Revolutionary solar cells double as lasers

Latest research finds that the trailblazing ‘perovskite’ material used in solar cells can double up as a laser, strongly suggesting the astonishing efficiency levels already achieved in these cells is only part of the journey.Commercial silicon-based solar cells — such as those seen on the roofs of houses across the country — operate at about 20% efficiency for converting the Sun’s rays into electrical energy. It’s taken over 20 years to achieve that rate of efficiency.A relatively new type of solar cell based on a perovskite material — named for scientist Lev Perovski, who first discovered materials with this structure in the Ural Mountains in the 19th century — was recently pioneered by an Oxford research team led by Professor Henry Snaith.Perovskite solar cells, the source of huge excitement in the research community, already lie just a fraction behind commercial silicon, having reached a remarkable 17% efficiency after a mere two years of research — transforming prospects for cheap large-area solar energy generation.Now, researchers from Professor Sir Richard Friend’s group at Cambridge’s Cavendish Laboratory — working with Snaith’s Oxford group — have demonstrated that perovskite cells excel not just at absorbing light but also at emitting it. The new findings, recently published online in the Journal of Physical Chemistry Letters, show that these ‘wonder cells’ can also produce cheap lasers.By sandwiching a thin layer of the lead halide perovskite between two mirrors, the team produced an optically driven laser which proves these cells “show very efficient luminescence” — with up to 70% of absorbed light re-emitted.The researchers point to the fundamental relationship, first established by Shockley and Queisser in 1961, between the generation of electrical charges following light absorption and the process of ‘recombination’ of these charges to emit light.Essentially, if a material is good at converting light to electricity, then it will be good at converting electricity to light. The lasing properties in these materials raise expectations for even higher solar cell efficiencies, say the Oxbridge team, which — given that perovskite cells are about to overtake commercial cells in terms of efficiency after just two years of development — is a thrilling prospect.”This first demonstration of lasing in these cheap solution-processed semiconductors opens up a range of new applications,” said lead author Dr Felix Deschler of the Cavendish Laboratory. “Our findings demonstrate potential uses for this material in telecommunications and for light emitting devices.”Most commercial solar cell materials need expensive processing to achieve a very low level of impurities before they show good luminescence and performance. Surprisingly these new materials work well even when very simply prepared as thin films using cheap scalable solution processing.The researchers found that upon light absorption in the perovskite two charges (electron and hole) are formed very quickly — within 1 picosecond — but then take anywhere up to a few microseconds to recombine. This is long enough for chemical defects to have ceased the light emission in most other semiconductors, such as silicon or gallium arsenide. “These long carrier lifetimes together with exceptionally high luminescence are unprecedented in such simply prepared inorganic semiconductors,” said Dr Sam Stranks, co-author from the Oxford University team.”We were surprised to find such high luminescence efficiency in such easily prepared materials. This has great implications for improvements in solar cell efficiency,” said Michael Price, co-author from the group in Cambridge.Added Snaith: “This luminescent behaviour is an excellent test for solar cell performance — poorer luminescence (as in amorphous silicon solar cells) reduces both the quantum efficiency (current collected) and also the cell voltage.”Scientists say that this new paper sets expectations for yet higher solar cell performance from this class of perovskite semiconductors. Solar cells are being scaled up for commercial deployment by the Oxford spin-out, Oxford PV Ltd. …

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Stopping smoking linked to improved mental health

The researchers say the effect sizes are equal or larger than those of antidepressant treatment for mood and anxiety disorders.It is well known that stopping smoking substantially reduces major health risks, such as the development of cancers, cardiovascular and respiratory diseases. But the association between smoking and mental health is less clear cut.Many smokers want to stop but continue smoking as they believe smoking has mental health benefits. And health professionals are sometimes reluctant to deal with smoking in people with mental disorders in case stopping smoking worsens their mental health.So researchers from the universities of Birmingham, Oxford, and King’s College London set out to investigate changes in mental health after smoking cessation compared with continuing to smoke.They analysed the results of 26 studies of adults that assessed mental health before smoking cessation and at least six weeks after cessation in the general population and clinical populations (patients with chronic psychiatric and/or physical conditions).Differences in study design and quality were taken into account to minimize bias.Measures of mental health included anxiety, depression, positivity, psychological quality of life, and stress. Participants had an average age of 44, smoked around 20 cigarettes a day, and were followed up for an average of six months.The research team found consistent evidence that stopping smoking is associated with improvements in depression, anxiety, stress, psychological quality of life, and positivity compared with continuing to smoke.The strength of association was similar for both the general population and clinical populations, including those with mental health disorders. And there was no evidence that study differences could have skewed the results.Although observational data can never prove causality, “smokers can be reassured that stopping smoking is associated with mental health benefits,” say the authors.”This could overcome barriers that clinicians have toward intervening with smokers with mental health problems,” they add. “Furthermore, challenging the widely held assumption that smoking has mental health benefits could motivate smokers to stop.”Story Source:The above story is based on materials provided by BMJ-British Medical Journal. Note: Materials may be edited for content and length.

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Seven new genetic regions linked to type 2 diabetes

Seven new genetic regions associated with type 2 diabetes have been identified in the largest study to date of the genetic basis of the disease.DNA data was brought together from more than 48,000 patients and 139,000 healthy controls from four different ethnic groups. The research was conducted by an international consortium of investigators from 20 countries on four continents, co-led by investigators from Oxford University’s Wellcome Trust Centre for Human Genetics.The majority of such ‘genome-wide association studies’ have been done in populations with European backgrounds. This research is notable for including DNA data from populations of Asian and Hispanic origin as well.The researchers believe that, as more genetic data increasingly become available from populations of South Asian ancestry and, particularly, African descent, it will be possible to map genes implicated in type 2 diabetes ever more closely.’One of the striking features of these data is how much of the genetic variation that influences diabetes is shared between major ethnic groups,’ says Wellcome Trust Senior Investigator Professor Mark McCarthy from the University of Oxford. ‘This has allowed us to combine data from more than 50 studies from across the globe to discover new genetic regions affecting risk of diabetes.’He adds: ‘The overlap in signals between populations of European, Asian and Hispanic origin argues that the risk regions we have found to date do not explain the clear differences in the patterns of diabetes between those groups.’Among the regions identified by the international research team are two, near the genes ARL15 and RREB1, that also show strong links to elevated levels of insulin and glucose in the body — two key characteristics of type 2 diabetes. This finding provides insights into the ways basic biochemical processes are involved in the risk of type 2 diabetes, the scientists say.The genome-wide association study looked at more than 3 million DNA variants to identify those that have a measurable impact on risk of type 2 diabetes. By combining DNA data from many tens of thousands of individuals, the consortium was able to detect, for the first time, regions where the effects on diabetes susceptibility are rather subtle.’Although the genetic effects may be small, each signal tells us something new about the biology of the disease,’ says first author Dr Anubha Mahajan of Oxford University. ‘These findings may lead us to new ways of thinking about the disease, with the aim ultimately of developing novel therapies to treat and prevent diabetes. There’s every reason to expect that drugs acting on these biological processes would have a far larger impact on an individual’s diabetes than the genetic effects we have discovered.’Principal investigator Dr Andrew Morris, also of the Wellcome Trust Centre for Human Genetics at Oxford University, says: ‘The findings of our study should also be relevant to other common human diseases. By combining genetic data from different ethnic groups, we would expect also to be able identify new DNA variants influencing risk of heart disease and some forms of cancer, for example, which are shared across ethnic groups. It has the potential to have a major impact on global public health.’Story Source:The above story is based on materials provided by University of Oxford. …

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Genes linked to being right- or left-handed identified

Sep. 12, 2013 — A genetic study has identified a biological process that influences whether we are right handed or left handed.Scientists at the Universities of Oxford, St Andrews, Bristol and the Max Plank Institute in Nijmegen, the Netherlands, found correlations between handedness and a network of genes involved in establishing left-right asymmetry in developing embryos.’The genes are involved in the biological process through which an early embryo moves on from being a round ball of cells and becomes a growing organism with an established left and right side,’ explained first author William Brandler, a PhD student in the MRC Functional Genomics Unit at Oxford University.The researchers suggest that the genes may also help establish left-right differences in the brain, which in turn influences handedness.They report their findings in the open-access journal PLOS Genetics.Humans are the only species to show such a strong bias in handedness, with around 90% of people being right-handed. The cause of this bias remains largely a mystery.The researchers, led by Dr Silvia Paracchini at the University of St Andrews, were interested in understanding which genes might have an influence on handedness, in order to gain an insight into the causes and evolution of handedness.The team carried out a genome-wide association study to identify any common gene variants that might correlate with which hand people prefer using.The most strongly associated, statistically significant variant with handedness is located in the gene PCSK6, which is involved in the early establishment of left and right in the growing embryo.The researchers then made full use of knowledge from previous studies of what PCSK6 and similar genes do in mice to reveal more about the biological processes involved.Disrupting PCSK6 in mice causes ‘left-right asymmetry’ defects, such as abnormal positioning of organs in the body. They might have a heart and stomach on the right and their liver on the left, for example.The researchers found that variants in other genes known to cause left-right defects when disrupted in mice were more likely to be associated with relative hand skill than you would expect by chance.While the team has identified a role for genes involved in establishing left from right in embryo development, William Brandler cautioned that these results do not completely explain the variation in handedness seen among humans. He said: ‘As with all aspects of human behaviour, nature and nurture go hand-in-hand. The development of handedness derives from a mixture of genes, environment, and cultural pressure to conform to right-handedness.’

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New insight into how Cheetahs catch their prey

Sep. 5, 2013 — A new research study has revealed that the cheetah, the world’s fastest land animal, matches and may even anticipate the escape tactics of different prey when hunting, rather than just relying on its speed and agility as previously thought.The study, which has just been published in the Royal Society Journal Biology Letters was carried out by a team of researchers from Queen’s University Belfast, in collaboration with other Institutions in the UK (University of Aberdeen, University of Swansea, Institute of Zoology, Zoological Society of London, University of Oxford), and elsewhere (North Carolina State University, The Lewis Foundation, South African National Parks, Earth and OCEAN Technologies, Kiel, Germany).The research team used GPS and accelerometer data loggers deployed on cheetahs, along with traditional observation methods. The study was funded by a Royal Society International Joint Project grant, a NERC New Investigator award and the Lewis Foundation.Explaining the team’s findings, lead researcher Dr Michael Scantlebury, from the School of Biological Sciences at Queen’s University Belfast, said: “The more we understand, about the physiology and the hunting tactics of this charismatic animal, the more we are able to ensure its continuing existence.””Our study found that whilst cheetahs are capable of running at exceptionally high speeds, the common adage that they simply ‘outrun’ their prey does not explain how they are able to capture more agile animals. Previous research has highlighted their incredible speed and acceleration and their ability to turn after escaping prey. We have now shown that hunt tactics are prey-specific.”In other words, we now know that rather than a simple maximum speed chase, cheetahs first accelerate towards their quarry before slowing down to mirror prey-specific escaping tactics. We suggest that cheetahs modulate their hunting speed to enable rapid turns, in a predator-prey arms race, where pace is pitted against agility. Basically, cheetahs have clear different chase strategies depending on prey species.”The research suggests that cheetah chases comprise two primary phases, the first an initial rapid acceleration resulting in high speed to quickly catch up with prey, followed by a second, which is a prey-specific slowing period, five to eight seconds before the end of the chase, that enables the cheetah to match turns instigated by prey as the distance between them closes.Dr Scantlebury added: “We have discovered that cheetahs first accelerate rapidly to get them close to the prey but then have to actively slow down to be able to match prey escape manoeuvres. It is like a deadly tango between the hunter and the hunted, with one mirroring the escape tactics of the other.””The time spent in the initial and second phase differs according to prey species, with some species such as ostriches, hares and steenbok attempting to escape by executing sudden changes in direction, whilst other species such as wildebeest, gemsbok and springbok attempt to run fast in a more or less straight line. It almost seems as if the amount of power or effort put into a chase is decided at the beginning of the chase depending on the prey species.”Dr Gus Mills, from the Lewis Foundation, South Africa and Oxford University’s WildCRU said: “Modern technology has given us the opportunity to record and measure facets of animal behaviour we have never been able to do. However, too often this is used without the essential backup of simultaneously observing the animals in the wild to validate what is being measured. …

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Spread of crop pests threatens global food security as Earth warms

Sep. 1, 2013 — A new study has revealed that global warming is resulting in the spread of crop pests towards the North and South Poles at a rate of nearly 3 km a year.The study, published in the journal Nature Climate Change and carried out by researchers at the University of Exeter and the University of Oxford, shows a strong relationship between increased global temperatures over the past 50 years and expansion in the range of crop pests.Currently 10-16% of global crop production is lost to pests. Crop pests include fungi, bacteria, viruses, insects, nematodes, viroids and oomycetes. The diversity of crop pests continues to expand and new strains are continually evolving. Losses of major crops to fungi, and fungi-like microorganisms, amount to enough to feed nearly nine percent of today’s global population. The study suggests that these figures will increase further if global temperatures continue to rise as predicted.The spread of pests is caused by both human activities and natural processes but is thought to be primarily the result of international freight transportation. The study suggests that the warming climate is allowing pests to become established in previously unsuitable regions. For example, warming generally stimulates insect herbivory at higher latitudes as seen in outbreaks of the Mountain pine beetle (Dendroctonus ponderosae) that has destroyed large areas of pine forest in the US Pacific Northwest. In addition, the rice blast fungus which is present in over 80 countries, and has a dramatic effect both on the agricultural economy and ecosystem health, has now moved to wheat. Considered a new disease, wheat blast is sharply reducing wheat yields in Brazil.Dr Dan Bebber from the University of Exeter said: “If crop pests continue to march polewards as Earth warms the combined effects of a growing world population and the increased loss of crops to pests will pose a serious threat to global food security.”Professor Sarah Gurr from the University of Exeter (previously at the University of Oxford) said: “Renewed efforts are required to monitor the spread of crop pests and to control their movement from region to region if we are to halt the relentless destruction of crops across the world in the face of climate change.”The study used published observations of the distribution of 612 crop pests collected over the past 50 years. …

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Why the body clock is slow to adjust to time changes

Aug. 29, 2013 — New research in mice reveals why the body is so slow to recover from jet-lag and identifies a target for the development of drugs that could help us to adjust faster to changes in time zone.With funding from the Wellcome Trust and F. Hoffmann La Roche, researchers at the University of Oxford, University of Notre Dame and F. Hoffmann La Roche have identified a mechanism that limits the ability of the body clock to adjust to changes in patterns of light and dark. And the team show that if you block the activity of this gene in mice, they recover faster from disturbances in their daily light/dark cycle that were designed to simulate jet-lag.Nearly all life on Earth has an internal circadian body clock that keeps us ticking on a 24-hour cycle, synchronising a variety of bodily functions such as sleeping and eating with the cycle of light and dark in a solar day. When we travel to a different time zone our body clock eventually adjusts to the local time. However this can take up to one day for every hour the clock is shifted, resulting in several days of fatigue and discombobulation.In mammals, the circadian clock is controlled by an area of the brain called the suprachiasmatic nuclei (SCN) which pulls every cell in the body into the same biological rhythm. It receives information from a specialised system in the eyes, separate from the mechanisms we use to ‘see’, which senses the time of day by detecting environmental light, synchronising the clock to local time. Until now, little was known about the molecular mechanisms of how light affects activity in the SCN to ‘tune’ the clock and why it takes so long to adjust when the light cycle changes.To investigate this, the Oxford University team led by Dr Stuart Peirson and Professor Russell Foster, used mice to examine the patterns of gene expression in the SCN following a pulse of light during the hours of darkness. They identified around 100 genes that were switched on in response to light, revealing a sequence of events that act to retune the circadian clock. …

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Learning a new language alters brain development

Aug. 29, 2013 — The age at which children learn a second language can have a significant bearing on the structure of their adult brain, according to a new joint study by the Montreal Neurological Institute and Hospital — The Neuro at McGill University and Oxford University. The majority of people in the world learn to speak more than one language during their lifetime. Many do so with great proficiency particularly if the languages are learned simultaneously or from early in development.Share This:The study concludes that the pattern of brain development is similar if you learn one or two language from birth. However, learning a second language later on in childhood after gaining proficiency in the first (native) language does in fact modify the brain’s structure, specifically the brain’s inferior frontal cortex. The left inferior frontal cortex became thicker and the right inferior frontal cortex became thinner. The cortex is a multi-layered mass of neurons that plays a major role in cognitive functions such as thought, language, consciousness and memory.The study suggests that the task of acquiring a second language after infancy stimulates new neural growth and connections among neurons in ways seen in acquiring complex motor skills such as juggling. The study’s authors speculate that the difficulty that some people have in learning a second language later in life could be explained at the structural level.”The later in childhood that the second language is acquired, the greater are the changes in the inferior frontal cortex,” said Dr. Denise Klein, researcher in The Neuro’s Cognitive Neuroscience Unit and a lead author on the paper published in the journal Brain and Language. “Our results provide structural evidence that age of acquisition is crucial in laying down the structure for language learning.”Using a software program developed at The Neuro, the study examined MRI scans of 66 bilingual and 22 monolingual men and women living in Montreal. …

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Shortening tails gave early birds a leg up

Aug. 13, 2013 — A radical shortening of their bony tails over 100 million years ago enabled the earliest birds to develop versatile legs that gave them an evolutionary edge, a new study shows.A team led by Oxford University scientists examined fossils of the earliest birds from the Cretaceous Period, 145-66 million years ago, when early birds, such as Confuciusornis, Eoenantiornis, and Hongshanornis, lived alongside their dinosaur kin. At this point birds had already evolved powered flight, necessitating changes to their forelimbs, and the team investigated how this new lifestyle related to changes in their hind limbs (legs).The team made detailed measurements of early bird fossils from all over the world including China, North America, and South America. An analysis of this data showed that the loss of their long bony tails, which occurred after flight had evolved, led to an explosion of diversity in the hind limbs of early birds, prefiguring the amazing variety of talons, stilts, and other specialised hind limbs that have helped to make modern birds so successful.A report of the research is published this week in Proceedings of the Royal Society B.’These early birds were not as sophisticated as the birds we know today — if modern birds have evolved to be like stealth bombers then these were more like biplanes,’ said Dr Roger Benson of Oxford University’s Department of Earth Sciences, who led the research. ‘Yet what surprised us was that despite some still having primitive traits, such as teeth, these early birds display an incredibly diverse array of versatile legs.’By comparing measurements of the main parts of the legs of early birds — upper leg, shin, and foot — to those of their dinosaur relatives Dr Benson and co-author Dr Jonah Choiniere of the University of the Witwatersrand, South Africa, were able to determine whether bird leg evolution was exceptional compared to leg evolution in dinosaurs.’Our work shows that, whilst they may have started off as just another type of dinosaur, birds quickly made a rather special evolutionary breakthrough that gave them abilities and advantages that their dinosaur cousins didn’t have,’ said Dr Rogers. ‘Key to this special ‘birdness’ was losing the long bony dinosaur tail — as soon as this happened it freed up their legs to evolve to become highly versatile and adaptable tools that opened up new ecological niches.’It was developing these highly versatile legs, rather than powered flight, that saw the evolutionary diversification of early birds proceed faster than was generally true of other dinosaurs.

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Extinctions of large animals sever the Earth’s ‘nutrient arteries’

Aug. 13, 2013 — A new study has demonstrated that large animals have acted as carriers of key nutrients to plants and animals over thousands of years and on continental scales.The paper in the advance online publication of the journal Nature Geoscience explains that vital nutrients are contained in the dung and bodies of big animals. As they eat and move more than small animals, they have a particularly important role in transporting nutrients into areas where the soil is otherwise infertile.In the study, the researchers use a new mathematical model to calculate the effect of mass extinctions of big animals around 12,000 years ago, focusing on a case study of the Amazon forest. They estimate that extinctions back then reduced the dispersal of phosphorus in the Amazon by 98%, with far-reaching environmental consequences that remain to this day. The model also enables them to forecast the likely environmental effects of the extinction of large animals currently under threat in Africa and Asian forests.Up until 12,000 years ago, much of the world looked like an African savannah. For instance, South America was teeming with large animals, described by scientists as ‘megafauna’ — a term for animals with a body mass of more than 44kg (the size of a large dog). These megafauna in South America, which overlapped with the earliest humans, included several species of elephant-like creatures, giant ground sloths, and armadillo-like creatures the size of a small car. In South America, most nutrients originate in the Andes mountain range and are washed into the forests through the river system. However, on dry land, these nutrients are in short supply unless they are transported through animal dung and bodies. While small animals distribute nutrients over small distances, large animals have a much greater range. …

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Under leaden skies: Where heavy metal clouds the stars

Aug. 1, 2013 — In a paper shortly to be published in the Oxford University Press journal Monthly Notices of the Royal Astronomical Society, a team of astronomers from the Armagh Observatory in Northern Ireland report the discovery of two unusual stars with extremely high concentrations of lead in their atmospheres.Naslim Neelamkodan, Simon Jeffery, Natalie Behara and Alan Hibbert are studying the surfaces of small hot stars, known as helium-rich subdwarfs. They are already known to be peculiar because they contain much less hydrogen and much more helium than normal.Three years ago they discovered one with a very high surface concentration of zirconium — better known for making false diamonds. Now studying a group of similar stars, they have discovered two which have surfaces containing ten thousand (10,000) times more lead than is present on the surface of the Sun.The discoveries were made in two stars, known as HE 2359-2844, 800 light years distant in the direction of the constellation of Sculptor and HE 1256-2738, located 1000 light years away in the constellation of Hydra. The astronomers studied the stars using observations from the archives of the European Southern Observatory’s Very Large Telescope in Chile. The light signatures, or spectra, of both stars showed a few features which did not match any atoms expected to be present. After some detective work, the team realised that the features were due to lead.With atomic number 82, lead is one of the heaviest naturally occurring elements; in the Sun there is less than one lead atom for every ten billion hydrogen atoms. At around 38000 degrees Celsius, the surfaces of HE 2359-2844 and HE 1256-2738 are so hot that three electrons are removed from every lead atom. The resulting ions produce distinctive lines in the star’s spectrum, from which the concentration of lead in the atmosphere can be measured. Using the same technique, HE 2359-2844 was also found to show ten thousand times more yttrium and zirconium than on the Sun. …

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Capturing black hole spin could further understanding of galaxy growth

July 29, 2013 — Astronomers have found a new way of measuring the spin in supermassive black holes, which could lead to better understanding about how they drive the growth of galaxies. The scientists at Durham University in the UK publish their work in a paper in the Oxford University Press journal Monthly Notices of the Royal Astronomical Society.The team of astronomers observed a black hole — with a mass 10 million times that of our Sun — at the centre of a spiral galaxy 500 million light years from Earth while it was feeding on the surrounding disc of material that fuels its growth and powers its activity.By viewing optical, ultra-violet and soft x-rays generated by heat as the black hole fed, they were able to measure how far the disc was from the black hole.This distance depends on black hole spin as a fast spinning black hole pulls the disc in closer to itself, the researchers said. Using the distance between the black hole and the disc, the scientists were able to estimate the spin of the black hole.The scientists said that understanding spin could lead to greater understanding of galaxy growth over billions of years.Black holes lie at the centres of almost all galaxies, and can spit out incredibly hot particles at high energies that prevent intergalactic gases from cooling and forming new stars in the outer galaxy. Scientists don’t yet understand why the jets are ejected into space, but the Durham experts believe that their power could be linked to the spin of the black hole. This spin is difficult to measure as it only affects the behaviour of material really close to the black hole.Lead researcher Professor Chris Done, in the Department of Physics, at Durham University, said: “We know the black hole in the centre of each galaxy is linked to the galaxy as a whole, which is strange because black holes are tiny in relation to the size of a galaxy. This would be like something the size of a large boulder (10m), influencing something the size of Earth.”Understanding this connection between stars in a galaxy and the growth of a black hole, and vice-versa, is the key to understanding how galaxies form throughout cosmic time.”If a black hole is spinning it drags space and time with it and that drags the accretion disc, containing the black hole’s food, closer towards it. This makes the black hole spin faster, a bit like an ice skater doing a pirouette.”By being able to measure the distance between the black hole and the accretion disc, we believe we can more effectively measure the spin of black holes.”Because of this, we hope to be able to understand more about the link between black holes and their galaxies.”The Durham scientists were able to measure the spin of the black hole using soft x-ray, optical and ultra-violet images captured by the European Space Agency’s XMM-Newton satellite.

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Discussing violence acts as ‘a stronger bond than blood ties’ for gang members

July 26, 2013 — Gang members trust one another more than their own family members if they have shared incriminating information about a violent act they are planning, says a new Oxford University study. Researchers analysed phone conversations between gangs wiretapped by the police in the 1990s. They found that the more contact two members had over the phone, the higher the level of cooperation they had on future tasks. The findings are published in the journal Rationality and Society.The researchers set out to examine the mechanisms by which criminal gangs build up trust amongst their members. Gang members cannot resolve their differences through the police or the courts should someone renege on their part of the deal. Recruiting family members is one way of creating greater cooperation between law-breakers. However, this study reveals that sharing information about violence creates an even stronger bond between two members, increasing cooperation on further tasks, both violent and non-violent.The researchers were given permission to analyse evidence prepared for historic court cases involving two Mafia gangs that had been based in Italy in the 1990s. An Italian gang operating near Naples and a Russian gang in Rome had been under surveillance for some time, unaware that the telephone conversations of key players were being tapped by the police. Transcripts were made of 1,400 contacts made by seven individuals in the Italian gang over seven months, while in the Russian Mafia case there was a total of 295 contacts between 19 people over nine months.The Oxford researchers coded the information contained in the transcripts, tracking which individuals within the gang were in contact with each other and monitoring how often they were in touch with one another. They also coded the content of the conversations between two gang members. …

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Fossil shows fish had sucker on its back

July 26, 2013 — A 30 million year-old fossil has revealed how remoras — also called sharksuckers — evolved the sucker that enables them to stick to other fishes and ‘hitch a ride’.Previous evidence, such as the segmented structure of the sucker and how it develops in a similar way to fins in normal fish, led scientists to believe that it must be a modified dorsal fin — the fin located on the back of normal fishes. But the evolutionary steps that led from fin to sucker were a mystery.Now a team led by scientists from Oxford University and London’s Natural History Museum has studied an early fossil remora and found that it evolved a fully-functioning sucker — ‘adhesion disc’ — on its back. It was only later in the evolutionary history of remoras that the sucker migrated to the top of the head where it is found in all remoras alive today.A report of the research is published in the journal Proceedings of the Royal Society B.’The remora sucker is a truly amazing anatomical specialisation but, strange as it may seem, it evolved from a spiny fin,’ said Dr Matt Friedman of Oxford University’s Department of Earth Sciences, lead author of the report. ‘In this fossil the fin is clearly modified as a disc but is found on the back of the fish. It enables us to say that first fin spines on the back broadened to form wide segments of a suction disc. After the disc evolved, it migrated to the skull, and it was there that individual segments became divided in two, the number of segments increased, and a row of spines were developed on the back of individual segments.’Modern remoras use their sucker to fasten themselves to hosts including whales, turtles, and sharks. The researchers have shown that the fossil remora (†Opisthomyzon), dating from the Oligocene period and unearthed in Switzerland, falls outside the branch on the evolutionary tree occupied by all living remoras. As such it preserves primitive aspects of the shape and construction of the adhesion disc not found in modern remoras, all of which share discs that are broadly similar in construction.’It’s exciting that fossil fish from the Natural History Museum were so crucial to this study, and shows the important value of our collections for scientific research,’ said Dr Zerina Johanson, palaeontologist at London’s Natural History Museum. ‘Following painstaking preparation by our fossil preparator, Mark Graham, we were able to clearly see several important features of the disc in the fossil, for example that it’s much shorter than the disc in living remoras, with fewer segments.”One of the remarkable things we’ve learned about modern fishes is that some creatures that look very different, for example pufferfishes and anglerfishes, are actually very closely related,’ said Dr Friedman. ‘It’s through fossils like this one, which preserve body plans and structures that have been pruned from the evolutionary tree by extinction, that we can unravel how they diverged from one another to assume the very different forms we see today.’

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Brain research shows psychopathic criminals do not lack empathy, but fail to use it automatically

July 24, 2013 — Criminal psychopathy can be both repulsive and fascinating, as illustrated by the vast number of books and movies inspired by this topic. Offenders diagnosed with psychopathy pose a significant threat to society, because they are more likely to harm other individuals and to do so again after being released. A brain imaging study in the Netherlands shows individuals with psychopathy have reduced empathy while witnessing the pains of others. When asked to empathize, however, they can activate their empathy. This could explain why psychopathic individuals can be callous and socially cunning at the same time.Why are psychopathic individuals more likely to hurt others? Individuals with psychopathy characteristically demonstrate reduced empathy with the feelings of others, which may explain why it is easier for them to hurt other people. However, what causes this lack of empathy is poorly understood. Scientific studies on psychopathic subjects are notoriously hard to conduct. “Convicted criminals with a diagnosis of psychopathy are confined to high-security forensic institutions in which state-of-the-art technology to study their brain, like magnetic resonance imaging, is usually unavailable,” explains Professor Christian Keysers, Head of the Social Brain Lab in Amsterdam, and senior author of a study on psychopathy appearing in the journal Brain this week. “Bringing them to scientific research centres, on the other hand, requires the kind of high-security transportation that most judicial systems are unwilling to finance.”The Dutch judicial system, however, seems to be an exception. …

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Mental illness linked to early death in people with epilepsy

July 22, 2013 — People with epilepsy are ten times more likely to die early, before their mid-fifties, compared with the general population, according to a 41 year study in Sweden published today in the Lancet and part-funded by the Wellcome Trust.The findings reveal a striking correlation between premature death and mental illness in these patients and people with epilepsy were four times more likely to have received a psychiatric diagnosis in their lifetime compared with the general population.The figures are considerably higher than previously thought and have important implications for epilepsy management.Researchers at the University of Oxford and Karolinska Institutet studied 69,995 people with epilepsy born in Sweden between 1954 and 2009 and followed up over 41 years, between 1969 and 2009. They compared mortality and cause of death information from these patients with 660,869 age- and sex-matched people from the general population. The study also looked at the unaffected siblings of those with epilepsy, in order to rule out the influence of background factors such as genetic risk factors and upbringing.Throughout the course of the study, almost nine per cent (6,155) of people with epilepsy died compared with less than one per cent (4,892) of people from the general population.The most important cause of death in people with epilepsy that was not clearly related to the underlying disease process was death by external causes, such as accident or suicide, accounting for almost 16 per cent of deaths. Three quarters of these deaths were amongst patients who also had a psychiatric diagnosis.Although suicide and deaths from accidents were still relatively rare, the odds of a person with epilepsy committing suicide during the study were four times higher than the general population and there was a strong correlation with mental illness and substance abuse.Dr Seena Fazel, a Wellcome Trust Senior Clinical Research Fellow at the University of Oxford and main author of the study, said: “This is the largest report to date to look at psychiatric associations in epilepsy and their contribution to premature mortality. Our finding that three quarters of suicide and accident deaths in epilepsy also had a diagnosis of mental illness strongly identifies this as a high risk population to focus preventative strategies and more intensive treatment.”Improving the identification, monitoring and treatment of psychiatric problems in epilepsy patients could make an important contribution to reducing the risk of premature death that we’re currently seeing in these patients.”The study also reveals that the odds of dying in a non-vehicle accident, such as drug poisoning or drowning, were more than five times higher for people with epilepsy than control populations.”Our findings also highlight general accidents as a major, preventable cause of death in epilepsy patients and suggest that specific warnings, in addition to those already given around driving, should be provided to patients at the time of diagnosis to ensure they are aware of the risks,” added Dr Fazel.Professor Charles Newton from the Wellcome Trust programme at the Kenyan Medical Research Institute (KEMRI) and the Department of Psychiatry at Oxford University, said: “Although it is well -recognised that psychiatric and addiction disorders occur in epilepsy, in high income (Western) countries, epilepsy is often managed by neurologists only. The findings from this study would suggest that clinical epilepsy services should review their liaison with psychiatric and addiction services as a priority.”This is the first study to look at the odds of premature death in people with epilepsy compared with their unaffected siblings, revealing that they do not differ significantly from odds of death in epilepsy compared with general population controls. This provides further weight to the evidence that epilepsy as a disease is an independent risk factor for death by any cause.

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Cheaper anti-cancer drug as effective as expensive drug in treating most common cause of blindness in older adults

July 19, 2013 — An anti-cancer drug has been proven to be equally as effective in treating the most common cause of blindness in older adults as a more expensive drug specifically formulated for this purpose.The results of a two-year trial, led by Queen’s scientist Professor Usha Chakravarthy, and published in The Lancet today (Friday 19 July), show that two drug treatments Lucentis and Avastin are equally effective in treating neovascular or wet age-related macular degeneration (wet AMD).Wet AMD is a common cause of sight loss in older people with at least 23,000 older people diagnosed with the condition in the UK each year. Without treatment two thirds of people with this condition will experience severe loss of sight within two years of being diagnosed.Lucentis, the drug most commonly used in the UK at present to treat wet AMD, costs about £700 per injection and Avastin costs about £60 per injection. The NHS could save £84.5 million annually based on injecting 17,295 eyes each year by switching from Lucentis to Avastin. Avastin is already used to treat wet AMD in some parts of the UK and extensively elsewhere in the world and also for other eye conditions.Over the past five years, a team of scientists and eye specialists from 23 hospitals and UK universities, including Queen’s University Belfast, University of Bristol, University of Liverpool, University of Southampton and University of Oxford, have investigated whether Lucentis and Avastin and the way they are given are equally effective and safe.610 people with wet AMD entered a two-year trial known as IVAN which is one of the largest ever carried out in the field of eye disease in the UK. Patients received injections of the drug into the affected eye every month for the first three months. Patients were then subdivided to receive the injections at every visit (monthly group) or only if the specialist decided there was persistent disease activity (as needed group).The IVAN study’s two year results show that sight was equally well preserved with either of the two drugs. Giving the treatment regularly every month, resulted in slightly better levels of sight which was detected through testing of near visual acuity and contrast sensitivity. The ‘as needed’ group received on average 13 injections over the two year period compared to 23 for the monthly treatment group. However, continuous treatment caused a higher proportion of eyes to develop a condition known as geographic atrophy which is a thinning of the retina and its blood supply.Professor Usha Chakravarthy of Queen’s University Belfast’s Centre for Vision and Vascular Science, who led the research study team said: “The IVAN results at the end of year two show that Lucentis and Avastin have similar functional effectiveness regardless of the drug received. With respect to monthly versus as needed treatment, while there was marginally better eyesight in the former, the development of atrophy is a matter of concern in the longer term.”The IVAN study was funded by the National Institute for Health Research Health Technology Assessment (NIHR HTA) programme. …

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Study helps understand how nature maintains diversity

July 9, 2013 — By studying rapidly evolving bacteria as they diversify and compete under varying environmental conditions, researchers have shown that temporal niches are important to maintaining biodiversity in natural systems. The research is believed to be the first experimental demonstration of temporal niche dynamics promoting biodiversity over evolutionary time scales.The temporal niches — changes in environmental conditions that occur during specific periods of time — promoted frequency-dependent selection within the bacterial communities and positive growth of new mutants. They played a vital role in allowing diversity among bacterial phenotypes to persist.The research provides new insights into the factors that promote species coexistence and diversity in natural systems. Understanding the mechanisms governing the origin and maintenance of biodiversity is important to scientists studying the roles of both ecology and evolution in natural systems.”This study provides the first experimental evidence showing the impact of temporal niche dynamics on biodiversity evolution,” said Lin Jiang, co-author of the paper and an associate professor in the School of Biology at the Georgia Institute of Technology. “Our laboratory results in bacteria can potentially explain the diversity dynamics that have been observed for other organisms over evolutionary time.”The research, which was supported by the National Science Foundation, was scheduled to be published July 9 in the journal Nature Communications.In experimental manipulation of the bacterium Pseudomonas fluorescens, the researchers showed that alternating environmental conditions in 24-hour cycles strongly influences biodiversity dynamics by helping to maintain closely-related phenotypes that might otherwise be lost to competition with a dominant phenotype. The experiment followed the bacteria through more than 200 generations over a period of nearly two weeks.In the laboratory, Jiang and graduate student Jiaqi Tan established communities of the bacterium in test tubes called microcosms. In designing the experiments, they collaborated with Colleen Kelly, a senior research associate in the Department of Zoology at the University of Oxford.”You begin with one phenotype, and within two days, you might have two or three different phenotypes,” said Jiang. “The system can do this in a matter of days.”Through a 12-day experimental period, the researchers subjected one group of cultures to 24-hour periods in which they were alternately allowed to grow undisturbed and shaken vigorously. To control for the impact of starting conditions, cultures within those two groups were chosen to begin with a period of static growth, while others began with a period of shaken growth. Finally, groups of control cultures were grown under continuous shaking or continuous static conditions.During the study, the researchers periodically measured the population sizes of each phenotype present in each culture. …

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Cockatoos ‘pick’ puzzle box locks: Cockatoos show technical intelligence on a five-lock problem

July 4, 2013 — A species of Indonesian parrot can solve complex mechanical problems that involve undoing a series of locks one after another, revealing new depths to physical intelligence in birds.A team of scientists from Oxford University, the University of Vienna, and the Max Planck Institute, report in PLOS ONE a study in which ten untrained Goffin’s cockatoos [Cacatua goffini] faced a puzzle box showing food (a nut) behind a transparent door secured by a series of five different interlocking devices, each one jamming the next along in the series.To retrieve the nut the birds had to first remove a pin, then a screw, then a bolt, then turn a wheel 90 degrees, and then shift a latch sideways. One bird, called ‘Pipin’, cracked the problem unassisted in less than two hours, and several others did it after being helped either by being presented with the series of locks incrementally or being allowed to watch a skilled partner doing it.Watch a video of cockatoos solving the puzzle box: http://www.zoo.ox.ac.uk/group/kacelnik/lb_movie_s1.movThe scientists were interested in the birds’ progress towards the solution, and on what they knew once they had solved the full task.The team found that the birds worked determinedly to sort one obstacle after another even though they were only rewarded with the nut once they had solved all five devices. The scientists suggest that the birds seemed to progress as if they employed a ‘cognitive ratchet’ process: once they discovered how to solve one lock they rarely had any difficulties with the same device again. This, the scientists argue, is consistent with the birds having a representation of the goal they were after.After the cockatoos mastered the entire sequence the scientists investigated whether the birds had learnt how to repeat a sequence of actions or instead responded to the effect of each lock.Dr Alice Auersperg, who led the study at the Goffin Laboratory at Vienna University, said: ‘After they had solved the initial problem, we confronted six subjects with so-called ‘Transfer tasks’ in which some locks were re-ordered, removed, or made non-functional. Statistical analysis showed that they reacted to the changes with immediate sensitivity to the novel situation.’Professor Alex Kacelnik of Oxford University’s Department of Zoology, a co-author of the study, said: ‘We cannot prove that the birds understand the physical structure of the problem as an adult human would, but we can infer from their behaviour that they are sensitive to how objects act on each other, and that they can learn to progress towards a distant goal without being rewarded step-by-step.’Dr Auguste von Bayern, another co-author from Oxford University said: ‘The birds’ sudden and often errorless improvement and response to changes indicates pronounced behavioural plasticity and practical memory. We believe that they are aided by species characteristics such as intense curiosity, tactile exploration techniques and persistence: cockatoos explore surrounding objects with their bill, tongue and feet. A purely visual explorer may have never detected that they could move the locks.’Professor Kacelnik said: ‘It would be too easy to say that the cockatoos understand the problem, but this claim will only be justified when we can reproduce the details of the animals’ response to a large battery of novel physical problems.’

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Alzheimer’s disease protein controls movement in mice

June 21, 2013 — Researchers in Berlin and Munich, Germany and Oxford, United Kingdom, have revealed that a protein well known for its role in Alzheimer’s disease controls spindle development in muscle and leads to impaired movement in mice when the protein is absent or treated with inhibitors. The results, which are published in The EMBO Journal, suggest that drugs under development to target the beta-secretase-1 protein, which may be potential treatments for Alzheimer’s disease, might produce unwanted side effects related to defective movement.Share This:Alzheimer’s disease is the most common form of dementia found in older adults. The World Health Organization estimates that approximately 18 million people worldwide have Alzheimer’s disease. The number of people affected by the disease may increase to 34 million by 2025. Scientists know that the protein beta-secretase-1 or Bace1, a protease enzyme that breaks down proteins into smaller molecules, is involved in Alzheimer’s disease. Bace1 cleaves the amyloid precursor protein and generates the damaging Abeta peptides that accumulate as plaques in the brain leading to disease. Now scientists have revealed in more detail how Bace1 works.”Our results show that mice that lack Bace1 proteins or are treated with inhibitors of the enzyme have difficulties in coordination and walking and also show reduced muscle strength,” remarked Carmen Birchmeier, one of the authors of the paper, Professor at the Max-Delbrück-Center for Molecular Medicine in Berlin, Germany, and an EMBO Member. “In addition, we were able to show that the combined activities of Bace1 and another protein, neuregulin-1 or Nrg1, are needed to sustain the muscle spindles in mice and to maintain motor coordination.”Muscle spindles are sensory organs that are found throughout the muscles of vertebrates. They are able to detect how muscles stretch and convey the perception of body position to the brain. The researchers used genetic analyses, biochemical studies and interference with pharmacological inhibitors to investigate how Bace1 works in mice. …

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