My folks bought their first house in the early 1940s after Dad got a better job in Marquette, Michigan. We lived just inside the city limits in what was still a rural area.

    In the spring of 1948, when I was 6 years old, my parents bought a calf（小牛）to replace our cow, which had been killed the year before. So one day we drove to a local farm and returned with a white and brown calf we named Tubby.

    We didn't own a truck, so Tubby rode home in the backseat of Dad's car with my 9-year-old brother, Steve, and me. As you can imagine, the trip was a lot of fun for us kids.

    Later that summer, Mom thought it would be cute to take a picture of me sitting on Tubby's back. All went well until the snap of the camera shutter sent Tubby charging off on a run, with me holding on for dear life.

    I lasted for about 30 feet before I hit the ground. Mom was quick enough to shoot a follow-up picture, so we had photos of me both on and off Tubby!

    When summer had passed, the day arrived for poor Tubby to fill our freezer. I must have been somewhere else with my Mom on the fateful day, because I have no memory of how it happened. All I knew was that the barn was empty, and that we had plenty of meat for dinners.

    I hadn't lived on a farm like my mother, so I didn't understand that what happened to Tubby was not unusual. Livestock aren't meant to be pets, and most farm kids know and accept that truth.

    Whenever we had beef for dinner, I would tearfully, “Is this Tubby?” This went on for a couple of weeks until Dad had finally had enough and declared, “No more cows!” That made me feel a little better about poor Tubby.

    At the age of seven, while his friends were spending their allowances on things like candy and toys, Jose Adolfo Quisocola was busy saving money for basic purchases. To try to get his peers（同龄人） to do the same, the boy from Peru came up with the idea of an eco-bank, the Bartselana

    Student Bank, which allows kids of all ages to become financially independent while also helping the environment.

    Set up in 2012, the bank is the world's first bank for kids. To become a member, a kid has to bring in at least 5 kilograms of solid waste and set a savings goal. Once accepted, all bank “partners” are required to deposit at least one additional kilogram of recyclables on a monthly basis and observe other requirements, such as attending financial education and environmental management workshops.

    The waste accumulated is sold to local recycling companies, who, thanks to Jose's efforts, pay a higher-than-market rate for everything brought in by the bank members. The money received is placed in the personal account where they collect until the savings goal is reached. The account holder can then withdraw the money, or choose to leave it and continue to grow for a bigger target. “At the beginning, my teachers thought I was crazy or that a child could not undertake this type of project,” Jose recalls, “They did not understand that we are not the future of the country but its present. Luckily, I had the support of the school headmaster and an assistant in my class.”

    The boy's efforts paid off, and by 2013, the bank had over 200 members, who brought in one ton of recyclable waste. Today, the eco-bank, which now has the support of several local institutions, boasts ten educational centers. They are designed to teach the over 3,000 students, aged 10 to 18, to become financially independent, use their money wisely, and help the environment.

    Not surprisingly, Jose's efforts have earned him several national and international awards. On November 20, 2018, Jose won Children's Climate Prize, which comes with a medal and $5,500 in prize money and is given to a child or youth who has accomplished an extraordinary achievement for the climate or environment.

    Three years ago I worked for a few weeks as a doctor in a new dental clinic(牙科诊所）at Victor Harbor to the south of Adelaide and an hour further away than my usual workplace. My first day there was a driving to a new clinic and getting used to the clinical environment.

    As it was all new to me, I took off my rings: my wedding ring, and one that was an anniversary(周年纪念日)gift from my husband. I put them in a tissue(纸巾)and placed them beside my computer. During my lunch break, I noticed the tissue and thought that it did not look very clean and threw it into the rubbish bin. I went about my work and my day went well; I met new patients and felt that I had been productive

    Driving home at the end of the day, just moments before I reach that were missing. I felt the heat in my body rise, my cheeks(脸颊)burning red. I felt sick to my stomach.

    I spat an hour or so making calls, trying to find my rings. The first people I called were and clinical leader and they gave me a few phone numbers for cleaners I got in touch with already who managed the leaning services for the clinic, and she told me that the bins had already been collected.

    I knew nothing could be done now. I had lost my rings. Bu after two or so hours, I received the most amazing phone cal. The cleaner had gone through the bins and found my rings! I was so thankful to her, someone who had taken the trouble to go through the bins-which is not a pleasant task-to find my priceless rings.

    I worked at that clinic the following day, so I bought chocolates to thank this wonderful person. Unfortunately I did not get to meet her as she was not at work that day.

    Should Parents Teach Children How to Tweet?

    Social media is a seemingly endless source of concern for parents, with worries that it weakens their children's confidence and attention spans. But others counter that it could also be broadening their horizons.

    The latest round of worry was sparked by a study of the impact of social media use on 8-12- year-olds published by Anne Longfield, Children's Commissioner for England. The report focused on 32 children, who said they used social media to stay connected with friends and family and to have fun, by watching videos for example. But they also described pressures from constant contact, online comments that weaken their self-esteem, and the need to shape offline activities to make them shareable. "You see your friends going ice skating, partying or talking about how much revision they have done, and it can make you feel inadequate," says Bea, a junior school student from Bristol, UK. "It's just so hard to get away from."

    Children have to take risks on their journeys to adulthood, and desires to fit in and be popular existed before Mark Zuckerberg came along with Facebook. However, in previous generations these pressures came largely from people they knew, and they mostly stayed outside the home. Now the pressures could come from any one of the nearly 3 billion people online, and follow them from school to home, and can even continue through the night.

    The pressures do get on parents' nerves, among which the utmost concern is how their children can be protected from harms, given that social media is now integral to the way many young people interact. A good starting point is a basic understanding of childhood development milestones.

    Broadly, children have a high dependency on carers for security and guidance up to the age of 5, increasing independence and self-care from 6 to 11, and increasing autonomy and growing reliance on peers from 12-18 years old. Against this background, the suitability of social media for children of different ages should be considered respectively.

    According to Longfield's study, children should be taught about online safety from an early age, better before secondary school. There is growing evidence that efforts need to be extended to provide earlier guidance on less extreme but more common risks, including oversharing, low selfesteem, addiction and insomnia. The evidence suggests she is right. However, approaches that focus merely on the potential negatives are unlikely to work.

    "My school has tried to do a lot, but it often involves trying to drill into us how bad social media can be," says Bea. "People of my age really like social media, so I think a better approach would be if they said ‘Although it is good, here are some negatives'."

    Why elephants rarely get cancer is a mystery that has confused scientists for decades. A study was led by researchers at Huntsman Cancer Institute (HCI) at the University of Utah and Arizona State University, including researchers from the Ringling Bros. Center for Elephant Conservation may have found the answer. According to the results, elephants have 38 additional modified copies of a gene (基因) that encodes p53, a well-defined tumor (肿瘤) suppressor, as compared to humans, who have only two. Further, elephants may have a more powerful mechanism for killing damaged cells that are at risk for becoming cancerous. In isolated elephant cells, this activity is doubled compared to healthy human cells, and five times that of cells from patients with Li-Fraumeni Syndrome, who have only one working copy of p53 and more than a 90 percent lifetime cancer risk in children and adults. The results suggest extra p53 could explain elephants' increased resistance to cancer.

    "Nature has already figured out how to prevent cancer. It's up to us to learn how different animals overcome the problem so we can adapt those strategies to prevent cancer in people," says co-senior author Joshua Schiffman, M.D., pediatric oncologist (肿瘤学家) at Huntsman Cancer Institute, University of Utah School of Medicine, and Primary Children's Hospital.

    According to Schiffman, elephants have long been considered a walking problem. Because they have 100 times as many cells as people, they should be 100 times more likely to have a cell slip into a cancerous state and cause the disease over their long life span of 50 to 70 years. And yet it's believed that elephants get cancer less often, a theory confirmed in this study. Analysis of a large database of elephant deaths estimates a cancer death rate of less than 5 percent compared to 11 to 25 percent in people.

    (The New York Times, Oct.7) The 2019 Nobel Prize in physiology(生理学) or medicine was jointly awarded to three scientists — William G. Kaelin Jr., Peter J. Ratcliffe and Gregg L. Semenza — for their work on how cells sense and adapt to oxygen availability. The Nobel Assembly announced the prize at the Karolinska Institute in Stockholm on Monday.

    Their work established the genetic mechanisms(机制) that allow cells to respond to changes in oxygen levels. The findings have implications(启示) for treating a variety of diseases.

    Why did they win?

    "Oxygen is the lifeblood of living organisms(生物体)," said Dr. George Daley, dean of Harvard Medical School. "Without oxygen, cells can't survive." But too much or too little oxygen can be deadly. The three researchers tried to answer this question: How do cells regulate their responses?

    The investigators uncovered detailed genetic responses to changing oxygen levels that allow cells in the bodies of humans and other animals to sense and respond to fluctuations(波动), increasing and decreasing how much oxygen they receive.

    Why is the work important?

    The discoveries reveal the cellular mechanisms that control such things as adaptation to high altitudes and how cancer cells manage to hijack(攫取) oxygen. Randall Johnson, a member of the Nobel Assembly, described the work as a "textbook discovery" and said it would be something students would start learning at the most basic levels of biology education.

    "This is a basic aspect of how a cell works, and I think from that standpoint alone it's a very exciting thing." Johnson said.

    The research also has implications for treating various diseases in which oxygen is in short supply — including anemia, heart attacks and strokes — as well as for treatment of cancers that are fed by and seek out oxygen.