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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When mothers are active so are their children — but many mothers are not

Parents are strong influences in the lives of young children, with patterns of behaviour established in the early years laying the foundation for future choices. A new study suggests that, when it comes to levels of physical activity, it is mothers who set (or don’t set) the pace.An analysis of the physical activity levels of more than 500 mothers and pre-schoolers, assessed using activity monitors to produce accurate data, found that the amount of activity that a mother and her child did each day was closely related. Overall, maternal activity levels were strikingly low: only 53% of mothers engaged in 30 minutes of moderate-to-vigorous physical activity at least once a week. The UK Government recommends achieving 150 minutes of at least ‘moderate intensity physical activity’ (such as brisk walking) over the week as one of the ways of achieving its physical activity guidelines.The results of the study are published in the journal Pediatrics on 24 March 2014. The paper ‘Activity Levels in Mothers and Their Preschool Children’ suggests that, given the link between mothers and young children, policies to improve children’s health should be directed to whole families and seek to engage mothers in particular.The research was overseen by Dr Esther van Sluijs at the MRC Epidemiology Unit and the Centre for Diet and Activity Research, University of Cambridge, and led by Kathryn Hesketh (formerly of Cambridge and now UCL), in collaboration with researchers at the MRC Lifecourse Epidemiology Unit, University of Southampton.The study is the first to show a direct association in a large sample of mothers and children, both fitted with activity monitors at the same time. It shows that young children are not ‘just naturally active’ and that parents have an important role to play in the development of healthy activity habits early on in life. The research also provides important evidence for policy makers to inform programmes that promote physical activity in families with young children. Its findings suggest that all family members can benefit from such efforts.It is well established that physical activity is closely linked to health and disease prevention. Research shows that active mothers appear to have active school-aged children, who are in turn more likely than their less active peers to have good health outcomes. However, there has been little large-scale research into the association between the activity of mothers and that of preschool-aged children or about the demographic and temporal factors that influence activity levels in mothers of young children.The research published in the Pediatrics paper drew on data obtained from 554 women and their four-year-old children who are participants in the Southampton Women’s Survey, devised and run by the MRC Lifecourse Epidemiology Unit. …

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Higher exposure to take-out food could double the odds of being obese

People exposed to takeaway food outlets around their home, at work and on their way to work are more likely to consume more of these foods, as well as being more likely to be obese, suggest a paper published on bmj.com today.During the past decade in the UK, consumption of food away from home has risen by 29% while the number of takeaways has increased dramatically. This, the researchers say, could be contributing to rising levels of overweight and obesity.Despite increasing policy focus, identifying the association between exposures to unhealthy neighborhood food outlets, diet and body weight has proved challenging.Researchers from the University of Cambridge looked to examine the extent to which exposure to takeaway food outlets in home and non-home environments was associated with eating takeaway foods, BMI and likelihood of being overweight or obese.They used data from the Fenland Study — a population based cohort study of adults aged 29-62 in 2011, in Cambridgeshire, UK, conducted by the MRC Epidemiology Unit. Data on 10,452 participants were available, with 5,442 participants eligible for their study. Only adults working outside the home were included.In addition to food outlets within home and work ‘neighborhoods’, the study also accounted for takeaways around commuting routes between home and work. Commuting routes were modeled according to mode of travel using the shortest distance along the street network between home and work addresses.Analyses allowed for a wide range of factors known to be associated with risk of obesity: age, sex, total household income, highest educational qualification, car ownership, total energy intake, smoking status and physical activity energy expenditure. Physical activity was objectively assessed in the Fenland Study using combined heart rate sensors and accelerometers wearable devices to measure body movement).Using data from food frequency questionnaires, the researchers estimated grams of daily intake of pizza, burgers, fried food (for example fried chicken) and chips, as a marker of takeaway food consumption.As a second outcome, the researchers looked at average body mass index, which they calculated from measured height and weight, and odds of being overweight and obese, based on World Health Organization definitions.Results showed that individuals were exposed to 48% more takeaway outlets at work than at home. The average exposure combining home and work neighborhoods and commuting routes was 32 outlets.Among domains at home, at work, and along commuting routes, associations between takeaway exposure and diet were strongest in work environments, with evidence of a dose-response relationship. Combining the three domains (work, home and commute) there was evidence of a positive and significant dose-response relationship between takeaway outlet exposure and takeaway food consumption. The most exposed group of people consumed an additional 5.7 grams per day compared with the least exposed group.Associations between BMI and exposure to takeaway food outlets were equally consistent. The group most exposed to takeaway food outlets in all environments combined were estimated to have a BMI 1.21 greater than those least exposed, with evidence of a dose-response effect. …

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Human brains ‘hard-wired’ to link what we see with what we do

Your brain’s ability to instantly link what you see with what you do is down to a dedicated information ‘highway’, suggests new UCL-led research.For the first time, researchers from UCL (University College London) and Cambridge University have found evidence of a specialized mechanism for spatial self-awareness that combines visual cues with body motion.Standard visual processing is prone to distractions, as it requires us to pay attention to objects of interest and filter out others. The new study has shown that our brains have separate ‘hard-wired’ systems to visually track our own bodies, even if we are not paying attention to them. In fact, the newly-discovered network triggers reactions even before the conscious brain has time to process them.The researchers discovered the new mechanism by testing 52 healthy adults in a series of three experiments. In all experiments, participants used robotic arms to control cursors on two-dimensional displays, where cursor motion was directly linked to hand movement. Their eyes were kept fixed on a mark at the centre of the screen, confirmed with eye tracking.In the first experiment, participants controlled two separate cursors with their left and right hands, both equally close to the centre. The goal was to guide each cursor to a corresponding target at the top of the screen. Occasionally the cursor or target on one side would jump left or right, requiring participants to take corrective action. Each jump was ‘cued’ with a flash on one side, but this was random so did not always correspond to the side about to change.Unsurprisingly, people reacted faster to target jumps when their attention was drawn to the ‘correct’ side by the cue. However, reactions to cursor jumps were fast regardless of cuing, suggesting that a separate mechanism independent of attention is responsible for tracking our own movements.”The first experiment showed us that we react very quickly to changes relating to objects directly under our own control, even when we are not paying attention to them,” explains Dr Alexandra Reichenbach of the UCL Institute of Cognitive Neuroscience, lead author of the study. “This provides strong evidence for a dedicated neural pathway linking motor control to visual information, independently of the standard visual systems that are dependent on attention.”The second experiment was similar to the first, but also introduced changes in brightness to demonstrate the attention effect on the visual perception system. …

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London’s bicycle sharing scheme has had positive overall health effect

London’s bicycle sharing scheme has had positive overall health effect, but benefits of cycling in central London are larger for men and older people. The authors say the potential benefits of cycling “may not currently apply to all groups in all settings.”Over 600 cities around the world have implemented bicycle sharing schemes, but there is very little published evidence on the health effects of such schemes.So researchers at the University of Cambridge, University College London and the London School of Hygiene and Tropical Medicine set out to estimate the health impacts of London’s cycle hire scheme on its users.Using registration and usage data collected from April 2011 to March 2012, they modeled the medium term health impacts of the scheme on male and female users of different ages, by estimating changes in physical activity, road traffic injury rates, and exposure to air pollution.The authors used a composite term to describe the impact of ill health and death, known as DALYs, or disability adjusted life years.From April 2011 to March 2012, 578,607 unique cycle hire users made a total of 7.4 million cycle hire trips and thereby generated 2.1 million hours of use.This equates to 12% of the estimated 61.2 million cycle trips made by adults each year that started or ended in the cycle hire zone, and 10% of the estimated 20.8 million hours of cycling duration.Results suggest that the scheme appears to have had a positive overall health effect, with these benefits reflecting reductions in diseases affected by physical inactivity.There was no evidence that cycling on a bicycle sharing scheme was more dangerous than own bicycle cycling; indeed, if anything there was a trend in the opposite direction, further boosting the benefits of the scheme to date. However because the London Cycle Hire scheme hasn’t been operating long enough to get a very precise estimate of the true injury rates on the scheme, the researchers also repeated their analyses using background injury rates for cycling in the hire zone (i.e. injury rates for all cycling, not specifically for cycle hire cycling).When using these background injury rates, the researchers found that the ratio of benefits to harms of cycling in central London vary markedly by age and sex.At older ages (45-59 years), the benefits of cycling were much larger than the harms. But in the youngest age group (15-29 years), the medium term benefits and harms of cycling in central London were both comparatively small and potentially negative.When the researchers analyzed the results by sex, they found smaller benefits among women, largely reflecting higher background fatal injury rates for female cyclists in central London. The authors stress that these results by age and sex relate to cycling in general in central London, not specifically to cycling on the hire bikes.”Our findings indicate that benefits of cycling in central London could be substantially increased both by increasing the share of trips made by older users and by reducing the risks of injury,” say the authors.They point to the Netherlands, where a comprehensive and well maintained system of cycle tracks, physically protected from fast motor traffic, “have helped to make cycling widespread at all ages and reduce the risks of injury.”Providing similar quality infrastructure in London “might help realize the substantial potential health benefits that cycling could offer at population level,” they conclude.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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Embryology: Scientists crack open ‘black box’ of development and see a ‘rosette’

We know much about how embryos develop, but one key stage — implantation — has remained a mystery. Now, scientists from Cambridge have discovered a way to study and film this ‘black box’ of development. Their results — which will lead to the rewriting of biology text books worldwide — are published in the journal Cell.Embryo development in mammals occurs in two phases. During the first phase, pre-implantation, the embryo is a small, free-floating ball of cells called a blastocyst. In the second, post-implantation, phase the blastocyst embeds itself in the mother’s uterus.While blastocysts can be grown and studied outside the body, the same has not been true from implantation. And because embryos are so closely connected to their mothers, implantation has also been difficult to study in the womb.According to study author Professor Magdalena Zernicka-Goetz of the University of Cambridge: “We know a lot about pre-implantation, but what happens after implantation — and particularly the moment of implantation — is an enigma.”Scientists are interested in studying implantation because the embryo undergoes huge changes in such a short space of time.”During these two days, it goes from a relatively simple ball to a much larger, more complex cup-like structure, but exactly how that happens was a mystery — a black box of development. That is why we needed to develop a method that would allow us to culture and study embryos during implantation,” she explained.Working with mouse cells, Professor Zernicka-Goetz and her colleague Dr Ivan Bedzhov succeeded in creating the right conditions outside the womb to study the implantation process.To be able to support development, they created a system comprising a gel and medium that, as well as having the right chemical and biological properties, was of similar elasticity to uterine tissue. Crucially, this gel was transparent to optical light, allowing then to film the embryo during implantation.This new method revealed that on its way from ball to cup, the blastocyst becomes a ‘rosette’ of wedge-shaped cells, a structure never before seen by scientists.”It’s a beautiful structure. This rosette is what a mouse looks like on the 4th day of its life, and most likely what we look like on the 7th day of ours, and it’s fascinating how beautiful we are then, and how these small cells organise so perfectly to allow us to develop.”As well as answering a fundamental question in developmental biology, the new method will allow scientists to study embryo growth and development at implantation for the first time, which could help improve the success of IVF, and extend our knowledge of stem cells, which could advance their use in regenerative medicine.The findings also mean developmental biology text books will need rewriting. “The text books make an educated guess of what happened during this part of development, but we now know that what I learned and what I teach my students about this was totally wrong,” said Professor Zernicka-Goetz.Story Source:The above story is based on materials provided by University of Cambridge. …

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Males and females differ in specific brain structures

Reviewing over 20 years of neuroscience research into sex differences in brain structure, a Cambridge University team has conducted the first meta-analysis of the evidence, published this week in the journal Neuroscience and Biobehavioral Reviews.The team, led by doctoral candidate Amber Ruigrok and Professors John Suckling and Simon Baron-Cohen in the Department of Psychiatry, performed a quantitative review of the brain imaging literature testing overall sex differences in total and regional brain volumes. They searched all articles published between 1990 and 2013. A total of 126 articles were included in the study, covering brains from individuals as young as birth to 80 years old.They found that males on average have larger total brain volumes than women (by 8-13%). On average, males had larger absolute volumes than females in the intracranial space (12%; >14,000 brains), total brain (11%; 2,523 brains), cerebrum (10%; 1,851 brains), grey matter (9%; 7,934 brains), white matter (13%; 7,515 brains), regions filled with cerebrospinal fluid (11.5%; 4,484 brains), and cerebellum (9%; 1,842 brains). Looking more closely, differences in volume between the sexes were located in several regions. These included parts of the limbic system, and the language system.Specifically, males on average had larger volumes and higher tissue densities in the left amygdala, hippocampus, insular cortex, putamen; higher densities in the right VI lobe of the cerebellum and in the left claustrum; and larger volumes in the bilateral anterior parahippocampal gyri, posterior cingulate gyri, precuneus, temporal poles, and cerebellum, areas in the left posterior and anterior cingulate gyri, and in the right amygdala, hippocampus, and putamen.By contrast, females on average had higher density in the left frontal pole, and larger volumes in the right frontal pole, inferior and middle frontal gyri, pars triangularis, planum temporale/parietal operculum, anterior cingulate gyrus, insular cortex, and Heschl’s gyrus; bilateral thalami and precuneus; the left parahippocampal gyrus, and lateral occipital cortex.The results highlight an asymmetric effect of sex on the developing brain. Amber Ruigrok, who carried out the study as part of her PhD, said: “For the first time we can look across the vast literature and confirm that brain size and structure are different in males and females. We should no longer ignore sex in neuroscience research, especially when investigating psychiatric conditions that are more prevalent in either males or females.”Professor Suckling added: “The sex differences in the limbic system include areas often implicated in psychiatric conditions with biased sex ratios such as autism, schizophrenia, and depression. This new study may therefore help us understand not just typical sex differences but also sex-linked psychiatric conditions. It is important to note that we only investigated sex differences in brain structure, so we cannot infer anything about how this relates to behaviour or brain function. …

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Study shows yogurt consumption reduces the risk of type 2 diabetes

New research published in Diabetologia (the journal of the European Association for the Study of Diabetes) shows that higher consumption of yoghurt, compared with no consumption, can reduce the risk of new-onset type 2 diabetes by 28%. Scientists at the University of Cambridge found that in fact higher consumption of low-fat fermented dairy products, which include all yoghurt varieties and some low-fat cheeses, also reduced the relative risk of diabetes by 24% overall.Lead scientist Dr Nita Forouhi, from the Medical Research Council (MRC) Epidemiology Unit at the University of Cambridge, commented “this research highlights that specific foods may have an important role in the prevention of type 2 diabetes and are relevant for public health messages.”Dairy products are an important source of high quality protein, vitamins and minerals. However, they are also a source of saturated fat, which dietary guidelines currently advise people not to consume in high quantities, instead recommending they replace these with lower fat options.Previous studies on links between dairy product consumption (high fat or low fat) and diabetes had inconclusive findings. Thus, the nature of the association between dairy product intake and type 2 diabetes remains unclear, prompting the authors to carry out this new investigation, using much more detailed assessment of dairy product consumption than was done in past research.The research was based on the large EPIC-Norfolk study which includes more than 25,000 men and women living in Norfolk, UK. It compared a detailed daily record of all the food and drink consumed over a week at the time of study entry among 753 people who developed new-onset type 2 diabetes over 11 years of follow-up with 3,502 randomly selected study participants. This allowed the researchers to examine the risk of diabetes in relation to the consumption of total dairy products and also types of individual dairy products.The consumption of total dairy, total high-fat dairy or total low-fat dairy was not associated with new-onset diabetes once important factors like healthier lifestyles, education, obesity levels, other eating habits and total calorie intake were taken into account. Total milk and cheese intakes were also not associated with diabetes risk. In contrast, those with the highest consumption of low-fat fermented dairy products (such as yoghurt, fromage frais and low-fat cottage cheese) were 24% less likely to develop type 2 diabetes over the 11 years, compared with non-consumers.When examined separately from the other low-fat fermented dairy products, yoghurt, which makes up more than 85% of these products, was associated with a 28% reduced risk of developing diabetes. This risk reduction was observed among individuals who consumed an average of four and a half standard 125g pots of yoghurt per week. The same applies to other low-fat fermented dairy products such as low-fat unripened cheeses including fromage frais and low-fat cottage cheese. …

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The eyes have it: Jackdaw birds use their eyes to communicate with each other

Researchers in Cambridge and Exeter have discovered that jackdaws use their eyes to communicate with each other — the first time this has been shown in non-primates.While what humans do with their eyes has been well studied, we know almost nothing about whether birds communicate with members of the same species with their eyes.The new study, published today in Biology Letters, shows that jackdaw eyes are used as a warning signal to successfully deter competitors from coming near their nest boxes.Gabrielle Davidson of the University of Cambridge, who led the study, said: “Jackdaw eyes are very unusual. Unlike their close relatives, the rooks and crows — which have very dark eyed — jackdaw eyes are almost white and their striking pale irises are very conspicuous against their dark feathers.”While most birds have black or dark brown eyes, bright eyes are not unknown in the avian world, and around 10% of passerines (perching birds) have coloured irises. The question Davidson wanted to answer was do jackdaws use their bright eyes to communicate with fellow jackdaws?Just before the spring breeding season arrived last year, Davidson installed one of four different pictures in 100 jackdaw nest boxes on the outskirts of Cambridge. The pictures were either black (the control), a pair of jackdaw eyes, a pair of jackdaw eyes in a jackdaw’s face, or a jackdaw’s face with a pair of black rook eyes. She then filmed the effect the different pictures had on the birds’ behaviour.”Jackdaws are unique among the crow family in that they nest in cavities in trees. These hollows are natural — the birds cannot excavate their own nest cavities as some woodpeckers do — so they have to compete for a limited resource. And because jackdaws nest in close proximity to each other, they fight a lot to gain the best nesting sites,” she explained. Often what initiates these fights are jackdaws approaching nest boxes that are not their own.After analysing 40 videos of jackdaws peeking into each other’s nest boxes, she found that compared with the other nest boxes, those that contained the picture of a jackdaw with its bright eyes was much more likely to deter the birds from landing on it, and that the birds spent less time near such a nest box.Davidson’s study is the first to show the eyes being used as a means of communication between members of the same species outside primates.”Before now we knew very little about why some birds have brightly coloured eyes. In jackdaws, the pale eyes may function to improve their ability to defend their nest and chicks from competitors. It also raises the question of whether this is unique to jackdaws, or if other cavity nesting birds also use their eyes in a similar way,” she added.Story Source:The above story is based on materials provided by University of Cambridge. …

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Feeling powerless increases the weight of the world… literally

New research shows that the more personally and socially powerless you feel the heavier objects appear to weigh.Scientists have found that people who feel powerless actually see the world differently, and find a task to be more physically challenging than those with a greater sense of personal and social power.Eun Hee Lee — a researcher working with Dr Simone Schnall at Cambridge’s Department of Psychology — carried out a series of tests in which volunteers were surreptitiously surveyed about their own social power, then asked to lift boxes of varying weights and guess how heavy they were. Those who felt powerless consistently perceived the weight of the boxes as much heavier than those who felt more powerful.The study is the first demonstration that power — a ‘psychosocial’ construct relating to the control of resources — changes peoples’ perception of objects; that how you feel about your social standing in a situation can influence how you see the physical environment.The researchers say this overestimation of weight may be an adaptive strategy when faced with a lack of resources: when in a position of powerlessness, it would be ‘advantageous’ to have an overly cautious approach to the world in order to preserve your existing limited resources.Experiencing perceptual attributes of the world — such as the weight of objects — in an “exaggerated fashion” when feeling powerless might be symptomatic of this instinctive resource conservation.The study is published this week in the Journal of Experimental Psychology.”Although many psychological studies have been conducted on power not much was known about how power influences actual perceptual experiences in everyday life,” said lead researcher Eun Hee Lee.”This research demonstrates that people’s social role, as indicated by a sense of social power, or a lack therefore, can change the way they see the physical environment.”To measure a person’s sense of their own social power, Lee and Schnall conducted three separate studies — all disguised by cover stories so that participants were unaware of what was being tested.In the first, 145 participants were asked to rank how strongly they felt a series of statements applied to them — such as “I can get people to listen to what I say” — to measure beliefs about their power in social relationships. They were then tasked with lifting a number of boxes and guessing the weight, before taking a final test to gauge their mood. Researchers found that the lower a person’s feelings of social power, the more they thought the boxes weighed.In the second test, the researchers manipulated the sense of power by asking 41 participants to sit in either an expansive, domineering position — with one elbow on the arm of their chair and the other on the desk next to them — or a more constricting one, with hands tucked under thighs and shoulders dropped.Prior to manipulation, most participants overestimated the weight; after manipulation, those who sat in the more powerful pose gave more accurate estimates, while those in the submissive condition continued to imagine heavier weight.In the final test, 68 participants were asked to recall an experience in which they had felt either powerful or powerless, and then repeatedly estimate the weights of various boxes — under the guise of studying the effect of exercise on autobiographical memory. Those who focused on the powerful incident became more accurate at guessing the weight, while those recalling a powerless situation continually overestimated the heaviness of the boxes.While previous research has shown that various physical and emotional states can influence perception of the environment — such as perceiving a hill slant to be steeper when wearing a heavy backpack, or threatening objects, such as a tarantula, appearing to be further from your face when feeling good about yourself — this is the first study to show that a sense of power can now be added to that list.Giulio Andreotti, the former Italian Prime Minister who was nicknamed ‘Il Divo’ after the epithet for Julius Caesar, famously once said that “power tires only those who do not have it.” Lee and Schnall write that this comment is “no longer an unsubstantiated conjecture,” and that their data suggests the world of the powerless “is indeed full of heavy burdens.”Added Lee: “Power plays a role when it is present in a given moment, but also when it comes to people’s personality. We find that personality, which determines how people interact with the social world, also shapes how people interact with the physical world.”

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Musical ages: How our taste in music changes over a lifetime

Oct. 15, 2013 — The explosion in music consumption over the last century has made ‘what you listen to’ an important personality construct — as well as the root of many social and cultural tribes — and, for many people, their self-perception is closely associated with musical preference. We would perhaps be reluctant to admit that our taste in music alters — softens even — as we get older.Now, a new study suggests that — while our engagement with it may decline — music stays important to us as we get older, but the music we like adapts to the particular ‘life challenges’ we face at different stages of our lives.It would seem that, unless you die before you get old, your taste in music will probably change to meet social and psychological needs.One theory put forward by researchers, based on the study, is that we come to music to experiment with identity and define ourselves, and then use it as a social vehicle to establish our group and find a mate, and later as a more solitary expression of our intellect, status and greater emotional understanding.Researchers say the study is the first to “comprehensively document” the ways people engage with music “from adolescence to middle age.” The study is published in the Journal of Personality and Social Psychology.Using data gathered from more than a quarter of a million people over a ten year period, researchers divided musical genres into five broad, “empirically derived” categories they call the MUSIC model — mellow, unpretentious, sophisticated, intense, contemporary — and plotted the patterns of preference across age-groups.These five categories incorporate multiple genres that share common musical and psychological traits — such as loudness and complexity.”The project started with a common conception that musical taste does not evolve after young adulthood. Most academic research to date supported this claim, but — based on other areas of psychological research and our own experiences — we were not convinced this was the case,” said Arielle Bonneville-Roussy from Cambridge’s Department of Psychology, who led the study.The study found that, unsurprisingly, the first great musical age is adolescence — defined by a short, sharp burst of ‘intense’ and the start of a steady climb of ‘contemporary’. ‘Intense’ music — such as punk and metal — peaks in adolescence and declines in early adulthood, while ‘contemporary’ music — such as pop and rap — begins a rise that plateaus until early middle age.”Teenage years are often dominated by the need to establish identity, and music is a cheap, effective way to do this,” said Dr Jason Rentfrow, senior researcher on the study.”Adolescents’ quest for independence often takes the shape of a juxtaposed stance to the perceived ‘status quo’, that of parents and the establishment. ‘Intense’ music, seen as aggressive, tense and characterised by loud, distorted sounds has the rebellious connotations that allow adolescents to stake a claim for the autonomy that is one of this period’s key ‘life challenges’.”As ‘intense’ gives way to the rising tide of ‘contemporary’ and introduction of ‘mellow’ — such as electronic and R & B — in early adulthood, the next musical age emerges. These two “preference dimensions” are considered “romantic, emotionally positive and danceable,” write the researchers.”Once people overcome the need for autonomy, the next ‘life challenge’ concerns finding love and being loved — people who appreciate this ‘you’ that has emerged,” said Rentfrow.”What we took away from the results is that these forms of music reinforce the desire for intimacy and complement settings where people come together with the goal of establishing close relationships — parties, bars, clubs and so on.”Whereas the first musical age is about asserting independence, the next appears to be more about gaining acceptance from others.”As we settle down and middle age begins to creep in, the last musical age, as identified by the researchers, is dominated by ‘sophisticated’ — such as jazz and classical — and ‘unpretentious’ — such as country, folk and blues.Researchers write that both these dimensions are seen as “positive and relaxing” — with ‘sophisticated’ indicating the complex aesthetic of high culture that could be linked to social status and perceived intellect, while ‘unpretentious’ echoes sentiments of family, love and loss — emotionally direct music that speaks to the experiences most will have had by this life stage.”As we settle into ourselves and acquire more resources to express ourselves — career, home, family, car — music remains an extension of this, and at this stage there are aspects of wanting to promote social status, intellect and wealth that play into the increased gravitation towards ‘sophisticated’ music,” said Rentfrow, “as social standing is seen as a key ‘life challenge’ to be achieved by this point.””At the same time, for many this life stage is frequently exhausted by work and family, and there is a requirement for relaxing, emotive music for those rare down times that reflects the other major ‘life challenge’ of this stage — that of nurturing a family and maintaining long-term relationships, perhaps the hardest of all.”Adds Bonneville-Roussy: “Due to our very large sample size, gathered from online forms and social media channels, we were able to find very robust age trends in musical taste. I find it fascinating to see how seemingly trivial behaviour such as music listening relates to so many psychological aspects, such as personality and age.”

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U. S. regions exhibit distinct personalities, research reveals

Oct. 17, 2013 — Americans with similar temperaments are so likely to live in the same areas that a map of the country can be divided into regions with distinct personalities, according to new research published by the American Psychological Association.People in the north-central Great Plains and the South tend to be conventional and friendly, those in the Western and Eastern seaboards lean toward being mostly relaxed and creative, while New Englanders and Mid-Atlantic residents are prone to being more temperamental and uninhibited, according to a study published online by APA’s Journal of Personality and Social Psychology.”This analysis challenges the standard methods of dividing up the country on the basis of economic factors, voting patterns, cultural stereotypes or geography that appear to have become ingrained in the way people think about the United States,” said lead author Peter J. Rentfrow, PhD, of the University of Cambridge. “At the same time, it reinforces some of the traditional beliefs that some areas of the country are friendlier than others, while some are more creative.”The researchers analyzed the personality traits of more than 1.5 million people. Through various online forums/media (e.g., Facebook and survey panels), participants answered questions about their psychological traits and demographics, including their state of residence. The researchers identified three psychological profiles based on five broad dimensions of personality — openness, conscientiousness, extraversion, agreeableness and neuroticism — also known as the “Big Five” personality traits. When the researchers overlaid the findings on a national map, they found certain psychological profiles were predominant in three distinct geographic areas. The data were collected over 12 years in five samples with participants from the 48 contiguous states and the District of Columbia. Overall, the samples were nationally representative in terms of gender and ethnicity, with the exception of a larger proportion of young people.”These national clusters of personalities also relate to a region’s politics, economy, social attitudes and health,” Rentfrow said. The study found that people in the friendly and conventional regions are typically less affluent, less educated, more politically conservative, more likely to be Protestant and less healthy compared to people in the other regions. …

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Sustainable livestock production is possible

Sep. 25, 2013 — Consumers are increasingly demanding higher standards for how their meat is sourced, with animal welfare and the impact on the environment factoring in many purchases. Unfortunately, many widely-used livestock production methods are currently unsustainable. However, new research out today from the University of Cambridge has identified what may be the future of sustainable livestock production: silvopastoral systems which include shrubs and trees with edible leaves or fruits as well as herbage.Professor Donald Broom, from the University of Cambridge, who led the research said: “Consumers are now demanding more sustainable and ethically sourced food, including production without negative impacts on animal welfare, the environment and the livelihood of poor producers. Silvopastoral systems address all of these concerns with the added benefit of increased production in the long term.”Current cattle production mostly occurs on cleared pastures with only herbaceous plants, such as grasses, grown as food for the cows. The effects on the local environment include the removal of trees and shrubs as well as the increased use of herbicides, all of which result in a dramatic decrease in biodiversity. Additionally, there is also contamination of soil and waterways by agricultural chemicals as well as carbon costs because of vehicles and artificial fertiliser necessary to maintain the pasture.The researchers advocate that using a diverse group of edible plants such as that in a silvopastural landscape promotes healthy soil with better water retention (and less runoff), encourages predators of harmful animals, minimizes greenhouse gas emissions, improves job satisfaction for farm workers, reduces injury and stress in animals, improves welfare and encourages biodiversity using native shrubs and trees.Additionally, shrubs and trees with edible leaves and shoots, along with pasture plants, produce more food for animals per unit area of land than pasture plants alone. Trees and shrubs have the added benefit of providing shade from hot sun and shelter from rain. It also reduces stress by enabling the animals to hide from perceived danger.”The planting as forage plants of both shrubs and trees whose leaves and small branches can be consumed by farmed animals can transform the prospects of obtaining sustainable animal production,” said Professor Broom. “Such planting of ‘fodder trees’ has already been successful in several countries, including the plant Chamaecytisus palmensis which is now widely used for cattle feed in Australia.”Another success has been in Colombia where a mixed planting of the shrub Leucaena with a common pasture grass resulted in a 27% increase in dry matter for food and 64% increase of protein production.When ruminants, such as cows, goats and sheep, are consuming the plants from a silvopastoral system, researchers have seen an increase in growth and milk production. …

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Shining stem cells reveals how our skin is maintained

Aug. 15, 2013 — All organs in our body rely on stem cells in order to maintain their function. The skin is our largest organ and forms a shield against the environment. New research results from BRIC, University of Copenhagen and Cambridge University, challenge current stem cell models and explains how the skin is maintained throughout life.The results have just been published in the journal Cell Stem Cell.New knowledge challenge stem cell modelsThe skin consists of many different cell types, including hair cells, fat- and sweat glands. It protects us against microbial and chemical attacks and forms a waterproof barrier that prevents fluid loss. Associate professor Kim Jensen’ group from BRIC have through mapping of stem cell’s behaviour in the skin found out that the skin uses a unique method to renew itself. Their results challenge the current perception of how our skin is renewed.”Until now, the belief was that the skin’s stem cells were organized in a strict hierarchy with a primitive stem cell type at the top of the hierarchy, and that this cell gave rise to all other cell types of the skin. However, our results show that there are differentiated levels of stem cells and that it is their close micro-environment that determines whether they make hair follicles, fat- or sweat glands, says Kim Jensen.The new research from Kim Jensen completes the stem cell puzzle.”Our data completes what is already known about the skin and its maintenance. Researchers have until now tried to fit their results into the old model for skin maintenance. However, the results give much more meaning when we relate them to the new model that our research proposes, says Kim Jensen.One such example is that it explains the current mystery of how skin cells can divide too much and initiate a skin cancer, without any traces of genetic change in the stem cells believed to maintain the outer layer of the skin. …

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Protein that delays cell division in bacteria may lead to identification of new antibiotics

Aug. 12, 2013 — Scientists at Washington University have worked out how two bacterial strains delay cell division when food is abundant, an understanding that might be used to design drugs that stop division entirelyIn 1958 a group of scientists working in Denmark made the striking observation that bacterial cells are about twice as large when they are cultured on a rich nutrient source than when they are cultured on a meager one. When they are shifted from a nutrient-poor environment to a nutrient-rich one, they bulk up until they have achieved a size more appropriate to their new growth conditions.It has taken 60 years to figure out how the bacteria are able to sample their surroundings and alter their cell cycles so that they grow to a size suited to the environment.In 2007 Petra Levin, PhD, a biologist at Washington University in St. Louis, reported in Cell that a soil bacterium named Bacillis subtilis has a protein that senses how much food is available and, when food is plentiful, temporarily blocks the assembly of a constriction ring that pinches a cell in two to create two daughter cells.Now Norbert Hill, a graduate student in her group, reports in the July 25 online edition of PLoS Genetics that Escherichia coli uses a similar protein to help ensure cell size is coordinated with nutrient conditions.Delaying division even just a little bit leads to an increase in daughter cell size. Once stabilized at the new size, cells take advantage of abundant nutrient sources to increase and multiply, doubling their population at regular intervals until the food is exhausted.Because both the B. subtilis and E. coli proteins interact with essential components of the division machinery, understanding how they function will help in the discovery of antibiotics that block cell division permanently. A group in Cambridge, England, is already working to crystallize the E. coli protein docked on one of the essential components of the constriction ring.If they are successful they may be able to see exactly how the protein interferes with the ring’s assembly. An antibiotic could then be designed that would use the same mechanism to prevent division entirely, killing the bacteria.Why do bacteria get bigger on a good food source?Bacteria increase and multiply by a process called binary fission. …

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Autism affects different parts of the brain in women and men

Aug. 9, 2013 — Autism affects different parts of the brain in females with autism than males with autism, a new study reveals. The research is published today in the journal Brain as an open-access article.Scientists at the Autism Research Centre at the University of Cambridge used magnetic resonance imaging to examine whether autism affects the brain of males and females in a similar or different way. They found that the anatomy of the brain of someone with autism substantially depends on whether an individual is male or female, with brain areas that were atypical in adult females with autism being similar to areas that differ between typically developing males and females. This was not seen in men with autism.”One of our new findings is that females with autism show neuroanatomical ‘masculinization’,” said Professor Simon Baron-Cohen, senior author of the paper. “This may implicate physiological mechanisms that drive sexual dimorphism, such as prenatal sex hormones and sex-linked genetic mechanisms.”Autism affects 1% of the general population and is more prevalent in males. Most studies have therefore focused on male-dominant samples. As a result, our understanding of the neurobiology of autism is male-biased.”This is one of the largest brain imaging studies of sex/gender differences yet conducted in autism. Females with autism have long been under-recognized and probably misunderstood,” said Dr Meng-Chuan Lai, who led the research project. “The findings suggest that we should not blindly assume that everything found in males with autism applies to females. …

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Explosion illuminates invisible galaxy in the dark ages

Aug. 6, 2013 — More than 12 billion years ago a star exploded, ripping itself apart and blasting its remains outward in twin jets at nearly the speed of light. At its death it glowed so brightly that it outshone its entire galaxy by a million times. This brilliant flash traveled across space for 12.7 billion years to a planet that hadn’t even existed at the time of the explosion — our Earth. By analyzing this light, astronomers learned about a galaxy that was otherwise too small, faint and far away for even the Hubble Space Telescope to see.”This star lived at a very interesting time, the so-called dark ages just a billion years after the Big Bang,” says lead author Ryan Chornock of the Harvard-Smithsonian Center for Astrophysics (CfA).”In a sense, we’re forensic scientists investigating the death of a star and the life of a galaxy in the earliest phases of cosmic time,” he adds.The star announced its death with a flash of gamma rays, an event known as a gamma-ray burst (GRB). GRB 130606A was classified as a long GRB since the burst lasted for more than four minutes. It was detected by NASA’s Swift spacecraft on June 6th. Chornock and his team quickly organized follow-up observations by the MMT Telescope in Arizona and the Gemini North telescope in Hawaii.”We were able to get right on target in a matter of hours,” Chornock says. “That speed was crucial in detecting and studying the afterglow.”A GRB afterglow occurs when jets from the burst slam into surrounding gas, sweeping that material up like a snowplow, heating it, and causing it to glow. As the afterglow’s light travels through the dead star’s host galaxy, it passes through clouds of interstellar gas. …

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Monogamy evolved as a mating strategy: New research indicates that social monogamy evolved as a result of competition

July 29, 2013 — Social monogamy, where one breeding female and one breeding male are closely associated with each other over several breeding seasons, appears to have evolved as a mating strategy, new research reveals. It was previously suspected that social monogamy resulted from a need for extra parental care by the father.The comparative study, by University of Cambridge researchers Dieter Lukas and Tim Clutton-Brock, shows that the ancestral system for all mammalian groups is of females living in separate ranges with males defending overlapping territories, and that monogamy evolved where males were unable to monopolise and defend multiple females. The research is published in the journal Science.For the study, the researchers classified all 2500 mammalian species for which information exists as either solitary, socially monogamous or group-living (several breeding females share a common range and either eat or sleep together). They showed that nine per cent of mammals are socially monogamous, including a few rodents, a number of primates, and some carnivores, like jackals, wolves, and meerkats.Previously, it had been suggested that monogamy evolved as a result of selection for paternal support in raising offspring (for example, if the female alone could not provide enough food or adequately defend the young). This study shows that paternal care usually evolved after monogamy was already present.This advance in understanding was, says Lukas, due to the volume of information they collected and the availability of genetic information that allowed the researchers to determine the sequence in which different traits evolved.”Up until now, there have been different ideas about how social monogamy in mammals evolved,” says Lukas, from Cambridge’s Department of Zoology. “With this study we were able to test all these different hypotheses at once. Paternal care evolves after monogamy is present, and seems to be a consequence rather than a cause of the evolution of monogamy. It appears to occur in about half of all socially monogamous species, and once it does evolve, it provides a clear benefit to the female.”They found convincing support for the hypothesis that monogamy arose as a mating strategy where males could not defend access to more than one female. Monogamy is associated with low density of females, low levels of home-range overlap, and indirectly, with their diets. The study showed that monogamy evolves in species that rely on high quality but patchily distributed food sources, such as meat and fruit. …

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Want to stick with your diet? Better have someone hide the chocolate

July 24, 2013 — If you are trying to lose weight or save for the future, new research suggests avoiding temptation may increase your chances of success compared to relying on willpower alone. The study on self-control by researchers from the Universities of Cambridge and Dusseldorf was published today in the journal Neuron.The researchers compared the effectiveness of willpower versus voluntarily restricting access to temptations, called ‘precommitment’. (Examples of precommitment include avoiding purchasing unhealthy food and putting money in savings accounts with hefty withdrawal fees.) They also examined the mechanisms in the brain that play a role in precommitment to better understand why it is so effective.Molly Crockett, who undertook the research while at the University of Cambridge and is currently a Sir Henry Wellcome Postdoctoral Fellow at UCL, said: “Our research suggests that the most effective way to beat temptations is to avoid facing them in the first place.”For the study, the researchers recruited healthy male volunteers and gave them a series of choices: they had to decide between a tempting “small reward” available immediately, or a “large reward” available after a delay. Small rewards were mildly enjoyable erotic pictures and large rewards were extremely enjoyable erotic pictures. Since erotic pictures are immediately rewarding at the time of viewing, the researchers were able to probe the mechanisms of self-control as they unfolded in real-time. (The scientists could not use money, for example, since subjects could only reap the rewards of money once they left the lab.)For some of the choices, the small reward was continuously available, and subjects had to exert willpower to resist choosing it until the large reward became available. But for other choices, subjects were given the opportunity to precommit: before the tempting option became available, they had the ability to prevent themselves from ever encountering the temptation.The scientists measured people’s choices and brain activity as they made these decisions. They found that precommitment was a more effective self-control strategy than willpower — subjects were more likely to get the large reward when they had the opportunity to precommit. They also found that the most impulsive people (those with the weakest willpower) benefited the most from precommitment.The scientists were also able to identify the regions of the brain that play a role in willpower and precommitment. They found that precommitment specifically activates the frontopolar cortex, a region that is involved in thinking about the future. …

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Cost of Arctic methane release could be ‘size of global economy’, experts warn

July 24, 2013 — Researchers have warned of an “economic time-bomb” in the Arctic, following a ground-breaking analysis of the likely cost of methane emissions in the region.Economic modelling shows that the methane emissions caused by shrinking sea ice from just one area of the Arctic could come with a global price tag of 60 trillion dollars — the size of the world economy in 2012.Writing in a Comment piece in the journal, Nature, academics argue that a significant release of methane from thawing permafrost in the Arctic could have dire implications for the world’s economy. The researchers, from Cambridge and Rotterdam, have for the first time calculated the potential economic impact of a scenario some scientists consider increasingly likely — that methane from the East Siberian Sea will be emitted as a result of the thaw.This constitutes just a fraction of the vast reservoirs of methane in the Arctic, but scientists believe that the release of even a small proportion of these reserves could trigger possibly catastrophic climate change. According to the new assessment, the emission of methane below the East Siberian Sea alone would also have a mean global impact of 60 trillion dollars.The ground-breaking Comment piece was co-authored by Gail Whiteman, from Erasmus University; Chris Hope, Reader in Policy Modelling at Cambridge Judge Business School, University of Cambridge; and Peter Wadhams, Professor of Ocean physics at the University of Cambridge.”The global impact of a warming Arctic is an economic time-bomb,” Whiteman, who is Professor of sustainability, management and climate change at Rotterdam School of Management, Erasmus University (RSM), said.Wadhams added: “The imminent disappearance of the summer sea ice in the Arctic will have enormous implications for both the acceleration of climate change, and the release of methane from off-shore waters which are now able to warm up in the summer. This massive methane boost will have major implications for global economies and societies.”Most discussion about the economic implications of a warming Arctic focuses on benefits to the region, with increased oil-and-gas drilling and the opening up of new shipping routes that could attract investments of hundreds of billions of dollars. However, the effects of melting permafrost on the climate and oceans will be felt globally, the authors argue.Applying an updated version of the modelling method used in the UK government’s 2006 Stern Review on the Economics of Climate Change, and currently used by the US Environmental Protection Agency, the authors calculate the global consequences of the release of 50 gigatonnes of methane over a decade from thawing permafrost beneath the East Siberian Sea.”The methane release would bring forward the date at which the global mean temperature rise exceeds 2 degrees C by between 15 and 35 years,” said Chris Hope. “In the absence of climate-change mitigation measures, the PAGE09 model calculates that it would increase mean global climate impacts by $60 trillion.”If other impacts such as ocean acidification are factored in, the cost would be much higher. Some 80% of these costs will be borne by developing countries, as they experience more extreme weather, flooding, droughts and poorer health, as Arctic warming affects climate.The research also explored the impact of a number of later, longer-lasting or smaller pulses of methane, and the authors write that, in all these cases, the economic cost for physical changes to the Arctic is “steep.”The authors write that global economic institutions and world leaders should “kick-start investment in rigorous economic modelling” and consider the impacts of a changing Arctic landscape as far outweighing any “short-term gains from shipping and extraction.”They argue that economic discussions today are missing the big picture on Arctic change. “Arctic science is a strategic asset for human economies because the region drives critical effects in our biophysical, political and economic systems,” write the academics. Neither the World Economic Forum nor the International Monetary Fund currently recognise the economic danger of Arctic change.According to Whiteman, “Global leaders and the WEF and IMF need to pay much more attention to this invisible time-bomb. The mean impacts of just this one effect — $60 trillion — approaches the $70-trillion value of the world economy in 2012.”

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