Features

Once he'd finished On the Origin of Species what did Darwin do with his vast collection of stuffed reptiles, mammals, fish and birds?

Have an office clear-out: or at least that's the amusing idea behind Darwin's Leftovers, a collection of stitched artworks created by over 60 knitters that's on display at the Oxford University Museum of Natural History [OUMNH] until 27 November. 

According to lead artist Liz Lancashire each element of the display celebrates a key part of Darwin's life and thinking: from the Galapagos iguanas and tortoises that showed how natural selection could cause new species to evolve to exploit new environments, to hummingbirds with their odd-shaped beaks giving an ultimate example of specialisation in nature.

She said: 'Charles Darwin had many hundreds of stuffed animals in his cupboard and I wanted to recreate some of the paraphernalia of his scientific collection and capture the day he had an office clear-out!'

All this month Liz will be helping the Museum run a series of workshops for both adults and children exploring the wide variety of 3D knitting and other textiles techniques used to create these curiosities.

It sounds like the perfect skill to learn in the run-up to Christmas: so if you see an iguana-shaped present nestling under your Christmas tree then you'll know you've got Mr Darwin to thank for it.

Darwin's Leftovers is on display in the main gallery of the Oxford University Museum of Natural History until 27 November

It’s the biggest problem in physics: the matter we can see in the universe accounts for just five per cent of the observed gravity that holds galaxies together.

The conventional explanation is that enormous amounts of invisible dark matter make up the missing 95 per cent but some have argued that it’s Einstein’s theory that’s at fault.

In a review in this week’s Science Pedro Ferreira of Oxford’s Department of Physics and Glenn Starkman of Case Western University assess how alternatives to dark matter are shaping up.

‘For over 25 years there has been a proposal that there is no dark matter, that we are simply misinterpreting the data and that what in fact is happening is that we don't understand gravity,’ Pedro tells me.

‘A rudimentary alternative was proposed in the early 80s but only recently were a few complete theories constructed that modify Einstein's theory of general relativity and that could in principle solve the dark matter problem without dark matter.’

Israeli physicist Mordehai Milgrom got the ball rolling in 1983 with a proposal that became known as modified Newtonian dynamics (MOND). Other alternatives build upon this work, such as Jacob Bekenstein’s TeVeS.

Pedro comments: ‘In the review we emphasize two main things. First of all that all of these theories seem to bring in something akin to dark matter through the back door. It is not that they need dark matter as well as modifications to gravity but that any attempt to modify gravity necessarily generates something dark.’

‘The second point is that, even though waters seem to be muddied, there should be observational tests which can distinguish between the two paradigms. By looking at how galaxies are distributed and how they distort any background light, it should be possible to pick out clues for modified gravity, i.e. to test whether Einstein was indeed correct.’

The hope is that galactic surveys, such as those carried out by the Joint Dark Energy Mission or Square Kilometre Array, will be able to see if the telltale signs predicted by these alternative theories really are out there.

Professor Pedro Ferreira is based at Oxford’s Department of Physics

A story earlier this week gave hope that a new method might be sensitive and reliable enough to help predict who will develop early memory problems that could later lead to dementia.

BBC News online reported that ‘memory and language tests can reliably reveal “hidden” early dementia’.

These tests aim to detect small slips in memory or slight loss of fluency in speech, and could help doctors monitor people coming to them with memory complaints.

It also could help researchers in this area, as Rebecca Wood, Chief Executive of the Alzheimer’s Research Trust, points out in the BBC Online piece: ‘Being able to spot and measure the initial stages of dementia is a crucial challenge if we are to improve drug testing and lay the groundwork for prevention trials.’

Oxford University researchers in the Oxford Project to Investigate Memory and Ageing (OPTIMA) were behind this study, funded by the Alzheimer's Research Trust and others. They gave a group of 241 healthy elderly volunteers regular tests that were designed to measure their use of language and their learning and memory abilities. They did this for a very long period of time: 20 years.

By following the volunteers for this length of time, the study, published in the journal Neurology, was able to show that the results of the Cambridge Cognitive Examination could reliably predict when a healthy elderly person was likely to develop mild cognitive impairment, a frequent precursor to dementia.

Professor David Smith of the Department of Physiology, Anatomy and Genetics, who led the study, explains: ‘In normal elderly people, those who perform very slightly below average in two cognitive tests (use of language, and learning and memory) are likely to convert to a state called ‘mild cognitive impairment’ sooner than those who score just above average on the tests. People with mild cognitive impairment have a high risk of developing Alzheimer’s disease later on.’

91 of the participants developed mild cognitive impairment during the study. Older people and those scoring lower on the language or memory tests were more likely to develop mild cognitive impairment more quickly.

‘These sensitive tests indicate that some changes that are marked in Alzheimer’s disease actually occur many years before the disease is apparent,’ says Professor Smith. ‘This implies that the disease process goes on for many years, but it also allows us to detect the disease long before it can be diagnosed.’

‘These simple tests could be used in memory clinics to help predict when elderly people will become cognitively impaired,’ he adds. It also raises the prospect that, should preventive methods be developed for dementia in the future, these tests could be used to identify who would benefit from early treatment.

At Halloween our thoughts turn to spiders and all things scary but how about spiders and dinosaurs?

Martin Brasier of Oxford University's Department of Earth Sciences has shown that amber found by amateur dinosaur hunters contains threads of the world's oldest spider webs - webs that were spun 140 million years ago.

The Oxford team report their results in the latest issue of the Journal of the Geological Society.

Martin comments: ‘This amber is very rare. It comes from the very base of the Cretaceous, which makes it one of the oldest ambers anywhere to have inclusions in it.'

Their evidence shows that the webs these threads belong to would have graced lush prehistoric forests frequented by dinosaurs such as Iguanadon and Allosaurus.

The web-spinners in question were closely related to the modern day orb-web, or garden spider. ‘These spiders are distinctive and leave little sticky droplets along the spider web threads to trap prey,’ Martin explains.

‘We actually have the sticky droplets preserved within the amber. These turn out to be the earliest webs that have ever been incorporated in the fossil record to our knowledge.'

The cobwebs were preserved in tree sap, possibly emitted by trees in response to fire damage, which then fossilised into amber. To reconstruct the webs, the scientists focused through the amber at 40 different positions, tracing it through the layers and then splicing it together again using a computer technique called confocal microscopy.

As well as the amber, there are several other types of deposit at the site which are showing remarkable levels of preservation, including silica and phosphate minerals.

Martin adds: 'It’s part of a larger project which is yielding rich rewards. There’s still a lot more to find, and we have even more exciting things to report in the near future.'

When, in 1985, Mark Moloney began to investigate how penicillin was formed he didn’t imagine that it would lead to advances in polymer chemistry and a new spin out firm employing 17 people.

As we’ve highlighted before Oxford was where vital research into the chemical, pharmacological and clinical development of penicillin took place (starting in the 1930s with Florey, Chain & Heatley).

But even by the 1980s quite how penicillin was formed chemically in its fungal source was still poorly understood, and the relevant chemical reactions were known to be highly complex and very unusual.

Mark, of Oxford University’s Department of Chemistry, tells me: ‘Our strategy to unravel this process involved working with highly reactive chemical entities called carbenes, which we used as a type of chemical ‘warhead’ to bind with, and allow subsequent identification of, the enzyme binding site which controlled the remarkable chemical reaction leading to the formation of penicillins.’

‘This was ‘pure’ academic research, with no obvious immediate use, and could never therefore be construed as ‘applied’.'

Polymer problem
The idea that this penicillin research might be relevant to polymers came from Bill Norris who had previously worked with Mark at Oxford’s Dyson Perrins Laboratory before moving to ICI Specialties.

Mark explains: ‘He rang me up and presented me with a problem he was working on relating to dye migration in plastics. This was a long-standing difficulty, well known in the industry, and relates to the instability of mixtures of polymers, resulting from their extreme chemical inertness and very different chemical properties.’

‘He suggested that my carbene reagents might provide a solution, in which we would use the ‘warhead’ properties to attach the relevant molecules of the materials together.’

They developed the idea and used an undergraduate project to test its practicality in the lab but Mark says that the notion that penicillin research might have an immediate impact on polymer chemistry ‘seemed ridiculous’ and that results from the initial work were unpromising.

‘But the germ of an idea had been sown, and the more we looked into it, the more the idea had potential; there had to be substantial value in simple chemical technology that permitted direct modification of a polymer surface.’

By 1998 they had established that it was possible to modify the surface of many organic polymers and inorganic materials to introduce colour using a simple chemical process. Mark describes this discovery as ‘unprecedented’:

‘Although we initially focused on colouring, principally because it gave an immediate initial indication of success, we had it in mind to design a process that would enable introduction of other types of functionality.’

Developing ideas
Convinced that the idea was worth pursuing, in 2003 Mark used funding from internal OU sources to appoint researcher Jon-Paul Griffiths, who rapidly developed a number of aspects of the idea, and retained complete ownership of the intellectual property. 

‘This funding enabled us to take the basic idea and demonstrate that it could be used to incorporate not only colour, but biocidal, fluorescent, adhesive, and pH sensing effects onto polymers which would normally be considered to be chemically too inert to allow such modification.’

‘We even surprised ourselves at what was possible; for example, we discovered that we could introduce fluorescence onto diamond, and have more recently demonstrated that we can impart aqueous and organic dispersability onto C60, carbon nanoparticles and nanotubes.’ 

After patenting some of this work Mark and colleagues sought to commercialise it through launching a spin out company, Oxford Advanced Surfaces (OAS), in July 2006 – with the help of Oxford University Innovation.

The new firm moved to facilities in the Centre for Innovation and Enterprise at Begbroke Science Park, just north of Oxford. The location was perfect, giving them access to the surface characterisation facilities of the Materials Department at Begbroke, but still keeping them close to the Department of Chemistry.

In 2007 OAS Group plc was listed on AIM, and now employs 17 people. The firm is currently developing the carbene technology, trademarked as ONTO, both in-house and in collaboration with companies in fields as diverse as electronics to commodity goods and healthcare. 

Looking ahead, Mark comments: ‘We are satisfied that our technology is robust and delivers measurable effects against commercially relevant objectives, but the challenge now is to demonstrate that it can be done within the financial constraints imposed by the market.’

In October 2009 Mark Moloney received THE's Serendipity Award for his work, an award that celebrates the unexpected outcomes of research.