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.

    A Chinese scientist's attempt to produce the world's first gene-edited babies who are immune to HIV has caused floods concern.

    In an online video posted on Monday, He Jiankui, a biological researcher, announced that a pair of twin baby girls, Lulu and Nana, was born healthy a few weeks ago with genetic editing technology that can prevent them from being infected with HIV.

    He, who was believed to be in Hong Kong on Monday to attend the Second International Summit on Human Genome Editing, could not be reached for comment. But his announcement sparked a heated argument concarning medical ethics（伦理）and effectiveness.

    The Shenzhen Health and Family Planning Commission said on Monday evening that it had not received any ethical assessment application for the study, which is required as a prior condition for such experiments.

    More than 120 scholars from universities and institutes with high status from China and abroad,such as Tsinghua University and the Massachusetts Institute of Technology (MIT),strongly condemned the research in a signed statement, saying the “research” lacks effective ethics inspection, and it amounts to human experimentation,which is “crazy”.

    In the statement, published on Sina Weibo, the scientists said any attempt to make changes to human embryos with genetic editing and give birth to such babies involves high risk as an inevitable part, due to inaccuracies in existing genetic editing technologies.

    “Scientists all over the world dare not make such attempts due to the huge risks and more importantly, ethics. The government must make quick legal moves to strictly supervise（监督）such research. The Pandora's Box has been opened, and we may still have a chance of closing it before it is too late,”the statement said.

    Tsui Lap-chee, president of the Academy of Sciences of Hong Kong, said a lot of issues may occur in gene editing. If one gene is edited, it will affect others that interact with it. And the whole genome, a collection of genes, may also be affected.

    When I was growing up, Mother's Day was as important as Christmas.

    The energy around the house was always positive（积极的）, mostly thanks to my father who made sure that his kids appreciated their mother, We would clean the house, and Mum got breakfast in bed in the morning and didn't have to lift a finger all day. And in the evening, we went to a restaurant for a traditional Mother's Day dinner.

    What I learned from my father over the years, was that no matter what, he always put my mother before himself. He absolutely loved her and never let her forget that. And from my parents, I learned a thing or two about how to love.

    I maintain（保持） my father's Mother's Day tradition with my wife. Growing up, I learned that showing affection to the woman you love or who gave birth to you is an important part of life. You see, it goes both ways, and the love you have for your mother comes back to you again and again.

    Believing that and feeling it when you can may keep you from being lonely, even if your mum isn't close by or has passed away. There are a number of us who no longer have a mother in our lives, and truth be told, there are often times when I wish my mum were still here to comfort me. So instead, I remember the times she did just that. It makes me smile, and somehow, those memories of a more simple and loving life give me the comfort I'm looking for.

    My wife's mother is still around, however, and it's great to have that "mother energy" in my life still. Having this relationship with my mother-in-law is nice because it gives me someone to be there for on Mother's Day, and any other day of the year.

    If you are mum-less, you too should find a deserving woman in your life and celebrate Mother's Day with her. If you don't know anyone, there are plenty of lonely mums in rest homes who would enjoy your company for a couple of hours. The visit will make both of your days, and perhaps your lives, a little bit better.

    Why does time seem to fly by faster as we get old? You've got your aging brain to blame. This is likely due largely to the physical changes of our nerves and neurons (神经元). New research suggests 'rapid fire' abilities of the young brain allow us to process more information during youth, causing the days to seem longer earlier in life. However, as we get old, researchers say the older brain takes more time to process information.

    The new finding put forward by a Duke University researcher was published in a paper in the journal European Review this week According to Adrian Bejan, the J. A Jones Professor of Mechanical Engineering at Duke, the physical changes of our nerves and neurons play, a major role in our perception (知觉) of time as we get old. Over the years these structures become more complex and eventually begin to degrade.

    "Little babies, for example, move their eyes much more often than adults because they're processing images at a faster rate," Beian says, For older people, this means fewer images are being processed in the same amount of time, causing experiences to seem as though they're happening more quickly.

    As a young boy, I knew what people said was not always what they meant or were feeling. And I knew it was possible to get others to do what I wanted if I read their real feelings and responded(回应) suitably to their needs. At the age of eleven, I sold sponge rubber(泡沫橡胶) door-to-door after school and quickly worked out how to tell if someone was likely to buy from me. When I knocked on a door, if someone told me to go away but their hands were open and they showed their palms (the inside surfaces of their hands), I knew it was safe to continue with my presentation(展示) because they weren't angry or threatening although they may have a dismissive(不屑 ) attitude. If someone told me to go away in a soft voice but used a pointed finger or closed hand, I knew it was time to leave.

    As a teenager, I became a pots and pans(炊具)salesperson, and my ability to read people earned me enough money to buy my first house. Selling gave me the chance to meet people and study them close and to know whether they would buy or not, simply by watching their body language.

    I joined the life insurance business at the age of twenty. And I went on to break several sales records for my company, becoming the youngest person to sell over a million dollars' worth of business in my first year. This achievement allowed me to become a member of the well-known Million Dollar Round Table (MDRT, which recognizes the world's top achievers in life insurance). I was lucky that the skills I'd learned as a boy in watching body language while selling pots and pans could be used in this new area, and were directly related to the success I could have in any business closely connected with people.

Every four or five years, vast quantities of warm water build up along the west coast of South America. This phenomenon, El Nino, creates storms that cause destructive floods. The result is costly.

Modern farmers come to terms with El Nino. They use money saved in good years to rebuild in bad ones. But history suggests it need not be like that. In a paper published recently, Ari Caramanica, an archaeologist at University of the Pacific, in Lima, shows how it used to be done. And the answer seems to be, "better".

Dr Caramanica and her colleagues have been studying the Pampa de Mocan, a coastal desert plain in northern Peru. Pampa de Mocan is not suitable for farming. Its soil contains little organic matter and the annual rainfall in non-Nino years is usually less than two centimeters. Today's farmers therefore depend on canals to carry water from local rivers to their fields.

It had been assumed that ancient farmers had a similar arrangement — and so they did. But Dr Caramanica also found eight canals that could carry water far beyond the range of modern farms. She thinks that they were intended to guide the floodwaters arriving during Nino years. Around a quarter of the ancient agricultural infrastructure of this area seems to have been built only for managing Nino-generated floodwaters.

Evidence from pollen supports this theory, revealing that Pampa de Mocan produced lots of crops in some years, while remaining nearly barren in others. The team also uncovered two cisterns in the area serviced by the extended canals. These, probably, were used to store extra flood-water.

These findings suggest that, rather than resisting El Nino, early farmers in Pampa de Mocan were ready to make use of it when it arrived. Modern farmers might do well to learn from them.