Exercise may help to safeguard the mind against depression through previously unknown effects on working muscles, according to a new study involving mice.

    Mental health experts have long been aware that even mild, repeated stress can contribute to the development of depression and other mood disorders in animals and people. Scientists have also known that exercise seems to cushion against depression. But precisely how exercise, a physical activity can lessen someone's risk for depression, a mood state, has been mysterious. So for the new study, researchers at the Karolinska Institute in Stockholm studied the brains and behavior of mice in a complicated and novel fashion.

    We can't ask mice if they are feeling cheerful or in low spirits. Instead, researchers have pictured certain behaviors that indicate depression in mice. If animals lose weight, stop seeking out a sugar solution when it's available — because, probably, they no longer experience normal pleasures — or give up trying to escape from the cold-water zone just freeze in place, they are categorized as depressed. And in the new experiment, after five weeks of frequent but low-level stress, such as being lightly shocked, mice displayed exactly those behaviors. They became depressed.

    The scientists could then have tested whether exercise blunts (延缓) the risk of developing depression after stress by having mice run first. But, frankly, from earlier research, they wanted to know how, so they bred pre-exercised mice. A wealth of earlier research by these scientists and others had shown that aerobic exercise, in both mice and people, increases the production within muscles of an enzyme (酶) called PGC-1alpha. The Karolinska scientists suspected that this enzyme somehow creates conditions within the body that protect the brain against depression. Then, the scientists exposed the animals, which without exercising, were in high levels of PGC-1alpha to five weeks of mild stress. The mice responded with slight symptoms of worry. But they did not develop depression. They continued to seek out sugar and fought to get out of the cold-water zone. Their high levels of PGC-1alpha appeared to make them depression-resistant. Finally, to ensure that these findings are relevant to people, the researchers had a group of adult volunteers complete three weeks of frequent endurance training, consisting of 40 to 50 minutes of moderate cycling or jogging. The scientists conducted muscle biopsies (活体检查) before and after the program and found that by the end of the three weeks, the volunteers' muscle cells contained substantially more PGC-1alpha than at the study's start. The finding of these results, in the simplest terms, is that “you reduce the risk of getting depression when you exercise,” said Maria Lindskog, a researcher at the Karolinska Institute.

    Should we allow modern buildings to be built next to older buildings in a historic area of a city? In order to answer this question, we must first examine whether people really want to preserve the historic feel of an area. Not all historical buildings are attractive. However, there may be other reasons—for example, economic (经济的) reasons—why they should be preserved. So, let us assume that historical buildings are both attractive and important to the majority of people. What should we do then if a new building is needed?

    In my view, new architectural styles can exist perfectly well alongside an older style. Indeed, there are many examples in my own home town of Tours where modern designs have been placed very successfully next to old buildings. As long as the building in question is pleasing and does not dominate (影响) its surroundings too much, it often improves the attractiveness of the area.

    It is true that there are examples of new buildings which have spoilt (破坏) the area they are in, but the same can be said of some old buildings too. Yet people still speak against new buildings in historic areas. I think this is simply because people are naturally conservative(保守的)and do not like change.

Although we have to respect people's feelings as fellow users of the buildings, I believe that it is the duty of the architect and planner to move things forward . If we always reproduced what was there before, we would all still be living in caves. Thus, I would argue against copying previous architectural styles and choose something fresh and different , even though that might be the more risky choice.

    A person's chances of falling ill from a new strain (菌株) of flu are at least partly determined by the first strain they ever met with, a study suggests.

    Research in Science Journal looked at the 18 strains of influenza A ( 甲型流感) and the hemagglutinin protein (红血球凝集素蛋白) on its surface. They say there are only two types of this protein and people are protected from the one their body meets first, but at risk from the other one. A UK expert said that could explain different patterns in flu pandemics (流行病).The researchers, from University of Arizona in Tucson and the University of California, Los Angeles, suggest their findings could explain why some flu outbreaks cause more deaths and serious illnesses in younger people. The first time a person's immune system meets a flu virus, it makes antibodies targeting hemagglutinin protein that sticks out of the surface of the virus — like a lollipop (棒棒糖).

    Even though there are 18 types of influenza A, there are only two versions of hemagglutinin. The researchers, led by Dr Michael Worobey, classed them as "blue" and "orange" lollipops. They said people born before the late 1960s were exposed to "blue lollipop" flu viruses — H1 or H2 — as children. In later life they rarely fell ill from another "blue lollipop" flu — H5N1 bird flu, but they died from "orange" H7N9. Those born in the late 1960s and exposed to "orange lollipop" flu — H3 — have the opposite pattern.

    His team looked at cases of H5N1 and H7N9 — two kinds of bird flu which have affected hundreds of people, but have not developed into pandemics. The researchers found a 75% protection rate against severe disease and 80% protection rate against death if patients had been exposed to a virus with the same protein version when they were children.

    Dr Worobey said the finding could explain the unusual effect of the 1918 "Spanish flu" pandemic, which was more deadly among young adults. "Those young adults were killed by an H1 virus and from blood analysed many decades later there is a pretty strong indication that those individuals had been exposed to a mismatched H3 as children and were therefore not protected against H1. The fact that we are seeing exactly the  same pattern with current H5N1 and H7N9 cases suggests that the same fundamental processes may govern both the historic 1918 pandemic and today's contenders (斗争者) for the next big flu pandemic."

    Jonathan Ball, professor of University of Nottingham, said, "This is a really neat piece of work and provides a reason why human populations have been sensitive to different strains of bird influenza over the past 100 years or so. The findings are based on analysis of patient records and they certainly need further proof in the laboratory, but nonetheless the results are pretty amazing and inspiring."

    David Beckham was born in 1975 in London, at a place called Leytonstone. When he was a young boy, his greatest passion was in football. He played it whenever he had the chance. Sometimes he would go and watch a game with his friends. When David Beckham was 12 years old, he won the Bobby Charlton Soccer Skills award. This was an important step forward for this young boy, and it led him to go for a visit to a football training camp in Spain. As a boy he played for schools of Essex and also for his county team.

    In 1991, he became a trainee with Manchester United. This meant that he could practice football as much as he wanted to and play for the highly successful Manchester United Youth Cup team and Under-21 team. In April, 1995 he played his first football league game against Leeds Untied. During 1995 and 1996, David became a regular member of the team and Manchester United won in both football seasons, with David scoring many goals（进球）.

    His goals made him a household name. In the first game of the 1996-1997 season, he scored a surprising goal from beyond the halfway line and became famous overnight. He continued to score astonishing goals, especially from free-kicks. The speed of one of his shots was timed at 157 km/h. He also had the ability to make the ball go from left to right, or right to left, whenever he chose. Goalkeepers were never sure where the ball was going, and it regularly ended up in the goal.

    Seaside Escape

    2 Bedrooms, Sleeps 6. 2 Bathrooms

    2 Nights Minimum(最少量，最低限度)

    Seaside Escape is made up of two town houses. The town houses are separate and private. Each house is well decorated and furnished, with fully equipped kitchens, two bedrooms, two bathrooms and a washing machine. Each town house also has a private garage, free WiFi Internet access, and two televisions.

    We have a 50 x 25 foot swimming pool, with direct beach access only steps from your front door. You are only a ten-minute drive from Orlando International Airport.

House rules:

    Kid-friendly

    Pets not allowed

    Smoking not allowed

    The Beach House 212

    2 Bedrooms, Sleeps 6. 2 Bathrooms

    3 Nights Minimum

    Located on the beach in Cocoa Beach, this family-friendly town house has all the equipment of home and is newly furnished. It is a 45-minute drive to Orlando International Airport.

Newly acquired furniture will give you a high standard of comfort!

House rules:

    Kid-friendly

    Smoking not allowed

    We do “not” allow pets

    The Dolphin suite

    1 Bedroom, 1 Bathroom, Sleeps 2

    The Dolphin suite is small but very clean, comfortable, private and unique, perfect for a couple. It is very close to all the downtown restaurants and a 2-minute walk to our beautiful beach. About an hour's drive from Orlando International Airport.

We supply beach towels and chairs. Just bring your sunscreen. Please message for any other questions you might have.

    House rules:

    Adults only

    Pets allowed

    Smoking not allowed

    The Shell Beach House

    4 Bedrooms, 4 Bathrooms, Sleeps 12

    Relax in this welcoming Beach House, just a one-minute walk to the beautiful beach. The Shell Beach House sleeps 10 comfortably and 12 at most.

    The Shell Beach House has an ocean view sun terrace(阳台)。It's an outstanding spot for viewing the ocean, the stars, the sunrise, the rising full moon over the waves.

House rules:

    Kid-friendly

    Pets not allowed

    Smoking not allowed

    No loud parties, just normal fun and gatherings allowed.

    Lima, the capital of Peru (秘鲁), has countless museums that tourists can't afford to miss. Now start packing up and prepare for your perfect Peruvian history exploration at these wonderful museums.

    ◆Larco Museum

    Stepping inside, visitors get to learn the 5,000-year history of Peru through an unbelievable collection of objects. The best thing about the museum is that it keeps the door to the storeroom open to visitors so that they can admire its collection closely.

    ◆Gold Museum of Peru

    If you like shiny objects or precious metals, then plan a trip to the Gold Museum of Peru. In ancient times, the Peruvian people were celebrated for their skills in metals. And the museum is aimed at preserving this heritage.

    ◆Lima Art Museum

    Art experts are much pleased as the city is also home to the Lima Art Museum. Its permanent exhibit of over 1, 200 pieces is merely a small part of its amazing collection of more than 17, 000 artifacts. The highlight of the museum is its collection of Carlos Baca-Flor's masterpieces, which is considered to be the most complete set in the world.

    ◆Museum of Italian Art

    The only museum dedicated to European art in Peru, the Museum of Italian Art is a storehouse of classical and contemporary paintings and sculptures belonging to the 20th century. The property is easily accessible by a short walk from the Lima Art Museum.

    ◆Museum of Natural History

    Last but certainly not least is the Museum of Natural History. Giving a glimpse into the rich biodiversity in Peru, the museum has on display the skeletons of a sperm whale and fossils of several mammals.