A new study suggests that washing dishes by hand is healthier than using a dishwasher.

    Nobody likes doing the dishes, but it turns out that doing this task might pay off in an unexpected way. According to a new study published in the Journal of Pediatrics, washing dishes by hand instead of using a dishwasher might prevent the development of allergies (过敏).

    Researchers in Sweden surveyed the parents of 1,029 children aged 7 and 8. They discovered that children whose families hand-washed the dishes instead of using a machine were less likely to have allergies.

    Earlier research has shown that dishes washed by machine are cleaner than those washed by hand. So why would kids who eat with slightly dirtier plates be better when it comes to preventing allergies? One explanation is based on a theory known as the “hygiene hypothesis,” which says the reason why kids develop allergies is that their environment is actually too clean. Your immune system keeps you healthy by fighting germs like viruses and bacteria. But when you have allergies, it overreacts and tries to fight ordinary things like pollen(花粉) or certain foods.

    Being exposed to germs, especially early in life is good training for the immune system, says the lead author of the study, Dr. Bill Hesselmar of Queen Silvia Hospital in Sweden. “You stimulate the immune system in various ways and it becomes tolerant.”

    This study shows that while using the dishwasher might be easier, the old-fashioned method of cleaning up could be better for your health.

    "Some secrets are hidden from health," wrote John Updike in his poem "Fever".

    I have experienced the truth of Updike's observation. My excellent health kept me from seeing some things—things that became secrets of sort.

    One relates to my son Chris. When I lost my health in March, I discovered something I had missed about him.

    Christopher has been a scholar and athlete through high school. He has behaved responsibly, engaged in community service. He has had an impressive peer group of serious students.

    While I saw these things, I had missed before what I experienced while in hospital. Early on, Christopher offered the clearest and most forceful words about my need to be positive and to fight acute leukemia(急性白血病). He never left the room after a visit without making me promise that I would be mentally tough and positive.

    During the first week, he showed his own mental toughness, researching leukemia and learning what the chances were. He even stopped my doctor outside the room, introduced himself and asked directly what he thought of my chances. He processed the answer without overreaction.

    Christopher did admonish(劝告) me against my choice of words the first week at home. I had moved back into my room from weighing myself, discovering a thin figure I did not know. I announced to him and my wife, “dead man walking”. I thought it was a way to lighten the obvious. He saw it as negativity and was strongly against such thinking and talking.

    When I resisted taking medicine sometimes, Christopher formed a “good-cop-bad-cop” team with his mother. Betsy gently and patiently encouraged. He directly and forcefully insisted. He always made the logical arguments for why I needed to take some awful pills.

    My health had hidden something from me; my ill-health helped me to see it.

    Most people agree that honesty is a good thing. But does Mother Nature agree? Animals can't talk, but can they lie in other ways? Can they lie with their bodies and behavior? Animal experts may not call it lying, but they do agree that many animals, from birds to chimpanzees, behave dishonestly to fool other animals. Why? Dishonesty often helps them survive.

    Many kinds of birds are very successful at fooling other animals. For example, a bird called the plover sometimes pretends to be hurt in order to protect its young. When a predator（猎食动物）gets close to its nest, the plover leads the predator away from the nest. How? It pretends to have a broken wing. The predator follows the “hurt” adult, leaving the baby birds safe in the nest.

  Another kind of bird, the scrub jay, buries its food so it always has something to eat. Scrub jays are also thieves. They watch where others bury their food and steal it. But clever scrub jays seem to know when a thief is watching them. So they go back later, unbury the food, and bury it again somewhere else.

    Birds called cuckoos have found a way to have babies without doing much work. How? They don't make nests. Instead, they get into other birds' nests secretly. Then they lay their eggs and fly away. When the baby birds come out, their adoptive parents feed them.

    Chimpanzees, or chimps, can also be sneaky. After a fight, the losing chimp will give its hand to the other. When the winning chimp puts out its hand, too, the chimps are friendly again. But an animal expert once saw a losing chimp take the winner's hand and start fighting again.

    Chimps are sneaky in other ways, too. When chimps find food that they love, such as bananas, it is natural for them to cry out. Then other chimps come running. But some clever chimps learn to cry very softly when they find food. That way, other chimps don't hear them, and they don't need to share their food.

    As children, many of us learn the saying “You can't fool Mother Nature.” But maybe you can't trust her, either.

    According to the Associated Press (AP), a Chinese scientist claims he successfully created the world's first genetically-edited babies.

    Chinese researcher He Jiankui, a research professor at China's Southern University of Science and Technology in Shenzhen, said he had edited DNA of twin girls born a few weeks ago. ①

    He's claims were immediately criticized by some scientists as unsafe and unethical. This kind of gene editing is forbidden in the United States and many other countries. ②Such changes to a person's DNA can pass to future generations and risk harming other genes.

    In interviews, He Jiankui defended his work. He said he had performed the gene editing to help protect the babies from future infection of HIV, the virus responsible for the disease AIDS. He said the process had “worked safely” and the twin girls were “as healthy as any other babies.” He told the AP he felt a strong responsibility “not just to make a first, but also to make an example” for future research. “Society will decide what to do next,” he said.

    When He's claims became public, the university made a statement saying his work had “seriously went against academic ethics and standards.” University officials said they had no knowledge of his research and had looked into the case. ③

    China's National Health Commission was “highly concerned” about the claims and ordered local health officials “to immediately look into” He's activity. “We have to be responsible for the people's health and will act on this according to the law,” the commission said.

    Scientists discovered in recent years a new way to edit genes that make up a person's DNA throughout the body. The tool, called CRISPR-cas9, makes it possible to change DNA to supply a needed gene or take one away that is causing problems. So far the tool has only been used on adults to treat deadly diseases, and the changes only affected that person.

    ④Kiran Musunuru, a scientist from University of Pennsylvania, told the AP that if such an experiment had been carried out on human beings, it could not be “morally or ethically reasonable.” Julian Savulescu, a medical ethics expert at Britain's University of Oxford, agreed. “If true, this experiment may cause disasters,” he told Reuters.

    However, one well-known geneticist, Harvard University's George Church, defended the attempt to edit genes to prevent infections of HIV. He told the AP that since HIV is “a major and growing public health threat” he finds such experiments “valuable.”

    As our closest neighbor in space, the moon has been the subject of popular myths, songs and poems since ancient times. And it has no less fascinated scientists. But even after centuries of research many questions remain to be answered about Earth's only satellite. Perhaps the Chang'e-4 lunar probe will be able to reveal more of its secrets.

    On Dec 8, the probe lifted off from Xichang Satellite Launch Center in Sichuan Province. It is the first probe to the far side of moon.

    The Earth's gravity slows the moon's rotation, matching it to the speed of its orbit. Thus, the far side of the moon is always dark and has never been seen. It's this sense of the unknown that makes the far side of the moon such an interesting place for scientific and space exploration.

Long exposed to solar winds, the far side may have the special soil and minerals in its upper mantle(地幔).For this reason, Chang'e-4 will study the effect of solar winds on the lunar surface and any minerals found beneath the spacecraft.

    Chang'e-4 is also carrying flower seeds and potato and silkworm eggs to see whether life is possible on the moon. If it is, then the moon will become a more likely destination for space travel in the future. However, due to communication problems, exploration of the dark side will not be easy.

    As the far side is blocked off from us, radio noise coming off Earth is also blocked. This is why China launched the relay satellite Queqiao in May—so that communication between Earth and the probe could go ahead. Power supply will also be a challenge to the mission.

    Chang'e-4 gets energy from the sun through its solar panels. However, a lunar day has the length of 28 Earth days. This means that the probe will need to orbit the moon for over 20 days to be in a position to be able to land in moon daylight and so use its solar panels.

    According to Xinhua, if everything goes well, the satellite will land on the far side on Jan 2.

    The New York Times described the journey as “groundbreaking”, and wrote that it will “give clues to the history and development of the moon”.

    China became the first country to clone a monkey using non-reproductive cells, reducing the need to keep lab monkeys and paving the way for more accurate, effective, and affordable animal tests for new drugs.

    By December of 2017, Chinese scientists had created two clone macaques named "Zhong Zhong" and "Hua Hua" by nuclear transferring of somatic cells -- any cell in the organism other than reproductive cells. This was the similar technology used to create the famous clone sheep Dolly in 1996.

    Tetra, a rhesus monkey born in 1999, is the world's first ever-cloned monkey, but it was done using a simpler method called embryo splitting, but it could only generate four cloned offspring at a time and cannot be genetically modified to suit experimental needs, said Pu Muming, an academician at the Chinese Academy of Sciences and the director of Institute of Neuroscience, CAS. "Cloning a monkey using somatic cells has been a world-class challenge because it is a primate（灵长类）that shares its genetic makeup, therefore all of its complexity, with humans." Pu Muming said.

    "For drug and other lab tests, scientists have to purchase monkeys from all over the world, which is costly, bad for the environment and produces inaccurate results because each monkey might have different genes," Pu said. "By cloning monkeys using somatic cells, we can mass produce large numbers of genetically same offspring in a short time, and even change their genes to suit our needs," he added. "This can save time, cut down experiment costs, and produce more accurate results, leading to more effective medicine."

    Sun Qiang, director of the non-human primate research facility at the institute, said most of the drug trials are currently done on lab mice. However, drugs that work on mice might not work or even have severe side effects on humans because the two species are so different. "Monkeys and Humans are both primates, so they are much closely related and testing on Monkeys is supposed to be as effective as testing on humans," he said. This is especially useful in testing drugs for neural diseases such as Parkinson's disease, metabolic and immune system disease, and tumor, he added. "This achievement will help China lead the world research in an international science project related to neural（神经的）mapping of primate brains,"he said. However, bio labs from the United States, Japan, and European countries are also very able, and they will quickly catch up to China after the monkey cloning technology is made public, Sun added." This means we have to innovate continuously and work extra harder this year to stay ahead," he said.