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Ancient infections: the parasites that shaped our health
[Reporting from the British Science Festival, Sept 12th 2013]
Early humans started to migrate from Africa 100,000 years ago, taking with them early human tools, early human culture – and early human health problems. What happened to the parasites that plagued us in our ancestral homeland? Which did we leave behind and which only began to play a role in human health after our spread to other continents?
Combined interests in parasitology and anthropology led Dr Piers Mitchell of the University of Cambridge to the same questions. Speaking at the British Science Festival today, he unveiled new research that tracks the historical range of human parasites to paint a picture of what parasites affected us when and where, providing an image of how diseases spread throughout human evolution.
Mitchell’s study is the first to take a global approach to historical human parasitology, and as such, uses evidence from an exotic range of sources: fossilised human faeces, archaeological sites, and mummified human remains from Egypt, including the mysterious contents of canopic jars. In these samples were evidence of ancient diseases, in the form of equally ancient parasitic remains. This information was then integrated with parasitology data from modern non-human primates such as gorillas and chimpanzees to complete the picture of how these parasites spread across time.
This research has allowed Mitchell to pinpoint 16 parasites he calls “heirloom” parasites, those which humans were ancestrally exposed to in Africa, possibly during our evolution. Of these, six did not spread outside Africa. A further 12 parasites are “souvenir” parasites which early humans acquired, probably from wild animals, as they migrated north, west and east. These were picked up in the same way that we might pick up a souvenir on our travels, says Mitchell.
Crucially, this is the first time that research has determined which parasites humans may have co-evolved with, a finding that could have implications for modern medicine. The assumption is that if we evolved under exposure to heirloom parasites such as threadworms and liver flukes, we should be physiologically more capable of dealing with these than those which we came into contact with much later. An increasingly well-studied link between high incidence of parasite infection and low rates of allergic diseases in developing countries has led scientists to suggest that parasites could be used in the treatment of extreme allergies. Heirloom parasites that we should be better evolved to cope with would be ideal target species for such research.
A link between historical human association with a parasite and our physiological capability to deal with it clearly requires further testing – the list of heirloom parasites includes malaria and leishmaniasis, both of which can be fatal regardless of how many thousands of years humans have had to evolve resistance to them. If more innocuous heirloom parasites, however, could be used to treat allergic diseases, the impact of Dr Mitchell’s work on the history of human parasites could stretch well into the future.
The power of poo
[Reporting from the British Science Festival, Sept 12th 2013]
Few of us think twice about what we flush down our toilets. For some, however, it’s a source of infinitely renewable energy that could power our future sewage plants, and more. Speaking at the British Science Festival today, experts from Northumbrian Water and Newcastle University spoke of their shared commitment to harnessing the energy inherent in our waste – literally, the power of poo.
“It takes a lot of energy to treat a metre cubed of waste water,” explains Professor Tom Curtis, Professor of Biological Engineering at Newcastle University. “But that waste water contains even more energy than it takes to treat it!”
Curtis and colleagues are currently working with Northumbrian Water to find the best and most efficient way of extracting that energy to make the water treatment process a sustainable, even profitable venture. Currently, they are trialling a hydrogen Microbial Electrolysis Cell (MEC), a fuel cell that produces hydrogen gas from raw sewage. This hydrogen gas is a valuable fuel, worth about six times as much as methane, the main gas produced by older methods of sewage treatment.
“Northumbrian Water is industry leading in terms of this kind of sustainable power,” says Commercial Director Dr Maxine Mayhew. With 2.6 million customers, and 400 water treatment plants, the process of treating waste water results in a massive 1.6 million tons of sludge per year. Fifteen years ago, that would have been dumped at sea. With the sense that they were, literally, wasting their waste, Northumbrian Water began to use treatment methods that produced gas from their sludge, that in turn could produce power. By doing this, they became the first waste water company in the UK to make use of all the sludge produced by their plants to generate energy.
Now, their aim is to make this energy production even more efficient. The UK uses about 2% of its energy treating waste water, says Curtis, a percentage of our energy bill that could be eliminated by using Microbial Electrolysis Cells. Mayhew believes that by 2015, a fifth of all power used at Northumbrian Water will be from biological sources – and further in the future, they could power themselves completely.
From an academic point of view, Curtis is blunt about the rate at which such renewable energy-producing systems are being developed, relative to the need for sustainable energy.
“If we go at the rate of one PhD at a time, it will take twenty or thirty years to see this kind of energy production implemented in the UK,” he says. “We just don’t have twenty or thirty years!”
The need to increase the rate of innovation, he says, necessitates a trial-and-error approach that diverges slightly from his academic background. “Academics strive for perfection,” he says with a smile. “We’re trying to get away from that.”
Take off your shoes - and run!
[Reporting from the British Science Festival, Sept 11th 2013]
The idea is simple. Our ancestors ran without shoes, relying on their ability to do so to feed and clothe themselves. So why do we need the latest cushion-soled, ankle-supporting, pound-sucking creations from the top sports-shoe brands to do what they did with none?
Barefoot running first came into the spotlight when, in 1960, Ethiopian runner Abebe Bikila ran unshod through the cobbled streets of Rome, on his way to an Olympic gold medal and a new world record. In recent years it has become increasingly popular with those who say it is a better, more natural way to run, and that running without shoes prevents injuries and increases performance.
Little of this is based on research, however, says Dr Mick Wilkinson, who works on the physiology of distance running at Northumbria University’s Department for Sport and Exercise. To date, no studies have actually tested differences in injury rates or performance improvement between runners with and without shoes.
What has been shown, though, is that habitual barefoot runners land on their fore- or mid-foot, which better absorbs the impact that is normally concentrated on the runner’s heel. But, says Wilkinson, these benefits will only be felt by runners if they are doing it right.
Most major sporting brands now sell some variation on a barefoot running shoe – essentially a glove for the foot that prevents the wear and tear you might expect from running on varied surfaces, but that doesn’t provide any support or cushioning. Wilkinson is keen to point out that when he talks about barefoot running, he doesn’t mean running with these. So, what’s the difference?
“Sixty to seventy percent of ‘barefoot’ shoe-wearers still run in the same style as they did when they were wearing trainers,” he says. In other words, they are still hitting the ground with their heel first, this time with no cushioning to absorb that blow – and in fact, are putting themselves at a much higher risk of injury. A sense of friction on the sole, he says, is the trigger for the body to reduce the impact by switching to a fore- or mid-foot gait. Even with a few millimetres to protect the heel, this sensation can be lost, and runners unused to a mid-foot gait can revert to landing hard on the heel; this is why he says he stops barefoot running in winter “when it’s too cold to feel my feet”.
Wilkinson was in fact one of the two first people to complete the entire Great North Run without shoes in 2011, and is an enthusiastic proponent of this running style, though he cautions that transitioning from one running style to another should be done very gradually to avoid injury. He has good news though, for parents of would-be runners, or amateurs starting for the first time. In terms of biomechanics, there is no difference between top of the range “barefoot” shoes, and simple plimsolls, and starting out in either will naturally encourage a fore- or mid-foot running gait. “Buy basic shoes,” is his advice, and it might even be enough to get me on the roads.
The economic and scientific ripples of landslides
[Reporting from the British Science Festival, Sept 11th 2013]
A five-fold increase in landslide events in the UK is due to heavy rainfall, say experts from the British Geological Survey and the Transport Research Laboratory.
Speaking today at the British Science Festival, Dr Helen Reeves and Dr Mike Winter linked the unusually high rainfall experienced across the country in 2012 - the wettest year since records began – to a leap in the incidence of landslides recorded by the British Geological Survey’s Landslide Response Team. One hundred and seventy-six landslides were recorded last year, causing a total of four fatalities – the first deaths related to landslides since 2006, when the Landslide Response Team began monitoring the press for information on local landslide events.
Dr Helen Reeves of the British Geological Survey says they are moving towards the “holy grail” – the ability to forecast landslide events at a regional and local level. The susceptibility of a slope to landslides is largely determined by rainfall, which increases the volume of water in the slope. When this reaches a level where the weight of the water is too much for the soil and rock to hold, gravity takes over, and the rocks and earth fall. A better understanding of the link between landslides and rainfall patterns will eventually allow the British Geological Survey to link weather forecasting with the likelihood of landslides occurring, with important implications for public safety.
Dr Mike Winter, Head of Ground Engineering at the Transport Research Laboratory, says that it is too soon to determine whether there is a link between the increase in landslide events and climate change. Patterns, however, seem to be emerging. In Scotland, for example, the average rainfall per year has remained more or less the same – but the patterns of how this rain is falling are different. There are now more storms during which rain falls with increased intensity over a shorter duration, more likely, says Winter, to trigger landslides.
An increase in landslide events inevitably also increases the risk of damage to transport and other infrastructure, with costly implications. Both Reeves and Winter say that it is difficult, however, to quantify or predict the economic impacts of landslide events. Damage associated with landslides in 2012 was substantial, and expensive. A debris-flow landslide on the busy A83 Rest and Be Thankful pass in Argyll caused road closures that cost the local economy £50,000 a day; a permanent engineering solution could cost upwards of £500million.
While the frequency of bad weather and landslides are increasing, so too is the use of an unlikely tool – Twitter. Reeves says that the British Geological Survey, now tweeting at @BGSLandslides, are increasingly able to take advantage of social media to find reports of landslides that might otherwise have gone unreported. The fast flow of information also means that they know about events faster than ever before. “Hopefully this information will help us break new ground,” says Winter. “Excuse the pun.”
Review: “No”
In 1988 Pablo Larrain and Pedro Peirano - Chilean director and writer of No, the winner of the prestigious Director’s Fortnight prize at Cannes last year - were twelve and sixteen years old. Under international pressure to legitimise the Presidency of General Augusto Pinochet, the Chilean government staged a referendum: yes, or no, to another eight years under his globally condemned military regime. The government and the opposition were given 15 minutes on air every day for 27 days to convince the Chilean people to vote yes or no.
The result was arguably the most important ad campaign in Latin American history, documented in this clever, witty and evocative film. Rene Saavedra (Gael Garcia Bernal) is an exile returned to Santiago, where connections have propelled him above the brittle violence of 1980s Chile. As an advertising agent head-hunted by the “No” campaign, he is pulled deep into a murkier world of political wrangling, censorship, and the ever-present threat of detention and disappearance at the hands of the regime. The film is entirely shot on the old-fashioned three-strip video used in the ‘80s, lending an authenticity and tangibility to the growing feeling of threat, which becomes slowly evident through over-exposed light and shaky zooms. Couched in the music and humour of a deliberately upbeat ad campaign, the violence is chilling.
It has been nine years since his much-lauded turn as the iconic Ernesto Guevara, and Gael Garcia Bernal has aged, though not enough to lose the wide-eyed sincerity that gave credence to his political fervour in The Motorcycle Diaries. In No, however, he plays a different sort of hero. Bernal gives an assured performance that is the axis of the film. Here, he is an older, more cynical, less gauche revolutionary, but still conveys a credible earnestness while deftly handling the lighter moments of the film.
The film begins and ends with Saavedra giving almost identical sales pitches, a reminder that this is a film about the world of advertising as much as it is a film about Chile. There is welcome levity in the struggle to fashion democracy into a sellable product, and there were frequent laughs throughout the cinema. The slick world of advertising, however, is uneasily married to the grim reality of disappearances, tortures and executions under Pinochet. This maintains a taut atmosphere, but also serves as a wry reminder of the power of the media and its ability to distort the truth.
Despite the success of the “No” campaign in ousting Pinochet in 1988, the film ends not with triumph, but with a sense of things continuing without much change. Maria Eugenia Bravo, former Chilean prisoner and exile, believes that indeed, today’s Chile is little improved. Speaking at a Q&A session at the Cambridge Arts Picturehouse, she points out that the constitution is still as it was under the General, and says that Chile is a country “still divided.” A professor at the University of Chile until her detention, subsequent torture, and escape to the UK, Bravo supports Amnesty International’s campaign to change laws that grant impunity to perpetrators of human rights abuses under the Pinochet regime. Although she sees the film as “a real success for the Chilean people”, she points out that “many are still waiting for justice”. Up for a Best Foreign Film gong at this year’s Academy Awards, No could well inaugurate the exploration of Chile’s difficult past.
Published in The Cambridge Student, 12th March 2013