When someone is happy, can you smell it?

    You can usually tell when someone is happy based on seeing them smile, hearing them laugh or perhaps from receiving a big hug. But can you also smell their happiness? Surprising new research suggests that happiness does indeed have a scent, and that the experience of happiness can be transmitted through smell, reports Phys.org.

    For the study, 12 young men were shown videos meant to bring about a variety of emotions while researchers gathered sweat samples from them. All of the men were healthy and none of them were drug users or smokers, and all were asked to abstain from drinking or eating smelly foods during the study period. 

    Those sweat samples were then given to 36 equally healthy young women to smell, while researchers monitored their reactions. Only women were selected to smell the samples, apparently because previous research has shown that women have a better sense of smell than men and are also more sensitive to emotional signaling—though it's unclear why only men were chosen to produce the scents.

    Researchers found that the behavior of the women after smelling the scents—particularly their facial expressions—indicated a relationship between the emotional states of the men who produced the sweat and the women who sniffed them. 

    “Human sweat produced when a person is happy brings about a state similar to happiness in somebody who breathes this smell,” said study co-author Gun Semin, a professor at Koc University in Turkey.

    This is a fascinating finding because it not only means that happiness does have a scent, but that the scent is capable of transmitting the emotion to others. The study also found that other emotions, such as fear, seem to carry a scent too. This ensures previous research suggesting that some negative emotions have a smell, but it is the first time this has proved to be true of positive feelings.

    Researchers have yet to isolate(分离) exactly what the chemical compound for the happiness smell is, but you might imagine what the potential applications for such a finding could be. Happiness perfumes, for instance, could be invented. Scent therapies（香味疗法）could also be developed to help people through depression or anxiety.

    Perhaps the most surprising result of the study, however, is our broadened understanding of how emotions get communicated, and also how our own emotions are potentially managed through our social context and the emotional states of those around us. 

    Think about vitamin D when you're catching up on summer rays. It's sometimes called the “sunshine vitamin” because it's produced in your skin in response to sunlight. Vitamin D is a fat-soluble (脂溶性的) vitamin in a family of compounds that includes vitamins D-1, D-2, and D-3. It can affect as many as 2,000 genes in the body.

    Vitamin D has several important functions. Perhaps the most vital are regulating the absorption of calcium and phosphorous（磷）, and promoting normal immune system function. Getting enough vitamin D is important for normal growth and development of bones and teeth, as well as improving resistance against certain diseases.

    In addition to its primary benefits, research suggests that vitamin D may also play a role in: reducing your risk of multiple sclerosis（多发性硬化）, according to a 2006 study published in the Journal of the American Medical Association decreasing your chance of developing heart disease, according to 2008 findings published in Circulation helping to reduce your possibility of developing the flu, according to 2010 research published in the American Journal of Clinical Nutrition regulating mood and warding off depression losing weight or preventing heart disease.

    How do you get it? Your body produces vitamin D naturally when it is directly exposed to sunlight. A little can go a long way. All you need is 10 minutes a day of midday, pre-sunscreen sun exposure,especially if you have fair skin. Besides getting vitamin D through sunlight, you can also get it through certain foods and supplements to ensure adequate levels of the vitamin in your blood.

    According to new research from the University of Cambridge in England, sheep are able to recognize human faces from photographs.

    The farm animals, who are social and have large brains, were previously known to be able to recognize one another, as well as familiar humans. However, their ability to recognize human faces from photos alone is novel.

    The recent study, the results of which were published in the journal Royal Society; Open Science, show the woolly creatures could be trained to recognize still images of human faces, including those of former President Barack Obama and actress Emma Watson.

    Initially, the sheep were trained to approach certain images by being given food rewards. Later, they were able to recognize the images for which they had been rewarded. The sheep could even recognize images of faces shown at an angle, though their ability to do so declined by about 15 percent—the same rate at which a human's ability to perform the same task declines.

    “Anyone who has spent time working with sheep will know that they are intelligent and individual animals who are able to recognize their handlers.” said Professor Jenny Morton, who led the Cambridge study. “We've shown with our study that sheep have advanced face-recognition abilities, close to those of humans and monkeys.”

    Recognizing faces is one of the most important social skills for human beings, and some disorders of the brain, including Huntington's disease, affect this ability.

    “Sheep are long-lived and have brains that are similar in size and complexity to those of some monkeys. That means they can be useful models to help us understand disorders of the brain, such as Huntington's disease that develop over a long time and affect cognitive (认识的) abilities. Our study gives us another way to monitor how these abilities change.” Morton said.

    As you enter a university, you turn to a new page where life is quite different from before.{#blank#}1{#/blank#} As far as I can see, there are several aspects you should pay special attention to.

    Manage your free time well. Since there's plenty of spare time every day, a good time-management becomes vital. When free, you can devote yourself to study or go out to visit some scenic spots nearby. If you have special skills or interests, there are various clubs for you to join. {#blank#}2{#/blank#} At the same time you get the chance to make friends with other students.

    Develop self-discipline(自律).College life is nearly completely up to yourself instead of the teachers compared to the high school. So self-discipline makes much more significance. In university the teachers' job is to give classes. {#blank#}3{#/blank#} It is your choice to do them independently or copy. You're supposed to hand in the assignments (任务) punctually. You're also expected to stick to your timetable, keep a balanced diet, etc.

    {#blank#}4{#/blank#} This is the person who will help you with course conflicts, adding or dropping courses, scheduling classes for future terms and deciding on majors. {#blank#}5{#/blank#} He /She should be the person you turn to with any academic issues or conflicts. And don't be afraid of requesting another adviser if you can't contact the first one.

    Bear these tips in mind and I'm sure it can be beneficial to you in the long run.

A. To well adapt yourself to the new environment is of great significance.

B. Get to know your academic adviser.

C. It's where to show your talent.

D. As for the assignments, it is your work.

E. This person is a key resource for you.

F. Buy a calendar to know when assignments are due.

G. Find a perfect place to study in.

    Lucy, whose skeleton（骨骼） was discovered in Ethiopia in 1974, died shortly after she fell out of a tree, according to a new study published Monday in the British journal Nature.

    For their research, Kappelman and Dr. Richard Ketcham used a CT scanner to create more than 35,000 "slices" of Lucy's skeleton. Scientists named her Lucy from the Beatles song "Lucy in the Sky with Diamonds", which was played at the camp the night of her discovery.

    The following analysis of the slices showed sharp, clean breaks seen at the end of Lucy's right humerus （肱骨） are similar to bone breaks seen in victims of falls.

    The researchers concluded that these and other breaks in her skeleton show that Lucy, who is believed to have stood about 3 feet 6 inches and weighed about 60 pounds, fell feet first and used her arms to support herself﹣but that the injury was too severe to have been survivable.

    The researchers estimate that Lucy was going about 35 miles an hour when she hit the ground after falling from a height of roughly 40 feet, according to the statement.

    That sounds plausible. But other scientists are doubtful. "There are countless explanations for bone breaks," Dr, Donald C, Johanson, director of the Institute of Human Origins and one of the scientists who discovered Lucy, said, "The suggestion that she fell out of a tree is largely a just﹣so story and therefore unprovable." Johanson said it was more likely that Lucy's breaks occurred long after she died, saying that "elephant bones appear to have the same kind of breaks, It's unlikely they fell out of a tree.

    But the new research focused on "a small number of breaks" that are consistent with "high﹣energy bone﹣to﹣bone influences" and which differ from the sorts of breaks commonly seen in other collected bones. Kappelman responded in an email, "These appear to have occurred at or near the time of death."

    Plants are boring. They just sit there photosynthesizing (光合作用) while animals have all the fun. Right? Not so much. A new study has found that there is a long history of interactions between ants and plants. The ant and plant co-evolution (协同进化) started with ants feeding on plants and plants evolving ant-friendly features.

    Plants make a number of different structures that are specific for ant use. Some plants have evolved features that persuade ants into defending them from attack from other insects and even mаmmаlѕ. Тhеѕе іnсludе hollow thorns that аntѕ will live іnѕіdе, or ехtra nесtаr (琼浆) оn lеаvеѕ or stems for the ants to eat. Some ants will just cheat and take the nectar and run, but some will stick around and attack anything that tries to hurt the plant. Other plants get ants to help them move their seeds around, by providing them with rich food packets attached to the seeds. The ant will pick up the seed and carry it away, eat the food packet, and leave the seed—often in a nutrient-rich area where it'll grow better, and since it's farther away from its parent, they won't have to compete for resources.

    But scientists weren't sure how the evolutionary relationship between ants and plants got started. If evolution is an arms race between species developing ways to make use of their neighbors, then scientists wanted to know whether plants or ants fired the first shot. It was a chicken-and-egg question, whether things started with ants developing behaviors to take advantage of plants, or plants evolving structures to take advantage of ants.

    The history of ants and plants evolving together goes back to the time of the dinosaurs, and it's not easy to tell from fossils who fired the first shot. However, it is a question of little significance. Scientists say their study maters because it provides a look at how these widespread and complex interactions evolved.