Whether rich or poor, parents who have books in the home increase the level of education their children will attain, according to a 20-year study led by Mariah Evans.

    For years, educators have thought the strongest predictor of attaining high levels of education was having parents who were highly educated. But, the study showed that the difference between being raised in a bookless home compared to being raised in a home with a 500-book library has as great an effect on the level of education a child will attain as the difference between having parents who are barely literate (有文化的) and having parents who have a university education.

    Being a sociologist, Evans was particularly interested to find that children of lesser-educated parents benefit the most from having books in the home. What kinds of investments should we make to help these kids get ahead? The results of this study indicate that getting some books into their homes is an inexpensive way that we can help these children succeed. Evans said, "Even a little bit goes a long way. Having as few as 20 books in the home still has a significant impact on motivating a child to a higher level of education, and the more books you add, the greater benefit the children get.”

    The researchers were struck by the strong effect having books in the home had on children's educational attainment even above and beyond such factors as education level of the parents, the father's occupation or the economic level of the country.

    Having books in the home is twice as important as the father's education level, and more important than whether a child was brought up in a developing country or a developed country. Surprisingly, the difference in educational attainment for children born in developed country and children born in developing country was just 2 years, less than two-thirds of the effect that having 500 or more books in the home had on children.

    You might think that “global warming” means nothing more than a rise in the world's temperature. But, rising sea levels caused by it have resulted in the first evacuation (撤离) of an island nation — the citizens of Tuvalu will have to leave their homeland.

    During the 20th century, sea level has risen 8～12 inches. As a result, Tuvalu has experienced lowland flooding of salt water which has polluted the country's drinking water.

    Paani Laupepa, a Tuvaluan government official, reported to the Earth Policy Institute that the nation suffered an unusually high number of fierce storms in the past ten years. Many scientists connect higher surface water temperatures resulting from global warming to greater and more damaging storms.

    Laupepa expressed dissatisfaction with the United States for refusing to sign the Kyoto Protocol, an international agreement calling for industrialized nations to reduce their green house gas emissions (排放), which are a main cause of global warming.“By refusing to sign the agreement, the US has effectively taken away the freedom of future generations of Tuvaluans to live where their forefathers have lived for thousands of years,” Laupepa told the BBC.

    Tuvalu has asked Australia and New Zealand to allow the gradual move of its people to both countries.

    Tuvalu is not the only country that is vulnerable (易受影响的) to rising sea levels. Maumoon Gayoon, president of the Maldives, told the United Nations that global warming has made his country of 311 000 an“endangered nation”.

    Here is some must-know information from a handbook on how people behave in doing business in some countries.

In Brazil

    Brazilians are warm and friendly. They often stand close when talking and it is common for them to touch the person on the shoulder. People often greet each other (particularly women) with light cheek kisses. Schedules tend to be flexible, with business meetings sometimes starting later than planned. But to be safe, be on time. Meals can stretch for hours—there's no such thing as rushing a meal in Brazil. Lunches also can start in the mid to late afternoon. Brazilians are social, preferring face-to-face communication over mails or phone calls.

    In Singapore

    Singaporeans shake hands when they meet and often also greet each other with a small, polite bow. Business cards should be offered and received with two hands. Arriving late is considered disrespectful. So be on time. Efficiency (效率) is the goal, so meetings and dealings often are fast-paced. Singaporeans are direct in their discussions, even when the subject is about money. Rank is important and authority is respected. This determines both people interact in meetings. For example, people avoid disagreeing outright with someone with a higher rank.

    In the United Arab Emirates

    In the UAE, status is important, so the most senior or oldest should be greeted first with their titles. The handshake seems to be longer than elsewhere. So, do not pull away the handshake. Women should cover themselves when it comes to dress. Men also tend to be covered from neck to elbows (肘部) and down to the knees. People do not avoid entertaining in their homes, but they also hold business meals at restaurants. Touching or passing food or eating with your left hand is to be avoided. When meetings are one-to-one, if your host offers you coffee, you should refuse. It might seem odd, but it is a cultural tradition. Coffee should only be accepted if it is always set out or presented.

    In Switzerland

    The Swiss tend to be formal and address each other by last name. They also are respectful of private lives. You should be careful not to ask about personal topics. Punctuality(守时) is vital, something that comes from a deep respect for others' time. Arrive at any meeting or event a few minutes early to be safe. They also have clear structure in their companies. Higher-ups make the final decisions, even if others might disagree. Neat, clean dress is expected. The Swiss follow formal table manners. They also keep their hands visible at the table and their elbows off the table. It is polite to finish the food on your plate.

    The vast majority of us spend our entire lives pulled down by gravity. Then there are astronauts.

This small population of space travelers has given researchers a rare look at what happens to the human body when it's able to spend large amounts of time outside the downward pull of the Earth. This week, a study on one of the largest groups of astronauts yet —34 participants—was published in The New England Journal of Medicine.

    In the new study, a team of international radiologists supported by NASA looked at MRIs of the brains of astronauts before and after their trips to space. The scientists found that upon returning to Earth, many of the astronauts' brains had become repositioned inside their skulls, floating higher than before. In addition, the space between certain brain areas appeared to have shrunk. The changes were more common in astronauts who took longer trips into space.

    The team characterized astronaut trips as short (an average of less than 14 days) or long (an average of about 165 days). Radiologists who didn't know each astronaut's duration（持续时间）in space compared MRIs from before and after their trips.

    Of the 34 total astronauts involved in the study, 18 took long trips to space—spending most of that time on the International Space Station —and of those, 17 returned to Earth with smaller areas between the frontal lobe（脑前额叶）and parietal lobe（顶叶）. The same area of the brain also shrank for three of the 16 astronauts who took shorter trips with the US Space Shuttle Program. The researchers also found that 12 of the ISS astronauts and six of the space-shuttle astronauts returned home with their brains sitting slightly higher in their skulls than before.

    It's not clear what, if anything, these brain changes mean for the health of space travelers. In general, it appears the human body tolerates space travel fairly well: the time astronauts have spent in zero-gravity environments so far doesn't seem to have had any strong or long-lasting effects.

    Every time your fingers touch your cell phone, they leave behind trace of amounts of chemicals. And each chemical offers clues to you and your activities. By studying them, scientists might be able to piece together a story about your recent life, a new study finds.

    A molecule (分子) is a group of atoms. It is the smallest amounts of some chemicals. Your skin is covered in molecules picked up by everything you touched. With each new thing your skin contacts, you leave behind some small share of what it'd touched earlier.

    Researchers at the University of California, San Diego (UCSD) recently studied such chemical leftovers on the phones of 39 volunteers. The study was led by biochemist Amina Bouslimani. To explore those residues (剩余物), the UCSD team wiped the surface of each volunteer's phone with a cotton swab (药签). The scientists also swabbed each person's right hand. Then the researchers compared the chemicals found on each cell phone.

    The scientists discovered as many of the molecules as they could. They then compared those to a database of chemicals. Pieter Dorrestein, a UCSD pharmaceutical chemist, had helped set up that database a few years earlier, which contains various substances, including spices, caffeine and medicines.

    Traces of everything from hundreds to thousands of different molecules turned up on each phone. The molecules suggested what had been in the body, and what each person had handled before touching the phone. From all these molecules, Bouslimani says, “We could tell if a person is likely female, uses high-end cosmetics (化妆品), colors her hair, drinks coffee, prefers beer over wine or likes spicy food.”

    Police already use molecular analyses to look for traces of explosives or illegal drugs. To date, Dorrestein says, he's never heard of police using phone residues to narrow down behaviour clues to search for a suspect. But detectives might one day use such data to track down someone who left a phone behind at a crime scene.

    Tiny Countries You Never knew Existed

    Sao Tome and Principe

    Sao Tome and Principe off Africa's west coast is only 372 square miles, but it has Impressive, undamaged nature, rich in biodiverse species. The amazing needle-like volcanic peak Pico Cao Grande rises 1,000 feet into the air. The islands are home to only around 200,000 people today.

    San Marino

    Only 23 square miles with a population of just 34,000, the little-known country of San Marino, surrounded by Italy, is the world's fifth smallest country. With the UNESCO World Heritage Site of Mount Titano, the country is said to be the oldest republic in the world.

    Dominica

    Dominica covers only 290 square miles, with some of the best diving in the Caribbean, including the UNESCO World Heritage Site of volcanic Morme Trois Pitons National Park. In Dominica, you'll see rainforests, waterfalls, and coastal views. The island is also home to the only remaining population of the Kalinago, who are part of the island's 74, 900 inhabitants.

    Kiribati

    This Pacific island country 33 coral islands is 313 square-miles, but it's the only country in the world to fall into all four hemispheres (半球). The country's 109, 000 residents live in only 21 of the islands see this tropical paradise before it is no longer--rising seas are threatening to swallow the country whole.