Features

In the latest animation from Oxford Sparks, Dr Benjamin Brecht from Oxford's Department of Physics explores the 'miraculous' world of quantum physics, focusing on remarkable pieces of light known as photons.

Dr Brecht says: 'Quantum physics opens a window to a miraculous world, where extraordinary things happen that cannot be explained by our everyday experience. Things like quantum teleportation sound like science fiction, but they are being realised today in quantum laboratories. If we can harness these exciting phenomena, we can build new technologies that outperform their existing, classical counterparts. This vision of the future fascinates me and makes we want to add my small contribution to the pool of outstanding ideas.'

Oxford Sparks is a great place to explore and discover science research from the University of Oxford. Oxford Sparks aims to share the University's amazing science, support teachers to enrich their science lessons, and support researchers to get their stories out there. Follow Oxford Sparks on Twitter @OxfordSparks and on Facebook @OxSparks.

Jacinta O'Shea from the Nuffield Department of Clinical Neurosciences explains how stimulation of the brains of stroke patients can cause long-lasting improvements.

Every year thousands of people are left with debilitating symptoms after stroke. Perhaps one of the most striking is known as hemispatial neglect. This is when right-sided brain damage causes people to behave as though the left half of the world does not exist.

This problem arises when damage to the right parietal cortex disrupts the connections linking visual areas at the back of the brain with motor systems towards the front. The damage leaves the stroke survivor unable to voluntarily direct attention towards, and act on, visual objects in the space to their left.

Hemispatial neglect is very common, affecting many patients in the early months after stroke. Most recover over time, but about one-third do not, and suffer neglect as a lasting disabling condition.

The orthodox approach

To date there is no clinically established treatment, although researchers are developing promising methods to improve the condition. These methods focus either on changing patients’ brain activity or changing their behaviour.

One such approach is non-invasive brain stimulation. Damage to the right side of the brain causes the (undamaged) left side to become hyperactive. Suppressive stimulation of the (undamaged) left parietal cortex can reduce this hyperactivity. By ‘rebalancing’ brain activity in this way, neglect improves, but the effect lasts only for a few minutes.

Another approach is a behavioural therapy known as ‘prism adaptation’. Patients wear glasses containing prisms, which bend light, causing objects to appear to be shifted to the right. This results in a mismatch between where a patient sees an object and where they need to move their hand in order to touch that object. With training, patients learn to adapt to the prisms, by shifting their hand-eye coordination leftwards, towards the neglected half of space. This training improves many symptoms of neglect, such as postural imbalance and reading – but the benefit usually lasts only for 24 hours after training.

If either approach is repeated daily over several weeks the improvements can last for several weeks. However, this intensive repetition is time-consuming, labour-intensive, and costly.

A novel approach

Working with colleagues at the University of Lyon, France, we investigated whether it might be possible to use brain stimulation to improve how patients learn during prism adaptation, to make the therapy more efficient. In contrast to the traditional brain stimulation approach, which involves inhibiting brain activity in the left parietal cortex, instead we excited the left sensorimotor cortex, a brain region important for retaining newly learned motor skills. We reasoned that this might strengthen memory for prism adaptation training, which could cause longer-lasting improvements in neglect.

First, we tested this idea using tDCS (trans-cranial direct current stimulation), a mild form of non-invasive brain stimulation, in healthy volunteers during prism adaptation. We discovered that exciting the left sensorimotor cortex did indeed cause long-lasting memory of the adaptation task. Having established that this worked in healthy volunteers, we then carried out longitudinal case studies with three patients with hemispatial neglect. What we found surpassed our expectations.

In the early stage after stroke, these patients had shown improvements after prism therapy. But in the ‘chronic’ stage, over one year later, although the patients still adapted to prisms, this no longer caused any improvement. In different sessions in our study the patients performed prism therapy combined with real and fake tDCS. We then tested whether each patient’s neglect symptoms changed over time. We found that just one 20-minute session of real (but not fake) stimulation during prism therapy resulted in improvements in neglect that lasted for weeks to months and did not return to the baseline.

The patient was asked to distribute flowers equally around the garden. They are all clumped to the right, showing dramatic neglect of left space.

Our prediction that stimulation would strengthen the memory trace formed during adaptation, and cause neglect improvements to last for a long time, was proved correct. The duration of the improvement was surprising; moreover, it appeared to be cumulative, with each combined stimulation/therapy session building on the last.

Implications for stroke recovery

For these long-term ‘treatment-resistant’ stroke patients involved in the study, this was proof that they still have the capacity to make cognitive gains. We have established, for the first time, that it is possible to ‘switch back on’ or ‘reawaken’ plasticity in dormant brain circuits of patients suffering chronic neglect, more than one year after stroke, with the therapy gains lasting much longer than expected.

We’re now testing this in a larger group of patients in a randomised controlled clinical trial using a more intensive training regime. If the findings replicate, our approach will be a nice example of how we can take ideas from the neuroscience laboratory into the clinic to help improve stroke patients’ lives.

The full paper, 'Induced sensorimotor cortex plasticity remediates chronic treatment-resistant visual neglect', can be read in eLife Sciences.

This research was funded by a Royal Society Dorothy Hodgkin Fellowship to Jacinta O'Shea, with support from the Oxford Biomedical Research Centre.

Words by Jacqueline Pumphrey and Dr Jacinta O'Shea, NDCN.

Most people are aware of arachnophobia, but have you heard of arithmophobia?  Even if you haven’t, you’ve likely come across it.

Arithmophobia is the term for an irrational fear of numbers or mathematics – and it’s very common. So much so, that while people are usually too embarrassed to admit to finding reading or writing difficult, they feel more comfortable to laugh off their difficulty with numbers.

Dr Jennifer Rogers, Director of Oxford University Statistical Consulting of the Department of Statistics, has decided that it’s time all this changed, and is asking: ‘just what is our problem with numbers?’ As a leading statistician, she is confident that, not only is everyone capable of understanding how numbers work, but that we would be lost without them. Statistics can do so many things for you, influencing your choices without you even realising. Dr Rogers talks to Scienceblog about being a leader in her field, using statistics to improve people’s lives and why everyone is a secret statistician.

What is the one thing that you would like people to know about statistics?

I know some people find numbers scary, but they are hugely important and there for a reason.  Statistics illuminate, educate and inform our decisions. They shape our everyday decisions, from choosing shampoo, to where to live, and what airline to fly with - even though we may not realise it.

How do you think public understanding of maths and statistics can be improved?

We’ve all heard the phrase ‘Lies, damned lies, and statistics’. I think many people regard statisticians as liars, manipulating data in support of whatever story or agenda suits their purpose. But, any responsible statistician just wants to discover and tell the truth and statistics allow us to do that.

Statistics help government to make important decisions, For example, they can show which area has the best crime rate or hospital response time, and where it is decreasing or increasing in others. I always maintain that everybody is a secret statistician. If you were looking to buy a house you would compare one against others in the area; how close is it to a good school? Will it improve my commute to work? That’s statistical analysis - gathering data and using it to make decisions in our everyday lives.

Knowing how to ask the right questions and recognise flaws in what you’re being told is essential if you are to get the best out of life.

Why do you think maths has such a troubling reputation socially?

I think it is a real shame that it is not a social taboo to say ‘I can’t do maths.’ A lot of people in the public eye openly admit it now, almost to the point that it’s considered cool by some. That’s really disappointing. I understand that numbers are not always intuitive. Things like percentage increases and percentage point increases can be quite complex issues for people to get their head around. Everybody’s life can be protected and illuminated through numeracy. I think everyone should be able to walk into a shop and possess the skills to not be ripped off. Or, to be able to count change when they are getting into a taxi.

It’s also important to be able to evaluate and question what you see and read in the media. Knowing how to ask the right questions and recognise any flaws in what you’re being told is essential if you are to get the best out of life. For example, when you see an article that says eating bacon is going to increase your risk of cancer by 18%, that sounds really shocking - and like you should stop eating bacon now. But as a statistician, I can see that when you get into absolute numbers, actually, eating bacon isn’t as bad for you as that headline makes it sound.

What inspired the launch of the Oxford Statistical Consultancy?

There is such a wealth of expertise within the University, but it can go unnoticed and unused by the outside world, which is such a waste.  To me, it’s absolutely essential that there are accurate, properly applied statistics out there, helping us to understand more and to do things better. I’m determined that this unit will be a highly-tuned engine, powering businesses to new heights of creativity and success.

It is early days, and we have already worked with numerous and greatly diverse clients from healthcare providers to lawyers.  We’ve even worked on BBC1’s Watchdog for whom we evaluated the statistical probability of getting a middle seat at random, on a Ryanair flight.

Describe a typical working day in your life?

Because statistics are involved in just about everything, as Director of the Consultancy Unit, I get to be involved in a huge range of projects. I can be working on long-range forecasting, helping a supermarket to understand the best time to stock barbeques for hot weather. I also help healthcare providers to better understand how and why a disease occurs, mapping a patient’s pathway from diagnosis through to appropriate treatments, which is especially rewarding.

I do a lot of work developing clinical trials for new treatments. I’m involved in designing the trial and deciding the best way to assess the effectiveness of treatment and I’ll also advise my clients on the most suitable method of analysis.

People often say that I don’t look like a statistician, but what does a statistician look it?

What do you like most about your role?

The mathematician John Tooki said it best: ‘statisticians get to play in everybody’s backyards’. I think that sums up my job perfectly. I’m involved in so many different, fascinating and useful things - and I love it.

What is the biggest challenge in your work?

Well, I do get frustrated when there’s a bug in some computer programming code that takes half the morning to straighten out. But, seriously, communicating statistics is both the most rewarding and challenging thing about the job.

I often work with people who are not mathematically trained. So, I may have to translate quite complex statistical ideas for those who perhaps do not understand what I’m talking about at first, and it’s wonderful to watch their faces light up as the brilliance and, in my opinion, the beauty of the numbers becomes clear to them. Being able to communicate your findings so that decisions can be made is the most important part of the job, otherwise we are just analysing data for the sake of it. For example, I may have to explain to clinicians why a new treatment is a better choice for a particular disease than other options.

 What came first, your love of maths or statistics?

My maths teacher always said I was a natural mathematician, but, actually, I hated the subject at school. I thought I was rubbish at it. The standard number crunching exercises just bored me witless, but it seems to be all that’s learned about maths at school. It was only when I got to A-level maths that I really fell in love with the subject. I really began to see how statistics mattered, and the more I engaged with the figures, the more it all made sense.  Plotting and playing with raw data was when the subject cast its spell on me.  Ever since then I have loved applying mathematics to real world problems – and finding solutions.

What has your experience been as a woman in statistics?

Historically the field has been male dominated. People are always shocked when they meet me. They tell me ‘you don’t look like a statistician.’ But times are changing, membership of the Royal Statistical Society used to be predominantly male, but less so recently. However, I think academia is more challenging for a woman.  Fixed term contracts affect decisions about starting a family. You can find yourself unemployed while on maternity leave. Job security for young researchers needs to be addressed for it to be a viable long-term career option for women. Those are just some of the issues – I could go on, but this is a great place to start.

What are you most proud of?

I am really proud that my work can help enrich people’s lives. Sometimes as a statistician you can just sit in your office and plug in the numbers, never really seeing the outcome. Having the opportunity to go and see your work in action, and understand how it is influencing change, is profoundly rewarding. I remember going to a cardiology conference where my research was used to explain an alteration to a standard medical procedure.  Knowing that my work impacts real people at such critical junctures in their lives makes me feel inexpressibly proud.

As an expert on the literature of the Roman Republic and an avid viewer of the recent ITV show Love Island, Oxford classicist Dr Andrew Sillett was always going to try watching Bromans.

The new ITV programme is billed as a “gladiator reality show” which claims to send “eight modern-day lads back in time to see if they can cope with living and fighting like Roman gladiators”.

As he settled down to watch the first episode last week, Dr Sillett tweeted his reactions.

His tweets went viral – they were retweeted by dozens of other users and media outlets.

At the end of the show, he concluded: "10/10 will watch again."

“The interest my tweeting generated came as something of a surprise,” he tells Arts Blog.

“In all honesty, I didn't come to Bromans from an academic angle, it just followed on naturally from a summer spent in the company of Love Island. “All the responses I've received have been very friendly and supportive (which is hardly to be taken for granted on Twitter...).”

Andrew is evangelical about the importance of public engagement with a wide audience.

“I came to Classics from a bit of a standing start myself, as my school didn't offer Latin, Greek, Classical Civilisation or anything like that,” he says.

“Not that it was anything like Bromans that caught my interest ten years ago, that was a talk from Brasenose's Llewelyn Morgan (who bears only a passing reference to the gladiators of Bromans).

“Nonetheless I think it's undoubtedly important to be aware of what sort of contact the majority of people have with your subject.”

It is unlikely that many viewers of Bromans assumed it was a realistic depiction of Rome - but Dr Sillett says it did capture certain aspects of life in the Republic.

“In the run-up to Bromans airing I encountered a lot of snootiness in relation to the show's vulgarity, but I think that rather misses the point,” he says.

“Rome wasn't all marble, rhetoric and epic poetry, it had a popular culture of its own that was coarse, sweaty and physical.

“I think Bromans captures that as well as, say Ridley Scott's Gladiator; there's plenty ITV2 can teach us.”

Dr Sillett is a lecturer in the Faculty of Classics, specialising in the literature of the late Roman Republic and early Empire.

You can read more of his thoughts on Bromans here, and follow him on Twitter here.

This blog post originally appeared on the website of the American Geophysical Union (AGU). Its author, Lauren Lipuma, is a senior public information specialist and writer at AGU.

Wood from trees that fell into Arctic-draining rivers thousands of years ago is giving scientists a detailed look at how Arctic Ocean circulation has changed over the past 12,000 years.

In a new study, researchers used nearly 1,000 pieces of driftwood collected from Arctic shorelines since the 1950s to track Arctic sea ice extent and ocean circulation since the start of the Holocene.

Driftwood enters the Arctic Ocean from rivers. Some driftwood becomes frozen in sea ice, and floats on a raft of sea ice until the ice melts and the wood reaches shore. In the new study, scientists used driftwood samples to show the two main Arctic Ocean currents alternate dominance every few thousand years, with one current favouring sea ice formation and one favouring sea ice decline.

Arctic Ocean currents change over time, and insight into past changes in these currents can shed light on how the current rise in temperatures could affect sea ice extent. The new study's results help put the current Arctic sea ice decline into context and help researchers better understand the drivers of Arctic Ocean circulation and climate over time, according to the study's authors.

'The insights that can be gained from driftwood on Arctic shorelines give us a broader understanding into the Arctic Ocean, on a resolution in time and space that hasn't yet been possible,' said Georgia Hole, a geophysicist in the University of Oxford's Environmental Research Doctoral Training Partnership and lead author of the new study in the Journal of Geophysical Research: Oceans, a journal of the American Geophysical Union.

Arctic sea ice extent has declined steadily over the past three decades and reached a record minimum in 2012. Researchers want to know how Arctic sea ice grew and shrank in the past to understand what might happen in the future. Changes in sea ice are linked to changes in Arctic climate, and the Arctic is warming faster than any other region on the planet.

'Now we have satellite imagery for measuring current sea ice change, but it's hard to know what rapid changes were possible in the past,' Hole said. 'Increasing our knowledge of the scale and pattern of sea ice loss and growth in the Holocene helps to give us a much better picture of how the Arctic's sea ice responds during fluctuating climatic conditions.'

Sea ice records from before the satellite era are sparse, and scientists can't measure past sea ice extent directly. Scientists use proxies like ocean sediment cores to measure past sea ice extent, but ocean cores are expensive to collect and can only show changes in sea ice that happen over thousands of years.

Since the 1950s, researchers have used driftwood to gather data about past sea ice and, by extension, Arctic climate. Driftwood is less expensive to collect than ocean cores and can tell scientists about climatic changes on the scale of 250-500 years, rather than thousands of years.

When trees growing along the banks of the rivers that drain into the Arctic Ocean die, they fall into the water, and driftwood from these trees eventually flows into the Arctic Ocean. Some of this driftwood gets locked up in sea ice that forms in winter and rafted across the sea. When the sea ice melts in the spring, the driftwood washes up on distant shores, depending on where the prevailing ocean current takes it.

After collecting a piece of driftwood, researchers use radiocarbon dating to figure out how old it is and use the tree species to determine whether it came from North American or Siberian forests. Knowing the wood's age, place of origin, and where it was collected, researchers can then figure out how ocean waters were circulating during the time the wood was travelling and estimate how much sea ice was present.

In the new study, researchers collected all the driftwood data from previous studies that they could find – even those going back to the 1950s. They mapped the distribution of 913 driftwood samples and compared it to known records of past climate conditions to reconstruct a history of sea ice extent and ocean circulation over the entire Arctic Ocean during the Holocene.

The researchers found that sea ice extent went through several big changes over the past 12,000 years as the two main Arctic Ocean currents alternated in intensity.

They found evidence of more sea ice in the early Holocene, between 12,000 and 8,000 years ago, as the Beaufort Gyre dominated Arctic Ocean circulation. The Beaufort Gyre is a clockwise current that recirculates sea ice in the Arctic Ocean and enables ice to last for several years.

In the mid-Holocene, between 8,000 and 4,000 years ago, temperatures rose and the Transpolar Drift dominated. The Transpolar Drift moves water and ice in a nearly straight direction from Siberia westward toward Greenland and Svalbard. It tends to destroy sea ice and make it melt sooner. Finally, in the late Holocene, 4,000 years ago to the present, temperatures cooled again, the Beaufort Gyre strengthened, and more sea ice was able to circulate in the Arctic Ocean.

'Overall, the new study is giving us much more of an insight into these changes in Arctic sea ice, and the importance of these two circulation patterns in driving sea ice fluctuations over the past 12,000 years,' Hole said. 'With the state of the Arctic clearly being such an influential factor in the wider climatic system, increasing our knowledge of past sea ice dynamics is needed for revealing the Holocene Arctic climatic state and to investigate the Arctic system's climatic and biotic responses and feedbacks to increasing global average temperatures.'