Have you ever wondered why birds sing? Maybe you thought that they were just happy. After all, you probably sing or whistle when you are happy.

    Some scientists believe that birds do sing some of the time just because they are happy. However, they sing most of the time for a very different reason. Their singing is actually a warning to other birds to stay out of their territory.

    Do you know what a “territory” is? A territory is an area that an animal, usually the male, claims（声称）as its own. Only he and his family are welcome there. No other families of the same species are welcome. Your yard and house are your territory where only your family and friends are welcome. If a stranger should enter your territory and threaten you, you might shout. Probably this would be enough to frighten him away.

    If so, you have actually scared the stranger away without having to fight him. A bird does the same thing. But he expects an outsider almost any time, especially at nesting（筑巢）season. So he is screaming all the time, whether he can see an outsider or not. This screaming is what we call a bird's song, and it is usually enough to keep an outsider away.

    Birds sing loudest in the spring when they are trying to attract a mate and warn others not to enter the territory of theirs.

    You can see that birds have a language of their own. Most of it has to do with attracting mates and setting up territories.

    The Healthy Habits Survey(调查)shows that only about one third of American seniors have correct habits. Here are some findings and expert advice.

    ⒈How many times did you brush your teeth yesterday?

    Finding: A full 33% of seniors brush their teeth only once a day.

    Step: Remove the 300 types of bacteria in your mouth each morning with a battery­operated toothbrush. Brush gently for 2 minutes, at least twice a day.

    ⒉How many times did you wash your hands or bathe yesterday?

    Finding: Seniors, on average, bathe fewer than 3 days a week. And nearly 30% wash their hands only 4 times a day—half of the number doctors recommend.

    Step: We touch our faces around 3,000 times a day—often inviting germs(病菌)to enter our mouth, nose, and eyes. Use toilet paper to avoid touching the door handle. And, most important, wash your hands often with hot running water and soap for 20 seconds.

    ⒊How often do you think about fighting germs?

    Finding: Seniors are not fighting germs as well as they should.

    Step: Be aware of germs. Do you know it is not your toilet but your kitchen sponge (海绵) that can carry more germs than anything else? To kill these germs, keep your sponge in the microwave for 10 seconds.

    The Dunning-Kruger effect is a type of cognitive bias (偏见) in which people believe that they are smarter and more capable than they really are. Essentially, low ability people do not possess the skills needed to recognize their own incompetence. The combination of poor self-awareness and low cognitive ability leads them to overestimate their own capabilities. This phenomenon is something you have likely experienced in real life, perhaps at a holiday family gathering. Throughout the course of the meal, a member of your extended family begins spouting off on a topic, boldly announcing that he is correct and that everyone else's opinion is stupid, uninformed, and just plain wrong. It may be plainly evident to everyone that this person has no idea what he is talking about, but he talks continuously, blithely oblivious (忘乎所以) to his own ignorance.

    The effect is named after researchers David Dunning and Justin Kruger, two social psychologists. They found incompetent people are not only poor performers, they are also unable to accurately assess and recognize the quality of their own work. These low performers were also unable to recognize the skill and competence levels of other people, which is part of the reason why they consistently view themselves as better, more capable, and more knowledgeable than others.

    This is the reason why students who earn failing scores on exams sometimes feel that they deserved a much higher score. They overestimate their own knowledge and ability and are incapable of seeing the poorness of their performance.

    “In many cases, the incompetent are often blessed with an inappropriate confidence, encouraged by something that feels to them like knowledge.” Dunning and his colleagues have also performed experiments where they ask respondents if they are familiar with terms related to subjects including politics, biology, physics, and geography. Along with genuine concepts, they added completely made-up terms. In one such study, approximately 90 percent of respondents claimed that they had at least some knowledge of the made-up terms.

    So what can you do to gain a more realistic assessment of your own abilities? Instead of assuming you know all there is to know about a subject, keep digging deeper. Once you gain greater knowledge of a topic, the more likely you are to recognize how much there is still to learn. Another effective strategy involves asking others for constructive criticism. While it can sometimes be difficult to hear, such feedback can provide valuable insights into how others perceive your abilities. Even as you learn more and get feedback, it can be easy to only pay attention to things that confirm what you think you already know. In order to minimize this confirmation bias, keep challenging your beliefs and expectations and seek out information that challenges your ideas.

    Best Southern winter Beer Festivals to Challenge Your Taste

    Bluffton International Craft Beer Festival

    This festival is considered to be "The Best Little Beer Fest in the US". This festival shows over 125 beers from more than 40 breweries (啤酒厂) across the US and focuses on unique and new beers that you usually can't find in a grocery store. The festival even has hourly surprises of a limited quantity of rare beers as well as food for those who can arrive in time.

    Bayou Beer Fest

    The Bayou Beer Fest is the premier beer festival in the Bayou Region of southern Louisiana and is held at the historic 19th century sugar farm, making it a truly memorable beer festival. The festival will provide hundreds of beers from state-based, national, and even international breweries, of course, there will also be food to purchase, and several Louisiana-style musical acts to keep the festival alive.

    Key Largo Brew on the Bay

    It's actually winter at this beer festival held in the largest section of the Florida Keys. The festival covers two days, and will feature at least 40 different breweries, including local breweries. Besides, because it does harm to your health to enjoy beer on an empty stomach, Brew on the Bay will feature a food court, with fresh Florida lionfish, fish sandwiches and shellfish.

    Yaga's Chili (辣椒) Quest& Beer Fest

    Beer and chili go together like peas and carrots, so you will not want to miss the annual Yaga's Chili Quest Beer Fest. The festival will feature over 100 import beers, including rare finds and a few surprises prepared for all people present. Of course, there will also be a variety of tasty chili for you to try.

    The clock always seems to be ticking rather too fast in the doctor's office and the queue of patients outside the door seems to be pressing rather too hard. Some say it's high time for the model of short, sharp one-to-one appointments to give way to shared medical appointments (SMAs共享医疗预约).

    SMAs are doctor-patient visits in which a group of patients receive patient education and counseling (咨询), physical examination and medical support in a group setting. Typically SMAs are designed to have one or more doctors attend to a group of patients who share a common illness or medical condition. In contrast to one-to-one visits, SMAS provide a longer appointment time-frame as well as the opportunity for patients to have improved access to their physicians and meanwhile pick up additional information and support from peers.

    However, doctors who have pioneered the shared appointment approach report that there are significant challenges involved. Dr. Sumego, director of shared medical appointments, Cleveland Clinic, identifies culture change as the most significant challenge. Physicians and nurses are trained in a model of personal service and privacy; the SMA approach is a fundamental challenge to those fixed ideas. They need shared goals and a way of testing the innovation against agreed standards. Dr. Sumego says, "The physicians may be worried about the possible chaos and efficiencies that are marketed. They also have to make the patients understand what their appointment is, and what the expectation is."

    "So, if an organization was looking to start shared medical appointments, I would advise them to start the buy-in from a few champion physicians, develop the work-flow and develop some experience. Provide some support behind what that best practice should look like. Create some standards so that, as the concept spreads, you can employ that experience to start the next shared medical appointments and the next."

    Scientists can figure out a movie's emotional tone from the gasps(喘气) of its audience. These gases could point the way to a subtle(微妙的，精细的) form of human communication, a new study suggests.

    "When you see a movie, you can hear the music and see the pictures. However, you don't realize here are chemical signals in the air. And they, too, could be affecting you, says Williams, who led the study. As an atmospheric chemist, he studies the chemical makeup of the air around us.

    Williams started out measuring the air in a soccer stadium. He noticed that levels of carbon dioxide and other gases changed wildly whenever the crowd cheered. That got him wondering -- Could the gases people breathe out be influenced by emotions?

    To find out, he went to the movies.

    Williams and his coworkers measured air samples collected over six weeks in two movie theaters. Overall, 9,500 movie goers watched 16 films. They included a mix of comedy, romance, action and horror films. Among them were The Hunger Games, Catching Fire, Carrie, and Walking with Dinosaurs. The researchers gave scenes from the movies such labels as "suspense(悬疑)", "laughter" and "crying". Then they looked for hundreds of chemicals in the air that showed up as people were watching particular movie scenes.

    And certain scenes had distinct chemical "fingerprints". Scenes that had people laughing or on the edge of their seats were especially distinctive. During screenings of The Hunger Games, levels of carbon dioxide and isoprene got to the highest at two suspenseful moments. Because isoprene is related to muscle movement, the researchers think tense movie moments likely led to its spikes(尖峰). Williams and his colleagues think the increase in carbon dioxide was due to the viewers' increased pulse and breathing rates.

    Scientists need more data to make stronger links between human emotions and what's in their breath. But Williams can see potential practical uses. Companies, for instance, could quickly measure the air during tests to see how people feel about new products. He pictures future studies recording other body variables(变数) as well. These might include heart rate and body temperature, for instance. "It's something to find out."