November 2014 – The Brain Bank North West

Meditation – science versus spirituality?

November 30, 2014 by The Brain Bank North West

Image courtesy of tiverylucky at FreeDigitalPhotos.net

The ancient eastern tradition of contemplation has slowly but steadily infiltrated the western world. But what is it all about and why are so many people taking it up?

There are quite a few ways to meditate. Some of them, e.g. yogic meditation called Kirtan Kriya, involve chanting of mantras: first aloud, then in a whisper, and then silently. This is sometimes followed by breathing and relaxing visualizations, e.g. forming mental images of light. Another popular type of meditation is mindfulness. Mindfulness means paying attention to the immediate experience with curiosity and acceptance. Do you know the feeling when you arrived home with no recollection of the route you have just driven because you have been thinking about the past or worrying about future? Mindful presence in the moment aims to teach us more conscious ways of living, as opposed to being on the ‘auto pilot’.

Contrary to what we might think, this type of meditation does not require controlling our thoughts or emptying our minds (although that would be nice, it is not going to happen straight away!). Rather, it involves observing your own experience (sensations, emotions and thoughts), noticing the thoughts and letting them go, just as you notice clouds in the sky.

Image courtesy of iosphere at FreeDigitalPhotos.net

Various forms of meditation appear to have a whole range of beneficial effects on our wellbeing. They reduce stress as well as symptoms of mental illness, especially depression and anxiety in a similar degree to medication. People suffering from chronic pain and stress-related physical illness also cope better. How exactly does meditation do that?

It seems that contemplative practice can change the functioning of our mind and body on several levels. Psychologically, switching off the automatic pilot helps us to pay more attention to our goals and values and act more in line with them. Mindfulness also increases self-acceptance and the ability to regulate one’s mood and emotions. This in turn seems to be underpinned by beneficial changes in the brain: people who meditate have increased activity, more grey matter and better pathways connecting the areas responsible for regulating emotions and attention.

Finally, some research shows that meditation affects our body on a physiological level: it might lower the level of the stress hormone cortisol, improve the response of the immune system, and even increase the level of a substance that protects our cells from deterioration (telomerase), thus slowing down the ageing process.

This sounds very promising, but how easy is it to scientifically investigate an ancient contemplative practice concerned with spiritual growth and lifelong development? One of the main problems is that many studies fail to use an appropriate comparison. For example, some studies compare people who have meditated for a long time with those who have no meditation experience. In such cases it is difficult to establish whether it is meditation that causes the changes in the brain and behaviour. It could be that certain personality features attract some people to meditation and could also be responsible for the differences in the brain.

Image courtesy of Photokanok at FreeDigitalPhotos.net

More and more often randomized controlled trials are used by researchers when studying meditation. In such studies a randomly chosen group of people is taught to practice meditation, and another group of people serves as a control, e.g. is taught relaxation techniques. This way we can be more confident that the differences between the groups at the end of the practice are not due to personality or factors such as relaxation. However, these studies tend to be quite short (e.g. they last a few weeks), whereas meditation is a skill developed over long periods of time.

Thus, having taken apart the skill of contemplating the present moment, science found that it can help us with stress, mental illness and pain. We can measure changes in the brain, mood and behaviour, but the more metaphysical aspects of meditation are difficult to capture. Personally I found practicing mindfulness very helpful in dealing with daily stresses. The quiet mind is an elusive goal, but meditation is about immersing in ‘being’, rather than ‘doing’. As the father of the western mindfulness Kabat-Zinn said ‘After all we are called human beings, not human doings.’

So, have you found your nearest meditation class yet?

Post By: Jadwiga Nazimek

References:

Teasdale et al. (1995) How does cognitive therapy prevent depressive relapse and why should attentional control (mindfulness) training help? Behav. Res. Ther. 33 (1) 25-39
http://www.sciencedirect.com/science/article/pii/0005796794E00117

Lavretsky, H. Et al. (2013) A pilot study of yogic meditation for family dementia caregivers with depressive symptoms: effects on mental health, cognition, and telomerase activity. Geriatric Psychiatry 28: 57-65.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3423469/

Sahdra et al., (2011) Enhanced response inhibition during intensive meditation training predicts improvements in self-reported adaptive socioemotional functioning. Emotion 11(2): 299-312.
http://psycnet.apa.org/journals/emo/11/2/299/

Droning On

November 25, 2014November 23, 2014 by The Brain Bank North West

Unmanned Aerial Vehicles (UAVs), or drones, are remotely or autonomously piloted aircraft. Whilst UAVs have recently been most associated with military applications, their use in the field of atmospheric science and environmental monitoring is rapidly growing, from the monitoring of carbon dioxide (Watai et al., 2006) and ozone (Illingworth et al., 2013) concentrations, to studying emissions at active volcano sites (Diaz et al., 2010).

Ground-based monitoring sites such as the Automatic Urban and Rural Network (AURN) in the UK, operated by the Department for Environment, Food and Rural Affairs (Defra), can provide measurements of surface level pollution concentrations. However, such fixed measurements are limited in their spatial coverage, as shown in Figure 1. Measurements from AURN are often used as validation datasets for regional air quality models such as the Met Office Air Quality Unified Model. Clearly, the inability of such sites to inform on a highly resolute scale can lead to a poor interpretation (and validation) of local environments.

Figure 1: Locations of AURN sites in the UK plotted on Google Earth. Pollution levels correspond to measurements taken on Friday 7th July 2013; data courtesy of Defra (http://uk-air.defra.gov.uk/).

An alternative to ground-based measurements is to use aircraft. However, such flight campaigns are not only expensive, but still also lack the required spatial resolution for many applications. Take Manchester city centre as an example: this area has a diameter of approximately 2 km, while the UK’s atmospheric research aircraft is able to travel at ~ 100 ms–1. This means that a typical 1 Hz instrument (i.e. one that is able to take one measurement per second) would only be able to make approximately twenty measurements during an overpass of the city. Large research aircraft are also restricted by the Civil Aviation Authority (CAA), which often means they are unable to fly around urban centres or within the lower boundary layer.

UAVs offer an ideal alternative at such scales, bridging the gap between ground-based and traditional airborne methods, with the potential to deliver detailed, high-resolution and precise measurements at the local scale.

Low Altitude, Short Endurance (LASE) UAVs are relatively simple to operate, with simple ground-control stations and control mechanisms, requiring only a small crew. Their small size means that they can be hand-launched (i.e. thrown) from a variety of terrains, and in the UK, UAVs with an operating mass of 7 kg or less are exempt from the majority of the regulations that are normally applicable to large and manned aircraft.

Figure 2: An RQ-4 Global Hawk flying in 2007 (Photo credit: Wikipedia).

High Altitude, Long Endurance (HALE) UAVs can be larger than many general-aviation manned aircraft and may fly at altitudes of up to 20 km or more on missions that can extend for thousands of km. The NASA Global Hawk, a well-known example of a HALE UAV (shown in Figure 2), has a wingspan of almost 40 m, and a length of approximately 15 m. The Global Hawk has been involved in a number of scientific campaigns since 2008 and has an operating altitude of 19,800 m and a flight endurance of over 30 hours, with a payload of ~750 kg.

Whilst UAVs undoubtedly get a bad rep because of their recent and well-documented use in military manoeuvres, with the continued miniaturization of highly accurate and precise sensors, the potential effectiveness of UAVs to make low-cost measurements, especially in remote, hazardous and politically unstable regions, continues to be the subject of much scientific and technological interest. And with Amazon recently getting in on the act, with Amazon Prime Air, their drone delivery service, it looks as though UAVs are here to stay.

Post by: Sam Illingworth

References:

DIAZ, J. A., PIERI, D., ARKIN, C. R., GORE, E., GRIFFIN, T. P., FLADELAND, M., BLAND, G., SOTO, C., MADRIGAL, Y. & CASTILLO, D. 2010. Utilization of in situ airborne MS-based instrumentation for the study of gaseous emissions at active volcanoes. International Journal of Mass Spectrometry, 295, 105–112.

ILLINGWORTH, S. M., ALLEN, G., PERCIVAL, C. J., HOLLINGSWORTH, P., GALLAGHER, M. W., RICKETTS, H., HAYES, H., LADOSZ, P., CRAWLEY, D. & ROBERTS, G. 2013. Measurement of boundary layer ozone concentrations on-board a skywalker unmanned aerial vehicle. Atmospheric Science Letters, 15, 252–258.

WATAI, T., MACHIDA, T., ISHIZAKI, N. & INOUE, G. 2006. A lightweight observation system for atmospheric carbon dioxide concentration using a small unmanned aerial vehicle. Journal of Atmospheric and Oceanic Technology, 23, 700–710.

How to ‘get’ yourself some Science

November 16, 2014 by The Brain Bank North West

Roll up! Roll up! The dawn of Open Access (OA) format has begun, thus making it possible (and indeed incentivised) for scientists to make their research freely accessible to all! This represents a historical breakthrough; research will no longer be the sole captive of subscription-only journals as was traditionally the case, with new guidelines ensuring that everyone can now access more research than ever, for free.

The OA policy published by Research Councils UK, which governs seven research councils with an approximate annual investment in research of £3 billion, suggests that making publicly-funded research available to the “general tax-paying public” is a central objective of this reform.

However, one could argue that merely making research available is not enough; research needs to also be accessible, i.e. easily understandable. It is my hunch that in some scientific fields the general public (myself included) would need a translator to be able to digest this material.

“Member of general public WLTM accessible Science w/GSoH. Seeking the uncomplicated and reliable. Willing to relocate. Will answer all.”

I could not illustrate this point more elegantly than to recall Marc Abrams’s speech (founder of the Ig Nobel Prize award for whacky research), at the British Neuroscience Association Festival of Neuroscience in 2012. In his talk he described a paper co-authored by his friend and colleague, the late Jerome Lettvin, the purpose of which was to amass and combine random technical jargon and formulae with the express purpose of writing nonsense. The outcome of this publication was a whirlwind of praise, invitations to speak and the receipt of many prestigious job offers: An illustration of the affliction of science. It seems that the more incomprehensible the content, the greater the acclaim – something that has contributed to the notion that to become a consumer of science one must be part of The Club. Happily though, this need not be the case as many researchers are now turning to blogging and the use of social media platforms to entice people back to the world of science in a friendly and, importantly, accessible way.

So how can we ‘get’ ourselves some science? Here’s just three of the ways I’ve found to be useful in finding and understanding new ideas outside of my field of interest, all of which require very little effort:

1. Read reliable blogs – if you’re already reading this then you’ve achieved point one on the list. Congratulations!

2. Follow scientists and science journalists on twitter – Science in 140 characters?! Yes Please! Perfect for those idol moments like standing in the lunch queue, or waiting for the bus; and often with links to more information if you want it. If you don’t know where to start, pick a scientist or science writer that covers broad topics, and see who they follow in turn. I saw a talk about science writing by Ed Yong (http://edyong.flavors.me/) whose blog is hosted by National Geographic (http://phenomena.nationalgeographic.com/blog/not-exactly-rocket-science/) and started following him. In turn I found similar writers whose style I liked. This method tends to cause your ‘Following’ list to grow exponentially, but fear not! You can use the ‘Lists’ option to organise the tweets you want to see at the appropriate times. I also comment on tweets and make sure to add my own hashtag such as #foodiegems or #neurogems. This effectively stamps the tweets I’m interested in for various reasons with my unique marker, and I can later retrieve all of these by searching for that hashtag. No, it’ll never be trending, but it’s a cool way to organise info you want to come back to. Remember to make sure it’s a very individual hashtag or else you’ll find yourself scrolling through unrelated tweets.

3. Go to events! There are a number of affordable or FREE public science events around Manchester, which are usually fairly informal and laid back. Combine a beer (or non-alcoholic beverage) with Science at Café Scientifique (http://www.cafescientifique.manchester.ac.uk/), or if you missed the Pint of Science Festival in May this year (http://www.pintofscience.com/) put it in your diary for 2015! Alternatively if you think that watching an awkward academic explain their topic and combine this with stand-up (and/or other performing arts), keep an eye out for Bright Club Manchester events (http://www.manchesterbeacon.org/members/172/Bright-Club-Manchester). And don’t forget SciBar on the last Monday of every month, held at The Salutation Pub, organised by Manchester Metropolitan University (https://www.theunionmmu.org/your-space/the-salutation/).

It’s clear that science can be somewhat out-of-reach at times, and that admirably, OA will provide a partial solution to this. However, in its current form it is still a little way off providing a fully viable solution to those of us from the general public who wish to engage with more science on a day-to-day basis. Access to science might be improving, but ‘getting’ it still needs a little work from all parties.

Post by Gemma Barnacle

Manchester mathematicians give us all a chance to play the Imitation Game.

November 12, 2014November 9, 2014 by The Brain Bank North West

Let’s get the shameless plug out of the way first…

On November 14th, `The Imitation Game’ – a biopic about the codebreaker, mathematician and computer scientist Alan Turing, and starring Benedict Cumberbatch in the lead role – is released in cinemas. To promote the film, StudioCanal together with the School of Mathematics at the University of Manchester are running a cryptography competition based on Alan Turing and set around Bletchley Park. Prizes include film posters signed by the principal cast, soundtracks, DVD bundles, day passes to Bletchley Park, etc. The competition, which runs until November 28th, is open to everybody and can be found here.

Ok, advert over, so let’s talk about how and why we got involved in this…

Starting in 2012, the School of Mathematics at the University of Manchester has been running `The Alan Turing Cryptography Competition’. Unlike the Imitation Game competition, this is open only to schoolchildren in Year 11 or below. We’re aware that many children are turned off mathematics at a young age as they equate it with `doing hard sums’ and often don’t get to see that it’s actually about creative problem solving and logical thought. The competition is a way of addressing this. In fact, we deliberately make sure that the codes in the competition can be solved bare-handed (without recourse to computer programming or even GCSE-level mathematics) – provided that you can `think-outside-the-box’!

Each year the competition is themed either around some aspect of Turing’s life and work or the University, often incorporating perhaps less-well-known facts. One example (and one which we revisited for the Imitation Game competition) is that, in 1940, whilst Turing was working on cracking the Kreigsmarine Enigma machine at Bletchley Park, he was worried that if the Germans invaded the British Isles then sterling would become worthless. He converted his life-savings into silver ingots and buried them somewhere near Bletchley. Unfortunately, he subsequently forget where – and they are (presumably) still there, likely buried under a housing estate in Milton Keynes!

We also incorporate some classical ideas or other stories relating to cryptography into the competition. One code involved solving crosswords. This was inspired by the fact that, in 1941, the Telegraph (at the behest of the War Office) organised a cryptic crossword competition; those who did well were recruited as codebreakers at Bletchley Park. Another code mimicked a `numbers station’ (a numbers station is a shortwave radio broadcast often consisting solely of a computer-generated voice reading out sequences
of numbers; they are believed to be broadcasts from governments to spies in the field).

One reason I believe that the competition has been so successful is that cryptography is a great way to bring mathematics alive. The abstract thought processes that are needed to crack a code are very reminiscent of the skills needed to be a professional mathematician. It’s also easy to relate cryptography to the real world: from codebreakers in the 1940s slaving away late at night to crack the Enigma machine so as to defend Britain, through Turing’s own tortured personal life, to how cryptography is used by all of us whenever we send secure information (credit card details, for example) across the internet.

The Imitation Game Cryptography Competition runs until Nov 28th. Next year’s Alan Turing Cryptography Competition starts in Jan 2015, http://www.maths.manchester.ac.uk/cryptography_competition

Post by Dr. Charles Walkden

Winter: a SAD time for some

November 2, 2014 by The Brain Bank North West

We all feel a little ‘blue’ over the winter period. With the days getting shorter and cold setting in, it’s no wonder we find it harder to be our usual ‘perky’ selves. But for some people, this feeling is far more extreme. For those with seasonal affective disorder (or SAD for short), the winter months each year mean a period of significant depression, fatigue and a loss of interest in the activities they would usually enjoy.

Despite some ongoing cynicism, SAD is classified as a medical condition by the American Psychiatric Association – though the individual must already be diagnosed with a major depressive or bipolar disorder and should have experienced SAD symptoms for at least two consecutive years [1,2]. What is interesting about SAD, however, is that in contrast to the typical symptoms of depression, individuals with SAD often experience hypersomnia (an increased desire to sleep) rather than insomnia and a heightened rather than reduced appetite, resulting in weight gain [1,2].

So far there is no consensus as such on the causes of SAD but it is generally agreed that seasonal changes, primarily shorter light periods and lower levels of environmental light available, play a significant part. This is supported by the use of light therapy to successfully treat up to 70% of individuals with SAD [1]. But how does a lack of light translate into SAD?

One of the major theories relating light to SAD involves our circadian system, known more anecdotally as our ‘biological clock’. This system controls our daily (and seasonal) cycle, dictating when we feel alert and sleepy, when we get hungry, and being responsible for the onset of hibernation in certain (some may argue more sensible) animals. Our circadian system responds to environmental cues, principally light, using these signals to sync our body clocks to the outside world through the release of chemicals which indicate when it is most appropriate to eat, be active or sleep [3]. In individuals with SAD, this delicate and complex system is believed to be disrupted, leading these people to become ‘out of phase’ with their environment, upsetting their sleep and eating patterns and causing them to become depressed.

Much of the research behind the circadian theory to date has focused on melatonin, one of the key components of our circadian systems and the chemical responsible for making us sleepy. Under normal circumstances, our bodies release melatonin at night and stop in the morning in response to light. This allows us to sleep when it is most appropriate. In some people with SAD, however, this cycle appears to be out of sync, with melatonin being released either earlier or later than usual [4]. By normalising this release pattern using either light therapy or the administration of melatonin itself, it may be possible to relieve the symptoms of SAD, and a number of studies have been carried out which support this hypothesis [3,4].

A second theory linking light and SAD looks at the eyes, or more specifically the retinas, of people with SAD, suggesting a lower sensitivity of these structures to light. Under normal circumstances, our retinas increase their sensitivity in response to low light conditions, i.e. dark winter days. In individuals with SAD, however, this may not happen [2]. Studies designed to test retinal function by measuring the electrical response of the retina to light have found that the retinas of some people with SAD are less responsive to light in the winter compared to the summer and in relation to healthy controls, lending support to this theory [3,4].

The third and final theory we’ll discuss in this article involves a family of signalling chemicals found in our brains, known as monoamine neurotransmitters. Members of this family, namely serotonin and noradrenaline, are known to affect our mood, eating and sleeping habits, making it logical to suggest they may be involved in the biological basis of SAD [1]. They also appear to respond to light availability and time of year. Our serotonin levels, for instance, are higher in summer than winter [3,4]. In some people with SAD, levels of serotonin and noradrenaline seem to be lower than in healthy controls. Increasing these back to the norm using either light therapy or drugs which promote serotonin or norepinephrine production has been shown to improve mood in these individuals and relieve their SAD symptoms [3,4].

As is so often the case with medical conditions, particularly those involving our mental health, our understanding of the causes behind SAD is still somewhat hazy. However, irregular responses to low-light environments found in SAD sufferers, whether it be through abnormal melatonin production disturbing their circadian systems, less sensitive retinas, or atypical levels of neurotransmitters, does seem to be a major factor. Both time and further investigation are needed to understand fully the biological causes of SAD and improve therapy options. Nevertheless, for those suffering with this condition, rest assured there is light at the end of the tunnel (do excuse the pun).

Post by: Megan Barrett

References
Gupta A, Sharma P, Garg V, et al. Role of serotonin in seasonal affective disorder. Eur Med Pharmacol Sci 2013; 17: 49–55.
Roecklein K & Wong P. Seasonal affective disorder. In: Gellman M & Turner J (eds.). Encyclopedia of behavioural medicine. New York: Springer; 2013. p1722–4.
Danilenko K & Levitan R. Seasonal affective disorder. In: Schlaepfer T & Nemeroff (eds.). Handbook of Clinical Neurology, Vol. 106: Neurobiology of psychiatric disorders. 3rd series. Amsterdam: Elsevier; 2012. p279–90.
Rohan K, Roechlein K, Haaga K, et al. Biological and psychological mechanisms of seasonal affective disorder: a review and integration. Curr Psychiatry Rev 2009; 5: 37–47.

Bovine tuberculosis in the UK- the bigger picture

November 2, 2014 by The Brain Bank North West

Bovine tuberculosis (bTB) is a disease that seems to gather a lot of attention in the popular press, especially the highly controversial badger culling trials in England and Wales. But what is this disease, and why is it so important in this country?

The disease

Bovine TB is caused by the bacterium Mycobacterium bovis (M. bovis), a very close relative of the principle cause of human TB, M. tuberculosis. It predominantly infects cattle, but perhaps not surprisingly can also be transmitted to, and cause disease in, people making it a zoonosis (a disease which can be transmitted readily between humans and animals). In both cases the resulting disease is very serious; symptoms include persistent cough, weight loss and fever of increasing severity over weeks and months, ultimately leading to death if no intervention is applied.

Mycobacteria — A high magnification image of mycobacteria captured using an electron microscope (CDC)

Historically, human infection with bTB has been a very serious problem in the UK; records from the 1930s suggest it accounted for at least 16,000 deaths in that decade alone! The major route of transmission at the time was through people drinking the milk of infected animals. Widespread implementation of pasteurisation (the process of heat-treating milk to kill disease causing bugs) from the late 1930s onwards, combined with the routine testing of cattle for the disease and meat hygiene inspection, virtually eliminated M. bovis as a causative agent of human TB in the UK. However, in many other parts of the world, particularly developing countries (where such measures are sometimes harder to implement) human infection with bTB remains a very serious issue, with millions of people still at risk across the globe, as demonstrated by figures published by the WHO on human TB; it is estimated that in the 1990s, TB accounted for 30 million deaths worldwide, of which M. bovis is believed to have been the causative agent between 10 and 50% of cases in developing countries, the areas where TB is a particular problem¹.

bTB in cattle: an ongoing saga

M. bovis is a very slow growing bug, with disease taking several months to become obvious physically. Unfortunately, during this time infected animals may remain within their herds, potentially spreading the disease with other individuals. The slow growing nature of the bacteria also makes it incredibly difficult to kill. As a consequence in the UK, and many other countries where bTB is a problem, the treatment of infected animals is not considered an option. Instead a “test and cull” policy is employed, whereby animals are tested for the disease and immediately slaughtered if found to be positive.

The test used in cattle is very similar to that used to detect TB in people (some of you may remember having this procedure as a child). It works by injecting a small amount of material taken from the M. bovis bacteria (called the “antigen”) into the skin of the cow. Animals that are actively fighting infection will react strongly to this material resulting in a large swelling in the area; this inflammation indicates that they are bTB-positive. At present all cattle in England and Wales are tested at regular intervals, typically every 1-4 years depending upon the current level of disease in the area. Farms where positive animals are found are placed under restrictions, whereby no animals may be moved off the premises until the farm’s ‘TB-free’ status is restored, in an attempt to stop the disease being spread through the movement of infected cattle to other farms.

Testing was originally introduced in the mid 1930s on a voluntary basis, but became compulsory from the 1950s across the entire country. There was initially a rapid reduction in disease prevalence, and throughout the 1960s and 70s it was all-but eradicated. However, from the mid-1980s onwards, and for reasons which are still not fully understood, the disease underwent a resurgence and the situation today in parts of the UK is as bad as it ever has been; between 2000 and 2010 over 250,000 cattle were slaughtered as a result of these strict measures at an estimated cost to the UK taxpayer of £500million. Currently Scotland is the only part of the country considered to be free of the disease, and while the most recent government figures suggest disease prevalence is slowly decreasing, whether this trend will continue, as hoped, remains to be seen².

Completing the picture

One reason that bTB has continued to be an issue after so many decades is that there are a great deal of unanswered questions in connection with its resurgence and transmission. As with many diseases, more discoveries simply raise more questions- none more contentious than the issue of badgers.

It is known that badgers can act as a “reservoir host”, meaning that they are able to carry M. bovis and transmit it back to cattle. What is less clear is the significance badgers play in spreading the disease, and whether or not controlling badger populations would help in controlling bTB in cattle.

In the autumn of 2013, badger-culling trials were commenced in 2 areas of England in an experimental effort to quantify whether any benefit is afforded through a reduction of the disease in cattle. However, these trials were abandoned early in 2014, since it was not possible to achieve the target of culling 70% of the badger population; the minimum figure believed to be necessary to reduce overall disease prevalence. This is a hugely disappointing outcome, as it means that badgers have been culled for no beneficial reason, and the trial has therefore provided no new information as to whether culling badgers helps control disease in cattle- a situation neither pro nor anti-badger culling campaigners can possibly be happy with.

In addition to the link with badgers, there are many other aspects to bTB biology that are not fully understood. Two notable examples of this include the recent and rather startling news that domestic cats have infected their owners with M. bovis. This not only underlines the issue of public health surrounding bTB, but also demonstrates the variety of species which are capable of carrying infection, potentially further muddying the waters as regards reservoir host species and disease control³. A second example is that of recent research from the Department of Infection Biology, at the University of Liverpool, which has shown a new experimental link between bTB and liver fluke, a common parasitic worm that infects livestock across the UK. In this study researchers found that liver fluke were capable of ‘modulating’ a cow’s immune system, meaning they can in effect ‘turn down’ the immune response in an effort to avoid being killed by it. This appears to have knock-on consequences for the cow, since it also reduces the animal’s ability to fight off other infections like bTB. Additionally, dampening of immune responses has been shown to reduce the sensitivity of the bTB test, meaning that in areas where there is a lot of liver fluke, bTB may go un-diagnosed for long periods. This could help explain in part why certain areas of the country remain in the clutches of bTB despite our best efforts⁴.

Clearly then, there is a much more to bTB than the press would have you believe. The next time you see or read an article in the news about the rights and wrongs of badger culling, remember this is only one small part of a much bigger picture. For example, would the public feel differently if the government was pursuing the control of feral cat populations in an attempt to reduce the risk of TB infection in people?

This post, by author John-Graham Brown, was kindly donated by the Scouse Science Alliance and the original text can be found here.

Citations:

1. Statistics worldwide: http://wwwnc.cdc.gov/eid/article/4/1/98-0108_article.htm
2. Statistics for bTB in the UK: http://www.defra.gov.uk/animal-diseases/a-z/bovine-tb/
3. M. bovis in cats: http://171.67.117.160/content/174/13/326.2.full
4. Liverpool liver fluke research and bTB: http://www.nature.com/news/bovine-tb-disguised-by-liver-fluke-1.10685