Saturday, 15 February 2014

Interview: 'Epistemic'- a film based on the life of Nikola Tesla

‘Epistemic’ is a short film currently in production, which is influenced by the life of the physicist and inventor, Nikola Tesla. To quickly sum up just how brilliant Nikola Tesla was (and why a film based on his life is such a great idea) it is important to remind ourselves of the many things we have to thank him for. These include: alternating current, radio, radar, x-rays, remote controls, lasers and many others!  The film  is set in the present day and focuses on a scientist’s attempts to turn the hypothetical possibility of perpetual motion into a reality, whilst being thwarted by her arrogant colleague, a character based on Thomas Edison. I interviewed the writers, Lewis Hancock and Sean Stoakes, and the Director of Photography, Jake French, to find out more about the project and to see how science has influenced art.

What inspired you to adapt the life of Nikola Tesla?

LH:  Sean originally came to me with the idea of doing a story based on the life of Tesla.

SS: Jake and I, both liked Nikola Tesla, and we thought his life would be an interesting foundation for a film. Originally we wanted to focus on his love for a pigeon and we kind of just wanted to do a more quirky romance film about a man who loves a pigeon. Then we came to realise that his personality and work had much more depth than this particular aspect we were focusing on. The concept of sensory overload, which he was noted to suffer from, really intrigued us from a visual and general filmmaking standpoint.

JF:  I think Tesla’s character is one deserving of more attention and exposure than actually given. He has often been overshadowed by the fame and success of Edison, so we feel that his genius deserves any publicity we may provide through this film.

Where does the title come from?

SS: Well the definition of the word is that it is relating to knowledge or its validation.

LH: So the film is based on the epistemic impossibility of the perpetual motion machine. Due to our current knowledge, it is impossible.

Was there any specific reasoning behind casting a woman in the Tesla role?

SS: There were several reasons...

LH. Yeah, there were really. It dawned on us that what we were playing with in terms of the themes of the film and the character, worked better with a woman in the role. Also, there just seems to be too many male leads in films and in combination with it fitting what we wanted to say and how we wanted to say it, it just worked better with a woman in that role.

SS: Film shares the same problems as the scientific world, in that it can be a bit of a lad’s game. It just seemed much more interesting and it had a great response with actresses coming to audition, who wanted to explore this interesting character. The point of the character is that it is the essence of Tesla. It could be played by a man or a woman. And I think this is important as we are representing a scientist. The sex of the character really isn’t important.

JF: Tesla was an asexual celibate his entire life, so male or female isn’t a defining characteristic.

What intrigued you about the rivalry between Tesla and Edison?

LH: He is the natural antagonist to Tesla’s story because of the real life events that happened, including Edison kind of betraying him and cheating him out of money.

SS: The element of scientific rivalry was interesting as well. The ruthless business side of science is not always what you imagine, but I guess it is like any other work. It really became quite integral to the film.

JF: A lot of info surrounding Tesla and Edison tends to focus on them being rivals in many aspects; however, it was often purely work related. Tesla actually had a lot of respect for Edison in terms of his work, but the history books were written to highlight the, let’s say, “screwing over” of Tesla done by Edison, which was committed seemingly out of spite.

Does the film show examples of their research?

SS: Not really...

(laughter)

LH: We provide symbolic hints to their work like light bulbs and electricity in the visual imagery. Obviously you cannot mention Tesla without thinking about lightning rods and the Tesla coil, which will be referenced.

SS: It has a modern setting and is a re-telling of their lives. Obviously we can’t recreate the invention of AC current in a world where it already exists. So the main focus is perpetual motion, which does not exist, but was something that Tesla worked on.

JF:  Our intention is not having the central theme of the film being science and equations, but on Tesla as a character. Anything scientific related will be portrayed through visuals and lighting, with consistent recurring themes, such as electricity.

As the film is set in modern times, which elements of Tesla’s biography were you able to portray in this new setting and what had to be removed?

LH: With Tesla, we focus more on the character’s mental condition and it was more towards the end of his life where it all started to take its toll. So the sensory overload he was suffering, his fixations, we could bring all that out in the modern character.

SS: We also had to cut out Tesla’s background. Not only is he now a woman, he is also no longer a Croat working in America. His brother died but here there is no reference to the character’s childhood.

LH: Really we have created a character that, rather than sharing his history, shares the same aptitudes and mental condition.

Are there any difficulties representing science through an artistic medium?

LH: Yeah...

SS: Because we are not scientists by any stretch of the imagination.

LH: We are being supported by scientists as we develop the film and we have a credited scientific advisor. But it’s strange choosing how you portray something, as not everyone in the audience will have a scientific background and won’t know what each specific machine does.

SS: As an artist creating something in this visual format we have ended up putting a lot of weird shit in it (laughter). While we are careful with portraying the scientific elements, it is a film and it is fantastical in places.

JF: We’re using our creative freedom as much as possible. As we are steering away from accurate scientific representations, we’re free to represent them any way we like, giving us great advantages in the uses of set design, lighting experimentation and (hopefully) most notably in the cinematography.

LH: In terms of portraying science, as long as we can get the atmosphere and the look right, the audience should believe in the film and most especially, the characters. And the film really does focus on the characters as scientists, rather than the science itself.

SS: Hopefully the scientists in the audience will appreciate that this is a story told in an entertaining and lively fashion and if you’re like us and know almost nothing, you can assume that we are geniuses!

Thank you gentlemen and I wish you the best of luck with the production.


The film will be released in May. You can get more information about the film on Twitter and Facebook: follow @Epistemic_Film  and https://www.facebook.com/epistemicshortfilm




Saturday, 11 January 2014

The Emerging Reality of a Fantastic Voyage

Back in my school days, one of the lessons that still remains clear in my memory was on the subject of nanotechnology (the use of material at an atomic and molecular scale). This is mainly due to my teacher’s prophetic warnings on tiny self replicating structures covering the world in eternally multiplying grey goo. Think B-movie style fear and screaming and this would pretty much sum up the level of scaremongering pitched in class.  Luckily scientists have not shared this view and the potential uses of nanotechnology are almost as numerous as the sum frequency of the dreaded grey goo.

While most work on the subject is still being held in the laboratory, nanotechnology is already being applied today. Mesoporous material (material containing pores with diameters 2 and 50 nanometres in length) have been used in a composite application with Self-Assembled Monolayers (where molecules assemble spontaneously on the material surface). They are able to capture target metals such as copper, lead and mercury from water. The ability to remove metal ions from waste water without the need for chemicals is a clear bonus when dealing with heavy metal pollution. It may also be possible to target radioactive material in the future.

The most interesting potential uses are in the field of medicine. Future bone reconstruction may be aided by nano-structured calcium phosphates. This synthetic bone substitute is made by breaking down the natural composition of bone into molecular components with small structural adjustments. Experiments on the use of nanoparticles for cancer treatment are increasing and last month, research was published where the mitochondria of cancer cells (the power houses of the cell) were targeted by drug delivered nanoparticles.  Nanodiamonds can also be used to retain chemotherapy drugs in cancer cells for patients suffering from leukaemia, increasing the chance of treatment success.


Every year the list of potential uses increases and this small review of some of the more interesting research does not even scratch off a few skin cells of the surface. Researching this subject makes apparent how small the barrier between science fact and science fiction has become. If you compare the two images in this post, the first is an illustrative example of potential medical treatments related to nanotechnology, while the second is an illustrative cover from the paperback tie in to the 1966 film, Fantastic Voyage. Other than a lack of nano-sized humans causing trouble in a nano sized submarine travelling though the body, the differences in style are minimal. This is a clear example that while there is much to do to make some of the uses of nanotechnology a reality, we really are not that far off.

References:
Chow, E.K. et al. (2011). ‘Nanodiamond therapeutic delivery agents mediate enhanced chemo resistant tumor treatment’, Science Translational Medicine, 3 (73), pp. 21-22.
Doss, C.G.P. et al. (2013). ‘Disruption of mitochondrial complexes in cancer stem cells through nano-based drug delivery: a promising mitochondrial medicine’, Cell Biochemistry and Biophysics, 67 (3), pp. 1075-1079.
Fryxell, G.E. et al. (2002). ‘Environmental applications of self-assembled monolayers on mesoporous supports (SAMMS)’, Studies in Surface Style and Catalysis, 141 (1), pp. 583-590.

Credits:

Saturday, 14 December 2013

A Review of 'A Passion for Science', Edited by Suw Charman-Anderson

 ‘A Passion for Science’ is filled with fervour and shared excitement at the wonders of the world (and beyond). The book contains short biographies of women who have been at the forefront of incredible scientific breakthroughs and innovations, written by those who were inspired to go on their own scientific journeys because of their remarkable lives. While the scope of the book covers scientists in such diverse areas as, astronomy, embryology, geology and palaeontology (to name but a few), the women are united in the dedication and zeal they brought to their work. From the very first chapter, it is impossible to resist following these women in their quests for knowledge and sharing in the joy of discovery. If you have ever felt even the smallest longing to comprehend a part of the universe we live in, which had otherwise been previously unknown, then this book will stir up all those long forgotten yearnings.

What really makes this work stand out is the emphasis on the sexist attitudes that historically closed doors to women in the scientific profession. It took a mixture of motivation and bravery to remove the barriers between themselves and success, which has allowed countless women to forge accomplished careers in science and technology since. One of the most beautiful anecdotes explains the sadness a young Joan Feynman felt having been told that ‘women can’t do science’ and the hope and encouragement which came from reading the name of a female scientist in an Astronomy book. That woman was Cecilia Payne-Gaposchkin, a successful astronomer whose life is described in the book and her name inspired Joan Feynman to begin a triumphant career in science. As each page is filled with such stories, you cannot fail to be motivated in your own dreams (whether science related or not).

Sadly there are still barriers to women learning and launching careers in science and technology due to entrenched sexism in education and industry. The writers and editor of ‘A Passion for Science’ understand this deeply, and the book was created as part of the Ada Lovelace Day initiative. Ada Lovelace Day celebrates the achievements of women in science, technology, engineering and maths while also providing role models to inspire the scientists of tomorrow. As someone who hopes to forge a career in a science related field, I cannot express enough the importance of female role models to show that my hopes and imaginings are not just pipe dreams, but achievable goals. It is important to note that the women in this book are not just role models for future scientists. The grit and determination necessary to make such brilliant contributions to their field can be admired by anyone. Whatever your passion and ambition, this book has the ability to inspire.


If you are interested in purchasing the ebook, then head over to http://findingada.com/book/  where you can get an exclusive 25% discount by using the code ‘quarks’ at the checkout. If you wish to learn more about Ada Lovelace Day (which I implore you to do) check out the website: http://findingada.com/ or follow: @FindingAda.

Sunday, 8 December 2013

Belated Birthday Blog- The Biology of Ageing

As another birthday has passed I thought this week’s entry should be on an associated theme- the biology of ageing. This is another huge topic that I will be indulging in only the most superficial of levels. But the process of ageing in cells is fascinating in terms of both the mechanism and possible future research.

Telomeres are regions of DNA with repeat, non coding information which protect the ends of the chromosome from deterioration during replication. As chromosome ends shorten with each replication, eventually the DNA that keeps everything ticking over nicely will be lost. Instead, telomeres are shortened during each cell division and while they exist, new cells can maintain their structural and functional integrity. In regular cells the shortening of telomeres leads to apoptosis (programmed cell death) but in abnormal cells, continued cell division once the telomere is depleted may lead to chromosome instability with associated consequences-from ageing to cancer.

The mechanism for ageing even at a cellular level is not fully understood (no matter what the latest wonder cream advertisement suggests). One of the ways in which scientists study this mechanism is by analysing disorders that cause premature ageing, such as Hutchinson-Gilford Progeria Syndrome (HGPS). The disease is caused by mutations in the gene LMNA and its symptoms represent areas of ageing manifesting so rapidly, that suffers live to a mean age of only 12.6 years. Studies have shown that the average length of telomeres in HGPS patients is much shorter than people of the same age. However, the method by which the mutation in the LMNA gene causes telomere shortening is not fully understood.

An example of cluster telomeres (purple areas) in 'boquet' proteins in yeast during meiosis. 
A recent study compared telomere length with physical performance in advanced age. Telomere size data was collected from adults aged between 53-80 years of age and their performance in tasks (ranging from walking to chair rise speed) was measured. Perhaps unsurprisingly, there was no correlation between age deteriorating-physical performance and telomere length. Therefore, the importance of telomeres in the process of ageing remains at a cellular level only.

On a more positive note, scientists are looking at the potential use of rejuvenating senescent cells (cells that can no longer divide and replicate) as a method for postponing the ageing process. While still only a scientific pipe dream, it may be possible to reprogram cells by induced pluripotent stem cells (iPSCs) or by modifying the senescent cell signalling pathways with pharmacological or natural agents. It should be noted that senescent cells do have important roles in keeping the body functioning properly, including regulating the wound healing mechanism and mobilizing the immune system to clear cancer cells. Therefore, any attempts at the rejuvenation of senescent cells would have to weigh the risks to these important processes against the benefits of halted ageing.

The biological ageing process is so complex that the scientific community is only piercing the surface of potential understanding in order to replicate the mechanisms involved. While it may never be possible to eliminate ageing (nor perhaps should we aim for it), the goal of prolonging a healthy life span is worthy at a time when an ageing population is seen as an increasing economical and social worry. How far research can take us towards that goal remains to be seen.

Further reading:
Basu, N. et al. (2013). ‘Telomeres and Telomere Dynamics: Relevance to Cancers of the GI Tract’, Expert Review of Gastroenterology and Hepatology, 7 (8), pp. 733-748.
Decker, M.L., Chavez, E., Vulto, I. and Lansdorp, P.M. (2009). ‘Telomere Length in Hutchinson-Gilford Progeria Syndrome’, Mechanisms of Aging and Development, 130 (6), pp. 377-383.
Gardner, M.P. et al. (2013). ‘Telomere Length and Physical Performance at Older Ages: An Individual Participant Meta-Analysis’, PloS One, 8 (7), e.69526.
Sikora, E. (2013). ‘Rejuvination of Senescent Cells- The Road to Postponing Human Aging and Age-Related Disease?’ Experimental Gerontology, 48 (7), pp. 661-666.

Saturday, 30 November 2013

Palaeopathology Series, Part 1: Venereal Syphilis

This is the start of an occasional series on Palaeopathology (the study of ancient diseases) which I enjoyed studying as an undergraduate. I expect a large amount of sympathy for the many grotesque images I have had to endure in the quest for knowledge, especially considering the nature of Part One- an Introduction to Venereal Syphilis.

Venereal Syphilis is an infectious disease that is a member of a group of disorders called Treponemetoses, caused by the bacterium, Treponema pallidum subspecies pallidum. The infection occurs in three stages: the primary stage where a painless lesion occurs at the entry site of infection, the secondary stage as a skin rash develops (along with mucous membrane lesions) and finally the tertiary stage, marked by the infection spreading to the organs in the Central Nervous System, as well as the heart and skeleton. In 20-30% of cases tertiary symptoms can manifest 5-20 years after the original infection. Without our good friend the humble antibiotic, the numbers of cases reaching this stage in history were immense. Luckily for Palaeopathologists, the fact that symptoms can be found on the skeleton allows for the analysis of historical diseases including disease history, geographical spread and the ability to predict similar infection courses in the future.

The most frequent symptoms of Venereal Syphilis found on the skeleton are bi-lateral lesions most commonly occurring on the tibia and skull (frontal, parietal and nasal-palatial regions). If the infection advances to the Central Nervous System then Neurosyphilis can occur. This infection of the brain and spinal cord can cause many debilitating effects when living, such as headaches, numbness in the extremities and seizures. In historical cases, indirect evidence of this type of disorder can be found as a Charcot’s joint, which is caused by repeated trauma occurring at the joints, due to a lack of pain perception.

Analysis of the skeletal symptoms of Venereal Syphilis has been used in attempts to deduce the mysterious emergence of the disease. The earliest known reports of Venereal Syphilis came from Naples in 1495, when a ‘plague’ broke out among the French King, Charles VIII’s troops. It is thought that when they later disbanded the disease was spread throughout Europe. How and when Venereal Syphilis arrived in Europe is a matter of great controversy with two opposing schools of thought contesting a different historical background. The first believes that there is an association with the timing of Christopher Columbus’ return voyage to Europe from North America, with the bacteria transported aboard ships. The other believes there is evidence for Venereal Syphilis being present in the Old World before the voyage in 1493. The difficulty in evaluating the history of the disease is that the remaining evidence of Syphilis found on the skeleton can often be mistaken for other disorders (such as Tuberculosis) and there has been recent controversy over non-peer reviewed research on supposed syphilitic skeletal remains found in pre-1493 Europe, being represented in the media.

Recently, the Columbian hypothesis has been refined with the belief that the Columbus voyage transported a Treponemal bacterium that was nonvenereal, and which later adapted under new selective pressures in the Old World to become Venereal Syphilis. While this theory is intriguing, a problem arises due to the short time in which the bacterium would have had to adapt and become sexually transmitted in this new environment (especially if the first known case was in Naples, 1495). Phylogenetic studies on treponemal disease may be the next step in illuminating the history of this interesting disease, going beyond the limitation of osteological observation.

This is just a brief overview of a few of the skeletal symptoms and the controversial emergence of one of the most virulent diseases in history. I encourage you to research further and increase your disgust, but be warned- what has been seen on google images can never be unseen!

Further Reading:
Armelagos, G.J., Zuckerman, M.H. and Harper, K.N. (2012) The science behind pre-Columbian evidence of syphilis in Europe: research by documentary. Evolutionary Anthropology, 21(2), pp.50-57.
Salazar, J.C., Hazlett, K.R. and Radolf, J.D. (2002) The immune response to infection with Treponema pallidum, the stealth pathogen. Microbes and Infection, 4(11), pp. 1133-1140.
Sequeira, W. (1994) The neuropathic joint. Clinical and Experimental Rheumatology, 12(3), pp. 325-337.
Credits: <a href="http://www.flickr.com/photos/26312642@N00/2524462429/">an untrained eye</a> via <a href="http://compfight.com">Compfight</a> <a href="http://creativecommons.org/licenses/by-nc/2.0/">cc</a>

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Saturday, 23 November 2013

The Weird (and often Traumatic) World of Animal Sex

Anyone who has ever had to witness the horrific site of mallard duck (Anas platyrhynchos) mating when taking a young child for an innocent ‘feeding the ducks’ experience, will know the discomfort it can produce. For those who do not, the defining reason for this discomfort is the fact that mallard ducks often violently rape females during mating. A little known fact is that females have developed their own anatomical quirks, in what can be described as an evolutionary sexual arms race. As the males have phalluses big enough not to require consent from females when mating, female vaginas have spiral channels which twist in the opposite direction to that of the male genitalia. In some cases, ducks have evolved cul-de-sac pouches which prevent sperm from fertilising an egg, which allows the female to have some control of the second half of the genetic material that will be passed on to her offspring.

Recent research has discovered another traumatic mating ritual in the animal kingdom. A species of sea slug (Siphopteron species 1) has been found to stab each partner centrally in the forehead with an organ called a penile stylet, during copulation. As the slugs are hermaphrodites (having both sets of reproductive organs) there is a reproductive advantage to acting as the male when mating, due to the potential to create more offspring by being free to fertilise other slugs after copulation. By stabbing each other in the head and injecting a secretion which has the ability to control the other slug’s behaviour and prevent it from mating again, this may provide more time for the sperm to fertilise the eggs and force the slug into the female role.

Another interesting mating technique is found in a certain species of snake. Red-sided garter snakes (Thamnophis sirtalis parietalis) mate in a mass orgy of slithering reptiles. This is less traumatic for the animal but still pretty vile for the snake fearing masses out there. The female produces a pheromone to attract male snakes in great numbers, which creates a mating ball of competing males surrounding the female. The pheromone can provide the following information to the male: correct species, population, sex, season, reproductive condition and age. The successful male who gets to mate with the female deposits a gelatinous copulatory plug that can reduce the chances of the female re-mating and works as a spermatophere (a protein matrix from which sperm are released as the plug dissolves). This mechanism increases the chances of successful fertilisation when competition is fierce and time is short.

Other research emphasises the profound weirdness of mating in this species of snake. So called, ‘she-males,’ can also produce small amounts of this female sex hormone to trick male red-sided garter snakes into courting them. As snakes are cold blooded, a slower, weaker snake would have an advantage i
n creating warmth (needed in the cooler spring months of the mating season) by attracting a mating ball to itself.

These examples of the weird and wonderful ways in which animals create the next generation, only just scratch the surface of the intriguing research being carried out on the topic. It is a subject that both fascinates and disgusts in equal measure and will continue to cause adults many awkward trips to the park with their own offspring.

Further reading:
Brennan, P.L.R. et al. (2007). ‘Coevolution of male and female genital morphology in waterfowl,’ PLOS One, 2(5), pp. e418.
Frieson, C.R., Shine, R., Krohmer, R.W. and Mason, R.T. (2013). ‘Not just a chastity belt: the functional significance of mating plugs in garter snakes, revisited’, Biological Journal of the Linnean Society, 109(4), pp. 893-907.
Lange, R., Werminghausen, J. and Anthes, N. (2014). ‘Cephalo-traumatic secretion transfer in a hermaphrodite sea slug’, Proceedings of the Royal Society B, 281(1), pp. 1-6. (Published online: 13 November 2013).
Parker, M.R. and Mason, R.T. (2012). ‘How to make a sexy snake: estrogen activation of female sex pheromone in female red-sided garter snakes’, The Journal of Experimental Biology, 215(5), pp. 723-730.
Credits: <a href="http://www.flickr.com/photos/21390400@N04/2979468289/">anchoredbyflight</a> via <a href="http://compfight.com">Compfight</a> <a href="http://creativecommons.org/licenses/by-nc-nd/2.0/">cc</a>
 http://www.youtube.com/watch?v=yyhvBGeKgqk

Saturday, 16 November 2013

Our Parents are Aliens?

Panspermia is the idea that life on a planet can be established by distribution from one celestial body to another, via natural means. The original concept was proposed in 1865 by Hermann Eberhard Friedrich Richter and over the years it has gained remarkable popularity (if not solid evidence). Scientists are researching the potential for microbes to survive the harsh environments of space, atmospheric entry and the impact on Earth necessary for the hypothesis to be true. This may all sound suspiciously like Ridley Scott’s ‘Prometheus’ but I can assure you that the science is far more interesting than any mediocre film could convey.

 Past research has suggested that DNA is highly vulnerable to destruction by cosmic radiation, but another molecule call
ed RNA may have had the potential to kick-start life on Earth. This is because RNA has the ability to reproduce without help (eg. enzymes). It can, on its own, create secondary and tertiary structures which could catalyse the production of other RNA molecules. If life on Earth started off with an ‘RNA world’ and there was an eventual transition to DNA, then RNA-viruses may have taken a role- if the Panspermia theory is to be believed. However, the huge difficulty in this concept is that viruses need a host to survive (a factor sadly lacking when forming new life on a planet) and unless evidence suggests ancient viruses could live without this basic requirement, the hypothesis falls flat.

While the Panspermia theory seemed dead in the (lifeless) waters, later evidence has suggested that ancient life-forms may have been capable of surviving the harsh atmospheric conditions of space. In 2011, it was found that certain types of microbes (brilliantly named extremophiles for their hardy resistance to the most extreme conditions- including nuclear reactors) could survive in frozen environments such as underground lakes in Antarctica. The adaptations necessary to live in such a severe environment would be essential if they were to be successfully carried through space on ice-cold comets. Furthermore, experimental data has proven that organic molecules could survive prolonged atmospheric re-entry. 

This week’s latest research suggests organic material can survive the capture, transport and impact of a high force contact event. The Darwin crater in Western Tanzania (a crater left from an impact with the earth 800,000 years ago) created impact glass due to the high temperature and pressure associated with the collision. Analysis of the glass has found surprising evidence for the organic remnants of the ancient ecosystem which was hit by the meteor. This is the first study of its kind to present evidence of life surviving either on the terrestrial surface or inside a meteorite that has impacted Earth.  While this research does bring some weight to the Panspermia hypothesis, the Darwin crater is relatively small and it has yet to be proven that life could survive a much bigger impact.

Though still only a theory, the Panspermia hypothesis does have some weighty scientific evidence to pin down the more sci-fi elements. Life on earth may not have extraterrestrial origins, but the potential for microbes to survive in the most inhospitable environments may provide interesting developments in the future.

Further reading:
Howard, K.T. et al. (2013). Biomass Preservation in Impact Melt Ejecta [Online]. Natural Geoscience (Advanced Online Publication). Available at: http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1996.html (Accessed 14 Nov 2013).
Parrilli, E., Sannino, F., Marino, G. and Tutino, M.L. (2011). ‘Life in Ice Habitats: New Insights Supporting Panspermia Theory’, Rendiconti Lincei, 22 (4), pp. 375-383.
Parnell, J. et al. (2011). ‘Preservation of Organic Matter in the STONE 6 Artificial Meteorite Experiment’, Icarus, 212 (1), pp. 390-402.
Wesson, P.S. (2010) ‘Panspermia, Past and Present: Astrophysical and Biophysical Conditions for the Dissemination of Life in Space’, Space Science Review, 156 (1), pp. 239-252.

Credits: <a href="http://www.flickr.com/photos/39057386@N02/4111291263/">Navicore</a> via <a href="http://compfight.com">Compfight</a> <a href="http://creativecommons.org/licenses/by/2.0/">cc</a>
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