New research using ancient DNA has revealed that plague has been endemic in human populations for more than twice as long as previously thought, and that the ancestral plague would have been predominantly spread by human-to-human contact – until genetic mutations allowedYersinia pestis (Y. pestis), the bacteria that causes plague, to survive in the gut of fleas.

These mutations, which may have occurred near the turn of the 1st millennium BC, gave rise to the bubonic form of plague that spreads at terrifying speed through flea – and consequently rat – carriers. The bubonic plague caused the pandemics that decimated global populations, including the Black Death, which wiped out half the population of Europe in the 14th century.

Before its flea-borne evolution, however, researchers say that plague was in fact endemic in the human populations of Eurasia at least 3,000 years before the first plague pandemic in historical records (the Plague of Justinian in 541 AD).

They say the new evidence that Y. pestis bacterial infection in humans actually emerged around the beginning of the Bronze Age suggests that plague may have been responsible for major population declines believed to have occurred in the late 4th and early 3rd millennium BC.

The work was conducted by an international team including researchers from the universities of Copenhagen, Denmark, and Cambridge, UK, and the findings are published today in the journal Cell.

“We found that the Y. pestis lineage originated and was widespread much earlier than previously thought, and we narrowed the time window as to when and how it developed,” said senior author Professor Eske Willerslev, who recently joined Cambridge University’s Department of Zoology from the University of Copenhagen.

“The underlying mechanisms that facilitated the evolution of Y. pestis are present even today. Learning from the past may help us understand how future pathogens may arise and evolve,” he said.

Researchers analysed ancient genomes extracted from the teeth of 101 adults dating from the Bronze Age and found across the Eurasian landmass.

They found Y. pestis bacteria in the DNA of seven of the adults, the oldest of whom died 5,783 years ago – the earliest evidence of plague. Previously, direct molecular evidence forY. pestis had not been obtained from skeletal material older than 1,500 years.

However, six of the seven plague samples were missing two key genetic components found in most modern strains of plague: a “virulence gene” called ymt, and a mutation in an “activator gene” called pla.

The ymt gene protects the bacteria from being destroyed by the toxins in flea guts, so that it multiplies, choking the flea’s digestive tract. This causes the starving flea to frantically bite anything it can, and, in doing so, spread the plague.

The mutation in the pla gene allows Y. pestis bacteria to spread across different tissues, turning the localised lung infection of pneumonic plague into one of the blood and lymph nodes.

Researchers concluded these early strains of plague could not have been carried by fleas without ymt. Nor could they cause bubonic plague – which affects the lymphatic immune system, and inflicts the infamous swollen buboes of the Black Death – without the plamutation.

Consequently, the plague that stalked populations for much of the Bronze Age must have been pneumonic, which directly affects the respiratory system and causes desperate, hacking coughing fits just before death. Breathing around infected people leads to inhalation of the bacteria, the crux of its human-to-human transmission.

Study co-author Dr Marta Mirazón-Lahr, from Cambridge’s Leverhulme Centre for Human Evolutionary Studies (LCHES), points out that a study earlier this year from Willerslev’s Copenhagen group showed the Bronze Age to be a highly active migratory period, which could have led to the spread of pneumonic plague.

“The Bronze Age was a period of major metal weapon production, and it is thought increased warfare, which is compatible with emerging evidence of large population movements at the time. If pneumonic plague was carried as part of these migrations, it would have had devastating effects on small groups they encountered,” she said.

“Well-documented cases have shown the pneumonic plague’s chain of infection can go from a single hunter or herder to ravaging an entire community in two to three days.”

The most recent of the seven ancient genomes to reveal Y. pestis in the new study has both of the key genetic mutations, indicating an approximate timeline for the evolution that spawned flea-borne bubonic plague.

“Among our samples, the mutated plague strain is first observed in Armenia in 951 BC, yet is absent in the next most recent sample from 1686 BC – suggesting bubonic strains evolve and become fixed in the late 2nd and very early 1st millennium BC,” said Mirazón-Lahr.

“However, the 1686 BC sample is from the Altai mountains near Mongolia. Given the distance between Armenia and Altai, it’s also possible that the Armenian strain of bubonic plague has a longer history in the Middle East, and that historical movements during the 1st millennium BC exported it elsewhere.”

The Books of Samuel in the Bible describe an outbreak of plague among the Philistines in 1320 BC, complete with swellings in the groin, which the World Health Organization has argued fits the description of bubonic plague. Mirazón-Lahr suggests this may support the idea of a Middle Eastern origin for the plague’s highly lethal genetic evolution.

Co-author Professor Robert Foley, also from Cambridge’s LCHES, suggests that the lethality of bubonic plague may have required the right population demography before it could thrive.

“Every pathogen has a balance to maintain. If it kills a host before it can spread, it too reaches a ‘dead end’. Highly lethal diseases require certain demographic intensity to sustain them.

“The endemic nature of pneumonic plague was perhaps more adapted for an earlier Bronze Age population. Then, as Eurasian societies grew in complexity and trading routes continued to open up, maybe the conditions started to favour the more lethal form of plague,” Foley said.

“The Bronze Age is the edge of history, and ancient DNA is making what happened at this critical time more visible,” he said.

Willerslev added: “These results show that the ancient DNA has the potential not only to map our history and prehistory, but also discover how disease may have shaped it.”

Inset image: Map showing where the remains of the Bronze Age plague victims were found.

The researchers studied tiny protein-producing factories, called ribosomes, isolated from cells. They capitalised on improvements made at the LMB to a high-powered imaging technique known as single particle cryo-electron microscopy.

The microscopes, capable of achieving detail near to the atomic level, enabled the team to link the molecular origins of a rare inherited leukaemia predisposition disorder, ‘Shwachman-Diamond Syndrome’ and a more common form of acute leukaemia to a common pathway involved in the construction of ribosomes.

Cryo-EM map showing the large ribosomal subunit (cyan), eIF6 (yellow) and the SBDS protein (magenta) that is deficient in the inherited leukaemia predisposition disorder Shwachman-Diamond syndrome. Credit: Alan Warren, University of Cambridge

The research, funded by the blood cancer charity Bloodwise and the Medical Research Council (MRC), is published online in the journal Nature Structural and Molecular Biology.

Ribosomes are the molecular machinery in cells that produce proteins by ‘translating’ the instructions contained in DNA via an intermediary messenger molecule. Errors in this process are known to play a part in the development of some bone marrow disorders and leukaemias. Until now scientists have been unable to study ribosomes at a high enough resolution to understand exactly what goes wrong.

Ribosomes are constructed in a series of discrete steps, like an assembly line. One of the final assembly steps involves the release of a key building block that allows the ribosome to become fully functional. The research team showed that a corrupted mechanism underlying this fundamental late step prevents proper assembly of the ribosome.

This provides an explanation for how cellular processes go awry in both Shwachman-Diamond syndrome and one in 10 cases of T-cell acute lymphoblastic leukaemia. This form of leukaemia, which affects around 60 children and young teenagers a year in the UK, is harder to treat than the more common B-cell form.

The findings from the Cambridge scientists, who worked in collaboration with scientists at the University of Rennes in France, open up the possibility that a single drug designed to target this molecular fault could be developed to treat both diseases.

Professor Alan Warren, from the Cambridge Institute of Medical Research at the University of Cambridge, said: “We are starting to find that many forms of blood cancer can be traced back to defects in the basic housekeeping processes in our cells’ maturation. Pioneering improvements to electron microscopes pave the way for the creation of a detailed map of the how these diseases develop, in a way that was never possible before.”

Single particle cryo-electron microscopy preserves the ribosomes at sub-zero temperatures to allow the collection and amalgamation of multiple images of maturing ribosomes in different orientations to ultimately provide more detail.

The technique has been refined in the MRC Laboratory of Molecular Biology by the development of new ‘direct electron detectors’ to better sense the electrons, yielding images of unprecedented quality. Methods to correct for beam-induced sample movements and new classification methods that can separate out several different structures within a single sample have also been developed.

Dr Matt Kaiser, Head of Research at Bloodwise, said: “New insights into the biology of blood cancers and disorders that originate in the bone marrow have only been made possible by the latest advances in technology. While survival rates for childhood leukaemia have improved dramatically over the years, this particular form of leukaemia is harder to treat and still relies on toxic chemotherapy. These findings will offer hope that new, more targeted, treatments can be developed.”

The research received additional funding from a Federation of European Biochemical Societies (FEBS) Long term Fellowship, the SDS patient charity Ted’s Gang and the Cambridge NIHR Biomedical Research Centre.

Adapted from a press release by Bloodwise

Reference
Weis, F et al. Mechanism of eIF6 release from the nascent 60S ribosomal subunit. Nature Structural and Molecular Biology; 19 Oct 2015

A low-cost, high-speed method for printing graphene inks using a conventional roll-to-roll printing process, like that used to print newspapers and crisp packets, could open up a wide range of practical applications, including inexpensive printed electronics, intelligent packaging and disposable sensors.

Developed by researchers at the University of Cambridge in collaboration with Cambridge-based technology company Novalia, the method allows graphene and other electrically conducting materials to be added to conventional water-based inks and printed using typical commercial equipment, the first time that graphene has been used for printing on a large-scale commercial printing press at high speed.

Graphene is a two-dimensional sheet of carbon atoms, just one atom thick. Its flexibility, optical transparency and electrical conductivity make it suitable for a wide range of applications, including printed electronics. Although numerous laboratory prototypes have been demonstrated around the world, widespread commercial use of graphene is yet to be realised.

“We are pleased to be the first to bring graphene inks close to real-world manufacturing. There are lots of companies that have produced graphene inks, but none of them has done it on a scale close to this,” said Dr Tawfique Hasan of the Cambridge Graphene Centre (CGC), who developed the method. “Being able to produce conductive inks that could effortlessly be used for printing at a commercial scale at a very high speed will open up all kinds of different applications for graphene and other similar materials.”

“This method will allow us to put electronic systems into entirely unexpected shapes,” said Chris Jones of Novalia. “It’s an incredibly flexible enabling technology.”

Hasan’s method, developed at the University’s Nanoscience Centre, works by suspending tiny particles of graphene in a ‘carrier’ solvent mixture, which is added to conductive water-based ink formulations. The ratio of the ingredients can be adjusted to control the liquid’s properties, allowing the carrier solvent to be easily mixed into a conventional conductive water-based ink to significantly reduce the resistance. The same method works for materials other than graphene, including metallic, semiconducting and insulating nanoparticles.

Currently, printed conductive patterns use a combination of poorly conducting carbon with other materials, most commonly silver, which is expensive. Silver-based inks cost £1000 or more per kilogram, whereas this new graphene ink formulation would be 25 times cheaper. Additionally, silver is not recyclable, while graphene and other carbon materials can easily be recycled. The new method uses cheap, non-toxic and environmentally friendly solvents that can be dried quickly at room temperature, reducing energy costs for ink curing. Once dry, the ‘electric ink’ is also waterproof and adheres to its substrate extremely well.

The graphene-based inks have been printed at a rate of more than 100 metres per minute, which is in line with commercial production rates for graphics printing, and far faster than earlier prototypes. Two years ago, Hasan and his colleagues produced a prototype of a transparent and flexible piano using graphene-based inks, which took between six and eight hours to make. Through the use of this new ink, more versatile devices on paper or plastic can be made at a rate of 300 per minute, at a very low cost. Novalia has also produced a printed DJ deck and an interactive poster, which functions as a drum kit using the same method.

Hasan and PhD students Guohua Hu, Richard Howe and Zongyin Yang of the Hybrid Nanomaterials Engineering group at CGC, in collaboration with Novalia, tested the method on a typical commercial printing press, which required no modifications in order to print with the graphene ink. In addition to the new applications the method will open up for graphene, it could also initiate entirely new business opportunities for commercial graphics printers, who could diversify into the electronics sector.

“The UK, and the Cambridge area in particular, has always been strong in the printing sector, but mostly for graphics printing and packaging,” said Hasan, a Royal Academy of Engineering Research Fellow and a University Lecturer in the Engineering Department. “We hope to use this strong local expertise to expand our functional ink platform. In addition to cheaper printable electronics, this technology opens up potential application areas such as smart packaging and disposable sensors, which to date have largely been inaccessible due to cost.”

In the short to medium term, the researchers hope to use their method to make printed, disposable biosensors, energy harvesters and RFID tags.

The research was supported by grants from the Engineering and Physical Sciences Research Council’s Impact Acceleration Account and a Royal Academy of Engineering Research Fellowship. The technology is being commercialised by Cambridge Enterprise, the University’s commercialisation arm.

The accuracy and reliability of expert advice is often compromised by “cognitive frailties”, and needs to be interrogated with the same tenacity as research data to avoid weak and ill-informed policy, warn two leading risk analysis and conservation researchers in thejournal Nature today.

While many governments aspire to evidence-based policy, the researchers say the evidence on experts themselves actually shows that they are highly susceptible to “subjective influences” – from individual values and mood, to whether they stand to gain or lose from a decision – and, while highly credible, experts often vastly overestimate their objectivity and the reliability of peers.

The researchers caution that conventional approaches of informing policy by seeking advice from either well-regarded individuals or assembling expert panels needs to be balanced with methods that alleviate the effects of psychological and motivational bias.

They offer a straightforward framework for improving expert advice, and say that experts should provide and assess evidence on which decisions are made – but not advise decision makers directly, which can skew impartiality.

“We are not advocating replacing evidence with expert judgements, rather we suggest integrating and improving them,” write professors William Sutherland and Mark Burgman from the universities of Cambridge and Melbourne respectively.

“Policy makers use expert evidence as though it were data. So they should treat expert estimates with the same critical rigour that must be applied to data,” they write.

“Experts must be tested, their biases minimised, their accuracy improved, and their estimates validated with independent evidence. Put simply, experts should be held accountable for their opinions.”

Sutherland and Burgman point out that highly regarded experts are routinely shown to be no better than novices at making judgements.

However, several processes have been shown to improve performances across the spectrum, they say, such as ‘horizon scanning’ – identifying all possible changes and threats – and ‘solution scanning’ – listing all possible options, using both experts and evidence, to reduce the risk of overlooking valuable alternatives.

To get better answers from experts, they need better, more structured questions, say the authors. “A seemingly straightforward question, ‘How many diseased animals are there in the area?’ for example, could be interpreted very differently by different people. Does it include those that are infectious and those that have recovered? What about those yet to be identified?” said Sutherland, from Cambridge’s Department of Zoology.

“Structured question formats that extract upper and lower boundaries, degrees of confidence and force consideration of alternative theories are important for shoring against slides into group-think, or individuals getting ascribed greater credibility based on appearance or background,” he said.

When seeking expert advice, all parties must be clear about what they expect of each other, says Burgman, Director of the Centre of Excellence for Biosecurity Risk Analysis. “Are policy makers expecting estimates of facts, predictions of the outcome of events, or advice on the best course of action?”

“Properly managed, experts can help with estimates and predictions, but providing advice assumes the expert shares the same values and objectives as the decision makers. Experts need to stick to helping provide and assess evidence on which such decisions are made,” he said.

Sutherland and Burgman have created a framework of eight key ways to improve the advice of experts. These include using groups – not individuals – with diverse, carefully selected members well within their expertise areas.

They also caution against being bullied or “starstruck” by the over-assertive or heavyweight. “People who are less self-assured will seek information from a more diverse range of sources, and age, number of qualifications and years of experience do not explain an expert’s ability to predict future events – a finding that applies in studies from geopolitics to ecology,” said Sutherland.

Added Burgman: “Some experts are much better than others at estimation and prediction. However, the only way to tell a good expert from a poor one is to test them. Qualifications and experience don’t help to tell them apart.”

“The cost of ignoring these techniques – of using experts inexpertly – is less accurate information and so more frequent, and more serious, policy failures,” write the researchers.

A new study of the relationship between ocean currents and climate change has found that they are tightly linked, and that changes in the polar regions can affect the ocean and climate on the opposite side of the world within one to two hundred years, far quicker than previously thought.

The study, by an international team of scientists led by the University of Cambridge, examined how changes in ocean currents in the Atlantic Ocean were related to climate conditions in the northern hemisphere during the last ice age, by examining data from ice cores and fossilised plankton shells. It found that variations in ocean currents and abrupt climate events in the North Atlantic region were tightly linked in the past, and that changes in the polar regions affected the ocean circulation and climate on the opposite side of the world.

The researchers determined that as large amounts of fresh water were emptied into the North Atlantic as icebergs broke off the North American and Eurasian ice sheets, the deep and shallow currents in the North Atlantic rapidly slowed down, which led to the formation of sea ice around Greenland and the subsequent cooling of the Northern Hemisphere. It also strongly affected conditions in the South Atlantic within a matter of one to two hundred years. The results, published in the journal Nature Geoscience, show how climate events in the Northern Hemisphere were tightly coupled with changes in the strength of deep ocean currents in the Atlantic Ocean, and how that may have affected conditions across the globe.

During the last ice age, which took place from 70,000 to 19,000 years ago, the climate in the Northern Hemisphere toggled back and forth between warm and cold states roughly every 1000 to 6000 years. These events, known as Dansgaard-Oeschger events, were first identified in data from Greenland ice cores in the early 1990s, and had far-reaching impacts on the global climate.

The ocean, which covers 70% of the planet, is a huge reservoir of carbon dioxide and heat. It stores about 60 times more carbon than the atmosphere, and can release or take up carbon on both short and long timescales. As changes happen in the polar regions, they are carried around the world by ocean currents, both at the surface and in the deep ocean. These currents are driven by winds, ocean temperature and salinity differences, and are efficient at distributing heat and carbon around the globe. Ocean currents therefore have a strong influence on whether regions of the world are warm (such as Europe) or whether they are not (such as Antarctica) as they modulate the effects of solar radiation. They also influence whether CO2 is stored in the ocean or the atmosphere, which is very important for global climate variability.

“Other studies have shown that the overturning circulation in the Atlantic has faced a slowdown during the last few decades,” said Dr Julia Gottschalk of Cambridge Department of Earth Sciences, the paper’s lead author. “The scientific community is only beginning to understand what it would mean for global climate should this trend continue, as predicted by some climate models.”

Analysing new data from marine sediment cores taken from the deep South Atlantic, between the southern tip of South America and the southern tip of Africa, the researchers discovered that during the last ice age, deep ocean currents in the South Atlantic varied essentially in unison with Greenland ice-core temperatures. “This implies that a very rapid transmission process must have operated, that linked rapid climate change around Greenland with the otherwise sluggish deep Atlantic Ocean circulation,” said Gottschalk, who is a Gates Cambridge Scholar. Best estimates of the delay between these two records suggest that the transmission happened within about 100 to 200 years.

Digging through metres of ocean mud from depths of 3,800 metres, the team studied the dissolution of fossil plankton shells that was closely linked to the chemical signature of different water masses. Water masses originating in the North Atlantic are less corrosive than water masses from the South Atlantic.

“Periods of very intense North Atlantic circulation and higher Northern Hemisphere temperatures increased the preservation of microfossils in the sediment cores, whereas those with slower circulation, when the study site was primarily influenced from the south, were linked with decreased carbonate ion concentrations at our core site which led to partial dissolution,” said co-author Dr Luke Skinner, also from Cambridge’s Department of Earth Sciences.

To better understand the physical mechanisms of rapid ocean adjustment, the data was compared with a climate model simulation which covers the same period. “The data of the model simulation was so close to the deep ocean sediment data, that we knew immediately, we were on the right track,” said co-author Dr Laurie Menviel from the University of New South Wales, Australia, who conducted the model simulation.

The timescales of these large-scale adjustments found in the palaeoceanographic data agree extremely well with those predicted by the model. “Waves between layers of different density in the deep ocean are responsible for quickly transmitting signals from North to South. This is a paradigm shift in our understanding of how the ocean works,” said Axel Timmermann, Professor of Oceanography at the University of Hawaii.

Although conditions at the end of the last ice age were very different to those of today, the findings could shed light on how changing conditions in the polar regions may affect ocean currents. However, much more research is needed in this area. The study’s findings could help test and improve climate models that are run for both past and future conditions.

The sediment cores were recovered by Dr Claire Waelbroeck and colleagues aboard the French research vessel Marion Dufresne.

The research was supported by the Gates Cambridge Trust, the Natural Environmental Research Council of the UK, the Royal Society, the European Research Council, the Australian Research Council and the National Science Foundation of the United States of America.

Reference:
Gottschalk, J et. al. Abrupt changes in the southern extent of North Atlantic Deep Water during Dansgaard-Oeschger events. Nature Geoscience (2015). DOI: 10.1038/ngeo2558

Take a look at the black and white image. It probably looks like a meaningless pattern of black and white blotches. But now take a look at the image at the bottom of this article and then return to the black and white picture: it’s likely that you can now make sense of the black and white image. It is this ability that scientists at Cardiff University and the University of Cambridge believe could help explain why some people are prone to hallucinations.

A bewildering and often very frightening experience in some mental illnesses is psychosis – a loss of contact with external reality. This often results in a difficulty in making sense of the world, which can appear threatening, intrusive and confusing. Psychosis is sometimes accompanied by drastic changes in perception, to the extent that people may see, feel, smell and taste things that are not actually there – so-called hallucinations. These hallucinations may be accompanied by beliefs that others find irrational and impossible to comprehend.

In research published today in the journal Proceedings of National Academy of Sciences (PNAS), a team of researchers based at Cardiff University and the University of Cambridge explore the idea that hallucinations arise due to an enhancement of our normal tendency to interpret the world around us by making use of prior knowledge and predictions.

In order to make sense of and interact with our physical and social environment, we need appropriate information about the world around us, for example the size or location of a nearby object. However, we have no direct access to this information and are forced to interpret potentially ambiguous and incomplete information from our senses. This challenge is overcome in the brain – for example in our visual system – by combining ambiguous sensory information with our prior knowledge of the environment to generate a robust and unambiguous representation of the world around us. For example, when we enter our living room, we may have little difficulty discerning a fast-moving black shape as the cat, even though the visual input was little more than a blur that rapidly disappeared behind the sofa: the actual sensory input was minimal and our prior knowledge did all the creative work.

“Vision is a constructive process – in other words, our brain makes up the world that we ‘see’,” explains first author Dr Christoph Teufel from the School of Psychology at Cardiff University. “It fills in the blanks, ignoring the things that don’t quite fit, and presents to us an image of the world that has been edited and made to fit with what we expect.”

“Having a predictive brain is very useful – it makes us efficient and adept at creating a coherent picture of an ambiguous and complex world,” adds senior author Professor Paul Fletcher from the Department of Psychiatry at the University of Cambridge. “But it also means that we are not very far away from perceiving things that aren’t actually there, which is the definition of a hallucination.

“In fact, in recent years we’ve come to realise that such altered perceptual experiences are by no means restricted to people with mental illness. They are relatively common, in a milder form, across the entire population. Many of us will have heard or seen things that aren’t there.”

In order to address the question of whether such predictive processes contribute to the emergence of psychosis, the researchers worked with 18 individuals who had been referred to a mental health service run by the NHS Cambridgeshire and Peterborough Foundation Trust, and led by Dr Jesus Perez, one of the co-authors on the study, and who suffered from very early signs of psychosis. They examined how these individuals, as well as a group of 16 healthy volunteers, were able to use predictions in order to make sense of ambiguous, incomplete black and white images, similar to the one shown above.

The volunteers were asked to look at a series of these black and white images, some of which contained a person, and then to say for a given image whether or not it contained a person. Because of the ambiguous nature of the images, the task was very difficult at first. Participants were then shown a series of full colour original images, including those from which the black and white images had been derived: this information could be used to improve the brain’s ability to make sense of the ambiguous image. The researchers reasoned that, since hallucinations may come from a greater tendency to superimpose one’s predictions on the world, people who were prone to hallucinations would be better at using this information because, in this task, such a strategy would be an advantage.

The researchers found a larger performance improvement in people with very early signs of psychosis in comparison to the healthy control group. This suggested that people from the clinical group were indeed relying more strongly on the information that they had been given to make sense of the ambiguous pictures.

When the researchers presented the same task to a larger group of 40 healthy people, they found a continuum in task performance that correlated with the participants’ scores on tests of psychosis-proneness. In other words, the shift in information processing that favours prior knowledge over sensory input during perception can be detected even before the onset of early psychotic symptoms.

“These findings are important because they tell us that the emergence of key symptoms of mental illness can be understood in terms of an altered balance in normal brain functions,” says Naresh Subramaniam from the Department of Psychiatry at the University of Cambridge. “Importantly, they also suggest that these symptoms and experiences do not reflect a ‘broken’ brain but rather one that is striving – in a very natural way – to make sense of incoming data that are ambiguous.”

The study was carried out in collaboration with Dr Veronika Dobler and Professor Ian Goodyer from the Department of Child and Adolescent Psychiatry at the University of Cambridge. The research was funded by the Wellcome Trust and the Bernard Wolfe Health Neuroscience Fund. It was carried out within the Cambridge and Peterborough NHS Foundation Trust. Additional support for the Behavioural and Clinical Neuroscience Institute at the University of Cambridge came from the Wellcome Trust and the Medical Research Council.

Reference
Teufel, C et al. Shift towards prior knowledge confers a perceptual advantage in early psychosis and psychosis-prone healthy individuals. PNAS; 12 Oct 2015

The first ancient human genome from Africa to be sequenced has revealed that a wave of migration back into Africa from Western Eurasia around 3,000 years ago was up to twice as significant as previously thought, and affected the genetic make-up of populations across the entire African continent.

The genome was taken from the skull of a man buried face-down 4,500 years ago in a cave called Mota in the highlands of Ethiopia – a cave cool and dry enough to preserve his DNA for thousands of years. Previously, ancient genome analysis has been limited to samples from northern and arctic regions.

The latest study is the first time an ancient human genome has been recovered and sequenced from Africa, the source of all human genetic diversity. The findings are published today in the journal Science.

The ancient genome predates a mysterious migratory event which occurred roughly 3,000 years ago, known as the ‘Eurasian backflow’, when people from regions of Western Eurasia such as the Near East and Anatolia suddenly flooded back into the Horn of Africa.

The genome enabled researchers to run a millennia-spanning genetic comparison and determine that these Western Eurasians were closely related to the Early Neolithic farmers who had brought agriculture to Europe 4,000 years earlier.

By comparing the ancient genome to DNA from modern Africans, the team have been able to show that not only do East African populations today have as much as 25% Eurasian ancestry from this event, but that African populations in all corners of the continent – from the far West to the South – have at least 5% of their genome traceable to the Eurasian migration.

Researchers describe the findings as evidence that the ‘backflow’ event was of far greater size and influence than previously thought. The massive wave of migration was perhaps equivalent to over a quarter of the then population of the Horn of Africa, which hit the area and then dispersed genetically across the whole continent.

“Roughly speaking, the wave of West Eurasian migration back into the Horn of Africa could have been as much as 30% of the population that already lived there – and that, to me, is mind-blowing. The question is: what got them moving all of a sudden?” said Dr Andrea Manica, senior author of the study from the University of Cambridge’s Department of Zoology.

Previous work on ancient genetics in Africa had involved trying to work back through the genomes of current populations, attempting to eliminate modern influences. “With an ancient genome, we have a direct window into the distant past. One genome from one individual can provide a picture of an entire population,” said Manica.

The cause of the West Eurasian migration back into Africa is currently a mystery, with no obvious climatic reasons. Archaeological evidence does, however, show the migration coincided with the arrival of Near Eastern crops into East Africa such as wheat and barley, suggesting the migrants helped develop new forms of agriculture in the region.

The researchers say it’s clear that the Eurasian migrants were direct descendants of, or a very close population to, the Neolithic farmers that had had brought agriculture from the Near East into West Eurasia around 7,000 years ago, and then migrated into the Horn of Africa some 4,000 years later. “It’s quite remarkable that genetically-speaking this is the same population that left the Near East several millennia previously,” said Eppie Jones, a geneticist at Trinity College Dublin who led the laboratory work to sequence the genome.

While the genetic make-up of the Near East has changed completely over the last few thousand years, the closest modern equivalents to these Neolithic migrants are Sardinians, probably because Sardinia is an isolated island, says Jones. “The famers found their way to Sardinia and created a bit of a time capsule. Sardinian ancestry is closest to the ancient Near East.”

View looking out from the Mota cave in the Ethiopian highlands

“Genomes from this migration seeped right across the continent, way beyond East Africa, from the Yoruba on the western coast to the Mbuti in the heart of the Congo – who show as much as 7% and 6% of their genomes respectively to be West Eurasian,” said Marcos Gallego Llorente, first author of the study, also from Cambridge’s Zoology Department.

“Africa is a total melting pot. We know that the last 3,000 years saw a complete scrambling of population genetics in Africa. So being able to get a snapshot from before these migration events occurred is a big step,” Gallego Llorente said.

The ancient Mota genome allows researchers to jump to before another major African migration: the Bantu expansion, when speakers of an early Bantu language flowed out of West Africa and into central and southern areas around 3,000 years ago. Manica says the Bantu expansion may well have helped carry the Eurasian genomes to the continent’s furthest corners.

The researchers also identified genetic adaptations for living at altitude, and a lack of genes for lactose tolerance – all genetic traits shared by the current populations of the Ethiopian highlands. In fact, the researchers found that modern inhabitants of the area highlands are direct descendants of the Mota man.

Finding high-quality ancient DNA involves a lot of luck, says Dr Ron Pinhasi, co-senior author from University College Dublin. “It’s hard to get your hands on remains that have been suitably preserved. The denser the bone, the more likely you are to find DNA that’s been protected from degradation, so teeth are often used, but we found an even better bone – the petrous.” The petrous bone is a thick part of the temporal bone at the base of the skull, just behind the ear.

“The sequencing of ancient genomes is still so new, and it’s changing the way we reconstruct human origins,” added Manica. “These new techniques will keep evolving, enabling us to gain an ever-clearer understanding of who our earliest ancestors were.”

The study was conducted by an international team of researchers, with permission from the Ethiopia’s Ministry of Culture and Authority for Research and Conservation of Cultural Heritage.

The study, published today in the journal Nature Communications, may have significant implications for the development of future medicines for disorders that affect myelin sheath, the insulation that protects and insulates our nerve cells.

For our brain and central nervous system to work, electrical signals must travel quickly along nerve fibres. This is achieved by insulating the nerve fibres with a fatty substance called myelin. In diseases such as MS, the myelin sheath around nerve fibres is lost or damaged, causing physical and mental disability.

Stem cells – the body’s master cells, which can develop into almost any type of cell – can act as ‘first aid kits’, repairing damage to the body. In our nervous system, these stem cells are capable of producing new myelin, which, in the case of MS, for example, can help recover lost function. However, myelin repair often fails, leading to sustained disability. To understand why repair fails in disease, and to design novel ways of promoting myelin repair, researchers at the Wellcome Trust-Medical Research Council Stem Cell Institute at the University of Cambridge studied how this repair process works.

When nerve fibres lose myelin, they stay active but conduct signals at much lower speed than healthy fibres. Using electrical recording techniques, a team of researchers led by Dr Thora Karadottir discovered that the damaged nerve fibres then form connections with stem cells. These connections are the same as those that connect synapses between different nerve fibres. These new synaptic connections enable the damaged fibres to communicate directly with the stem cells by releasing the glutamate, a chemical that the stem cells can sense via receptors. This communication is critical for directing the stem cells to produce new myelin – when the researchers inhibited either the nerve fibres’ activity, their ability to communicate, or the stem cells’ ability to sense the communication, the repair process fails.

“This is the first time that we’ve been able to show that damaged nerve fibres communicate with stem cells using synaptic connections – the same connections they use to ‘talk to’ other nerve cells,” says Dr Karadottir. “Armed with this new knowledge, we can start looking into ways to enhance this communication to promote myelin repair in disease.”

Dr Helene Gautier from the Department of Physiology, Development and Neuroscience, adds: “So far, the majority of the available treatments are only slowing down damage. Our research opens the possibility to enhance repair and potentially treat the most devastating forms of MS and demyelinated diseases.”

Reference
Gautier, HOB et al. Neuronal activity regulates remyelination via glutamate signalling to oligodendrocyte progenitors. Nature Communications; 6 Oct 2015

An international team of researchers, led by the University of Cambridge, has estimated the amount of hydrocarbons – the primary ingredient in crude oil – that are produced by a massive population of photosynthetic marine microbes, called cyanobacteria. These organisms in turn support another population of bacteria that ‘feed’ on these compounds.

In the study, conducted in collaboration with researchers from the University of Warwick and MIT, and published today (5 October) in the journal Proceedings of the National Academy of Sciences of the USA, the scientists measured the amount of hydrocarbons in a range of laboratory-grown cyanobacteria and used the data to estimate the amount produced in the oceans.

Although each individual cell contains minuscule quantities of hydrocarbons, the researchers estimated that the amount produced by two of the most abundant cyanobacteria in the world – Prochlorococcus and Synechococcus – is more than two million tonnes in the ocean at any one time. This indicates that these two groups alone produce between 300 and 800 million tonnes of hydrocarbons per year, yet the concentration at any time in unpolluted areas of the oceans is tiny, thanks to other bacteria that break down the hydrocarbons as they are produced.

“Hydrocarbons are ubiquitous in the oceans, even in areas with minimal crude oil pollution, but what hadn’t been recognised until now is the likely quantity produced continually by living oceanic organisms,” said Professor Christopher Howe from Cambridge’s Department of Biochemistry, the paper’s senior author. “Based on our laboratory studies, we believe that at least two groups of cyanobacteria are responsible for the production of massive amounts of hydrocarbons, and this supports other bacteria that break down the hydrocarbons as they are produced.”

The scientists argue that the cyanobacteria are key players in an important biogeochemical cycle, which they refer to as the short-term hydrocarbon cycle. The study suggests that the amount of hydrocarbons produced by cyanobacteria dwarfs the amount of crude oil released into the seas by natural seepage or accidental oil spills.

However, the hydrocarbons produced by cyanobacteria are continually broken down by other bacteria, keeping the overall concentrations low. When an event such as an oil spill occurs, hydrocarbon-degrading bacteria are known to spring into action, with their numbers rapidly expanding, fuelled by the sudden local increase in their primary source of energy.

The researchers caution that their results do not in any way diminish the enormous harm caused by oil spills. Although some microorganisms are known to break down hydrocarbons in oil spills, they cannot repair the damage done to marine life, seabirds and coastal ecosystems.

“Oil spills cause widespread damage, but some parts of the marine environment recover faster than others,” said Dr David Lea-Smith, a postdoctoral researcher in the Department of Biochemistry, and the paper’s lead author. “This cycle is like an insurance policy – the hydrocarbon-producing and hydrocarbon-degrading bacteria exist in equilibrium with each other, and the latter multiply if and when an oil spill happens. However, these bacteria cannot reverse the damage to ecosystems which oil spills cause.”

The researchers stress the need to test if their findings are supported by direct measurements on cyanobacteria growing in the oceans. They are also interested in the possibility of harnessing the hydrocarbon production potential of cyanobacteria industrially as a possible source of fuel in the future, although such work is at a very early stage.

Reference:
Lea-Smith, D. et. al. “Contribution of cyanobacterial alkane production to the ocean hydrocarbon cycle.” PNAS (2015). DOI: 10.1073/pnas.1507274112

Trainee doctors think they are being asked to prolong some patients’ lives unnecessarily and describe such cases as being tantamount to torture and abuse, according to a new study.

The research, led by Elizabeth Dzeng, a Gates Cambridge Scholar at the University of Cambridge, is the first to focus on US doctors’ moral distress surrounding resuscitation and treatments that they believe may be futile at the end of life and has implications for the UK as more power is handed from doctors to patients’ representatives around end of life issues.

The qualitative study, titled “Moral Distress Amongst American Physician Trainees Regarding Futile Treatments at the End of Life: A Qualitative Inquiry”, is published in the Journal of General Internal Medicine.

Elizabeth conducted in-depth interviews with 22 physician trainees in internal medicine at three accredited medical centres in the US and asked how they reacted and responded to ethical challenges arising in the context of perceived futile treatments at the end of life and how they felt about its ethical implications.

It found that doctors who are required to perform procedures such as resuscitation which they feel are futile or harmful have significant moral qualms that they are prolonging suffering as opposed to providing care. Some cope with these by developing detached and dehumanising attitudes towards patients.

One said of a patient: “It felt horrible, like I was torturing him. He was telling us we were torturing him. I did not think we were doing the right things.”

Another said: “I agree with giving the patient’s choice, but oftentimes it’s the family member. If the patient says, “Torture me, I want everything done.” Fine. The family member is doing it for other reasons. Like guilt; they can’t let go.”

Ways of coping ranged from formal and informal conversations with colleagues and superiors about the emotional and ethical challenges of providing care at the end of life to a tendency among some to dehumanise the patient.

One trainee said: “We’re abusing a body and I get that, but as long as I remember I’m only abusing a body and not a person, it’s okay. Frequently when it’s an inappropriate code, that’s what’s happening.”

Trainees also said that the hierarchical nature of their relationship with other doctors meant they felt powerless to have any influence on decisions.

Dzeng [2011] is completing a PhD on medical sociology and ethics and is also a fellow in General Internal Medicine at the Johns Hopkins School of Medicine. She said: “Our study sheds light on a significant cause of moral distress amongst physician trainees when they feel obligated to provide treatments at the end of life that they believe to be futile or harmful. Their words – ‘torture’, ‘gruesome’, ‘abuse’, ‘mutilate’ and ‘cruel’ evoke images more fitting of penal regimes than hospitals. The moral toll exacted upon these physicians is evident in descriptions such as feeling ‘violated’ and ‘traumatised’. Previous research shows that moral distress can have significant negative effects on job satisfaction, psychological and physical well-being and self-image, resulting in burnout and thoughts of quitting.”

The paper is part of a larger study investigating the influence of institutional cultures and policies on physicians’ and trainees’ views on resuscitation orders. A previous paper found that in hospitals with cultures and policies which prioritised patient autonomy over the patients’ best interest, physicians tended to give patients a menu of choices without guidance or recommendations over whether resuscitation would be beneficial or merely prolong suffering. It explored the effect of moves towards greater patient autonomy over end of life decisions. Although this was an understandable reaction to the paternalistic approach often adopted by doctors in the past, the paper voiced fears that the pendulum may have swung too far, to the detriment of patients themselves.

Fully exploiting the Government’s education data could help to bridge the skills gap that is holding back UK businesses, Cambridge expert Professor Anna Vignoles has said at aRustat Conference session on the application of Big Data, held at Jesus College.

The UK’s skills gap has been highlighted by both the Confederation of British Industry(CBI) and the Chartered Institute of Management Accountants (CIMA) this year. The CBI reported that over half of employers (55%) are not confident there will be enough people available in the future with the necessary skills to fill their high-skilled jobs¹.

In the last ten years, the Government has allowed researchers to access some of its educational data under secure conditions. Academics including Vignoles have recently mapped the journeys taken by students from the age of four right through to employment.

During a session on the application of Big Data and data driven business models, Vignoles argued that researchers could now use earnings data to determine which skills are in greater demand in the labour market, and feed this back into policy to ensure that the education system teaches the skills needed by UK companies.

“Many firms have difficulties recruiting people with the right skills, and are having to pay a big premium for some skills. Although we can survey firms about their needs, the results can be misleading, not least because only a select group of companies may respond,” said Vignoles.

“I have been working with colleagues to accurately analyse graduate earnings, using anonymous Government administrative data. This type of analysis can show how earnings vary for different types of graduates, and so indicate which skills are in short supply.

“For example, let’s say that the next stage of our research reveals that graduates with strong analytical skills are in demand. This data could inform students, universities and policy makers, and may result in courses offering more training in analytical skills. More graduates will then have the analytical skills needed by businesses, and the skills gap should start to close.

“Of course, providing information is not enough to change policy, but without good data any policy development is likely to be ineffective. The UK is world-leading when it comes to education data, but it is only recently that a Big Data approach has been used to look at graduate earnings. Fully exploiting the Government’s education data could help to bridge the UK skills gap.

“However there should always be strict limitations on the way data is used to ensure that people’s privacy is protected. We need to have an informed debate about the extent to which members of the public are happy for data collected by the state to be used in this way.”

Vignoles sits on the steering group of the University of Cambridge’s Big Data Research Initiative. This brings together researchers to address challenges presented by access to unprecedented volumes of data, as well as important issues around law, ethics and economics, in order to apply Big Data to solve challenging problems for society.

Rustat Conferences are held three times a year at Jesus College, Cambridge, with this conference focusing on Big Data. Other sessions explored the Internet of Things, sharing data and respecting individual rights without disrupting new business models, and the legal aspects of Big Data. Rustat Conferences offer an opportunity for decision-makers from the frontlines of politics, business, finance, the media and education to discuss vital issues with leading academic experts.

The study, which could see over 500 students receive mindfulness training, aims to measure its effectiveness in managing stress amongst students, particularly at exam time, and whether it helps in other factors such as sleep and wellbeing. It will also explore whether the training affects students’ use of mental health treatment and support services.

Mindfulness involves the use of meditation techniques and self-awareness. Originally developed to help patients with chronic pain cope with their condition, it is now a recognised – and clinically-proven – way of helping individuals cope with depression, anxiety and stress.

Géraldine Dufour, Head of Counselling at the University, says: “University life can be stressful at time for students, as they develop the skills to live and study independently. Developing resilience and the skills to cope with stress is key so that students can make the most of life in the collegiate university and when they leave. The university counselling service offers many opportunities for students to develop their skills through an extensive programme of workshops, groups and individual counselling. We believe mindfulness could be a powerful tool to help them, in addition to the other counselling services we offer. This research project will help us determine if mindfulness is a good use of resources.”

From October, undergraduates and postgraduates at the University of Cambridge will be invited to register for a free, eight-week mindfulness training course called Mindfulness Skills for Students, which will be led by Dr Elizabeth English, the University’s Mindfulness Practitioner. The course is a group-based training programme based on the course bookMindfulness: A Practical Guide to Finding Peace in a Frantic World, by Mark Williams and Danny Penman, and adapted for Cambridge students. It consists of one 90-minute session and seven 75-minute sessions. Participants are also requested to do some home practice and reading every week.

Students will be allocated at random to two groups – one to receive training immediately, the second to be deferred twelve months. All students – both those who take the course and those whose training is deferred – will record their stress levels using a smartphone app during the exam period, while activity monitors will record their physical activity and sleep patterns.

“The academic year provides a very real ‘natural experiment’,” says Dr Julieta Galante from the Department of Psychiatry, who will carry out the research together with Professor Peter Jones. “Students receive training, practice at home, then face a ‘pressure point’ – their exams. We hope that our study will help us answer the question of whether the provision of mindfulness training, which we know to be effective in other settings, can help students throughout the year and particularly at exam time.”

The level of support available to students at Cambridge is unparalleled in most other universities. The University Counselling Service, one of the best funded in the country, includes counsellors as well as mental health advisors and supplements the support available to students from specialist staff in the colleges such as college nurses and chaplains. In the previous academic year, over 1,500 people were seen for counselling – this represents around one in 12 of the student population. Its Mindfulness Skills for Students programme is believed to be the largest such programme in any university.

Students wishing to register for the evaluation study of the Mindfulness Training Programme should visit the mindfulness website or emailmindfulstudentstudy@medschl.cam.ac.uk.

• www.facebook.com/mindfulstudentstudy
• twitter.com/MSSatUoC

The findings, published today (September 28) in the journal Nature Genetics, suggest that the reproductive cells or ‘eggs’ in a woman’s ovaries (known as oocytes) that repair damaged DNA more efficiently survive longer. This results in a later age at menopause, which marks the end of a woman’s reproductive lifetime. Previous research has shown that DNA is regularly damaged by age and by toxic substances such as cigarette smoke – hence women who smoke go through menopause 1-2 years earlier on average than non-smokers.

Our cells have many mechanisms to detect and repair such damage, but cells die when too much damage accumulates. DNA is also damaged and repaired during the production of eggs – therefore these genes might also act to enhance a woman’s pool of eggs which is set in early life.

In a collaboration involving scientists from 177 institutions worldwide, the authors undertook a genome-wide association study of almost 70,000 women of European ancestry.

“Many women today are choosing to have babies later in life, but they may find it difficult to conceive naturally because fertility starts to diminish at least 10 years before menopause,” said Dr Anna Murray from the University of Exeter, and the paper’s senior author. “Our research has substantially increased our understanding of how reproductive ageing in women happens, which we hope will lead to the development of new treatments to avoid early menopause.”

Dr John Perry from the Medical Research Council (MRC) Epidemiology Unit at the University of Cambridge co-led the study, and said: “We have known for some time that the age at which women go through menopause is partly determined by genes. This study now tells us that there are likely hundreds of genes involved, each altering menopause age by anything from a few weeks to a year. It is striking that genes involved in DNA repair have such an important influence on the age of menopause, which we think is due to their effect on how quickly a woman’s eggs are lost throughout her lifetime.”

The researchers also used these genetic findings to examine links between menopause and other health conditions. They predict that every one year later that menopause occurs increases the risk of developing breast cancer by 6%.

Dr Deborah Thompson from the Department of Public Health and Primary Care at the University of Cambridge also co-led this large international collaboration and said: “One particularly convincing finding was that going through menopause earlier reduces your chances of developing breast cancer and we think this is because these women have less exposure to the hormone oestrogen over their lifetime.”

The next step is to understand in more detail how the genetic variations found in this study are causing alterations in the timing of menopause. Uncovering these mechanisms will hopefully lead to better treatment for conditions linked to menopause, such as infertility and also improved understanding of the heath impact of menopause, such as risk of osteoporosis and heart disease.

Menopause usually occurs between ages 40 to 60 years old, indicated by the end of natural menstrual cycles and in many women by physical symptoms, such as hot flushes, disrupted sleep, and reduced energy levels. Natural menopause before the age of 40 is often called “primary ovarian insufficiency” and occurs in 1% of women.

Adapted from a University of Exeter press release.

Reference:
Felix R Day et al. ‘Large-scale genomic analyses link reproductive aging to hypothalamic signaling, breast cancer susceptibility and BRCA1-mediated DNA repair.’ Nature Genetics (2015). DOI: 10.1038/ng.3412. 

The small tumours concealed in the adrenal gland are “unmasked” in early pregnancy, when a sudden surge of hormones fires them into life, leading to raised blood pressure and causing risk to patients.

New research published today in the New England Journal of Medicine conducted by a team led by Professor Morris Brown, professor of clinical pharmacology at Cambridge University and a Fellow of Gonville & Caius College, identifies this small group of lurking tumours for the first time, and explains why they behave as they do.

The study means that, when patients are found to have high blood pressure early in pregnancy, doctors will now be encouraged to consider that the cause could be the tumours, which can be easily treated. Currently, adrenal tumours are not usually suspected as the cause of high blood pressure in pregnancy, and so go undiagnosed.

Brown and an international group of PhD students including first-author Ada Teo of Newnham College used a combination of state-of-the-art gene “fingerprinting” technology and old-fashioned deduction from patient case histories to work out that the otherwise benign tumours harbour genetic mutations that affect cells in the adrenal gland.

The mutation means the adrenal cells are given false information and their clock is effectively turned back to “childhood”, returning them to their original state as ovary cells. They then respond to hormones released in pregnancy, producing increased levels of the salt-regulating hormone aldosterone.

Aldosterone in turn regulates the kidneys to retain more salt and hence water, pushing up blood pressure. High blood pressure – also known as hypertension – can be fatal, since it greatly increases the risk of stroke and heart attack.

The new findings build on a growing body of research focusing on the adrenal gland and blood pressure. Sixty years ago, the American endocrinologist Dr Jerome Conn first observed that large benign tumours in the adrenal gland can release aldosterone and increase blood pressure (now known as Conn’s Syndrome).

Brown and his team have previously found a group of much smaller tumours, arising from the outer part of the gland, that have the same effect. The latest discovery drills down still further, revealing that roughly one in ten of this group has a mutation that makes the cells receptive to pregnancy hormones.

Brown said: “This is an example of what modern scientific techniques, and collaborations among doctors and scientists, allow you to do [through a form of genetic fingerprinting]. Conditions are often around for 60 years which we have had no explanation for, and now we can get to the heart of what has gone wrong.”

But the discovery also relied on what doctors call “clinical pattern recognition” – using experience to spot similarities. Brown was able to link together the cases of two pregnant women almost ten years apart and a woman in early menopause. All suffered high blood pressure, leading him to screen their adrenal tumours and identify a matching genetic mutation.

Pregnant women found to have the newly identified subset of tumours can now be identified more readily, and the tumours either treated with drugs or potentially even removed.

The research was funded by the Wellcome Trust, National Institute for Health Research, British Heart Foundation and A* Singapore.

In the animal kingdom, the flashiest males often have more luck attracting a mate. But when your predators hunt by sight, this can pose an interesting problem.

Like many species, lizards use bright colours for sexual signalling to attract females and intimidate rival males. A new study published in Ecology and Evolution by Kate Marshall from the University of Cambridge’s Department of Zoology and Martin Stevens from the University of Exeter’s Centre for Ecology and Conservation has provided evidence that this signalling comes at a cost.

Using models that replicated the colouration of male and female wall lizards found on the Greek islands of Skopelos and Syros, they found that the male lizard models were less well camouflaged against their habitat and more likely to fall prey to bird attacks.

Marshall, lead author of the study, explains: “we wanted to get to the origins of colour evolution; to find out what is causing colour variation between these lizards. We wanted to know whether natural selection favours camouflage, and whether the conflicting need to have bright sexual signals might impair its effectiveness.

“It has previously been assumed that conspicuous male colours are costly to survival, but this hasn’t been tested before among these specific lizards living on different islands, and in general rarely in a way that takes into account the particular sensitivities of avian vision.”

Birds see the world differently from you or I: they are able to see ultraviolet (UV) light whereas we cannot, which means they perceive colour (and camouflage) in a very different way. To test whether the males really are more visible to feathered predators, the researchers had to develop clay models that accurately replicated the lizards’ colour to a bird’s eye.

Using visual modelling, Marshall and her colleagues painstakingly tested around 300 colour variations to find ones that matched the male and female colours in order to make the 600 clay lizards used in the study.

Marshall comments: “it was important to get a clay colour that would be indistinguishable from a real lizard to a bird’s eyes: we even tried using a paint colour chart, but they all reflected too much UV. To us the models may not look like very good likenesses, but to a bird the models should have looked the same colour as the real lizards.”

Marshall and her field assistant, Kate Philpot, placed the male and female lizard models in ten sites on each of the two islands and checked them every 24 hours over five days to see which had been attacked by birds.

“The models that had been attacked showed signs of beak marks, particularly around the head, and some had been decapitated,” explains Marshall. “We even found a few heads in different fields to the bodies.”

“The fact that the birds focused their attacks on the heads of the models also shows us that they perceived them as real lizards because that is how they would attack real prey,” she adds.

At the end of the study, the researchers found that the models with male colouration had been attacked more than the models with female colouration.

Marshall and the team also tested how conspicuous the models were against their real backgrounds using further modelling of avian vision, and found that the male models were less camouflaged than the females.

“In females, selection seems to have favoured better camouflage to avoid attack from avian predators. But in males, being bright and conspicuous also appears to be important even though this heightens the risk of being spotted by birds,” says Marshall.

However, it is not entirely a tale of woe for the male Aegean wall lizard. Despite being attacked more than the females by predatory birds, 83% of the male lizard models survived over the course of the five-day experiment. Marshall explains that this may indicate that males have colour adaptations that balance the contradictory needs to attract a mate and to avoid becoming lunch.

“In past work we’ve found these lizards have evolved bright colours on their sides, which are more visible to other lizards on the ground than to birds hunting from above,” explains Marshall. “The visual system of lizards is different again from birds, such as through increased sensitivity to UV, so the colour on their backs is more obvious to other lizards than to birds. Such selective “tuning” of colours to the eyes of different observers might provide at least some camouflage against dangerous predators that sneakily eavesdrop on the bright signals of their prey.”

“With these models we were only able to replicate the overall colour of the lizards rather than their patterns, so it would be interesting to investigate further whether these patterns affect the survival rates of lizard models,” she adds. “It would also be great to apply this type of experiment to other questions, such as how different environments affect the amount of predation that prey animals experience.”

Reference: Marshall, K et al. “Conspicuous male coloration impairs survival against avian predators in Aegean wall lizards, Podarcis erhardii” Ecology and Evolution (September 2015). DOI: http://onlinelibrary.wiley.com/doi/10.1002/ece3.1650/full

The research was enabled by funding from the Biotechnology and Biological Sciences Research Council, the British Herpetological Society, the Cambridge Philosophical Society, and Magdalene College, Cambridge.

Inset images: Tetrahedral plot of avian vision (Kate Marshall et al); Models showing signs of bird attack (Kate Marshall et al); Males, females and their corresponding models (Kate Marshall et al).

Increased greenhouse gas emissions from the release of carbon dioxide and methane contained in the Arctic permafrost could result in $43 trillion in additional economic damage by the end of the next century, according to researchers from the University of Cambridge and the University of Colorado.

In a letter published today (21 September) in the journal Nature Climate Change, the researchers have for the first time modelled the economic impact caused by melting permafrost in the Arctic to the end of the twenty-second century, on top of the damage already predicted by climate and economic models.

The Arctic is warming at a rate which is twice the global average, due to anthropogenic, or human-caused, greenhouse gas emissions. If emissions continue to rise at their current rates, Arctic warming will lead to the widespread thawing of permafrost and the release of hundreds of billions of tonnes of methane and CO₂ – about 1,700 gigatonnes of carbon are held in permafrost soils in the form of frozen organic matter.

Rising emissions will result in both economic and non-economic impacts, as well as a higher chance of catastrophic events, such as the melting of the Greenland and West Antarctic ice sheets, increased flooding and extreme weather. Economic impacts directly affect a country’s gross domestic product (GDP), such as the loss of agricultural output and the additional cost of air conditioning, while non-economic impacts include effects on human health and ecosystems.

The researchers’ models predict $43 trillion in economic damage could be caused by the release of these greenhouse gases, an amount equivalent to more than half the current annual output of the global economy. This brings the total predicted impact of climate change by 2200 to $369 trillion, up from $326 trillion – an increase of 13 percent.

“These results show just how much we need urgent action to slow the melting of the permafrost in order to minimise the scale of the release of greenhouse gases,” said co-author Dr Chris Hope from the Cambridge Judge Business School.

Hope’s calculations were conducted in collaboration with Kevin Schaefer of the National Snow and Ice Data Center at the University of Colorado.

Hope and Schaefer used the PAGE09 (Policy Analysis of the Greenhouse Effect) integrated assessment model to measure the economic impact of permafrost thawing on top of previous calculations of the climate change costs of business-as-usual greenhouse gas emissions from the Intergovernmental Panel on Climate Change (IPCC).

“We want to use these models to help us make better decisions – linking scientific and economic models together is a way to help us do that,” said Hope. “We need to estimate how much it will cost if we do nothing, how much it will cost if we do something, and how much we need to spend to cut back greenhouse gases.”

The researchers say that if an aggressive strategy to reduce emissions from thawing permafrost is adopted, it could reduce the impact by as much as $37 trillion.

Reference:
Hope, C. and Schaefer, K. ‘Economic impacts of carbon dioxide and methane released from thawing permafrost’. Nature Climate Change (2015). DOI: 10.1038/nclimate2807

Analysis of the London Tube strike in February 2014 has found that despite the inconvenience to tens of thousands of people, the strike actually produced a net economic benefit, due to the number of people who found more efficient ways to get to work.

The researchers, from the University of Cambridge and the University of Oxford, examined 20 days’ worth of anonymised Oyster card data, containing more than 200 million data points, in order to see how individual Tube journeys changed during the strike. Since this particular strike only resulted in a partial closure of the Tube network and not all commuters were affected by the strike, a direct comparison was possible. The data enabled the researchers to see whether people chose to go back to their normal commute once the strike was over, or if they found a more efficient route and decided to switch.

The researchers found that of the regular commuters affected by the strike, either because certain stations were closed or because travel times were considerably different, a significant fraction – about one in 20 – decided to stick with their new route once the strike was over.

While the proportion of individuals who ended up changing their routes may sound small, the researchers found that the strike actually ended up producing a net economic benefit. By performing a cost-benefit analysis of the amount of time saved by those who changed their daily commute, the researchers found that the amount of time saved in the longer term actually outweighed the time lost by commuters during the strike. An Oxford working paper of their findings is published online today.

The London Tube map itself may have been a reason why many commuters did not find their optimal journey before the strike. In many parts of London, the actual distances between stations are distorted on the iconic map. By digitising the Tube map and comparing it to the actual distances between stations, the researchers found that those commuters living in, or travelling to, parts of London where distortion is greatest were more likely to have learned from the strike and found a more efficient route.

Additionally, since different Tube lines travel at different speeds, those commuters who had been travelling on one of the slower lines were also more likely to switch routes once the strike was over.

“One of the things we’re looking at is whether consumers usually make the best decision, but it’s never been empirically tested using a large consumer dataset such as this one,” said co-author Dr Ferninand Rauch from Oxford’s Department of Economics. “Our findings illustrate that people might get stuck with suboptimal decisions because they don’t experiment enough.”

According to the authors, being forced to alter a routine, whether that’s due to a Tube strike or government regulation, can often lead to net benefits, as people or corporations are forced to innovate. In economics, this is known as the Porter hypothesis.

“For the small fraction of commuters who found a better route, when multiplied over a longer period of time, the benefit to them actually outweighs the inconvenience suffered by many more,” said co-author Dr Shaun Larcom of Cambridge’s Department of Land Economy. “The net gains came from the disruption itself.”

“Given that a significant fraction of commuters on the London underground failed to find their optimal route until they were forced to experiment, perhaps we should not be too frustrated that we can’t always get what we want, or that others sometimes take decisions for us,” said co-author Dr Tim Willems, also from Oxford’s Department of Economics. “If we behave anything like London commuters and experiment too little, hitting such constraints may very well be to our long-term advantage.”

Reference:
Larcom, Shaun, Ferdinand Rauch and Tim Willems (2015), “The Benefits of Forced Experimentation: Striking Evidence from the London Underground Network”, University of Oxford Working Paper. 

Spironolactone, one of a range of drugs given according to doctors’ preference to patients with resistant hypertension (high blood pressure that doesn’t respond to a standard drug treatment), is in fact “outstandingly superior” to the alternatives, researchers have found. They recommend it should now be the first choice for such patients, and say that – for most – this well-known but under-valued drug will bring their condition fully under control.

The discovery could have a profound impact globally, since hypertension, a major contributor to stroke and heart disease, is so common, affecting as many as one in three adults in some countries. It challenges what the authors describe as “a growing perception” that severe hypertension was beyond the control of existing drug treatments, and gives more clues into what causes the condition.

The latest research, published today in the Lancet to coincide with their presentation to the British Hypertension Society, emerged from the PATHWAY-2 trial, part of the PATHWAY programme of trials in hypertension funded by the British Heart Foundation and led by Professor Morris Brown, professor of clinical pharmacology at Cambridge University and a Fellow of Gonville & Caius College.

The findings are drawn from what authors Brown and Professor Bryan Williams of University College London describe as an experimental “shoot-out” between three different drugs used by doctors for years to treat patients if the standard initial cocktail of three hypertension drugs do  not work.

Spironolactone ‘slugged it out’ against a betablocker (bisoprolol) and an alpha-blocker (doxazosin) in the trial, which took six years and involved 314 patients in 14 different centres.

The patients all suffered from resistant high blood pressure that had not responded to the standard treatment for hypertension: a combination of three drugs (an ACE-inhibitor (or angiotensin-receptor blocker), a calcium channel blocker and a thiazide-type diuretic). They continued with this basic combination thoughout, but each of the three trial drugs – and a placebo – was added one at a time, in random order, for 12 weeks each.

In what is known as a “double blind” trial, neither the patients nor the researchers knew which patient was taking which drug when. In a pioneering step, the study also used patients’ own blood pressure readings taken at home to minimise so-called “white coat syndrome”, in which the stress of being in a clinic causes blood pressure to rise artificially.

Once the resulting data had been analysed, it emerged that almost three quarters of patients in the trial saw a major improvement in blood pressure on spironolactone, with almost 60% hitting a particularly stringent measure of blood pressure control. Of the three drugs trialled, spironolactone was the best at lowering blood pressure in 60% of patients, whereas bisoprolol and doxazosin were the best drug in only 17% and 18% respectively.

“Spironolactone annihilated the opposition,” said Brown. “Most patients came right down to normal blood pressure while taking it.”

He added: “This is an old drug which has been around for a couple of generations that has resurfaced and is almost a wonder drug for this group of patients. In future it will stimulate us to look for these patients at a much earlier stage so we can treat and maybe even cure them before resistant hypertension occurs.”

Doctors appear to have been wary of giving patients spironolactone because it raises the level of potassium in the body. But the study revealed the rise to be only marginal and not dangerous.

The causes of resistant of hypertension are still poorly understood, but one theory is that the condition could be the result of sodium retention: too much salt in the body.

Spironolactone is a diuretic and helps the body get rid of salt. In the trial, it worked even better than average on patients whom tests showed had high salt levels. Brown said the findings appeared to confirm that, in most patients with resistant hypertension, excessive salt was the problem, probably caused by too much of the adrenal hormone aldosterone.

Instead of seeing the treatment-resistant form of high blood pressure as simply the result of having the condition for a long time or of poor treatment, it should be regarded as a different sub-group of hypertension which would need different investigations and treatments, Brown said.

An artificial pancreas given to children and adults with type 1 diabetes going about their daily lives has been proven to work for 12 weeks – meaning the technology, developed at the University of Cambridge, can now offer a whole school term of extra freedom for children with the condition.

Artificial pancreas trials for people at home, work and school have previously been limited to short periods of time. But a study, published today in the New England Journal of Medicine, saw the technology safely provide three whole months of use, bringing us closer to the day when the wearable, smartphone-like device can be made available to patients.

The lives of the 400,000 UK people with type 1 diabetes currently involves a relentless balancing act of controlling their blood glucose levels by finger-prick blood tests and taking insulin via injections or a pump. But the artificial pancreas sees tight blood glucose control achieved automatically.

This latest Cambridge study showed the artificial pancreas significantly improved control of blood glucose levels among participants – lessening their risk of hypoglycaemia. Known as ‘having a hypo,’ hypoglycaemia is a drop in blood glucose levels that can be highly dangerous and is what people with type 1 diabetes hate most.

Susan Walls is mother to Daniel Walls, a 12-year-old with type 1 diabetes who has taken part in the trial. She said: “Daniel goes back to school this month after the summer holidays – so it’s a perfect time to hear this wonderful news that the artificial pancreas is proving reliable, offering a whole school term of support.

“The artificial pancreas could change my son’s life, and the lives of so many others. Daniel has absolutely no hypoglycaemia awareness at night. His blood glucose levels could be very low and he wouldn’t wake up. The artificial pancreas could give me the peace of mind that I’ve been missing.”

“The data clearly demonstrate the benefits of the artificial pancreas when used over several months,” said Dr Roman Hovorka, Director of Research at the University’s Metabolic Research Laboratories, who developed the artificial pancreas. “We have seen improved glucose control and reduced risk of unwanted low glucose levels.”

The Cambridge study is being funded by JDRF, the type 1 diabetes charity. Karen Addington, Chief Executive of JDRF, said: “JDRF launched its goal of perfecting the artificial pancreas in 2006. These results today show that we are thrillingly close to what will be a breakthrough in medical science.”

Reference:
Thabit, Hood et al. ‘Free-living Home Use of an Artificial Beta Cell in Type 1 Diabetes.’ New England Journal of Medicine (2015). DOI: 10.1056/NEJMoa1509351

Adapted from a JDRF press release.

At a time of global focus on refugee issues due to the war in Syria and other displacement, new research from the University of Cambridge calls for policymakers to foster entrepreneurship at refugee camps to help fill an ‘institutional void’ that leads to despair, boredom and crime.

Although most refugee camps are initially set up to provide supposedly “temporary” safety for people uprooted by war, natural disaster or other events, the reality is that many forcibly displaced people spend 20 years or more in exile.

A paper from Cambridge researchers calls on governments and other policymakers to promote refugee-camp entrepreneurship in order to provide an economic and psychological boost to displaced people.

“Refugee camp entrepreneurs reduce aid dependency and in so doing help to give life meaning for, and confer dignity on, the entrepreneurs,” says the paper, by Marlen de la Chaux, a PhD student at the Cambridge Judge Business School, and Helen Haugh, Senior Lecturer in Community Enterprise at Cambridge Judge. Marlen is a Gates Cambridge Scholar.

While such camps are created on the assumption they will be temporary in response to a passing emergency, such displacement is in fact often protracted – so “the rules of the game concerning temporary institutions do not reflect the reality of life in the camp,” the paper says.

The paper – entitled “Entrepreneurship and Innovation: How Institutional Voids Shape Economic Opportunities in Refugee Camps” – was presented by the authors at this summer’s 75th Annual Meeting of the Academy of Management in Vancouver, Canada.

The researchers identify three institutional barriers to refugee camp entrepreneurship: a lack of functioning markets, inefficient legal and political systems, and poor infrastructure.

This presents a number of opportunities for policymakers to boost entrepreneurship opportunities, including urban planning techniques to design useful infrastructure because long-term refugee camps tend to resemble small cities rather than transient settlements.

In addition, cash-based aid programmes and partnerships between refugee camp organisers and micro-lending institutions can provide seed capital to refugee camp ventures; innovation hubs such as those recently established in Nairobi, Kenya, can help provide access to business advice and seed capital; and the host country can create employment opportunities within the refugee camp by outsourcing some tasks to refugees.

“As the number of forcibly displaced increases, the urgency to find solutions to redress the negative aspects of life in a refugee camp for those in protracted exile also rises,” the paper says. Enlightened policies to boost refugee-camp entrepreneurship “may also make a positive contribution to the economy of the host country and in so doing help to reduce the local resentment experienced by those living in camps.”

Adapted from an article originally published on the Cambridge Judge Business School website.

Scientists have identified an ingeniously elegant brain circuit consisting of just five nerve cells that allows female crickets to automatically identify the chirps of males from the same species through the rhythmic pulses hidden within the mating call.

The circuit uses a time delay mechanism to match the gaps between pulses in a species-specific chirp – gaps of just few milliseconds. The circuit delays a pulse by the exact between-pulse gap, so that, if it coincides with the next pulse coming in, the same species signal is confirmed.

It’s one of the first times a brain circuit consisting of individual neurons that identifies an acoustic rhythm has been characterised. The results are reported today (11 September) in the journal Science Advances.

Using tiny electrodes, scientists from Cambridge University’s Department of Zoology explored the brain of female crickets for individual auditory neurons responding to digitally-manipulated cricket chirps (even a relatively simple organism such as a cricket still has a brain containing up to a million neurons).

Once located, the nerve cells were stained with fluorescent dye. By monitoring how each neuron responded to the sound pulses of the cricket chirps, scientists were able to work out the sequence the neurons fired in, enabling them to unpick the time delay logic of the circuit.

Sound processing starts in hearing organs, but the temporal, rhythmic features of sound signals – vital to all acoustic communication from birdsong to spoken language – are processed in the central auditory system of the brain.

Scientists say that the simple, time-coded neural network discovered in the brain of crickets may be an example of fundamental neural circuitry that identifies sound rhythms and patterns, and could be the basis for “complex and elaborate neuronal systems” in vertebrates.

“Compared to our complex language, crickets only have a few songs which they have to recognise and process, so, by looking at their much simpler brain, we aim to understand how neurons process sound signals,” said senior author Dr Berthold Hedwig.

Like in Morse code, contained within each cricket chirp are several pulses, interspersed by gaps of a few milliseconds. It’s the varying length of the gaps between pulses that is each species’ unique rhythm.

It is this ‘Morse code’ that gets read by the five-neuron circuit in the female brain.

Crickets’ ears are located on their front legs. On hearing a sound like a chirp, nerve cells respond and carry the information to the thoracic segment, and on to the brain.

Once there, the auditory circuit splits and sends the information into two branches:

One branch (consisting of two neurons) acts as a delay line, holding up the processing of the signal by the same amount of time as the interval between pulses – a mechanism specific to a cricket species’ chirp. The other branch sends the signal straight through to a ‘coincidence detector’ neuron.

When a second pulse comes in, it too is split, and part of the signal goes straight through to the coincidence detector. If the second pulse and the delayed signal from the first pulse ‘coincide’ within the detector neuron, then the circuit has a match for the pulse time-code within the chirp of their species, and a final output neuron fires up, when the female listens to the correct sound pattern.

“Once the circuit has a second pulse, it can define the rhythm. The first pulse is initial excitation; the second pulse is then superimposed with the delayed part of the first. The output neuron only produces a strong response if the pulses collide at the coincidence detector, meaning the timing is locked in, and the mating call is a species match,” said Hedwig.

“With hindsight, I would say it’s impossible to make the circuitry any simpler – it’s the minimum number of elements that are required to do the processing. That’s the beauty of nature, it comes up with the most simple and elegant ways of dealing with and processing information,” he said.

To find the most effective sound pattern, the scientists digitally manipulated the natural pulse patterns and played the various patterns to female crickets mounted atop a trackball inside an acoustic chamber containing precisely located speakers.

If a particular rhythm of pulses triggered the female to set off in the direction of that speaker, the trackball recorded reaction times and direction.

Once they had honed the pulse patterns, the team played them to female crickets in modified mini-chambers with opened-up heads and brains exposed for the experiments.

Microelectrodes allowed them to record the key auditory neurons (“it takes a couple of hours to find the right neuron in a cricket brain”), tag and dye them, and piece together the neural circuitry that reads rhythmic pulses occurring at intervals of few milliseconds in male cricket chirps.

Added Hedwig: “Through this series of experiments we have identified a delay mechanism within a neuronal circuit for auditory processing – something that was first hypothesised over 25 years ago. This time delay circuitry could be quite fundamental as an example for other types of neuronal processing in other, perhaps much larger, brains as well.”

The research was funded by the Biotechnology and Biological Sciences Research Council (BBSRC).

Reference:
Stefan Schöneich, Konstantinos Kostarakos, Berthold Hedwig. An auditory feature detection circuit for sound pattern recognition. Science Advances (2015). DOI: 10.1126/sciadv.1500325

A new study conducted in collaboration with Facebook using anonymised data from the social networking site shows a correlation between people’s social and financial status, and the levels of internationalism in their friendship networks – with those from higher social classes around the world having fewer friends outside of their own country.

Despite the fact that, arguably, people from higher social classes should be better positioned to travel and meet people from different countries, researchers found that, when it comes to friendship networks, people from those groups had lower levels of internationalism and made more friends domestically than abroad.

Researchers say that their results are in line with what’s known as the ‘restricting social class’ hypothesis: that high-social class individuals have greater resources, and therefore depend less on others – with the wealthy tending to be less socially engaged, particularly with those from groups other than their own, as a result.

The research team, from the Prosociality and Well-Being Lab in the University of Cambridge’s Department of Psychology, conducted two studies – one local and one global, with the global study using a dataset of billions of Facebook friendships – and the results from both supported the idea of restricting social class.

However, the researchers say the fact that those of lower social status tend to have more international connections demonstrates how low-social class people “may actually stand to benefit most from a highly international and globalised social world”.

“The findings point to the possibility that the wealthy stay more in their own social bubble, but this is unlikely to be ultimately beneficial. If you are not engaging internationally then you will miss out on that international resource – that flow of new ideas and information,” said co-author Dr Aleksandr Spectre, who heads up the lab.

“The results could also be highlighting a mechanism of how the modern era might facilitate a closing of the inequality gap, as those from lower social classes take advantage of platforms like Facebook to increase their social capital beyond national borders,” he said.

For the first study, the ‘local’, the team recruited 857 people in the United States and asked them to self-report their perceived social status (from working to upper class on a numerical scale), as well as an objective indicator in the form of annual household income. The volunteers also provided researchers access to their Facebook networks.

The results from the first study indicated that low-social class people have nearly 50% more international friends than high-social class people.

For the second study, the ‘global’, the team approached Facebook directly, who provided data on every friendship formed over the network in every country in the world at the national aggregate level for 2011. All data was anonymous. The dataset included over 57 billion friendships.

The research team quantified social class on a national level based on each country’s economic standing by using gross domestic product (GDP) per capita data for 2011 as published by the World Bank.

After controlling for as many variables as they were able, the researchers again found a negative correlation between social class – this time on a national level – and the percentage of Facebook friends from other countries. For people from low-social class countries, 35% of their friendships on average were international, compared to 28% average in high-social class countries.

The findings from the two studies provide support for the restricting social class hypothesis on both a local and a global level, say the researchers. The results are contained in a new paper, published in the journal Personality and Individual Differences.

“Previous research by others has highlighted the value of developing weak ties to people in distant social circles, because they offer access to resources not likely to be found in one’s immediate circle. I find it encouraging that low-social class people tend to have greater access to these resources on account of having more international friendships,” said co-author Maurice Yearwood.

“From a methodological perspective, this combination of micro and macro starts to build a very interesting initial story. These are just correlations at the moment, but it’s a fascinating start for this type of research going forward,” Yearwood said.

Spectre says that the high levels of Facebook usage and sheer size of the network makes it a “pretty good proxy for your social environment”. “The vast majority of Facebook friendships are ones where people have met in person and engaged with each other, a lot of the properties you find in Facebook friendship networks will strongly mirror everyday life,” he said.

“We are entering an era with big data and social media where we can start to ask really big questions and gain answers to them in a way we just couldn’t do before. I think this research is a good example of that, I don’t know how we could even have attempted this work 10 years ago,” Spectre said.

The latest work is the first output of ongoing research collaborations between Spectre’s lab in Cambridge and Facebook, a company he commends for its “scientific spirit”.  “Having the opportunity to work with companies like Facebook, Twitter, Microsoft and Google should be something that’s hugely exciting to the academic community,” he said.

Reference:
Yearwood, M. H., Cuddy, A., Lamba, N., Youyou, W., van der Lowe, I., Piff, P., Gronin, C., Fleming, P., Simon-Thomas, E., Keltner, D., & Spectre, A. (2015). On wealth and the diversity of friendships: High social class people around the world have fewer international friends. Personality and Individual Differences, 87, 224-229. DOI: doi:10.1016/j.paid.2015.07.040

The study, which compares spoken English today with recordings from the 1990s, allows researchers at Cambridge University Press and Lancaster University to examine how the language we use indicates our changing attitudes to education.

They found that the topic of education is far more salient in conversations now, with the word cropping up 42 times per million words, compared with only 26 times per million in the 1990s dataset.

As well as talking about education more, there has also been a noticeable shift in the terms we use to describe it. Twenty years ago, the public used fact-based terms to talk about education, most often describing it as either full-time, or part-time.

Today, however, we’re more likely to use evaluative language about the standards of education and say that it’s good, bad or great. This could be due to the rise in the formal assessments of schools, for example, with the establishment of the Office for Standards in Education, Children’s Services and Skills (OFSTED) in 1992. Indeed, Ofsted itself has made its debut as a verb in recent times, with the arrival of discussions on what it means for a school to be Ofsteded.

Dr Claire Dembry, Senior Language Research Manager at Cambridge University Press said: “It’s fascinating to find out that, not only do we talk about education twice as much as we used to, but also that we are more concerned about the quality. It’s great that we have these data sets to be able to find out these insights; without them we wouldn’t be able to research how the language we use is changing, nor the topics we talk about most.”

The research findings also indicate that we’re now expecting to get more out of our education than we used to. We’ve started talking about qualifications twice as much as we did in the 1990s, GCSEs five times as much and A levels 1.4 times as much.

Meanwhile, use of the word university has tripled. This is perhaps not surprising, as the proportion of young people going to university doubled between 1995 and 2008, going from 20 per cent to almost 40 per cent.

When the original data was collected in the 1990s, university fees had yet to be introduced, and so it is unsurprising that the terms university fees and tuition fees did not appear in the findings. However the recent data shows these terms to each occur roughly once per million words, as we’ve begun to talk about university in more commercialised terms.

However, while teachers may be happy to hear that education is of growing concern to the British public, it won’t come as good news to them that the adjective underpaid is most closely associated with their job.

These are only the initial findings from the first two million words of the project, named the ‘Spoken British National Corpus 2014,’ which is still seeking recorded submissions.

Professor Tony McEnery, from the ESRC Centre for Corpus Approaches to Social Sciences (CASS) at Lancaster University, said: “We need to gather hundreds, if not thousands, of conversations to create a full spoken corpus so we can continue to analyse the way language has changed over the last 20 years.

“This is an ambitious project and we are calling for people to send us MP3 files of their everyday, informal conversations in exchange for a small payment to help me and my team to delve deeper into spoken language and to shed more light on the way our spoken language changes over time.”

People who wish to submit recordings to the research team should visit: http://languageresearch.cambridge.org/index.php/spoken-british-national-…