Articles on this Page
- 10/11/16--04:00: _Diagnosis of cancer...
- 10/11/16--11:00: _New approach to tre...
- 10/12/16--04:40: _Cambridge's postgra...
- 10/12/16--04:01: _The Whistle: verify...
- 10/12/16--16:33: _Fruit fly model of ...
- 10/13/16--01:05: _Lost in high-dimens...
- 10/13/16--05:00: _Opinion: Brexit and...
- 10/14/16--01:10: _Opinion: Pirate, tu...
- 10/14/16--01:43: _Internet censorship...
- 10/17/16--02:19: _Cambridge Festival ...
- 10/17/16--04:39: _Brexit week
- 10/17/16--05:02: _Could cryptocurrenc...
- 10/17/16--08:00: _ Researchers road-t...
- 10/18/16--00:57: _Anti-inflammatory d...
- 10/19/16--00:00: _Opinion: Brexit and...
- 10/19/16--01:36: _“Oldest club in the...
- 10/19/16--05:47: _Opinion: New findin...
- 10/19/16--07:58: _“The best or worst ...
- 10/20/16--07:17: _Artificial intellig...
- 10/20/16--11:00: _Engineers design ul...
- 10/12/16--04:40: Cambridge's postgraduate pioneers
- 10/12/16--04:01: The Whistle: verifying digital evidence of human rights violations
- 10/13/16--05:00: Opinion: Brexit and the importance of languages for Britain #3
- 10/14/16--01:43: Internet censorship: making the hidden visible
- 10/17/16--02:19: Cambridge Festival of Ideas kicks off
- Re/Collections: Libraries in the 21st century - a panel of experts will debate the changing role of libraries [26th October]. The event is part of the celebrations for the 600th anniversary of Cambridge University Library. Author Ali Smith will kick off the debate by presenting a newly commissioned piece written especially for the event.
- Smartfiction: Literature On Your Phone - award-winning author Kate Pullinger will talk about writing for the smartphone. She is currently working on a serialised multimedia novel for smartphones.[28th October].
- Should women breastfeed each other's babies? - a panel including historians, a sociologist and a neonatal expert will look at historic precedents as well as health and practical considerations today and ask whether we can learn something from the past about infant feeding. [26th October]
- Human trafficking: transnational partnerships Experts from across Europe will debate how countries can work together to stem the trafficking of human beings across the continent in this high-profile panel discussion. With Director of Europol Rob Wainwright; Andrew Boff, author of Shadow City – Exposing Human Trafficking in Everyday London; Philip Ishola, Former Director of the Counter Human Trafficking Bureau; and Fiona Hill, Joint Downing Street Chief of Staff, lead author of the Modern Slavery Act 2015 and author of A Modern Response to Modern Slavery Report. [22nd October]
- Universities and free speech [21st October] According to recent research about 80% of universities have restrictions on free speech. What does free speech imply in the context of a University? Is it all about academic freedom or might it have something to do with protecting the status quo? Speakers include writer and academic Malachi McIntosh, writer and academic Joanna Williams, Professor Steve Fuller and Priscilla Mensah, President of the Cambridge Students’ Union.
- 10/17/16--04:39: Brexit week
- Chair: Professor Catherine Barnard, Professor of European Union Law and Employment Law, Faculty of Law.
- Dr Victoria Bateman, Director of Studies, Fellow and College Lecturer in Economics at Gonville & Caius College, Cambridge.
- Dr Chris Bickerton, University Lecturer in Politics at POLIS and Official Fellow at Queens’ College, Cambridge.
- Professor Robert Tombs, Professor of Modern European History, Faculty of History and Fellow at St John’s College, Cambridge.
- Chair: Dr Albertina Albors-Llorens, Reader in European Union Law, Faculty of Law, Cambridge.
- Professor Coen Teulings, Montague Burton Chair of Labour Economics and Industrial Relations, Faculty of Economics, Cambridge.
- Charles Clarke, former Home Secretary.
- Professor Athene Donald, Professor of Experimental Physics, Cavendish Laboratory and Master, Churchill College.
- Chair: Dr Alicia Hinarejos, Senior Lecturer, Faculty of Law, Cambridge.
- Professor David Runciman, Professor of Politics and Head of Department at POLIS and Fellow at Trinity Hall, Cambridge.
- Professor Mark Elliott, Professor of Public Law, Faculty of Law, and Fellow, St Catharine's College, Cambridge.
- Professor Catherine Barnard, Professor of European Union Law and Employment Law, Faculty of Law, Fellow and Senior Tutor, Trinity College, Cambridge, Senior Fellow of UK in a Changing Europe.
- Chair: Chris Mann, BBC.
- Professor Catherine Barnard, Professor of European Union Law and Employment Law, Faculty of Law, Fellow and Senior Tutor, Trinity College, Cambridge, Senior Fellow of UK in a Changing Europe.
- Dr Chris Bickerton, University Lecturer in Politics at POLIS and Official Fellow at Queens’ College, Cambridge.
- Sonia Delesalle-Stolper, UK and Ireland correspondent of Libération
- Larry Elliott, economics editor, The Guardian.
- Chair: Dr Julie Smith, Senior Lecturer, Department of Politics and International Studies and Fellow, Robinson College, Cambridge.
- Professor Catherine Barnard, Professor of European Union Law and Employment Law, Faculty of Law, Fellow and Senior Tutor, Trinity College, Cambridge, Senior Fellow of UK in a Changing Europe.
- Matthew Elliott, Head of Vote Leave.
- Professor Anand Menon, Professor of European Politics and Foreign Affairs, King’s College London and Director of UK in a Changing Europe.
- Jonathan Portes, Principal Research Fellow at the National Institute of Economic and Social Research and Senior Fellow of UK in a Changing Europe.
- Chair: Chair: Andrew Wheelhouse, Senior Paralegal, Bates Wells Braithwaite LLP
- Conor Gearty, Barrister and Professor of Human Rights law, London School of Economics.
- Luke Gitos, Criminal Lawyer and Director of City of London Appeals Clinic.
- Martin Howe QC, Barrister and Chairman of Lawyers for Britain.
- Matthew Scott, Barrister at Pump Court Chambers.
- 10/17/16--05:02: Could cryptocurrency help the ‘bottom billion’?
- 10/17/16--08:00: Researchers road-test powerful method for studying singlet fission
- 10/19/16--00:00: Opinion: Brexit and the importance of languages for Britain #4
- 10/19/16--01:36: “Oldest club in the world” inducted into the Football Hall of Fame
- 10/19/16--05:47: Opinion: New findings: anxiety is linked to death from cancer in men
- 10/20/16--07:17: Artificial intelligence: computer says YES (but is it right?)
In an article in the journal Nature Reviews Clinical Oncology, a team of researchers jointly led by the University of Cambridge and University College London reviewed current evidence from 26 peer-reviewed studies and 6 online reports from 7 countries. The evidence indicates that emergency diagnosis of cancer is a universal problem, challenging previous assumptions regarding this issue being a particular problem only in the UK.
Looking at prognosis alone, the researchers reviewed evidence that showed that patients diagnosed with colorectal cancer at emergency presentation had a 50% one year survival rate, compared to 82% for patients diagnosed electively - in other words, following a GP referral to a specialist. Similarly, for lung cancer the respective survival rates were 12% versus 40%. This was in part because cancer diagnosed at emergency care was more likely to be at an advanced stage. However, this was not the full story: even when patients presented with tumours of the same disease stage they still had a worse prognosis if they were diagnosed in emergency care, possibly because of problems in the quality of their management out-of-hours, or because they have more aggressive disease on a stage-for-stage basis.
In the UK, about three in 10 emergency presenters are referred to hospital emergency services by their family doctors, but others self-present to accident and emergency departments. Patients at both ends of the age spectrum – the youngest and the oldest – were most likely to have their cancer diagnosed in emergency contexts. Differences between genders were unclear – and vary for different types of cancer.
However, the review found particular inequalities between socioeconomic groups. Although the evidence came only from studies looking at colorectal and lung cancer, it found that people from more deprived backgrounds were at a greater risk of being diagnosed at emergency care. The same was true for people of Asian ethnicity in the UK and African-Americans in the USA.
First author Dr Yin Zhou from the Primary Care Unit at the University of Cambridge, who led the study, says: "The earlier an individual can get a diagnosis of cancer, the better the prognosis and the options for treatment. When the first time their cancer is identified is when it becomes an emergency, the prognosis is much worse.”
Dr Georgios Lyratzopoulos, who instigated and coordinated the collaboration, based at the Department of Epidemiology and Public Health, University College London adds: "A substantial minority of cancer patients who are diagnosed as emergencies do not seem to have had prior contact with the formal healthcare system; we need to find out why they are not seeking medical help sooner. Is it because they are unaware of any symptoms until too late, or is it because they do not think the symptoms are a sign of a more serious problem?"
The researchers found that the evidence points towards developing new screening methods and improving participation in existing screening programme as one possible way to reduce emergency presentations in the medium to longer term. For example, based on indirect evidence in one geographical region in the UK, the introduction of faecal occult blood test in the UK is likely to have reduced the proportion of patients with colorectal cancer diagnosed as emergencies by half between 1999 and 2004.
"What was clear from our review," adds Dr Zhou, "is how little data there is available about emergency diagnoses. What little data there is suggests that we're only seeing the tip of the iceberg and that this could be a much bigger problem, particularly in low and middle income countries."
A major part of the global evidence on emergency presentations (in terms of patient numbers) relates to English patients – thanks to the pioneering Routes to Diagnosis project and population-based data collected by the National Cancer Registration and Analysis Services of Public Health England.
Dr Anne Mackie, Director of Screening at Public Health England, said: “Screening has a vital role to play in identifying cancers at an early stage and getting people the right treatment as soon as possible, with better survival chances. Screening is always the person’s own choice and they should speak to their GP if they have any questions before deciding if screening is right for them.”
Zhou, Y et al. Diagnosis of cancer as an emergency: a critical review of current evidence. Nature Reviews Clinical Oncology; 11 Oct 2016; 10.1038/nrclinonc.2016.155
Too many patients – particularly those from disadvantaged backgrounds – are being diagnosed with cancer as medical emergencies, say researchers. This means that their chances of successful treatment are greatly reduced.
Type 1 diabetes is one of the most common chronic diseases in children and there is a rapid increase in the number affected each year. About 400,000 people in the UK are affected, 29,000 of them children. In type 1 diabetes, the body’s own immune system mistakes the insulin producing cells of the pancreas as harmful, attacks and then destroys them. The result is a lack of insulin, which is essential for transporting glucose from the blood into cells. Without insulin, glucose levels in the blood rise, causing short term and long term damage: hence patients have to inject themselves several times a day with insulin to compensate.
In a study published today in the open access journal PLOS Medicine, a team led by researchers from the JDRF/Wellcome Trust Diabetes Inflammation Laboratory at the Cambridge Institute of Medical Research used a drug to regulate the immune system with the aim of preventing a patient’s immune cells attacking their insulin-producing cells in the pancreas.
The drug, aldesleukin, recombinant interleukin -2 (IL-2), is currently used at high doses to treat certain types of kidney tumours and skin cancers. At much lower doses, aldesleukin enhances the ability of immune cells called regulatory T cells (Tregs) to stop the immune system losing control once stimulated and prevent it from damaging the body’s own organs (autoimmunity).
Critical to this approach was to first determine the effects of single doses of aldesleukin on Tregs in patients with type 1 diabetes. To achieve this the team employed a state-of-the-art trial design combined with extensive immune monitoring in 40 participants with type 1 diabetes, and found doses to increase Tregs by between 10-20%. These doses are potentially enough to prevent immune cells from attacking the body, but not so much that they would supress the body’s natural defences, which are essential for protecting us from infection by invading bacteria or viruses.
The researchers also found that the absence of response of some participants in previous trials may be explained by the daily dosing regimen of aldesleukin used. The current trial results suggest that daily dosing results in Tregs becoming less sensitive to the drug, and the recommendation from the study is that the drug should not be administered on a daily basis for optimal immune outcomes.
“Type 1 diabetes is fatal if left untreated, but the current treatment – multiple daily injections of insulin – are at best inconvenient, at worst painful, particularly for children,” says Dr Frank Waldron-Lynch, who led the trial. “Our goal is to develop a treatment that could see the end to the need for these life-long, daily injections by curtailing the early damage caused by the patient’s own immune system.
“Our work is at an early stage, but it uses a drug that occurs naturally within the body to restore the immune system to health in these patients. Whereas previous approaches have focused on suppressing the immune system, we are looking to fine-tune it. Our next step is to find the optimal, ‘Goldilocks’ treatment regimen – too little and it won’t stop the damage, too much and it could impair our natural defences, but just right and it would enhance the body’s own response.”
The researchers say that any treatment would initially focus on people who are newly-diagnosed with type 1 diabetes, many of whom are still able to produce sufficient insulin to prevent complications from the disease. The treatment could then help prevent further damage and help them to continue to produce a small amount of insulin for a longer period of time.
The research was largely funded by the type 1 diabetes charity JDRF, the Wellcome Trust and the Sir Jules Thorn Charitable Trust, with support from the National Institute for Health Research (NIHR) Cambridge Biomedical Research Centre.
Angela Wipperman, Senior Research Communications Manager at JDRF, said: “Immunotherapy research offers the potential to change the lives of those affected by type 1 diabetes. We eagerly await the next steps from this talented research team.”
Todd JA, Evangelou M, Cutler AJ, Pekalski ML, Walker NM, Stevens HE, et al. PLOS Medicine; 11 Oct 2016; DOI: 10.1371/journal.pmed.1002139
Researchers at the University of Cambridge have taken the first step towards developing a new form of treatment for type 1 diabetes which, if successful, could mean an end to the regular insulin injections endured by people affected by the disease, many of whom are children.
Jonny Hanson, Department of Geography
Postgraduate students at Cambridge walk in the footsteps of giants – Francis Crick, Elizabeth Blackburn, Stephen Hawking, Iris Murdoch and Eric Hobsbawm all pursued PhD research at the University.
The footage is shaky but the sounds of gunfire and “Allahu Akbar!” are unmistakable as the boy darts along the dusty road towards the burnt-out car. Puffs of smoke erupt around him. He falls to his knees. Has he been shot? It’s hard to tell, but a moment later he is up again, running for the shelter of the abandoned car. Yet it’s not over. He emerges holding the hand of an even younger girl dressed in pink. They run, hesitantly at first, then desperately. The fear on their faces is palpable.
This is the ‘Syrian Hero Boy’. The footage appeared on 10 November 2014 on YouTube and it quickly went viral as millions of viewers watched, astonished at the boy’s bravery and shocked at a world that could place children in such danger.
But further shock was to come. The film was fake. It was filmed in Malta on the set of Gladiator by Norwegian film-maker Lars Klevberg.
Klevberg’s intention was to spur debate about children and war. By pretending the film was real, he believed that “people would share it and react with hope.”
It also drew attention to an increasingly common scenario: fake footage appearing on social media. “By publishing a clip that could appear to be authentic, we hoped to take advantage of a tool that’s often used in war; make a video that claims to be real,” he said.
In our digitally enabled world, a legion of ‘civilian witnesses’ has sprung up: individuals “in the wrong place at the wrong time” who capture an event and then publish the scrap of footage or the incriminating photograph on social media. But amid the fog of propaganda, hoaxes and digital manipulation, how can we tell what’s real and what’s fake?
Cambridge researchers are developing an automated tool, ‘the Whistle’, to help verify the authenticity of digital evidence.
Behind the Whistle is sociologist Dr Ella McPherson: “There is much excitement about the speed with which news can be captured by bystanders and disseminated on social media. In the field of human rights, it allows fact-finders for NGOs to get digital reports of violations from hard-to-reach places.
“In a country such as Syria, which is largely closed to outside observers, YouTube videos are a crucial source of information for people within and without its borders and contribute to an information environment incomparable to the past.”
She mentions footage that appeared on social media in 2013 which Syrian opposition activists claimed as being evidence of a chemical weapons attack. An expert told the BBC that the footage was consistent with such an attack, although he cautioned that it was difficult to verify the film owing to the absence of metadata. Meanwhile the state-run news agency Sana said the claims were “baseless” and an attempt to distract United Nations weapons inspectors.
“This example shows the nature of the terrain we are now in: news is disseminated fast but verification is slow and often contested,” says McPherson. “For human rights NGOs, credibility can be lost in a moment if the evidence they are using for advocacy or in courts is later found to be false. No matter how devastating the documented violations, they cannot act on them unless they can verify them first.”
Many guidelines, handbooks and tools now exist to help the verification process. The ‘witness’ can be checked through their digital footprint – their organisational affiliations or a social media profile, for instance. The image itself can be corroborated through comparison with landmarks and weather data, or checked using tools that ‘reverse image search’ for previous publication.
However, all of this takes precious time, which may introduce bias – those who are easier to verify may be more likely to be heard than those who have few resources and a minimal digital footprint.
Through her research interests in how social media can be used by human rights NGOs for generating governmental accountability, McPherson became increasingly aware that fact-finders were struggling with the torrent of information. Time spent verifying was in danger of crippling this most powerful means of communication. For Syria, fact-finders have described the number of videos and photos as becoming a ‘Big Data’ problem.
The Whistle is a digital platform that speeds up the whole process. Being developed for mobile and web, the app eases the process of reporting for the witness, and prompts them to furnish the information needed by the fact-finder for verification – the “who, what, why, where, when” metadata. A ‘dashboard’ then aggregates the information and automates the cross-checking process of comparing the civilian witness report to the many databases that are used to corroborate reliability.
“We knew from fact-finders that civilian witnesses do not necessarily know what metadata is or that they should include it with their information – even something as simple as panning the horizon for landmarks or turning on geolocation features. The Whistle prompts them for the information at the time of upload, so the fact-finders don’t have to piece it together later. It also provides individuals with information literacy – helps them understand what characteristics their information should ideally have in order to do things for them.”
Initially funded by Cambridge’s Economic and Social Research Council Impact Acceleration Account, the Whistle is now funded by the European Union as part of ‘ChainReact’, a multi-partner programme to support whistle-blowing in business. The team has grown to six members and plans to start using the demo of the Whistle to gain feedback from NGOs and civilian witnesses.
McPherson sees the Whistle as a tool for NGOs to use in the field, rather than as a global repository of information, since the latter would create security risks for the whistle-blowers: “Security challenges vary a lot according to context, and we don’t see ourselves as ever being able to anticipate all the security challenges of a local context – it depends on the threat model. So we always want to partner with local organisations.” Although civilians may never have heard of the Whistle, they are likely to be aware of the support of a local NGO, who would then direct them towards the tool as a means to submit information. “It would then be up to the NGO to decide what to do with the data,” she explains.
McPherson is reflective when she considers the implications of a digital world that requires tools such as the Whistle to verify trustworthiness. “Reporting violations and fact-finding are communicative acts of ‘bearing witness’ – inherently human activities that involve solidarity, support and rapport. Technological innovations mean that we may increasingly have to replace this with reporting to a machine – how do you balance that opportunity with safeguards around traumatisation? This is something we don’t yet have answers for.”
Nevertheless, she and her team are aware that an increase in digital information on human rights violations only translates into evidence once it is validated. “Tools like the Whistle are desperately needed by fact-finders to reduce the labour time in sifting the wheat from the chaff, and to make it easier for them to evaluate more digital information for evidence.
“We hope that our platform will increase the possibility that those who report violations receive attention, and particularly that those who most need access to human rights mechanisms are heard.”
The team behind the Whistle include Dr Ella McPherson, Rebekah Larsen, Giles Barton-Owen, Isabel Guenette Thornton, Matt Mahmoudi, Sarah Villeneuve, Dr Richard Mills and Scott Limbrick.
Smartphones and social media have made it easy for accidental witnesses “in the wrong place at the wrong time” to capture and share violations and crimes. But how can we tell what’s real and what’s fake?
Currently, methods to detect vCJD-infected human blood samples that involve experimental animals, such as mice, are time consuming and expensive. This new test could potentially be used on blood samples collected during pre-clinical disease and would be able to give a result in a matter of days or weeks rather than months or years.
In the late eighties, the UK saw an outbreak of bovine spongiform encephalopathy (BSE), a fatal brain condition in cattle, often referred to as ‘mad cow disease.’ BSE is a type of neurodegenerative brain condition known as a prion disease, caused by the build-up of a rogue form of a normal protein found in neurons. This aggregated form of the normal protein is referred to as a prion and is infectious. Following the BSE outbreak, a number of people were diagnosed with vCJD, a fatal human prion disease, believed to have occurred through the consumption of BSE-contaminated beef. vCJD causes changes in mood and behaviour, followed by difficulty in walking, and eventually leads to loss of movement and speech before death.
Other cases of vCJD have occurred in patients who received blood products prepared from donors who themselves later developed the disease; hence, blood-borne transmission of vCJD is a major concern for blood transfusion banks, manufacturers of blood plasma-derived products and public health authorities.
Although the number of people known to have died from vCJD is small – less than 180 cases in the UK – recent research has suggested that, within a certain age group of people in the UK, the number of individuals infected with vCJD, but who have not developed clinical signs of the condition, could be as high as one person in 2,000. Whether these individuals will go on to develop the clinical form of the disease during their natural life span remains uncertain.
At the moment, the only reliable way to detect infectious prions in blood is through a test known as a bioassay. This involves injecting suspected infected samples into experimental animals and waiting to see if these recipients develop prion disease. This is usually carried out by injecting potentially prion-infected samples into the brains of mice. These assays are slow and cumbersome, since the incubation time for prion disease may be over a year. This means that very few blood samples are routinely screened for prion infectivity.
Now, in a study published today in the Biochemical Journal, scientists at the University of Cambridge, UK, and the Ecole Nationale Veterinaire de Toulouse, France, report the development of a genetically-modified fruit fly (Drosophila melanogaster) into which a gene has been inserted to make the fly capable of producing the rogue protein that aggregates in the brain of sheep with the prion disease scrapie.
When the researchers fed these transgenic flies plasma from sheep known to have prions in their blood, they found that this caused prion disease in the flies. This response to prion-infected blood was evident within only a few weeks after exposure to the material.
Dr Raymond Bujdoso from the Department of Veterinary Medicine at the University of Cambridge, who led the research, says: “We have found the fruit flies respond so quickly to infected blood that it means we can develop a faster, more versatile and more sensitive test to detect infectious prions in blood than currently exists.
“At the moment, screening blood products for vCJD prion infectivity is just not practical – it is expensive and time consuming, and would require the use of a large number of animals, which is ethically unacceptable. The development of a vCJD blood test that could easily and reliably screen for prion-infectivity would represent an ideal solution for identifying donors and blood donations that might present a risk of causing the disease.”
Fruit flies are relatively easy and economical to work with, and widely accepted to be an ethical alternative to higher organisms such as mice. Dr Bujdoso and colleagues say that their fruit fly model will help contribute to the so-called 3Rs – the replacement, refinement and reduction of the use of animals in research.
Professor David Carling, Chair of the Biochemical Journal, adds: “The paper from Dr Bujdoso and colleagues provides a proof-of-principle study demonstrating that the fruit fly can be used to detect the infectious agent responsible for a type of neurodegenerative disease. Although the work is at a preliminary stage, it offers the exciting possibility of developing a quick and reliable screen for early diagnosis of a devastating disease.”
The research was supported by the Isaac Newton Trust and the National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs).
Thackray, AM, Andréoletti, O and Bujdoso, R. Bioassay of prion-infected blood plasma in PrP transgenic Drosophila. Biochem Journal; 13 Oct 2016; 10.1042/BCJ20160417
A new model of fatal brain diseases is being developed in the fruit fly by a team led by Dr Raymond Bujdoso at the University of Cambridge, and could lead to a low cost, fast and efficient blood test to diagnose – and prevent possible transmission of – variant Creutzfeldt-Jakob disease (vCJD).
Researchers have developed a new technique for making calculations in “high-dimensional space” – mathematical problems so wide-ranging in their scope, that they seem at first to be beyond the limits of human calculation.
In what sounds like the title of a rejected script for an Indiana Jones movie, the method improves on existing approaches to beat a well-known problem known as “The Curse Of Dimensionality”. It was devised by a team of researchers at the University of Cambridge.
In rough terms, the “Curse”, refers to the apparent impossibility of making calculations in situations where the number of variables, attributes, and possible outcomes is so large that it seems futile even to try to comprehend the problem in the first place.
A simple example is this: Imagine that you have a cup containing 100 grains of rice. You pick it up, shake it, and put it down again. The arrangement within the cup changes, but what are the chances of that arrangement occurring, relative to all other possibilities?
While most people would reasonably consider that problem not just impossible, but largely pointless, it illustrates the type of maths needed to make predictions about much bigger – and more meaningful – issues.
Those include, for example, trying to model the likely shape and impact of a decaying ecosystem, such as a developing area of deforestation, or the potential effect of different levels of demand on a power grid. More fundamentally, the same class of calculation would theoretically enable us to get to grips with the statistical probability of our own existence on Earth, or the chances that life might happen again, elsewhere in the Universe.
The new study was led by Stefano Martiniani, a Gates Scholar at St John’s College, Cambridge, who carried out the work with colleagues in the Department of Chemistry and at Microsoft Research in Cambridge.
“There is a very large class of problems that can be solved through the sort of approach that we have devised,” Martiniani said. “It opens up a whole world of possibilities in the study of things like dynamical systems, chemical structure prediction, or artificial neural networks.”
Most people understand “dimensions” to mean height, width, depth and time, but in Mathematics the term is also used flexibly to describe the number of parameters needed to specify a “state” for any given problem. The more complicated the problem in question, the greater the space you need to express the parameters. They therefore become “high-dimensional spaces”.
Similarly, working out the likelihood of a particular outcome in a situation where all sorts of different variables apply – such as the grains of rice in a cup arranging themselves in a particular way – is a high-dimensional problem. Expressing and plotting the combined impact of the many parameters that might affect the outcome involves imagining a graph with multiple axes, as if working in numerous dimensions at once.
The method devised by Martiniani and colleagues, like other approaches, begins by characterising such challenges as an “energy landscape”. The range of possible states in which a system such as the cup of rice may exist is envisaged as a landscape of mountains and valleys, in which the base of each valley is a stable state.
The set of initial conditions leading to this stable state is called a “basin of attraction”. The fundamental theory is that, if the volume of each basin of attraction can be calculated, then this begins to provide some sort of indication of the probability of a given state’s occurrence.
To do that, researchers build computer software which models high dimensional systems, using the landscape analogy, and makes calculations within it.
The simplest model is a brute force approach, which essentially takes a reading, shakes the system up, takes another reading, and repeats the process – many millions of times – in an attempt to establish the probability of certain outcomes. A more sophisticated strategy recurrently starts in the same place and measures the average distance within the energy landscape in which the system finds the same basin of attraction, through which the user gradually develops an appreciation of its volume.
“In most cases you are like a blindfolded person, walking around drunk in the energy landscape,” Martiniani said. “At any given moment, you only really know where you are and where you have just come from.”
In the new study, however, the team applied a different approach to the same kind of problem. Borrowing a technique widely used in biomolecular simulations, called the Multistate Bennett Acceptance Ratio, they developed a method which systematically tests the limits of one particular basin of attraction. Rather than gauging its volume by just taking an average from random samples, it looks for the furthest and least likely limits.
The net result is a much more efficient sampling technique, which enables a much broader range of calculations in high-dimensional space.
To test this, the team modelled an imaginary 93-dimensional “system” made up of 32 soft spheres that could be packed together in multiple ways. They found that they were able to sample and quantify outcomes within that system that would only be found randomly one in every 10100 times. In other words, the chances of stumbling across those outcomes by chance would be one in ten duotrigintillion.
“In basic terms it goes where brute force sampling never will, because if you started to try, you would never finish,” Martiniani added. “Technically, the limits of the problems we can solve are now not those of the approach, but the computing power we need to simulate the underlying energy landscape. When addressing these kinds of problems in high-dimensional space, this should now be the technique of choice.”
The study, Structural analysis of high-dimensional basins of attraction, is published in the journal Physical Review E.
Researchers have developed a new method for making effective calculations in “high-dimensional space” – and proved its worth by using it to solve a 93-dimensional problem.
On a dark night late in 1592, a group of Englishmen was massacred on the island of São Sebastião, off the southeast coast of Brazil. Most had deserted the infamous English privateer Thomas Cavendish less than two weeks before in the hope they could find a living in Brazil. But this was not to be. A band of Portuguese and their allied Indians from Rio de Janeiro set upon them in the early hours: they were dragged to the shore, where their skulls were smashed with “fire brands”.
At the time, English subjects were considered enemies of Spain and Portugal, “heretic Lutherans” who were officially forbidden to set foot on the Iberian colonies in the New World. But Cavendish’s men were not innocent: only a couple of months earlier they had besieged towns, burned down mills and plundered villages along the Brazilian coast.
The massacre in São Sebastião would have remained unknown, had it not been for one who managed to survive and later write what would become the earliest extensive account of Brazil written by an Englishman. This man was Anthony Knivet, a young soldier from Norfolk with few scruples and a great desire for fortune.
Knivet would spend the next nine years living in Brazil – mostly in or around the incipient village of Rio de Janeiro– working as a drudge for the ruling Portuguese. After all, the only reason he escaped being killed in São Sebastião was his swift offer to trade information on the English in exchange for his life. This would be the first of many brushes with death that Knivet would experience in Brazil. He would also, while serving the Portuguese as a slaver, travel vast portions of a territory then virtually unknown by Europeans, encountering a myriad of native tribes, many of which would have been destroyed by the following century.
From the vantage point of an outsider, Knivet witnessed first-hand several aspects that characterised Brazilian colonial society in its very beginnings: the harsh life at the early sugar-mills – the “engenhos” – the multiracial settlements, the political disputes, the exploitation of labour and the violent expansion towards the unknown “interior”. Though we do not know exactly how he managed to finally extricate himself from the hands of the Portuguese, we know that he arrived back in England in 1601, and in 1625 the remarkable story of his adventures came out in print as The Admirable Adventures and Strange Fortunes of Master Antonie Knivet, who went with Master Thomas Cavendish to the South Sea, 1591.
Published in a compendium of travel accounts, the Admirable Adventures had not attracted much sympathy or credence until recently, and remained mostly unknown to the broader public. It received its first single annotated edition in English only last year.
One reason for this lasting disregard may have been Knivet’s obscure background, his poor writing skills, together with allusions to mermaids and “glistening mountains”. Even his original editor, Samuel Purchas, was reticent about endorsing some of his descriptions. However, on close inspection and when verified against Portuguese documents, several events, names and descriptions in the narrative turn out to be surprisingly accurate.
Portrait of a survivor
Perhaps there is another aspect that has kept Knivet’s story obscure: in a seeming endless string of narrow escapes from death, Knivet emerges as someone whose only loyalty is to saving his own skin at any cost, even if it meant betraying the English, the Portuguese or the Indians. In the ruthless world of colonial disputes and bloody encounters, Knivet became a master of survival, a skillful improviser who aptly manipulated cultural tensions to his own advantage.
Knivet tells us how, after breaking off from an expedition along with 12 young Portuguese, he encounters a tribe of Tamoio living deep in the hinterland. Knowing of the enmity between Tamoio and Portuguese, Knivet aptly declares himself French before all his Portuguese companions are executed and ritually devoured. The ensuing year is spent living with the tribe until he convinces his hosts to engage in a mass migration to the coast in search of fisheries and French trading ships.
What Knivet tells his readers (but did not tell his hosts) is that he in fact longed to find a safe passage back to England. In truth, Knivet led the tribe straight to a notorious slave-trading post kept by the Portuguese on the coast. As a result, the last known tribe of Tamoio to have escaped Portuguese conquest in the 1550s was then either massacred or enslaved.
The Admirable Adventures renders the interplay between fact and fiction even more problematic as we deal with a narrator who can be disconcertingly frank while remaining unnervingly opaque. Apart from its fascinating glimpse into an under-documented time in colonial Brazil, Knivet’s account tells us a lot about the interplay of truth and fiction in early modern travel writing.
The author will be giving a talk on Anthony Knivet as part of the Cambridge Festival of Ideas from October 17 to 30.
Vivien Kogut Lessa de Sá (Department of Spanish & Portuguese) discusses the life and times of Anthony Knivet, a young soldier from Norfolk who spent nine years living in Brazil in the 16th century. She will be discussing Knivet's life on 22 October as part of the Cambridge Festival of Ideas.
For all the controversy it caused, Fitna is not a great film. The 17-minute short, by the Dutch far-right politician Geert Wilders, was a way for him to express his opinion that Islam is an inherently violent religion. Understandably, the rest of the world did not see things the same way. In advance of its release in 2008, the film received widespread condemnation, especially within the Muslim community.
When a trailer for Fitna was released on YouTube, authorities in Pakistan demanded that it be removed from the site. YouTube offered to block the video in Pakistan, but would not agree to remove it entirely. When YouTube relayed this decision back to the Pakistan Telecommunications Authority (PTA), the decision was made to block YouTube.
Although Pakistan has been intermittently blocking content since 2006, a more persistent blocking policy was implemented in 2011, when porn content was censored in response to a media report that highlighted Pakistan as the top country in terms of searches for porn. Then, in 2012, YouTube was blocked for three years when a video, deemed blasphemous, appeared on the website. Only in January this year was the ban lifted, when Google, which owns YouTube, launched a Pakistan-specific version, and introduced a process by which governments can request the blocking of access to offending material.
All of this raises the thorny issue of censorship. Those censoring might raise objections to material on the basis of offensiveness or incitement to violence (more than a dozen people died in Pakistan following widespread protests over the video uploaded to YouTube in 2012). But when users aren’t able to access a particular site, they often don’t know whether it’s because the site is down, or if some force is preventing them from accessing it. How can users know what is being censored and why?
“The goal of a censor is to disrupt the flow of information,” says Sheharbano Khattak, a PhD student in Cambridge’s Computer Laboratory, who studies internet censorship and its effects. “internet censorship threatens free and open access to information. There’s no code of conduct when it comes to censorship: those doing the censoring – usually governments – aren’t in the habit of revealing what they’re blocking access to.” The goal of her research is to make the hidden visible.
She explains that we haven’t got a clear understanding of the consequences of censorship: how it affects different stakeholders, the steps those stakeholders take in response to censorship, how effective an act of censorship is, and what kind of collateral damage it causes.
Because censorship operates in an inherently adversarial environment, gathering relevant datasets is difficult. Much of the key information, such as what was censored and how, is missing. In her research, Khattak has developed methodologies that enable her to monitor censorship by characterising what normal data looks like and flagging anomalies within the data that are indicative of censorship.
She designs experiments to measure various aspects of censorship, to detect censorship in actively and passively collected data, and to measure how censorship affects various players.
The primary reasons for government-mandated censorship are political, religious or cultural. A censor might take a range of steps to stop the publication of information, to prevent access to that information by disrupting the link between the user and the publisher, or to directly prevent users from accessing that information. But the key point is to stop that information from being disseminated.
Internet censorship takes two main forms: user-side and publisher-side. In user-side censorship, the censor disrupts the link between the user and the publisher. The interruption can be made at various points in the process between a user typing an address into their browser and being served a site on their screen. Users may see a variety of different error messages, depending on what the censor wants them to know.
“The thing is, even in countries like Saudi Arabia, where the government tells people that certain content is censored, how can we be sure of everything they’re stopping their citizens from being able to access?” asks Khattak. “When a government has the power to block access to large parts of the internet, how can we be sure that they’re not blocking more than they’re letting on?”
What Khattak does is characterise the demand for blocked content and try to work out where it goes. In the case of the blocking of YouTube in 2012 in Pakistan, a lot of the demand went to rival video sites like Daily Motion. But in the case of pornographic material, which is also heavily censored in Pakistan, the government censors didn’t have a comprehensive list of sites that were blacklisted, so plenty of pornographic content slipped through the censors’ nets.
Despite any government’s best efforts, there will always be individuals and publishers who can get around censors, and access or publish blocked content through the use of censorship resistance systems. A desirable property, of any censorship resistance system is to ensure that users are not traceable, but usually users have to combine them with anonymity services such as Tor.
“It’s like an arms race, because the technology which is used to retrieve and disseminate information is constantly evolving,” says Khattak. “We now have social media sites which have loads of user-generated content, so it’s very difficult for a censor to retain control of this information because there’s so much of it. And because this content is hosted by sites like Google or Twitter that integrate a plethora of services, wholesale blocking of these websites is not an option most censors might be willing to consider.”
In addition to traditional censorship, Khattak also highlights a new kind of censorship – publisher-side censorship – where websites refuse to offer services to a certain class of users. Specifically, she looks at the differential treatments of Tor users by some parts of the web. The issue with services like Tor is that visitors to a website are anonymised, so the owner of the website doesn’t know where their visitors are coming from. There is increasing use of publisher-side censorship from site owners who want to block users of Tor or other anonymising systems.
“Censorship is not a new thing,” says Khattak. “Those in power have used censorship to suppress speech or writings deemed objectionable for as long as human discourse has existed. However, censorship over the internet can potentially achieve unprecedented scale, while possibly remaining discrete so that users are not even aware that they are being subjected to censored information.”
Professor Jon Crowcroft, who Khattak works with, agrees: “It’s often said that, online, we live in an echo chamber, where we hear only things we agree with. This is a side of the filter bubble that has its flaws, but is our own choosing. The darker side is when someone else gets to determine what we see, despite our interests. This is why internet censorship is so concerning.”
“While the cat and mouse game between the censors and their opponents will probably always exist,” says Khattak. “I hope that studies such as mine will illuminate and bring more transparency to this opaque and complex subject, and inform policy around the legality and ethics of such practices.”
Despite being founded on ideals of freedom and openness, censorship on the internet is rampant, with more than 60 countries engaging in some form of state-sponsored censorship. A research project at the University of Cambridge is aiming to uncover the scale of this censorship, and to understand how it affects users and publishers of information
Is digital media making us stupid? What is the future of our libraries? Is smartphone fiction the future of reading?
Questions about how technology is shaping our culture and identity are at the forefront of this year’s Cambridge Festival of Ideas, which starts today.
The Festival covers a huge range of some of the biggest social, political and cultural issues of our time, from our digital future to human trafficking, Europe, religion and nationalism and academic freedom. Now in its ninth year, the two-week long Festival is teeming with over 200 events, from films and plays to exhibitions to talks, most of them free.
It features a number of leading thinkers and innovators, including Fiona Hill, Joint Downing Street Chief of Staff, lead author of the Modern Slavery Act 2015 and author of A Modern Response to Modern Slavery Report; Professor of International History David Reynolds; Developer and Founder of Skype, and co-founder of The Future of Life Institute and the Centre for the Study of Existential Risk, Jaan Tallin; Europol Director Rob Wainwright; Director of the Global Initiative against Transnational Organized Crime Tuesday Reitano; Director of the UK Intersex Association Dr Jay Hayes-Light; and award-winning Guardian correspondent Luke Harding.
The Festival sponsors and partners are Cambridge University Press, St John’s College, Anglia Ruskin University, RAND Europe, Microsoft Research, Cambridge Assessment, University of Cambridge Language Centre, Arts Council England, University of Cambridge Museums and Botanic Garden, Cambridge Junction, Arts and Humanities Research Council, and the Festival media partner is BBC Radio Cambridgeshire.
The Cambridge Festival of Ideas runs from 17th to 30th October.
Tuesday 18 October, 12-1pm, Faculty of Law
Wednesday 19 October, 12-1pm, Faculty of Law
Thursday 20 October, 12-1pm, Faculty of Law
Thursday 20 October, 5-6.30pm, Fitzpatrick Hall, Queen's College
The Rt. Hon. Greg Hands MP, Minister of State in the Department for International Trade will give this year’s Alcuin Lecture at the Department of Politics and International Studies (POLIS).
Thursday 20 October, 7-8.30pm, Fisher Building, St John's College
Friday 21 October, 5-7pm, Cavonius Centre, Gonville & Caius College, West Road, Cambridge
Saturday 22 October, 10-11.30am, Battle of ideas, The Barbican, London
For more details and booking see the Battle of ideas site.
This week, in conjunction with UK in a Changing Europe, the University is holding a number of interdisciplinary discussion events to engage students and the local community in key current debates about Brexit and the UK’s future relationship with the EU.
‘Cryptocurrency’ is a form of finance that exists only online. Unlike national currencies like the British pound, it isn’t forged as coins or printed as notes and no central authority governs it.
Most often it’s associated with an eclectic mix of individuals: gamers, hackers and the tech-savvy; anti-authority libertarians who believe in a global currency; gamblers happy to speculate on ‘digital gold’; shady dealers, money launderers, users of adult content services and the dark web; forward-thinking members of the financial sector.
But it has also been looked at as one possible solution to help a very different demographic – the world’s poorest poor, the so-called bottom billion. Many in this demographic lack bank accounts, have difficulty in proving they own their own land or business, and frequently depend on sending or receiving money across borders to poorer relatives.
In fact only one in five adults living on less than $2 per day has a bank account, and nearly 80% of poor adults, or two billion people, are excluded from the formal financial system. Meanwhile, the World Bank estimates that 75% of the $581.6 billion global remittances in 2015 were sent to developing countries.
But how can cryptocurrencies help? Since its launch in 2009, bitcoin, the most well known of digital currencies, has had a chequered history. Issues with market volatility, security and regulation, together with its association with online black markets like the now defunct Silk Road, have created suspicion among citizens and policymakers alike.
And yet, a recent headline in Wired stated: “Thought bitcoin was dead? 2016 is the year it goes big”; the reason, they explained, is it can “provide a much cheaper and simpler way of moving money from place to place, particularly when you’re a consumer or business moving it across international borders or a retailer accepting payments from online buyers.”
Dr Garrick Hileman, who researches the impact of cryptocurrency on world finance at the Cambridge Centre for Alternative Finance, adds: “And it’s not just transfer fees. Conventional financial systems can suffer from slow transfer times, inconvenient hours for completion of transfers, limited access to transfers, and the failure of approximately 2% of all international transfers to be successfully completed. These all negatively impact remittances.”
He and colleagues have been looking at which markets and countries are the most likely to adopt cryptocurrencies based on 40 different factors, ranging from degree of technology penetration to cross-border transactions fees to history of financial crises and inflation. The results indicate that Sub-Saharan Africa, Latin America and former-Soviet Union countries have the greatest potential for adopting cryptocurrency.
“Cryptocurrency is an immature technology and is not without flaws. However, as with any new technology, it’s the applications that have ignited interest – it’s raised important questions about how cross-border payments can be improved and, wider still, whether the very special type of ledger system that underpins cryptocurrency can be used for any number of other areas.”
At the heart of bitcoin is the ‘blockchain’, a database that records all transactions chronologically through a unique series of numbers arranged in ‘blocks’, which are then ‘chained’ to the next block cryptographically, so as to be both secure and accurate. This linking of information makes them like a financial ledger, but unlike centralised banking systems, the blockchain is a database that can be stored and shared worldwide by anyone with a computing device and internet connection – hence its description as a distributed ledger technology (DLT).
Part of the promise of cryptocurrency lies in the absence of a gatekeeper in its set-up, as Hileman explains: “Transactions occur person to person, or machine to machine, without the need for third party institutions – and that means lower or no transaction fees.”
“For the seven years bitcoin has been operating, there hasn’t been a single minute of downtime, unlike traditional IT networks employed by banks and other institutions. This resiliency has people’s attention,” says Hileman. “And currency is not the only thing that DLT can be used for. It can be used to exchange anything that has value – stocks, houses, airline miles, notarisations, votes.”
This year, the Government Office of Science published a report in which Chief Scientific Advisor Professor Sir Mark Walport described distributed ledgers as “powerful, disruptive innovations that could transform the delivery of public and private services” and “provide new ways of assuring ownership and provenance for goods and intellectual property.”
One of the recommendations was for the UK research community to ensure that distributed ledgers are scalable and secure. The report added that the Alan Turing Institute – a joint venture by the universities of Cambridge, Edinburgh, Oxford, University College London, Warwick and the Engineering and Physical Sciences Research Council – would help to support these endeavours.
“We probably have yet to see the full extent of future uses of distributed ledgers,” adds Hileman. “However, our research has shown that cross-border transactions are viewed as one of the most promising applications of distributed ledger tech, due to the high transaction fees, technical interoperability issues, complex and conflicting regulatory frameworks, and legacy equipment and processes associated with existing systems.”
To realise this potential, he says, there are problems that need to be solved for customers in developing countries: “people know they are being stung by transaction fees but are still reluctant to switch for a wide range of reasons.”
“It could even be that banks themselves adopt the technology, and yet still enable its distributed peer-to-peer set-up, offering it as a separate service to their traditional monetary services. In other words, customers may never know their transactions are happening on a blockchain,” he adds.
Bitcoin has had a volatile exchange rate and Hileman concedes that it’s too early to know whether regulatory measures will help shield customers from this and other risks, or reduce money laundering and financial crimes committed with bitcoin. In the meantime, the Centre’s work on benchmarking cryptocurrency and blockchain activity will provide useful data for policymakers and other stakeholders keeping an eye on the technology.
“More than $430 billion was sent in remittances to developing countries in 2015, mostly to India, but also China, Mexico and Nigeria,” says Hileman. “The costs of these transactions – which can average as high as 12% in Sub-Saharan Africa – hit the poor the hardest. Technological advances like cryptocurrency and distributed ledgers may offer a solution.
“It would be surprising to me if in 30 years from now we aren’t looking back and saying yes this was a watershed moment for financial inclusion, and that cryptocurrency and distributed ledgers played a significant role in opening up access to the financial system in developing economies.”
Many of the world’s poorest poor don’t have access to a bank account and yet depend on being able to transfer money across borders. Could digital currency help, ask researchers at the Cambridge Centre for Alternative Finance.
Physicists have successfully employed a powerful technique for studying electrons generated through singlet fission, a process which it is believed will be key to more efficient solar energy production in years to come.
Their approach, reported in the journal Nature Physics, employed lasers, microwave radiation and magnetic fields to analyse the spin of excitons, which are energetically excited particles formed in molecular systems.
These are generated as a result of singlet fission, a process that researchers around the world are trying to understand fully in order to use it to better harness energy from the sun. Using materials exhibiting singlet fission in solar cells could make energy production much more efficient in the future, but the process needs to be fully understood in order to optimize the relevant materials and design appropriate technologies to exploit it.
In most existing solar cells, light particles (or photons) are absorbed by a semiconducting material, such as silicon. Each photon stimulates an electron in the material's atomic structure, giving a single electron enough energy to move. This can then potentially be extracted as electrical current.
In some materials, however, the absorption of a single photon initially creates one higher-energy, excited particle, called a spin singlet exciton. This singlet can also share its energy with another molecule, forming two lower-energy excitons, rather than just one. These lower-energy particles are called spin "triplet" excitons. Each triplet can move through the molecular structure of the material and be used to produce charge.
The splitting process - from one absorbed photon to two energetic triplet excitons - is singlet fission. For scientists studying how to generate more solar power, it represents a potential bargain - a two-for-one offer on the amount of electrical current generated, relative to the amount of light put in. If materials capable of singlet fission can be integrated into solar cells, it will become possible to generate energy more efficiently from sunlight.
But achieving this is far from straightforward. One challenge is that the pairs of triplet excitons only last for a tiny fraction of a second, and must be separated and used before they decay. Their lifespan is connected to their relative "spin", which is a unique property of elementary particles and is an intrinsic angular momentum. Studying and measuring spin through time, from the initial formation of the pairs to their decay, is essential if they are to be harnessed.
In the new study, researchers from the University of Cambridge and the Freie Universität Berlin (FUB) utilised a method that allows the spin properties of materials to be measured through time. The approach, called electron spin resonance (ESR) spectroscopy, has been used and improved since its discovery over 50 years ago to better understand how spin impacts on many different natural phenomena.
It involves placing the material being studied within a large electromagnet, and then using laser light to excite molecules within the sample, and microwave radiation to measure how the spin changes over time. This is especially useful when studying triplet states formed by singlet fission as these are difficult to study using most other techniques.
Because the excitons' spin interacts with microwave radiation and magnetic fields, these interactions can be used as an additional way to understand what happens to the triplet pairs after they are formed. In short, the approach allowed the researchers to effectively watch and manipulate the spin state of triplet pairs through time, following formation by singlet fission.
The study was led by Professor Jan Behrends at the Freie Universität Berlin (FUB), Dr Akshay Rao, a College Research Associate at St John's College, University of Cambridge, and Professor Neil Greenham in the Department of Physics, University of Cambridge.
Leah Weiss, a Gates-Cambridge Scholar and PhD student in Physics based at Trinity College, Cambridge, was the paper's first author. "This research has opened up many new questions," she said. "What makes these excited states either separate and become independent, or stay together as a pair, are questions that we need to answer before we can make use of them."
The researchers were able to look at the spin states of the triplet excitons in considerable detail. They observed pairs had formed which variously had both weakly and strongly-linked spin states, reflecting the co-existence of pairs that were spatially close and further apart. Intriguingly, the group found that some pairs which they would have expected to decay very quickly, due to their close proximity, actually survived for several microseconds.
"Finding those pairs in particular was completely unexpected," Weiss added. We think that they could be protected by their overall spin state, making it harder for them to decay. Continued research will focus on making devices and examining how these states can be harnessed for use in solar cells."
Professor Behrends added: "This interdisciplinary collaboration nicely demonstrates that bringing together expertise from different fields can provide novel and striking insights. Future studies will need to address how to efficiently split the strongly-coupled states that we observed here, to improve the yield from singlet fission cells."
Beyond trying to improve photovoltaic technologies, the research also has implications for wider efforts to create fast and efficient electronics using spin, so-called "spintronic" devices, which similarly rely on being able to measure and control the spin properties of electrons.
The research was made possible with support from the UK Engineering and Physical Sciences Research Council (EPSRC) and from the Freie Universität Berlin (FUB). Weiss and colleague Sam Bayliss carried out the spectroscopy experiments within the laboratories of Professor Jan Behrends and Professor Robert Bittl at FUB. The work is also part of the Cambridge initiative to connect fundamental physics research with global energy and environmental challenges, backed by the Winton Programme for the Physics of Sustainability.
The study, Strongly exchange-coupled triplet pairs in an organic semiconductor, is published in Nature Physics. DOI: 10.1038/nphys3908.
In a new study, researchers measure the spin properties of electronic states produced in singlet fission – a process which could have a central role in the future development of solar cells.
Researchers from the Department of Psychiatry at Cambridge led a team that analysed data from 20 clinical trials involving the use of anti-cytokine drugs to treat a range of autoimmune inflammatory diseases. By looking at additional beneficial side-effects of the treatments, the researchers were able to show that there was a significant antidepressant effect from the drugs compared to a placebo based on a meta-analysis of seven randomised controlled trials. Meta-analyses of the other types of clinical trials showed similar results.
When we are exposed to an infection, for example influenza or a stomach bug, our immune system fights back to control and remove the infection. During this process, immune cells flood the blood stream with proteins known as cytokines. This process is known as systemic inflammation.
Even when we are healthy, our bodies carry trace levels of these proteins – known as ‘inflammatory markers’ – which rise exponentially in response to infection. Previous work from the team found that children with high everyday levels of one of these markers are at greater risk of developing depression and psychosis in adulthood, suggesting a role for the immune system, particularly chronic low-grade systemic inflammation, in mental illness.
Inflammation can also occur as a result of the immune system mistaking healthy cells for infected cells and attacking the body, leading to autoimmune inflammatory diseases such as rheumatoid arthritis, psoriasis and Crohn’s disease. New types of anti-inflammatory drugs called anti-cytokine monoclonal antibodies and cytokine inhibitors have been developed recently, some of which are now routinely used for patients who respond poorly to conventional treatments. Many more are currently undergoing clinical trials to test their efficacy and safety.
The team of researchers carried out a meta-analysis of these clinical trials and found that the drugs led to an improvement in the severity of depressive symptoms independently of improvements in physical illness. In other words, regardless of whether a drug successfully treated rheumatoid arthritis, for example, it would still help improve a patient’s depressive symptoms. Their results are published today in the journal Molecular Psychiatry.
Dr Golam Khandaker, who led the study, says: “It’s becoming increasingly clear to us that inflammation plays a role in depression, at least for some individuals, and now our review suggests that it may be possible to treat these individuals using some anti-inflammatory drugs. These are not your everyday anti-inflammatory drugs such as ibuprofen, however, but a particular new class of drugs.”
“It’s too early to say whether these anti-cytokine drugs can be used in clinical practice for depression, however,” adds Professor Peter Jones, co-author of the study. “We will need clinical trials to test how effective they are in patients who do not have the chronic conditions for which the drugs have been developed, such as rheumatoid arthritis or Crohn’s disease. On top of this, some existing drugs can have potentially serious side effects, which would need to be addressed.”
Dr Khandaker and colleagues believe that anti-inflammatory drugs may offer hope for patients for whom current antidepressants are ineffective. Although the trials reviewed by the team involve physical illnesses that trigger inflammation – and hence potentially contribute to depression – their previous work found a connection between depression and baseline levels of inflammation in healthy people (when someone does not have an acute infection), which can be caused by a number of factors such as genes and psychological stress.
“About a third of patients who are resistant to antidepressants show evidence of inflammation,” adds Dr Khandaker. “So, anti-inflammatory treatments could be relevant for a large number of people who suffer from depression.
“The current approach of a ‘one-size-fits-all’ medicine to treat depression is problematic. All currently available antidepressants target a particular type of neurotransmitter, but a third of patients do not respond to these drugs. We are now entering the era of ‘personalised medicine’ where we can tailor treatments to individual patients. This approach is starting to show success in treating cancers, and it’s possible that in future we would use anti-inflammatory drugs in psychiatry for certain patients with depression.”
The research was mainly funded by the Wellcome Trust, with further support from the National Institute for Health Research (NIHR) Cambridge Biomedical Research Centre.
Kappelmann, N et al. Antidepressant activity of anti-cytokine treatment: a systematic review and meta-analysis of clinical trials of chronic inflammatory conditions. Molecular Psychiatry; 18 Oct 2016; DOI: 10.1038/mp.2016.167
Anti-inflammatory drugs similar to those used to treat conditions such as rheumatoid arthritis and psoriasis could in future be used to treat some cases of depression, concludes a review led by the University of Cambridge, which further implicates our immune system in mental health disorders.
In the fourth of a new series of comment pieces written by linguists at Cambridge, Wendy Ayres-Bennett, Professor of French Philology and Linguistics, argues that the UK Government needs a coherent policy on languages as the country prepares to leave the EU.
Cambridge University Association Football Club (CUAFC) will take its place in the National Football Museum Hall of Fame tonight (October 19) alongside England greats like defenders Rio Ferdinand and Rachel Unitt, and goalkeepers David Seaman and Rachel Brown-Finnis.
They will be immortalised next to legends such as Sir Tom Finney, Gordon Banks, Alan Shearer and last year’s inductees Gary Neville and Norman Hunter.
Nick Brooking, Director of Sport at the University said: “Sport plays a major part in the amazing student experience at Cambridge and this award shows how far back our involvement and passion for football goes.
“This is a great honour and it is right that the University football club’s pivotal role in the history of the beautiful game should be recognised in this way.”
The University’s links with the rules of football are said to go all the way back to 1846 when Henry De Winton and John Charles Thring formed a club. In 1848 it’s said they held a meeting in Cambridge, aimed at creating a definitive set of rules for the game of football.
Up until that point, in many parts of the country, football was fairly unrecognisable as a sport, it had no structure and games were unruly, often ending in violence and brawling.
De Winton and Thring eventually established a code and ten simple rules known as the ‘Cambridge rules’ were pinned up on trees along the city’s large public playing fields, Parker’s Piece, where football is still played today.
This code, which included the first articulation of an off-side rule, went on to form the basis for the Football Association rules which established the modern game.
Dr John Little, President of CUAFC, said: “Before the code was produced things were quite chaotic. Players would have to read whatever set of rules had been posted on a tree near to where the game was to be played and decide if they were rules they familiar with before they played. In Cambridge it was decided it would be better if one set of rules was agreed on so that everyone could play against each other.”
With its links said to go back to 1846, the oldest existing document which names the club and the rules, dates back to 1856. So CUAFC can claim to be, unofficially at least, the oldest club in the world which is still playing. Though Sheffield FC (founded 1857), is recognised as the oldest club by the Football Association, CUAFC was awarded an illuminated plaque in 2006 by the FA in honour of its 150th anniversary, giving its foundation date official recognition.
There is no known written record of the original Cambridge Rules but Cambridge holds a collection of some early football memorabilia in its University Library. Perhaps the most significant item held by the library is the revised 1863 edition of The Winter Game by Thring.
This small volume includes Thring's own rules and the very recently published FA and Cambridge Rules of 1863.
Women’s Captain Gerda Bachrati, a veterinary medicine student at Gonville & Caius College, said: “Football has always been a family affair. I started playing when I was seven. When my sister started playing my father began coaching. I have a whole social network built out of it. When I came to Cambridge I wanted to keep that going - it can be quite lonely studying. I think to thrive at Cambridge you need a demanding activity to balance out the demanding academic life. It has made me more organised with my time and given me the chance to be a team leader long before I am expected to do it in my career. The award and recognition - for the Club and University - is amazing, adding to an exciting time for women’s sport at Cambridge"
Men’s captain Henry Warne, a politics student at Fitzwilliam College, said: "Football has been in my family my whole life. It is the main reason I came here - I went to a comprehensive so coming to Cambridge wasn’t something expected. But my uncle always said how getting a rugby blue when he was here and that it had been a great thing in his life. Since I was 15 I have wanted to get a football blue. I have loved Cambridge as a sporting and an academic opportunity."
He added: "To be captain when this is happening is special. I feel very lucky to be part of a club which such a long history and pivotal role and it is wonderful to have the external recognition of this great club.”
Both Bachrati and Warne agree that playing sports as a student has enriched their lives at Cambridge. "The sacrifice for football is great but sport in study helps not hinders. It motivates me to work hard.” said Warne, adding that around half of the squad last year got firsts in their studies.
The Varsity football match between the association football clubs of Cambridge University and Oxford University is one of the oldest regular fixtures in world football, having been played every year since 1873 (with breaks for the two World Wars).
The first Varsity match ended in a 1-0 victory for Oxford, with England international Robert Vidal scoring the only goal. The match is traditionally played at a neutral venue and was first played at Wembley in 1953.
Cambridge University’s 160 year old Football club has been honoured with a special award for its contribution to the history of the beautiful game and its place as “the oldest club in the world”
Sport at the University of Cambridge:
Cambridge University is recognised as much for its illustrious sporting tradition as it is for its excellence in education and research.
The Sports Service is the hub for all sport at the University, working with the clubs, maintaining an array of facilities across the city and offering everyone the chance to enjoy sport during their time in Cambridge. In addition to this, we work closely with the sporting community of the city at large, and anyone can be a member of our world-class Sports Centre. For more information go to: http://www.sport.cam.ac.uk/
For more on the CUAFC go to: www.facebook.com/CambridgeUniversityAFC/.
National Football Museum
The National Football Museum was established and its collection acquired thanks to £9.3m investment by the Heritage Lottery Fund.
The National Football Museum is a registered charity overseen by a board of trustees, and also counts notable names amongst its honorary positions, including Museum President Sir Bobby Charlton, Museum Vice Presidents Sir Alex Ferguson, Sir Trevor Brooking and Sir Geoff Hurst, plus Museum Special Ambassador Mark Lawrenson.
The museum also provides a permanent home for its nationally-recognised Hall of Fame, with new legends being inducted in a prestigious awards ceremony every year.
Entrance is free. To enhance the Museum experience, there are some additional exclusive paid-for interactive exhibits ‘Football Plus+’ to help ensure that visitors enjoy one of the best days out in the city.
Opening Times: Monday-Saturday 10am – 5pm
For more on the National Museum Hall of Fame:
About one in 14 people around the world are affected by anxiety disorders at any given time. Those who suffer from these conditions experience impairment, disability, and are at a high risk for substance abuse and suicide. In spite of these considerable risks, research on anxiety is lagging far behind that of other common mental health problems – and many people affected don’t even know they have this condition.
In many cases, a decade or more can elapse before someone who develops anxiety goes to the doctor for treatment. However, waiting this long can have potentially serious consequences. New research suggests that generalised anxiety disorder is associated with a two times higher risk for cancer deaths – but only in men.
How can this be?
Before we talk about the health effects of anxiety, a distinction needs to be made between normal anxiety and pathological anxiety – the kind of anxiety that we looked at in our study. Normal anxiety is something that all of us experience when we’re in threatening situations or when we’re preparing to deal with challenges, such as a stressful job interview.
When the anxiety becomes excessive, impairing and debilitating, however, that’s when an anxiety disorder can develop. For example, people with generalised anxiety disorder worry excessively and uncontrollably about a number of areas of life, they can’t control their worries and have trouble shifting their focus from one topic to another. They also experience symptoms such as irritability, restlessness, and muscle tension.
People with generalised anxiety disorder have difficulty focusing, and often experience insomnia and feel very tired as a result of this. This disorder can interfere with the formation and maintenance of social relationships, productivity at work and educational achievement. Those affected are more likely to be single or get divorced and are at a higher risk for depression compared to people who don’t suffer from this condition.
But many who have an anxiety disorder don’t suspect that they do. One of the reasons for this is that people often think that “anxiousness” is just part of their personality – in effect, that it is an intractable personality trait. This is also why people tend to wait a long time between symptom development and contact with the medical establishment. When help is finally sought, the anxiety has already progressed to an advanced stage, which then becomes more difficult to treat.
Another reason why waiting a long time to seek help for anxiety could be detrimental is that this mental health problem has been associated with increased risk for early death from cancer. But why? Previous studies have linked anxiety to inflammatory processes in the body and suppression of the immune system, which can increase the risk for diseases such as cancer.
Anxiety, therefore, could mask underlying health conditions or could represent an early warning signal for poor health that might occur down the road. Previous studies have shown that anxiety can increase the risk for a host of other negative outcomes, such as heart disease, diabetes, and thyroid conditions; importantly, symptoms of anxiety have also been shown to precede poor health. We have also found, for the first time, that anxiety is associated with an increased risk for early death from cancer in men.
Why are men more susceptible?
One reason may be that men tend to wait a long time before making a visit to the clinic when they feel unwell compared to women. Delay in seeking help can lead to underlying health conditions being detected at a later, more advanced stage, making them more difficult to treat successfully. Women, on the other hand, tend to see the doctor much sooner after experiencing symptoms compared to men, which leads to earlier detection and treatment of health problems.
We analysed data from a large study of more than 20,000 people. The rich data allowed us to look at the link between generalised anxiety disorder, measured in 1996-2000, and deaths from all cancers until 2015. We found that 126 out of 7,139 men and 215 out of 8,799 women had anxiety, and 796 men and 648 women died from cancer during the follow-up period.
Although anxiety could give rise to unhealthy behaviours, such as drinking alcohol and smoking to alleviate anxious feelings, when we accounted for these factors, we still found the same relationship. We also took into account a range of other important factors that could influence the association between anxiety and cancer deaths, such as physical inactivity, previous diagnoses of serious chronic diseases and social class – but the relationship held. There remains the possibility that we did not completely account for lifestyle factors or we may have missed including other factors which could influence the association, but this possibility exists for all research studies.
What can we do about it?
Our research shows that anxiety is not just an intractable personality trait, but could represent an early warning signal for something more serious that might occur down the road.
There are certain measures we can take, however, to alleviate feelings of anxiety and improve our overall health. The mind and body are intricately connected: one influences the other. Therefore, engaging in regular physical activity, getting enough sleep, drinking enough water and avoiding the prolonged use of light-emitting devices, such as smartphones, laptops, and television before going to bed are important for both mental and physical health.
Cognitive behavioural therapy is an effective psychiatric treatment option – and yoga and mindfulness meditation have also been shown to have positive effects on mental health, making you feel less stressed and anxious. According to research from Harvard, doing mindfulness meditation can actually change your brain structure and influence your levels of stress, which is a fascinating discovery.
Until we find out whether administering pharmacological and psychotherapeutic interventions to people with anxiety can contribute to improved health outcomes in the long term, knowing that anxiety could represent an early warning signal for poor health is a valuable step forward.
Olivia Remes (Department of Public Health and Primary Care) discusses new research which suggests that generalised anxiety disorder is associated with a two times higher risk for cancer deaths – but only in men.
Speaking at the launch of the £10million Leverhulme Centre for the Future of Intelligence (CFI) in Cambridge, Professor Hawking said the rise of AI would transform every aspect of our lives and was a global event on a par with the industrial revolution.
CFI brings together four of the world’s leading universities (Cambridge, Oxford, Berkeley and Imperial College, London) to explore the implications of AI for human civilisation. Together, an interdisciplinary community of researchers will work closely with policy-makers and industry investigating topics such as the regulation of autonomous weaponry, and the implications of AI for democracy.
“Success in creating AI could be the biggest event in the history of our civilisation,” said Professor Hawking. “But it could also be the last – unless we learn how to avoid the risks. Alongside the benefits, AI will also bring dangers like powerful autonomous weapons or new ways for the few to oppress the many.
“We cannot predict what we might achieve when our own minds are amplified by AI. Perhaps with the tools of this new technological revolution, we will be able to undo some of the damage done to the natural world by the last one – industrialisation.”
The Centre for the Future of Intelligence will initially focus on seven distinct projects in the first three-year phase of its work, reaching out to brilliant researchers and connecting them and their ideas to the challenges of making the best of AI. Among the initial research topics are: ‘Science, value and the future of intelligence’; ‘Policy and responsible innovation’; ‘Autonomous weapons – prospects for regulation’ and ‘Trust and transparency’.
The Academic Director of the Centre, and Bertrand Russell Professor of Philosophy at Cambridge, Huw Price, said: “The creation of machine intelligence is likely to be a once-in-a-planet’s-lifetime event. It is a future we humans face together. Our aim is to build a broad community with the expertise and sense of common purpose to make this future the best it can be.”
Many researchers now take seriously the possibility that intelligence equal to our own will be created in computers within this century. Freed of biological constraints, such as limited memory and slow biochemical processing speeds, machines may eventually become more intelligent than we are – with profound implications for us all.
AI pioneer Professor Maggie Boden (University of Sussex) sits on the Centre’s advisory board and spoke at this evening’s launch. She said: “AI is hugely exciting. Its practical applications can help us to tackle important social problems, as well as easing many tasks in everyday life. And it has advanced the sciences of mind and life in fundamental ways. But it has limitations, which present grave dangers given uncritical use. CFI aims to pre-empt these dangers, by guiding AI development in human-friendly ways.”
“Recent landmarks such as self-driving cars or a computer game winning at the game of Go, are signs of what’s to come,” added Professor Hawking. “The rise of powerful AI will either be the best or the worst thing ever to happen to humanity. We do not yet know which. The research done by this centre is crucial to the future of our civilisation and of our species.”
Transcript of Professor Hawking’s speech at the launch of the Leverhulme Centre for the Future of Intelligence, October 19, 2016
“It is a great pleasure to be here today to open this new Centre. We spend a great deal of time studying history, which, let’s face it, is mostly the history of stupidity. So it is a welcome change that people are studying instead the future of intelligence.
Intelligence is central to what it means to be human. Everything that our civilisation has achieved, is a product of human intelligence, from learning to master fire, to learning to grow food, to understanding the cosmos.
I believe there is no deep difference between what can be achieved by a biological brain and what can be achieved by a computer. It therefore follows that computers can, in theory, emulate human intelligence — and exceed it.
Artificial intelligence research is now progressing rapidly. Recent landmarks such as self-driving cars, or a computer winning at the game of Go, are signs of what is to come. Enormous levels of investment are pouring into this technology. The achievements we have seen so far will surely pale against what the coming decades will bring.
The potential benefits of creating intelligence are huge. We cannot predict what we might achieve, when our own minds are amplified by AI. Perhaps with the tools of this new technological revolution, we will be able to undo some of the damage done to the natural world by the last one — industrialisation. And surely we will aim to finally eradicate disease and poverty. Every aspect of our lives will be transformed. In short, success in creating AI, could be the biggest event in the history of our civilisation.
But it could also be the last, unless we learn how to avoid the risks. Alongside the benefits, AI will also bring dangers, like powerful autonomous weapons, or new ways for the few to oppress the many. It will bring great disruption to our economy. And in the future, AI could develop a will of its own — a will that is in conflict with ours.
In short, the rise of powerful AI will be either the best, or the worst thing, ever to happen to humanity. We do not yet know which. That is why in 2014, I and a few others called for more research to be done in this area. I am very glad that someone was listening to me!
The research done by this centre is crucial to the future of our civilisation and of our species. I wish you the best of luck!”
Artificial intelligence has the power to eradicate poverty and disease or hasten the end of human civilisation as we know it – according to a speech delivered by Professor Stephen Hawking this evening.
There would always be a first death in a driverless car and it happened in May 2016. Joshua Brown had engaged the autopilot system in his Tesla when a tractor-trailor drove across the road in front of him. It seems that neither he nor the sensors in the autopilot noticed the white-sided truck against a brightly lit sky, with tragic results.
Of course many people die in car crashes every day – in the USA there is one fatality every 94 million miles, and according to Tesla this was the first known fatality in over 130 million miles of driving with activated autopilot. In fact, given that most road fatalities are the result of human error, it has been said that autonomous cars should make travelling safer.
Even so, the tragedy raised a pertinent question: how much do we understand – and trust – the computers in an autonomous vehicle? Or, in fact, in any machine that has been taught to carry out an activity that a human would do?
We are now in the era of machine learning. Machines can be trained to recognise certain patterns in their environment and to respond appropriately. It happens every time your digital camera detects a face and throws a box around it to focus, or the personal assistant on your smartphone answers a question, or the adverts match your interests when you search online.
Machine learning is a way to program computers to learn from experience and improve their performance in a way that resembles how humans and animals learn tasks. As machine learning techniques become more common in everything from finance to healthcare, the issue of trust is becoming increasingly important, says Zoubin Ghahramani, Professor of Information Engineering in Cambridge's Department of Engineering.
Faced with a life or death decision, would a driverless car decide to hit pedestrians, or avoid them and risk the lives of its occupants? Providing a medical diagnosis, could a machine be wildly inaccurate because it has based its opinion on a too-small sample size? In making financial transactions, should a computer explain how robust is its assessment of the volatility of the stock markets?
“Machines can now achieve near-human abilities at many cognitive tasks even if confronted with a situation they have never seen before, or an incomplete set of data,” says Ghahramani. “But what is going on inside the ‘black box’? If the processes by which decisions were being made were more transparent, then trust would be less of an issue.”
His team builds the algorithms that lie at the heart of these technologies (the “invisible bit” as he refers to it). Trust and transparency are important themes in their work: “We really view the whole mathematics of machine learning as sitting inside a framework of understanding uncertainty. Before you see data – whether you are a baby learning a language or a scientist analysing some data – you start with a lot of uncertainty and then as you have more and more data you have more and more certainty.
“When machines make decisions, we want them to be clear on what stage they have reached in this process. And when they are unsure, we want them to tell us.”
One method is to build in an internal self-evaluation or calibration stage so that the machine can test its own certainty, and report back.
Two years ago, Ghahramani’s group launched the Automatic Statistician with funding from Google. The tool helps scientists analyse datasets for statistically significant patterns and, crucially, it also provides a report to explain how sure it is about its predictions.
“The difficulty with machine learning systems is you don’t really know what’s going on inside – and the answers they provide are not contextualised, like a human would do. The Automatic Statistician explains what it’s doing, in a human-understandable form.”
Where transparency becomes especially relevant is in applications like medical diagnoses, where understanding the provenance of how a decision is made is necessary to trust it.
Dr Adrian Weller, who works with Ghahramani, highlights the difficulty: “A particular issue with new artificial intelligence (AI) systems that learn or evolve is that their processes do not clearly map to rational decision-making pathways that are easy for humans to understand.” His research aims both at making these pathways more transparent, sometimes through visualisation, and at looking at what happens when systems are used in real-world scenarios that extend beyond their training environments – an increasingly common occurrence.
“We would like AI systems to monitor their situation dynamically, detect whether there has been a change in their environment and – if they can no longer work reliably – then provide an alert and perhaps shift to a safety mode.” A driverless car, for instance, might decide that a foggy night in heavy traffic requires a human driver to take control.
Weller’s theme of trust and transparency forms just one of the projects at the newly launched £10 million Leverhulme Centre for the Future of Intelligence (CFI). Ghahramani, who is Deputy Director of the Centre, explains: “It’s important to understand how developing technologies can help rather than replace humans. Over the coming years, philosophers, social scientists, cognitive scientists and computer scientists will help guide the future of the technology and study its implications – both the concerns and the benefits to society.”
CFI brings together four of the world’s leading universities (Cambridge, Oxford, Berkeley and Imperial College, London) to explore the implications of AI for human civilisation. Together, an interdisciplinary community of researchers will work closely with policy-makers and industry investigating topics such as the regulation of autonomous weaponry, and the implications of AI for democracy.
Ghahramani describes the excitement felt across the machine learning field: “It’s exploding in importance. It used to be an area of research that was very academic – but in the past five years people have realised these methods are incredibly useful across a wide range of societally important areas.
“We are awash with data, we have increasing computing power and we will see more and more applications that make predictions in real time. And as we see an escalation in what machines can do, they will challenge our notions of intelligence and make it all the more important that we have the means to trust what they tell us.”
Artificial intelligence has the power to eradicate poverty and disease or hasten the end of human civilisation as we know it – according to a speech delivered by Professor Stephen Hawking 19 October 2016 at the launch of the Centre for the Future of Intelligence.
Computers that learn for themselves are with us now. As they become more common in ‘high-stakes’ applications like robotic surgery, terrorism detection and driverless cars, researchers ask what can be done to make sure we can trust them.
A newly-developed form of transistor opens up a range of new electronic applications including wearable or implantable devices by drastically reducing the amount of power used. Devices based on this type of ultralow power transistor, developed by engineers at the University of Cambridge, could function for months or even years without a battery by ‘scavenging’ energy from their environment.
Using a similar principle to a computer in sleep mode, the new transistor harnesses a tiny ‘leakage’ of electrical current, known as a near-off-state current, for its operations. This leak, like water dripping from a faulty tap, is a characteristic of all transistors, but this is the first time that it has been effectively captured and used functionally. The results, reported in the journal Science, open up new avenues for system design for the Internet of Things, in which most of the things we interact with every day are connected to the Internet.
The transistors can be produced at low temperatures and can be printed on almost any material, from glass and plastic to polyester and paper. They are based on a unique geometry which uses a ‘non-desirable’ characteristic, namely the point of contact between the metal and semiconducting components of a transistor, a so-called ‘Schottky barrier.’
“We’re challenging conventional perception of how a transistor should be,” said Professor Arokia Nathan of Cambridge’s Department of Engineering, the paper’s co-author. “We’ve found that these Schottky barriers, which most engineers try to avoid, actually have the ideal characteristics for the type of ultralow power applications we’re looking at, such as wearable or implantable electronics for health monitoring.”
The new design gets around one of the main issues preventing the development of ultralow power transistors, namely the ability to produce them at very small sizes. As transistors get smaller, their two electrodes start to influence the behaviour of one another, and the voltages spread, meaning that below a certain size, transistors fail to function as desired. By changing the design of the transistors, the Cambridge researchers were able to use the Schottky barriers to keep the electrodes independent from one another, so that the transistors can be scaled down to very small geometries.
The design also achieves a very high level of gain, or signal amplification. The transistor’s operating voltage is less than a volt, with power consumption below a billionth of a watt. This ultralow power consumption makes them most suitable for applications where function is more important than speed, which is the essence of the Internet of Things.
“If we were to draw energy from a typical AA battery based on this design, it would last for a billion years,” said Dr Sungsik Lee, the paper’s first author, also from the Department of Engineering. “Using the Schottky barrier allows us to keep the electrodes from interfering with each other in order to amplify the amplitude of the signal even at the state where the transistor is almost switched off.”
“This will bring about a new design model for ultralow power sensor interfaces and analogue signal processing in wearable and implantable devices, all of which are critical for the Internet of Things,” said Nathan.
“This is an ingenious transistor concept,” said Professor Gehan Amaratunga, Head of the Electronics, Power and Energy Conversion Group at Cambridge’s Engineering Department. “This type of ultra-low power operation is a pre-requisite for many of the new ubiquitous electronics applications, where what matters is function – in essence ‘intelligence’ – without the demand for speed. In such applications the possibility of having totally autonomous electronics now becomes a possibility. The system can rely on harvesting background energy from the environment for very long term operation, which is akin to organisms such as bacteria in biology.”
S. Lee and A. Nathan, ‘Subthreshold Schottky-barrier thin film transistors with ultralow power and high intrinsic gain’. Science (2016). DOI: 10.1126/science.aah5035
A new design for transistors which operate on ‘scavenged’ energy from their environment could form the basis for devices which function for months or years without a battery, and could be used for wearable or implantable electronics.