February 2016 – The Brain Bank North West

Charity at home and abroad

February 21, 2016 by The Brain Bank North West

I am a Spanish scientist. I came to Manchester in 2007 to work as a postdoc in the Paterson Institute for Cancer Research. I have been working in oncology for the last 5 years so here I will focus on this, although what I’m about to speak about could also be extrapolated to many other causes.

It has always amazed me how committed people in this country are to fighting cancer. How so many adopt this fight as part of their daily lives; you see charity boxes in so many places (pubs, shops, coffee shops), people run, cycle, climb and swim all to raise money for cancer research. It seems so easy and so rewarding; to the point that it actually seems weird if you don’t get involved in something!

This leads me to question why this does not happen in my country? Is it because we are less supportive, are we so money orientated that we can’t give a penny for these causes or is it that that the Mediterranean diet protect us from cancer so much so that we don’t care or worry as much? Well, not the last one, of all EU countries Spain has the third highest rate of deaths due to cancer in people under 65. But what about the other two? Let’s think about them: are we Spanish people less supportive? I would say no. Spain is the world leader in organ donation and transplantation, which is pretty impressive since we are not a very big country. Not only that but we always show our support in the face of global catastrophe, organising call-in TV shows where people give money and which often raise many millions for the cause. So how about the second reason, are we a little bit tight with our money? As I said before, we are not. We as a country are happy to donate whenever we think people need it. We even broadcast TV shows where people can talk about their financial problems and others just call-in and donate money to them,offer them jobs or even give them a local rent free to start up a new business. So why is Cancer Research UK so much more successful than it’s Spanish counterpart (CRUK raised 661 million pounds in 2014 while it’s Spanish equivalent reached just 44 million)?

There could be several explanations for this. Firstly, when people donate organs their action will have a tangible effect on someone desperate for that organ, it will save a life right away. The same is true for donations made towards global catastrophes, when people donate money to these causes they believe that their money will go to help those whose lives have been damaged. But when they donate to cancer research they don’t see any instant benefit, people think it is a waste! Spain is not a leading country in cancer research so why are they going to donate to this cause? However, if people don’t get more involved we are never going to be a leading country. We have no charity shops and barely any money boxes dedicated to this cause. There are very few races organised with very little dissemination in the media. Among my academic friends working in Spain only one was even aware or the existence of World Cancer Day on the 4th of February.

I believe that if more people were to get involved this would encourage many others to do the same. Therefore, making advances in cancer research more likely and showing people a tangible outcome to their charitable donations. It just requires some compromise and support from different institutions and news industry. I hope that in the future this changes because not much has been changed in the last 9 years.

Post by: Cristina Ferreras

Making Metals (More) Interesting

February 13, 2016 by The Brain Bank North West

Metals are boring. Sure, they’re nice and shiny. And they’re definitely useful. But could you honestly, hand on your heart, say that the last time you saw a bit of metal you jumped for joy? Probably not.

The trouble is, we’ve been playing around with chunks of metal for so long that the novelty has worn off. You can melt down metal and create swords, axes and other cool things. That’s pretty neat, but it’s not exactly cutting-edge technology (see what I did there?). You can melt metals and mix then up to get alloys, which are awesome for jazz bands (brass instruments) and eating (stainless steel) among many other uses. Don’t get me wrong, I’m a great stickler for jazz and a big fan of the classic knife and fork combo, but neither of those things are particularly new.

Worse still, as a physicist working in the realm of optics whose job is to find things, shine light on them and see what happens, I find chunks of metal truly boring.

Fortunately for us optical physicists, lots of researchers in other fields were having a similar problem and suggested a solution: make things really really small and try measuring them again. The beauty of nanoscience is that conventionally boring materials can be made interesting again by studying them on the nanoscale (billionths of a metre). A recent example of this approach can be found in the world of carbon. Graphite is a pretty boring form of layered carbon atoms (as found in pencils), but reducing a piece of graphite down to a single layer (graphene) makes weird stuff happen.

Metal nanoparticles in stained glass windows: quite a bit more interesting.

What happens, then, when we shine light on tiny pieces of metal? It turns out we’ve had the answer right before our eyes for centuries without even knowing it. The brilliant colours we see in stained glass windows are caused by pieces of gold or silver a few tens of nanometres across. These pieces of metal absorb extra wavelengths of light which they wouldn’t absorb if they were of a more “conventional” size. Change the size of these metal nanoparticle by a few dozen nanometres (say, from 80 nm down to 50 nm) and the wavelengths of light they absorbed (and so the colour of the glass they are dispersed in) changes. This is all a bit weird, isn’t it? Compare a gold ring with a bar of gold, or a gold statue, and they all look to be the same colour – even though we’ve gone from something a few millimetres in length to something on the order of a metre. Yet change the size of a nanoparticle by a mere 10 or 20% and we get an enormous change.

So, what’s going on?

It all comes down to everybody’s favourite subatomic particle, the electron. Metals are made of regularly arranged atoms, this arrangement leaves one of the electrons (or more, depending on the metal) from each atom free to wander around the atomic lattice more or less as they feel. These delocalised electrons can be made to move in an ordered way by giving them energy. For example, by applying a voltage across a long, thin piece of metal (commonly known as a “wire”) the delocalised electrons will all flow along the metal in the same direction – this is electricity. But attaching crocodile clips to metallic nanoparticles is, as you can probably imagine, rather tricky. Instead we can induce collective motion in a nanoparticle’s delocalised electrons by shining light at it. In a nanoparticle, the delocalised electrons are confined to a small region, and they will strongly absorb certain wavelengths of light and convert this energy into collective oscillations. These light-induced electron oscillations are known as plasmons. The wavelength of light which excites these plasmons depends on the size of the particle but also on their shape and electron density (which in turn depends on the metal used).

The principle of plasmon resonances in metallic nanoparticles.

The fun doesn’t stop with stained glass windows, either. Tuning the properties of metal nanoparticles, placing them in arrays and combining them with other materials allows for all kinds of weird and wonderful properties with potential applications in biosensing, optoelectronics, cancer therapy, and possibly even invisibility cloaks (each of which will be discussed in subsequent blog posts). Best of all for a generation of bored metal-optics researchers, this cocktail of weird results means that metals have once again become interesting and will likely remain interesting for some time.

Post by: Philip Thomas

Webcam astronomy: simple but effective

February 8, 2016 by The Brain Bank North West

Over the past 4 years, I have been steadily assembling equipment for the purpose of photographing deep sky objects (DSOs). These are dim, sometimes large, diffuse cloudy patches when viewed using binoculars or a small telescope. Starting with the Andromeda galaxy (see below), I used a simple, long tube telescope fitted to a tracking mount (that tracks the DSO as it moves across the night sky). This allows a camera to collect light over a long period of time (often up to several hours) showing features that would otherwise be far too dim to detect with the naked eye.

The Andromeda galaxy (M31) taken by collecting over 2 hours of photographic exposures.

Although I personally find this type of astrophotography very rewarding, there are some major drawbacks. The first and most severe is how sensitive this type of photography is to unwanted light. Since photographing DSOs requires a really long exposure, any stray light from streetlights or the Moon simply washes out the object’s detail. The second is the sheer time it takes to collect the light to produce these types of photographs. The main issue is that as I take these long exposures (typically I take over 30 shots each lasting up to 5 minutes), any disturbance such as a gust of wind or nearby movement can cause the image to smear.

Mainly for these two reasons, I decided recently to branch into a different type of astrophotography – webcam astrophotography. Although I don’t have any pictures to show yet (I haven’t finished modifying the webcam yet, but watch this space!) I will briefly discuss the principles of this form of astrophotography and how it can be achieved with very limited equipment (and budget).

Put simply, webcam astrophotography involves taking a video of a bright night sky object (such as a planet or the Moon) and using the best frames of that video to produce a high quality image. There are several advantages to this approach. Firstly, since the object you are photographing will be bright, the exposures are short. This means that movement of the telescope will not cause image smear. In addition, the telescope mount does not have to track the night sky very accurately since each frame of the video is taken over a fraction of a second (normally 1/30s). Secondly, bright objects far outshine artificial light pollution, which makes this form of astrophotography very suitable for people living in towns and cities.

Photo of a bird with strong chromatic aberration caused by improperly focused violet light.

So, with a webcam and a cheap telescope mount, some impressive astrophotography can be achieved (see this link). However, I have neglected to mention anything about the telescope. When photographing bright objects overcoming chromatic aberration (CA) is a real problem. This optical aberration occurs when light being focused through a lens splits into its constituent colours and these colours focus at different points. The colour fringing effect caused by CA is shown on the right.

So, I decided t 20160130_093248 o use a telescope design known as a Maksutov-Cassegrain (modelled by my lovely fiancée Sarah) that avoids CA through an ingenious use of lenses and mirrors. There are three important advantages of using this telescope. (1) The light entering the telescope does not split into different colours (as mentioned). (2) Light is also neatly folded up so the actual telescope is conveniently small. Finally, although the telescope is short, it is capable of imaging at high magnification – an important feature if you wish to image small Moon craters or the great red spot on Jupiter.

A excellent image of Jupiter taken using a Maksutov-Cassegrain telescope and a cheap webcam. Photo credit: Dion from the Astronomy Shed.

In hindsight, perhaps I should have started my astrophotography hobby with webcam imaging; I would have saved a lot of time and money and not developed an irrational hatred of streetlights or the Moon!

Post by: Daniel Elijah