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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)
Harry Dayantis | 22 Nov 13 | 0 comments
Michael Faraday or Michael Flatley? Science or dance? The latest Science video competition shows that the two go hand in hand...
A creative video on sperm competition [above], which sees swimming cap-clad sperm chasing a water-borne egg through a lake, scooped top prize in Science magazine's 2013 Dance your PhD contest.
The film was created by Dr Cedric Tan from Oxford University's Department of Zoology, who has previously won the 2012 NESCent Evolution Video Contest and the Biology category of Science's 2011 Dance your PhD contest.
I caught up with Cedric to find out how he took his ideas from the lab to the lake...
OxSciBlog: Could you tell us a little more about the concepts shown in the film?
Cedric Tan: There were two main ideas in this film. First, a male invests more sperm in the females that have mated with his brother. This was an interesting finding in the red jungle fowl where females mate with multiple males, creating episodes of competition between sperm of different males. Second, the female ejects a higher proportion of sperm from the brother of the first male mate and favours the sperm of the non-brother, facilitating a higher fertility by the non-brother's sperm.
OSB: Why are non-brother sperm more successful, and are there evolutionary reasons for this?
CT: The non-brother sperm is probably more successful as a result of female preference and ejection of a larger proportion of sperm from any of the brothers. We are not sure why females behave as such but a probable reason is that the females are mating with the male that is different from the brothers in order to increase the genetic diversity of the offspring.
OSB: What challenges did you face trying to explain these concepts through dance?
CT: A major challenge is definitely the fact that dance is a non-spoken art and we had to use our bodies to convey the scientific idea. However, through movements inspired by chickens and sperm, we were able to illustrate sexual behaviour of the chicken and some interesting characteristics of sperm biology.
OSB: Could you tell us a bit about the accompanying music?
CT: The two original music and lyrics pieces were written by Dr Stuart Wigby, my former supervisor. The first piece 'Animal Love' is about the variety of sexual behaviour across different animal species. The second piece 'Scenester' is a piece about a girl who keeps changing her ways and males trying to keep up with her, which is especially apt for illustrating sperm competition.
OSB: How long did it take to plan, choreograph, shoot and edit?
CT: This idea was conceived last summer after I finished the previous video on 'Less Attractive Friends'. However I only started in June 2013 to plan, with the help of my Producer Sozos Michaelides and co-producer Kiyono Sekii. Choreography and training of the dancers was done with my co-choreographer Hannah Moore and lasted 4 weeks. Choreography came along quite readily as I was working simultaneously on my field experiments, in which I was deriving inspiration from the chickens and the sperm under the microscope. Hannah also worked very closely with me on synthesising sperm and chicken movements with sports actions.
After the intense training and for the following three weeks, the Director of Photography, Xinyang Hong, shot the dancing at various places, from Port Meadows to Hinksey Lake. I took about 3 weeks to edit the videos and that was a pain but looking at the outcome, I must say it was all worth it!
OSB: Do you have any plans for another video next year?
CT: Yes of course! It will sexier, stickier and sizeably bigger, and in the style of a musical. But the idea is a secret... I am already excited about creating this new piece!
OSB: Finally, how did you convince so many people to dress up as sperm and jump into a freezing lake?(Full story)
CT: It took lots of bribing with food. Kiyono also religiously brought flasks of hot drinks for the dancers every time we had pool/lake filming. As for the costume, many of the sperm complained a lot, I just had to buy more food.
Harry Dayantis | 12 Nov 13 | 0 comments
Over the last four years, solar cells made from materials called perovskites have reached efficiencies that other technologies took decades to achieve, but until recently no-one quite knew why.
Since perovskite was first used in 2009 to produce 3% efficient photovoltaic (PV) cells, scientists have rapidly developed the technology to achieve efficiencies of over 15%, overtaking other emerging solar technologies which have yet to break the 14% barrier.
Scientists at Oxford University, reporting in Science, have revealed that the secret to perovskites' success lies in a property known as the diffusion length, and worked out a way to make it ten times better.
'The diffusion length gives us an indication of how thick the photovoltaic (PV) film can be,' explains Sam Stranks, who led the discovery in Henry Snaith's group at Oxford University's Department of Physics. 'If the diffusion length is too low, you can only use thin films so the cell can't absorb much sunlight.'
So why is the diffusion length so important?
PV cells are made from two types of material, called p-type and n-type semiconductors. P-type materials mainly contain positively-charged 'holes' and n-type materials mainly contain negatively-charged electrons. They meet at a 'p–n junction', where the difference in charge creates an electric field.
The cells generate electricity when light particles (photons) collide with electrons, creating 'excited' electrons and holes. The electric field of the p–n junction guides excited electrons towards the n-side and holes towards the p-side. They are picked up by metal contacts, electrodes, which enable them to flow around the circuit to create an electric current.
'The diffusion length tells you the average distance that charge-carriers (electrons and holes) can travel before they recombine,' explains Sam. 'Recombination happens when excited electrons and holes meet, leaving behind a low-energy electron which has lost the energy it gained from the sunlight.
'If the diffusion length is less than the thickness of the material, most charge-carriers will recombine before they reach the electrodes so you only get low currents. You want a diffusion length that is two to three times as long as the thickness to collect almost all of the charges.'
The thickness of a solar cell is always a compromise – if they're too thin they won't absorb much light, but if they're too thick the charge carriers inside won't be able to travel through. Longer diffusion lengths allow for more efficient cells overall, as they can be made thicker without losing as many charge carriers. Scientists can get around this by arranging cells into complex structures called 'mesostructures', but this is a time-consuming and complicated process which has yet to be proven commercially.
Previously, researchers were able to get mesostructured perovskite cells to 15% efficiency, using a perovskite compound with a diffusion length of around 100 nanometres (nm). But by adding chloride ions to the mix, Henry's group achieved diffusion lengths over 1000nm. These improved cells can reach 15% efficiency without the need for complex structures, making them cheaper and easier to produce.
'Being able to make 15% efficient cells in simple, flat structures makes a huge difference. We've made hundreds just for research purposes, it's such an easy process. I expect we'll be seeing perovskite cells in commercial use within the next few years. They're incredibly cheap to make, have proven high efficiencies and are also semi-transparent. We can tune the colour too, so you could install them in aesthetically-pleasing ways in office windows.'
That perovskite cells are showing commercial potential after such a short time is a testament to their fantastic properties. We could well be seeing perovskite cells with efficiencies of 20-30% within the next few years, offering the same power as standard silicon-based cells at a fraction of the cost.
'Now is a truly exciting time to be working in the field,' says Sam. 'It's such a rapidly-emerging field, I expect to see it evolve even further over the next couple of years. What's incredible is that all of these advances have been made in academic environments so far, but it won't be long before industrial manufacturers start looking at perovskite cells as serious contenders.'(Full story)
Harry Dayantis | 05 Nov 13 | 0 comments
This week, scientists and engineers from Oxford University and around the world will start work on the final designs for the Square Kilometre Array (SKA), soon to become the world's largest and most sensitive radio telescope.
The SKA will cover a combined collecting area equivalent to a dish of about one square kilometre using thousands of dishes and millions of linked antennae spread across Australia and in Southern Africa. It will be able to detect radio waves more accurately and sensitively than ever before, helping to answer some of the biggest questions in physics and astronomy. These include questions about dark matter and dark energy, and perhaps even the biggest question of all: is humanity alone in the universe?
'After many years of planning and preparation it is very exciting that the SKA project is now moving in to the detailed design phase,' said Professor Michael Jones, principal investigator of SKA at Oxford. 'In a few years this amazing scientific instrument will no longer be the stuff of dreams but will start to become a reality.'
The Oxford team will lead the design of electronic systems to digitise and combine signals from millions of low-frequency antennae and allow the telescope to point in multiple directions at once. This will be done in collaboration with the Rutherford Appleton Laboratory along with partners from industry and other universities.
Oxford is also one of the key universities involved in preparation for the scientific exploitation of the SKA, with members on several of the SKA Science Working Groups. They will play a major role in the development of the signal processing systems that will search for pulsars, one of the SKA's key science goals, and in the development of software and high-performance computing systems for the project.(Full story)
Harry Dayantis | 28 Oct 13 | 0 comments
Proteins which reside in the membrane of cells play a key role in many biological processes and provide targets for more than half of current drug treatments. These membrane proteins are notoriously difficult to study in their natural environment, but scientists at the University of Oxford have now developed a technique to do just that, combining the use of sophisticated nanodiscs and mass spectrometers.
Mass spectrometry is a technique which allows scientists to probe molecular interactions. Using a high-tech 'nanoflow' system, molecules are transmitted into the instrument in charged water droplets, which then undergo evaporation releasing molecules into the gas phase of the mass spectrometer.
But membrane proteins are difficult to measure in this way, as they are hydrophobic: they don't dissolve in water. One way to overcome this problem is to mix them with detergents. Detergents work by surrounding insoluble substances with a water-friendly shell. Each detergent particle has two ends – the heads are attracted to water and the tails are attracted to insoluble regions of the membrane protein. The tails stick to the hydrophobic parts, leaving a shell of water-loving heads around the outside. The molecules can then easily dissolve in water.
Although detergents can be used to get membrane proteins to dissolve in water, these artificial chemicals can damage protein structures and do not faithfully mimic the natural environments in which they are normally found. The Oxford group, led by Professor Carol Robinson, has utilised a technique which allows them to study membrane protein structures by mass spectrometry from their natural environment. Their new method, published in Nature Methods, uses tiny disc-like structures made from molecules called lipids, as first author Dr Jonathan Hopper explains:
'Membrane proteins are naturally found in flat structures called lipid bilayers. Lipids are a bit like nature's detergents, in that they have water-loving heads and fat-loving tails. Lipid bilayers are made up of two sheets of lipids with their tails pointing inwards.
'The nanodiscs we use are made from lipids, the same material that membrane proteins occupy in the body. It's essentially as if you took a round cookie cutter to remove a section of the natural bilayer, so the conditions are just like they would be in the body. The discs are stabilised by wrapping a belt of proteins around them to keep the exposed lipid tails from the water.
'Aside from the nanodiscs, we actually got great results from 'bicelles', which are made in a similar way. The main difference is that instead of putting a belt of proteins around the edge, we plug the gap with short-chain lipids instead. This actually gives us much more control over the size and structure of the disc.'
These innovations enable researchers to study membrane protein structures using sophisticated mass spectrometry, in environments as close to the human body as possible.
'I am delighted that this has worked, it is completely unexpected given the difficulties we have had in the past in studying these complexes in lipidic environments,' says study leader Professor Carol Robinson. 'The breakthrough enables us to study membrane proteins in a natural environment for the first time. We believe this will have a great impact on structural biology approaches, and could in turn lead to better-designed drug treatments.'(Full story)
Jonathan Wood | 22 Oct 13 | 0 comments
'The world urgently needs new medicines for many diseases such as Alzheimer's, depression, diabetes and obesity,' says Professor Chas Bountra. 'Yet the pharmaceutical industry's success rate for generating truly novel medicines remains low, despite investing tens of billions of dollars.'
What's going wrong? Why can't we depend on the vast commercial pharma industry to deliver the new treatments we need? Professor Bountra is in the ideal position to ask. He came from the drug firm GSK to lead the Structural Genomics Consortium at Oxford University, a public-private partnership that bridges academia and industry and produces data that is directly relevant for coming up with new drugs.
'What the pharma industry has done is recruit some of the smartest people on the planet, invested tens of billions in technology and infrastructure, and acquired promising companies,' he says. 'It's not that industry is doing anything wrong. The problem is that it's so difficult. The fundamental bottleneck is our ability to identify new targets for drug discovery.'
Those working in this area talk about 'targets'. If you have a biological molecule, most often a protein, that you find is critical in a disease process in the body, this is a target.
It is a target because you can throw tens and hundreds of thousands of small chemical compounds at it and see which of these would-be drugs stick. You might come away with a handful of compounds that bind your target protein and block the disease process. Now you have somewhere to start, you have some candidate drugs against this disease.
You'll want to optimise the chemical compound, do toxicology checks, and there would be years of clinical trials to determine it was safe and beneficial. But the starting point turns out to be crucial. If you don't know enough about the target and the disease process it affects, you may waste billions of pounds, years of effort and expose patients to something that may have no medical benefit – or worse, find side effects you didn't know about.
Professor Bountra explains: 'There are around 22,000 different proteins in humans, any of which could be a target for a drug. There are hundreds of diseases and hundreds of subsets of diseases. What we can't do right now is say this protein will work in this subset of Alzheimer's patients.
'Pharma is extremely good at taking a candidate drug molecule through to market. None of us – and I include the whole global biomedical community in this – is good at selecting the right target for drug discovery.'
Peter Ratcliffe, Nuffield Professor of Medicine at Oxford University, is of exactly the same mind: 'It's almost self-evident that in starting drug development you need to start in the right place. We need to have the right molecular target.'
He is the director of the new Target Discovery Institute at Oxford University, an institute whose whole purpose is validating targets for drug discovery.
Researchers have just started moving into the TDI's impressive new building on the Old Road Campus. All clean lines, sharp angles and a glass frontage to guide you in, it brings the best biologists and chemists together with the latest genetic and cell biology technologies.
Modern biology research is delivering thousands of potential targets, Professor Ratcliffe says, but it is currently hard or impossible for scientists in pharma to know which are the most promising to pursue for new drugs. He believes that at least a portion of academic research should be more aligned to what industry needs to take things forward.
One of the examples Professor Ratcliffe gives is a set of enzymes called histone demethylases. These are involved in switching genes on and off in cells, and drugs targeting these proteins may be useful in cancer and inflammatory disease. But this work is still at a relatively early stage and there is a lot to be done to determine the range of effects that blocking these enzymes can have, and whether discrete medical benefits can be achieved. That's where the interest of the TDI comes in.
Forging successful partnerships between academia and industry is exactly what Professor Bountra has done at the SGC. This not-for-profit group, which with academic and industry partners worldwide determines the three-dimensional structures of proteins of importance to human health, places the data in the public domain, open and free to all. Knowing the structure of a protein is important in finding candidate drugs that bind this target.
More recently, the SGC began working further along the drug discovery chain in coming up with novel chemical compounds that block target proteins. Again the data and reagents are openly available to allow anyone to investigate them. Some novel drug compounds are already being taken forward by new biotech companies.
'We need to pool the strengths of academia and industry,' Professor Bountra believes, 'to create a more efficient, more flexible way of discovering new drugs. It is only by pooling resources and by working with the best people that we can hope to reduce costs and reduce risks in this very difficult task of discovering new drugs.'
Professor Ratcliffe adds: 'The failure of drug candidates at a late stage in large-scale trials is reasonably held to be the thing killing the pharma industry. We have to secure the rationale for developing a drug in the first place, and we have to make sure we don't find untoward aspects at a late stage.'
Both professors believe that there is wider importance to the British economy, following many drug companies downsizing their research capacity in the UK. By making these projects in Oxford a success, it can bring in drug company investment, it can see new biotechnology companies spun off and help in retaining highly skilled people in this country, they say.
'I honestly think what is happening in Oxford is phenomenal,' says Professor Bountra. 'In the next one to two years, Oxford will be the academic drug discovery centre in the UK. What distinguishes Oxford is a culture that makes all of this work. We are all pulling in the same direction to help industry develop new medicines because society desperately needs new medicines.'
This article was originally published in Blueprint, the University's staff magazine.(Full story)
Pete Wilton | 03 Oct 13 | 0 comments
The health of the ocean is spiralling downwards far more rapidly than previously thought, according to a new review of marine science.
The latest results from the International Programme on the State of the Ocean (IPSO) suggest that pollution and overfishing are compromising the ocean's ability to absorb excess carbon dioxide (CO2) from the atmosphere. IPSO's scientific team warns that the oceans won't be able to shield us from accelerating climate change for much longer and that mass extinctions of some species may be inevitable.
'What the report points to is our lack of understanding of both the role of the ocean in taking up CO2 and the impact of human activity on marine ecosystems,' Alex Rogers of Oxford University's Department of Zoology, Scientific Director of IPSO, told me.
The findings are published in a set of five papers in the journal Marine Pollution Bulletin, the papers came out of meetings hosted at Somerville College, Oxford.
'Our research at Oxford is trying to fill in these gaps in our knowledge about how carbon is transported in the deep ocean,' Alex explains. 'We need more research in particular into the active processes taking place as animals migrate up and down in the ocean every day.
'Animals such as deep water fish will feed in surface waters at night, then migrate up to 1,600 metres back down into the deep. Animals like jellyfish repackage carbon ingested during feeding and excrete it as faecal pellets. We also see mass die-offs of deep sea animals – how this contributes to the carbon cycle, and how it might be affected by climate change, is very poorly understood.'
Alex highlights how estimates of the biomass from fish from the 'twilight zone' region (200-1000 metres deep) were recently found to be out by a factor of ten because it was not realised that these mesopelagic fish were actively avoiding underwater nets.
'That we can get the numbers out by this amount just demonstrates the poor level of knowledge about our oceans,' Alex comments.
Much more research is needed, he believes, if we are to understand how climate change both affects and is influenced by marine ecosystems.(Full story)
Pete Wilton | 27 Sep 13 | 0 comments
Travelling in flocks may make individual birds feel secure but it raises the question of who decides which route the group should take.
Mathematical models developed by scientists suggest that a simple set of rules can help flocks, swarms, and herds reach a collective decision about where to go. But investigating how this really works, especially with animal groups in flight, is extremely challenging.
A new study led by Oxford University scientists, reported in the Journal of the Royal Society Interface, has used the sort of high-resolution GPS technology normally reserved for extreme sports to look at how homing pigeons make decisions on the wing.
I asked lead author Benjamin Pettit of Oxford University's Department of Zoology about the research and what it tells us about the rules of the fly game…
OxSciBlog: What are the advantages of flying in a flock?
Benjamin Pettit: For pigeons, the main advantage of flying in a flock is to lower the risk of being eaten. Therefore pigeons in flocks need to coordinate their behaviour to stay together - something they have in common with many other animals. In addition to safety, there might be navigational advantages to flying as a flock. For example, when a flock of pigeons flies home together, the route they take will potentially combine navigational knowledge of many birds.
OSB: How are pigeons able to 'share information' in flight?
BP: Until now, nobody has directly measured how pigeons respond to each other's movements in flight, but from mathematical simulations we know that flocking can arise from simple rules based on visual cues, namely 'stay with the group,' 'avoid collisions,' and 'head in the same direction as those around you.'
If each bird is also paying attention to navigational cues, like familiar landmarks, then flocking rules will be effective at sharing information within the flock. What we do know from previous data on pigeon flocks is that there isn't always an equal, two-way exchange of information, and instead some pigeons have more of a leadership role within the flock.
OSB: How did you explore group navigation behaviour?
BP: We studied the simplest flocking scenario of two pigeons flying home together. Each pigeon had its own preferred homing route, which meant we could test how each pigeon's preference factored into the pair's route, and also find out how the group decision arises from the pigeons' momentary interactions during the flight.
The pigeons carried lightweight, high-resolution GPS loggers, which were actually designed for extreme sports. It was also the right technology for racing pigeons. Working together with mathematical biologists at Uppsala University in Sweden, we created a simulation based on the interaction rules that we inferred from the GPS data, which was a useful tool for studying pigeons' group decisions.
OSB: What did you find out about the rules governing this behaviour?
BP: Pigeons responded to each other by adjusting their speeds and making small turns, maintaining a close, side-by-side configuration most of the time. A pigeon was sensitive not only to its neighbour's position, as has been observed in fish schools, but also to the direction its neighbour was headed.
The flocking behaviour was stronger toward a neighbour in front than behind, which means that a faster pigeon that consistently gets in front has more influence over the pair's route. This simple leadership mechanism based on speed is something we investigated with a combination of the data and the simulation.
Our findings show how real bird flocks compare to the 'rules of motion' postulated in simulations over the past three decades.
OSB: How might your findings help us understand group navigation in other animals?
BP: First of all, we found that persistent leadership-follower relationships observed in nature are not necessarily something complicated that requires animals to recognise each other and assess each other's ability. The mechanism can be as simple as a difference in speed.
Second, we found some similarities with fish in terms of how flocks/schools are formed, but also some differences that are likely due to the biomechanics of flight versus swimming.
The pairwise configuration of pigeons is similar to that observed in starling flocks. Rather than converging on a 'universal' flocking rule, different animal lineages have their own solutions for collective motion, which affect the shapes of schools, herds, and flocks. The particular interaction rules will also affect how information passes through these groups from one animal to another.(Full story)
Pete Wilton | 24 Sep 13 | 0 comments
In the race to describe all of Earth's species before they go extinct it has been suggested that one species that is thriving is taxonomists.
Taxonomists are the people responsible for describing, identifying, and naming species – so far they have described around two million species. This could involve trekking into the jungle to discover new plants and animals but more often means poring over samples in existing collections and databases to unearth previously undescribed species.
'Taxonomic data, knowledge about species, underpins nearly every aspect of environmental biology including conservation, extinction, and the world's biodiversity hotspots,' explains Robert Scotland of Oxford University's Department of Plant Sciences.
If you want to describe all Earth's species before they vanish then the question of the taxonomy community's capacity, and the speed with which they can discover new species, becomes very important.
Some recent studies looking at trends in extinction counted the number of authors on each taxonomic paper and concluded that there was an expanding workforce of taxonomists chasing an ever diminishing pool of undescribed species. 'These findings contradict the prevailing view that there are six million species on Earth remaining to be discovered by an ever diminishing number of taxonomists, the so called 'taxonomic impediment',' Robert comments.
To test whether taxonomists were really a booming or endangered species, and what this might mean for species discovery, Robert and colleagues from Exeter University and Kew Gardens analysed data on the discovery of new plant species. A report of the research is published in the journal New Phytologist.
'What we found was that from 1970 to 2011 taxonomic botanists described on average 1850 new flowering plants each year, identifying a total of 78,000 new species,' Robert tells me. 'But while this period saw the number of authors describing new species increased threefold, there was no evidence for an increase in the rate of discovery.
'One recent idea is that species are becoming more difficult to discover and more authors are subsequently required to put in more effort to describe the same number of new species. We found no evidence for this as the lag period between a specimen being collected and subsequently described as a new species has increased.'
The team's study showed that, far from running out of new species, there are still around 70,000 new species of flowering plant waiting to be discovered. So why are taxonomy authors multiplying?
To get some context the researchers analysed the number of authors on papers in other subjects including botany, geology and astronomy over a similar period, 1970-2013, and then compared them to the data on taxonomy authors.
'We found that the increase in authors on taxonomy papers was in fact fairly modest compared to the 'author inflation' in other subjects including botany,' Robert explains. 'Our data show for geology that there were 1.8 authors per paper in 1975 but this has risen to 4.8 in 2013, and for astronomy, 1.6 authors per paper in 1970, 8.4 in 2013, so a fivefold increase.'
There could be many different reasons for author inflation; more interdisciplinary research, technological advances, the closer monitoring of performance indicators in scientific institutions that has led to the inclusion of students, lab assistants, junior staff and technical staff as authors on papers.
Robert comments: 'Using crude measures of author numbers to measure taxonomic capacity at a time of author inflation across all of science has the potential to be highly misleading for future planners and policy makers in this area of science.
'Our study found that in fact a very large number of new species are discovered and described by a very small number of prolific botanists, and more than 50% of all authors are only ever associated with naming a single species.
'It shows that there remain huge uncertainties surrounding our capacity to describe the world’s species before they go extinct.'(Full story)