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The Lunar Reconnaissance Orbiter [LRO] is currently mapping the lunar surface. On board this 'robotic scout' is the Diviner, an instrument built and run by a team including Oxford University scientists.

In this week's Science two papers co-authored by Neil Bowles and Ian Thomas from Oxford University's Department of Physics report the latest findings from the instrument. I asked Neil what these results reveal about the lunar surface, how it formed and what it tells us about where to send future Moon missions...

OxSciBlog: Why is understanding lunar geology so important?
Neil Bowles: The lunar surface gives us a window into the evolution of the inner solar system. The evidence from the very early history of the Earth, such as impact craters, ancient volcanoes etc. have been virtually erased by the processes of wind and rain erosion, plate tectonics etc. These processes are not present on the Moon, so impact craters, ancient lava flows and other features are preserved.

By dating the rocks returned by the Apollo astronauts and comparing to the numbers and types of craters on the Moon, a time line for the formation of the lunar surface has been worked out and then used to date the surfaces features on the surfaces of other planets such as Mars and Mercury. The Moon underpins much of our understanding of how the Solar system formed.

OSB: What can the Diviner 'see' that other instruments cannot?
NB: Diviner is an infrared camera and so senses heat from the Moon's surface, a bit like thermal imagers used by search and rescue teams to look for people in collapsed buildings. However, Diviner is sensitive to a much broader range of temperatures and is the first instrument flown to the Moon that can measure the extreme changes in temperature you find on the surface.

For example, temperatures can get as high as about 120C during the day and as low as about  -150C during  the night, even colder at the poles. This information is essential for planning future exploration on the surface, both robotic and human.

Diviner is also sensitive to different types of minerals that make up the lunar rocks and soil. Different minerals 'glow' in different infrared colours, and by comparing these measurements with similar minerals made in our lab, we can learn about the surface composition of the Moon giving us insights into the processes that formed it. 

OSB: How has the latest data changed our view of the Moon's history?
NB: It has given us new evidence that there were multiple processes involving molten lunar rock on the surface of the Moon during its early history, some of which have led to very specific types of mineral being exposed on the surface. This in turn helps us to understand the processes that formed the crust on the Moon as we see it today and restricts the types of theories as to how the Moon formed in the first place.

For example, the new results suggest mechanisms that helped to form one particular region of the lunar surface called the Procellarum KREEP terrain early in the Moon's history. This region is geologically distinct because of the higher concentrations of radioactive elements found there. Heating by the decay of these radioactive elements, such as Thorium, raised the temperature of the crust, and combined with the fact that we think the lunar crust is thinner here they allowed the early, primitive surface to remelt and form a silica rich magma. This then floated back up to the surface as a plume, that once it solidified is now richer in rocks such as rhyolite than the surrounding region and this what was detected by Diviner.

If this interpretation is supported by future studies, it shows that after its initial formation, there were many different subsequent processes that led to the surface of the Moon as we see it today.

OSB: What future questions do we hope the Diviner can answer?
NB: As well as studying the composition of the lunar surface, Diviner measures the rates at which different parts of the surface heat and cool and from this it is possible to work out, for example, how rocky or dusty the surface is. Measurements of rock abundance may not sound very interesting, but are essential for choosing future safe landing sites and learning how impact processes work.

The other areas of high interest are the so called polar cold traps The Moon doesn't tilt on its axis as much as the Earth so its seasons are a lot weaker. There are regions at the lunar poles where the shadows cast by high crater walls mean that sun light never reaches the floor of the crater and the temperatures get very low (<-220C). These low temperatures mean that compounds such as water that would normally just boil away into space can be trapped for as ice for billions of years.

OSB: How will Oxford scientists continue to be involved in this work?
NB: We have been involved with the Diviner instrument from its proposal, manufacture and final testing on the ground. We are currently working on a wide range of lab experiments to measure the infrared response of different types of minerals under conditions similar to those found on the Moon, so that we can compare them with measurements made by Diviner.

We are also developing computer models of how heat flows through the top of the lunar surface and then gets measured by Diviner, again using our laboratory work to check the model and then apply it to the Moon.

The Oxford Diviner team includes Neil Bowles, Ian Thomas, Simon Calcutt and Fred Taylor. Diviner was built by by NASA/JPL and is led by David Paige at UCLA.

When he came to write his latest book Oxford University's Marcus du Sautoy decided he wanted to go beyond the printed page.

For The Num8er My5teries he created an 'app' that enables iPhone users to explore the ideas and games within the book and recently wrote for The Guardian on what apps can bring to books.

I asked Marcus about creating apps and how they can help to enrich the reading experience and communicate scientific ideas:

OxSciBlog: Why did you create a gaming app for the Num8er My5teries?
Marcus du Sautoy: The Num8er My5teries is a book which tries to get the reader actively involved in playing with the mathematics. The book grew out of the Christmas Lectures that I did in 2006 for the Royal Institution and Channel Five. The aim of those lectures was to find ways to playfully engage people in doing and understanding science.

I am a great advocate that mathematics is not a spectator sport and the best way to appreciate it is to play. It's one of the reasons that I have also been creating an internet maths school called mangahigh.com which aims to use online computer games to teach the GCSE curriculum.

The publication of the book has come at a time when publishers are exploring the power of apps to supplement and enhance the reading experience. The published book of The Num8er My5teries is jam packed with experiments and games so exploring the use of apps to enhance the playful character of the book seemed an exciting prospect.

OSB: What did you learn from making it? Any advice for other writers looking to do something similar?
MdS: The app we have produced is really just a first experiment both for me as an author and for the publisher. It combines games, videos of me talking about the book and excerpts from the book itself. So it is a very multimedia experience. I think these apps have a huge potential which still hasn't really been tapped.

I think it is important to recognise whether an app is really going to enhance the reading experience. It shouldn't just be a gimmick but should feel like an essential component of the experience. The book I have written stands on its own without any apps which I think is important. If resources permit I have got exciting ideas for pushing the project further.

OSB: What do you think writers can learn from videogames about communicating scientific ideas?
MdS: My experience with the internet maths school mangahigh.com is that if you get the game right you can deliver powerful scientific content together with a fun gaming experience.

I have a 14 year old who spends ages playing games online. He will repeat a level again and again until he has perfected it. Often this is what you need to do when you are learning new scientific ideas. The challenge is to get a good balance between a good gaming experience and learning objectives.

OSB: How do you think social media could help enrich the experience of reading a science book?
MdS: Tapping into the power of social media in doing mass scientific experiments I think is a really fascinating challenge. Galaxy Zoo here in Oxford has really done well in exploiting social media in doing citizen science. They have even developed an app so you can continue classifying galaxies while bored on The Tube!

Marcus du Sautoy is Oxford's Simonyi Professor for the Public Understanding of Science and a Professor of Mathematics at the Mathematical Institute.

If particles of dark matter are accumulating inside the Sun then we could use neutrinos to detect them.

A short article in this week’s Science, by Joseph Silk from Oxford University’s Department of Physics and Ilidio Lopes of the Instituto Superior Técnico, Portugal, suggests how this might be done.

They propose that the presence of dark matter in the Sun’s interior would cause a small but potentially significant drop in its central temperature. They calculate that in some scenarios an isothermal core – a region of constant temperature – should form, and this core could be picked up by neutrino detectors such as Canada’s Sudbury Neutrino Observatory [SNO].

“The existence of a dark matter isothermal core in the Sun would produce a unique signature written in the energies of solar neutrinos,” Joseph tells me.

“We calculate that the existence of dark matter in the Sun’s core could lead to a 4 per cent decrease in its central temperature and a 3 per cent increase in the central density of the Sun.”

Dark matter inside the Sun would decrease its central temperature by providing an additional way for redistributing the heat inside the solar core. The models developed by Joseph and Ilidio Lopes show that it should be possible to distinguish changes in the core produced by dark matter from those produced by other effects.

Professor Joseph Silk is based at Oxford University’s Department of Physics.

A study published in the journal PLoS One has found that taking daily high-dose tablets of certain B vitamins reduced the rate of brain shrinkage in people aged over 70 with mild memory problems.

All our brains shrink, especially with age. But the rate of shrinkage is seen to increase in those with mild cognitive impairment, and shrink faster again in Alzheimer’s, suggesting this is part of the disease process. So the observation that brain shrinkage rate can be reduced could be significant, but more work needs to be done to show that.

This finding is of interest because mild cognitive impairment is common – an estimated 1 in 6 people over the age of 70 have MCI – and it’s thought that up to half (so not everyone) go on to develop dementia within 5 years.

The result has been a large amount of media coverage, for example on BBC Online, The Times (subscription required), Daily Mail, and Daily Telegraph.

Despite some subeditors struggling to resist headlines suggesting beating Alzheimer’s or fighting dementia, some points should be stressed (which are actually being widely reported):

1)  It’s one reasonably small trial, although it does show a clear and very interesting difference in the rate of brain shrinkage over a two year period in those who took daily tablets of the combination of three B vitamins.

2)  A larger clinical trial, or certainly longer follow up of these people, is needed to see whether these particular B vitamins actually go on to slow any decline in cognitive ability and progression to dementia and Alzheimer’s before anyone can be confident they will have an effect.

3)  This was a study in people with mild memory problems who are not ill and are able to carry on their normal daily lives, not Alzheimer’s itself.

4)  The tablets included certain B vitamins – B6, B12 and folate – at a high dose; many times what you get in a well balanced diet. At these doses, they must be treated as drugs not just any dietary supplement, and should not be taken without medical advice as there could be side effects. Folate, or folic acid, at high doses and over long periods in some studies has been linked with cancer, for example, though the risk is low and shouldn’t worry anyone being advised to take it, such as pregnant women.

5)The researchers do not suggest people rush out and buy these B vitamins over the counter immediately on the basis of this one study, but call for that larger trial to be done.

The researchers held a press briefing in London communicating their excitement at these results but stressing all these points. Oxford University's David Smith, who led the study, talked about ‘a glimmer of hope’ with these ‘immensely promising results’ after recent failures of high-profile trials of Alzheimer’s drugs, and Helga Refsum said: ‘As a scientist, I would never be happy with the results of just one trial’.

And again, as David Smith says in our news story: ‘These are immensely promising results but we do need to do more trials to conclude whether these particular B vitamins can slow or prevent development of Alzheimer’s.'

Here’s what some other researchers elsewhere have said about the study that echo the interest in the work but offer some appropriate caution about how much we can take from this trial.

Paul Matthews, Professor of Clinical Neurology, Imperial College, London said: ‘This well-conducted study adds substantial new data to previous information suggesting that dietary B vitamins could have beneficial effects on neurodegeneration with aging.

‘Smith and his colleagues studied a mixed group of patients with mild cognitive impairment (MCI) and showed that 2 years of treatment with folic acid and vitamins B12 and B6 slowed rates of brain atrophy. Trends identified in their report suggest that the treatment could slow deterioration of cognition, but this was not demonstrated directly in this small study

‘It is important to appreciate that only some of the patients studied would be expected to develop Alzheimer’s disease; the results therefore should not be interpreted as providing evidence for a new treatment for this most common form of late life dementia.

‘The association between better treatment effects and blood levels of homocysteine - which can be elevated with a deficiency of B vitamins and an increased risk of stroke - raises the question of whether any benefits are related to effects on blood vessels supplying the brain.

‘Although the vitamins used are generally safe and inexpensive, the study should not drive an immediate change in clinical practice. Instead, it sets out important questions for further study and gives new confidence that effective treatments modifying the course of some dementias may be in sight.’ 

Dr Nicholas Timpson, MRC CAiTE Centre (Centre for Causal Analyses in Translational Epidemiology), University of Bristol said: ‘The trial based investigation of a series of homocysteine-lowering B vitamins (including folate and B12) and brain atrophy is of great interest.

'Authors note a reduction in the rate of atrophy in participants randomly allocated to treatment which is itself of great interest, however there are aspects of the work which need to be approached cautiously. These include comparison of observed effects to natural atrophy by age and the actual relationship between cognitive ability and the use of B vitamins. As to the latter of these, there is no direct analysis of cognition and whilst it is alluded to, the lack of this is a clear limitation.

'This work is good evidence of a causal relationship, but the reporting of mean effects in a study such as this does not guarantee impact at the level of the individual given adherence to the same vitamin regime.’ [David Smith points out to me that the study didn’t just report mean effects, but also divided out the results by baseline homocysteine level for example.] 

John Hardy, Professor of Neuroscience, UCL said: ‘The data is very interesting and I have seen it presented. Homocysteine is known to be involved in stroke-related diseases and so involvement in Alzheimer’s disease is plausible. But it is important to note that the study is rather small and needs replicating in a larger study.’ 

Chris Kennard, chair of the Medical Research Council’s Neurosciences and Mental Health Board said: ‘We welcome the findings of this MRC-funded study which bring us a step closer to unravelling the complex neurobiology of ageing and cognitive decline and holds the key to the development of future treatments for conditions like Alzheimer’s disease. However, we must be cautious when recommending supplements like vitamin B as there are separate health risks if taken in too high doses. Further research is required before we can recommend the supplement as a treatment for neurodegenerative diseases, such as Alzheimer’s.’

Figure 1 in the paper outlines the flow of participants through the two-year study. Drop out numbers at each stage are given with some of the reasons. There are some who drop out before the trial, some during, some were excluded, some were diagnosed with cancer, and two died. Of the initial 271 participants, 223 completed the two-year trial and cognitive tests.

But it does appear that there may be a high number of people in the two trial arms (vitamin tablets and placebo) not volunteering for MRIs. Only 168 people had the two MRI scans included in the study and which gave the paper’s main results. While the paper doesn’t describe the reasons for each case (I’m not sure how many papers do), there could be a number of reasons for this in what is an elderly group. It is after all a voluntary scan and some people may not, in the end, like the idea.

On asking David Smith, he adds further: ‘The important point is that in the trial we allowed for the fact that some subjects did not choose an MRI scan by including this in the initial minimization procedure. In other words, no bias was introduced.’

In the end, although these certainly appear promising results, we come full circle to where I started. So I’ll finish with Carl Heneghan’s last line in his blog at the Centre for Evidence-Based Medicine at the University of Oxford:

‘I'd call this an interesting result. But what is needed is a much larger trial, with a well defined clinically significant outcome. Ideally this would be progression to Alzheimer’s disease.’

Update 10 Sep: The Behind the Headlines section of the NHS Choices website has an analysis of the study here.

A new way of combining ultrasound images taken from different positions can result in sharper, better quality 3D images of the heart to help doctors make a diagnosis.

The new technique aims to improve on conventional 3D echocardiography which is not yet routinely used, partly because of problems with the quality of images produced and difficulties in imaging the whole heart.

A team of Oxford University biomedical engineers and cardiologists has developed a way of merging 3D data from ultrasound transducers placed in different positions on a patient’s body. The researchers recently reported in the journal JACC Cardiovascular Imaging that, in a pilot study of 32 people, this boosted the quality of good/intermediate quality images of the heart from 70% with existing methods to over 96%.

‘For the first time we’ve shown in a detailed clinical study how fusion of 3D data from different positions can improve the quality and completeness of the final image,’ Alison Noble of Oxford University’s Department of Engineering Science, a co-author of the report, tells me.

‘Our new technique saw significant improvements in the general image quality and the definition of features within the heart which should make it possible to spot even small abnormalities in, for example, the motion of the heart wall,’ adds Harald Becher of Oxford University’s Department of Cardiovascular Medicine.

The team's method is based on ‘voxels’ - 3D units of data similar to the 2D pixels on a TV screen. By matching similar-looking voxels of data from different positions it is possible to calculate the ‘best fit’ of a sequence of individual frames. This alignment is then applied first across ‘downgraded’ low-resolution images before these are ‘upgraded’ again to their original high-resolution – saving computation time.

‘This new approach is an exciting advance in echocardiography, as it enables us to see the sort of complete picture we weren’t able to before,’ Harald explains. ‘For instance, in this study a number of the participants were Oxford rowers with very large left ventricles which could not be imaged from a single position. By fusing our data we were able to produce accurate three-dimensional images of the entire heart within seconds.’

The team say these preliminary results are encouraging, although further studies are needed with larger groups of patients. The researchers hope their approach could lead to a greater use of 3D echocardiography in the future and are currently looking at how it could be combined with other heart imaging techniques, such as magnetic resonance imaging.

Video: Left and middle: 2D slices of conventional 3D echo images showing chambers of the heart. These four images were acquired from the same subject from four positions. Right: Resultant image by the fusion of four images shown on left and middle. Anatomical information and image quality is increased.

The Oxford University team included Professor Alison Noble, Dr Kashif Rajpoot, and Dr Vicente Grau of the Department of Engineering Science, and Professor Harald Becher, Dr Cezary Szmigielski, Saul Myerson, and Dr Cameron Holloway of the Department of Cardiovascular Medicine.

The research was supported by the EPSRC.