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.

A trial project by the Montreal Children's Hospital suggested that the use of medical hypnosis(催眠)can reduce pain and anxiety in patients. The project also resulted in a reduction in the amount of medicines used to perform medical-imaging imaging(医学影像) procedures.

"During the examination children don't move. It works perfectly. It's amazing," said Johanne L'Ecuyer, a medical-imaging technologist at the hospital.

The project was inspired by a French team from Rouen University Hospital Centre where examinations are done under hypnosis instead of general anesthesia(麻醉).

A French medical-imaging technologist-also a hypnotist — was invited to train a few members in the medical-imaging department of the children's hospital. In all, 80 examinations were conducted for the project between January and September, 2019, focusing on the imaging procedures that would cause anxiety.

Hypnosis is not a state of sleep: It is rather a modified(改变的)state of consciousness. The technologist will guide the patient to this modified state—an imaginary world that will disassociate itself more and more from the procedure that follows.

"The technologist must build up a story with the patient," Ms. L'Ecuyer said. "The patient is left with the power to choose what he wants to talk about. Do you play sports? Do you like going to the beach? We establish a subject that we will discuss throughout the procedure. "

Everything that happens next during the procedure must be related to this story — an injection (注射) becomes the bite of an insect; the heat on the skin becomes the sensation of the sun and a machine that rings becomes a police car passing nearby.

"The important thing is that the technologist associates what is happening outside the patient's body with what the patient sees in his head," Ms. L'Ecuyer said. "It requires creativity on the part of the technologist, imagination, a lot of patience and kindness."

The procedure appealed to the staff a lot when it was introduced in January. It spread like wildfire that someone from France was here to train the technologists," Ms. L'Ecuyer said. She added that she had a line of staff at her door wanting to take the training.

The Government's sugar tax on soft drinks has brought in half as much money as Ministers first predicted it would generate, the first official data on the policy has shown.

First announced in April, 2016, the tax which applies to soft drinks containing more than 5g of sugar per 100ml, was introduced to help reduce childhood obesity（肥胖）. It is believed that today's children and teenagers are consuming three times the recommended level of sugar, putting them at a higher risk of the disease.

Initially the sugar tax was expected to make £520m a year for the Treasury. However, data of the first six months showed it would make less than half this amount. At present it is expected to generate £240m for the year ending in April 2019, which will go to school sports.

It comes after more than half of soft drinks sold in shops have had their sugar levels cut by manufacturers（制造商）so they can avoid paying the tax. Drinks now contain 45 million fewer kilos of sugar as a result of manufacturers' efforts to avoid the charge, according to Treasury figures. Since April drinks companies have been forced to pay between 18p and 24p for every litre of sugary drink they produce or import, depending on the sugar content.

However, some high sugar brands, like Classic Coca Cola, have accepted the sugar tax and are refusing to change for fear of upsetting consumers. Fruit juices, milk-based drinks and most alcoholic drinks are free of the tax, as are small companies manufacturing fewer than 1m litres per year.

Today's figures, according to one government official, show the positive influence the sugar tax is having by raising millions of pounds for sports facilities（设施）and healthier eating in schools. Helping the next generation to have a healthy and active childhood is of great importance, and the industry is playing its part.