Harmful microbes like bacterias, viruses and other germs are pathogens. They may enter your bodies and make you ill. The immune system is the body's defence system that protects you from illness and disease caused by the pathogens.

    The immune system is made up of non﹣specialized defences such as skin, tears and the acidic juice produced by the stomach, keeping you from the pathogens. It also has some highly specialized defences, which are different kinds of immune cells, grouped into phagocytes and lymphocytes. Phagocytes are a type of white blood cell. They are swimming around in your blood stream, always on the lookout for antigens﹣the pathogens that have entered your bodies. Whenever they see one, their will eat it. However, some antigens are hard to find and kill. Then lymphocytes, which are also white blood cells and the main types are B cells, T helper cells and T killer cells, Will be the killers of the sneaky antigens.

    B cells, T helper and T killer cells work together to find and kill these antigens. B cells produce substances, called antibodies, which stick to the antigen. When that happens, it will tell the T helper cells to come over and either: 1. help the B cells kill the antigen, or 2. call the phagocytes or T killer cells to move in for the kill. Once a B cell or a T cell attacks an antigen, they create cells to "remember" it. Those "memory cells" hang out in your blood if they see the same antigen again, they quickly recognize, it so your immune system can act faster at killing it.

    The immune system is more powerful than you probably imagine. Scientists from the University of Pennsylvania recently took immune cells from three patients with leukemia, then genetically changed them into "serial Keller "cells to attack cancer cells. The study was small but the results were groundbreaking. The modified immune cells increased at least 1, 000 times in the body and killed all the cancer cells. Therefore, more "memory cells" were created.

    The immune system can be developed. Eating lean protein food （beef, beans ）and food rich in vitamins A, C, and E（sweet potatoes, carrots ）, taking a 30﹣minute walk every day and reducing your stress levels, etc. will help you achieve it.

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    You don't need to get in a time-travelling machine to see how technology will change our lives, such as the way we shop. Several new technologies that are to change your buying habits already appear. Let's see what's in store for your future shopping.

    Try it on, virtually（虚拟地）. Want to shop online for a new pair of glasses? You don't need to guess which pair looks best on you—use the eBay Fashion iPhone app to try a pair of glasses you're checking out on a picture of your face. But what about buying something bigger? Thanks to Microsoft Kinect's action tracking（跟踪）camera, you can cover clothes on your screen body. You can even choose the background of your virtual fitting room to improve your shopping experience.

    Get a perfect, custom fit. Everyone's body is shaped differently. To get a perfect fit, you sometimes have to get your clothes changed. But by using 3D scanning technology, all the clothes you buy will fit your body perfectly. Some companies scan（扫描）your body using High-tech to get the real sizes, so they can make special clothes just for you.

    High-tech shopping carts（推车）and checkout counters（收银台）. High-tech shopping carts could be common in malls and supermarkets in the future. Microsoft Kinect-enabled carts are under test. The cart can follow you along the aisles（通道）, controlled only by your movement and your voice.

    In the United States, several supermarkets use a certain set called “Scan It” that gives buyers the freedom to scan products on their own while they shop. If we don't want to wait in line before the checkout counters, we can use Toshiba's new object Recognition Scanner. The machine identifies（辨认）a product as soon as it's placed in front of a camera just by its shape and color, even if it has no bar code.

    What will man be like in the future — in 5,000 or even 50,000 years from now? We can only make a guess, of course, but we can be sure that he will be different from what he is today. For man is slowly changing all the time.

Let us take an example. Man, even five hundred years ago, was shorter than he is today. Now, on the average, men are about three inches taller. Five hundred years is a relatively (相对地) short period of time, so we may suppose that man will continue to grow taller.

    Again, in the modern world we use our brains a great deal. Even so, we still make use of only about 20% of the brain's capacity (容量.) As time goes on, however, we shall have to use our brains more and more and finally we shall need larger ones! This is likely to bring about a physical change too. The head, especially the forehead, will grow larger.

    Nowadays our eyes are being used too much. In fact, we use them so much that very often they become weaker and we have to wear glasses. But over a very long period of time it is likely that man's eyes will grow stronger.                      

    On the other hand, we tend (有…的趋势) to make less use of our arms and legs. These, as a result, are likely to grow weaker. At the same time, however, our fingers will grow more sensitive (敏感的) because they are used a great deal in modern life.

    What about hair? This will probably disappear from the body altogether in course of time because it does not serve a useful purpose any longer. In the future, then, both men and women are probably to be hairless!

    Perhaps, all this gives the impression that future man will not be a very attractive (有吸引力的) person to look at! This may well be true. All the same, besides these changes, future man will still have a lot in common with us. He will still be a human being, with thoughts and feelings similar to our own.

    When we talk about the universe, we mean not only the earth, the sun and the moon, but also the stars and space between them. There are millions of stars in our sky. The sun is one of them. Around it there are eight big planets moving, including the earth. The moon is our nearest neighbor in space. If you look at the sky on a clear night, it is possible to see about 3, 000 stars. They look small, but they are really very big hot balls of burning（燃烧着的）gas. Some of them arc huge（巨大的）, but others are much smaller like our planet Earth. The biggest stars are very bright, but they can only live for a short time. Every day new stars are born and old stars die.

    All the stars are very far away. The light from the nearest star（except the sun）takes more than four years to reach the earth.

    Hundreds of years ago, people used stars, like the North Star, to know which direction（方向）to travel in.

Today you can still see that star.

    Virtual (虚拟的)reality is a way to create a computer-made environment that brings the user into a virtual world. If you ever have put on a VR headset, you would know exactly what I am talking about. From an experiential view we do understand the idea, but what about the technical backend that goes into making it all possible? In this blog, we will understand the technology behind virtual reality and the basic terms about the development of a virtual ecosystem for a VR headset.

    The primary subject of virtual reality is simulating (模拟)the vision. Every headset is to perfect their method to create an immersive (浸人式)3D environment. Each VR headset puts up a screen or two in front of eyes, keeping the user away from any interaction with the real world. Two autofocus lenses (自动对焦镜片)are generally placed between the screen and the eyes that change based on eye movement and positioning. The vision appears on the screen either by using a mobile phone or HDMI line connected to a PC.

    To create a truly immersive virtual reality, there are certain requirements a frame rate (帧 率)of at least 60 fps, a refresh rate and at least 100﹣degree field of view (though 180 degrees is perfect). If either of these doesn't work according to the standards, the user will experience too big of a time difference between their actions and the response from the screen. We need the response to be less than 20 ms (1/1000 second) to fool the brain which is achieved by joining all the above in the right proportion (比例).Another matter that needs to be looked at here is to prevent netsickness because of the differences between the frame rate and refresh rate.

    Apart from the image, there are certain other things that go into creating an immersive VR experience, holding the user's attention completely in the virtual environment. For example, sound effects, when put with the image, can create very attractive effects. By using a headphone and 3D sound effects, the user can totally believe in the virtual environment. While perfecting sound effects, proper care needs to be taken about the consistency (一致)between the pictures and the sound. If you start playing frightening music in the background of a happy scene, it will just put the user off.

    In future, we will see rapid progress in creating a truly immersive digital experience. With leading players like Google, Microsoft, Oculus, and HTC making great efforts to improve the capabilities (性能),we are not far from achieving a virtual reality that would feel so much better than the real world. If you would like to develop a VR app for your business, then feel free to get in touch. With over 10 years of experience in mobile technologies, we can make every dream a reality.

    Different weather makes people feel different. It influences health, intelligence(智力) and feelings.

    In August, is very hot and wet in the southern part of the United States, People there have heart trouble and other kinds of health problems during this month. In the Northeast and the Middle West, it is very hot at some times and very cold at other times. People in these states have more heart trouble after the weather changes in February or March.

    The weather can also influence intelligence. For example, in a scientific report, IQ (智商) of a group of students was very high when a very strong wind came, but after the strong wind, their IQ was 10% below. The wind can help people have more intelligence. Very hot weather, on the other hand, can make it lower. Students in many schools of the United States often get worse on exams in the hot months of the year (July and August).

    Weather also has a strong influence on people's feelings. Winter may be a bad time for thin people. They usually feel cold during these months. They might feel unhappy during cold weather. But fat people may have a hard time in hot summer. At about 18℃, people become stronger.

    Low air pressure may make people forgetful. People leave more bags on buses and in shops on low-pressure days. There is a "good weather" for health. People feel best at a temperature of about 18℃.

    Are you feeling sad, tired, forgetful, or unhappy may be the weather's problem today?