If you ever get the impression that your dog can "tell" whether you look content or annoyed, you may be onto something. Dogs may indeed be able to distinguish between happy and angry human faces, according to a new study.

Researchers trained a group of 11 dogs to distinguish between images（图像）of the same person making either a happy or an angry face. During the training stage, each dog was shown only the upper half or the lower half of the person's face. The researchers then tested the dogs' ability to distinguish between human facial expressions by showing them the other half of the person's face or images totally different from the ones used in training. The researchers found that the dogs were able to pick the angry or happy face by touching a picture of it with their noses more often than one would expect by random chance.

The study showed the animals had figured out how to apply what they learned about human faces during training to new faces in the testing stage. "We can rule out that the dogs simply distinguish between the pictures based on a simple cue, such as the sight of teeth," said study author Corsin Muller. "Instead, our results suggest that the successful dogs realized that a smiling mouth means the same thing as smiling eyes, and the same rule applies to an angry mouth having the same meaning as angry eyes.”

"With our study, we think we can now confidently conclude that at least some dogs can distinguish human facial expressions," Muller told Live Science.

At this point, it is not clear why dogs seem to be equipped with the ability to recognize different facial expressions in humans. "To us, the most likely explanation appears to be that the basis lies in their living with humans, which gives them a lot of exposure to human facial expressions," and this exposure has provided them with many chances to learn to distinguish between them, Muller said.

Theatres and Entertainment

St David's Hall

St David's Hall is the award winning National Concert Hall of Wales standing at the very heart of Cardiff's entertainment centre. With an impressive 2,000-seat concert hall, St David's Hall is home to the annual Welsh Proms Cardiff. It presents live entertainment, including pop, rock, folk, jazz, musicals, dance, world music, films and classical music.

The Hayes, Cardiff CF10 1AH

www.stdavidshallcardiff.co.uk

The Glee Club

Every weekend this is "Wales" premier comedy club where having a great time is the order for both audiences and comedy stars alike. It is hard to name a comedy star who hasn't been on the stage here. If you are looking for the best comedies on tour and brilliant live music, you should start here.

Mermaid Quay, Cardiff Bay, Cardiff CF10 5BZ

www.glee.co.uk/cardiff

Sherman Cymru

Sherman Cymru's theatre in the Cathays area of Cardiff reopened in February 2012. This special building is a place in which theatre is made and where children, artists, writers and anyone else have the opportunity (机会) to do creative things. Sherman Cymru is excited to present a packed programme of the very best theatre, dance, family shows and music from Wales and the rest of the world.

Senghennydd Road, Cardiff CF24 4YE

www.shermancymru.co.uk

New Theatre

The New Theatre has been the home of quality drama, musicals, dance and children's shows for more than 100 years. Presenting the best of the West End along with the pick of the UK's touring shows, the New Theatre is Cardiff's oldest surviving traditional theatre. Be sure to pay a visit as part of your stay in the city.

Park Place, Cardiff CF10 3LN

www.newtheatrecardiff.co.uk

As we age, even if we're healthy, the heart just isn't as efficient in processing oxygen as it used to be. In most people the first signs show up in their 50s or early 60s. And among people who don't exercise, the changes can start even sooner.

"Think of a rubber band. In the beginning, it is flexible, but put it in a drawer for 20 years and it will become dry and easily broken," says Dr. Ben Levine, a heart specialist at the University of Texas. That's what happens to the heart. Fortunately for those in midlife, Levine is finding that even if you haven't been an enthusiastic exerciser, getting in shape now may help improve your aging heart.

Levine and his research team selected volunteers aged between 45 and 64 who did not exercise much but were otherwise healthy. Participants were randomly divided into two groups. The first group participated in a program of nonaerobic (无氧) exercise—balance training and weight training—three times a week. The second group did high-intensity aerobic exercise under the guidance of a trainer for four or more days a week. After two years, the second group saw remarkable improvements in heart health.

"We took these 50-year-old hearts and turned the clock back to 30-or 35-year-old hearts," says Levine. "And the reason they got so much stronger and fitter was that their hearts could now fill a lot better and pump (泵送) a lot more blood during exercise." But the hearts of those who participated in less intense exercise didn't change, he says.

"The sweet spot in life to start exercising, if you haven't already, is in late middle age when the heart still has flexibility," Levine says. "We put healthy 70-year-olds through a yearlong exercise training program, and nothing happened to them at all."

Dr. Nieca Goldberg, a spokeswoman for the American Heart Association, says Levine's findings are a great start. But the study was small and needs to be repeated with far larger groups of people to determine exactly which aspects of an exercise routine make the biggest difference.