【推荐2】Scientists believe they could bring the likes of dodos(渡渡鸟)back from the dead through cloning experiments in the near future which could see the flightless birds revived from their extinction.

The big bird, which was about a metre tall and weighed up to 18 kilograms, was native to Mauritius but became extinct in the 1600s, shortly after humans discovered the island. However, 400 years later, scientists now believe that they could bring the dodo back to life through cloning of some of its closest living relatives.

Scientists recently published a paper which identified the overall genomic structure of dinosaurs. The team achieved this by tracing the ancestors (祖先)of birds — the dinosaurs closest living relatives — to create the genomic structure. Researchers involved in the study say it is an emphatic ‘no’ when it comes to the possibility of ever being able to clone dinosaurs, but they do say that more recently extinct birds like the carrier pigeon and the dodo could be brought back due to the fact that they have such close living relatives.

University of Kent scientists Darren Griffin and Rebecca O’Connor wrote in an article for The Conversation: “We discovered that birds and most flightless dinosaurs had a lot of chromosomes (packages of DNA). Having so many allows animals to generate variation, the driver of natural selection.”

“However, though it is a long shot, it may be possible in future to use Jurassic Park technology to help avoid some of the harm that humans have caused. Mankind has seen the extinction of well-known avian dinosaurs such as the dodo and the passenger pigeon.”

“Recovery(恢复)of DNA that is a only few hundred years old from these birds is a far more realistic way. It may also be that eggs from closely related living species might just be good enough. In the right conditions we may be able to use them to resurrect some of these species from extinction.”

If you shower before bed, you’ve probably wondered whether sleeping with damp hair is a problem. Maybe you’ve heard it could make you sick, or that it can damage your hair or skin.

What’s the truth? Let’s address the “it can make you sick” myth first. “    1    ” says Dr. William Schaffner, a professor of medicine. While this idea persists, Schaffner says it was long ago disproved. It’s true that you’re much more likely to catch a common cold during the winter months. But this has to do with the ways respiratory (呼吸的) viruses spread, he says.

    2     Illness-causing bacteria and viruses don’t appear naturally, and so you’re not going to make yourself ill by getting your pillow a little damp at night, Schaffner says. But there is a possible exception. Some research has shown that pillows—especially those made with synthetic materials—can contain asthma- or allergy-triggering molds (哮喘或致敏菌) and fungus, which tend to do well in damp environments, and so do dust mites, says Dr. Payel Gupta, a spokesperson for the American Lung Association.

Gupta says there’s no evidence that people who sleep with wet hair experience more allergy or asthma symptoms.     3     But if you wake up with a stuffy nose, itchy or watery eyes, breathing problems or other allergy or asthma symptoms—or even if you don’t—you should wash your pillow cases and sheets in hot water at least once a week to reduce your exposure to any potential irritants (刺激物).

When it comes to the health of your hair and skin, there may be a few other reasons to worry about wet hair. “Generally, it’s thought not to be good for hair to sleep with it wet,” says Dr. George Cotsarelis, a professor of dermatology (皮肤病学), “    4    ”

It’s also worth noting that almost anything you do to your hair—from brushing and blow-drying it to coloring it or exposing it to the sun—can damage it.

【推荐1】Some dinosaurs grew slowly and steadily. Others experienced a growth spurt as they neared adulthood. A “growth spurt” is when something or someone grows very quickly. For example, children usually have a growth spurt between the ages of 12 and 18. The same appears to be true for some dinosaurs! To reach their findings, scientists cut through the fossilized bones of dinosaurs. They examined the yearly growth rings of the bones from 11 kinds of theropods collected from their legs. Theropods are a group of dinosaurs that mainly walked on two legs and include big meat-eating dinosaurs, like tyrannosaurus rex, commonly known as T. rex.

The research team looked at fossils from museums in the United States, Canada, China, and Argentina. They were able to cut into the fossilized bones of one of the world's most famous T. rexes, known as Sue. These bones showed that the T. rex and its relatives have a period of extreme growth during the years before adulthood. It also shows that they reached full adult size by around age 20. Sue is about 13 meters tall. She is believed to have lived to about 33 years. But not all the large theropods had more steady rates of growth over a longer period of time. The Argentinian dinosaur did not reach its full adult size until it reached about 40 years of age. It is believed to have lived to about age 50.

Big theropods share the same basic body design. They walked on two legs and had large skulls and strong jaws. And of course, they had threatening teeth.

The lead researcher on the study is Tom Cullen. He is a paleontologist with the North Carolina Museum of Natural Sciences and North Carolina State University. He said that before this study, “it was known that T. rex grew very quickly, but it was not clear if all theropod dinosaurs reached giant size in the same way, or if there were many ways they grew so big.”

【推荐2】A new study, published this week in the journal Frontiers in Veterinary Science, reveals that non-human animals’ tears are not so different from our own. The chemical similarities are so great, in fact, that the composition of other species’ tears—and how they’re adapted to their environments—may provide insights into better treatments for human eye disease.

Previously, scientists had studied closely only the tears of a handful of mammals, including humans, dogs, horses, camels, and monkeys. In the new study, Brazilian veterinarians analyzed the tears of reptiles and birds for the first time, focusing on seven species.

Tears, which are released from tear tubes, form a film over the eye that’s composed of three ingredients: mucus, water and oil. The mucus coats the eye’s surface and helps to attach the film to the eye, the water is a natural salty solution containing crucial proteins and minerals, and the oil prevents the eye from drying out.

Humans are the only known species to produce emotional tears; the expression “crocodile tears”, which refers to a person’s phony display of emotion, comes from the mysterious tendency of crocodiles to release tears as they eat.

But tears play key roles beyond weeping, notes Lionel Sebbag at Iowa State University, who was not involved in the new research. They help with vision by lubricating(润滑)and clearing the eye. They also protect the eye against infection and provide nutrition to the cornea, the eye’s clear outer layer, which lacks blood tubes, he says.

Learning how reptiles and birds’ use tears may also inspire new medications for conditions such as dry eye, which occurs when tear tubes don’t produce enough oil. The disease, common in cats, dogs and people, can sometimes lead to blindness.

【推荐3】Though not as much as in the past, grandparents are the teachers of the Navajo (纳瓦霍人) youth. They make young people aware of life at an early age. The parents allow them the privilege of teaching the children, and the grandparents take great pride in raising them.

Young children often stay with their grandparents for years at a time, developing a close and trusting relationship. The grandparents teach them Navajo legends and the principle of life, emphasizing both new culture trends and the preservation of traditions.

The grandparents are also the leading figure in teaching the youth the arts of weaving, caring for the live stock, using herbal medicine, and other arts and crafts.

The children are taught to respect their elders, care for them, help them and learn from them. Young people are urged to listen with care to the words of their elders and keep as much wisdom as possible. Grandparents often go to social gatherings and traditional events, and young people have opportunities to learn more about their culture and traditions.

I lived with my grandmother for thirteen years, and she raised me in the old ways of our people. Although I was going to school, she taught me as much as she could about our traditions. If I had a chance, I would listen again to her wise teachings, expressed with kindness in a soft voice that touched my heart.

We used to plant corn and pumpkin every summer. They never grew big enough to feed us, but we planted them anyway. I asked my grandmother why. She said, “Grandson, our plants will be far more beautiful than the flowers outside the fence.” I didn’t understand until one day I saw their beauty as I was coming over the hill with her. She said, “Anything that is a part of you is always far more beautiful than the things which you pass by.” We had some beautiful years together. I’m glad she is a part of me and I’m apart of her.

Children used to be well disciplined, possessing more respect for culture, traditions and beliefs than they do now. The world of the Navajo has been influenced by the western world, and the grandparents have less control and influence than they used to. But the young people who have been touched by their teachings have glimpsed a way of life beyond what most people know today.