Professor Alain Goriely is Professor of Mathematical modelling at Oxford University’s Mathematical Institute and founder of the International Brain Mechanics and Trauma Lab (IBMTL). He talks to ScienceBlog about the key findings from his recently published work ‘Dimensional, Geometrical and Physical Constraints in Skull Growth’, and how geometry and mathematical modelling can help us to understand the mechanics of the brain.
In 2013, together with Prof. Antoine Jérusalem from the Engineering Department, I opened the International Brain Mechanics and Trauma Lab (IBMTL) here in Oxford. IBMTL is a network of people interested in the many and varied problems of brain mechanics and morphogenesis. As part of the launch, in true Oxford style, the team organised a workshop, where I got talking to Jayaratnam Jayamohan, aka Jay Jay, a brilliant paediatric neurosurgeon at the John Radcliffe Hospital, in Oxford, whose work has featured in BBC documentaries. Jay Jay routinely performs surgery on children to rectify abnormal skull growth (so-called “craniosynostosis”). The variety of shapes and intricacy of growth processes that he talked about immediately captured my imagination. He explained that much has been learnt about this process from a genetic and biochemical perspective and the world expert, Prof. Andrew O. M. Wilkie, also happened to be working in Oxford. I decided to pay him a visit.
Andrew Wilkie has done ground-breaking work in identifying genetic mutations behind rare craniofacial malformations and, in my discussions with him, he was particularly helpful in explaining the mechanisms underlying this fascinating process. Yet, surprisingly, I found that very little was known about the physics and bio-mechanics of the problem. And when I was told that the problem of understanding the formation of these shapes was probably too complex to be studied using mathematical modelling tools, I realised I had a challenge I couldn’t possibly resist. What’s more I had the perfect partner in Prof. Ellen Kuhl at Stanford University. Ellen is an expert in biomechanical modelling and has developed state-of-the-art computational techniques to simulate the growth of biological tissues. We had much to work on and still do.
The growth of the skull in harmony with the brain is an extremely complex morphogenetic process. As the brain grows, the skull must grow in response to accommodate extra volume while providing a tight fit. These are very different growth processes. The extremely soft brain increases in volume while the extremely hard bone must increase in surface area. Using mathematical modelling, we set out to understand how this process takes place.
In the spirit of mathematical modelling, we started with a very simple question: ‘how would a given shape remain invariant during such growth processes?’ We know that the skull grows through two different processes: first, accretion along the suture lines (transforming soft cartilage into bone) and second, remodelling of the shape to change locally the curvature. Without remodelling, the shape cannot remain invariant. Since surface addition mostly happens along a line, a point with initial high curvature away from this line would remain highly curved unless a second process enabled the reduction of the curvature so that the shape remains a dilation of the original shape.
Using dimensional arguments, we concluded that the three processes (volume growth, line growth, and remodelling) are inter-dependent and must necessarily be tightly regulated. But how is this process synchronized? Since the information about the shape is global, the cues that trigger the growth process must be physical as has been suggested in the biological literature. By simple physical estimates of pressure, stresses and strains, our analysis further identified strain as the main biophysical regulator of this growth process.
At this point, a natural question to ask is ‘what happens when this process is disrupted?’ We decided to extract the fundamental elements of this growth process by looking at the evolution of a semi-ellipsoid (an elongated half-sphere) divided into a number of patches representing the various bones, fontanelles (soft spots), and sutures of the cranial vault. Normal growth process is obtained by allowing the bones to grow along the suture lines. However, we decided to perturb the system by fusing some of the suture lines early as happens during craniosynostosis. To our great surprise, the various shapes obtained mirrored the ones found in craniosynostosis. We showed that idealised geometries produce good agreement between numerically predicted and clinically observed cephalic indices (defined as the cranial vault’s width by its length) as well as excellent qualitative consistency in skull shape – in other words the model worked. The particular geometric role in the relative arrangement of the early cranial vault bones and the sutures appear clearly in our models. What is truly remarkable is that, despite the extreme complexity of the underlying system, the shapes developed in these pathologies seem to be dictated mostly by geometry and mechanics.
What's next? Our models are, of course, extremely simple from a biological standpoint. However, they can be easily coupled to biochemical processes in order to analyse several open questions in morphogenesis and clinical practice, such as the impact of different bone growth rates, the relative magnitude of mechanical and biochemical stimuli during normal skull growth, and the optimal dimensions of surgically re-opened sutures. Our mechanics-based model is also a tool to explore fundamental questions in developmental biology associated with the universality and optimality of cranial design in the evolution of mammalian skulls. These questions were raised exactly a century ago by d’Arcy Thompson in his seminal book ‘On Growth and Form’ and we now have the mathematical and computational tools to answer them. We are only at the beginning.
From the books we read, to the films and programmes we watch, and the theatre productions we attend, the arts’ have the power to get us all talking and thinking. But can they actually influence our perceptions of real issues?
The study set out to see if watching a play about the teenage brain, could impact how people felt about criminal responsibility. Because of the nature of the production, perceptions of offences committed by children under the age of sixteen were of particular interest.
From hormonal outbursts, to rash decisions and bouts of expression, it is well known that young people go through a lot of behavioural changes during adolescence. How much people understand that it is the brain’s natural mechanisms that cause these changes, as it develops, with age, is less well known. Produced in collaboration with neuroscientists at UCL, and teenage performers, ‘Brainstorm’ supports this understanding, communicating complex scientific knowledge and highlighting the various developmental changes that adolescents experience as their brains change.
An adult might find it easier to resist the urge to lash out, or respond to confrontation. But, for a teenager, that impulse is likely to feel stronger and much harder to resist. Their brains naturally respond to impulses, and the part of their brain that would ordinarily resist them is still developing, and therefore much weaker.
When considered in the context of criminality, if people are not truly responsible for their brains and the brain influences whether or not we offend, it could be argued that teenage offenders may not be truly responsible for their crimes.
‘Brainstorm’ audience members were asked to complete a survey of questions, either before or after watching the play. A total of 728 respondents shared their views on four questions, framed around three key issues; the age of criminal responsibility, moral responsibility and the likelihood of reoffending.
Results revealed that the play did affect audience attitudes to crime, and particularly youth crime. After watching the play, participants perceived a hypothetical young offender as less likely to reoffend than an adult offender. They also perceived the young, but not adult offender, as less morally responsible for their actions, especially those who had committed a first time offence.
Robert Blakey, the study’s author and a DPhil student at Oxford’s Centre for Criminology, said: ‘We all have this feeling that when we resist an impulse, we are deciding to resist that impulse – not our brain, but this mental sense of me that makes decisions free from biological constraints. But neuroscience suggests this just isn’t true. We are always affected by our brain – in every decision that we make.
‘After learning about the science of the teenage brain, the public may change how it views teenage offenders. And that’s exactly what happened after these theatre goers watched 'Brainstorm'. They changed how they viewed teenage offenders.
‘In the future, I expect neuroscience to change our priorities, so that we think more about why teenagers offend, and how we can help teenagers choose the right path, rather than ignoring the cause and closing the cell door completely’.
The full study is available to download from the online journal Frontiers in Psychology
Learn more about the teenage brain in this Oxford Sparks animation:
Miguel Pereira Santaella, Research Associate at the Oxford University Department of Physics, discusses his newly published work observing never before seen water transitions in space. He breaks down how the discovery will help scientists to answer big planetary questions and build a more accurate understanding of the universe.
From clouds to rivers, and glaciers to oceans, water is everywhere on Earth. What’s less well-known, though, is how abundant the molecule is in space.
Unlike on Earth, most of the water in space takes either the form of vapour or forms ice mantles stuck to interstellar dust grains. This is because the extremely low density of interstellar space - which is trillions of times lower than air, prevents the formation of liquid water. the birth of star formations can tell us about how the Universe behaves. But, since the only way to study them in such dust obscured environments is through the infrared light, detecting water transitions capable of detecting this light, is of vital importance.
Observing the birth of star formations can tell us a great deal about how the Universe behaves. But, since the only way to study these events in such dust obscured environments is through the infrared light, detecting water transitions capable of capturing this light, is vital.
Water molecules experience fluctuating quantum energy levels. This activity allows us to observe them and is known as a water transition. The term refers to the best point for scientific observation, which is the exact wavelength at which water molecules go from one quantum state to another, emitting light and increasing their visibility as they do so.
The majority of these transitions are not very energetic so they appear in the far-infrared and sub-millimetre ranges of the electromagnetic spectrum, with tiny wavelengths (ranging from 50 μm and 1000 μm (1 mm)). Observing these water transitions from the ground is very difficult because the thick vapour in Earth’s atmosphere almost completely blocks the emission from view.
Improvements in technology and the development of super telescopes offer an increasing gateway to the universe, and planetary insights are moving at rapid pace. We can now detect water transitions in ways that we just could not before. They are best seen from telescopic observatories situated at high-altitude, in extremely dry sites. Such as, the Atacama Large Millimeter Array (ALMA), which is located in the Atacama desert (Chile) at 5000 m above sea level.
In our study published in Astronomy & Astrophysics, we used ALMA and detected the (670 μm) water transition in space, for the first time. The molecules were spotted in a nearby spiral galaxy (160 million light years away) at a point where the Universe is vastly expanded, and the atmosphere is therefore at its most transparent (red-shifted at 676 μm).
The water vapour emission in this galaxy originates at its core, in its nucleus, where most star formation takes place. To give you an idea of how enormous this galaxy is, the nucleus contains an equivalent amount of water 30 trillion times that of Earth’s oceans combined, and has a diameter 15 million times the distance from Earth to the Sun.
So what sets this water transition apart from others observed in the past? Our analysis revealed that these water molecules intensify their rate of emission when they come into contact with infrared light photons. This increase in activity makes it easier for scientists to observe them. Water molecules are most attracted to photons with specific wavelengths of 79 and 132 μm, which, when absorbed, strengthen the transition’s outline, therefore increasing its visibility. For this reason, this specific water transition has the ability to show us the intensity of the infrared light in the nucleus of galaxies, at spatial scales much smaller than those allowed by direct infrared observations.
Infrared light is produced during events like the growth of supermassive black holes or extreme bursts of star-formation. These events usually occur in extremely dust obscured environments where the optical light is almost completely absorbed by dust grains. The energy absorbed by the grains increases their temperature and they begin to emit thermal radiation in the infrared. Capturing these events can tell us a great deal about how the Universe behaves, so detecting water transitions that can capture this infrared light, is vital.
Moving forward we plan to observe this water transition in more galaxies where dust blocks all the optical light. This will reveal what hides behind these dust screens and help us to understand how galaxies evolve from star-forming spirals, like the Milky Way, to dead elliptical galaxies where no new stars are formed.
Merritt Moore has achieved what some would call ‘the impossible’: a career as a professional ballet dancer and as an academic quantum physicist. Having quite literally danced her PhD, she is just months’ away from completing her degree in quantum and laser physics. Immediately after graduation she will fly to China to perform at the Beijing National Theatre. Having danced since childhood, she sees great crossover between dance and quantum physics. Earlier this year she combined her passions, collaborating on a meditative science-influenced virtual reality experience called Zero Point Virtual Reality, which is currently running at the Barbican Theatre.
Scienceblog met with Merritt to learn more about fusing her talents and achieving success on her terms.
How did Zero Point Virtual Reality come about?
I have danced In a few of [choreographer] Darren Johnston’s productions, including his original Zero Point live performance in 2013. He takes a spiritual approach to his craft, and would often talk about ‘zero-point’ as a state of calm and zen. I introduced him to the concept of zero point energy as a physics phenomenon. A concept that means that there is always energy, even in empty vacuum, where one imagines no energy could exist. When the Barbican invited Darren to bring back his live production Zero Point, it was a natural progression to continue investigating the notion of ‘zero-point’, but this time using technology and dance. This led us to the virtual reality extension of the show.
We put our ideas together and collaborated with the Games and Visual Effects Lab at the University of Hertfordshire, and now we have a meditation experience running in 360° virtual reality (VR), at the Barbican. The end result is sublime and unique, and I hope people like it.
In what way did you draw on your physics background for the production?
It is an interactive, sensory experience, people walk from scene to scene, taking in the themes. There are quite a few quantum physics-based elements included. For example, in quantum mechanics the systems are constantly evolving, but the minute you try to measure or interfere with them, they stop. We’ve incorporated this by having a moving rock that only moves when you are not looking at it. The approach is very subtle, and a non-scientist probably wouldn’t spot the connection, but it is there. Hopefully it will trigger people to think in a different way.
I’ve always felt that physics and dance have a lot in common. I have a confession that I sometimes read more physics papers when I am preparing for dance meetings than I do for my own research. It inspires me and makes me think about a process, and how I would explain it to someone without all the lingo and technical terminology that we scientists are so used to. Sometimes we ourselves get so lost in jargon, that we forget what things mean, so how can we expect anyone else to understand? The dance community are not scientists, so they ask a lot of ‘why’ questions, which can really throw you. In science, people rarely ask why? They work from facts, so it just is the way it is. It challenges you to think differently and try harder to break things down.
How would you like people to react to it?
The main purpose is to inspire people to view ideas from a different perspective, (literally since with VR you can be placed anywhere). I don’t want to just regurgitate facts, I want to encourage people’s curiosity.
When did you discover your passions for science and dance?
I started dancing when I was 13, which is considered middle-aged in the dance world - most people start as toddlers. Before I discovered dance I was just a girl who loved maths and solving puzzles. I didn’t talk until I was three, so I would communicate through my puzzles. Then I found dance, and was just like ‘this sits in the box of non-verbal activities, I dig this!’ And then, when I found physics, I felt the same way.
You are in your final year at Oxford, what is your thesis investigating?
I am currently working to create large entangled states of light. The more photons - particles of light, you use, the harder it becomes to maintain their quantum properties. Adding more photons makes the whole project more vulnerable to noise, which can destroy their natural state. Understanding how photons behave when you interfere with them can help scientists to explore quantum mechanics phenomena.
What drew you to physics?
I love the creativity. Visualising and probing problems that have never been solved before requires a lot of imagination. Often it is mind-bending, and makes no sense. Quantum mechanics is so bizarre - even though the experiment proves again and again that it works, it still makes my head spin.
How do you manage two successful careers in two different fields?
I’ve retired from dance about ten times, burnt my ballet shoes and tried to get so out of shape I would never dance again, but I always come back to it. I honestly never thought I would be a professional dancer. A dance career was a no-go in my family. But I always worked really hard, and achieved the grades I needed. So, when I got to [Harvard] university I was in a position to take a year off to dance with the Zurich Ballet Company. After that I returned for a year, and did the same again the following year, with the Boston Ballet. During the winter break at Oxford I performed with the English National Ballet, and right after leaving here, I will be in Beijing and then on to Edinburgh and Cuba.
Don’t get me wrong, it’s a struggle. I’ve worked a lot. Yes, there have been times that I have felt overwhelmed - when I have been in the lab for over 20 hours a day, sometimes literally sleeping there. But it has always been fun. I’ve realised doing both actually helps me to relax. It’s exercising a different part of the brain and the body and I need it.
What is your ultimate goal?
I haven’t figured out what my title will be yet, but I want to shatter all the stereotypes. The dream is to continue combining physics and dance. I want to dance for the next 10 years, become a principal dancer with a company, and still publish physics papers. I was inspired by the film Interstellar, which, for authenticity, channelled real science into its stunning visuals. Physicists shared insights on black holes and worm holes, and they were converted into special effects for the movie. If I’m able to do something like that, then life is complete.
Quantum physics is one of the more polarising sciences, why do you think that is?
Honestly I think physics in general is really under-sold at school. Classes tend to run the same way, with the standard set of problems that have been done so many times that they are probably online. It’s hard to inspire someone when they know that they can google and memorise the facts. That’s not learning. Technology has evolved so far that most of the information is already there. The asset that we bring to the table, as human beings, is creativity.
I think the way science is taught in schools is very isolating, and self-selecting. There is a misconception that science is technical and geeky, but it is collaborative, imaginative and so much fun.
Do you think that there are any unique challenges to being a woman in science?
I personally have never thought that there is anything that a man can do that a woman can’t. So I had always made a point of avoiding the “women in science” physics societies. I felt that by going, I was making a statement that I saw a difference. But, last year I went to my first meeting and it was amazing, and I thought ‘why didn’t I come sooner?’ I really valued the female camaraderie, and hearing people’s shared experiences. It made me realise that there are serious issues. The ratio of women to men in physics has barely budged in 40 years. You hear a lot of talk about change, but the numbers tell a different story.
Little things make a huge difference, particularly to young girls, and I had no idea. I was having lunch at a young STEM event, for girls aged 11-13. One girl causally looked up at a line-up of the old portraits and said ‘oh there’s a woman - I guess she’s the wife or something’, and the girl next to her said ‘Probably not important.’ My heart sank. I had heard of the Oxford Diversifying Portraiture initiative but never thought anything of it. I would shrug my shoulders and think ‘oh well, it’s history’. But listening to the girls’ highlighted how much, if we really care about getting more girls in science, every little change matters.
From drought concerns to political debate and international awareness activity, H₂O has become big news, with good reason. As quickly as the world’s population is rising, international water reserves are diminishing. Despite making up over 70% of the earth’s surface, the bulk of our water reserves are either oceans (97%), or locked up in ice (98% of fresh water supplies), and therefore undrinkable. These changing circumstances have left one in seven people worldwide - that’s over a billion - without access to clean drinking water.
Although near to the sea, countries in the Arabian Peninsula do not have access to rainfall or natural ground water resources and a water crisis is looming. Professor Nick Hankins, Associate Professor of Chemical Engineering at Oxford’s Department of Engineering Science talks to Science Blog, about his new research partnership with the University of Bahrain, developing cost-effective water treatment and desalination solutions.
What is sustainable water engineering?
I call my laboratory, the laboratory of sustainable water engineering, I think it explains the work better than chemical engineering. It is a way of thinking about a resource in terms of how we use it, store it, consume it, and recycle it, all of which are incredibly important in water treatment. Future research into sustainability is key to the future of our planet.
It’s often said that water is the new gold. Some dispute it, but the reality is there is a lot of water on this planet, and only a tiny amount of fresh surface water available. My research focuses on developing four key water treatment solutions: the supply of clean, potable drinking water e.g. low energy desalination of seawater, wastewater treatment, water reuse, and finally industrial process water treatment and recycling.
Sustainable water engineering is a way of thinking about a resource in terms of how we use it, store it, consume it, and recycle it. Future research into sustainability is key to the future of our planet.
To have enough fresh water we have to recycle it. It rains, it pours and then we recycle it. Sea water is a largely untapped resource that we need to utilise, but the current costs are just not sustainable.
Can you describe desalination?
Desalination is the process of removing all of the salt in seawater. Seawater also contains marine organisms, silt and other materials that reduce the purity of the water. These have to be stripped out to make it drinkable and/or useful to agriculture. It is a lot more expensive than treating rainfall or even wastewater, so any savings that you can make will make a big difference. It is particularly useful in countries that are near to the sea but do not have their own natural water resources, like Bahrain, Saudi Arabia and the Gulf region in general.
Does your research centre use any specific techniques?
Mining into the world’s seawater resource is key to future water sustainability. Thermal desalination was often used in this area, but the costs are just not sustainable. My research centre specialises in developing cost-effective, lower-energy intensive water treatment techniques.
Reverse osmosis is a popular water purification technology that uses a semipermeable membrane to remove ions, molecules, and larger particles from water under pressure. But I’ve been working on a technique called forward osmosis, which uses less energy. It uses the same principle, only the other way around. A ‘draw’ solution pulls out the water while the salt is trapped by a membrane. The draw agents - magnetic particles or large molecules - are then filtered out from the draw solution or removed by changing the temperature of the water. This allows drinkable water to be extracted, without the need to remove gunk or worry about fouling. It uses less energy and in the long term it could be a good solution to pre-treating the seawater.
The only way forward is to use renewable energy, or to find new ways of reducing the energy costs of treatment processes. Which is exactly the purpose of my research.
How is water treatment useful?
Water treatment has grown in international importance, particularly in the Gulf region. Now that oil resources are running out they are having to diversify economically, and find new ways to save money and conserve energy. As a result there is a lot of government interest in renewable energy, which is energy that is made from natural resources, like solar power, wind turbines and hydropower. Each area has its own challenges, but desalination is one of the most intensive uses for renewable energy.
How did the collaboration with the University of Bahrain (UoB) come about?
The University of Bahrain is in the process of setting up a centre for sustainability, which will focus on renewable energy research.
We recently entered into a four-year partnership with the UoB, which will support the centre to develop sustainable water resources. Our initial research collaboration will investigate ways to reduce the energy consumption associated with the pre-treatment of sea water, which is a necessary but energy-hungry first stage in desalination.
What are the overall project’s aims?
Developing solutions to producing water cost-effectively and sustainably in the future. Work might include irrigating the desert to see if you can grow crops there, or developing ‘seawater greenhouses’ in which desalination is combined with growing crops.
It’s a great opportunity for Oxford that also represents a progressive step forward for Bahrain politically. The country has strong historical links with the UK. They are keen to strengthen international links and work with academic centres of excellence like Oxford.
The clue is in the name, wastewater. We would be crazy not to recycle it. It is already happening in Singapore, where they drink recycled human wastewater. That is where the future is. We are going to have to start looking at our waste differently eventually, so why not now?
What interests you most about the project?
I am thrilled to be involved in an international collaboration where I think there will be a strong and immediate impact. It is also a very exciting opportunity for shared knowledge transfer, supporting a particular and very serious problem. Our findings can be applied straight away in Bahrain and will instantly make a difference to people’s lives.
When will work commence?
We are already up and running. A signing ceremony was held earlier this week at the UoB and attended by a number of state officials including the British Ambassador Simon Martin, the Regional Director of the British Council Alan Rutt and others from local industry.
The project funding includes two research positions, one working with me, in Oxford, and the other will be based at the UoB Sustainability Centre. The next step for us will be recruiting for those positions. We will work in parallel with the team at UoB and will hopefully start field work, conducting seawater analysis in October 2017.
Who will benefit from the research?
The Gulf regions share a common water supply challenge, so those countries will feel the initial benefits. But in the future the work could well be useful internationally and in the UK.
In general though, water desalination has wide benefits and could be useful even in wet countries with rainfall. Even in the UK there can be shortfalls in supply and regional droughts. There is already a desalination plant on the Thames Estuary at Bacton, which supplies clean water to the city of London, so there is scope for collaboration further down the line.
What are your long-term goals with the work?
The initial forecast is for four years, but the potential impact means it could, and hopefully will, run for much longer.
My research centre focuses on water treatment in general, answering questions like ’how do you turn rain water into clean drinking water?’ Another of my key research streams is the biological treatment of wastewater. Recycling wastewater is much more cost and energy-effective than desalination, but it is a concept that scares people. The world is on the brink of a devastating water crisis, so recycling the water used, and using less of it in general is really the only way forward.
The clue is in the name, wastewater. We would be crazy not to recycle it. It is already happening in Singapore, where they drink recycled human wastewater that is now cleaner than tap water. That is where the future is. We are going to have to start looking at our waste differently eventually, so why not now?