Research finds out why some people are constantly under attack from the bloodsucking insects while others walk free.

    For those unfortunate enough to feature highly on the mosquito hit list, summer nights can be synonymous with mosquito bites. Yet others hardly ever get bitten. So how do the bloodthirsty insects select their victims?

    The insects' tastes may seem arbitrary. However, research shows that when mosquitoes make their choices between potential victims, it all comes down to scent (气味).

    “Mosquitoes are attracted by carbon dioxide and heat, which everyone gives off. But mosquitoes are also attracted by certain scents,” says Karl-Martin Vagn Jensen, the head of research at the Department of Agricultural Science at Arhus University.

    According to Jensen, it has not yet been confirmed exactly what the scents in question are. But research does indicate that some scents are more attractive to mosquitoes than others.

    “All the lab employees rubbed petri dishes (培养皿) against their stomachs. In that way, their scents were put on the dishes, which were then put in a container full of mosquitoes,” he says. “The mosquitoes repeatedly landed on some of the petri dishes, but didn't go anywhere near the others.”

    Perhaps taking inspiration from popular fiction, there are also those who consider garlic as an excellent repellent (驱虫剂) against the winged bloodsuckers. According to the researcher, this strategy may not be entirely fruitless. “As far as I know, there is no scientific proof that eating garlic works. But there may be something to the theory that it's possible to mask scent with garlic,” he says. The only reliable method of protection against mosquitoes is to use repellents that are sold over the counter. It contains some smells that can confuse the mosquitoes. When the mosquito comes closer, it uses smell, heat and carbon dioxide to decide whether to bite. But if it is confused by a repellent, it will never get that far.

    （I）It was a surprising announcement: SpaceX, a private company（私人公司）, said it would fly two people to the moon next year (2019). This has not been attempted since NASA's Apollo moon landings about 45 years ago. In the news conference, Elon Musk. SpaceX founder said two people have already paid SpaceX a “wonderful” amount of money to send them on a weeklong flight just beyond the moon.

    （II）Exercise reduces the risks of dying from all causes, including cancer and heart disease. But many people who work all week have little time for exercise. They try to take exercise or do chores to increase their heart rates over the weekend. A new study suggests that it is healthy to do that, which can reduce their risk of cancer and cardiovascular（心血管疾病）disease.

    （III）Scientists in London have found a possible way to solve the problem of plastic bottle waste. They have made a water bottle you can eat. The product is called Ooho, made of seaweed, a plant that grows in the ocean. Oohos are tasteless and look like bubbles or balls. They can hold water or any other liquid（液体）inside. When people drink Oohos, the outside bursts in the mouth and can be eaten. Even if you throw it away, it will degrade in about four weeks. It is good for the environment.

    You probably know who Marie Curie was, but you may not have heard of Rachel Carson. Of the outstanding ladies listed below, who do you think was the most important woman of the past 100 years?

    Jane Addams (1860-1935)

    Anyone who has ever been helped by a social worker has Jane Addams to thank. Addams helped the poor and worked for peace. She encouraged a sense of community by creating shelters and promoting education and services for people in need. In 1931, Addams became the first American woman to win the Nobel Peace Prize.

    Rachel Carson (1907-1964)

    If it weren't for Rachel Carson, the environmental movement might not exist today. Her popular 1962 book Silent Spring raised awareness of the dangers of pollution and the harmful effects of chemicals on humans and on the world's lakes and oceans.

    Sandra Day O'Connor (1930-present)

    When Sandra Day O'Connor finished third in her class at Stanford Law School, in 1952, she could not find work at a law firm because she was a woman. She became an Arizona state senator (参议员) and, in 1981, the first woman to join the U.S. Supreme Court. O'Connor gave the deciding vote in many important cases during her 24 years on the top court.

    Rosa Parks (1913-2005)

    On December 1,1955, in Montgomery, Alabama, Rosa Parks would not give up her seat on a bus to a white passenger. Her simple act landed Parks in prison. But it also set off the Montgomery bus boycott. It lasted for more than a year, and kicked off the civil-rights movement. “The only tired I was, was tired of giving in,” said Parks.

    If humans pump enough carbon dioxide (CO₂) into the atmosphere, the stratocumulus clouds(层积云) could disappear, and the earth's temperature could climb sharply to heights not predicted in current climate models. It would burn the planet. That's the conclusion of a paper published in the journal Nature Geoscience and described in detail by Natalie Wolchover for Quanta Magazine.

    As Wolchover explained, clouds have long been one of the great uncertainties of climate models. Computer models that easily capture the complexity and detail of most climate systems just aren't powerful enough to predict worldwide changes in cloud behavior. But clouds are important. They reflect sunlight away from the earth's surface. And stratocumulus clouds are those white blankets you might have seen as you looked out the window of arm airplane, rolling out below you and hiding the ground Researchers suspect that certain sudden, past jumps in temperature may have been caused by changes to clouds like these.

    For the new research, scientists modeled just a small patch of sky using a supercomputer. They found that if carbon dioxide levels reach about 1, 200 parts per million(ppm) in the atmosphere, stratocumulus clouds break up. That's a very high carbon dioxide concentration.  Right now, levels have climbed past 410 ppm--a dangerous change from 280 ppm before the Industrial Revolution.

    But humans put more and more CO₂ into the atmosphere every year. If current trends continue, the earth could reach 1, 200 ppm within 100 to 150 years. This could happen if our society doesn't follow through on any of its commitments to reduce emissions(排放), Wolchover reported. And even if it does, the result would be another 8 degrees Celsius of heat added to the global average, on top of the dangerous changes already underway due to greenhouse gases.

    That's an enormous change, and it goes beyond predictions of worldwide ice melt and catastrophic sea level rise. And, once the stratocumulus clouds are gone, Wolchover reported, they likely wouldn't reappear until atmospheric carbon dioxide levels dropped below where they are currently.

    There's still some uncertainty in the data. The 1, 200 ppm figure could change as scientists look into the issue further.

Guide to Stockholm University Library

    Our library offers different types of studying places and provides a good studying environment.

Zones

    The library is divided into different zones. The upper floor is a quiet zone with over a thousand places for silent reading, and places where you can sit and work with your own computer. The reading places consist mostly of tables and chairs. The ground floor is the zone where you can talk. Here you can find sofas and armchairs for group work.

Computers

    You can use your own computer to connect to the wi-fi specially prepared for notebook computers; you can also use library computers, which contain the most commonly used applications, such as Microsoft Office. They are situated in the area known as the Experimental Field on the ground floor.

Group-study places

    If you want to discuss freely without disturbing others, you can book a study room or sit at a table on the ground floor. Some study rooms are for 2～3 people and others can hold up to 6～8 people. All rooms are marked on the library maps.

    There are 40 group-study rooms that must be booked via the website. To book, you need an active University account and a valid University card. You can use a room three hours per day, nine hours at most per week.

    Storage of Study Material

    The library has lockers for students to store course literature. When you have obtained at least 40 credits, you may rent a locker and pay 400 SEK for a year's rental period.

    Rules to be Followed

    Mobile phone conversations are not permitted anywhere in the library. Keep your phone on silent as if you were in a lecture and exit the library if you need to receive calls.

    Please note that food and fruit are forbidden in the library, but you are allowed to have drinks and sweets with you.

China Experience Tours

    China Experience Trip

    Beijing →Shanghai →Xi'an (8days)

    Price: Adult $1,517 p/p Under 17 $1,230

    Imagine you are a king or queen when entering the great Forbidden City

    Have a hike on the world famous Great Wall

    Discover the Terracotta Warriors (兵马俑)

    Admire Shanghai where east meets west and walk around some local markets

    Glories of China

    Beijing →Xi'an →Guilin →Yangshuo →Shanghai (11days)

    Price: Adult $2,219 p/p. Under 17 $1,650

    Discover more of China's extraordinary history from Beijing and Xi'an

    Visit the easy part of the Great Wall at Mutianyu

    Cycle near Yangshuo and admire the beautiful rural scenery

    Discover Shanghai lifestyles ancient and modern

    China Impression Experience

    Beijing →Xi'an →Yangtze River →Shanghai (11 days)

    Price: Adult $2, 329 p/p. Under 17 $1,810

    Explore both the ancient cultures and modern features, and relax on the yangtze river Cruise (乘船游览) to see the various ideas of China. Your guides will show you around not only the most classic spots, like the Forbidden City, the Great Wall, the Terracotta Army, and the Three Gorges but also take you for a local experience by visiting lovely giant pandas and local markets.

    Cultural and Natural Wonders of China

    Beijing →Xi'an → Zhangjiajie →Shanghai (11days)

    Price: Adult $2,159 p/p. Under 17 $1,360

    Wind your way from Beijing to Shanghai in style and discover. Climb up the Great Wall, walk around the Forbidden City while listening to the stories of kings, and see the Great "Avatar Mountain" in Zhangjiajie.