Nuclear power's danger to health, safety, and even life itself can be summed up in one word: radiation.

    Nuclear radiation has a certain mystery about it, partly because it cannot be detected by human senses. It can't be seen or heard, or touched or tasted, even though it may be all around us. There are other things like that. For example, radio waves are all around us but we can't detect them, sense them, without a radio receiver. Similarly, we can't sense radioactivity without a radiation detector. But unlike common radio waves, nuclear radiation is not harmless to human beings and other living things.

    At very high levels, radiation can kill an animal or human being immediately by killing masses of cells in vital organs. But even the lowest levels can do serious damage. There is no levels of radiation that is completely safe. If the radiation does not hit anything important, the damage may not be serious. This is the case when only a few cells are hit, and if they are killed immediately. Your body will replace the dead cells with healthy ones. But if the few cells are only damaged, and if they reproduce themselves, you may be in trouble. They can grow into cancer. Sometimes this does not show up for many years.

    This is another reason for some of the mystery about nuclear radiation. Serious damage can be done without the victim being aware at the time that damage has occurred. A person can be irradiated(辐射)and feel fine, then die for cancer five, ten, or twenty years later as a result. Or a child can be born weak as a result of radiation absorbed by its grandparents.

    Radiation can hurt us. We must know the truth.

    What do you usually do to comfort your friends when they are sad? You probably pat them on the shoulder, or give them a warm hug.

    We used to think that knowing when and how to comfort others was an ability that only humans have. But scientists have discovered that apes (猩猩) have this ability too.

    Two researchers from Emory University in Atlanta, US, went to an Ape Protection Centre in Congo to study bonobos (倭黑猩猩), which are closely related to humans.

    The researchers analyzed the bonobos' reactions (反应) after more than 370 cases of stressful situations, such as fights and losing temper, and found that some bonobos rushed to hug those that were screaming after being attacked, just like humans would have done.

    However, researchers found that not all bonobos were able to comfort others. In the protection center, many bonobos are orphans whose mothers were killed by hunters. They were found to be more worried in times of tension and have greater difficulty controlling their own emotions, making them worse at reaching out to help friends in need.

    "Orphans, who have not had the benefit of a mother helping them handling their emotions, are much worse at comforting others," Professor Frans de Waal told TheTelegraph. "Bonobos with moms were able to curb their negative emotional reactions more quickly. Therefore, they pay more attention to others."

    This pattern mirrors the way that human children have been found to react. Those who are good at handling their own emotions—for example, those who can calm themselves down more quickly after upsetting experiences—are usually better at expressing their concerns for others.

    PTSD(战后创伤) is sadly a common affliction(折磨) for many soldiers who have witnessed conflict, an invisible wound that continues to cause incredible suffering long after the guns have fallen silent.

    "A lot of us come home without realizing we are bringing the war home with us," said Josh Marino, a veteran (退伍兵)of the Iraq war who suffered the effects of PTSD of suicide .

    "I didn't want to deal with it anymore," Marino said. He wrote a goodbye note, grabbed a knife and went outside for a final cigarette in the rain. But then, from the deepest depth of despair came hope. Meowing out of the bushes next to him came a stray black and white kitten (小猫) which, according to Marino, "just walked up and started rubbing up against my leg and let me pet him. I came to life again and I broke down crying. I burst into tears."

    From this accidental encounter everything changed. Marino found a new purpose in life through the friendly cat, who he named Scout, and who he credits with saving his life. "I stopped thinking about all my problems, and started thinking about all his problems, and what I could do to help him, "Marino said. The bond between them was instant，but that wasn't the end of the story.

    Marino has made a video of his and Scout's remarkable story of healing and heartbreak which you can watch on the Internet. The story is dedicated to showing how animals can help humans through tough times, as well as humans can help them. It is a beautiful story that is sure to tug at your heart strings, showing just how powerful the bond between humans and animals can be. We love it, and we hope you do too!

    If you think can-do, and you're creative and persistent, it's amazing what you can accomplish. During college, I remember being told that to fulfill my language requirement, I would "have to" take a class that I had no interest in and was meaningless to me. Instead of taking this class, however, I decided to create my own. So I put together a list of books I would read and the assignments I would do and found a teacher to sponsor me. I then went to the dean of the school and presented my case. He bought into my idea and I completed my language requirement by taking my self-built course.

    American aviator Elinor Smith once said, "It has long since come to my attention that people of accomplishment rarely sat back and let things happen to them. They went out and happened to things."

    It's so true. To reach your goals in life, you must seize the initiative. If you're feeling bad about not being asked out on dates, don't just sit around and sulk, do something about it. Find ways to meet people. Be friendly and try smiling a lot. Ask them out. They may not know how great you are.

    Don't wait for that perfect job to fall in your lap, go after it. Send out your resume, network, volunteer to work for free.

    If you're at a store and need assistance, don't wait for the salesperson to find you, you find them.

    Some people mistake can-do for being pushy, aggressive, or obnoxious. Wrong. Can-do is courageous, persistent, and smart. Others think can-do people stretch the rules and make their own laws. Not so. Can-do thinkers are creative, enterprising, and extremely resourceful.

    George Bernard Shaw, the English playwright, knew all about can-do. Listen to how he said it: "People are always blaming their circumstances for what they are. I don't believe in circumstances. The people who get on in this world are the people who get up and look for the circumstances they want, and if they can't find them, make them."

    It started during a yoga class. She felt a strange pull on her neck, a feeling completely foreign to her. Her friend suggested she rush to the emergency room. It turned out that she was having a heart attack.

    She didn't share similar symptoms with someone who was likely to have a heart attack. She exercised, watched her plate and did not smoke. But on reviewing her medical history, I found that her cholesterol (胆固醇) level was sky-high. She had been prescribed a cholesterol-lowering statin (他汀) medication, but she never picked up the prescription because of the scary things she had read about statins on the Internet. She was the victim of fake medical news.

    While misinformation has been the object of great attention in politics, medical misinformation might lead to an increase in deaths. As is true with fake news in general, medical lies tend to spread further than truths on the Internet—and they have very real bad consequences.

    False medical information can also lead to patients experiencing greater side effects through the "nocebo effect (反安慰剂效应) ". Sometimes patients benefit from an intervention (干预) simply because they believe they will—that's the placebo effect (安慰剂效应). The nocebo effect is the opposite. Patients can experience harmful effects because they anticipate them. This is very true of statins. In blinded trials, patients who get statins are no more likely to report feeling muscle aches than patients who get a placebo. Yet, in clinical practice, according to one study, almost a fifth of patients taking statins report side effects, leading many to discontinue the drugs.

    What else is on the fake news hit list? As always, vaccines (疫苗) . False concerns that the vaccine may cause side effects have greatly reduced coverage rates.

    Cancer is another big target for pushers of medical misinformation—many of whom refuse alternative therapies. "Though most people think cancer tumors are bad, they're actually the way your body attempts to contain the harmful cells," one fake news story reads. It warns that prescription medications lead to the uncontrolled cell mutations (变异) .

    Silicon Valley needs to face this problem. I am not a free-speech lawyer, but when human health is at risk, perhaps search engines, social media platforms and websites should be held responsible for promoting or hosting fake information. Meanwhile, journalists should do a better job of spreading accurate information.

Do you want to learn the material you're studying—like, reallylearn it? {#blank#}1{#/blank#}One learning theory suggests that if you overlearn, you'll gain the ability to do something without having to think about it — and eventually obtain more knowledge. Here's what overlearning is and how to do it.

What is overlearning?

Simply put, overlearning means studying something even once you're sure you know it. Don't stop reviewing or studying just because you succeeded in memorizing something. {#blank#}2{#/blank#}

The purpose of overlearning is to make the task easy to ensure it is completed to a high standard with no stress. For example, a student wants to pass their spelling test which has 10 words. Knowing about overlearning, she doesn't just memorize each word, but also learns about the origins of each word. {#blank#}3{#/blank#} Similarly, a teacher wanting to learn about teaching strategies might not simply read one book — they may read ten books, watch videos, attend lectures (and maybe even write their own book).

How do you overlearn?

{#blank#}4{#/blank#} For instance, when using the Leitner method, always review all the flashcards you're assigned on a particular day, even if you feel like passing over them because you got them right last time. Repeatedly going over material you know well is the key to overlearning and eventual automatic recall.

Schedule blocks of time in your week for reviewing materials you've already mastered. {#blank#}5{#/blank#} Continually reintroducing familiar ideas to yourself will dig them deeper into your long term memory.