"Over the years the unthinkable hasbecome thinkable and today we sense we are close to being able to alter humanheredity œ#)." These were the words of David Baltimore of the CaliforniaInstitute of Technology, on December 1st, when he opened a three-day meeting inWashington to discuss the morality and use of human gene editing. Dr Baltimoreis an old hand at these sorts of discussions, for he was also a participant inthe Asilomar conference, in 1975, which brought scientists together to discussa safe way of using the then-new tcchnology of recombinant DNA, and whoserecommendations influenced a generation of biotechnology researchers.

Four decades on, the need for a similarsort of chin-wag has arisen. The InternationalSummit on Human Gene Editing has been held by the national scientific academiesof three countries — America, Britain and China. They are particularlyconcerned about whether gene editing should be used to make heritable changesto the human germ line, something Dr Baltimore described as a deep andtroubling question. Like those of Asilomar, the conclusions of this meetingwill not be binding. But the hope is that, again like Asilomar, a mixture ofcommon sense and peer pressure will create a world in which scientists aretrusted to regulate themselves, rather than having politicians and civilservants do it for them. The meeting is being held against a backdrop of rapidscientific advance, Since 2012 research into a new, easy-to-use editing tool calledCRISPR-Cas9 has blossomed. This technique involves a piece of RNA (a chemicalmessenger, which can be used to recognise a target section of DNA) and anenzyme (酶)called a nuclease that can snip unwanted genes out and paste new ones in.

Public interest was aroused in April,when Chinese scientists announced they had edited genes in non-viable ( 无活力的) humanembryos, and again in November when British researchers said they hadsuccessfully treated a one-year-old girl who had leukaemia ( 白血病),using gene-edited T-cells. T-cells are part of the immune system that attack,among other things, tumour cells. The researchers altered T-cells from ahealthy donor to encourage them to recognise and kill the patient's cancer, tomake them immune to her leukaemia drug, and to ensure they did not attack herhealthy cells.

In another recent development, a firmcalled Edit as Medicine, which is based in Cambridge, Massachusetts, has saidit hopes, in 2017, to start human clinical trials of CRISPR-Cas9 as a treatmentfor a rare genetic form of blindness known as Leber congenital amaurosis (伯氏先天性黑蒙).Though other companies are already testing gene-editing therapies, these employolder, clunkier forms of the technology that seem likely to have lesscommercial potential. Moreover, researchers at the Broad Institute, also inCambridge, said this week that they had made changes to CRISPR-Cas9 whichgreatly reduce the rate of editing errors — one of the main obstacles to thetechnique's medical use.

On the subject of germ-line editing,Eric Lander, the Broad's head, told the meeting it would be useful only in rarecases and said it might be a good idea to "exercise caution? before makingpermanent changes to the gene pool. The need for caution is advice that mightalso be heeded by those pursuing work in animals other than people, and inplants — subjects not being covered by the summit.

    Not every parent looks forward to the day when their child goes off to school. In fact some parents are not sending their children to school at all. Instead they are choosing to teach their children at home. This is called homeschooling. Parents, caregivers, or private tutors educate children individually at home instead of sending them off to be formally educated in public or private schools. In the U.S. only about three percent of children are homeschooled.

    There are many reasons why some parents choose to homeschool. One reason is that some parents do not feel their children are safe in school because of bullying (恃强凌弱). It is said that bullying is very common in the school. Other parents want their children's education to be based on their religion or moral beliefs. Yet other parents think the education in school is not good enough. Homeschooling is also seen as a choice for families that live in rural areas, and families that move frequently.

    There are many different ways to homeschool, and homeschooling allows parents to design lessons based on their children's needs. Families can purchase textbooks to use or create their own materials. Some parents follow a philosophy called unschooling, which allows a child to determine when and how they want to learn based on their natural ability. Some worry that homeschooling means students won't have opportunities to communicate with others.

    To solve this problem, some families have created activities, where a group of homeschooled students will learn and play together and participate in activities that would normally happen in school like field trips.

    Besides, being homeschooled doesn't mean a student cannot go to college. Most colleges accept homeschooled students. And the homeschooled students can get the same degrees, too.

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    My mom only had one eye. I hated her... she was such an embarrassment. My mom ran a small shop at a flea market. She collected little weeds and such to sell... anything for the money we needed she was such an embarrassment. There was this one day during elementary school.

I remember that it was field day, and my mom came. I was so embarrassed. How could she do this to me? I threw her a hateful look and ran out. The next day at school... "Your mom only has one eye?!" and they taunted me.

I wished that my mom would just disappear from this world so I said to my mom. "Why don't you just die?" My mom did not respond. I guess I felt a little bad, but at the same time, it felt good to think that I had said what I'd wanted to say all this time. Maybe it was because my mom hadn't punished me, but I didn't think that I had hurt her feelings very badly.

    That night... I woke up, and went to the kitchen to get a glass of water. My mom was crying there, so quietly, as if she was afraid that she might wake me. I hated my mother who was crying out of her one eye. So I told myself that I would grow up and become successful, because I hated my one-eyed mom and our desperate poverty.

Then I studied really hard. I left my mother and came to Seoul and studied, and got accepted in the Seoul University with all the confidence I had. Then, I got married. I bought a house of my own. Then I had kids, too. Now I'm living happily as a successful man. I like it here because it's a place that doesn't remind me of my mom.

This happiness was getting bigger and bigger, when someone unexpected came to see me "What?! Who's this?!" It was my mother... Still wither one eye. It felt as if the whole sky was falling apart on me. My little girl ran away, scared of my mom's eye.

And I asked her, "Who are you? I don't know you!!" as if I tried to make that real. I screamed at her "How dare you come to my house and scare my daughter! Get out of here now!!" And to this, my mother quietly answered, "oh, I'm so sorry. I may have gotten the wrong address," and she disappeared. Thank goodness... she doesn't recognize me. I was quite relieved. I told myself that I wasn't going to care, or think about this for the rest of my life.

    Then a wave of relief came upon me... one day, a letter regarding a school reunion came to my house. I lied to my wife saying that I was going on a business trip. After the reunion, I went down to the old shack, that I used to call a house, just out of curiosity there, I found my mother fallen on the cold ground. She had a piece of paper in her hand. It was a letter to me.

She wrote:

My son, I think my life has been long enough now. For you... I'm sorry that I only have one eye, and I was an embarrassment for you. You see, when you were very little, you got into an accident, and lost your eye. As a mother, I couldn't stand watching you having to grow up with only one eye… so I gave you mine... I was so proud of my son that was seeing a whole new world for me, in my place, with that eye. I was never upset at you for anything you did. The couple times that you were angry with me I thought to myself, ‘it's because he loves me.' I miss you so much. I love you. You mean the world to me. So I gave you mine. With all my love to you! Your mom.

My World Shattered. I hated the person who only lived for me. I cried for My Mother, I didn't know of any way that will make up for my worst deeds...

    I came to study in the United States a year ago .Yet I did not know the real American society until I was injured in a car accident because after the accident I had to see a doctor and go to court.

    After the accident, my roommate called a doctor for me. I was very grateful and determined to repay him one day. But the next day, he asked me to pay him $200 for what he had done. I was astonished. He had good reason to charge me, he said. And if I wanted to collect money from the person who was responsible for my injury, I'd have to have a good lawyer. And only a good doctor can help me get a good lawyer .Now that he had helped me find a good doctor, it was only fair that I should pay him.

    But every day I went to see the doctor, I had to wait about 50 minutes. He would see two or three patients at the same time, and often stop treating one so as to see another. Yet he charged me $115 each time .The final examination report consisted of ten lines, and it cost me $215.

    My lawyer was all smiles the first time we met. But after that he avoided seeing me at all. He knew very well the other party was responsible for the accident, yet he hardly did anything. He simply waited to collect his money. He was so irresponsible that I decided to dismiss him. And he made me pay him $770.

    Now I had to act as my own lawyer. Due to my inexperience, I told the insurance company the date I was leaving America. Knowing that, they played for time...and I left without getting a cent.

    It has been found that plastic that finds itself into UK's waters can find its way to the Arctic within just two years. UK researchers have used a current-tracking tool to follow the waste as it was carried by the waters of the northern hemisphere.

    The team at Imperial College London used PlasticAdrift.org to track ocean currents(洋流) and follow the trail of plastic north to the freezing Arctic waters. Their study revealed that the majority of plastic waste which didn't end up on the UK's coastline, or sink to the ocean floor, was carried through the Barents Sea, north of Norway, before being carried into the Arctic Ocean.

    Large pockets of the world's oceans are now choked with a soup of discarded plastics, made up of everything from shopping bags to old children's toys, brought to these trash “islands” by the currents. Over time larger chunks (厚块，大块) are broken down by the sun's ultraviolet rays (紫外线) and the saltwater, leaving plenty of micro plastics which can kill fish and other wildlife.

    Dr. Erik Van Sebille, a lecturer in oceanography (海洋学) and climate change at Imperial, said, “We're only just beginning to understand the effect that plastic waste has on the weak Arctic ecosystem(生态系统), but we know enough about the damage done by oceanic plastic pollution to act and reduce its impact on our oceans and coastlines. From seabirds caught in loops of plastic packaging to polystyrene particles(聚苯乙烯粒子) blocking the digestive(消化的) systems of fish, plastic causes a continuous path of destruction from surface to seafloor. This analysis shows how in the UK we're part of the problem.”

    Dr. Erik continued, “It would be impossible to ban plastic, and undesirable as it is, it's a useful material that offers many benefits. We should instead have a holistic (整体的) approach to improving the situation, including social and behavioral, chemical and engineering solutions. Our aim is to have the least amount of plastic that ends up in the oceans and make sure it degrades (降解) quickly and safely if it does. ”

    A new high tech mirror, designed specifically for cancer patients, will only become reflective when a user smiles into it. The plug-in device, which exactly looks like a tablet, comes equipped with a mirror, a built-in camera, and a smart material triggered(触发)by some software. Facial recognition technology captures the face and instructs the surface of the mirror to change when a smile is detected. It can hang on a wall or sit on a table, much like a conventional mirror. Unlike a regular mirror, however, the price is currently standing at a surprising $2000—$3000.

    After witnessing a close family member struggle through cancer treatments, Turkish industrial designer Berk Ilhan decided to focus his work primarily on products that would cultivate joy and benefit cancer patients directly.

    “She told me in the first days after her diagnosis, it was difficult for her to look in the mirror and acknowledge she had cancer.” he said.“ Our facial expressions affect how we feel. If we flex(绷紧)our facial muscles to smile, our brains think that something good happened and as a result, we feel happiness.”

    After earning his master's degree at the School of Visual Arts in New York, Ilhan spent several weeks visiting cancer hospitals in Turkey, speaking to both patients and doctors. He spent two years designing and developing the mirror. The idea behind it is that smiling, even when forced, can make us feel better, according to research known as the facial feedback hypothesis. Laughter is linked to improved immune system function, and some researchers claim it can even increase our lifespans.

Ilhan is currently producing the mirror in limited quantities at the previously mentioned price. The product, however, will soon be launching a campaign in which Ilhan hopes to raise enough funds to bring the price down to $500.He also intends to donate the mirror to hospitals when it is financially possible to do so.