Recent summer temperatures in parts of Australia were high enough to melt asphalt. As global warming speeds up the heat and climatic events increase, many plants may be unable to cope. But at least one species of eucalyptus tree can resist extreme heat by continuing to “sweat” when other essential processes stop, a new study finds.

    As plants change sunlight into food, or photosynthesize (光合作用), they absorb carbon dioxide through pores on their leaves. These pores also release water via transpiration(蒸腾), which circulates nutrients through the plant and helps cool it by evaporation(蒸发). But exceptionally high temperatures are known to greatly reduce photosynthesis—and most existing plant models suggest this should also decrease transpiration, leaving trees in danger of fatally overheating. Because it is difficult for scientists to control and vary trees' conditions in their natural environment, little is known about how individual species handle this situation.

    Ecologist John Drake of the S.U.N.Y. College of Environmental Science and Forestry and his colleagues grew a dozen Parramatta red gum (Eucalyptus parramattensis) trees in large, climate-controlled plastic pods that separated the trees from the surrounding forest for a year in Richmond, Australia. Six of the trees were grown at surrounding air temperatures and six at temperatures three degrees Celsius higher. The researchers withheld (扣留) water from the surface soil of all 12 trees for a month to imitate a mild dry spell, then induced a four-day “extreme” heat wave: They raised the maximum temperatures in half of the pods（three with surrounding temperatures and three of the warmer ones）— to 44 degrees ℃.

    Photosynthesis ground to a near halt in the trees facing the artificial heat wave. But to the researchers' surprise, these trees continued to transpire at close-to-normal levels, effectively cooling themselves and their surroundings. The trees grown in warmer conditions coped just as well as the others, and photosynthesis rates bounced back to normal after the heat wave passed, Drake and his colleagues reported online in Global Change Biology.

    The researchers think the Parramatta red gums were able to effectively sweat — even without photosynthesis — because they are particularly good at tapping into water deep in the soil. But if a heat wave and a severe drought (干旱) were to hit at the same time and the groundwater was exhausted, the trees may not be so lucky, Drake says.

    Other scientists call the finding encouraging. “It's definitely good news,” says Trevor Keenan, an ecologist at Lawrence Berkeley National Laboratory, who was not part of the study. “It would be very interesting to know how this translates to other species,” he adds. Drake hopes to conduct similar experiments with trees common in North America.

    A young woman carrying a three-year-old child got on a bus. The conductor hurried to give her a warm welcome and then kindly asked the other passengers to make more room for the woman and her child. On seeing this, people were surprised and began to talk. "You know this conductor used to be very rude. Now suddenly he has changed his bad behavior, "said a middle-aged man.

    "Yes, he should be praised and we must write a letter to the company," said a second passenger. "That's right," another lady said, "I wish a newspaper reporter were here so that more people could learn from this conductor.”

    Just then a gentleman who looked like a teacher turned to the conductor and said, "Excuse me, but can I know your name, please? Your excellent service must be praised..."

    Before he could open his mouth, the three-year-old child sitting on the young woman's lap interrupted, "I know his name. I call him Dad."

    One recent night, while I was leafing through its pages of an old journal, my eyes met a quote by the British writer Graham Greene that I had marked. “A prejudice had something in common with an ideal.” In other words, ideals general descriptions of people's expectations of themselves and others can often lead us to unreasonable ideas. It got me thinking about how we often allow ourselves to generalize about groups of people. We like to stereotype people by the color of their skin, the year of their birth or any other related factors.

    I grew up in a multi-racial corner of America. The different groups were often subject to narrow stereotypes: Jewish people were “greedy,” Mexicans were “poorly educated,” and Asians were “good at math.” These labels were taught to us from a young age. They wormed their way into our belief systems, harming how we came to see others. It made me sad growing up to see people repeat these stereotypes as if they were true. The rush-to-judgment of people breeds a culture of discrimination (歧视).

    You can also see these over-generalized description being made against today's Chinese people. Whether it be a lack of interest or worry among millennials (千禧一代) being described as “monkish,” or “dad-fashion (复古作风)” which has given the “greasy middle-aged men” tag, stereotypes always seem to gain a foothold in the consciousness of our society. But these generalizations do real harm as these myths may become part of the wider population.

    It's about time that we, as a society, walked away from generalizations and stereotypes. I leave you with the words of Martin Luther King Jr. from his famous “I Have a Dream” speech: “I look to a day when people will not be judged by the color of their skin, but by the content of their character.” By reserving judgment and really getting to know the individual, you might just find your irrational ideas have no foundation.

                                                              Student Sports

    Are you tired of spending all your free time studying, going online, or playing video games? If the only muscles (肌肉) you use are for typing on a keyboard or moving a mouse, then it's time to visit the Student Recreation Center!

    Our Student Sports program runs both competitive leagues (联赛) for serious players and “just-for-fun” leagues for everybody else in a variety of team and individual (个人的) sports. In the competitive league, each team will compete three times per week for a 10-week period. The team with the most victories will win a prize at the end of the tenth week. In “just-for-fun” leagues, teams play only on weekends, and there are no prizes given. Both types of leagues offer volleyball, soccer, softball, tennis, golf, basketball, and more than a dozen other sports. It's a great chance to go out with your friends, make new friends, and get some exercise at the same time.

    The spring season is coming soon, and it's easy to get started. Stop by the Student Sports desk in the Student Recreation Center or go online to www.studnetrec.OurUniv.edu/studentsports. Whether you come down to visit the center or register (登记) online, you will have to fill out a simple form. On this form you will be asked for your name, phone number, email address, your ability level (beginner, middle, or advanced), and the times you are free to play.

    So why don't you pick up your phone and send one more text: Tell your friends that the last day to sign up for the spring season is March 1! But don't wait until the last minute — if you sign up for early registration before February 21, you'll get free tickets to our famous Beach Volleyball Picnic coming up on March 15!

    Here at the Student Recreation Center, we truly believe that getting fit is fun. We hope you'll be joining us for another great season of Student Sports!

Both humans and animals have enemies. It is easy for us to know the difference between our friends and our enemies. But can other animals do the same? Elephants can! They can use their sense of vision and smell to tell the difference between people who mean a threat and those who do not. In Kenya, researchers find that elephants react differently to clothing worn by men of the Maasai and Kamba ethnic groups. Young Maasai men hunt animals and thus mean a threat to elephants; Kamba men are mainly farmers and are not a danger to elephants.

In an experiment conducted by animal scientists, elephants were first presented with clean clothing or clothing that had been worn for five days by either a Maasai or a Kamba man. When the elephants noticed the smell of clothing worn by a Maasai man, they moved away from the smell faster and took longer to relax than when they noticed the smells of either clean clothing or clothing worn by a Kamba man.

Clothing color also plays a role. In the same study, when the elephants saw red clothing not worn before, they reacted angrily, as red is typically worn by Maasai men. Rather than running away as they did with the smell, the elephants acted angrily toward the red clothing.

The researchers believe that the elephants' emotional reactions are due to their different senses of smell and sight. Smelling a possible danger means that a threat is nearby and the best thing to do is run away and hide. Seeing a potential threat without its smell means that risk is low. Therefore, instead of showing fear and running away, the elephants express their anger and become aggressive.

    In 2001, British Prime Minister, Tony Blair said," We celebrate the diversity(多样性) in our country, get strength from the cultures and the races that go to make up Britain today."

    People from all cultures and races can be found in every corner of Britain and each person in his or her own way has contributed to making Britain the place it is today.

    If you walk down a street in Britain, especially in the bigger cities, you will usually see people with different hair, skin and eye colors. They may have white, brown or black skin and blonde, brown, black or red hair, with blue, black, brown or green eyes. Many of the people you will see will be British people but they all look different because the people of Britain are a mixed race.

    Britain is and has always been a mixed race society. Early in the British history they were invaded by Romans, Saxons, Vikings and Normans armies and later Africans were brought to Britain by force in the seventeenth and eighteenth centuries as slaves or servants. Over the years, thousands of people have been forced by persecution(迫害) or hunger to leave France, Ireland, Russia, and other countries, and have settled in Britain.

    About 8% of the population of Britain today are people from other cultures and races. That is 4.6 million people. According to a BBC report in September 2005, immigration (移民) made up more than half of Britain's population growth from 1991 to 2001.The Guardian newspaper reported in 2007 that the number of immigrants to the UK was 145,000 a year.

    People moving to Britain have brought their own cultures with them and try to keep them alive. An excellent example of this is the Notting Hill Carnival which celebrates the Caribbean culture and is now a very big part of British life today.