I serve as an educator and health care provider as well, therefore, I have worked with numerous children infected with the virus that causes AIDS. The relationships that I have had with these special kids have been gifts in my life. They have taught me so many things, but I have especially learned that great courage can be found in the smallest of packages. Let me tell you about Tyler.

    Tyler was born infected with HIV: his mother was also infected.From the very beginning of his life, he was dependent on medications to enable him to survive.When he was five, he had a tube surgically inserted in a vein in his chest.This tube was connected to a pump, which he carried in a small backpack on his back. Medications were hooked up to this pump and were continuously supplied through this tube to his bloodstream.At times, he also needed supplemented oxygen to support his breathing.

    Tyler wasn't willing to give up one single moment of his childhood to this deadly disease.It was not unusual to find him playing and racing around his backyard, wearing his medicine-laden backpack and dragging his tank of oxygen behind him in his little wagon.All of us who knew Tyler marveled at his pure joy in being alive and the energy it gave him.Tyler's mom often teased him by telling him that he moved so fast that she needed to dress him in red.That way, when she peered through the window to check on him playing in the yard, she could quickly spot him.

    This dreaded disease eventually wore down even the likes of a little dynamo (精力充沛的人) like Tyler. He grew quite ill and, unfortunately, so did his HIV-infected mother.When it became apparent that he wasn't going to survive, Tyler's mom talked to him about death.She comforted him by telling Tyler that she was dying too, and that she would be with him soon in heaven.

    A few days before his death, Tyler beckoned me over to his hospital bed and whispered, “I might die soon.I'm not scared.When I die, please dress me in red.Mom promised she's coming to heaven, too.I'll be playing when she gets there, and I want to make sure she can find me.”

    The year was 1932. Amelia Earhart was flying alone from North America to England in a small single-engined aeroplane. At midnight, several hours after she had left Newfoundland, she ran into bad weather. To make things worse, her altimeter (高度表) failed and she didn't know how high she was flying. At night, and in a storm, a pilot is in great difficulty without an altimeter. At times, her plane nearly plunged (冲) into the sea.

    Just before dawn, there was further trouble. Amelia noticed flames coming from the engine. Would she be able to reach land? There was nothing to do except to keep going and to hope.

    In the end, Amelia Earhart did reach Ireland, and for the courage she had shown, she was warmly welcomed in England and Europe. When she returned to the United States, she was honored by President Hoover at a special dinner in the White House. From that time on, Amelia Earhart was famous.

    What was so important about her flight? Amelia Earhart was the first woman to fly the Atlantic Ocean alone, and she had set a record of fourteen hours and fifty—six minutes.

    In the years that followed, Amelia Earhart made several flights across the United States, and on each occasion (时刻) she set a new record for flying time. Amelia Earhart made these flights to show that women had a place in aviation (航空) and that air travel was useful.

    It's a real case of fish out of water. Blennies (鲇鱼) in the South Pacific Ocean are gradually relocating to land to escape their predators (捕食者), in an example of evolution in action.

    Fish first began crawling onto dry land about 400 million years ago, kicking off an evolutionary chain of events that led to humans. But their reasons for exiting the sea have been uncertain.

    To look for clues, Terry Ord at the University of New South Wales in Australia has been studying several species of blennies at Rarotonga, the largest of the Cook Islands.

    At low tide, blennies are commonly found swimming in rock pools around the edges of the island. But when high tide moves in, they climb up to dry land and move around the rocks until the tide retreats.

    The researchers found that this is most likely to avoid predators that swim in with the rising tide – mainly bigger fish like lionfish.

    To test what would happen if blennies did not have an escape plan, they made blenny models and sank them in the sea. The mimics ended up with wounds, bite marks and chunks-missing.

    Of course, there are still dangers for blennies on land, like the occasional bird attack, but the predation risk on land is a third that of underwater.

    What's more, moving onto land has additional benefits for blennies. Holes in the rocks provide sheltered nests for laying eggs, and they can maintain their diet of bacteria.

    In fact, several species of blenny fish at Rarotonga have already made the full transition to land-dwelling (陆生的) species. They continue to breathe with their gills, but have developed stronger tail fins and jump from rock to rock.

    Ord believes that many evolutionary processes have been driven by the need to escape predators. “It is often assumed that animals move homes to find new sources of food, but in many cases, escaping predators is a stronger motivation.” he says.

The Gift of Life

    Most couples demonstrate their love on February 14 with flowers or chocolates. But these four men and women have offered the ultimate loving gesture—the gift of life. Each sacrifice has enabled their loved ones to live full and active lives again after serious illness.

    I'D Do THE SAME FORHER

    Michele Johnson, 53, has been married to Gay, 57, for 26 years.

    With her husband suffering from a congenital(先天性的)kidney condition, in 2013 Michele  gave him one of him. Gay said: “I needed to be hooked up to a dialysis(透析)machine. I had no quality of life at all. However, I felt great as soon as I woke up after the operation. I told her I'd do the same for her.”

    I LOVE BRENDA TO BITS

    Brenda Green, 62, met her husband Keith, 63, when she was 24 and they married five years later. When Brenda was told five years ago she needed a kidney transplant, she cried. I Ⅱ give you mine.” Keith said without hesitation. “Brenda is my wife and I love her to bits.”

    MY WIFE'S MY HERO

    Stephen Heavyside, 61, and wife Patricia, 62, have been married for 40 years. Stephen said: “I was diagnosed with adult polycystic kidney disease five years ago. Patricia took good care of me and donated a kidney. This has brought us even closer.”

    He said “Patricia's gift changed my life. She is my hero.”

    DECISION WAS EASY

    Anna Stevens, 48, and husband Gary, 53, of Watford, Herts, have been wed for 23 years. Anna donated a kidney to her husband. She said of the transplant: “It was the easiest decision I've ever made.” Gary said. “There's only two words that I can use to describe her:  My angel.”

    Dr Dian Fossey, one of the world's leading women scientists, had a remarkable career. The work she devoted her life to protecting and studying the mountain gorillas (大猩猩) of Africa—has proved highly effective and has resulted in the steady (平稳的) increase of this most endangered great apes.

    Fossey made her first trip to Africa in 1963. Three years later, she returned to Africa to begin a long term study of the mountain gorillas. She set up camp in the Democratic Republic of Congo but moved to Rwanda because of political reasons in 1967. She established her "Karisoke" Research Centre camp on September 24, 1967.

    Fossey's aims were to study gorilla ecology (生态学) and social organization. She found that in order to achieve this, she needed to recognize individual gorillas, which required that the gorillas get used to her presence (出现). By copying gorillas' behaviour and sounds, Fossey began to gain their trust, and in 1970 an adult male gorilla she had named "Peanuts" reached out to touch her hand.

    Close observations over thousands of hours enabled Fossey to gain the gorillas' trust and bring forth new knowledge about their behaviour. Stories and photographs of her work were published in National Geographic Magazine and elsewhere.

    In 1977, one of Fossey's favorite gorillas, Digit, was killed by poachers and she established the Digit Fund to help raise money for gorilla protection efforts in the same year.

    On December 26, 1985, Fossey was murdered while going back to her house in Karisoke. Her body was discovered near the research centre. Most probably? Dian Fossey had been killed by the poachers she'd fought against. On her tombstone (墓碑): "No one loved gorillas more..."

    In 1988, the life and the work of Fossey were made into a movie based on her book.

    University of Pennsylvania researchers say that for the first time they have linked social media use to increases in depression and loneliness. The idea that social media is anything but social when it comes to mental health has been talked about for years, but not many studies have managed to actually link the two. To do that, Penn researchers, led by psychologist Melissa Hunt, designed a study that focused on WeChat, Snapchat and Instagram.

    The study was conducted with 143 participants, who before they began, completed a mood survey and sent along photos of their battery screens, showing how often they were using their phones to access social media. "we set out to do a study which attempts to imitate real life." Hunt said.

    The study divided the participants into two groups: The first group was allowed to maintain their normal social media habits. The other, the control group, was restricted to 10 minutes per day on social media. The restrictions were put in place for three weeks and then tested for now comes such as fear of missing out, anxiety, depression and loneliness.

    The results showed a very clear link between social media use and increased levels of depression and loneliness." Using less social media then you normally do would lead to significant decreases in both depression and loneliness " Hunt said.

    Social media invites what Hunt calls "downward social comparison." "When you're online, it can sometimes seem that everyone else is cooler and having more fun and included in more things and you're left out," Hunt said. And that's just generally discouraging. "Every minute you spend online is a minute you are not doing your work or not meeting a friend for dinner or having a deep conversation with your roommate." And these real life activities are the ones that you can encourage self-esteem and self-worth, Hunt added.

    "People are on their devices, and that's not going to change," she said. But as in life, a bit of control goes a long way.