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Pete Wilton | 07 Mar 14 | 0 comments
African elephants make a specific alarm call in response to the danger of humans, according to a new study of wild elephants in Kenya.
Researchers from Oxford University, Save the Elephants, and Disney's Animal Kingdom carried out a series of audio experiments in which recordings of the voices of the Samburu, a local tribe from North Kenya, were played to resting elephants. The elephants quickly reacted, becoming more vigilant and running away from the sound whilst emitting a distinctive low rumble.
When the team, having recorded this rumble [listen to the rumble here], played it back to a group of elephants they reacted in a similar way to the sound of the Samburu voices; running away and becoming very vigilant, perhaps searching for the potentially lethal threat of human hunters.
The new research, recently reported in PLOS ONE, builds on previous Oxford University research showing that elephants call 'bee-ware' and run away from the sound of angry bees. Whilst the 'bee' and 'human' rumbling alarm calls might sound similar to our ears there are important differences at low (infrasonic) frequencies that elephants can hear but humans can’t.
'Elephants appear to be able to manipulate their vocal tract (mouth, tongue, trunk and so on) to shape the sounds of their rumbles to make different alarm calls,' said Dr Lucy King of Save the Elephants and Oxford University who led the study with Dr Joseph Soltis, a bioacoustics expert from Disney's Animal Kingdom, and colleagues.
'We concede the possibility that these alarm calls are simply a by-product of elephants running away, that is, just an emotional response to the threat that other elephants pick up on,' Lucy tells me. 'On the other hand, we think it is also possible that the rumble alarms are akin to words in human language, and that elephants voluntarily and purposefully make those alarm calls to warn others about specific threats. Our research results here show that African elephant alarm calls can differentiate between two types of threat and reflect the level of urgency of that threat.'
[Read more after the break...]
Elephant 'human' alarm call rumble
Significantly, the reaction to the human alarm call included none of the head-shaking behaviour displayed by elephants hearing the bee alarm. When threatened by bees elephants shake their heads in an effort to knock the insects away as well as running – despite their thick hides adult elephants can be stung around their eyes or up their trunks, whilst calves could potentially be killed by a swarm of stinging bees as they have yet to develop a thick protective skin.
Lucy explains: 'Interestingly, the acoustic analysis done by Joseph Soltis at his Disney laboratory showed that the difference between the ''bee alarm rumble'' and the ''human alarm rumble'' is the same as a vowel-change in human language, which can change the meaning of words (think of ''boo'' and ''bee''). Elephants use similar vowel-like changes in their rumbles to differentiate the type of threat they experience, and so give specific warnings to other elephants who can decipher the sounds.'
This collaborative research on how elephants react to and communicate about honeybees and humans is being used to reduce human-elephant conflict in Kenya. Armed with the knowledge that elephants are afraid of bees, Lucy and Save the Elephants have built scores of 'beehive fences' around local farms that protect precious fields from crop-raiding elephants.
'In this way, local farmers can protect their families and livelihoods without direct conflict with elephants, and they can harvest the honey too for extra income,' says Lucy. 'Learning more about how elephants react to threats such as bees and humans will help us design strategies to reduce human-elephant conflict and protect people and elephants.'
Middle: Lucy King and Joseph Soltis film elephants reacting to Samburu voices. Above: elephants flee the sound of local people whilst emitting the telltale 'human' alarm call rumble.(Full story)
Jonathan Wood | 28 Feb 14 | 0 comments
Particular smells can be incredibly evocative and bring back very clear, vivid memories.
Maybe you find the smell of freshly baked apple pie is forever associated with warm memories of grandma's kitchen. Perhaps cut grass means long school holidays and endless football kickabouts. Or maybe catching the scent of certain medicines sees you revisit a bout of childhood illness.
What's remarkable about the power of these 'associative memories' – connecting sensory information and past experiences – is just how precise they are. How do we and other animals attach distinct memories to the millions of possible smells we encounter?
There's a clear advantage in doing so: accurately discriminating smells indicating dangers while making no mistakes in following those that are advantageous. But it's a huge information processing challenge.
Researchers at Oxford University's Centre for Neural Circuits and Behaviour have discovered that a key to forming distinct associative memories lies in how information from the senses is encoded in the brain.
Their study in fruit flies for the first time gives experimental confirmation of a theory put forward in the 1960s which suggested sensory information is encoded 'sparsely' in the brain.
The idea is that we have a huge population of nerve cells in many of our higher brain centres. But only a very few neurons fire in response to any particular sensation – be it smell, sound or vision. This would allow the brain to discriminate accurately between even very similar smells and sensations.
'This "sparse" coding means that neurons that respond to one odour don't overlap much with neurons that respond to other odours, which makes it easier for the brain to tell odours apart even if they are very similar,' explains Dr Andrew Lin, the lead author of the study published in Nature Neuroscience.
While previous studies have indicated that sensory information is encoded sparsely in the brain, there's been no evidence that this arrangement is beneficial to storing distinct memories and acting on them.
'Sparse coding has been observed in the brains of other organisms, and there are compelling theoretical arguments for its importance,' says Professor Gero Miesenböck, in whose laboratory the research was performed. 'But until now it hasn’t been possible experimentally to link sparse coding with behaviour.'
In their new work, the researchers demonstrated that if they interfered with the sparse coding in fruit flies – if they 'de-sparsened' odour representations in the neurons that store associative memories – the flies lost the ability to form distinct memories for similar smells.
The flies are normally able to discriminate between two very similar odours, learning to avoid one and head for the other. This is controlled by the neurons that store associative memories, called Kenyon cells. There's a separate nerve cell that acts as a control system to dampen down the activity the Kenyon cells, preventing too many of them from firing for any particular odour.
Dr Lin and colleagues showed that if this single nerve cell is blocked, the odour coding in Kenyon cells becomes less sparse and less able to discriminate between smells. The flies end up attaching the same memory to similar, yet different, odours.
Sparse coding does turn out to be important for sensory memories and our ability to act on them. Although the research was carried out in fruit flies, the scientists say sparse coding is likely to play a similar role in human memory.
Although sparse coding in the brain would seem to require much greater numbers of nerve cells, that cost appears to be worth it in being able to form distinct associative memories and act on them – thankfully. A life of experiences and memories is so much more full as a result.
For more info on the study, check out an excellent video on the research centre's website.(Full story)
Harry Dayantis | 27 Feb 14 | 0 comments
Chemistry probably isn't the first thing that comes to mind when you see skeletons at a museum, but an understanding of chemical reactions is essential to the work of the modern museum conservator.
Bethany Palumbo, Conservator for Life Collections in the Oxford University Museum of Natural History, used her chemical expertise to restore centuries-old whale bones for the Museum's recent reopening. The fruits of her team's hard work are now on display for all to see at the Museum, which reopened on 15 February to a staggering 30,000 visitors in the first week alone.
'Chemistry is a key element of conservation,' says Bethany. 'When I began the whale project in mid-2013, there had been no documented preparation of the skeletons for over a century – some of them have been at the Museum since 1860! We had to examine every inch of each whale and research the chemical composition of their bones and the oils they secrete before deciding how to proceed.'
Cleaning and preserving old bones is an intricate, technical task and each treatment must be tailored to the individual bone. Whale bones are especially challenging, as fatty oils slowly seep out over the years.
'When we began the project, there were thick layers of oxidised natural oils on many of the bones,' says Beth. 'This unsightly residue not only attracts dust and makes specimens look dirty, but it is also acidic in nature so can damage the bone. When we tested the oils, they had an acidity of pH4 – about the same as most acid rain. The density of the oil varied across the specimens, and the skulls tended to have more oil than other areas. Whales have a hollow area in front of their skulls filled with oil to focus sonar signals which seeps into the bones where it can remain for centuries after they die. Areas of bone, still saturated with this acidic oil, were in some cases crumbling with a gritty texture similar to wet sand.'
To remove the oily secretions, Bethany and her team brushed solutions of ammonia and purified water onto the bones. Ammonia is an alkaline chemical that works by a process known as saponification that converts fats into soap. Ammonia breaks fat molecules up into their glycerol and fatty acid elements to produce soluble salts and soap scum, which can simply be wiped or vacuumed from the surface. Concentrations of ammonia varied depending on the areas being treated.
'Particularly oily areas, such as the humpback skull needed to be treated with 10% ammonia, whereas we used only 5% for the other specimens,' explains Beth. 'We were careful when the solution came into contact with the cartilage, as this can also disintegrate with the alkaline ammonia solution. There's always a balance to strike with conservation, the treatment method you choose on should never cause more harm than good.'
As well as damaging the bones, the acidic oil also caused verdigris – the green pigment currently coating the Statue of Liberty – to blossom from the copper wires inside the bones used to support the skeletons. Verdigris can be build up over time when copper reacts with oxygen, and is rapidly accelerated by acids.
'The verdigris on the copper wires was exploding from the drilled holes in the bone, causing the wires to weaken and snap when we tried to remove them,' says Beth. 'We ended up using a soldering iron to heat the wire, softening the surrounding cartilage just enough for us to pull the wires out and then vacuum out any residues.
'We have now replaced the wires with stainless steel, which is strong and resistant to the environmental conditions of the museum. We considered alternative methods of putting the skeletons back together, but it made more sense to use the existing holes in the bones to avoid creating further damage to the skeletons.'
Almost paradoxically, the conditions of the Museum environment are actually rather bad for the bones. Ultraviolet sunlight from the glass ceiling destroys collagen in the bones, weakening their structure, and the fluctuating temperatures cause the bones to expand and shrink, weakening joints. Before the roof was repaired, the fluctuating humidity worsened this problem.
'Technically, the best place for these bones would be a cool, dark room,' explains Beth. 'There is often a trade-off between conservation and education, so we have to do the best we can to make sure the skeletons can cope when out in the open for all to see. The adhesives we select, for example, have to be able to withstand high heats and fluctuating temperatures.'
Finally, when reconstructing the skeletons during the restoration process, the team tried to correct the anatomical features of the whales where possible.
'Dried cartilage will shrink over time, pulling the bones into unnatural positions,' says Beth. 'We corrected this by repositioning bones with new wires where possible, but some areas were just too fragile. Also, since we only had six months to complete the project, we simply didn't have the time to correct everything. There are some parts of the fins and ribcages that remain slightly incorrect, which is frustrating, but the skeletons are still far more anatomically correct than when we started.
'After a thorough restoration project, I think our whales will have a few good decades more on display. I'm extremely proud of what my team achieved in a short space of time, and hope that visitors will continue to enjoy seeing the whales in the Museum for years to come.'(Full story)
Pete Wilton | 13 Feb 14 | 0 comments
In the battle against the mosquitoes that carry deadly human diseases scientists are recruiting a new ally: a genetic enemy within the mosquito's DNA.
These new recruits are homing endonuclease genes (HEGs), 'selfish' genetic elements that have a better than normal chance of being passed on between generations despite being potentially harmful to an individual.
HEGs can recognise and 'cut' a short sequence of DNA on one of a pair of chromosomes, then fool an organism's repair mechanism into copying the HEG across onto the other chromosome. The HEG gets inserted within the 'cut' sequence of 'normal' DNA whilst the 'cut' is repaired. It is this 'drive' that makes HEGs particularly interesting for disrupting DNA and hence mosquito control.
Crucially HEGs can be used to recognise and disrupt a bit of DNA that really matters – that is important for an individual mosquito to survive from egg to adult.
'HEGs occur naturally in some simple organisms, such as single-celled fungi, and have been artificially inserted into the genomes of other organisms, notably the mosquito species, Anopheles gambiae, that is the main vector of human malaria,' explains Mike Bonsall of Oxford University's Department of Zoology.
'They can be used either to suppress mosquito populations by altering the inheritance patterns of genes (for example genes that affect survival) or to alter the genetic structure of mosquito populations by driving genes that alter the key mosquito characteristics (such as the ability to transmit a pathogen).'
Such a genetic approach could be an important weapon against diseases like malaria, which is responsible for up to 1.6 million deaths a year worldwide, by reducing the numbers of disease-carrying adult female mosquitoes in a local area to such a level that there aren’t enough to support and pass on the infection to humans.
But HEGs are not simply 'genetic homing missiles' that kill mosquitoes: such selfish genetic elements have to spread, the individuals carrying them have to compete, and populations respond and change.
'While it is necessary to understand the population genetics and patterns of HEG inheritance, the effectiveness of HEGs requires an understanding of both the ecology and genetics. The population dynamics and ecology determine how individuals in a population compete, grow and disperse,' Nina Alphey of Oxford University's Department of Zoology tells me.
'Population genetics might predict that a HEG that reduces survival will naturally spread through a population, but that does not necessarily mean the population will be reduced enough to significantly alter disease transmission. Simply knowing the genetics is not quite enough.'
To explore how interactions between ecology and genetics can influence the effectiveness of HEG-based mosquito control Mike and Nina developed a mathematical model as part of a BBSRC-funded project. They report their findings this week in Journal of the Royal Society Interface.
'One significant finding from our work is that we show that the type of competition affects the outcome of HEG-based control. If competition is particularly strong, alterations in early larval survival could lead to an increase in mosquito population size, rather than its decline,' Mike explains. 'This occurs as the population is 'freed' from its natural ecological control – which in mosquitoes occurs in the late-larval stage.
'We also showed that if a HEG does not just reduce the mosquito's survival, but also changes how that mosquito fares during the larval competition, it could achieve a better reduction in mosquito numbers than an identical HEG that simply reduced survival. The effects of a HEG that affects both survival and timing of competition would need to be carefully monitored to ensure that population suppression is achieved.'
Whilst with larger animals it might be possible to monitor individuals as a way of understanding population dynamics this is impractical for populations of thousands of insects, such as mosquitoes, linked to tiny patches of habitat – a small pond or even just a container of water.
Mathematical models are the only practical way of studying the links between genetics and ecology and identifying potential pitfalls in any genetic insect control approach – such as HEGs acting early in an insect's lifecycle being less effective than ones acting later on.
'We are working on extending our modelling approaches to understanding the control of mosquitoes by integrating economics and the cost-effectiveness of control programmes. This involves linking the costs of rearing modified mosquitoes, the epidemiology of the disease, the movement of people and mosquitoes and evaluating the public health benefits,' says Nina. The team have created an online game that highlights some of the issues faced by any control programme.
There are a lot of factors to consider in a future model: another variable is that in the wild populations compete with other species. For instance the malaria-carrying Anopheles gambiae mosquito may compete with various other species, and the dengue-carrying Aedes aegypti and the less competent Aedes albopictus compete with each other in some regions, so that reducing the numbers of one disease-carrying species could boost the numbers of another.
Mike tells me: 'We hope to work out when and where it might be appropriate to combine these insect control strategies with other disease implementation methods (such as vaccination programmes). Also thinking on how these insect control strategies can be used to control the spread of resistance to conventional control programmes is a new BBSRC project we have very recently started.'(Full story)
Harry Dayantis | 05 Feb 14 | 0 comments
When you think about evolution, 'survival of the fittest' is probably one of the first things that comes into your head. However, new research from Oxford University finds that the 'fittest' may never arrive in the first place and so aren’t around to survive.
By modelling populations over long timescales, the study showed that the 'fitness' of their traits was not the most important determinant of success. Instead, the most genetically available mutations dominated the changes in traits. The researchers found that the 'fittest' simply did not have time to be found, or to fix in the population over evolutionary timescales.
The findings suggest that life on Earth today may not have come about by 'survival of the fittest', but rather by the 'arrival of the frequent'. The study is published in the journal PLOS ONE and was funded by the Engineering and Physical Sciences Research Council.
I caught up with the study's lead author Dr Ard Louis, Reader in Theoretical Physics at Oxford University, to find out more.
OxSciBlog: How do your results challenge current popular theory?
Ard Louis: We are arguing that some biological traits may be found in nature not because they are fitter than other potential traits but simply because they are easier to find by evolution. Darwinian evolution proceeds in two steps. Firstly, there is variation: due to mutations, different members of a population may have differences in traits. Secondly, there is selection: if the variation in a trait allows an organism to have more viable offspring, to be 'fitter', then that trait will eventually come to dominate in the population. Traditional evolutionary theory focuses primarily on the work of natural selection. We are challenging this emphasis by claiming that strong biases in the rates at which traits can arrive through variation may direct evolution towards outcomes that are not simply the 'fittest'.
OSB: What can mathematical models tell us about biological processes?
AL: Evolution is perhaps the field of biology where mathematics has been the most successful. For example, it was mathematically trained biologists like R. Fisher, J.B.S. Haldane and S. Wright who first worked out how to combine Mendelian genetics, which Darwin didn’t know about, with Darwinian evolution. Today, very sophisticated population genetic calculations are routinely used, for example, to work out how cancer evolves in a patient’s body.
Of course one always needs to be careful because these models inevitably include simplifying assumptions in order to make them tractable. In our calculations we include difference in rates of the arrival of variation, something not traditionally taken into account in population genetics. But our models so far only apply to fairly simple examples of molecular evolution. Much more work is needed before we could claim that these effects are also important for more complex phenomena such as the evolution of animal behaviour.
OSB: How do your calculations match up with real-world observations?
AL: We predict, for example, that RNA molecules that are more robust to the effect of mutations should naturally arise from our 'arrival of the frequent' effect. RNA can act both as an information carrier and as a catalyst, and so is thought to be very important for the origin of life on earth. It has been known for some time that RNA found in nature is remarkably robust to mutations and we can now provide a population genetic explanation of this phenomenon.
OSB: How have field biologists reacted to these results?(Full story)
AL: On the one hand, biologists who work on evolution and development have not been so surprised because they have long argued that developmental processes can bias organisms to evolve in certain directions over others. Others have reacted with some caution, which is probably wise given the potentially far-reaching nature of our claims. I think we have raised a lot more questions that we have answered.
OSB: Did the results come as a surprise to you?
AL: On the one hand they didn't, in part because I have long been interested in Monte Carlo simulation techniques which have many parallels to evolution. There, biases in the arrival of variation are well known to affect outcomes. But I was very surprised to find that the biasing effect could be so enormously strong, making it robust to such a wide range of different evolutionary parameters.
OSB: How did your group come to study evolution?
AL: We specialise in statistical physics, and there are many beautiful parallels between evolutionary dynamics and processes in the everyday physical world. In my group we have worked for many years on self-assembly; how individual units can form well-defined composite objects without any external control. Biology is full of amazing self-assembled structures, and so we began asking: how do these structures evolve in the first place?
Harry Dayantis | 27 Jan 14 | 0 comments
Palaeobiologists at Oxford University have discovered a new fossil arthropod, christened Enalikter aphson, in 425-million-year-old rocks in Herefordshire. It belongs to an extinct group of marine-dwelling 'short-great-appendage' arthropods, Megacheira, defined by their claw-like front limbs.
Arthropods are a highly diverse family of invertebrates that include insects, arachnids and crustaceans, making up some 85 percent of all described animal species. The discovery and analysis of Enalikter aphson has given support to the notion that Megacheira came before the last common ancestor of all living arthropods in the tree of life. If correct, this would indicate that megacheirans were distant ancestors of all arthropods alive today.
Enalikter was just 2.4 centimetres long with a rounded rectangular head, no eyes and a curved, whip-like feature protruding from in front of its mouth that may have been used in feeding – for example to capture smaller marine invertebrates.
At the rear end of its stick-like body there were two pincer-like projections that were attached to a primitive ‘tail’, and which may have been used for defence against predators.The extinct arthropod had no hard shell but is nevertheless remarkably well preserved in a hard nodule of minerals comprised mainly of calcite. Professor Derek Siveter, lead author of the study from the Oxford University Museum of Natural History and Department of Earth Sciences, said: 'Enalikter aphson had a soft and flexible body so it is incredible that it survived. The nodule acted like a womb and kept the creature free from decay and destruction, which would normally have happened very quickly. It meant it was able to survive all the earth movements and history that have happened since.'
The researchers were able to reconstruct the specimen in 3D thanks to its perfect preservation in the nodule. The nodule was investigated by optical tomography, a technique that can be used to create digital reconstructions of 3D objects using a series of finely-spaced images. To reconstruct Enalikter, the researchers imaged sequential surfaces of the fossil, spaced a mere 20 microns – thousandths of a millimetre – apart. These numerous images were then edited on a computer, in places pixel by pixel, to identify true biological structures from background ‘noise’.
'In 3D it looks a bit like a tiny bottle brush, or even a Christmas tree. It is beautiful,' said Professor Siveter. 'It has provided us with exceptional data for the fossil record. Its soft body shell, or cuticle, is less than 10 microns thick. It was organic but has not decayed. That is amazing. Such exceptional preservation represents the jewel in the crown of palaeontology and provides so much more information than what does the typical shelly fossil record. It offers a rare window on the marine community back then.’
The newly-discovered animal, described in the journal Proceedings of the Royal Society B, lived so long ago that the UK would have been south of the Equator near where the Caribbean islands are now.
'It would have lived on the seabed in water possibly up to about 100 or 200 metres deep, at a time known as the Silurian, when invertebrates were just beginning to move onto land,' said Professor Siveter. 'It would have been a very warm, subtropical environment.'
The Herefordshire site where the fossil was discovered has been a real treasure trove for Professor Siveter and colleagues for almost twenty years, providing valuable clues about what life on Earth was like in ancient times.(Full story)
Harry Dayantis | 15 Jan 14 | 0 comments
Luminous galaxies far brighter than our Sun constantly collide to create new stars, but Oxford University research has now shown that star formation across the Universe dropped dramatically in the last five billion years.
The research, co-led at Oxford by Dr Dimitra Rigopoulou and Dr Georgios Magdis from the Department of Physics, showed that the rate of star formation in the Universe is around 100 times lower than it was five billion years ago. They also showed that some luminous galaxies could create stars on their own without colliding into other galaxies.
The findings, published in the Astrophysical Journal, suggest that most of the stars in our universe were born in a 'baby boom' period five to ten billion years ago. The observations were made using the European Space Agency's Herschel Space Observatory.
I asked lead author Dr Rigopoulou to explain the research and what it tells us about the birth of stars.
OxSciBlog: What has changed in the last five billion years?
Dimitra Rigopoulou: There is clear evidence that the galactic-scale physical processes that initiate the formation of stars in the most luminous galaxies in the Universe have changed. Locally, luminous galaxies that produce a large volume of stars are almost always associated with galaxy interactions or merging. When galaxies collide, large amounts of gas are driven into small, compact regions in the galaxies causing stars to form. This process results in a highly efficient conversion of gaseous raw materials into stars. However, we found that many galaxies were able to form stars without colliding a few billion years ago.
OSB: Why is this important?
DR: We know that the majority of the stars in our Universe were born in massive, luminous galaxies. Our results change our understanding about how stars were formed in these systems. Consequently, our view about the way the majority of stars formed in our Universe must change.
OSB: Why is it surprising that non-colliding disk galaxies can create stars?
DR: Normal disk galaxies are unperturbed systems that undergo a slow and steady evolution. So, by discovering normal disks with very high star formation rates we have uncovered a fundamental change in the galactic-scale process of star formation in the most efficient star-forming galaxies of our Universe.
OSB: What results surprised you the most and why?
DR: Over the last decade there have been various lines of evidence suggesting that in the early Universe around ten billion years ago, luminous galaxies were quite different from what we observe in the present day.
To our surprise, we found that this change already occurred less than five billion years ago, suggesting that the changes were very rapid and did not happen over long timescales. We measured ionised carbon, which is produced when the gas in the galaxy cools down and collapses initiating the formation of stars. The ionised carbon levels from luminous galaxies five billion years ago were very similar to those from ten billion years ago but completely different to today's galaxies. Something important must have happened to change galaxies' behaviour to what we see today.
OSB: Do we know why galaxy behaviour is changing?
DR: We think there are two main factors responsible for the change in the behaviour of galaxies: one is the amount of gas that is available to them and the other is the gas 'metallicity', the proportion of matter made up of chemical elements other than hydrogen and helium . As galaxies get older, they use up their gas to make stars so they run out of the raw material needed to create more stars. The availability of large gas reservoirs means that some galaxies can make stars efficiently without the need of interactions to trigger the star forming activity, as happens in local galaxies.Metallicity, on the other hand, is very closely related to star formation so a change in the specific make up of the gas can have a huge impact on the way star formation proceeds and hence affect a galaxy’s behaviour.
While our results have highlighted these important changes in the way galaxies form their stars as they turn older we now have to follow these leads and firmly establish these points of change in the fascinating lives of these luminous infrared galaxies.(Full story)
Harry Dayantis | 16 Dec 13 | 0 comments
What's behind the engines that keep planes in the air?
In a new animation launched today [watch it online here], Oxford University engineers take viewers on a tour around the modern jet engine, exploring the qualities that enable fast and efficient air travel.
The animation, 'Jet Plight', is the latest in a series of videos from Oxford Sparks, a web portal giving people access to some of the exciting science happening at Oxford University.
It follows the adventures of Ossie, a friendly green popsicle who has previously been on a spin around the brain, met a rogue planet and negotiated a volcano's plumbing system, as well as investigating heart attacks, the coldest things in the universe, and the Large Hadron Collider.
I caught up the project's scientific adviser, Professor Peter Ireland of Oxford University's Department of Engineering, to find out more about the science behind the animation.
OxSciBlog: What makes jet engines such a fascinating area of research?
Peter Ireland: Many things - for example, the way in which engines are designed to deal with extremes of pressure, temperature and rotational speeds. The gas flow inside the turbine needs to be precisely controlled and this means we need to understand the way it behaves. We use sophisticated computer models to predict these flows and experiments to understand the flow physics.
OSB: What made you decide to get involved with Oxford Sparks?
PI: I want people to see that engineering is an exciting, important subject and to encourage more schoolchildren to consider it as a career. There’s a real shortage of women going into engineering, so if this animation causes even one girl to consider a career in engineering then I’d consider it a success. There are fantastic opportunities for young people in this country, with a great demand for engineering graduates. Aerospace manufacturers are always looking to recruit new engineers to fulfil their ever-growing order books.
OSB: Why is it so important to make blades from a single crystal of metal?
PI: If you steadily try to stretch most metals, over time they extend slowly - or creep. Creep gets much easier at high temperatures, and the way a blacksmith works high temperature steel is a good example of how metal deformation gets easier with heating. Most metals are made of tiny individual crystals, and creep often occurs at the boundaries between crystals. Creep is reduced if the metal part is made of a single crystal.
OSB: What makes Oxford's turbine test facilities so special?
PI: Our research has focussed on understanding the way in which engine parts perform - especially the turbine. Over the last 40 years, we have perfected computer methods and experiments to understand and predict the performance of this amazing part of the engine. Our facilities allow us to study the heat transfer in great detail and to simulate real conditions using scale models. There are special equations in what we call ‘dimensionless groups', where certain parameters behave the same at all scales. For example, you could put an Airfix-size Concorde in a Mach 2 wind tunnel and see the same patterns of pressure and shock structures that you would see in the real thing – although you might need to strengthen the model if it’s made from thin plastic!
OSB: What impact might your group's work have on making 'greener' engines?
PI: We have helped to make the engine more fuel-efficient by reducing inefficiencies caused by aerodynamic losses and cooling air. The ultimate aim of most of our research is to reduce CO2 emissions from jet engines.
OSB: Do you expect to see any major changes in jet engines over the next few decades?(Full story)
PI: Yes. The engine architecture used for passenger Civil Aircraft, such as the Boeing 787 and Airbus 380, has been stable for many years. I think engine configuration will change significantly for future generations of aircraft. We can make engines more efficient by increasing the proportion of air passing through the propellers outside of the core jet intake, called the ‘bypass ratio’. However, these efficiency gains are reduced as we need to build ever-larger casings, called ‘nacelles’, around the propellers that add weight and drag. A new generation of engines called ‘open rotor’ are designed to work without needing nacelles, offering greatly improved efficiencies. I look forward to seeing these technologies develop in years to come.
Harry Dayantis | 29 Nov 13 | 0 comments
Reviving a gene which is 'turned down' after birth could be the key to treating Duchenne muscular dystrophy (DMD), an incurable muscle-wasting condition that affects one in every 3,500 boys.
Boys with DMD have difficulty walking between the ages of one and three and are likely to be in a wheelchair by age 12. Sadly, they rarely live past their twenties or thirties.
For the past 17 years, Professor Dame Kay Davies and Professor Steve Davies at Oxford University have been working on treatments for the condition, which is caused by a lack of the muscle protein, dystrophin.
In recent months they have found a number of new groups of molecules which can increase the levels of utrophin, a protein related to dystrophin. Greater levels of utrophin can make up for the lack of dystrophin to restore muscle function. They have worked with Isis Innovation, Oxford’s technology transfer arm, to strike a deal with Summit, a drug development company with a focus on DMD.
'Duchenne muscular dystrophy is a devastating muscle wasting disease for which there is no known cure,' said Professor Kay Davies. 'These boys all still have the utrophin gene – and that’s what we’re taking advantage of. In adult muscle, utrophin is present in very low amounts, and we aim to increase the amount to levels which will help protect the muscle in these boys.
'If this approach, called utrophin modulation, really works as we hope, we could treat these boys very early on, increase their quality of life and length of life. They would walk for longer.
'This is a disease that really needs effective treatment – it takes many families by surprise because of the high new mutation rate which occurs in dystrophin protein such that boys with no family history of the disease can be affected.'
The Oxford team have been working with Summit, an Oxford spin-out company, to develop their first drug for Duchenne Muscular Dystrophy, SMT C1100. In 2012, SMT C1100 successfully completed a Phase 1 trial which showed the drug could safely circulate through the bloodstreams of healthy volunteers. It is now about to enter clinical trials in people with DMD.
Professor Kay Davies said: 'In our ideal world the first molecule we developed with Summit plc, SMT C1100, will have a beneficial effect in these patients. But although SMT C1100 looks promising, we asked ourselves - can we find other drugs that might do even better?'
The new deal will see a research collaboration formed between the University of Oxford and Summit to further the development of the new set of molecules.
Professor Steve Davies said: 'We want to ensure that this utrophin modulation therapeutic approach has the best chance of success in the shortest time for treating Duchenne Muscular Dystrophy. We are delighted to join forces with Summit plc in developing, alongside first in class SMT C1100, these back-up and potentially best in class candidates.'
Tom Hockaday, Managing Director of Isis Innovation, said: 'Isis is delighted to support Professors Kay Davies and Steve Davies in this vital work. Having a number of potential drug candidates in development greatly increases the chances of reaching the ultimate goal, which is to successfully treat this incurable disease.'
Glyn Edwards, Chief Executive Officer at Summit, said: 'The alliance provides access to differentiated classes of utrophin modulators, potentially with new mechanisms, to complement our clinical candidate SMT C1100 while also establishing a strong drug pipeline for the future. Importantly, the alliance cements our long-term relationship with two scientific leaders at the University of Oxford.'(Full story)
Harry Dayantis | 27 Nov 13 | 0 comments
The magnificent plants at Oxford University's Botanic Garden and Harcourt Arboretum are always popular with visitors, but many people don't realise that they also have great scientific value.
Beautiful seasonal blooms conceal the secret lives of less conspicuous plants and trees used by university scientists for all kinds of research.
'Research plants are hiding in plain sight all over the place,' says Alison Foster, Senior Curator of the Botanic Garden and Arboretum. 'Many small flowers tucked away at ground level have been planted by biologists, and a lot of the trees are used in all kinds of research.'
When plant scientists want to see how certain plants, insects or birds cope outside of the lab, the Garden and Arboretum provide ideal natural environments. Last year, researchers from the Zoology Department collected aphids from plants in both collections.
'I don't think anyone could object to people taking a few aphids away!' says Alison. 'It's great to hear from researchers who want to do these sorts of studies, and it often helps us out too. In the aphid study, the researcher sent us a list of the plant types and aphid numbers which is useful information for any gardener!'
The same group went on to study whether or not aphids' resistance to fungus could be inherited maternally. They set up a pilot scheme, placing aphid colonies with clover plants across selected plots in the Arboretum. These were accompanied by water butts bearing brief explanations and QR codes so that visitors could learn about the science being done.
'The Arboretum provides an excellent natural research area, with plenty of space for ecological experiments like this,' says Alison. 'But we also get other requests which you might not expect – for example, we provided fresh charcoal from the Arboretum's burner to the Archaeology department so they could compare it with ancient charcoal for dating.
'We recently had a group of staff from the university go to Japan to collect seeds from Japanese trees. Now we're going to be growing plants from these seeds to enhance our collections and showcase some of the biodiversity research that is happening in the Department of Plant Sciences.'
The Arboretum also plays a role in undergraduate teaching, giving biology students a natural environment to pilot research projects. Many projects, such as rapid survey techniques, are good for the Arboretum as well.
'It's clearly of great value to us if students are helping us to map the plants around the site,' explains Alison. 'Eventually, we hope to plot the entire Arboretum tree-by-tree, and develop full soil profiles so we know exactly where to plant certain species. Students get real experience of conducting surveys and we get useful results: it's a win-win.'(Full story)