Was St Nicholas, the 4th century saint who inspired the iconography of Santa Claus, a legend or was he a real person?
New Oxford University research has revealed that bones long venerated as relics of the saint, do in fact date from the right historical period.
One of the most revered Orthodox Christian saints, the remains of St Nicholas have been held in the Basilica di San Nicola, Bari, Southern Puglia, since 1087, where they are buried in a crypt beneath a marble altar.
Over the years relic fragments have been acquired by various churches around the world, calling into question how the bones can all be from the same person.
Using a micro-sample of bone fragment, scientists have for the first time tested one of these bones.
The radio carbon dating results pinpoint the relic's age to the 4th century AD - the time that some historians allege that St Nicholas died, around 343 AD.
The results suggest that the bones could in principle be authentic and belong to the saint.
"Many relics that we study turn out to date to a period somewhat later than the historic attestation would suggest," study co-author Professor Tom Higham said.
"This bone fragment, in contrast, suggests that we could possibly be looking at remains from St Nicholas himself."
St Nicholas is thought to have lived in Myra, Asia Minor, which is now modern day Turkey.
According to legend he was a wealthy man who was widely known for his generosity, a trait that inspired the legend of Father Christmas as a bringer of gifts on Christmas Day.
Believed to have been persecuted by the Emperor Diocletian, the saint died in Myra, where his remains became a focus of Christian devotion
His remains are said to have been taken away by a group of Italian merchants and transported to Bari, where the bulk of them sit to this day in the Basilica di San Nicola.
Hallucinating linked to musicianship?
A person's likelihood of experiencing hallucinations - and their musical aptitude - has been linked to a certain brain structure.
Previous research has showed that musicians have increased white matter integrity in a specific part of the brain called the corpus callosum, a thick band of nerve fibres that connects the left and right halves of the brain, enabling communication between the hemispheres.
In psychotic individuals with auditory verbal hallucinations, the integrity of the corpus callosum has been found to be reduced.
Researchers from the University of Liverpool's Psychological Sciences department identified 38 healthy individuals aged between 18 and 63 and tested their propensity to hallucinate, musical aptitude and measured their detailed brain structure using an MRI scanner.
The researchers observed that participants with higher musical aptitude showed lower hallucination proneness.
More importantly, the research revealed musical aptitude was positively associated with corpus callosum integrity whereas hallucination proneness was associated with lower integrity in the fibres connecting the two hemispheres of the brain.
A statistical analysis indicated that the relationship between hallucination proneness and musical aptitude is mediated by microstructure in the corpus callosum.
"These results could have important clinical implications," study co-author Amy Spray said.
"If musical aptitude increases the white matter integrity of the corpus callosum, musical training could potentially counteract an individual's predisposition of hallucinations.
"Future research should address whether rehabilitation approaches that include musical training can benefit patients with psychosis."
The parasites that can turn you into 'moving zombies'
Scientists have previously shown that a parasite from cats can infect people's brain and affect our behaviour.
Now, researchers at Stockholm University have discovered how the parasite takes control of our cells.
"We have decoded how the parasite takes control of immune cells, converting them into moving 'zombies' which spread the parasite in the body," study co-author Professor Antonio Barragan said.
The infection toxoplasmosis is caused by the parasite Toxoplasma gondii and is widely spread.
It's estimated that 30-50 per cent of the global human population are carriers.
Cats are the parasites' main host, but the infection is also spread among other animals, including humans.
A series of studies have previously shown that the parasite affects the brain of infected rats so that they lose fear of cats and even become attracted to cats' smell, making them an easy prey.
This is how the parasite is spread onward, by ensuring that the rat is eaten by a cat.
Toxoplasmosis is life-threatening to people with impaired immune systems and to unborn fetuses, but causes only mild symptoms in healthy individuals.
However, there are studies showing that mental illnesses such as schizophrenia, depression and anxiety disorder are more common in people who are carriers of Toxoplasma gondii.
There are also studies indicating that the parasite may affect aggressive or risky behavior.
The researchers have now been able to show how the parasite takes control and force immune cells around the body to spread it, eventually reaching the brain.
When we become infected with Toxoplasma, for example, by eating insufficiently cooked meat or by contact with cat faeces, the parasite ends up in the stomach.
It then passes through the intestinal wall and is met by immune cells that would normally kill it.
Instead, immune cells become Trojan horses.
By secreting the substance GABA, they can spread the infection into the body.
"Is it a coincidence or evolution?" Barragan said.
"It resembles how nerve cells speak to each other in our brains."
The new research has also shown that the small calcium molecule is the messenger in the communication.
The researchers have found a new calcium receptor on immune cells, acting as a mailbox to receive the parasite's orders for the cell to move.
"The neat thing is that the signal can be inhibited by regular blood pressure medicine.
When mice received the medicine, the spread of the parasite was inhibited," Barragan said.
"We do not want to say that blood pressure medicine can cure toxoplasmosis, but we have discovered a new signalling pathway in immune cells that is linked to their motility and that the parasite utilises in a very smart way.
"This helps us understand how the parasite is spread and disease occurs. In the longer term, it may help us develop targeted treatments for infection."