Smoking is harmful. But as soon as you quit the habit, everything will be OK, right?

    Wrong

    New research has found that even if you give up smoking, the damage it has done to your genes(基因) will stay there for a much longer time. In the research, a team of US scientists studied the blood of 16,000 people. Among them, some were smokers, some used to smoke, and the rest were non-smokers. Scientists compared their genes and found that more than 7,000 genes of smokers had changed—a number that is one-third of known human genes.

    According to NBC News, both heart disease and cancer are caused by genetic changes. Some people may have had the changes when they were born, but most people get them in their day-to-day lives while doing things like smoking.

    When you stop smoking, a lot of these genes will return to normal within five years.

    This means your body is trying to heal (治愈) itself of the harmful effects of smoking. But the changes in some of the genes stay for longer. They can stay for as long as 30 years. It's almost like leaving a footprint on wet cement (水泥)—it will always be there, even when you've walked away and when the cement becomes dry.

    Although the study results may make people unhappy, there is a bright side: the findings could help scientists invent medicine to treat genetic damage caused by smoking or find ways to tell which people have heart disease or cancer risks.

    We humans spend about one-third of our lives asleep. This may sound like a lot of time, but it is not wasted. Sleep not only helps us stay healthy but it also helps our brains remember. Our brains need good sleep to remember what we do and learn during the other two thirds of our lives when we are awake.

    Researchers at the University of Wisconsin-Madison have found that sleep helps improve brain performance by shrinking(收缩)synapses in the brain. A synapse is the area where cells pass messages to other cells.

    Scientist Chiara Cirelli is a leader at the school's Center for Sleep and Consciousness. She told the reporter that sleep is when the human brain mixes information it has learned while awake into its general collection of knowledge. Meanwhile, the brain forgets unimportant details. This forgetting is important. It makes space for new learning and new memories.

    Cirelli said that the Centers research began with this hypothesis(假设): We sleep so that our brain can repair and refresh itself. She said the idea seems simple and reasonable. However, testing and discovering how it works has been extremely difficult.

    Synapses are only about 20-40 nanometers(纳米)wide. The team began their study by measuring the size of the synapses to look for changes in these already tiny spaces between nerve cells. Cirelli says the process(过程) is difficult because"all the actual measurements of the synapses have to be done by hand." The team had to wait until improvements in laboratory technology made it possible to see these tiny changes. A University of Wisconsin press release called the research a"huge job." Many research specialists worked for four years to photograph, rebuild and study certain areas of a mouse brain. The report also said the scientists measured 6,920 synapses.

    Cirelli says they found that our synapses shrink as our brains clean themselves during sleep. We wake up refreshed and ready to fill those synapses with new information. The research findings are the result of years of hard work at the University of Wisconsin Madison. The researchers published their findings in the journal Science.

    Humans are much worse at estimating risk than we think we are. While we overestimate the risk of rare but disastrous occurrences, such as being attacked by a shark, many of us seriously underestimate the risk of behaviors that reduce our lifespan (寿命), such as smoking.

    In fact, there are two types of risks — acute and chronic. Acute risks are those that may kill you immediately, such as a car accident.

    Chronic risks don't kill you immediately but rob you of your life a little at a time. If you choose to eat an unhealthy diet, for instance, you may appear to be getting away with this, but you risk developing illnesses in future that may shorten your life.

    The problem is we value things much less when they occur in the future. Distant events are abstract — we don't know how and when they might affect us -~ so we care less about them.

    Take smoking for example. It is just about the worst choice you can make for your health. Every two cigarettes that you smoke takes 30 minutes off your lifespan.

    In contrast, eating vegetables is clearly very good for you, with each serve increasing your lifespan by two hours. This is a massive health gain and clearly should be a strong motivator for you to eat healthily.

    Drinking coffee is also good for you, though with limited health gains. Each cup of coffee (assuming you drink reasonably), is associated with approximately a ten-minute gain in your lifespan.

    Even drinking alcohol may add to your lifespan, with each serve adding 30 minutes to the length of your life. But this health gain is only true for the first drink; following drinks shorten lifespan. Alcohol also causes an acute risk when consumed in excess. Too much drinking gives you a 25 in one million chance of sudden death.

    We shouldn't be too nervous about exposure to risks. Life is all about making decisions about risks and rewards, and we all have a different starting point for what we consider acceptable risks to take. Even if we don't always make the healthiest decisions, at least we can make ones that are fully informed.

    As most people know, in the last few years, sandstorms have swept across many cities and areas of North China, polluting the air and disturbing daily lives of human beings. People look dirty and suffer many kinds of illnesses, such as breath difficulty. The sandstorm is such a serious problem that it has not only weakened the industrial and agricultural development of our country but also caused a lot of trouble to the living conditions of the Chinese people.

    Therefore, effective measures should be taken as soon as possible to stop its happening. So how should we deal with the frightening sandstorms?

    Some experts offer practical advice as follows: For one thing, more money ought to be put into tree planting and forest protection in order to keep more water on the Earth. For another, government of all countries should make laws on environment protection. For example, banning the use of throw-away chopsticks and punishing illegal tree cutting. Scientists should also study and find ways to lower the grade of its destruction and to improve the environment. As for some schools, education about sandstorms should be spread properly and timely to make more and more people attach great importance to this problem.

    How people look forward to sunny days with soft wind touching their faces now and forever! The golden days can come back so long as we try our best to protect the natural environment from today on. And the fact is that what I expect is not just a dream. There are some sweet fruits from the early efforts.

    In recent years, terms like "going green" and "eco-friendly" have become buzz words on talk shows, commercials and product packaging. The term "eco-friendly" has been used for so many different products and practices.

    Eco-friendly Car Race

    Can you imagine a car racer is so eco-friendly that its tyres are made from potatoes, its body is created from hemp (大麻) and rapeseed oil and it runs on fuel made from wheat and sugar beet (甜菜)? The one-seater racing car called Eco One is built by experts from Warwick University, who hope that Eco One will be adopted by the automotive industry. It is sold at $ 51,000.

    Pollution-sensitive Dress

    Don't be caught outside unaware of pollution levels in the air. The pollution-sensitive EPA Dress by Stephanie Sandstrom notices pollution in the air accordingly. This dress ­ which is actually quite pretty ­ looks like you pull it from the bottom of the dirty laundry pile when the air is dirty. It might protect your health by advising you to stay indoors for the day, but it won't do you any favor if you're meeting with clients.

    Eco-friendly Umbrella

    Traditional umbrellas come with a fixed surface. Although it is changeable, you cannot replace it easily. This eco-friendly design is more flexible. It is actually only an umbrella skeleton(骨架)without any surface, which can be folded, so you can put anything such as newspapers, plastic bags or whatever you want to serve as the protecting surface.

    Eco-friendly Moss (苔藓) Carpet

    It is said that walking on fresh grass increases your blood circulation. The Moss Carpet, created by Nguyen La Chanh, looks at getting the grass to your feet. The mat includes ball moss, island moss and forest moss. The humidity (湿度) of the bathroom ensures that it grows well. And that's why you need to place it there and not anywhere else.

    Some years ago, Michel-Andre found himself staring at the body of a dead whale on a beach in the Canary Islands. It was obvious that the animal had been struck violently by a ship——but why? Only later, after surveying the whales which lived in the area and measuring the increase of sound pollution from ships did it become clear that there was a link.

    The whales had become desensitised to the noise of approaching boats and were being struck by them, often seriously. "We never thought that this could be something that could kill," recalls (回忆) Andre, who is the director of the Laboratory of Applied Bioacoustics at the Technical University of Catalonia, Barcelona.

    Andre has spent 20 years developing an advanced system to better understand why incidents like this happen. His underwater microphones have exposed a world of deafening sound and animal communication never observed with such clarity(清晰) before.

    It was not an easy task. Sound waves don't travel through water in the uniform, predictable way they do through the air. Instead, the temperature, salinity (盐度) and, flow of water have great effects on their path.

    What can be done? One solution is to change shipping routes to courses where ships are statistically less likely to meet animals. It's also possible to slow ships down to 18km/h or less, which is less likely to seriously injure a whale.

    As for dealing with the root cause of the problem, the UN's International Maritime Organisation has already published guidelines on how to quieten ships, but it will be a while before the effects of such changes might be observed.

    "The ocean is not our world," comments Andre. But it is ours to look after. And thanks to his work, we can better understand the effects of subsea sound pollution.