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BBSRC awards Cambridge £15 million to support next generation of scientists

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The awards are part of a £125 million investment by the BBSRC announced today by Business Secretary Vince Cable. Mr Cable said: “The UK punches far beyond its weight in science and innovation globally, which is a credit to our talented scientists and first-class universities.

“This new funding will safeguard Britain’s status as a world leader in life sciences and agricultural technology.”

The funding has been awarded to leading universities and scientific institutions across the UK through Doctoral Training Partnerships that provide skills and training for bioscience PhD students. The strategic investment will ensure that researchers are trained in areas that will benefit the UK and will help to develop new industries, products and services.

Dr Celia Caulcott, BBSRC Executive Director, Innovation and Skills: “Bioscience is having a massive impact on many aspects of our lives.  BBSRC is paving the way for an explosion in new economic sectors and bioscience that will change the way we live our lives in the twenty-first century. To achieve this we need to maintain our leading position in global bioscience by ensuring that the next generation of scientists have the best training and skills.”

The funding to Cambridge will facilitate a number of doctoral training places across the University in the School of the Biological Sciences as well as Chemistry, Physics, Applied Mathematics & Theoretical Physics, Chemical Engineering & Biotechnology, and the Institute of Metabolic Science, as well as with partner institutes including the Wellcome Trust Sanger Institute and the Babraham Institute.

Professor Graham Virgo, who takes up the post of Pro-Vice-Chancellor for Education at the University this month, says: “These Doctoral Training Partnerships will provide opportunities for exceptional students to pursue their graduate studies at Cambridge in areas of bioscience that are vital to both our future society and economy. They will bring together departments from across the University and our partner institutes in a truly cross-disciplinary manner.”

Excellent and highly skilled researchers are vital to fuelling discoveries and helping to solve some of the world's major challenges. By investing in the skills base BBSRC not only supports and develops research, but also helps to secure the nation's future, driving inward investment, creating new jobs and maintaining the UK's position as a global leader.

The University of Cambridge is to receive £15 million over five years from the Biotechnology and Biological Sciences Research Council (BBSRC) to support the training and development of 150 PhD students. Students will be trained in world-class bioscience that will help boost the economy and build on UK strengths in areas such as agriculture, food, industrial biotechnology, bioenergy and health.

These Doctoral Training Partnerships will provide opportunities for exceptional students to pursue their graduate studies at Cambridge in areas of bioscience that are vital to both our future society and economy.
Graham Virgo
Postdoctoral students

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Yes

Why a disaster may not be disastrous

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What makes a great leader? Effectiveness? Experience? Volcanoes? It might seem unlikely, but new research from a team of academics, including Raghavendra Rau, Sir Evelyn de Rothschild Professor of Finance at Cambridge Judge Business School, suggests that experiencing a natural disaster at first hand during your early childhood can have a profound impact on your strategic and tactical decisions in later life.

The team studied the impact of natural disasters on leading CEOs and, remarkably, found that those who experienced a number of moderate disasters actually had a greater appetite for risk-taking than those who had experienced none (unsurprisingly, those who experienced the most extreme natural disasters were most risk averse). It also found that they were more likely to take on more risk in response to a threat to the business.

But how do you work out who has experienced disaster – and what the impact might be? Rau and his colleagues, Gennaro Bernile and Vineet Bhagwat, came up with an ingenious solution. They constructed a database of county-level natural disasters affecting the US between 1910 and 2010, including earthquakes, volcanic eruptions, tsunamis, hurricanes, tornadoes, severe storms, floods, landslides and wildfires. They then used this data to work out the extent to which the 1,711 CEOs in the survey were likely to have been affected by these disasters between the ages of five and 15, based on the location and year of the CEO’s birth and the state in which they received their social security numbers (usually allocated during teenage years). The team included controls for the average disaster fatality risk and non-disaster geographic characteristics, such as economic conditions, crime rates and the quality of education.

The CEOs, who were all US-born and who served in S&P 1500 firms between 1992 and 2012, were then grouped into three categories: those exposed to extremely negative effects of natural disasters during their formative years; those who experienced only “medium” effects of such disasters; and those who were not exposed to disasters at all. They then examined the effect of CEO risk preferences on financial leverage, cash holdings, stock volatility, acquisitiveness and the CEO’s own compensation structure.

And the results were striking. Firms run by CEOs from the “medium” group showed a 3% higher leverage ratio than firms run by CEOs who experienced no fatal disasters; and 4.4% higher than firms led by CEOs who had experienced the most extreme negative effects of disasters.

Firms managed by these risk-loving, medium-exposure CEOs also held 0.9% less cash as a percentage of book assets than those not exposed to disaster, while those led by CEOs exposed to extremely negative effects of disaster held 0.7% more cash. Medium-exposure leaders also experienced 0.8% higher stock volatility compared to companies led by CEOs with extreme exposure or those who had not experienced disasters.

Medium-exposure CEOs were also 3% more likely to announce a corporate acquisition while at the helm. The results were strengthened if a CEO was particularly dominant – if they were also chairman or president of the board of directors. And finally, medium-exposure CEOs were also more likely to accept firm-specific risk within their compensation packages.

The team also examined what happened if a CEO was faced with disaster during their tenure. They found that only CEOs in the medium group were likely to make significant changes to corporate policies in the aftermath, reducing use of leverage and increasing cash holdings during the three years following a disaster. Those companies also tended to experience less stock volatility during the same period.

“This would appear to suggest that because these CEOs have been desensitised to risk they may underestimate the probability or costs of a disaster,” says Professor Rau.

He puts these findings into the context of research elsewhere which suggests that exposure to natural disasters can affect financial decision making in both individuals and companies. He believes this work adds to a growing body of evidence challenging the assumption in classical finance theory that managers don’t matter as much as the financial constraints within which companies operate.

He is also intrigued by findings in medical research that both supports the idea that experiencing adversity can have long-term effects on individuals, and suggests that a known biological phenomenon could drive these effects. This is co-option, in which the experience of adverse circumstances or trauma causes physiological alterations of brain development and function.

Professor Rau also highlights the fact that this research does not simply show how past experiences can affect future behaviour, but also that the way they do so is complex and non-linear. “In addition to shedding light on the causes of heterogeneous CEO behaviours, we hope our work will also help individuals in other walks of life to consider how their own backgrounds could influence their behaviour,” he says. “Our results may have implications for the growing body of work examining the effects of investors’ previous life experiences on investment strategy and portfolio allocation.” Or in other words, it pays to know about a leader’s experience, effectiveness and exposure to volcanoes.

Research shows that the behaviour of business leaders could be directly linked to their experiences in childhood.

Because these CEOs have been desensitised to risk they may underestimate the probability or costs of a disaster
Raghavendra Rau
Tsunami Hits Minamisoma

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Yes

Orchestral manoeuvres: multiple sclerosis faces the music

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The conductor walks to the stand and takes his place in front of the orchestra. He raises his baton and, with a dramatic flourish, one hundred individuals come to life. From nowhere, the stillness becomes a beautiful harmony as each member takes their part in a complex symphony.

Consider the workings and structure of the human brain – our most complicated organ – in terms of this orchestra. When it works, it is capable of something more remarkable than the greatest musical compositions in human history, but when it is affected by a condition such as multiple sclerosis (MS), “the brain’s tightly orchestrated biological functions become discordant – the conductor begins to fail at their job and several instruments go out of tune,” said Professor Robin Franklin, Head of Translational Science at the Wellcome Trust-Medical Research Council (MRC) Cambridge Stem Cell Institute and Director of the MS Society Cambridge Centre for Myelin Repair.

His research team and those led by other Stem Cell Institute researchers Drs Thóra Káradóttir, Mark Kotter and Stefano Pluchino are each looking at a different aspect of this errant orchestra. They hope that their collective knowledge will one day help ‘re-tune’ the brains of MS patients to self-repair.

In its simplest terms, MS is a disease in which the immune system turns on itself, destroying the oligodendrocytes that make a protective sheath called myelin, which encases nerve fibres. This halts the transmission of neural messages, and eventually leads to nerve fibre damage, resulting in a progressive loss of movement, speech and vision for the 100,000 people in the UK who have MS.

However, the complexities of treating the disease go beyond simply stopping the destruction of myelin, said Franklin: “The myelin damage causes a build-up of debris, which needs removing, and the environment surrounding the cells needs to be conducive to regenerating the sheath. When we think about repairing the damage, we need to be considering several different biological phenomena at the same time.”

Although there are drugs available for modifying the early stages of MS – including alemtuzumab (Lemtrada), developed in Cambridge – there are no treatments that regenerate the damaged tissue. Moreover, although the disease evolves over decades, with periods of remission followed by relapses, there is no treatment once patients have reached the progressive stage (estimated to be about 50% of current patients).

Oligodendrocytes – the master manufacturers of myelin – are formed by a type of stem cell in the brain called oligodendrocyte progenitor cells (OPCs), and are responsible for re-wrapping, or remyelinating, the bare axons with myelin in response to injuries or diseases. But this regenerative ability decreases with age and MS. “As the disease progresses, the need for intervention that galvanises the natural healing process becomes ever more important,” explained Franklin. “Working with colleagues at the Harvard Stem Cell Institute, we’ve shown that the effects of age on remyelination are reversible, which gives us some confidence that we can use the brain’s own OPCs for myelin regeneration.”

However, to understand how to stimulate the brain’s own repair mechanisms first requires an understanding of how the brain detects injury and initiates repair.

Thóra Káradóttir believes that one way the brain ‘senses’ problems are afoot is through the drop in how fast neural messages are passed across the brain. “The difference in speed between an intact neuron and a damaged one can be like comparing the speed of a cheetah to a tortoise,” she said. “I’m eavesdropping on the information superhighway by attaching electrodes to neurons and OPCs.”

Her findings show that damaged fibres release a molecule called glutamate. “It’s their ‘cry for help’ to OPCs. If it doesn’t happen, or if the OPCs don’t ‘hear’, then repair is reduced.” She is working with Numedicus, a company that specialises in developing secondary uses for existing drugs, to test drugs that she hopes will be able to amplify this signal and increase the repair process.

Meanwhile, Robin Franklin’s team has shown that it’s possible to kick-start OPCs, driving the formation of oligodendrocytes and sheath formation, using a drug that targets retinoid X receptor-gamma, a molecule found within OPCs. The results are positive and clinical trials will shortly commence in collaboration with Dr Alasdair Coles from the Department of Clinical Neurosciences and the MRC Centre for Regenerative Medicine at the University of Edinburgh.

What’s interesting about the rejuvenation of remyelination is that the treatment primarily affected inflammation in demyelinating lesions, and specifically the recruitment of cells called macrophages. These are the body’s ‘big eaters’ – their role is to search out and gobble up rubbish. “We have identified myelin debris as a potent inhibitor of stem cells. Learning how it is being sensed by stem cells enabled us to overcome this inhibition by using drugs such as ibudilast.  A clinical trial to test these effects is currently undergoing preparation,” explained Mark Kotter.

Franklin and Kotter’s work is representative of an interesting turn in MS research within the field. Increasingly, investigators are looking at how the environment around the damage can be improved to help natural remyelination. “It’s a curious paradox,” said Franklin. “MS is caused by the immune system but components of the immune system are also key to its recovery.”

Stefano Pluchino’s team, for instance, has shown that injecting brain stem cells into mice with MS works in a surprising way. Instead of making new oligodendrocytes (or other brain cells), the cells seem to work by re-setting the damaging immune response, creating better conditions for the brain’s own stem cells to replace or restore what has been damaged. He is now developing more-efficient stem cells and new drugs, including nanomedicines, to foster the healing of the damaged brain.

Given the complex landscape of abnormal activities happening in the MS brain, will combination therapies be the way forward? “Certainly,” said Franklin. “Over the next ten years we will see an increased understanding of the fundamental biology in MS, we will identify more targets which may yield effective drugs and we’ll have more-refined strategies for running clinical trials. What makes Cambridge rare is the spectrum of skills here – from understanding the fundamental biology of myelin repair through to clinical trials.”

Inset image left to right: Robin Franklin, Thóra Káradóttir, Mark Kotter and Stefano Pluchino

Like conducting an errant orchestra to play together, researchers are guiding processes that go awry in multiple sclerosis to repair themselves.

MS is caused by the immune system but components of the immune system are also key to its recovery
Robin Franklin
Conductor's baton

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Yes

The speech that never was – Thatcher papers for 1984 open to the public

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Draft pages of her intended speech – grabbed from the wreckage of the Grand Hotel following the attack on the Prime Minister on October 12, 1984 – detail how Thatcher planned to warn the country from the podium of the Conservative Party Conference that Britain faced ‘an insurrection’.

The ‘speech that never was’ went on to suggest that the Labour Party was the ‘natural home’ of forces whose ambition was to tear the country apart ‘by an extension of the calculated chaos planned for the mining industry by a handful of trained Marxists and their fellow travellers’.

Her own handwritten notes for the speech, released today by the Churchill Archives Centre (www.chu.cam.ac.uk/archives) and online at the Margaret Thatcher Foundation website (www.margaretthatcher.org ), suggest plans to link what she regarded as militant mining communities to General Galtieri – the Argentinian dictator defeated during the Falklands War of 1982. The note, released for the first time, reads: “Since Office. Enemy without – beaten him & resolute strong in defence. Enemy within – Miners’ leaders…Liverpool and some local authorities – just as dangerous…in a way more difficult to fight…just as dangerous to liberty.”

Chris Collins from the Margaret Thatcher Foundation, the only historian to date to have had unrestricted access to the papers, said: “It was a speech which would have been remembered as controversial and would have eclipsed the ‘enemy within’ speech (delivered in private to the backbench 1922 Committee) Indeed it was intended to do that.

“There’s a certain irony that an act of great violence actually softened this speech. In the end, the original speech was torn up and later taped back together, probably by Thatcher herself, who was a dab hand with Sellotape.”

Among the other 40,000 papers being released online and at Churchill College, are documents which reveal the Prime Minister’s deep sense of foreboding about her fate at the hands of the Conservative Party she ruled, prophesising events of seven years later when she would be forced to resign as PM.

She told her secretary John Coles that: “My party won’t want me to lead them into the next election – and I don’t blame them.” Collins said he was amazed to find Mrs Thatcher imagining her own downfall just days after the 1983 General Election victory.  The account, written when Coles left Number 10 in June 1984, also reveals that Thatcher’s doubts ran in parallel to a ‘decline in her energy’ after the election win.

More light-hearted pages from the 1984 archive reveal the prickly saga of a rose called Margaret, detailing – in a scene that could have been lifted straight from the scripts of Yes Prime Minister – how an innocent flower sparked a potential diplomatic incident between West Germany and Japan.

The drama began in innocent enough fashion when a West German horticultural association asked for permission to name a rose after Margaret Thatcher, delighting officials in Whitehall wishing to perhaps promote a softer side to the ‘Iron Lady’.

However, the Prime Minister had forgotten an agreement of six years earlier, signed while Leader of the Opposition, that had given a Japanese firm license to grow the original ‘Margaret Thatcher Rose’.

The clearly wounded Japanese firm wrote to the PM’s office and the Whitehall machine acted swiftly to pour oil on troubled diplomatic waters. The incident provoked many pages of notes between Whitehall and Foreign Office officials. In the end, it took a letter from private secretary Charles Powell to draw matters to a close. His reassuring tones of diplomacy to the slighted Japanese company headed off any threats of legal action and potential embarrassment to the Thatcher office.

Andrew Riley, Archivist of the papers at the Churchill Archives Centre, said: “This release of papers gives us a vivid insight into life at Downing Street and into Mrs Thatcher’s state of mind during a very difficult year, both personally and politically.

“The papers provide fresh insights into the often bitter coal strike of 1984, as well as newly released materials on the impact and aftermath of the Brighton bomb.”

 

Papers opened to the public today reveal how the Brighton bombing stopped Margaret Thatcher from widening her infamous ‘enemy within’ rhetoric to include not only the striking miners but also the wider Labour movement and Party.

It was a speech which would have eclipsed the ‘enemy within’ speech.
Chris Collins
A Sellotaped page from the speech that never was

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Yes

Mistress, Miss, Mrs or Ms: untangling the shifting history of titles

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In July composer Judith Weir was named as the first woman to hold the post of Master of the Queen’s Music, following in the footsteps of dozens of eminent male musicians with the same title. The Guardian reported that “the palace never even suggested ‘mistress’ of the Queen's music and neither did she”. 

When the role Master of the King’s Music was created in 1626, the words master and mistress were direct equivalents. Today mistress carries multiple connotations, one of which the Daily Mail alluded to in a headline before the announcement asking if Weir might be the Queen’s first Music Mistress.

Research by Cambridge University historian Dr Amy Erickson, published in the autumn issue of History Workshop Journal, unravels the complex history of an extraordinarily slippery word and suggests that the title of Mrs, pronounced ‘mistress’, was for centuries applied to all adult women of higher social status, whether married or not.

Erickson’s inquiries into forms of female address emerged from her study of women’s employment before the advent of the national census in 1801. What she found in registers, records and archives led her to question existing assumptions and track the changes that have taken place in the history of titles.

She says: “Few people realise that ‘Mistress’ is the root word of both of the abbreviations ‘Mrs’ and ‘Miss’, just as Mr is an abbreviation of ‘Master’. The ways that words derived from Mistress have developed their own meanings is quite fascinating and shifts in these meanings can tell us a lot about the changing status of women in society, at home and in the workplace.”

Throughout history ‘mistress’ was a term with a multiplicity of meanings, like so many forms of female address. In his Dictionary of 1755, Samuel Johnson defined mistress as: “1. A woman who governs; correlative to subject or servant; 2 A woman skilled in anything; 3. A woman teacher; 4. A woman beloved and courted; 5. A term of contemptuous address; 6. A whore or concubine.”

Neither ‘mistress’ nor ‘Mrs’ bore any marital connotation whatsoever for Dr Johnson. When in 1784 he wrote about having dinner with his friends “Mrs Carter, Miss Hannah More and Miss Fanny Burney”, all three women were unmarried. Elizabeth Carter, a distinguished scholar and lifelong friend of Johnson’s, was his own age and was invariably known as Mrs Carter; Hannah More and Fanny Burney were much younger and used the new style Miss.

Erickson’s investigations have revealed that ‘Miss’ was adopted by adult women for the first time in the middle of the 18th century. Before that, Miss was only used for girls, in the way that Master is only ever (today increasingly rarely) used for boys. To refer to an adult woman as a ‘Miss’ was to imply she was a prostitute.

She explains: “Until the 19th century, most women did not have any prefix before their name. Mrs and, later, Miss were both restricted to those of higher social standing. Women on the bottom rungs of the social scale were addressed simply by their names. Thus, in a large household the housekeeper might be Mrs Green, while the scullery maid was simply Molly and the woman who came in to do the laundry was Tom Black's wife or Betty Black.

“Historians have long known that Mrs indicated social status, but they normally assume it also shows that the woman was married. So they have wrongly concluded that women like Johnson's friend Elizabeth Carter were addressed as Mrs as an acknowledgement of distinction, to grant them the same status as a married woman.”

Erickson suggests that this interpretation is mistaken. “Mrs was the exact equivalent of Mr. Either term described a person who governed servants or apprentices, in Johnson's terms – we might say a person with capital. Once we adopt Johnson's understanding of the term (which was how it was used in the 18th century), it becomes clear that ‘Mrs’ was more likely to indicate a businesswoman than a married woman. So the women who took membership of the London Companies in the 18th century, all of whom were single and many of whom were involved in luxury trades, were invariably known as ‘Mrs’, as the men were ‘Mr’. Literally, they were masters and mistresses of their trades.”

Historians have often misidentified women as married because they were addressed as ‘Mrs’ – when they were actually single. “It's easy enough to identify the marital status of a prominent woman, or those taking the Freedom of the City of London (since they had to be single),” says Erickson. “But it’s much harder to identify whether those women described as Mrs in a parish listing of households were ever married - especially the ones with common names like Joan Smith.”

A 1698 tax list from Shrewsbury lists from the top: William Prince Esqr Mm [Madam] Elizabeth Prince Wdd [widow] Mm Mary Prince Wdd Ms [mistress] Mary her daughter Mm Judeth Prince Mr Philip Wingfield Bat [baronet] Ms Gertrude Wingfield [who is either the wife or the daughter of Mr Wingfield above] followed by a number of women below with only a first and last name. This example shows that not all women had a title in front of their name, and demonstrates the use of Ms for an unmarried women (Mary Prince) and for a woman whose marital status is unclear (Gertrude Wingfield). Madam appears to be used here as the title for married/widowed women of social standing.

Erickson’s research into the 1793 parish listing for the Essex market town of Bocking shows that 25 heads of household were described as Mrs. She says: “Female household heads were by definition either single or widowed and, if Bocking was typical of other communities, around half of them would have been widows, and the other half single. But two thirds of these women in Bocking were specified as farmers or business proprietors. So Mrs is more reliably being used to identify women with capital, than to identify marital status. Only one woman was Miss: the schoolmistress.”

It seems that it was not society’s desire to mark either a woman’s availability for marriage (in the case of ‘Miss’), or to mark the socially superior status of marriage (‘Mrs’) which led to the use of titles to distinguish female marital status. Rather, socially ambitious young single women used ‘Miss’ as a means to identify their gentility, as distinct from the mere businesswoman or upper servant.

This trend was probably fuelled by the novels of the 1740s such as those by Samuel Richardson, Henry Fielding and Sarah Fielding, which featured young gentry Misses and upper (single) servants titled Mrs. The boundaries between the old and new styles are blurred, but Mrs did not definitively signify a married woman until around 1900.

In the course of her research, Erickson has also looked at the way in which from the early 19th century married women acquired their husband’s full name – as in Mrs John Dashwood (Jane Austen’s Sense & Sensibility, 1811). Austen used this technique to establish seniority among women who shared the same surname. England in the early 19th century was the only place in Europe where a woman took her husband's surname

To many women in the late 20th century, the practice of replacing her first name by his first name added insult to injury. That's why this form of address was satirised as “Mrs Man", and why it has dropped out of use in all but the most socially conservative circles – except of course where a couple are addressed jointly. The introduction of Ms as a neutral alternative to 'Miss' or 'Mrs', and the direct equivalent of 'Mr', was proposed as early as 1901.

“’Those who objected to ‘Miss’ and ‘Mrs’ argue that they define a woman by which man she belongs to. If a woman is ‘Miss’, it is her father; if she is addressed as ‘Mrs’, she belongs to her husband,” says Erickson. “It’s curious that the use of Ms is often criticised today as not 'standing for' anything. In fact, it has an impeccable historical pedigree since it was one of several abbreviations for Mistress in the 17th and 18th centuries, and effectively represents a return to the state which prevailed for some 300 years with the use of Mrs for adult women – only now it applies to everyone and not just the social elite.”

The question of which titles are appropriate for which women is likely to remain hotly contested. In 2012 the mayor of Cesson-Sevigne, a town in France, banned the use of ‘mademoiselle’ (the French equivalent of ‘Miss’), in favour of madame (the equivalent of ‘Mrs’), which would be applied to all women, whether married or not, and regardless of age. The proposal has not met with universal favour. Some women protested that calling an adult woman ‘mademoiselle’ was a compliment.

Dr Amy Erickson's paper, ‘Mistresses and Marriage’, is published in the autumn 2014 issue of History Workshop Journal. Her research on this topic is one thread of a much larger University of Cambridge project that will eventually reconstruct the occupational structure of Britain from the late medieval period to the 19th century. http://www.geog.cam.ac.uk/research/centres/campop/

In a paper published in the autumn issue of History Workshop Journal Dr Amy Erickson unravels the fascinating history of the titles used to address women. Her research reveals the subtle and surprising shifts that have taken place in the usage of those ubiquitous M-words. 

‘Mistress’ is the root word of both of the abbreviations ‘Mrs’ and ‘Miss’, just as Mr is an abbreviation of ‘Master’. The ways that words derived from Mistress have developed their own meanings is fascinating and shifts in these meanings can tell us a lot about the changing status of women."
Amy Erickson
1698 tax list from Shrewsbury

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Yes

Luck and lava

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The team, led by Professor Bob White, has been monitoring activity near the Bárðarbunga and Holuhraun volcanoes since 2006, using up to 70 broadband seismometers.

Luckily, the seismometers and field researchers were still in Iceland at the time that this most recent volcanic activity began, as the team had recently finished recovering 25 seismometers from the Vatnajökull ice cap where they had been used for a study of small quakes caused by ice cracking.

Here, White and PhD student Tim Greenfield discuss their work, and what it’s like to be up close to such a spectacular eruption.

A team of researchers from Cambridge’s Department of Earth Sciences have recently returned from Iceland where, thanks to a bit of luck, they have gathered the most extensive dataset ever from a volcanic eruption, which will likely yield considerable new insights into how molten rock moves underground, and whether or not it erupts.

Aerial view of Bárðarbunga

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Yes

Can she bake? The Bake Off back story

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More than 10 million of us are watching it and we’ve bought the recipe books: once again Great British Bake Off has taken the nation by storm with the high drama of pastry, pies and profiteroles. But how many of us keep our households supplied with home-made bread and cakes, let alone have the skills to rustle up a perfect gooseberry tart or a faultless chocolate roulade?

In his book Cottage Economy, first published in 1821, the reforming journalist William Cobbett laments the decline in baking. “As to the act of making bread, it would be shocking indeed if that had to be taught by means of books. Every woman high or low, ought to know how to make bread. If she does not, she is unworthy of trust and confidence: and indeed a mere burden on the community. Yet it is but too true, that many women, even those who get their living from their labour, know nothing of the making of bread.”

Cobbett’ was a farmer as well as a writer. His purpose in writing Cottage Economy was to promote self-sufficiency in the rural labouring classes. Elsewhere in the book, he counsels readers to ensure that their daughters learn to bake in order to command a better wage as servants. “’Can she bake?’ is the question that I always put. If she can then she is worth a pound or two a year more.”

Sophie McGeevor, a PhD candidate in the Faculty of History, is studying women’s work in mid-19th century England as part of a major longitudinal study of employment. In particular, McGeevor looks at the use of time, building a picture of the ways in which women divided their waking hours between paid and unpaid work as they carried out essential but often overlooked household tasks such as laundry, caring, mending and cooking. 

She says: “What interests me about Cobbett’s writing is that in advocating self-sufficiency, he was calling for a way of life which was both home-based and incredibly time intensive – and which was, in many ways, incompatible with remunerative work available to women in this period.”

Home baking was central to the kind of wholesome and resourceful domesticity that Cobbett promoted. It was an activity far removed from today’s image of baking as a fun and fulfilling hobby – and it was undertaken almost exclusively by women. McGeevor’s research into a collection of autobiographies held by the British Library shows that many households baked just once a week when the oven would be lit especially for the purpose. 

A batch of loaves that was fresh out of the oven on a Wednesday would be eaten stale by the following Tuesday. Heating an oven to exactly the right temperature for baking, and juggling the baking of various products, was an art. For many families, burnt or undercooked goods would be a disastrous waste of precious resources – ingredients, fuel and time - not simply a question of a petulant Bake Off binning.

An autobiography written by Louise Jermy, who was born in 1877, illustrates just what an undertaking ‘baking day’ was for households adhering to what were already old-fashioned traditions. Sent from London to the country to recover from an illness, Louise describes her Aunt Anne baking once a fortnight, producing rabbit and hare pies, fruit tarts and batch cakes, as well as bread. All these are cooked in a brick oven heated by “three large faggots of thorns” … “when the oven is white hot it was scrapped out, and then mopped to clean the ashes and the door was fastened”.

Notes made by Louise show the times involved in baking various items: batch cakes 1 ½ hrs; buns “about a quarter”; “sweet cakes and pies about one and a half to two hours”; “the large loaves were left for two and a half hours”. Such was the hard work and time involved in this task that Aunt Ann has made a neat arrangement with her daughter-in-law. The two women bake on alternate weeks “whichever one baked would make a good supply of batch cakes, each sending fresh ones, exchanging every week so that we had some fresh bread”. 

A stove was not just expensive to heat but, in summer especially, it made a small house uncomfortably hot. Nellie Hoare, born in 1898, remembers: “There was a bakery not far from us and often I have taken a dough-cake Mother had made or a bread pudding and they would bake it. They would do this for anyone if it was taken in before nine in the morning and it could be fetched about three hours later for the price of one penny. People used to take more things to bake in the summer time as no-one wanted to keep up the fire enough for baking at home then. Of course we had to keep some sort of fire going at home winter and summer as we had nothing else to boil a kettle or do any cooking.”

It’s notable that at the end of the 19th century Louise’s aunt is making cakes and Nellie’s mother is sending her out with puddings to cook. Widespread evidence for working class consumption of baked sugary cakes and puddings cannot be found until the 15th century and they remained luxury items well into the 1800s.

“Though labouring people had begun to consume sugar in increasing quantities over the course of the 18th century, it was generally eked out in weak tea and not used in everyday baking. It was not until the mid-19th century, with the push for free trade and the abolition of preferential duties for British Colonies beginning with the Sugar Duties Act of 1846, that a huge fall in the price of sugar made the eating and baking of cakes and biscuits more affordable,” said McGeevor.  

“Today home bread-making is chiefly a matter of choice and privilege. It’s something people do as a leisure activity using a bread maker or a modern oven which heats up in minutes. In the 19th century, bread was the mainstay of the English diet, eaten several times a day, and baking was a heavy and laborious process.” 

A common misconception, however, is that all women made bread for their families. Women who worked outside the home would not have been able to spend a whole day baking. Families who lived in areas where fuel was expensive showed a preference for buying ready-made bread. 

Another big factor in the mix was fuel.  Baking in an oven required substantial quantities of wood and/or coal. Coal was cheap in areas close to coal fields but more expensive the further it had to be transported. So that even William Cobbett admitted that for families in London making their own bread might be uneconomic. 

In the 1870s, a French engineer called Frederic Le Play made a detailed study of the daily life of more than 60 labouring families. Four of these families were English. Comparing the household budgets of two cutlers with similar sized households – one in London and the other in Sheffield – he showed that the Sheffield family consumed 6,150 kg of coal against the London family’s 4,064 kg, reflecting the cheaper prices of the north.

“The disparity in coal prices may explain why the family in Sheffield made their own bread while the London family brought their bread from a baker,” said McGeevor. “The Sheffield cutler, his wife and three children consumed 1,272 lbs of flour per year which equates to at least three 2lb loaves each day, all baked by the cutler’s wife. This level of consumption seems staggeringly high to us but it fits with other evidence we have of per capita consumption of bread.”

Regional cookery is shaped not just by availability of ingredients but also by the source of heat available to cook food on or in – and by the time that can be devoted to the task. “Many regional specialities originate from baking not in an oven but on an open fire. In peat-burning areas, bread and pies could be baked in cast-iron pots, known as Dutch ovens, which were placed in the ashes,” said McGeevor.

“Oatcakes, griddle cakes, Welsh cakes and drop scones – as well as delicious pancake-like cakes still available in Derbyshire and Staffordshire – were cooked on a cast-iron griddle or bake-stones heated by an open fire. All these items are much quicker and less laborious to cook than bread – and they are cheap, tasty and filling.”

The Bake Off phenomenon draws heavily on a brand of cakes-as-comfort-food nostalgia that has little to do with reality. “Many of us have embraced home-baking as a result of the show and some of us are encouraged by memories of our grandmothers’ creations. We would, however, be mistaken to assume that home baking was part of women's lives for several generations before,” said McGeevor.

“Women’s work has always been constrained by time and resources. How many of us would be enthusiastic about baking if we had first to light the oven with a pile of sticks and didn’t have the option of popping into a supermarket if it all goes wrong?”

Inset images: image from household guide (Smithsonian Libraries); oven featured in Cassell's Household Guide (Wikia); medieval baker (Wikipedia)

 

As Great British Bake Off sizzles towards tomorrow’s final, historian Sophie McGeevor reveals the less glamorous realities that faced working class women in the mid-19th century when home baking was already considered a dying art. 

Today home bread-making is chiefly a matter of choice and privilege. It’s something people do as a leisure activity. In the 19th century, bread was the mainstay of the English diet, eaten several times a day, and baking was a heavy and laborious process.”
Sophie McGeevor
Painting of a woman making oat cakes by George Walker (1781-1856)

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Yes

Out of the red and into the blue: making the LED revolution cost-effective

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British manufacturer Plessey Semiconductors is racing to be the first company to make energy-efficient LEDs for home lighting at a price that consumers will pay, and they’re using a technology developed by Cambridge researchers.

In 2012, Plessey acquired technology to grow a remarkable man-made material that can emit light in every part of the colour spectrum when electricity passes through it. They recommissioned a mothballed processing plant, created new jobs and hired three researchers from the University of Cambridge. Their aim: to put energy-efficient lighting within financial reach of the consumer.

Prototypes of their light-emitting diodes (LEDs) rolled off the production line later that year, and by April 2013 the company was gearing up to fulfil its first commercial orders. In just 15 months, Plymouth-based Plessey had gone from never having made an LED to being the world’s first manufacturer of commercially available LEDs made on large-diameter silicon substrates.

Today, the company is addressing a global market that, according to a report released in 2013 by WinterGreen Research, could be worth up to $42 billion by 2019.What gives Plessey an edge over its competitors is its ability to manufacture LEDs at a fraction of their costs, thanks to a unique process developed by Professor Sir Colin Humphreys in the Cambridge Centre for Gallium Nitride.

Blue and white gallium nitride (GaN) LEDs have been commercialised around the world since Shuji Nakamura in Japan developed a method of growing thin GaN layers on sapphire in the early 1990s. Although GaN LEDs are now expected to dominate the world market for lighting, their performance and cost both need to be improved.

Humphreys’ team has developed a way of growing GaN on the vastly cheaper substrate silicon and, crucially, a means of scaling this up for commercial purposes. “We’ve got lower costs for growing GaN LEDs on silicon than anyone else we know,” explained Humphreys. “Potentially, this is an advantage that puts Britain right at the forefront of LED research.”

Competition between manufacturers (including Toshiba and Samsung) to lead the market in competitively priced LEDs has been intense, driven by the increasing demand for energy-efficient lights.

LED bulbs have much longer working lives than any other forms of artificial lighting: LEDs can last for 100,000 hours compared with 10,000 hours for fluorescent tubes and 1,000 hours for tungsten filament light bulbs. LEDs in dashboards frequently outlive the life of the car; LED light bulbs in the home would probably have to be changed only once in a person’s lifetime.

LEDs also use less energy than other forms of lighting. UK homes use 20% of their energy on lighting and, because LEDs use 90% less energy than incandescent bulbs, Humphreys estimates that the superior energy efficiency of LEDs could save the UK £2 billion per year in energy, and reduce CO2 emissions. It’s little wonder that LEDs have been hailed as a lighting revolution.

Yet, few homeowners have invested in LEDs for home lighting. “A 48-watt equivalent LED bulb costs around £15. Although it will save people money over its lifetime, very few people will pay this. We think we can reduce the cost to £3,” said Humphreys.

Humphreys’ team has pioneered a technique for depositing successive layers of GaN and indium GaN, each only 5–10 atoms thick and growing at the speed of grass, on a six-inch silicon wafer. The wafer is then cut into up to 150,000 pieces, each of which forms the heart of a small LED. Using this technology, Plessey hopes to become the commercial leader in GaN-on-silicon LEDs, producing billions per year.

“Growing GaN on silicon is quite a complex process,” said Humphreys. A particular problem is the appearance of cracks on cooling from the growth conditions of 1,000°C. This has now been solved by the researchers through careful balancing of the tension in the material as it cools down.

Plessey acquired the technique when it bought the spin-out company CamGaN, set up by Humphreys and colleagues to commercialise the technology. The size of the silicon wafers is greater than the conventional two-inch sapphire wafers, meaning a greater number of LEDs can be made. Fortuitously, Plessey had a six-inch processing line that had been mothballed.

“When we launched CamGaN, we were contacted by companies all over the world wanting to utilise the technology,” said Humphreys. “The research has been funded by government money through the Engineering and Physical Sciences Research Council (EPSRC) and it was important to us that this research be exploited here in the UK.”

Meanwhile, the researchers are continuing their work with what Humphreys describes as a “truly remarkable” material. A new £1 million growth facility funded by the EPSRC and made by AIXTRON Ltd, a long-term collaborator of Humphreys’ research group, has been installed in Cambridge, where the researchers are adjusting minute aspects of the growth process to improve the efficiency of light emission.

The benefits of increased efficiency could go far beyond home lighting, and the researchers are now looking at applications that extend from biomedicine to power electronics.

In collaboration with the University of Manchester, they plan to build tiny LED devices that can be implanted by keyhole surgery in cancer patients being treated with radiotherapy. “If a patient moves while an X-ray or proton beam is directed at their tumour, then they risk healthy tissue being damaged,” explained Humphreys. “An LED attached to a sensor would detect movement at the site of the tumour in order to redirect the beam.”

Even tinier devices are being investigated as a means of firing single neurons in the brain. Working with US researchers involved in the Brain Activity Map Project – a flagship initiative of the Obama administration – the researchers will supply LEDs that can be implanted in the brain with the goal of mapping the activity of every neuron, to understand how the brain works both in health and disease.

Water purification is another area where LEDs could benefit the health of millions. “Life on earth has developed in the absence of deep UV and so we can kill bacteria and viruses by damaging their DNA with deep UV light,” he said. The idea is to have a ring of LEDs powered by solar cells on the inside of water pipes. “We now have LEDs with the right energy level to do this, we just need to increase the intensity.”

Collaborative projects with the Universities of Glasgow and Strathclyde are also investigating GaN transistors as power electronics in devices that manage electrical energy and LEDs as light-based Wifi (so-called Li-Fi). Humphreys believes that the day will arrive when GaN devices will light our homes, power our mobile phones, laptops, cars and aircraft engines, and connect us wirelessly to information transmitted from traffic lights and street lights.

“In addition to the £2 billion per year in electricity savings from GaN LEDs, GaN transistors could help the UK save £1 billion from power electronics and 15–20% in carbon emissions, and GaN UV LEDs could save millions of lives,” said Humphreys. “It’s the ultimate shopping list.”

Plessey, in the meantime, is focusing on product improvement and reduction in cost. “There are huge players in the market but we were first to market with GaN-on-silicon LEDs,” said Dr Keith Strickland Chief Technology Officer of Plessey. “Our continuing relationship with the Cambridge research group will help us push this technology to its highest potential.”

Today, the Nobel Prize for Physics 2014 has been awarded to Isamu Akasaki, Hiroshi Amano and Shuji Nakamura for their invention of a new energy-efficient and environment-friendly light source – the blue light-emitting diode (LED). University of Cambridge researchers are building on their work to produce more cost-effective gallium nitride LEDs that can have widespread use in homes and offices.

We’ve got lower costs for growing GaN LEDs on silicon than anyone else we know; potentially, this is an advantage that puts Britain right at the forefront of LED research
Colin Humphreys
Electron diffraction pattern of a thin film made of gallium nitride

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Yes

Ex-BP chief explains why coming out is good business

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Drawing on his experiences as a closeted gay man in the oil industry, and the experiences of other prominent executives from around the world, Lord Browne argues that coming out is best for employees and the companies that support them.

“I wish I had been brave enough to come out earlier during my tenure as chief executive of BP. I regret it to this day. I know that if I had done so I would have made more of an impact for other gay men and women. It is my hope that the stories in this book will give some of them the courage to make an impact of their own,” he said.

The Madingley Lectures are a series of free public lectures given by leading authorities in their fields. They take place at Madingley Hall, home of the University of Cambridge Institute of Continuing Education, and are an important part of the Institute's commitment to public engagement. Previous speakers have included Lord Rees, the Astronomer Royal and Professor Sir Leszek Borysiewicz, Vice-Chancellor of the University of Cambridge.

For further information, see: www.ice.cam.ac.uk/madingleylectures

Today gay men and women in the Western world enjoy greater acceptance and legal protections than ever before. Yet an alarming number of businessmen and women choose to remain closeted at work. Lord Browne of Madingley, the former chief executive of BP, will give a public lecture at Madingley Hall today (8 Oct) about his new book, The Glass Closet.

I wish I had been brave enough to come out earlier during my tenure as chief executive of BP. I regret it to this day.
Lord Browne of Madingley
Rainbow flag : banner, Harvey Milk Plaza, Castro, San Francisco (2012) - cropped

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Yes
License type: 

Adapt and survive: how conservation and animal psychology can work together

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For decades, the lighthouse at Bardsey island in north Wales has shone its sweeping white light out across the Irish Sea at night, keeping sailors safe.  However, the bright beam, which extends 22 miles across the water and is the only light source in the area, has also been implicated in the deaths of thousands of migrating birds who instinctively head towards it and often collide with the lighthouse. On one night in 2003, 40,000 birds landed on the island. Later this year the white light will be replaced by an intermittent red light in a move wildlife experts say could save large numbers of birds’ lives.

Scientists at the Universities of Cambridge and Exeter say this kind of action shows how research on animal behaviour can be used in conservation to mitigate the damage effects of humans on other species. They are calling for closer collaboration between conservationists and animal experts and are building a database to make it easier for conservationists to make use of existing research.

They say that while some animals have shown a remarkable ability to adapt to the impact humans have had on their environment, others have had to put up with the disastrous consequences of life lived in the human shadow. Understanding what drives animals’ perceptual and learning systems may significantly improve their outcome. In the case of birds, for instance,  studies show changing the colour of the light emitted by a lighthouse makes birds less likely to be attracted to it.

In a recent paper in Trends in Ecology and Evolution, specialists in animal cognition, including Professor Nicky Clayton from the University of Cambridge’s Department of Psychology, argue that by understanding animals' behaviour, scientists can "purposefully alter" how they respond to their environment in ways that can help preserve them.

They write: "Despite the fundamental connection between cognition and behaviour, the breadth of cognitive theory is under-utilised in conservation practice. Bridging these disciplines could augment existing conservation efforts targeting animal behaviour."

The paper outlines relevant principles of perception and learning and develops a step-by-step process for applying aspects of cognition towards specific conservation issues. For instance, the authors point out that animals flee disturbances such as the sound of mine blasts, which wastes energy and feeding time. Through understanding their behaviour and responses, scientists can seek to decrease the extent to which blasts cause avoidance behaviour and help them get used to the noise so that the blasts no longer cause alarm, for instance, by detonating blasts at the same time daily which can make cues more predictable.

The authors conclude: "With shared conservation goals, comparative psychologists can direct their research towards species of conservation concern, and conservationists can benefit by applying new cognitive insights to difficult problems.”

Gates Cambridge Scholar Alison Greggor, lead author on the paper, says: “Animals are inherently guided by cognitive biases that influence which perceptual cues they attend to, and which associations they learn. If we can understand which cues animals use to guide their behaviour, we can target these cues in a specific manner to change their behaviour.”

This might not be a case of simply teaching them to adapt to human-dominated environments, although this might be useful in some situations because sometimes the issue is how animals perceive a signal. By changing a signal, such as the lighthouse beam, animals may no longer respond to a stimulus in a negative way.

Greggor, who is doing a PhD in Experimental Psychology, is studying the impact of humans on jackdaws, how their habitat – whether rural or city – makes a difference and whether some birds are more successful when they act in a certain way around humans.

“I'm interested in the interaction between animals and humans, something that is vital as our influence gets larger and larger,” she says. Before starting her work on jackdaws, she worked on the SAPPHIRE project in Hawaii looking at the impact of tourists on dolphin behaviour.

The dolphins came inland to sleep during the day to escape potential dangers from predators. Alison and her colleagues observed their behaviour and were able to recognise individual dolphins and their movements from the marks on their fins. She says that when they are at rest the dolphins tend to move in a tight pack and come up slowly for air. However, the researchers observed that when they were in areas where there was a lot of tourist activity the groups would break up and become agitated. Some would avoid going into the bays altogether. “Their response was a very obvious direct result of human activity day after day. If they don't get enough sleep they are not as vigilant to predators and not as efficient in getting prey. The long-term impact is huge,” she says.

Although the fundamental principles of animal cognition have been well studied for decades, it is only within the past 10 years or so that people have begun to see behaviour as something that impacts conservation outcomes.

“In our journal article, we advocate taking things a step farther. Since cognition drives behaviour, we can use our knowledge of cognitive mechanisms to most efficiently shape the behaviour we want to change,” says Greggor. “This has been slowly happening in selected management areas, such as in encouraging hatchery reared-fish to prefer the correct type of stream, or identifying the types of signals that create perceptual errors, but there is a long way to go before the two fields are integrated.”

The journal article, published in July, has pushed forward the debate and has already generated discussion, including a formal reply letter and a response from the authors,published this week. Ultimately, however, Greggor says that the theories the authors propose to aid conservation policies need to be made accessible to those forming management policy and conservation programmes.

The Cambridge team, along with international collaborators and Alex Thornton at the University of Exeter,  therefore plan to create a database where this type of information is available to those in the conservation field. They are setting up a website based on the example of the Conservation Evidence site run by Professor Bill Sutherland and his colleagues in the Zoology Department (ConservationEvidence.com).  This is a free, information resource designed to support decisions about how to maintain and restore global biodiversity through the publication of summarised evidence from scientific literature about the effects of conservation interventions such as species management. Greggor is optimistic the site will turn academic research into conservation action on the ground. She says: “We are perfectly set up in Cambridge to work together and actually make this happen.”

Researchers are calling for animal cognition experts and conservationists to come together to help animals adapt their behaviour to changing environmental issues and aid their own preservation.

Animals are inherently guided by cognitive biases that influence which perceptual cues they attend to, and which associations they learn. If we can understand which cues animals use to guide their behaviour, we can target these cues in a specific manner to change their behaviour.
Alison Greggor
La Hague lighthouse

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Astronomers discover the ‘Mighty Mouse’ of stellar remnants

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M82 Overlay

“You might think of this pulsar as the ‘Mighty Mouse’ of stellar remnants,” said Fiona Harrison of the California Institute of Technology. “It has all the power of a black hole but with much less mass.”

The discovery, made with NASA's Nuclear Spectroscopic Telescope Array (NuSTAR), is helping astronomers better understand mysterious sources of fierce X-rays, called ultraluminous X-ray sources, or ULXs. Before now, all ULXs were thought to be black holes. New data from NuSTAR show that at least one ULX, about 12 million light-years away in the galaxy Messier 82 (M82), is actually a pulsar.

“The pulsar appears to be eating the equivalent of a black hole diet,” said Harrison, NuSTAR principal investigator.

The discovery, reported in the October 9 issue of the journal Nature, will help astronomers understand how black holes gorge, and grow, so quickly – an important event in the formation of galaxies and structures in the universe.

“This is a surprising and fascinating discovery,” said Professor Andy Fabian of Cambridge’s Institute of Astronomy, one of the paper’s co-authors. “The true nature of ULXs has remained hidden since their discovery about 20 years ago and now one of them is shown to be a pulsar which is nearly 100 times brighter than it should be, according to current accretion ideas. We're all wondering how many other ULXs are similar.”

ULXs are generally thought to be black holes feeding, or accreting, off companion stars. They are suspected to be the long-sought medium-size black holes – missing links between smaller, stellar-size black holes and the gargantuan ones that dominate the hearts of all galaxies. But research into the true nature of ULXs is ongoing.

NuSTAR didn't initially set out to study the two ULXs in M82. Astronomers had been observing a recent supernova in M82, when they noticed a pulse of bright X-rays coming from a point nearby – what turned out to be the ULX called M82 X-2. Black holes don't pulse, but pulsars do.

Pulsars belong to a class of stars called neutron stars. Like black holes, neutron stars are the burnt-out cores of exploded stars, only puny in mass by comparison. Pulsars, discovered by Cambridge’s Jocelyn Bell and Antony Hewish in 1967, are neutron stars that send out beams of light. As the star spins, these beams intercept Earth like lighthouse beacons, producing a pulsed signal.

“We took it for granted that the powerful ULXs must be massive black holes,” said Matteo Bachetti, lead author of the paper from the University of Toulouse. “When we first saw the pulsations in the data, we thought they must be from another source.”

NASA's Chandra X-ray Observatory and Swift satellite had also been monitoring M82 to study the same supernova, and confirm that the intense X-rays of M82 X-2 were coming from a pulsar.

“Having a diverse array of telescopes in space means that they can help each other out,” said Paul Hertz, director of NASA's astrophysics division in Washington. “When one telescope makes a discovery, others can be called in for backup.”

The key to NuSTAR's discovery was in its sensitivity to X-rays in the highest-energy ranges as well as its ability to precisely measure the timing of the signals. This timing capability allowed the astronomers to measure a pulse rate from M82 X-2 of 1.37 seconds. They also measured its energy output at the equivalent of 10 million suns, or 10 times more than what was measured before – a big punch for something about the mass of the sun and half the size of Cambridge.

How is this puny dead star radiating so fervently? Astronomers aren't sure, but they say it is likely due to a lavish feast of the cosmic kind. As is the case with black holes, the gravity of a neutron star can pull matter off companion stars. As the matter is dragged into the neutron star, it heats up and glows with X-rays. If the pulsar is indeed feeding off surrounding matter, it is doing so at such an extreme rate to have theorists scratching their heads.

Astronomers are planning follow-up observations with NuSTAR, Swift and Chandra to help explain the bizarre behavior. The NuSTAR team will also look at more ULXs, and it's possible they could turn up more pulsars. At this point, it is not clear if the M82 X-2 is an oddball or if more ULXs beat with the pulse of dead stars. NuSTAR, a relatively small telescope, has thrown a big loop into the mystery of black holes.

Adapted from NASA press release.

An international team of astronomers has found a pulsating, dead star beaming with the energy of about 10 million suns. This is the brightest pulsar – a dense stellar remnant left over from a supernova explosion – ever recorded.

The true nature of ULXs has remained hidden since their discovery about 20 years ago
Andy Fabian
NASA/JPL-Caltech

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Yes

Price gap between more and less healthy foods grows

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A new study, published today in the journal PLOS One, tracked the price of 94 key food and beverage items from 2002 to 2012. Its findings show that more healthy foods were consistently more expensive than less healthy foods, and have risen more sharply in price over time.

Food prices in the UK have risen faster than the price of other goods in recent years, and this new research shows that the increase has been greater for more healthy foods, making them progressively more expensive over time.

While less healthy foods had a slightly greater price rise relative to 2002, the absolute increase was significantly more for more healthy foods - a total average increase of £1.84 per 1000kcal for more healthy food across the decade, compared to £0.73 for less healthy food.    

In 2002, 1000 kcal of more healthy foods – as defined by criteria devised for the UK government – cost an average of £5.65, compared to purchasing the same quantity of energy from less healthy food at £1.77. By 2012 this cost had changed to £7.49 for more healthy and £2.50 for less healthy foods.

Researchers from the Centre for Diet and Activity Research (CEDAR) at the University of Cambridge who conducted the study say that this trend could result in people increasingly turning to less healthy food.

“Food poverty and the rise of food banks have recently been an issue of public concern in the UK, but as well as making sure people don’t go hungry it is also important that a healthy diet is affordable,” said lead author Nicholas Jones.

“The increase in the price difference between more and less healthy foods is a factor that may contribute towards growing food insecurity, increasing health inequalities, and a deterioration in the health of the population.” The cost of diet-related ill health to the National Health Service has been estimated to be £5.8 billion annually.

The 94 foods and beverages in the study were taken from the Office of National Statistics’ Consumer Price Index ‘basket’: the list of items used to measure inflation in the UK. The items included in the study were those which remained in the ‘basket’ for every year of the decade analysed.

To match nationwide food prices to nutrient content for each of the foods, the researchers combined datasets from the Consumer Price Index and from the National Diet and Nutrition Survey. This novel link allowed them to establish which foods were either more or less healthy using an objective assessment of the foods’ nutrient content, as defined by the UK Food Standards Agency’s FSA-Ofcom nutrient profiling model.

“The finding shows that there could well be merit in public health bodies monitoring food prices in relation to nutrient content, hopefully taking into account a broader selection of foods than we were able to in this study,” said Nicholas Jones.

The study’s authors say their finding that more healthy food is more expensive tallies with work from similar high income nations. They point to other studies indicating that the EU’s Common Agricultural Policy - which subsidises production of certain goods such as dairy, oil and sugar - has the potential to affect public health by influencing the availability and price of foods.

“To help achieve long-term improvements in eating habits, we need to address the high and rising prices of healthier foods, which is likely to be influenced by a number of factors including agricultural policy and production, food distribution, and retail pricing strategies,” said senior author Dr Pablo Monsivais from CEDAR in Cambridge.

“Additionally, there is growing evidence that targeted subsidies can promote healthy eating for people on low incomes.”

Novel use of UK national data finds a growing gap between the prices of more and less healthy foods between 2002 and 2012. Healthy foods in 2012 were three times more expensive per calorie than less healthy foods.

We need to address the high and rising prices of healthier foods, which is likely to be influenced by a number of factors including agricultural policy and production, food distribution, and retail pricing strategies
Pablo Monsivais
Doughnut
Selected foods and price changes per 1000kcals

More healthy:                                             Less healthy:
Tinned tomatoes                                          Frozen pizza
2002 - £4.71                                               2002 - £2.10
2012 - £9.60                                               2012 - £1.58
Baked beans                                                 Ice cream
2002 - £1.05                                               2002 - £1.50
2012 - £2.05                                               2012 - £1.57
Semi-skimmed milk                                     Pork sausages
2002 - £1.07                                               2002 - £1.90
2012 - £1.73                                               2012 - £2.69

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Yes

Equality champions announced

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Professors Anne Davis (left) and Judith Lieu (right) have been appointed gender equality champions for the University.

Professor Lieu will cover gender activities for the Arts and Humanities and Social Sciences. Professor Davis will have responsibility for STEMM subjects.

They succeed the University’s former gender equality champion, Professor Dame Athene Donald, who became Master of Churchill in October.

Professor Davis says that while improvements have been made in gender equality within the University, there is still a long way to go. “There are still assumptions and attitudes and not enough women represented at all levels within the University. You cannot call yourself a top university if you only utilise the talents of a proportion of the country defined by gender,” says Davis.

Professor Lieu adds: “This is not just an issue for women – it is an issue for the University, not just because of equality legislation, but because fostering the best talent is paramount.”

Both professors say the "leaky pipe", which sees so many women leave academia as their careers develop while their male counterparts remain, must be addressed.

New equality champions have also been announced this month for schools and institutions. The roles were created in 2009 “to demonstrate senior leadership and support for equality and diversity matters and initiatives”.

University welcomes new gender equality champions

This is not just an issue for women – it is an issue for the University.
Professors Judith Lieu
The new equality champions for Schools and institutions are:
  • Dr Minna Sunikka-Blank, Professor John Rink (Arts and Humanities)
  • Professor Alison Bashford, Dr Brendan Burchell (Humanities and Social Sciences)
  • Professor Valerie Gibson, Dr Nick Bampos (Physical Sciences)
  • Professor Gordon Smith, Professor Fiona Karet (Clinical Medicine)
  • Dr Tim Minshall, Professor Sabine Bahn (Technology)
  • Professor Ottoline Leyser, Professor Daniel St Johnston (Biological Sciences)
  • Geraldine Dufour, Tim Knox (institutions independent of any School).

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Scott Polar Research Institute awarded £500,000 from Heritage Lottery Fund

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The £500,000 going to the Scott Polar Research Institute is the biggest single amount awarded to any organisation today.
 
The first Collecting Cultures awards in 2008 enabled over 2,000 objects to be bought by museums and galleries around the country. The Scott Polar Research Institute was a recipient for its Arctic Visions project. These awards give curators the opportunity to actively seek new additions to their collections rather than wait for items to come to auction.
 
Carole Souter, Chief Executive of the HLF said, “Collecting Cultures is unique: HLF is the only funding body that currently offers this type of advance funding support for museums, libraries and archives. Building on past success, a second incarnation of the initiative is back by popular demand.”
 
This money will specifically go towards By Endurance We Conquer: the Shackleton Project which will unite the Scott Polar Research Institute's Archive, Museum and Picture Library in a targeted purchasing strategy designed to develop its collection of material relating to Sir Ernest Shackleton. It will strengthen all three departments through knowledge-sharing and collaborative planning, and dramatically enhance the public engagement offerings through new acquisitions and interpretation.
 
As a result of the enormous increase in public interest generated by the centenary celebrations of Shackleton's Imperial Trans-Antarctic (Endurance) Expedition (1914-17) it is likely a large number of items relating to Shackleton's life and expeditions will either return to the market from private collections or become available for the first time. By Endurance We Conquer will enable the Scott Polar Research Institute to seize this opportunity.
 
The Institute’s Archive, The Polar Museum and the Picture Library already hold a number of Shackleton-related objects including diaries, lecture notes and poetry, foodstuffs from all four of Shackleton’s Antarctic expeditions, goggles, medals and a clock.
 
The project will examine in detail the heritage aspects of the three expeditions which Shackleton led to the Antarctic: the British Antarctic (Nimrod) Expedition (1907-09), The Imperial Trans-Antarctic (Endurance) Expedition (1914-17) and the Shackleton-Rowett (Quest) Expedition (1921-22), during which Shackleton died; in addition, the Scott Polar Research Institute’s Archive, Museum and Picture Library will seek to expand its stock of material concerning Shackleton's life outside of his major expeditions, including his family life and his involvement in Captain Robert Falcon Scott's British Antarctic (Discovery) Expedition (1901-04).
 
Sir Ernest Shackleton’s name is associated with exemplary leadership, courage in the face of adversity and the refusal to give up. He is not only of national significance; Shackleton is internationally revered as an inspiring figure and this significant HLF grant will aid research into the surviving artefacts from Shackleton’s time as one of Britain’s greatest explorers.
 
Heather Lane, Librarian and Keeper of Collections at the Scott Polar Research Institute, who led the bid, says, “We are delighted to have been awarded a £500,000 grant in the 2014 round of the Heritage Lottery Fund’s Collecting Cultures strand, and particularly honoured to be the only organisation nationally to achieve this award at the maximum level. The HLF have been most generous in their support of the redevelopment of The Polar Museum and Archives and we look forward to working with them to bring the amazing story of Sir Ernest Shackleton to wider public attention. This grant will help us to develop our collections, but most importantly will give us the means to make them truly accessible.”

 

Through its Collecting Cultures programme, the Heritage Lottery Fund (HLF) has announced a £5 million funding package which will benefit 23 museums, libraries and archives across the UK, including the Scott Polar Research Institute at the University of Cambridge.

This grant will help us to develop our collections, but most importantly will give us the means to make them truly accessible.
Heather Lane
Studio portrait of Sir Ernest Shackleton in sledging gear

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Yes

Hybrid materials could smash the solar efficiency ceiling

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Researchers have developed a new method for harvesting the energy carried by particles known as ‘dark’ spin-triplet excitons with close to 100% efficiency, clearing the way for hybrid solar cells which could far surpass current efficiency limits.

The team, from the University of Cambridge, have successfully harvested the energy of triplet excitons, an excited electron state whose energy in harvested in solar cells, and transferred it from organic to inorganic semiconductors. To date, this type of energy transfer had only been shown for spin-singlet excitons. The results are published in the journal Nature Materials.

In the natural world, excitons are a key part of photosynthesis: light photons are absorbed by pigments and generate excitons, which then carry the associated energy throughout the plant. The same process is at work in a solar cell.

In conventional semiconductors such as silicon, when one photon is absorbed it leads to the formation of one free electron that can be extracted as current. However, in pentacene, a type of organic semiconductor, the absorption of a photon leads to the formation of two electrons. But these electrons are not free and they are difficult to pin down, as they are bound up within ‘dark’ triplet exciton states.

Excitons come in two ‘flavours’: spin-singlet and spin-triplet. Spin-singlet excitons are ‘bright’ and their energy is relatively straightforward to harvest in solar cells. Triplet-spin excitons, in contrast, are ‘dark’, and the way in which the electrons spin makes it difficult to harvest the energy they carry.

“The key to making a better solar cell is to be able to extract the electrons from these dark triplet excitons,” said Maxim Tabachnyk of the University’s Cavendish Laboratory, the paper’s lead author. “If we can combine materials like pentacene with conventional semiconductors like silicon, it would allow us to break through the fundamental ceiling on the efficiency of solar cells.”

Using state-of-art femtosecond laser spectroscopy techniques, the team discovered that triplet excitons could be transferred directly into inorganic semiconductors, with a transfer efficiency of more than 95%. Once transferred to the inorganic material, the electrons from the triplets can be easily extracted.

“Combining the advantages of organic semiconductors, which are low cost and easily processable, with highly efficient inorganic semiconductors, could enable us to further push the efficiency of inorganic solar cells, like those made of silicon,” said Dr Akshay Rao, who lead the team behind the work.

The team is now investigating how the discovered energy transfer of spin-triplet excitons can be extended to other organic/inorganic systems and are developing a cheap organic coating that could be used to boost the power conversion efficiency of silicon solar cells. 

The work at Cambridge forms part of a broader initiative to harness high tech knowledge in the physical sciences to tackle global challenges such as climate change and renewable energy. This initiative is backed by the UK Engineering and Physical Sciences Research Council (EPSRC) and the Winton Programme for the Physics of Sustainability.

A new method for transferring energy from organic to inorganic semiconductors could boost the efficiency of widely used inorganic solar cells.

The key to making a better solar cell is to be able to extract the electrons from these dark triplet excitons
Maxim Tabachnyk
When light is absorbed in pentacene, the generated singlet excitons rapidly undergo fission into paris of triplets that can be efficiently transfered onto inorganic nanocrystals.

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Yes

Understanding the bushmeat market: why do people risk infection from bat meat?

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Straw coloured fruit bat

The Straw-Coloured Fruit Bat, Eidolon helvum, is widely hunted and eaten in Ghana, but carries a risk of infection with ‘zoonotic’ pathogens – diseases transmitted from animal to man. Hunting, butchering and consuming wild animals for food can potentially transmit these infections through bites, scratches, bodily fluids, tissue and excrement. Bats in particular appear to host more zoonotic viruses per species than any other group of mammals, yet very little is known about how humans and bats interact, how people perceive bats and their accompanying disease risk, or who is most at risk.

Dr Olivier Restif from the Department of Veterinary Medicine at the University of Cambridge explains: “Knowing who eats bush meat and why, as well as how they perceive the risks, is important for informing both disease and conservation management plans. This requires a close-knit collaboration between epidemiologists, ecologists and social anthropologists. That is why we have teamed up with the Zoological Society of London and the University of Ghana to develop this research programme.”

Dr Alexandra Kamins, a Gates Cambridge scholar alumna working with Dr Restif, adds: “All too often, local community voices go unheard, despite representing those most at risk of spillover and often shouldering negative impacts arising from intervention measures. That is why it was important for us to listen to them.”

Dr Kamins and colleagues interviewed 577 people across southern Ghana, including hunters, vendors and consumers of bat meat. Of these, the majority (551) were interviewed using a general survey whilst the rest were interviewed in-depth through focus groups.

The researchers found that hunters used a variety of means to capture bats, including shooting, netting and scavenging, and that all of the hunters reported handling live bats, coming into contact with bat blood and getting scratched or bitten. None of the hunters reported using protective measures, such as gloves. Scavenged bats were collected alive, usually when a branch broke and bats fell to the ground, but this too carried risks: four interviewees explained how people would fight over the bats when a large branch fell, sometimes even lying down on top of bats to prevent others from taking them, often sustaining bites and scratches.

The bats were prepared and cooked in a number of ways, the most common methods being to smoke the bats before preparing food and using the bats in soup. At odds with reports from other countries, the survey in South East Ghana revealed few uses of bat bushmeat associated with traditional beliefs or medical practices. In Ghana, bat bushmeat seems to function as both subsistence and luxury food. The large number of hunters who hunt for themselves or who keep some of their catch suggests that bats provide a readily available source of animal protein. At the same time, high taste ratings among consumers and relatively high prices suggest that bat meat is seen as a ‘luxury food’ in Ghana.

Hunters, vendors and consumers of bat meat all tended to be older than those people with no connection to the practice - on average seven to ten years older. The researchers believe this could imply a number of scenarios, the most likely being a decrease in youth interest in bat bushmeat.

They found a strong association between gender and roles in the bat-bushmeat commodity chain, with hunters primarily being male and vendors female, consistent with the cultural norms of rural Ghanaian society. This could mean that disease risk was also different between the sexes. The researchers also found that those people living in urban environments and those who were more educated were less likely to participate in bat bushmeat activities. Although this suggests that increased urbanisation and improvements in education could reduce the use of bats as bushmeat, it is possible that increased household income could lead to increased bushmeat consumption, particularly as the meat appears to be seen as a luxury item.

Using focus groups, the researchers carried out more in-depth interviews to understand participants’ likely reactions to interventions regarding bat bushmeat. They found that regulations by themselves are not effective solutions: laws and fines alone are unlikely to induce change. While only some of our respondents would be willing to risk paying fines if they continued to earn enough from selling bat bushmeat, essentially no one knew of the existing hunting laws in Ghana, suggesting that enforcement is a major issue.

Possible health risks appeared to be more of a deterrent than fines; some respondents suggested that disease risk could motivate them to stop. However, the risk of disease from bat bushmeat was considered to be greatest by those who did not consume the meat and lowest by those who hunted or sold the bats. This finding supports previous research suggesting that people can readily perceive risk and even intellectually acknowledge desire to reduce that risk, but actual behaviour might not change.

Professor James Wood, who leads the research programme at the University of Cambridge, says: “Understanding both actual and perceived risk factors is vital. If a bat-borne zoonotic disease outbreak were to occur in Ghana, our information could prove invaluable in helping target those groups at greatest risk and in planning disease control measures.”

Dr Marcus Rowcliffe from ZSL adds: “Unfortunately, there may not be a simple way to minimise the risks of zoonotic spillover from bats. For example, bat hunting is a highly seasonal occupation and, like all bushmeat hunting, can be started and dropped at will, whereas rearing domestic animals – one possible sustainable solution for reducing bushmeat hunting – requires continuous activity throughout the year on a daily basis.

“Although many programmes suggest economic opportunity as the major motivation behind livelihood choices and success of alternatives, it may not be enough on its own. We found people in Ghana to be responsive to education pieces about the disease risk from bushmeat but also the ecological role of bats in pollination and seed dispersal. Working with local communities to help them find effective and sustainable solutions in line with their economic needs must be a long-term commitment.”

Reference
Kamins, AO et al. Characteristics and Risk Perceptions of Ghanaians Potentially Exposed to Bat-Borne Zoonoses through Bushmeat. Ecohealth; 30 Sept 2014

Ebola, as with many emerging infections, is likely to have arisen due to man’s interaction with wild animals – most likely the practice of hunting and eating wild meat known as ‘bushmeat’. A team of researchers led by the University of Cambridge and the Zoological Society of London (ZSL) has surveyed almost six hundred people across southern Ghana to find out what drives consumption of bat bushmeat – and how people perceive the risks associated with the practice.

Knowing who eats bush meat and why, as well as how they perceive the risks, is important for informing both disease and conservation management plans
Olivier Restif
Straw coloured fruit bat (edit)

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Yes
License type: 

Mapping the weather on WASP-43b

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A team of scientists, including astronomers from the University of Cambridge, have made the most detailed map ever of the temperature of an exoplanet’s atmosphere, and traced the amount of water it contains. The planet targeted for both of the investigations was the hot-Jupiter exoplanet WASP-43b, which is about 261 light years away in the Sextans constellation.

WASP-43b is a planet the size of Jupiter, but with double the mass and an orbit much closer to its parent star than any planet in the Solar System. It has one of the shortest years ever measured for an exoplanet of its size — lasting just 19 hours.

A team of astronomers working on two companion studies have now created detailed weather maps of WASP-43b, using data from the NASA/ESA Hubble Space Telescope. One study mapped the temperature at different layers in the planet’s atmosphere, and the other traced the amount and distribution of water vapour within it — detail is shown in the video created by the team.

“Our observations are the first of their kind in terms of providing a two-dimensional map of the planet’s thermal structure,” said Kevin Stevenson from the University of Chicago, lead author of the thermal map study. “These maps can be used to constrain circulation models that predict how heat is transported from an exoplanet's hot day side to its cool night side.”

The planet has different sides for day and night because it is tidally locked, meaning that it keeps one hemisphere facing the star, just as the Moon keeps one face toward Earth. The Hubble observations show that the exoplanet has winds that howl at the speed of sound from a day side that is hot enough to melt iron — soaring above 1500 degrees Celsius — to the pitch-black night side that sees temperatures plunge to a comparatively cool 500 degrees Celsius.

To study the atmosphere of WASP-43b the team combined two previous methods of analysing exoplanets for the first time.

By looking at how the parent star’s light filtered through the planet’s atmosphere — a technique called transmission spectroscopy — they determined the water abundance of the atmosphere on the boundary between the day and night hemispheres.

In order to make the map more detailed the team also measured the water abundances and temperatures at different longitudes. To do this they took advantage of the precision and stability of Hubble’s instruments to subtract more than 99.95% of the light from the parent star, allowing them to study the light coming from the planet itself — a technique called emission spectroscopy. By doing this at different points of the planet’s orbit around the parent star they could map the atmosphere across its longitude.

“We have been able to observe three complete rotations — three years for this distant planet — during a span of just four days,” explained Jacob Bean from the University of Chicago, leader of the research project. “This was essential in allowing us to create the first full temperature map for an exoplanet and to probe its atmosphere to find out which elements it held and where.”
Finding the proportions of the different elements in planetary atmospheres provides vital clues to understanding how planets formed.

“Because there’s no planet with these tortured conditions in the Solar System, characterising the atmosphere of such a bizarre world provides a unique laboratory with which to acquire a better understanding of planet formation and planetary physics,” said Nikku Madhusudhan of Cambridge’s Institute of Astronomy, co-author of both studies. “In this case the discovery fits well with pre-existing models of how such planets behave.”

The team found that WASP-43b reflected very little of its host star’s light. An atmosphere like that on Earth, with clouds that reflect most of the sunlight, is not present on WASP-43b, but the team did find water vapour in the planet’s atmosphere.

“The planet is so hot that all the water in its atmosphere is vapourised, rather than condensed into the icy clouds we find on Jupiter,” said team member Laura Kreidberg of the University of Chicago, lead author of the study mapping water on the planet.

Water is thought to play an important role in the formation of giant planets. Astronomers theorise that comet-like bodies bombard young planets, delivering most of the water and other molecules that we observe. However, the water abundances in the giant planets of the Solar System are poorly known because water is locked away as ice, deep in their atmospheres which makes it difficult to identify.

“Space probes have not been able to penetrate deep enough into Jupiter’s atmosphere to obtain a clear measurement of its water abundance. But this giant planet is different,” added Derek Homeier of the École Normale Supérieure de Lyon, co-author of the studies. “WASP-43b’s water is in the form of a vapour that can be much more easily traced. So we could not only find it, we were able to directly measure how much there is and test for variations along the planet’s longitude.”

In WASP-43b the team found the same amount of water as we would expect for an object with the same chemical composition as the Sun.

“This tells us something fundamental about how the planet formed,” added Kreidberg.“Next, we aim to make water-abundance measurements for different planets to explore their chemical abundances and learn more about how planets of different sizes and types come to form around our own Sun and the stars beyond it.”

The results are presented in two new papers, one on the thermal mapping of the planet’s atmosphere — published online in Science Express on 9 October — and the other on mapping the water content of the atmosphere — published in The Astrophysical Journal Letters on 12 September.

Adapted from European Space Agency press release.

Two new studies have been used to make the most detailed weather map for a planet outside the solar system, where typical daytime highs reach 1500 degrees Celsius and winds exceed the speed of sound.

The atmosphere of such a bizarre world provides a unique laboratory with which to acquire a better understanding of planet formation and planetary physics
Nikku Madhusudhan
Exoplanet WASP-43b orbits its parent star

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Yes

Spin with a new twist

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A new method of controlling the “spin” of an electron, one of the fastest-developing research topics in quantum-based technologies and widely seen as the potential foundation of numerous future advances, has been demonstrated by scientists.

In quantum physics, the “spin” of a particle refers to its intrinsic angular momentum. This can be controlled so that it is aligned with one of two directions, typically referred to as “up” or “down”.

Usually, researchers define the direction by applying a magnetic field to orientate the electron, called the “quantisation axis”. The process can, however, be distorted by the natural magnetic environment around the electron itself, which is usually seen as one of the biggest obstacles to controlling spin.

Uniquely, the new study, by a team at the University of Cambridge and the Joint Quantum Institute (JQI) in the USA, instead turned this magnetic field into a natural advantage which allowed the electron to be held in place. The researchers did this by firing two precisely-tuned lasers at the particle, creating what they call a “dark state” from which it could be manipulated and measured.

The implications for controlling quantum systems are significant because, since the 1990s, researchers have theorised that a particle’s spin could be used to store and manipulate information. Using the “up” or “down” as an alternative to the binary coding of 0s and 1s that characterises computers today, spin-based quantum computers would be able to compute difficult problems and vast amounts of data much more efficiently.

Any such development, however, depends on finding ways to bring electron spin under control in the first place. To date, researchers have had to find ways to do this in spite of the randomising effect that the magnetic field around an electron has on the orientation of its spin.

The spin of an electron cannot be observed continuously without altering it, so it has to be measured before and after an attempt to manipulate its quantum state. This measurement reveals whether the spin is up or down, but the surrounding magnetic environment can also take effect at any time. If it does so, the quantisation axis of the electron is altered, and the whole picture is distorted. The effect is similar to trying to measure longitude and latitude in a world where the positions of the north and south poles are changing randomly all the time.

Dr Mete Atatüre, a researcher at St John’s College, Cambridge who led part of the new study, said: “In order to perform reliable measurements, we constantly have to fight against this fluctuating magnetic environment. In fact, most research is about trying to keep electrons detached or isolated from it. What is unique about this experiment is that we did the opposite and used this environment as a resource. We created a quantum state that wouldn’t be accessible if the magnetic field wasn’t there.”

The electron was trapped inside a self-assembled “quantum dot”, a tiny structure made from a 10 nanometre-thick indium arsenide droplet, surrounded by gallium arsenide. While both materials are semiconductors, an electron can have a lower energy inside the “quantum dot” than in gallium arsenide. “This forms a natural and stable trap for single electrons within a semiconductor device, providing the desired conditions for defining a spin quantum bit” explained Carsten Schulte, a Cambridge graduate student who worked on the project.

An electron isolated in this fashion can then be targeted with lasers to manipulate its spin. If a laser strikes the quantum dot at certain wavelengths, the electron is optically excited and emits light, or fluoresces, which changes its spin. If, however, the magnetic environment interferes with this the change becomes uncontrollable.

To resolve this, the researchers fired two separate lasers at the quantum dot – one tuned to excite the “up” spin state, the other to excite the “down” state. These interfered with each other destructively, preventing any fluorescence at all and creating a so-called “dark state”.

“You would expect two lasers to raise the level of optical excitation even more, but in fact when this is done no light comes out of the quantum dot,” Jack Hansom, another graduate student in the research team, said. “Optical excitation ceases and the electron finds a unique quantum superposition state, which is neither up nor down.”

By changing the relative phase between the two lasers, they were able to redefine the specific dark state and force the electron into it. This showed that the electron could be manipulated in its own up/down coordinate system without the researchers ever knowing the orientation of up and down during the whole process.

“What is profound is that the electron is always in the same quantum superposition state, but the basis in which it is represented evolves with the nuclear field that remains unknown to us,” Atatüre added. “This research shows that the magnetic environment around the quantum dot does not need to remain a problem, but can be utilized for the definition and control of a quantum bit.”

The full report appears in the October issue of Nature Physics.

Scientists have successfully demonstrated a new way to control the “spin” of an electron – the natural intrinsic angular momentum of electrons which could underpin faster computing in the future. The technique counterintuitively makes use of the ever-changing magnetic field of the electron’s environment - one of the main obstacles to traditional methods of spin control.

Most research is about trying to keep electrons isolated from the magnetic environment. What is unique about this experiment is that we did the opposite and used it as a resource
Mete Atature
Spin manipulation in a noisy environment. In the quest for ever more precise manipulation of quantum systems, any uncontrolled interaction with the environment is usually considered detrimental.

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Yes

Obsessive-compulsive disorder - does age matter?

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Have you locked the door this morning? Are you sure? If you feel the need to go back and check now, you are experiencing some of the key problems of obsessive-compulsive disorder (OCD): doubt, uncertainty and worry.

The difference between you and a person diagnosed with OCD is that you will check the door once. Afterwards, you will continue with your day, satisfied and calm. Yet, despite having checked 20, 30, or more times, an OCD patient may remain deeply unsettled. Believing for example, that his parents will die unless the door is locked properly, he can't stop until it "feels just right".

We all obsess about things every now and then, but usually our worries serve a purpose. Not giving burglars a chance, for instance. Obsessions and compulsions in OCD, however, are irrational. They dominate patients' lives, cause distress and make many of them unable to study or work. Therefore, OCD is not just a personal issue; it is also an economic problem for society. Treatments are available, but they only work for about half of the patients. If we are to develop more effective therapies, we will first have to gain a deeper understanding of the disorder itself.

My PhD project focuses on how OCD starts in the first place. More than 80% of the patients experience their first symptoms before the age of 18. However, most of the research has focused on OCD in adults. This group is usually asked to complete a few computer based tasks. Designed as puzzles or games, the tasks keep participants interested whilst producing important data that give us an insight into their abilities.

Researchers all over the world have identified key functions that are less developed in OCD. Suppressing a hand movement that has already started is one of them. If you were a participant in such a study, you would be asked to respond to an on-screen arrow by pressing a button as quickly as possible. However, when the arrow is followed by a "beep" you should not respond at all. While this sounds easy enough at first, the beep is delayed until you can't help pressing the button incorrectly. Afterwards, we can measure how much time between the appearance of the arrow and the "beep" you needed to reliably stop your hand movement. For OCD patients, this time is shorter than for healthy people. They are what we call "disinhibited", which might explain their difficulties with control in general.

Next, we will ask you to play another game. You see two patterns and must determine which one is 'correct'. After a few attempts you may spot a rule that allows you to succeed every time, but again, there is a surprise in store. Each time you learn the rule, the computer will change it, making it a little more difficult. Beginning as just purple shapes, the patterns become more complex as white lines are added. While irrelevant in the beginning, eventually you will need to learn a rule about these lines.

Healthy people are quite able to forget the old rules and to learn the new ones. However, OCD patients find it particularly hard to focus on the lines which they could previously ignore. They are stuck with the old solution to the problem and can't unlearn it. It might be the same kind of inflexibility in their every-day lives that requires them to check a door an excessive number of times to be sure it is locked… if they ever are sure.

There is a big controversy about whether adolescent and adult OCD are part of the same disease, or if they should be seen as two separate subgroups. The OCD symptoms reported in children and adults are similar and we treat them in almost identical ways: behavioural therapy and medication. Nonetheless, there are more male than female adolescent OCD patients, whereas there is a gender balance amongst adult sufferers. Moreover, while many patients of all ages have other issues in addition to OCD, it tends to be ADHD in teenagers, but depression in adults. This raises the question: are there fundamental differences between these two groups in terms of the OCD itself? Or do the adolescent patients grow up and still have the same less developed functions?

To test this, I will give the games you played in the fictional psychology lab to teenagers with OCD. If they are as disinhibited and inflexible as their adult counterparts, this suggests teen and adult OCD is the same mental disorder. If not, we might have to re-think our ways of treating adolescents with OCD and develop new therapies. Either way, we will understand how OCD starts in young people and what the key functions are that patients lack.

Max Perutz Science Writing Award

Inset image: Julia Gottwald

The Max Perutz Science Writing Award aims to encourage and recognise outstanding written communication among MRC PhD students. The annual competition challenges entrants to write an 800-word article for the general public answering the question: 'Why does my research matter?'. This year, Julia Gottwald, a PhD student in the Department of Psychiatry, was shortlisted for her article about obsessive compulsive disorder.

Person washing hands (cropped image)

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Yes

Stem cell physical

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One of the many mysteries surrounding stem cells is how the constantly regenerating cells in adults, such as those in skin, are able to achieve the delicate balance between self-renewal and differentiation – in other words, both maintaining their numbers and producing cells that are more specialised to replace those that are used up or damaged.

“What all of us want to understand is how stem cells decide to make and maintain a body plan,” said Dr Kevin Chalut, a Cambridge physicist who moved his lab to the University’s Wellcome Trust-MRC Cambridge Stem Cell Institute two years ago. “How do they decide whether they’re going to differentiate or stay a stem cell in order to replenish tissue? We have discovered a lot about stem cells, but at this point nobody can tell you exactly how they maintain that balance.”

To unravel this mystery, both Chalut and another physicist, Professor Ben Simons, are bringing a fresh perspective to the biologists’ work. Looking at problems through the lens of a physicist helps them untangle many of the complex datasets associated with stem cell research. It also, they say, makes them unafraid to ask questions that some biologists might consider ‘heretical’, such as whether a few simple rules describe stem cells. “As physicists, we’re very used to the idea that complex systems have emergent behaviour that may be described by simple rules,” explained Simons.

What they have discovered is challenging some of the basic assumptions we have about stem cells.

One of those assumptions is that once a stem cell has been ‘fated’ for differentiation, there’s no going back. “In fact, it appears that stem cells are much more adaptable than previously thought,” said Simons.
By using fluorescent markers and live imaging to track a stem cell’s progression, Simons’ group has found that they can move backwards and forwards between states biased towards renewal and differentiation, depending on their physical position in the their host environment, known as the stem cell niche.

For example, some have argued that mammals, from elephants to mice, require just a few hundred blood stem cells to maintain sufficient levels of blood in the body. “Which sounds crazy,” said Simons. “But if the self-renewal potential of cells may vary reversibly, the number of cells that retain stem cell potential may be much higher. Just because a certain cell may have a low chance of self-renewal today doesn’t mean that it will still be low tomorrow or next week!”

Chalut’s group is also looking at the way in which stem cells interact with their environment, specifically at the role that their physical and mechanical properties might play in how they make their fate decisions. It’s a little-studied area, but one that could play a key role in understanding how stem cells work.
“If you go to the grocery store to buy an avocado, you’re not going to perform lots of chemistry on it in order to decide which is the best one: you’re going to pick it up and squeeze it,” said Chalut. “In essence, this is what we’re trying to do with stem cells.”

Chalut’s team is looking at the exact point where pluripotency – the ability to generate any other cell type in the body – arises in the embryo, and determining what role physical or mechanical signals play in generating this ‘ultimate’ stem cell state.

Using fluid pressure to squeeze the stem cells through a channel, as well as miniature cantilevers to push down on the cells, the researchers were able to observe and measure the mechanical properties of these master cells.

What they found is that the nuclei of embryonic stem cells display a bizarre and highly unusual property known as auxeticity. Most materials will contract when stretched. If you pull on an elastic band, the elastic will get thinner. If you squeeze a tennis ball, its circumference  will get larger. However, auxetic materials react differently – squeeze them and they contract, stretch them and they expand.

“The nucleus of an embryonic stem cell is an auxetic sponge – it can open up and soak up material when it’s pulled on and expel all that material when it’s compressed,” said Chalut. “But once the cells have differentiated, this property goes away.”

Auxeticity arises precisely at the point in a stem cell’s development that it needs to start differentiating, so it’s possible that the property exists so that the nucleus is able to allow entrance and space to the molecules required for differentiation.

“There’s a lot of discussion about what exactly it means to be pluripotent, and how pluripotency is regulated,” said Chalut. “Many different factors play a role, but we believe one of those factors may be a mechanical signal. This may also be the case in the developing embryo.”

By bringing together physics and biology, Simons and Chalut believe not only that some of the defining questions in embryonic and adult stem cell biology can be addressed, but also that new insights can be found into mechanisms of dysregulation in disease, cancer and ageing.

“One of the reasons that this bringing together of disciplines sometimes doesn’t work so well is that physicists don’t want to understand the biology and biologists don’t want to understand the physics,” said Chalut. “In a sense, biologists don’t know the physical questions to ask, and physicists don’t know the biological questions to ask. As a physicist, the main reason I wanted to move my lab to the Stem Cell Institute is I thought there was no point working in biology if I didn’t understand which questions to ask.”

“There’s a real effort being made to combine biology and physics much more than they have been in the past,” added Simons. “It takes a bit of a leap of faith to believe physics will enrich the field of biology, but I think it’s a very reasonable leap of faith. Scientific history is full of fields that have been enriched by people coming in and looking at an issue from different directions.”

Inset image: Kevin Chalut (left) and Ben Simons.

Looking at stem cells through physicists’ eyes is challenging some of our basic assumptions about the body’s master cells.

What all of us want to understand is how stem cells decide to make and maintain a body plan
Kevin Chalut
Stem cells show auxeticity; the nucleus expands, rather than thins, when it's stretched

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