed. This single act of kindness made the customers, the waiters, the kids and even me take a look internally and ask: when was the last time we did something nice for a stranger?

    What was most amazing to me was earlier that morning I wasn't thrilled with my life. It felt like it was just another day. Watching this gentleman spend 6 dollars on donuts and provide them for the staff in a packed restaurant at the lunch rush hour changed my outlook on life. If you don't believe me, try it yourself. Take the approach in life that you make an effort to do the little things in order to make people feel appreciated on a daily basis. You will see that your life will be better and you will have less of “those days” I was talking about earlier in this article.

    In the professional or career world, a gap year is when one stops their formal work life to pursue other interests. However, today gap year refers mostly to a year taken between high school and college.

    During this gap year, American students engage in advanced academic courses, extra-academic courses and non-academic courses, such as yearlong pre-college math courses, language studies, learning a trade, art studies, volunteer work, travel, internships(实习), sports and more.

    British and European students, however, take a much more vacation style approach to the “Gap Year” by generally working for 3-6 months and then traveling throughout the globe for the remaining time before college begins. This is intended to expand the mind, personal confidence, experiences, and interests before college.

    Let's look at the gap year in the following countries:

Denmark

    Denmark has tried to limit the number of students who take a year out, punishing students who delay their education to travel abroad or work full-time. In 2015, it was announced that fewer students than before had taken a year out.

India

    In India, the practice of taking time out after high school education, popularly called a drop year, has been on a quick rise in recent years, primarily students deciding to enroll in coaching institutions to prepare themselves for rigorous(严格的)college entrance examinations. However, using that year for travel is still not common.

Republic of Korea

     In republic of Korea, gap year is defined as time for the youth to think about directions of their lives by going through gap year programs such as voluntary activity, career exploration, education, having a relationship, internship and enterprise while he/she pauses studying.

United Kingdom

    In the United Kingdom a year out is a common choice before university, again to travel or volunteer, gaining life experience. All universities seem to welcome gap year applicants, no different from going straight to university from previous education.

    According to the Associated Press (AP), a Chinese scientist claims he successfully created the world's first genetically-edited babies.

    Chinese researcher He Jiankui, a research professor at China's Southern University of Science and Technology in Shenzhen, said he had edited DNA of twin girls born a few weeks ago. ①

    He's claims were immediately criticized by some scientists as unsafe and unethical. This kind of gene editing is forbidden in the United States and many other countries. ②Such changes to a person's DNA can pass to future generations and risk harming other genes.

    In interviews, He Jiankui defended his work. He said he had performed the gene editing to help protect the babies from future infection of HIV, the virus responsible for the disease AIDS. He said the process had “worked safely” and the twin girls were “as healthy as any other babies.” He told the AP he felt a strong responsibility “not just to make a first, but also to make an example” for future research. “Society will decide what to do next,” he said.

    When He's claims became public, the university made a statement saying his work had “seriously went against academic ethics and standards.” University officials said they had no knowledge of his research and had looked into the case. ③

    China's National Health Commission was “highly concerned” about the claims and ordered local health officials “to immediately look into” He's activity. “We have to be responsible for the people's health and will act on this according to the law,” the commission said.

    Scientists discovered in recent years a new way to edit genes that make up a person's DNA throughout the body. The tool, called CRISPR-cas9, makes it possible to change DNA to supply a needed gene or take one away that is causing problems. So far the tool has only been used on adults to treat deadly diseases, and the changes only affected that person.

    ④Kiran Musunuru, a scientist from University of Pennsylvania, told the AP that if such an experiment had been carried out on human beings, it could not be “morally or ethically reasonable.” Julian Savulescu, a medical ethics expert at Britain's University of Oxford, agreed. “If true, this experiment may cause disasters,” he told Reuters.

    However, one well-known geneticist, Harvard University's George Church, defended the attempt to edit genes to prevent infections of HIV. He told the AP that since HIV is “a major and growing public health threat” he finds such experiments “valuable.”

    Nowadays six Amazon Scout delivery robots rolled out in a pilot program in Snohomish County, Wash. The robots carry meals, groceries and packages to homes and offices in this region just north of Seattle. They have appeared on the sidewalks of London, Beijing and other cities and communities worldwide. These machines must overcome pedestrian legs, naughty dogs and broken pavement, which raises some questions.

    These services are gaining attraction as a growing number of city residents expect immediate or scheduled delivery for just about everything. Between 2017 and 2018 online retail sales in the U.S. increased by 16 percent. On the final step of all these deliveries, called the last mile, humans on bicycles, motorized scooters (电动车) or large delivery trucks typically deliver packages. All the vehicles compete for space on busy urban streets. "Deliveries are trending upwards in all crowded city centers, and if city and state leaders don't start thinking about creative solutions like robot deliveries, we can expect even worse traffic jams," says Paul Mackie, director of a transportation policy research center in Arlington.

    A study by this center found 73 percent of delivery vehicles in Arlington were parked outside of authorized areas, often blocking bike lanes and crosswalks. By moving the last step of deliveries from the road to the sidewalk, cities could reduce traffic jams and solve the parking problem entirely, Mackie says.

    Companies such as Amazon are not developing this delivery technology simply to clear up urban traffic. Self-driving vehicles and sidewalk robots could cut down last-mile delivery costs in cities by as much as 40 percent, according to a 2018 report by a consultancy firm. A delivery robot can cost thousands of dollars to manufacture, and most currently require human management and conservation. But in the long run companies that use autonomous delivery vehicles in the next several years could end up saving billions of dollars, the report stated.