Mixed martial artist and computer science scholar Dr Rosi Sexton.

Mixed martial artist and computer science scholar Dr Rosi Sexton.

Many people who have just completed a PhD in theoretical computer science might be content with settling down to a life working at a top IT firm or high academia.

But not Dr Rosi Sexton MMA - she prefers to work in a cage.

The letters MMA after her name are not some spurious academic qualification; it stands for mixed martial artist.

Rosi Sexton is about to become a global star - and unsurprisingly her turn of fate has little to do with the careers advisers at Manchester University, where she earned her doctorate.

In the UK's cage-fighting scene, Dr Sexton has long been regarded as one of the top female fighters.

But now the mother from Manchester has signed a deal with a major American fighting league that will see at least three of her coming fights broadcast on cable television, bringing her to the attention of millions of cage fans worldwide and plunging her into the midst of one of the world's fastest growing sports.

Cage fighting - or mixed martial arts as the sport likes to be known - is one of the most brutal and popular forms of one-on-one combat.

Ultimate Fighting Championship, the industry's top league, has now become so popular it has overtaken boxing in the US in pay-per-view sales.

Recent tours to the UK managed to sell out both the O2 Arena in London and the Manchester Evening News Arena.

The fighting style itself is a physically gruelling mixture of wrestling and martial arts where almost anything goes.

Only biting, clawing, gouging, and low blows to the genitals are forbidden.

Unlike commercial wrestling leagues, there are no dummy punches or special clickers in the shoes to make it sound like a blow has been landed.

Like boxing, a winner defeats their opponent either by knocking them out or on judges' point-scoring.

Pinning down one's adversary also works.

The sport is overwhelmingly dominated by men who go by testosterone-fuelled stage names such as The Hammer and The Huntington Beach Bad Boy.

But the number of women's leagues is increases every year.

Even George Lucas's daughter, Amanda "Powerhouse" Lucas, 27, got in on the act recently, fighting her first bout in New Zealand.