The unsung story of amusia

image03We’ve all seen those contestants on shows like ‘X Factor’ or ‘Britain’s got Talent’ who are adamant they can sing, when the evidence unfortunately suggests differently. We ask ourselves how it is they can’t tell or we leap to the conclusion that it must be a set up. And, while I admit this may sometimes be the case, bear in mind there could also be a medical diagnosis to explain the situation. These individuals may have a condition known as amusia.

More colloquially called “tone deafness”, approximately 4% of the population suffer from amusia. This differs from the self-diagnosed 15–17% who believe they have the condition but are just poor singers – the difference being that poor singers are aware of their difficulty while true amusics are not. Amusics also tend to find music unpleasant to listen to, leading them to try to avoid situations in which they may be exposed – a rather difficult feat given the popularity and prevalence of music in modern society. Amusia can be congenital (i.e. the individual is born with the condition) or acquired (as the result of a brain injury or stroke). While amusia may seem less debilitating than other potentially socially isolating conditions such as dyslexia or dyspraxia, it can also cause an individual a great deal of stress, lead to social stigma and may affect an individual’s ability to process and learn tonal languages (e.g. Mandarin or Thai).

The term amusia was coined back in 1888 by a doctor called August Knoblauch, following the first diagnosis of the condition 10 years earlier. Nowadays, amusia is diagnosed by a set of six tests, collectively known as The Montreal Battery of Evaluation of Amusia (MBEA), which examine an individual’s musical ability for contour, scale, pitch interval, rhythm, meter and musical memory.

As yet, there is no consensus on the neurological causes for amusia but, a key feature apparent in those with the condition seems to be a deficit in fine-grained pitch discrimination (i.e. an individual’s ability to process a small change in pitch, such as a tone or semi-tone). Based on a number of studies which imaged the brains of amusics and non-amusics, two areas of the brain known to be involved in processing music appear to be affected in amusia – the auditory cortex (AC; especially the right AC) and the inferior frontal gyrus (IFG). These studies found a difference in cortical thickness of the AC and IFG, as well as a reduction in brain activity in the IFG of amusic subjects compared to matched controls. Amusics also showed reduced connectivity from the AC to the IFG (via a group of fibres called the arcuate fasciculus) which correlated with the degree of tone deafness of the individual, offering further evidence for the involvement of these areas in the condition.

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Whether someone with amusia can be “rehabilitated” or trained to improve their ability to process tone and to sing in tune is also up for debate. One small study in 2012 which provided five amusics with a 7-week course held by a professional singing teacher reported that four of the five subjects showed improved MBEA scores at the end of the study. However, whether the improvements were significant enough to warrant the time and resource invested into this study has been questioned.

It’s no secret that the term tone deafness is overused. But the condition, amusia, is a long-standing medical diagnosis which can have a significant effect on an individual’s social and educational life. Despite ongoing debate, the areas of the brain involved in music processing (the AC and IFG) differ both physically and in terms of activity in amusics compared with non-amusics. So next time X Factor hosts a “not so musically gifted individual”, I for one will hold my cynicism and consider a more medical reason before assuming it’s a set up.

Post by: Megan Barrett

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5 things politicians can learn from Scientists:

On the 7th of May 2015 the United Kingdom will hold a general election and party political campaigns are now in full swing. As a voter who is currently undecided, I’m fervently rifling through political literature and attempting to navigate jargon as I make my decision. But, as a scientist, I can’t help but feel that politicians aren’t making this decision easy for me. In a funny way, my world is pretty simple. In science, evidence and logic are key and we attempt to follow these to their conclusions. But this seems to be a far cry from the murky world of politics where evidence can be manipulated and jargon and rhetoric hold sway. So, as a public service, I present a list of five things politicians could learn from scientists.

1) There are lies, damn lies and political statistics:

6225881707_9afb3cc3bb_z(1)We live in a world abound with data – from traffic cameras to Google Analytics, computers the world over store vast amounts of information about our lives and the world we inhabit. This is no bad thing of course – knowledge has the power to make the world a better place. However, in unscrupulous or untrained hands, it can also deceive and manipulate.

Data is the currency that scientists deal in and, over the years, we have learned to handle it with care since things are often not exactly how they appear. But, what happens when big data and political aspirations collide?

Any trained orator knows that a light peppering of statistics can seal the deal during a debate, or at least muddy the water enough to breed uncertainty. But, how often do we hear similar sounding stats wheeled out by opposing parties and hailed as proof of very different ideals? Numbers can provide very important insights – but, depending on how you process the numbers, the same data can also give very different outcomes. Whether through honest errors in understanding (yes, numbers are tricky things) or by calculated deception, politicians often throw out dodgy stats in the hope of strengthening their argument and winning your vote – for a few examples see here.

In my opinion, the use of statistics in the current election campaign is doing little more than muddying the water and making the voters’ job significantly more challenging. How many people have the time or inclination to research every figure quoted? Statistics are very informative and key to most policies but, if they are to be used, politicians must also be clear about how the figures were obtained and why they may differ between parties.

2) The world isn’t black and white:

Wouldn’t life be great if all our problems had simple answers? For example, if we believed that all of our country’s financial and social problems could be solved by altering immigration laws, or if I could prepare for the upcoming ‘bikini season’ by simply popping a couple of magic diet pills. Sadly, the world is far from black and white, and oversimplification can often lead to misunderstanding and confusion.

Many voters may crave a ‘quick fix’ to our country’s social and economic problems, just like they may want to lose weight without diet or exercise, but that’s just not realistic! I want to know that policies have been formulated based on all available evidence and that – ‘God forbid’  – politicians are willing to recognise that these may not be perfect solutions and may even require modification in light of further evidence (see point 3). Although hyperbolic slogans may be appealing, it is well reasoned arguments based on clear, well explained facts that will allow voters to really understand the workings of the political machine and enable them to make an informed decision about their vote.

3) Changing your mind is nothing to be ashamed of:

How many times have you heard politicians being slated for performing ‘U-turns’? This phrase first gained media notoriety in the early 1970s when Prime Minister Ted Heath had to dump his free-market economic policy in the face of soaring inflation and rampant industrial action. This decision was viewed as an appalling show of weakness by the Tory right and, ever since, political U-turns have been widely derided by the media.

97338266_ed37f724df_zBut, during the current coalition government’s tenure, David and Co have reversed or rethought dozens of policies, from selling off Britain’s forests to taxing our favourite pastry-based snacks. Indeed, recent research by Ipsos Mori suggests that two-thirds of voters want a Prime Minister who acts mainly on the views and opinions of the general public when making decisions, rather than one who trusts solely in his own experience. In our dizzyingly complex world, I am heartened to know that policies are not set in stone and may be modified in the face of new evidence.

This is largely something scientists have been practicing for many years. In fact, all scientific theories are open for modification in the light of new evidence – many theories are widely accepted and would require extraordinary evidence to change but, given significant weight of evidence, anything is fair game. In the world of science, evidence is the one true king and this should also be true for politics. So, lets stop scoffing at political U-turns and be thankful when politicians admit to learning from their mistakes. In the words of Ghandi, “I am pleased when I change my mind because it shows that I have learned and grown wiser.”

4) Clarity is key:

As a scientist, I’m pretty used to sifting through technical jargon in scientific journals. And this is fine since, as a rule, this type of literature is aimed at scientists with a strong background in that particular field. However, as a science communicator, much of my time is spent agonising over ensuring that the material I communicate is accessible, truthful, representative and unambiguous. This is not an easy task but it’s 100% necessary if I want anyone (no matter what their background) to connect with the concepts I’m trying to communicate.

Sadly, I’m starting to think that many politicians enjoy being deliberately vague, evasive and inaccessible. My head spins with inscrutable statistics, vague and meaningless rhetoric, evasive noncommittal answers to seemingly simple questions and statements with little or no substance.

I recognise that, come May the 7th, the box I tick will be important for shaping the future of our country. So, is it too much to ask that politicians work hard to disambiguate their policies and structure their arguments around accessible facts and figures? In fact, sometimes the whole thing makes me question if any of the parties really know what they are talking about… As Einstein once said, “You do not really understand something unless you can explain it to your grandmother”

5) Lets move forward rather than shifting blame:

One political tactic which never fails to drive me mad is when, instead of discussing policies on important economic or social issues, parties waste time blaming their competitors for past failings or denigrating their current policies. My personal view on this campaign tactic came to a head in 2011 with the referendum on the alternative voting system, of which (after reading into it) I was in favour.

In the lead up to the referendum, I was saddened to see how much campaign material avoided the interesting facts behind the vote, choosing instead to plaster campaign literature with pictures of the recently disgraced Nick Clegg. This material seemed to be saying, ‘Nick lied to you about tuition fees, he wants the alternative voting system and he can’t be trusted so it must be a bad thing’. Yes, there was more to the ‘No’ campaign than just Nick Clegg’s face, but this message certainly played a role despite having no relevance to the issues being debated.

Again, in the lead up to this year’s election, I’ve seen my fair share of dodgy and largely irrelevant muck slinging, which I will be ignoring in favour of party policies – here are a selection of some of my personal ‘favourite’ dodgy campaign posters:

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That’s great Conservatives, thanks for the heads up…but I think I may just read through Labour’s policies and decide for myself if I think they will ‘wreck’ our economy…(still think this one is calling out for a Miley Cyrus reference somewhere)

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Have they now Labour? Can I see some proof that this would have been different under your government….or even better, why don’t you just tell me how you plan on making things better now.

Now, I’d be lying if I said that all scientists doggedly hunt out the truth without holding any personal grudges or undermining one another’s work – we’re all human. But, in general, scientists gain funding to further their research by explaining how their work will benefit society and increase our understanding of the world, not by slamming other lab groups or accusing them of bad science. And that’s really how things should be.

So, as an undecided voter, I hope politicians will hear my plea… If you want my vote, come to me with clear, well reasoned, policies. Don’t treat me like an idiot and try to gain my support through hyperbole and muck slinging… I don’t expect you to have all the answers, but I do want you to explain your political stance clearly, listen to my views, base your policies on the best available evidence and to not be afraid of changing your stance in the light of new evidence.

Post by: Sarah Fox

But, scientists are far from perfect! for an alternative view and some advice on what scientists could learn from politicians, check out the new post by Ian Wilson, one of our friends at the Scouse Science Alliance.

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Should science be on the agenda for the general election?

Those of you indexwho live in the UK will by now be unable to move without seeing some reference to the looming election. This year’s ballot results are thought to be amongst the most contentious in recent history. The hot-button issues on the agenda include the NHS, immigration and taxes. But what policies do each of the parties contending for seats in Parliament have regarding science and science funding?

Well, if you look at the key pledges in their manifestos, the answer is “not a lot”. The BBC has listed the top-line issues from the manifestos for many of the parties, including the five biggest UK-wide parties –  Conservative, Labour, the Liberal Democrats, UKIP and the Green Party. A quick search of any of these top-line topics does not pick out science or research. Whilst some parties may address the issue of science and science funding in their full manifesto, none of them appear to be campaigning on this issue.

lecture-hallThe closest thing any party regularly speaks about with regards to scientific policy is the environment. This BBC breakdown shows what each of the parties pledge with regards to the environment, with a particular focus on climate change. The parties also have stances on education, although many of the key points focus on primary and secondary school education alongside university issues such as tuition fees. However, they don’t tend to look further into postgraduate education such as master’s and PhD degrees. Only UKIP and the Welsh party Plaid Cymru make any reference to Science, Technology, Engineering and Maths (STEM) degrees in these at-a-glance manifestos. UKIP pledge to scrap tuition fees for those taking a STEM degree as long as they stay in the UK and pay UK taxes for five years after graduation. Plaid Cymru also offer support to STEM students who remain in Wales to study.

But does it matter that science is not included as part of the key election pledges? Surely science funding and postgraduate research is not as important to the country as the NHS, national security and welfare? Maybe not, but there are some arguments as to why it should be given a little bit more focus.

images1Firstly, a lot of science undertaken in this country is funded directly by the government. According to Research Councils UK, the combined spend of each of the government-funded research councils was about £2.8 bn on research in 2013-2014. Most of the remaining research expenditure comes from charities. Indeed, data released by the Association of Medical Research Charities in 2013 shows that the government spend on medical research was about £1.7 bn (split between the Medical Research Council and National Institutes for Health Research) while medical research charities spent nearly £1.3 bn in the same period.

Also, many of the issues at the heart of 2015’s manifestos are in some way related to science and research. The most obvious of these being healthcare, as medical research is responsible for finding causes and cures for a huge number of different conditions. This includes some topics that are very high on many party agendas, including cancer, dementia and mental health. Other issues include climate change, specifically policies on the controversial topic of alternative energy sources, with opinions varying wildly from different parties regarding fracking and nuclear power. Animal welfare is also high on several party manifestos, most notably the Green Party, who are aiming for a reduction of the use of animals in research.

imagesSome of the parties’ other policies could also have an indirect impact on science research and education. For example, UKIP’s plan to remove tuition fees for STEM graduates who stay in the country for five years after their degree ends may impact on people who intend on doing further study abroad. Talented graduates seeking further training abroad is not necessarily a bad thing; they will often gain expertise in new techniques, which they can then apply to research in the UK when they return. The Green Party’s policies on Genetically Modified Organisms (GMOs) and animal welfare would have a large impact on the use of these techniques in research. There have also been discussions about what would happen to science and research in an independent Scotland, which is a key aim of the Scottish National Party (SNP).

The science policy group ‘the Campaign for Science and Engineering (CaSE)’ wrote to several party leaders, to outline various policies regarding science in the UK. Amongst their requests were “[a] boost in government and business investment in UK research” and  “[ensuring] that the UK has a diverse pool of talented people … to drive our future scientific success”. Whilst each of the leaders replied to the letter, few appear to have translated the letter’s messages into their manifestos, at least not as a high priority. An exception is the Green Party, who directly reference a pledge to “double public spending on research in the next ten years”, although this does have caveats, as discussed above. An analysis by CaSE suggests that UK government expenditure on Research and Development as a proportion of GDP has been decreasing since 2003 and that this is causing the UK to lag behind other countries with regards to scientific output.

It would be foolish to expect that science funding and policy would be the key part of any manifesto for a general election. However, it is slightly disheartening to see that none of the major parties are focusing strongly on something that is at the heart of so many of their policies. Whoever ends up in government in May, the hope is that they continue to recognise the strength of scientific research in the UK and allow for it to continue and flourish.

For a look at the key pledges in the manifestos of each party, please see the BBC website.

Post by: Louise Walker

Disclosure statement: I am employed by a charity that funds medical research. The views represented here are my own and not that of my employer.

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Shooting the stars – Astrophotography as a hobby

About three years ago, I began to crave a hobby that would satisfy my curiosity about nature but not involve frontline scientific research (my day job). That hobby turned out to be astrophotography, an activity that is both fascinating and challenging regardless of how advanced you become.

After months of comparing different telescopes online, I finally settled on a medium-sized (120mm) refractor (containing a lens at the front), it being simple to use, tough and versatile. I quickly realised that there are many ‘amateur’ astronomers out there who are willing to spend thousands of pounds on equipment, often having multiple telescopes. I however, decided to perfect the use of a modest telescope with the hope of producing pictures that would only be expected from far more expensive kit.

After setting up my telescope and taking a whole array of different pictures, I found my interest moving towards deep sky objects (DSO). These are celestial objects outside our solar system such as galaxies and star clusters. They are normally very dim (often invisible to the naked eye) but, unlike planets, their apparent size (the size they appear from Earth) is typically large. By adding motors to my telescope, I can track these objects as they move across the sky. This allows me to take long-exposure photographs (10 minutes or more) revealing dim structure and colour which is not visible through the eyepiece during normal viewing.

However, I soon realised that my telescope had only limited accuracy when tracking DSOs. This caused DSOs to drift across the camera over several minutes, leaving ugly streaks of light on my pictures. So, my next upgrade was to add a guider; a device that monitors the movement of stars across the camera and sends a correcting signal to the telescope motors if alignment strays. This upgrade means that I can now get clean pictures that show DSOs in great detail – although the guider still needs a bit more work to avoid over-correction.

The pictures below show the culmination of years of small upgrades to my modest telescope. The first shows the Whirlpool galaxy (M51) while the second shows the great globular cluster in Hercules (M13), if you look carefully you may even spot some smaller galaxies lurking amongst the stars (these can be seen as small grey ‘smudges’).

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Whirlpool galaxy (M51) – a galaxy in the process of colliding with a smaller galaxy.

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The great globular cluster in Hercules (M13), a cluster of stars attracted together by their combined gravity.

Post by: Dr. Daniel Elijah.

Note: images were taken from the Galloway Astronomy Center in Scotland (one of the UK’s best dark sky sites)

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Ending Ebola: The 2014 Ebola Outbreak

What did we know about Ebola before 2014?  Fatal. Cruel. Limited to Sub-Saharan Africa.

Last year this all changed.

In 2014 an outbreak in Central Africa gained global media attention. Not only the largest epidemic of the disease to date, so far resulting in over 22,000  suspected cases and  nearly 9 000 deaths (WHO report 01/02/2015), it is also the first to impact the Western world. So where do we stand a year into the outbreak?

What is Ebola?

image1Ebola, first reported in 1976, takes its name from a river near one of the original affected areas.   Four different viruses are known to cause the disease humans, after being transmitted by wild animals.. The infection spreads between individuals through direct contact with bodily fluids.

Symptoms can take up to a month to develop – beginning as typical “flu-like” signs (fever, fatigue, muscle pain) before becoming more severe (vomiting, diarrhoea, organ damage, internal/external bleeding).  On average 50% of Ebola cases result in death, although the mortality rate can be as high as 90%, depending on the source.
Since being first identified, nearly 20 major outbreaks have been reported. Despite the ruthlessness of the disease, no cure or direct treatment has ever been developed and therapeutic plans tend to focus on supportive measures.

The 2014 Ebola outbreak

Although   first reported in late March, in fact it all started in December 2013 with the source a 1 year old boy in Guinea West Africa. A series of misdiagnosis meant it took 4 months for cases to be identified as Ebola.

image2By this time the virus had taken hold of Africa. Not only had the vicious disease already been suspected to have infected 80 individuals and caused 50 deaths, but cases had by now been  reported in other parts of West Africa.

The outbreak was by now too large to contain. Within 6 months the disease would spread beyond the continent, as far as Europe and the USA, becoming one of the most talked about global health epidemics of the 21st century.

What has the therapeutic impact of the 2014 Ebola outbreak been?

Late last year the Ebola epidemic was still rife. With the death rate at 70% and no direct treatment available, the World Health Organisation had no other plan except to take the unprecedented step of allowing the use of un-trialled treatments.

image3Now trials of several novel therapeutic plans are underway or about to commence in West Africa.

Another treatment involves the use of blood/plasma from recovered patients. Known as convalescent plasma therapy, the treatment is quick to develop, easy to implement (even in poor countries), with a potential bank of thousands of Ebola survivors to act as donors.
So while drug development may appear more beneficial for the long-term fight against Ebola, and indeed the effectiveness of several agents is currently being assessed in these areas, blood-based therapies may be more suited for the current outbreak.

Early 2015 also saw the beginning of two separate vaccination trials.

Vaccinations allow the body to build immunity against a specific virus, in this case Ebola. Both newly developed vaccines already passed Phase I clinical trials and have been shown safe for human use. Thus, February this year saw the start of Phase II and Phase III trials in West Africa. It is hoped these trials will determine the safety and effectiveness in a broader infected population and one day the working vaccine will become available internationally on a large-scale.

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Controlling the spread of Ebola

image5One of the main driving factors behind the outbreak last year was the confusion regarding diagnosis. Since Ebola symptoms resemble those of other diseases in Africa, such as malaria and typhoid, Ebola can often be misidentified – especially in areas where cases have never been reported.

To increase the odds of surviving, and limit the spread of the virus, those infected need to be rapidly identified, isolated and begin treatment as soon as possible. Tools which allow this to happen are currently being trialled in the most affected areas of Africa . One such tool involves low-resource kit that can identify the virus within 15 minutes.

Will the 2014 Ebola outbreak see the development of a direct Ebola treatment?

The unusual move of allowing un-trialled treatments creates the perfect opportunity to test the effectiveness of many new potential therapeutic plans quickly in a real-life scenario. However, these trials are not in any means controlled. So sadly even if a therapy is believed to be  effective, it will have to go through further trials before it is  deemed safe enough for widespread use – a process that can take several years.

In addition, the encouraging news that we have begun to slow transmission and are now in the process of ending the epidemic may have a negative impact on the tests. Already a trial of a potential Ebola drug in Liberia has been stopped because the case numbers have dropped to a level, at which the effectiveness of the drug cannot be clearly confirmed. .
After a year of the mass heartbreak caused by Ebola the seemingly unstoppable disease appears to be finally slowing. Although the trials of the new treatments have created hope for a solution, there is still plenty of work to do before we eradicate Ebola.

Post by: Claire Wilson

References

Ebola Virus Disease. World Health Organisation.

Ebola raises profile of blood-based therapy. Declan Butler, Nature.

Ebola vaccines, therapies and diagnostics.

New 15-minute test for Ebola to be trialled in Guinea. Wellcome Trust.

Wellcome Trust-funded Ebola treatment trial stopped in Liberia.

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Epigenetics – Putting the “epi” in epic

The latest craze in the world of science is to talk about epigenetics. You may have heard about it on TV or read about it in the newspapers, quite probably associated with some wonder cure or a way of shaking off those pounds without having to do anything.

Epigenetics is an extremely young area of interest in biology. It differs from good old-fashioned genetics in that it does not concern itself with the DNA sequence. Instead, it deals specifically with how chemical modifications made to the DNA and/or the proteins with which it associates (histones) can affect gene expression. It is an area of great interest because this regulation can have quite dramatic consequences, despite being relatively short-lived. These chemical modifications can be made and unmade very quickly, and thus ‘kick-in’ rapidly, yet can be triggered by simple changes in factors such as diet or exercise.

DNA is a long chain of individual molecules called nucleotides, which have three main parts: a deoxyribose sugar, a phosphate group and a base. There are four possible bases, which may be found in DNA (G, A, T or C) and certain sequences of these bases are used to encode proteins.

DNA molecules are enormous in length, as you might imagine given that they encode a human being. [Insert dubious statistic about length of DNA and distance to the Moon & back]. This presents a logistical challenge, because this information has to be readily accessible so that it can be read and copied to make proteins, yet it must also be stored away and protected within the small space of a cell’s nucleus.

The way in which nature has achieved this is by developing protein molecules around which the DNA can wind – the histones. Long chains of DNA wound around histone complexes coil and wind up even further, ultimately giving rise to the familiar ‘X’-shaped chromosomes that are seen during cell division (Figure 1).

Figure 1. Zooming out from DNA (1), to DNA wrapped around histones (2), through to an entire X-shaped chromosome formed from lots of DNA wrapped around lots of histones (5). Image source: Wikimedia Commons (Author: Magnus Manske). Image used under Creative Commons License 3.0)

Figure 1. Zooming out from DNA (1), to DNA wrapped around histones (2), through to an entire X-shaped chromosome formed from lots of DNA wrapped around lots of histones (5). Image source: Wikimedia Commons (Author: Magnus Manske). Image used under Creative Commons License 3.0)

 Figure 2. DNA wrapped around a histone (Image source: Wikipedia (Author: PDBot). Image used under Creative Commons License 3.0)

Figure 2. DNA wrapped around a histone (Image source: Wikipedia (Author: PDBot). Image used under Creative Commons License 3.0)

The phosphate groups carried within the backbone of the DNA give it a strong negative charge. Figure 2 shows how the protein has many positively-charged ‘tails’ reaching out towards the coiled DNA. These opposite charges attract to keep the DNA tightly wound and stable. When the time comes that some of this DNA needs to be accessed to be read, there are enzymes that attach modifications (e.g. methyl groups –CH3) to the protein’s ‘tails’ to remove their positive charges. These modifications are completely reversible and provide flexibility in regulating which genes can be activated at a given time.

Methyl group modifications can also be attached to the bases within the DNA. This is yet another element of epigenetics and it works in a similar way to histone modification. These groups recruit proteins that block the DNA-reading machinery from accessing the DNA.

Why is this important?

This system adds a sophisticated level of control to gene expression and regulation. This is part of what allows us, as multicellular organisms, to exist. Breakdown of this control can lead to disease and has been shown to have an important role in cancer. Harnessing the power of the ‘epigenome’ is of intense medical interest for the development of new drugs and in the use of stem cells.

The importance of epigenetics is emblemised by the field of stem cell research. In the stem cells of the embryo all genes are accessible and there is very little epigenetic control. This is important because these cells will go on to differentiate and form all of the many varieties of cells in the body. Such stem cells, with the ability to become different cell types, are said to be ‘pluripotent’.  But, as these stem cells differentiate and become more specialised towards a particular task, the level of epigenetic control tightens, effectively closing off whole portions of the genome that are irrelevant for a particular cell type.

In 2012 Sir John Gurdon and Shinya Yamanaka won the Nobel Prize in Physiology and Medicine for their “discovery that mature cells can be reprogrammed to become pluripotent”. They found that the introduction of just four different proteins that help regulate gene expression (transcription factors) is sufficient for the reprogramming of a mature cell into a pluripotent stem cell. These transcription factors serve to wipe the epigenetic slate clean, and actually erase modifications at the epigenetic level to reopen the genome.

These cells can differentiate into any other cell type, meaning that it might, one day, be possible to generate replacement cells and tissues might to treat a huge range of medical conditions including heart disease and Alzheimer’s Disease.

This post, by author James Torpey, was kindly donated by the Scouse Science Alliance and the original text can be found here.

Reference:
http://www.nobelprize.org/nobel_prizes/medicine/laureates/2012/

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Chocolate: the science of sweet

image1Rich, sweet and creamy with a sensuous ‘melt in the mouth’ texture. Chocolate is a guilty pleasure many of us share and, with Easter just around the corner, indulgence seems mandatory. But, what effect is our sweet tooth really having on our bodies and is there any scientific merit to claims that chocolate is actually good for us?

The medicinal use of chocolate has a long and rich history, with travel accounts and medical texts (dating from the 16th century) documenting a myriad of uses in the treatment of human disorders. These treatments range from the downright bizarre, to the infinitely plausible. For example:

Francisco Hernández (1577) wrote that pure cacao paste prepared as a beverage treated fever and liver disease. He also mentioned that toasted, ground cacao beans mixed with resin were effective against dysentery and that chocolate beverages were commonly prescribed to thin patients in order for them to gain “flesh.” William Hughes (1672) reported that coughs could be treated by drinking chocolate blended with cinnamon or nutmeg. While De Quélus (1718) wrote that drinking chocolate was nourishing and essential to good health. He said that drinking chocolate “repaired exhausted spirits,” preserved health, and prolonged the lives of old men. – For a more detailed overview of chocolate’s rich history, see here.

But do any of these claims hold water in the face of scientific scrutiny?

Chocolate: a way to the heart.

Dark chocolate and other cocoa products have, on a number of occasions, made the headlines as a dietary supplement and means to decrease blood pressure and modify other cardiovascular disease (CVD) risk factors (see here and here).

image2This line of research stemmed from observations among the Kuna Indian population in the san Blas Islands of Panama. Members of this population were seen to have particularly low rates of hypertension and CVD, coupled with an absence of age-related increases in blood pressure. Scientists theorised that theses unique medical traits were linked to high levels of cocoa intake amongst this group – On average Kuna Indians consume four 8-ounce cups of unprocessed cocoa drink per day!

One explanation for these findings is cocoa’s high flavanol content – which is thought to confer cardiovascular benefits through its effects on the circulatory system. Indeed, flavanol-rich cocoa may improve functionality of the bodies blood and lymph vessels and reduce various factors which may otherwise increase an individuals risk of CVD.

Alongside flavanols cocoa also contains an organic alkaloid compound called theobromine. The effects theobromine has on the body are pretty similar to those of caffeine, only slower to take effect – so perhaps a hot chocolate before bed time may not be a great idea. Alongside its caffeine-like properties, theobromine also acts as a cough suppressant, many ease the symptoms of asthma and, like flavinols, could improve cardiovascular health.

But, chocoholics beware, these findings do not prove that gorging on the brown stuff is actually good for our health. Firstly, the flavanol content of chocolate varies hugely depending on how the chocolate is processed. In fact, since flavanols are naturally bitter, these are usually thought of as unpalatable in the west and are generally reduced during the processing of our favourite chocolate treats. The cocoa powder consumed by the Kuna indians contains about 3.6% flavanols, while western chocolates range in their flavanol content – the highest being found in dark chocolate at 0.5%, while milk and white chocolate can sometimes be completely flavanol free. This means that, in commercially available chocolate products, the health benefits of flavanol are largely removed by the manufacturing process.

It’s also important to remember that most commercially available chocolate has a high caloric content and contains a significant amount of saturated fat and sugar. We know that excessive caloric intake can lead to some pretty adverse metabolic side effects (weight gain, diabetes perhaps even alzheimer’s disease) which probably negate any health benefits. This means that doctors would generally err against recommending chocolate as part of a healthy diet, with the possible exception of high quality dark chocolate.

So when it comes to a healthy body, the science of chocolate is not exactly black and white (or dark and milk) but, what about the effect it can have on the mind?

Chocolate on the brain:

in 1718 De Quélus wrote that chocolate can “repair exhausted spirits” and many people claim that indulging in the brown stuff can indeed be the perfect cure for low mood. But, how does chocolate effect the brain and, is the hedonistic pleasure of a good binge physical or psychological?

Chocolate consumption has been linked with a number of neurotransmitter systems, which play an active role in appetite, reward and mood regulation (including dopamine, serotonin and endorphins). However, there is currently insufficient evidence that these effects are specific to chocolate, or that they have an overall positive effect on mood.

340234_10100270433865775_1275067435_oInterestingly, although chocolate and junk food are regularly cited as the ‘go-to’ home remedy for malaise, extensive studies fail to find any real or lasting benefits to these binges. In fact, the opposite may be true, as often the guilt associated with a binge can leave sufferers feeling much worse!

So sadly, although a nice chunk of chocolate may provide brief pleasure and comfort, in the long term it’s more likely to prolong rather than abort a low mood.

So, chocolate is a mixed blessing. There’s almost certainly no harm in the occasional indulgence and, when it comes to high cocoa content dark chocolate it could even be beneficial. But, when it comes to our health, chocolate should definitely be considered a treat and not a lifestyle. That said, it won’t stop me enjoying my easter eggs this year!

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