Geolog, the blog of the European Geosciences Union
Geosciences Column: Did Mediterranean salt change the global climate? Published online June 2014.
Geosciences Column: Did Mediterranean salt change the global climate? Published online June 2014.
European Grid Infrastructure and International Science Grid This Week
Grid computing aids battle to reduce groundwater toxicity ISGTW. Published online July 2014.
Tracking a biomarker for Alzheimer’s disease EGI.eu. Published online January 2014
Virtual Space EGI.eu. Published online February 2014
Grid computing aids battle to reduce groundwater toxicity ISGTW. Published online July 2014.
Tracking a biomarker for Alzheimer’s disease EGI.eu. Published online January 2014
Virtual Space EGI.eu. Published online February 2014
The Royal Society
2012 Summer Science Exhibition
Ageing: a natural part of life or a treatable biological condition? Published online July 2012
2011 One Culture Festival 2011
Begotten, not created: how narratives emerge in science and literature Published online October 2011
What makes science-fiction? China Mieville in conversation with Tom Hunter Published online October 2011
A Storyteller Who Studied Maths: Apostolos Doxiadis in conversation with Marcus du Sautoy Published online October 2011
2012 Summer Science Exhibition
Ageing: a natural part of life or a treatable biological condition? Published online July 2012
2011 One Culture Festival 2011
Begotten, not created: how narratives emerge in science and literature Published online October 2011
What makes science-fiction? China Mieville in conversation with Tom Hunter Published online October 2011
A Storyteller Who Studied Maths: Apostolos Doxiadis in conversation with Marcus du Sautoy Published online October 2011
2011 Summer Science Exhibition
[Originally available at http://blogs.royalsociety.org/sciencelive/2011/07/13/seeingtheinvisible/]
Seeing the Invisible
Eeyore’s mournful expression peeks out through a loose cradle of optic fibres. The little donkey sits in the middle of the translucent bundle, acting his incredible part in the 2011 Royal Society Summer Science Exhibition. For in this exhibit, he is no mere toy donkey. He is the fantastic, light bending, Invisible Eeyore.
Ulf Leonhardt, Professor of Theoretical Physics at St. Andrews University, explains that the Eeyore display is mimicking the powers of the Invisible Woman, who can bend light around herself so that she vanishes from sight. Her forcefield sends the light straight back at the viewer, without any being absorbed and reflected as colour.
“Why Eeyore?” I ask.
He smiles and shrugs. “Well, we just needed any toy.”
But I think it is a very appropriate choice. Gloomy Eeyore probably would want to hide from the world, if he could.
The Professor shines a light through one end of the optic fibre bundle, showing how the light travels straight through the fibres and curves around Eeyore to
appear at the other end. He blocks some of the light using a plastic sheet printed with numbers, and the black numbers show visibly at the other end.
The display only represents the bending of light from one direction, but nonetheless, it is fascinating. “If you could do this from all directions, you could make him disappear,” says Professor Leonhardt.
He is part of a group of scientists hosting a lightbending exhibit entitled ‘Geometry and Light: The Science of Invisibility’. The stall is a perfect combination of superheroes, science-fiction, mysterious displays, and friendly scientists.
Moving to another part of the exhibit, Professor Leonhardt shows me how objects can be made to vanish inside a clear medium, like a liquid. He holds a cube of clear jellyish material above the surface of a tank of water, then lets it drop. The cube seems to vanish as soon as it touches the water, and he invites me to swirl through another seemingly empty tank with a fishing net. I dunk it in and scoop up a huge pile of clear, squishy marbles. It’s immensely satisfying, like
ponddipping for magic frogspawn, and I want to reach in with my hand for an invisible handful of the squeezy shapes. Luckily for me, this sort of messy visitor interaction is perfectly acceptable, and people can even take home their own free vial of invisible sphere and water.
I ask if it is the shape of the object which causes them to vanish in water.
Ulf explains it's not the shape that matters, but the substance. The objects are made out of a material matches the water’s refractive index, which is the amount that light is bent when passing through an object. Light passing through the water also passes through the spheres and cubes without being scattered or reflected. If the objects were dropped into another liquid of a different refractive index, then I would be able to see them.
This is the science behind the Invisible Man a man who could change his own body cells to match the refractive index of air.
Further along the stall, I see a low table spattered with messy pieces of clear jelly shapes. They have an alluring and eerie blue glow in the stall’s lighting, and I have to investigate. Another scientist, Joanna, shows me how the shapes, which are made from simple kitchen jelly, refract and
bend a ray of light shot from a laser pointer. The ray is sent on a journey of zigzagging angles across the table.
I can’t help it. She’s wielding a glowing laser pointer like a wand, and the whole team are wearing academic gowns that look like splendid flapping black robes. They’re bending rays of coloured light and casually vanishing solid shapes in liquids. Forget today's premiere of Harry Potter. Right now these people are the closest things to true wizards in the whole of London! I have to ask about invisibility cloaks.
“I think we’re a long way from anything like a Harry Potterstyle Invisibility Cloak,” Joanna says with a sympathetic smile. She shows me how the jelly bends red light differently to green light, because of their different wavelengths. This is why white light passing through a glass prism spreads out into separate colours. A true invisibility cloak would need to refract all the different wavelengths of light in the same way.
Still, this stall shows the possibilities of bending light, and explains the science behind the fibre optic technology revolution of the past few decades. The more we learn about how to manipulate light, the more we can use it. We'll have to wait and see- or try to see- what the future holds.
[Originally available at http://blogs.royalsociety.org/sciencelive/2011/07/13/seeingtheinvisible/]
Seeing the Invisible
Eeyore’s mournful expression peeks out through a loose cradle of optic fibres. The little donkey sits in the middle of the translucent bundle, acting his incredible part in the 2011 Royal Society Summer Science Exhibition. For in this exhibit, he is no mere toy donkey. He is the fantastic, light bending, Invisible Eeyore.
Ulf Leonhardt, Professor of Theoretical Physics at St. Andrews University, explains that the Eeyore display is mimicking the powers of the Invisible Woman, who can bend light around herself so that she vanishes from sight. Her forcefield sends the light straight back at the viewer, without any being absorbed and reflected as colour.
“Why Eeyore?” I ask.
He smiles and shrugs. “Well, we just needed any toy.”
But I think it is a very appropriate choice. Gloomy Eeyore probably would want to hide from the world, if he could.
The Professor shines a light through one end of the optic fibre bundle, showing how the light travels straight through the fibres and curves around Eeyore to
appear at the other end. He blocks some of the light using a plastic sheet printed with numbers, and the black numbers show visibly at the other end.
The display only represents the bending of light from one direction, but nonetheless, it is fascinating. “If you could do this from all directions, you could make him disappear,” says Professor Leonhardt.
He is part of a group of scientists hosting a lightbending exhibit entitled ‘Geometry and Light: The Science of Invisibility’. The stall is a perfect combination of superheroes, science-fiction, mysterious displays, and friendly scientists.
Moving to another part of the exhibit, Professor Leonhardt shows me how objects can be made to vanish inside a clear medium, like a liquid. He holds a cube of clear jellyish material above the surface of a tank of water, then lets it drop. The cube seems to vanish as soon as it touches the water, and he invites me to swirl through another seemingly empty tank with a fishing net. I dunk it in and scoop up a huge pile of clear, squishy marbles. It’s immensely satisfying, like
ponddipping for magic frogspawn, and I want to reach in with my hand for an invisible handful of the squeezy shapes. Luckily for me, this sort of messy visitor interaction is perfectly acceptable, and people can even take home their own free vial of invisible sphere and water.
I ask if it is the shape of the object which causes them to vanish in water.
Ulf explains it's not the shape that matters, but the substance. The objects are made out of a material matches the water’s refractive index, which is the amount that light is bent when passing through an object. Light passing through the water also passes through the spheres and cubes without being scattered or reflected. If the objects were dropped into another liquid of a different refractive index, then I would be able to see them.
This is the science behind the Invisible Man a man who could change his own body cells to match the refractive index of air.
Further along the stall, I see a low table spattered with messy pieces of clear jelly shapes. They have an alluring and eerie blue glow in the stall’s lighting, and I have to investigate. Another scientist, Joanna, shows me how the shapes, which are made from simple kitchen jelly, refract and
bend a ray of light shot from a laser pointer. The ray is sent on a journey of zigzagging angles across the table.
I can’t help it. She’s wielding a glowing laser pointer like a wand, and the whole team are wearing academic gowns that look like splendid flapping black robes. They’re bending rays of coloured light and casually vanishing solid shapes in liquids. Forget today's premiere of Harry Potter. Right now these people are the closest things to true wizards in the whole of London! I have to ask about invisibility cloaks.
“I think we’re a long way from anything like a Harry Potterstyle Invisibility Cloak,” Joanna says with a sympathetic smile. She shows me how the jelly bends red light differently to green light, because of their different wavelengths. This is why white light passing through a glass prism spreads out into separate colours. A true invisibility cloak would need to refract all the different wavelengths of light in the same way.
Still, this stall shows the possibilities of bending light, and explains the science behind the fibre optic technology revolution of the past few decades. The more we learn about how to manipulate light, the more we can use it. We'll have to wait and see- or try to see- what the future holds.
Blog article about a cafe scientifique event on String Theory
Originally posted here
http://blogs.royalsociety.org/sciencelive/2011/07/20/acafeofstringandscience/
A Cafe of String and Science
Who wants to know about string theory? Judging from the packed tent at the 2011 Royal Society Summer Science Exhibition, the answer is a lot of people!
The first Cafe Scientifique of the week drew a tent full of people to hear Dr. David Tong, Research Fellow of the Royal Society and theoretical physicist of Cambridge University, deliver an energetic introduction to the strangely named theory. Prior to the event, Dr. Tong admitted he had never done a Cafe Scientifique before, but was looking forward to the experience and hoped he could deliver a broad understanding of what string theory was, and how it may be explored in the near future.
The event was hosted by space scientist Dr. Maggie Alderin-Pocock, who deftly directed dialogue while handling her lively young toddler. Asked to describe her impression of Cafe Scientifique events, Dr. Maggie said she enjoyed the informal nature and interaction in the events and was looking forward to learning about string theory herself.
Dr. Tong began the event by tackling what string theory was, how it related to other areas of physics, and what developments we could look forward to in the future, thanks to the Large Hadron Collider. He gave a neat summary of string theory’s fundamental postulate “If you could look inside any particle really closely, as far down as you could what you would find is a single loop of string,” and explained that according to the theory, different fundamental particles of matter were the result of different ranges of string vibrations.
An audience member asked what the string was made out of. Dr. Tong gave him three possibilities fundamental building blocks, infinitely smaller particles, or simply pure energy.
String theory gained a colourful personality as Dr. Tong described it variously as “a speculative but highly promising idea for the ultimate laws of physics”, a “fairly ludicrous idea” born in the ‘70s, the mathematical product of around 15 years challenging work, and most strikingly “A tiny equation that contains every law of physics that mankind has ever discovered throughout history.” The theory combines physics theories and is the next step from the Standard Model of particle physics, which outlines the motions and properties of particles. The Standard Model was also personalised by Dr. Tong as “The pinnacle of scientific achievement, marred only by a bland name!”
But is string theory too good to be true? Dr. Tong confessed that in part, this has always been the case. Although the mathematics behind this conceptually vivid theory works well, the inability to experimentally test string theory has always been an enduring problem.
Nonetheless, he pointed out that it was the Ancient Greeks who had first proposed the existence of atoms, which have only become visible in the modern age of powerful scanning microscopes. This brought us nicely to the topic of the world's latest piece of scientific kit and technological crowning glory, the Large Hadron Collider.
One of the most striking predictions of string theory is that there are extra dimensions in our world and if so, the Large Hadron Collider is expected to show evidence of them. Reassuringly, Dr. Tong said he felt confident that the LHC would produce exciting evidence for or against string theory within one or two years.
Though Dr. Tong confessed that he believed string theory was missing some key elements, he also described it as the only credible solution to dark energy, which accounts for 75% of energy in the universe and which is currently hidden. As an aside on that topic, Dr. Tong cheerfully admitted that the current quantum theory has its own calculations and candidates for dark energy, but that calculations come out wrong by, oh, roughly 20 billion...
He also described an exciting and alternative theory to look for evidence of strings, a theory which he had helped personally develop. Extreme conditions are needed to see strings, and the collisions of the LHC will not be strong enough to make strings themselves visible. So what about the Big Bang? Dr. Tong explained that the extra dimensions of string theory may be visible in the ‘fireball’ imprint of the Big Bang, otherwise known as cosmic background radiation, and this is measurable by satellite in exquisite detail. The evidence for this theory could be being collected right now by the recently launched Planck satellite, currently 3 million kilometres from Earth.
“There’s something kind of miraculous about this. That someone like me can sit in an office with a pen and paper musing about what happened 13.7 billion years ago, but we actually know whether this is right or wrong,” Dr. Tong commented happily, touching right on one of the best points of modern physics.
An audience member questioned if strings might have been caught and stretched out across the universe during the Big Bang explosion and the answer was yes. One day, they may be discovered just like this.
Further questions probed the nature of the extra dimensions...
"Current thinking says there are 10 or 11..."
...what the Higgs boson actually is...
"Invisible treacle’ that slows down particles and generates mass."
...and whether string theory has anything to add on the philosophical question of free will?
"No."
There was no question was too challenging for an honest answer. One member of the audience asked what had existed before the Big Bang.
Dr. Tong answered without hesitation. “That’s easy to answer. We have no idea!”
Expounding further on this, Dr. Tong rearranged the common perception of the Big Bang Theory. The theory outlines the sudden expansion of the universe 13.7 billion years ago, but it doesn’t say what started it, or why it happened. Tantalisingly, it could be string theory which will answer those questions.
Time ran out before the questions could, but Dr. Tong was content to remain behind and chat further.
“I’ll happily stay behind until I’ve exhausted you all,” he said cheerfully, and the eager crowd moved in
Originally posted here
http://blogs.royalsociety.org/sciencelive/2011/07/20/acafeofstringandscience/
A Cafe of String and Science
Who wants to know about string theory? Judging from the packed tent at the 2011 Royal Society Summer Science Exhibition, the answer is a lot of people!
The first Cafe Scientifique of the week drew a tent full of people to hear Dr. David Tong, Research Fellow of the Royal Society and theoretical physicist of Cambridge University, deliver an energetic introduction to the strangely named theory. Prior to the event, Dr. Tong admitted he had never done a Cafe Scientifique before, but was looking forward to the experience and hoped he could deliver a broad understanding of what string theory was, and how it may be explored in the near future.
The event was hosted by space scientist Dr. Maggie Alderin-Pocock, who deftly directed dialogue while handling her lively young toddler. Asked to describe her impression of Cafe Scientifique events, Dr. Maggie said she enjoyed the informal nature and interaction in the events and was looking forward to learning about string theory herself.
Dr. Tong began the event by tackling what string theory was, how it related to other areas of physics, and what developments we could look forward to in the future, thanks to the Large Hadron Collider. He gave a neat summary of string theory’s fundamental postulate “If you could look inside any particle really closely, as far down as you could what you would find is a single loop of string,” and explained that according to the theory, different fundamental particles of matter were the result of different ranges of string vibrations.
An audience member asked what the string was made out of. Dr. Tong gave him three possibilities fundamental building blocks, infinitely smaller particles, or simply pure energy.
String theory gained a colourful personality as Dr. Tong described it variously as “a speculative but highly promising idea for the ultimate laws of physics”, a “fairly ludicrous idea” born in the ‘70s, the mathematical product of around 15 years challenging work, and most strikingly “A tiny equation that contains every law of physics that mankind has ever discovered throughout history.” The theory combines physics theories and is the next step from the Standard Model of particle physics, which outlines the motions and properties of particles. The Standard Model was also personalised by Dr. Tong as “The pinnacle of scientific achievement, marred only by a bland name!”
But is string theory too good to be true? Dr. Tong confessed that in part, this has always been the case. Although the mathematics behind this conceptually vivid theory works well, the inability to experimentally test string theory has always been an enduring problem.
Nonetheless, he pointed out that it was the Ancient Greeks who had first proposed the existence of atoms, which have only become visible in the modern age of powerful scanning microscopes. This brought us nicely to the topic of the world's latest piece of scientific kit and technological crowning glory, the Large Hadron Collider.
One of the most striking predictions of string theory is that there are extra dimensions in our world and if so, the Large Hadron Collider is expected to show evidence of them. Reassuringly, Dr. Tong said he felt confident that the LHC would produce exciting evidence for or against string theory within one or two years.
Though Dr. Tong confessed that he believed string theory was missing some key elements, he also described it as the only credible solution to dark energy, which accounts for 75% of energy in the universe and which is currently hidden. As an aside on that topic, Dr. Tong cheerfully admitted that the current quantum theory has its own calculations and candidates for dark energy, but that calculations come out wrong by, oh, roughly 20 billion...
He also described an exciting and alternative theory to look for evidence of strings, a theory which he had helped personally develop. Extreme conditions are needed to see strings, and the collisions of the LHC will not be strong enough to make strings themselves visible. So what about the Big Bang? Dr. Tong explained that the extra dimensions of string theory may be visible in the ‘fireball’ imprint of the Big Bang, otherwise known as cosmic background radiation, and this is measurable by satellite in exquisite detail. The evidence for this theory could be being collected right now by the recently launched Planck satellite, currently 3 million kilometres from Earth.
“There’s something kind of miraculous about this. That someone like me can sit in an office with a pen and paper musing about what happened 13.7 billion years ago, but we actually know whether this is right or wrong,” Dr. Tong commented happily, touching right on one of the best points of modern physics.
An audience member questioned if strings might have been caught and stretched out across the universe during the Big Bang explosion and the answer was yes. One day, they may be discovered just like this.
Further questions probed the nature of the extra dimensions...
"Current thinking says there are 10 or 11..."
...what the Higgs boson actually is...
"Invisible treacle’ that slows down particles and generates mass."
...and whether string theory has anything to add on the philosophical question of free will?
"No."
There was no question was too challenging for an honest answer. One member of the audience asked what had existed before the Big Bang.
Dr. Tong answered without hesitation. “That’s easy to answer. We have no idea!”
Expounding further on this, Dr. Tong rearranged the common perception of the Big Bang Theory. The theory outlines the sudden expansion of the universe 13.7 billion years ago, but it doesn’t say what started it, or why it happened. Tantalisingly, it could be string theory which will answer those questions.
Time ran out before the questions could, but Dr. Tong was content to remain behind and chat further.
“I’ll happily stay behind until I’ve exhausted you all,” he said cheerfully, and the eager crowd moved in
Understanding Animal Research
Stem cell transplant trial for early MS sufferers yields promising results
[Originally published at http://www.animalresearch.info/es/avances-medicos/23/multiple-sclerosis/#drugs]
Multiple sclerosis (MS) is caused by the destruction of the Schwann cells, which form the fatty myelin sheath surrounding nerves, by the cells of the immune system. This autoimmune disease affects about 85,000 people in the UK and a million people worldwide, making it the most common disabling neurological disorder currently affecting young adults.
In MS the white cells of a person’s immune system wrongfully attack and destroy normal cells of the body. They are able to cross the protective blood-brain barrier, and attack the protective fatty sheaths of the brain's neurons. The destruction of the fat layers causes incorrect transmission of nerve impulses between neurons, which manifest as physical symptoms of fatigue, muscle weakness and spasms, difficulties with eyesight, speech, and swallowing, and depression. Sufferers usually begin by entering a relapsing-remitting phase of 10-15 years, during which they experience periods of symptoms followed by apparent recovery. However, as the disease progresses into the secondary and primary phase, the individual experiences worsening symptoms with no remission. Currently, there is no cure.
Experimental autoimmune encephalitis
To develop treatments for MS, researchers use experimental autoimmune encephalomyelitis (EAE) mice, first described 50 years ago as a highly important model of inflammatory CNS autoimmune disease. Using this model, researchers can produce acute, chronic, and relapsing-remitting EAE models to trial MS treatment. The model also study of the disease‘s nature . Like other autoimmune diseases, it is thought that MS can be induced by a viral infection. This theory has been supported by animal studies, and makes the EAE model especially suitable as the condition caused by a virus. Revealing the cause of the disease may help us to understand its transmission and early development, as well as improving the efficacy of treatment.
Stem cells and transplants
An emerging potential treatment is to actually remove these ‘self-reactive’ lymphocytes, and replace them with lymphocytes developed from the patient’s own stem cells. In effect, this is a recalibration of the person’s immune system which removes the abnormal aspects and transplants their own immune cells back into the body. Because the replenishing white cells are developed from the patient’s own stem cells, they do not induce the usual problems of rejection .
In a study published in the Lancet, researchers recruited 21 sufferers in the relapsing-remitting phase of MS who had not responded to traditional treatment. They used a low-intensity treatment to remove the patients’ self-reactive white cells. New white cells were developed from stem cells taken from the patient’s bone marrow, and transplanted back into the body. After an average period of 3 years, 81% of patients showed improvement of physical disabilities, and 100% showed disease stabilisation.[1]
The use of HSCT (Hematopoietic stem cell transplantation) to treat autoimmune disorders was first considered following observations of autoimmune disease remission when bone marrow tissue was destroyed during cancer therapy. As researchers found that bone marrow transplants could induce either resistance or susceptibility to autoimmune diseases , and realised that the bone marrow cells were key to the development of such diseases. However, the destruction of bone marrow was an aggressive treatment regime which severely depleted the patient’s immune system. Using the animal model, researchers were able to conclude that bone marrow transplants were a viable treatment for MS, but that severe depletion of lymphocytes also raised the mortality risk [2]. These results led to the development of less aggressive conditioning regimes which would be safer for human patients.
Comparing animal and human study results has revealed that human autoimmune diseases are caused by multiple underlying factors. Animal models have shown genetic factors to be strongly influential, whereas in humans, it is suggested that environmental factors may be key to the development of the disease. Researchers are also using animal models to further investigate whether the source of the HSCT should be the individual concerned, or a donor[3].
Future research will focus on assessing the latest breakthrough treatment further in a larger, randomized study of 100 human volunteers, and the intensity of the immunosuppression required to reduce risks of secondary infections. Professor Richard Burt, the leader of the study, said this treatment was not a cure, but a way of "changing the natural history of the disease", while Dr Doug Brown, Research Manager at the MS Society, hailed the results as ‘encouraging’ and said- “Stem cells are showing more and more potential in the treatment of MS and the challenge we now face is proving their effectiveness in trials involving large numbers of people.”[4].
References
[1.] Burt RK, Loh Y, Cohen B, et al. Autologous non-myeloablative haemopoietic stem cell transplantation in relapsing-remitting multiple sclerosis: a phase I/II study. Lancet Neurol 2009; published online January 30.
[2.] Burt RK, Traynor AE. Hematopoietic stem cell transplantation: a new therapy for autoimmune disease. Oncologist. 1999;4(1):77-83
[3.] Sykes M, Nikolic B. Treatment of severe autoimmune disease by stem-cell transplantation. Nature. 2005 Jun 2;435(7042):620-7. Review.
[4.] MS Society, 2009. Stem cell therapy may halt and even reverse disability in people with relapsing remitting MS. (Research News) [Online] (Updated 30 Jan 09). Available at: http://www.mssociety.org.uk/research/news_in_research/research_news/stem_cell_trial.html
Other links
Animation explaining treatment of MS using stem cells: http://www.sumanasinc.com/webcontent/animations/content/nmss_stemcells.htmlGeneral information about stem cells and areas of researchhttp://www.explorestemcells.co.uk/
Stem cell transplant trial for early MS sufferers yields promising results
[Originally published at http://www.animalresearch.info/es/avances-medicos/23/multiple-sclerosis/#drugs]
Multiple sclerosis (MS) is caused by the destruction of the Schwann cells, which form the fatty myelin sheath surrounding nerves, by the cells of the immune system. This autoimmune disease affects about 85,000 people in the UK and a million people worldwide, making it the most common disabling neurological disorder currently affecting young adults.
In MS the white cells of a person’s immune system wrongfully attack and destroy normal cells of the body. They are able to cross the protective blood-brain barrier, and attack the protective fatty sheaths of the brain's neurons. The destruction of the fat layers causes incorrect transmission of nerve impulses between neurons, which manifest as physical symptoms of fatigue, muscle weakness and spasms, difficulties with eyesight, speech, and swallowing, and depression. Sufferers usually begin by entering a relapsing-remitting phase of 10-15 years, during which they experience periods of symptoms followed by apparent recovery. However, as the disease progresses into the secondary and primary phase, the individual experiences worsening symptoms with no remission. Currently, there is no cure.
Experimental autoimmune encephalitis
To develop treatments for MS, researchers use experimental autoimmune encephalomyelitis (EAE) mice, first described 50 years ago as a highly important model of inflammatory CNS autoimmune disease. Using this model, researchers can produce acute, chronic, and relapsing-remitting EAE models to trial MS treatment. The model also study of the disease‘s nature . Like other autoimmune diseases, it is thought that MS can be induced by a viral infection. This theory has been supported by animal studies, and makes the EAE model especially suitable as the condition caused by a virus. Revealing the cause of the disease may help us to understand its transmission and early development, as well as improving the efficacy of treatment.
Stem cells and transplants
An emerging potential treatment is to actually remove these ‘self-reactive’ lymphocytes, and replace them with lymphocytes developed from the patient’s own stem cells. In effect, this is a recalibration of the person’s immune system which removes the abnormal aspects and transplants their own immune cells back into the body. Because the replenishing white cells are developed from the patient’s own stem cells, they do not induce the usual problems of rejection .
In a study published in the Lancet, researchers recruited 21 sufferers in the relapsing-remitting phase of MS who had not responded to traditional treatment. They used a low-intensity treatment to remove the patients’ self-reactive white cells. New white cells were developed from stem cells taken from the patient’s bone marrow, and transplanted back into the body. After an average period of 3 years, 81% of patients showed improvement of physical disabilities, and 100% showed disease stabilisation.[1]
The use of HSCT (Hematopoietic stem cell transplantation) to treat autoimmune disorders was first considered following observations of autoimmune disease remission when bone marrow tissue was destroyed during cancer therapy. As researchers found that bone marrow transplants could induce either resistance or susceptibility to autoimmune diseases , and realised that the bone marrow cells were key to the development of such diseases. However, the destruction of bone marrow was an aggressive treatment regime which severely depleted the patient’s immune system. Using the animal model, researchers were able to conclude that bone marrow transplants were a viable treatment for MS, but that severe depletion of lymphocytes also raised the mortality risk [2]. These results led to the development of less aggressive conditioning regimes which would be safer for human patients.
Comparing animal and human study results has revealed that human autoimmune diseases are caused by multiple underlying factors. Animal models have shown genetic factors to be strongly influential, whereas in humans, it is suggested that environmental factors may be key to the development of the disease. Researchers are also using animal models to further investigate whether the source of the HSCT should be the individual concerned, or a donor[3].
Future research will focus on assessing the latest breakthrough treatment further in a larger, randomized study of 100 human volunteers, and the intensity of the immunosuppression required to reduce risks of secondary infections. Professor Richard Burt, the leader of the study, said this treatment was not a cure, but a way of "changing the natural history of the disease", while Dr Doug Brown, Research Manager at the MS Society, hailed the results as ‘encouraging’ and said- “Stem cells are showing more and more potential in the treatment of MS and the challenge we now face is proving their effectiveness in trials involving large numbers of people.”[4].
References
[1.] Burt RK, Loh Y, Cohen B, et al. Autologous non-myeloablative haemopoietic stem cell transplantation in relapsing-remitting multiple sclerosis: a phase I/II study. Lancet Neurol 2009; published online January 30.
[2.] Burt RK, Traynor AE. Hematopoietic stem cell transplantation: a new therapy for autoimmune disease. Oncologist. 1999;4(1):77-83
[3.] Sykes M, Nikolic B. Treatment of severe autoimmune disease by stem-cell transplantation. Nature. 2005 Jun 2;435(7042):620-7. Review.
[4.] MS Society, 2009. Stem cell therapy may halt and even reverse disability in people with relapsing remitting MS. (Research News) [Online] (Updated 30 Jan 09). Available at: http://www.mssociety.org.uk/research/news_in_research/research_news/stem_cell_trial.html
Other links
Animation explaining treatment of MS using stem cells: http://www.sumanasinc.com/webcontent/animations/content/nmss_stemcells.htmlGeneral information about stem cells and areas of researchhttp://www.explorestemcells.co.uk/
Refractive Index
The First Contendors For The Institute of Physics Early Career Communicator Award Published online November 2011
The First Contendors For The Institute of Physics Early Career Communicator Award Published online November 2011
I, Science, the science magazine of Imperial College London
The Exxon, the Venter, and the Algae
[Originally published on 17 November 2009, for www.conservationtoday.org ]
"There is really nothing ExxonMobil can bring to that whole biofuels issue. We don't see a direct role for ourselves with today's technology."
Rex Tillerman, current CEO of Exxon-Mobil, speaking at Oil Day, Feb 13, 2007.
One is the largest of the non-state owned energy companies, owner of 38 oil refineries in 21 countries, and of an environmental rights record blackened by spills, fines and climate-scepticism.
Another is a prominent cell biologist who ran a privately funded rival project to the official Human Genome Project, successfully built an artificial chromosome in 2007, and aspires to create synthetic life in the near future.
The last are tiny, green, non-sentient, and were the original creators of the oxygen-rich atmosphere that we enjoy on our planet.
Now, these three forces are coming together to combat the problems of dwindling petroleum, the drive for cleaner fuel, and the climate-change inducing problem of carbon emissions. Exxon-Mobil will provide the money. Craig Venter will provide the science. Algae, ultimately, will provide us with biofuel.
In July 2009, the energy corporation signed a $600 billion dollar multi-year partnership with Venter’s biotechnology company, Synthetic Genomes, which is the largest and most serious investment that has been made, so far, in the field of commercial algae biofuel. Yet which one will Exxon benefit from more- profitable, green biofuel, or publicity?
The Algae
Biofuel has been slowly edging its way into modern fuel and energy policies, yet the problems of biofuel production are becoming rather well known. The term ‘biofuel’ can refer to bio-ethanol, an alcohol which substitutes for petrol, or biodiesel, or biogas, or any form of biological, combustible material, usually derived from plants. If a plant was grown to be a biofuel, and burned, it would release only the carbon that was absorbed during its lifetime, making it effectively carbon-neutral. Whereas burning reserves of coal, oil, or gas releases carbon stores that were built up over the long history of the Earth.
But growing crops for fuel takes away arable land which could be used to grow food, and converting crops into fuel raises food prices. This has a particularly negative effect in developing countries, where those living in poverty already struggle to reach the daily recommended calorie intake. Deforestation to generate land quashes local biodiversity. Economically, when subtracting the time, money, and energy invested in growing, processing, and extraction, biofuels can be expensive to produce. Ironically, for the same reasons, they may not be markedly carbon-neutral, either.
All in all, these factors give biofuels a dappled image. They are still a poorer economic choice than petroleum. Yet in principle, they are more ethical and environmentally-friendly than burning coal, petroleum oil, or gas. Crucially, they are also a renewable fuel, which means we will surely be forced to rely on them more and more to meet the world’s growing energy demand.
The problems of biofuels are reflected in the reluctant integration of biofuels into commercial and political policies. Mixes of biofuel and petroleum fuel are available, yet hardly widespread. In 2007 the EU declared they would increase the share of biofuels used in transport to 10% by 2020. This figure was reduced to 6% in 2008, owing to fears of a food crisis. A similar story played out in the UK, where the proposed rise of a 5% required biofuel content in petrol was changed from 2.5% to 3.3% this year.
Corn, oil palm, and soybean have become the main biofuel crops, because of the existing global infrastructure to farm these crops, and the amount of fuel that can be extracted from them. Yet any organic material that can be made to yield combustible matter is a form of biofuel, and this is not limited to the higher plants.
Algae do not need arable land to grow on. Like other plants, they require carbon dioxide, sunlight, water, and management, but they could grow suspended in tanks of water over any terrain. They can reproduce rapidly- some strains divide every few hours. They produce and store oil- some strains can produce oil yields of 20-50% of their bodyweight. Compare this to soy bean, one of the most prominent biofuel crops, which produces an oil yield of 20% of its bodyweight. Finally, the remaining unknown species of algae are so vast that their number defies accurate estimates. Even hardier, even higher yielding species could exist, somewhere.
In recent years, with more pressure and funding into alternative fuel research, scientists have begun to seriously study their biofuel potential. This potential appears, to say the very least, encouraging. Conservative estimates of algal biofuel production provide figures such as 30,000 - 50,000 litres of oil per hectare per year, compared to the 1,300 - 2,400 per hectare per year for typical biofuel crops. Because the plants would grow well when supplied with concentrated carbon dioxide and nitrogen oxide, algae biofuel refineries could be built alongside current power plants to make use of their waste gases. The remaining dry weight of the algae could be used as fertiliser, feedstock, or burnable fuel.
Algae biofuel clearly has a lot of potential, but potential requires development. This form of biofuel has not been developed to a point where it could compete commercially with petroleum fuel- the FT estimate for producing algae biofuel in July 2009 was set at $33 per gallon, compared to the $2 per gallon of Middle-East crude oil.
How could this gap be lessened? Answers include cost-effective government policies, lower taxes, waiting for the inevitable rise of petroleum prices, and improving the way in which the algae are grown and harvested.
However, the best answer would be to increasing the algae oil yield, and this is where Venter and Exxon-Mobil come in. Algae species could be genetically engineered to increase their oil yield. This will take many years of research and development, but it is a task which Craig Venter is determined to undertake.
The Scientist
Craig Venter is a cell biologist who has become well known through some impressive and controversial scientific achievements. Applying himself to formal study of science after a short tour of duty in the Vietnam War, he achieved recognition and success through his progressive work in enzyme and genetics sequencing. But Venter really hit the headlines in 1998, when he was hired by Celera Genomics to provide a rival sequencing effort to the public-funded Human Genome Project. At that time, the Human Genome Project was three years into a 10-year plan, with a planned cost of $5 billion dollars. Venter boldly claimed that he could complete the genome in a fraction of that time, and a fraction of that cost. At a time when no one could quite decide what would be permissible for patents, Celera Genomics also proposed to commercialise parts of the human genome, a move which attracted fierce criticism. Eventually, the White House stepped in to order the two projects to make a joint announcement of the completed genome, and to make it freely available for scientific research.
Although painted by some as arrogant, profit-driven, and a ‘maverick scientist’, there are quite a few points in Venter’s favour. He actually was able to sequence a human genome at a lower cost and lower timeframe, as he had done before with a bacterial genome. Successful scientists in general, it must be said, are rarely known for being shrinking violets. Venter insists he was fired by Celera Genomics after the completion of the genome, because he assisted in making the genome publicly available. Venter claims he is in science for the science, not the money, and that his decisions to work for private companies are solely based on his desire for funding.
In 2006 he opened the non-profit genomics research company, J. Craig Venter Institute, and in 2005 he co-founded Synthetic Genomes, a privately-funded biotechnology company. Unlike academic research laboratories, the company is not reliant on public funding, or academic regulations. It is this company which will focus on developing algae biofuel.
The Investors
Exxon-Mobil’s investment has dwarfed all previous investments into developing algae biofuel. Other prominent investors have included the UK government, who provided the independent company The Carbon Trust with £4 million of funding in 2008, for an Algae Biofuels Challenge. This aims to commercialise an algae-oil based biodiesel by 2020. In 2008, the U.S. military also signed two deals worth $35 million to develop algae biofuel. Meanwhile, a handful of independent algae biofuel companies have developed here and there throughout the US.
But critics suggest this latest move from Exxon serves a dual ploy. Environmentalists have labelled Exxon as one of the least progressive of the major oil companies, because they have little history of worthwhile investments in alternative energy sources. Exxon already spends over $600 million a year on basic research. Yet each year it makes tens of billions of dollars of profit. In 2008, it made a record-breaking profit of $40.16 billion. Against such figures, their investment in algal biofuel is a meagre drop of their money.
The most prolonged source of discontent about Exxon comes from their funding of climate change denial groups. According to a 2007 report from the (bluntly named) Union of Concerned Scientists, ExxonMobil has funneled nearly $16 million between 1998 and 2005 to a network of 43 advocacy organizations which "seek to confuse the public on global warming science". Unfavourable comparisons were drawn by the Royal Society, between Exxon's choice of funding, and the shady tactics of the tobacco industry in the 19th century, who sought to deny and disguise the link between smoking and cancer. Despite declaring they would cease funding for some such organisations in 2006, Exxon continued to fund over 40 climate sceptic groups till almost 2008. Consequently, critics say that this latest deal may serve more to greenwash the tarnished environmental reputation of the corporation.
Indeed, Exxon's pattern of denial and acknowledgement of the climate change problem has been confusing. In 2007 Exxon's vice-president for public affairs, Kenneth Cohen, said that the corporation was aware now "...that the risk is serious and action should be taken.". Whereas his predecessor Lee Raymond had staunchly denied climate change, the current CEO, Rex Tillerson, both publicly acknowledged man-made global warming while declaring there would be no alternative to the continuing and growing dominance of oil and gas into the future. The corporation was detached from the problem, and as for biofuels- well, what about biofuels?
In a July 2009 letter to The Guardian, Nick Thomas, the director of corporate affairs for ExxonMobil, protested against reports of his corporation’s continual funding of climate deniers, saying that this funding was only intended to promote discussion on issues relevant to ExxonMobil, and that obviously the corporation had no control over what such organisations eventually had to say. He also added ExxonMobil was currently researching emission-reducing car technology, sponsoring alternative ‘breakthrough research’ in solar power as well as biofuels, and putting $100 million into technology to separate carbon dioxide from natural gas. This is fortunate news, as it has been estimated by the Union of Concerned Scientists that company operations alone expel over 135 million metric tons of carbon dioxide into the atmosphere each year, plus the likes of, for example, an estimated total combustion production of 1,047 million metric tons of carbon-dioxide equivalent emissions in 2005.
Venter has already described hopes of genetically engineering the algae to actively pump out oil, so that harvesting the oil will not kill the algae. This is in contrast to other approaches to algal biofuel, which have focused on improving the efficiency of growth, maintenance, and extraction. When asked if he was concerned regarding Exxon’s poor environmental record, he replied that such a change in fuel type could not happen without the oil industry. "They have a reputation for studying things for quite a while and acting in a large fashion once they become convinced of an approach,” Venter said, in a July interview to New Scientist. “I don't see how it can be bad news if somebody makes a major change in direction for the benefit of the planet."
If Venter succeeds and patents his genetic work, this will surely give Exxon a powerful position on the market for future algae biofuel. Yet it is true that, while they will benefit in profit, the world could benefit immeasurably from carbon-neutral biofuel. For all of their mixed reputations, the world will be watching Venter, Exxon, and the algae with interest- and hope.
Bibliography:
Chisti, Y. (2007) Biodiesel from microalgae. Biotech Adv (25) pp. 294-306
Li et al., (2008) Biofuels from microalgae. Biotech Prog 24 (4) pp. 815-20
Schubert, C. (2006) Can biofuels finally take centre stage? Nature Biotech 24 pp.777-784
Williams, P.J (2007) Biofuel: microalgae cut the social and ecological costs Nature 450 pp. 478
(Correspondence)
The Exxon, the Venter, and the Algae
[Originally published on 17 November 2009, for www.conservationtoday.org ]
"There is really nothing ExxonMobil can bring to that whole biofuels issue. We don't see a direct role for ourselves with today's technology."
Rex Tillerman, current CEO of Exxon-Mobil, speaking at Oil Day, Feb 13, 2007.
One is the largest of the non-state owned energy companies, owner of 38 oil refineries in 21 countries, and of an environmental rights record blackened by spills, fines and climate-scepticism.
Another is a prominent cell biologist who ran a privately funded rival project to the official Human Genome Project, successfully built an artificial chromosome in 2007, and aspires to create synthetic life in the near future.
The last are tiny, green, non-sentient, and were the original creators of the oxygen-rich atmosphere that we enjoy on our planet.
Now, these three forces are coming together to combat the problems of dwindling petroleum, the drive for cleaner fuel, and the climate-change inducing problem of carbon emissions. Exxon-Mobil will provide the money. Craig Venter will provide the science. Algae, ultimately, will provide us with biofuel.
In July 2009, the energy corporation signed a $600 billion dollar multi-year partnership with Venter’s biotechnology company, Synthetic Genomes, which is the largest and most serious investment that has been made, so far, in the field of commercial algae biofuel. Yet which one will Exxon benefit from more- profitable, green biofuel, or publicity?
The Algae
Biofuel has been slowly edging its way into modern fuel and energy policies, yet the problems of biofuel production are becoming rather well known. The term ‘biofuel’ can refer to bio-ethanol, an alcohol which substitutes for petrol, or biodiesel, or biogas, or any form of biological, combustible material, usually derived from plants. If a plant was grown to be a biofuel, and burned, it would release only the carbon that was absorbed during its lifetime, making it effectively carbon-neutral. Whereas burning reserves of coal, oil, or gas releases carbon stores that were built up over the long history of the Earth.
But growing crops for fuel takes away arable land which could be used to grow food, and converting crops into fuel raises food prices. This has a particularly negative effect in developing countries, where those living in poverty already struggle to reach the daily recommended calorie intake. Deforestation to generate land quashes local biodiversity. Economically, when subtracting the time, money, and energy invested in growing, processing, and extraction, biofuels can be expensive to produce. Ironically, for the same reasons, they may not be markedly carbon-neutral, either.
All in all, these factors give biofuels a dappled image. They are still a poorer economic choice than petroleum. Yet in principle, they are more ethical and environmentally-friendly than burning coal, petroleum oil, or gas. Crucially, they are also a renewable fuel, which means we will surely be forced to rely on them more and more to meet the world’s growing energy demand.
The problems of biofuels are reflected in the reluctant integration of biofuels into commercial and political policies. Mixes of biofuel and petroleum fuel are available, yet hardly widespread. In 2007 the EU declared they would increase the share of biofuels used in transport to 10% by 2020. This figure was reduced to 6% in 2008, owing to fears of a food crisis. A similar story played out in the UK, where the proposed rise of a 5% required biofuel content in petrol was changed from 2.5% to 3.3% this year.
Corn, oil palm, and soybean have become the main biofuel crops, because of the existing global infrastructure to farm these crops, and the amount of fuel that can be extracted from them. Yet any organic material that can be made to yield combustible matter is a form of biofuel, and this is not limited to the higher plants.
Algae do not need arable land to grow on. Like other plants, they require carbon dioxide, sunlight, water, and management, but they could grow suspended in tanks of water over any terrain. They can reproduce rapidly- some strains divide every few hours. They produce and store oil- some strains can produce oil yields of 20-50% of their bodyweight. Compare this to soy bean, one of the most prominent biofuel crops, which produces an oil yield of 20% of its bodyweight. Finally, the remaining unknown species of algae are so vast that their number defies accurate estimates. Even hardier, even higher yielding species could exist, somewhere.
In recent years, with more pressure and funding into alternative fuel research, scientists have begun to seriously study their biofuel potential. This potential appears, to say the very least, encouraging. Conservative estimates of algal biofuel production provide figures such as 30,000 - 50,000 litres of oil per hectare per year, compared to the 1,300 - 2,400 per hectare per year for typical biofuel crops. Because the plants would grow well when supplied with concentrated carbon dioxide and nitrogen oxide, algae biofuel refineries could be built alongside current power plants to make use of their waste gases. The remaining dry weight of the algae could be used as fertiliser, feedstock, or burnable fuel.
Algae biofuel clearly has a lot of potential, but potential requires development. This form of biofuel has not been developed to a point where it could compete commercially with petroleum fuel- the FT estimate for producing algae biofuel in July 2009 was set at $33 per gallon, compared to the $2 per gallon of Middle-East crude oil.
How could this gap be lessened? Answers include cost-effective government policies, lower taxes, waiting for the inevitable rise of petroleum prices, and improving the way in which the algae are grown and harvested.
However, the best answer would be to increasing the algae oil yield, and this is where Venter and Exxon-Mobil come in. Algae species could be genetically engineered to increase their oil yield. This will take many years of research and development, but it is a task which Craig Venter is determined to undertake.
The Scientist
Craig Venter is a cell biologist who has become well known through some impressive and controversial scientific achievements. Applying himself to formal study of science after a short tour of duty in the Vietnam War, he achieved recognition and success through his progressive work in enzyme and genetics sequencing. But Venter really hit the headlines in 1998, when he was hired by Celera Genomics to provide a rival sequencing effort to the public-funded Human Genome Project. At that time, the Human Genome Project was three years into a 10-year plan, with a planned cost of $5 billion dollars. Venter boldly claimed that he could complete the genome in a fraction of that time, and a fraction of that cost. At a time when no one could quite decide what would be permissible for patents, Celera Genomics also proposed to commercialise parts of the human genome, a move which attracted fierce criticism. Eventually, the White House stepped in to order the two projects to make a joint announcement of the completed genome, and to make it freely available for scientific research.
Although painted by some as arrogant, profit-driven, and a ‘maverick scientist’, there are quite a few points in Venter’s favour. He actually was able to sequence a human genome at a lower cost and lower timeframe, as he had done before with a bacterial genome. Successful scientists in general, it must be said, are rarely known for being shrinking violets. Venter insists he was fired by Celera Genomics after the completion of the genome, because he assisted in making the genome publicly available. Venter claims he is in science for the science, not the money, and that his decisions to work for private companies are solely based on his desire for funding.
In 2006 he opened the non-profit genomics research company, J. Craig Venter Institute, and in 2005 he co-founded Synthetic Genomes, a privately-funded biotechnology company. Unlike academic research laboratories, the company is not reliant on public funding, or academic regulations. It is this company which will focus on developing algae biofuel.
The Investors
Exxon-Mobil’s investment has dwarfed all previous investments into developing algae biofuel. Other prominent investors have included the UK government, who provided the independent company The Carbon Trust with £4 million of funding in 2008, for an Algae Biofuels Challenge. This aims to commercialise an algae-oil based biodiesel by 2020. In 2008, the U.S. military also signed two deals worth $35 million to develop algae biofuel. Meanwhile, a handful of independent algae biofuel companies have developed here and there throughout the US.
But critics suggest this latest move from Exxon serves a dual ploy. Environmentalists have labelled Exxon as one of the least progressive of the major oil companies, because they have little history of worthwhile investments in alternative energy sources. Exxon already spends over $600 million a year on basic research. Yet each year it makes tens of billions of dollars of profit. In 2008, it made a record-breaking profit of $40.16 billion. Against such figures, their investment in algal biofuel is a meagre drop of their money.
The most prolonged source of discontent about Exxon comes from their funding of climate change denial groups. According to a 2007 report from the (bluntly named) Union of Concerned Scientists, ExxonMobil has funneled nearly $16 million between 1998 and 2005 to a network of 43 advocacy organizations which "seek to confuse the public on global warming science". Unfavourable comparisons were drawn by the Royal Society, between Exxon's choice of funding, and the shady tactics of the tobacco industry in the 19th century, who sought to deny and disguise the link between smoking and cancer. Despite declaring they would cease funding for some such organisations in 2006, Exxon continued to fund over 40 climate sceptic groups till almost 2008. Consequently, critics say that this latest deal may serve more to greenwash the tarnished environmental reputation of the corporation.
Indeed, Exxon's pattern of denial and acknowledgement of the climate change problem has been confusing. In 2007 Exxon's vice-president for public affairs, Kenneth Cohen, said that the corporation was aware now "...that the risk is serious and action should be taken.". Whereas his predecessor Lee Raymond had staunchly denied climate change, the current CEO, Rex Tillerson, both publicly acknowledged man-made global warming while declaring there would be no alternative to the continuing and growing dominance of oil and gas into the future. The corporation was detached from the problem, and as for biofuels- well, what about biofuels?
In a July 2009 letter to The Guardian, Nick Thomas, the director of corporate affairs for ExxonMobil, protested against reports of his corporation’s continual funding of climate deniers, saying that this funding was only intended to promote discussion on issues relevant to ExxonMobil, and that obviously the corporation had no control over what such organisations eventually had to say. He also added ExxonMobil was currently researching emission-reducing car technology, sponsoring alternative ‘breakthrough research’ in solar power as well as biofuels, and putting $100 million into technology to separate carbon dioxide from natural gas. This is fortunate news, as it has been estimated by the Union of Concerned Scientists that company operations alone expel over 135 million metric tons of carbon dioxide into the atmosphere each year, plus the likes of, for example, an estimated total combustion production of 1,047 million metric tons of carbon-dioxide equivalent emissions in 2005.
Venter has already described hopes of genetically engineering the algae to actively pump out oil, so that harvesting the oil will not kill the algae. This is in contrast to other approaches to algal biofuel, which have focused on improving the efficiency of growth, maintenance, and extraction. When asked if he was concerned regarding Exxon’s poor environmental record, he replied that such a change in fuel type could not happen without the oil industry. "They have a reputation for studying things for quite a while and acting in a large fashion once they become convinced of an approach,” Venter said, in a July interview to New Scientist. “I don't see how it can be bad news if somebody makes a major change in direction for the benefit of the planet."
If Venter succeeds and patents his genetic work, this will surely give Exxon a powerful position on the market for future algae biofuel. Yet it is true that, while they will benefit in profit, the world could benefit immeasurably from carbon-neutral biofuel. For all of their mixed reputations, the world will be watching Venter, Exxon, and the algae with interest- and hope.
Bibliography:
Chisti, Y. (2007) Biodiesel from microalgae. Biotech Adv (25) pp. 294-306
Li et al., (2008) Biofuels from microalgae. Biotech Prog 24 (4) pp. 815-20
Schubert, C. (2006) Can biofuels finally take centre stage? Nature Biotech 24 pp.777-784
Williams, P.J (2007) Biofuel: microalgae cut the social and ecological costs Nature 450 pp. 478
(Correspondence)
