Archives for July 2010

When does sadness over the loss of a loved one tip over into clinical depression? How do you tell the difference between schizophrenia and some other form of psychosis?

Defining what is, and what isn't, mental illness is actually quite a hard thing to do. Inevitably it's a subjective process based on a careful and formalised assessment by health care professionals. To help, mental health practitioners have traditionally relied on a classification system developed by the American Psychiatric Association and known as the Diagnostic and Statistical Manual of Mental Health, or DSM.

This diagnostic "bible" is currently being re-drafted - the first substantial re-write since 1994. But researchers here are growing increasingly concerned at a series of changes they say are being made to widen existing categories, and the addition of a staggering range of new conditions.

Writing in the Journal of Mental Health, professor Til Wykes claims the new definitions are so broad that, in future, almost no one will qualify as normal. She's worried about the implications of branding so many people, and particularly children, as mentally ill.

"It shrinks the pool of normality to a puddle" Professor Wykes says, "there are going to be fewer people who won't end up with a diagnosis of mental illness".

One particularly Orwellian new addition is Psychosis Risk Syndrome, which singles out people who are thought to be at risk of developing a serious psychotic illness such as schizophrenia. Other new conditions under consideration include; mixed anxiety depression, binge eating and temper dysregulation disorder with dysphoria.

Dr Nick Callard, from the Biomedical Research Centre for Mental Health at the Maudsley NHS Foundation Trust, said labelling individuals as "at risk" of developing a disorder like schizophrenia was likely to cause a great deal of distress, and could expose them to social stigma and discrimination.

The researchers accuse the US authors of moving ahead of scientific progress in mental health, which has made relatively little headway over the last 16 years. The new edition of the DSM is due to appear in May 2013.

This is an amended version of the original blog

We know from the fossil record that dinosaurs and mammals must have co-existed for millions of years, and yet we know almost nothing about the nature of that relationship.

One clue, which appears to give mammals the upper hand, comes from the fossilised remains of a relatively large mammal, repenomamus robustus, discovered in 2005. It was found with the bones of a baby dinosaur in its stomach, and as the Smithsonian's Brian Switek speculates, it had apparently snacked on a young psittacosaurus shortly before it died.

Score it one-nil to the mammals. But as the old adage goes, one swallow doesn't make a summer, and most palaeontologists suspect the true nature of the relationship - given their size and dominance - is that predatory dinosaurs regularly preyed on mammals.

New evidence supporting this, more conventional predator-prey relationship, is emerging from the 80 million year old rocks of the Wahweap Formation in Utah's Grand Staircase National Monument. Reporting in the journal Geology a team lead by Professor Edward Simpson from Kutztown University has discovered evidence that predatory dinosaurs may have dug down into the soil to reach small burrowing mammals.

The first trace evidence shows scraping marks in the sandstone rocks made by a digging dinosaur, probably a deinonychus or Troodon. Below the claw marks numerous downward arching curves reveal the branching burrows of its intended victim - underground structures very similar to those made by small social mammals living today.

Based on the close association of these structures the researchers suggest a predatory dinosaur was trying to get at a mammal hiding in its burrow.

Commenting on the findings Brian Switek says "If you look carefully....it appears that the dinosaur was repeatedly sticking its foot into the hole and raking out sediment".

Behaviour that certainly appears consistent with a carnivore digging out its next meal. Life it seems - at least for early mammals in the Mesozoic - was nasty, brutish and short.

Tom Feilden adds...

Firstly can I say I'm very grateful for the comments posted on my original blog. I made an honest mistake, and appreciate the opportunity to explain what happened.

Correct attribution is an essential component of good journalism, especially in the field of science writing, where such a premium is put on the ownership of ideas and on accuracy and fact checking.

In writing my original blog I mistakenly assumed that Brian's article, posted on the Smithsonian website, had in fact been written by professor Edward L. Simpson, whose name (along with the other authors involved in the original research published in Geology) appears prominently at the bottom of the article. Hence my attribution of the ideas and quotes in the blog solely to professor Simpson.

Indeed if you try printing out Brian's blog (as I did) you will find that his strap-line falls off the bottom of the page entirely. I shouldn't have missed it, but I'm afraid I simply didn't spot Brian's name, and assumed the blog was a synopsis of the academic paper by the named authors, which I could therefore draw from.

As a result, in describing the research I subsequently used both the original paper and the blog as if they were a single source, reproducing the arguments and, inadvertently, attributing a direct quotation from Brian's blog to professor Edward L. Simpson. It was certainly never my intention to claim the ideas as my own.

Clearly I didn't look closely enough at the sourcing for the Smithsonian blog. It was an honest mistake, one we've acknowledged to the Smithsonian, but obviously it shouldn't have happened. It's been a salutary lesson for me, and I can only offer my sincere apologies.

Take a look at this startling - and unique - photograph. The first and only time the elusive Horton Plains slender loris has been caught on camera.

Now go and have a cup of tea.

Why tea? Well, tea is a big part of the reason why this cute, bug-eyed primate has been spotted only four times since 1937.

The clearance of tropical rainforest to make way for tea plantations has decimated and dissected its natural habitat, restricting the Horton Plains slender Loris to a series of isolated pockets covering just 1% of the land area of Sri Lanka.

When the species disappeared completely for 65 years between 1939 and 2002 it was presumed extinct.

A shy, nocturnal primate with short limbs, dense fur and large close-set eyes, the Horton Plains slender loris was never one for the limelight, but it took scientists from the Zoological Society of London more than 200 hours to catch this somewhat startled male on film.

"We are thrilled to have proved this loris's continuing existence" says ZSL Conservation Biologist Dr Craig Turner.

"The discovery improves our knowledge of the species, but we need to focus our efforts on the conservation and restoration of its habitat, the tropical forest where it still exists".

That may have more to do with the cup of steaming tea in your hand than anything conservationists can achieve on their own.

This unremarkable collection of shattered flints, fossilised plants and bone fragments may not look like much to you or me, but to the scientists who uncovered them on a beach in Norfolk it's a spectacular haul that suggests our earliest human ancestors may have arrived in Britain nearly a million years ago.

The discovery, published in the journal Nature, pushes back the arrival of our earliest human ancestors by more than 250,000 years, and throws up all sorts of interesting questions about who these people were, and how they lived.

Since the climate at that time was more like that of southern Scandinavia, it implies they may have been among the first humans to use fire to keep warm, and to wear skins and fur.

"These finds are by far the earliest known evidence of humans in Britain," according to the Natural History Museum's Professor Chris Stringer, a lead author on the paper.

"They have significant implications for our understanding of early human behaviour, as well as when and how our early forebears colonised Europe after their first departure from Africa".

Happisburgh on the Norfolk coast is more famous today as the site of a village that is rapidly being washed away by the North Sea. But 950,000 years ago the area would have been joined to the continent by a land bridge. These early humans would have lived cheek-by-jowl with sabre-toothed cats, primitive horses, mammoths and giant hyenas on the forest fringed floodplain of the ancient river Thames.

Until recently our earliest human ancestors were thought to have been confined to an area of Europe south of the Pyrenees and Alps.

While that line ebbed and flowed as the climate changed and ice ages advanced and retreated, it was assumed the colonisation of northern Europe came much later, with the earliest evidence for the occupation of Britain dating from sites like Boxgrove in Sussex at 500,000 years ago.

Then, in 2005, evidence from Pakefield in Suffolk pushed back the date for the human occupation of more northern latitudes to 700,000 years. The Happisburgh site extends the record even further, to somewhere between 800,000 and 1.2 million years.

"These new flint artefacts are incredibly important," says the British Museum's Dr Nick Ashton. "Not only are they much earlier than other finds, but they are associated with a unique array of environmental data that gives a clear picture of the vegetation and climate. This demonstrates early humans surviving in a climate cooler than that of the present day".

It's this climatic data - from the fossilised plants and pollen grains present in the deposits - that has lead scientists to speculate the happisburgh humans may have used fire, worn skins, and even constructed shelters to keep warm.

The winters in particular would have posed a severe challenge to anyone living in the open on this marshy floodplain.

Sadly, we know even less about the people who made the Happisburgh tools. Professor Chris Stringer believes it's possible they were related to the species Homo Antecessor, or pioneer man, found in deposits of similar antiquity in Spain.

But without the "holy grail" of fossilised human remains to study no one can say for sure.

The UK's nuclear legacy - the amount of radio active waste produced since the 1940's - amounts to nearly 500,000 cubic metres of high, low and medium grade radioactive material.

We've known for some time that the preferred option for dealing with this highly toxic stockpile (enough to fill the Albert Hall five times over) is deep geological storage in some sort of underground repository.

But what sort of repository? And, more importantly, where will it go?

We've moved closer to an answer this morning with the publication of a report from the Nuclear Decommissioning Authority.

Geological Disposal: Steps Towards Implementation sets out a comprehensive framework for the design and construction of a £4bn underground nuclear waste facility by 2040.

The scheme involves sealing nuclear waste in specially designed containers up to 1,000 metres below ground, and maintaining it there for up to a million years - the length of time it is likely to remain dangerously radioactive.

But first a suitable site has to be found, and here the key word is: "volunteerism".

The NDA has accepted that a decision of such lasting significance can only be taken with the consent of the local community. "All of our experience shows us that unless you can make volunteerism work you can't succeed," says the project Director Alun Ellis. "We have to be sensitive to their needs, listen to their concerns, and not try to railroad them".

So far only two local communities - Copeland and Allerdale Borough Councils in west Cumbria - have expressed an interest. Both areas will now be assessed for their geological suitability, before the crunch issue is addressed: what's in it for them?

Here the report makes interesting reading: "Any community that is ultimately chosen to host a geological disposal facility in the national interest will expect UK Government and the NDA to ensure that the project contributes to their further development and wellbeing".

In other words, a package of ongoing incentives - no one at the Authority is using the word bribes - will have to be hammered out between the volunteer community and the Government before the ground is cut.

If such a deal can be struck the NDA believes the design and construction phase could start as soon as 2025, with the finished UK Nuclear Waste Repository taking delivery of the first consignment of radioactive waste by 2040.

It's a sad fact that - despite the ingenuity of modern medical science - most treatments only stave off disease, preventing further deterioration or suppressing symptoms, rather than actually "curing" patients and restoring them to full health.

Regenerative medicine holds out the prospect of changing all that, revolutionising health care by exploiting the body's innate ability to heal itself, repairing or replacing tissues and organ function lost due to age, disease or congenital defects.

The idea springs from our increasingly sophisticated understanding of stem cells, and the basic biological and developmental processes going on in the body.

It's been known for some time that amphibians like newts and salamanders retain the ability to regenerate lost limbs. It's a trick shared with higher vertebrates - including humans - in the womb, but unlike salamanders we lose the knack of limb regeneration in later life: the genes responsible are still there, but they're dormant, or switched off.

Working at the Australian Regenerative Medicine Institute, Professor Nadia Rosenthal is trying to isolate the genetic mechanisms involved in tissue and organ generation and to work out how we might reactivate and control these processes.

"Regenerating entire human limbs is still a long way off" she says, "but what we're trying to do is to work out how these processes work in newts and salamanders and to apply the lessons to our own slightly less efficient regenerative capacities".

But the potential of regenerative medicine is not limited to developmental genetics. As anyone who's ever cut themselves or broken a bone knows, the human body retains some ability to repair itself through autologous, or adult, stem cells.

In her lab at Imperial College's Institute for Biomedical Engineering professor Molly Stevens is developing new materials - synthetic polymers and nanofibres - designed to stimulate and enhance this inherent regenerative capacity.

"Our approach is about restoring the body to its natural state. So what we're doing is designing materials that we can put into the body that will encourage stem cells to populate that material and to grow and form new tissue".

Another approach, being pioneered by Professor Andrea Brand at the Gurdon Institute in Cambridge, explores the biological processes that regulate the activity of adult stem cells in the brain.

Using fruit flies to model neurological function, Professor Brand is trying to reactivate quiescent neural stem cells. It's hoped the results could lead to new treatments for stroke and degenerative neural conditions like Alzheimer's and Parkinson's disease.

It's early days, but regenerative medicine at least holds out the prospect of being able to restore patients to full health. Something that has long been the ultimate goal of medical science.

Speaking on the programme this morning Professor Sir Ian Wilmut, who heads the MRC's Centre for Regenerative Medicine in Edinburgh, said we should be, "excited and optimistic about the opportunities being created in this area." But he warned that "We should be under no illusions that a lot of basic research will be required to take this knowledge through to the clinic. That effort must be underpinned by investment and funding for that research".