A QUANTUM OF SCIENCE
"Green power" takes on a whole new meaning
Researchers at the University of Washington have discovered a way to "tap" the small but renewable electrical currents found in trees by investigators at MIT in 2008. Usually these microcurrents (200 millvolts or less) would be incapable of running even small circuits, but electrical engineers from the UW have built special "boost converters" that take a low incoming voltage and store it to produce a greater output.
This is an entirely new and very exciting field where much is currently unknown but the potential exists for a wide range of low-voltage devices that might one day help with everything from early wildfire alerts to climate-change sensors to methods for measuring tree vitality.
For more information:
News article from the UW
Source of Sustained Voltage Difference between the Xylem of a Potted Ficus benjamina Tree and Its Soil (Love et al, 2008)
© AQOS / P. Smalley (2009)
Reproduction with attribution is appreciation
Wednesday, September 9, 2009
Genetic Pastorale
A QUANTUM OF SCIENCE
Are cows responsible for the spread of a gene allowing humans to digest their milk?
Lactase is an enzyme that breaks down lactose, the disaccharide found in cow milk, into glucose and galactose.
This is important because lactose itself cannot serve as a source of energy for the human body, but glucose and galactose can. The gene encoding lactase can have either one or two copies and still produce enough lactase for carriers to process milk – humans lacking a copy cannot digest cow milk and are called lactose intolerant. Another term, "lactase persistence," refers to the strange stubbornness of the lactase gene, which is inherited in some human populations with far more frequency and fidelity than in other human populations.
Now a new publication shows statistical attempts to model the spread of lactase persistence in European populations as a correlate with how common dairying – raising cows for their milk – is in that region over the last, say, ten thousand years.
While it might seem intuitively obvious that intensive dairying would provide a strong selective pressure for a gene that makes cow milk digestible, this model shows exactly how strong that pressure is. Think about it this way: dairy cows were first domesticated around 9,000 years ago in the early Neolithic age. Since then, their presence has managed to exert a strong influence on human genetics, making those who raise them and care for them much more able to benefit from their milk. Before cattle were domesticated for milk (as opposed to for meat) there was little advantage for humans to possess even a single copy of the lactase gene; today, there is a sharp genetic profile between human populations associated with dairying and those that are not. This map, taken from the statistical modeling publication, shows how sharp that genetic profile is.
Researchers suggest, based on this model, that lactase persistence originated somewhere in the red area on the map around 7,500 years ago. This matches archeological evidence as well, showing the value of the model for predicting genetic drift over time and distance.
As much as human civilization has impacted the genetic destiny of the cow, the reverse is true as well. This begs the question: how many other creatures in our environment are shaping us, even now? It is easy to believe that Homo sapiens is the apex of the evolutionary ladder, but even the humble cow has some say in our genetic path.
For more information:
The Origins of Lactase Persistence in Europe (Itan et al)
Lactase (Wikipedia article)
Lactose intolerance (Wikipedia article)
© AQOS / P. Smalley (2009)
Reproduction with attribution is appreciation
Are cows responsible for the spread of a gene allowing humans to digest their milk?
Lactase is an enzyme that breaks down lactose, the disaccharide found in cow milk, into glucose and galactose.
This is important because lactose itself cannot serve as a source of energy for the human body, but glucose and galactose can. The gene encoding lactase can have either one or two copies and still produce enough lactase for carriers to process milk – humans lacking a copy cannot digest cow milk and are called lactose intolerant. Another term, "lactase persistence," refers to the strange stubbornness of the lactase gene, which is inherited in some human populations with far more frequency and fidelity than in other human populations.
Now a new publication shows statistical attempts to model the spread of lactase persistence in European populations as a correlate with how common dairying – raising cows for their milk – is in that region over the last, say, ten thousand years.
While it might seem intuitively obvious that intensive dairying would provide a strong selective pressure for a gene that makes cow milk digestible, this model shows exactly how strong that pressure is. Think about it this way: dairy cows were first domesticated around 9,000 years ago in the early Neolithic age. Since then, their presence has managed to exert a strong influence on human genetics, making those who raise them and care for them much more able to benefit from their milk. Before cattle were domesticated for milk (as opposed to for meat) there was little advantage for humans to possess even a single copy of the lactase gene; today, there is a sharp genetic profile between human populations associated with dairying and those that are not. This map, taken from the statistical modeling publication, shows how sharp that genetic profile is.
Researchers suggest, based on this model, that lactase persistence originated somewhere in the red area on the map around 7,500 years ago. This matches archeological evidence as well, showing the value of the model for predicting genetic drift over time and distance.
As much as human civilization has impacted the genetic destiny of the cow, the reverse is true as well. This begs the question: how many other creatures in our environment are shaping us, even now? It is easy to believe that Homo sapiens is the apex of the evolutionary ladder, but even the humble cow has some say in our genetic path.
For more information:
The Origins of Lactase Persistence in Europe (Itan et al)
Lactase (Wikipedia article)
Lactose intolerance (Wikipedia article)
© AQOS / P. Smalley (2009)
Reproduction with attribution is appreciation
Tuesday, August 25, 2009
Cut, cut, cut
A QUANTUM OF SCIENCE
Are HIV rates in the US substantial enough to merit a policy of circumcision?
Following evidence of the protective effect against HIV infection, recent news articles report that the CDC is mulling the idea of endorsing circumcision for all male infants born in the United States. But will it have that much impact?
First, the science: how does circumcision prevent HIV infection? HIV infections occur when the virus gains entry to cells by binding to a protein called CD4, found on the surface of cells. Cell types rich in CD4 are thus easier targets for a successful HIV infection. One such cell type is the Langerhans cell, a part of the primate epidermal tissue related to defending the body against invading microbes. As it happens, primate foreskin is rich in Langerhans cells, meaning plenty of CD4 protein for the AIDS virus to bind to and invade the body. By removing the foreskin through circumcision, an easy point of entry for the virus is blocked.
(Interestingly, CD4-rich Langerhans cells are found in human foreskin and vaginal tissues, but not in oral or rectal tissues. This suggests that HIV infections use a different biochemical route when introduced into the body through those tissues.)
The idea of reducing the risk of contracting HIV through circumcision is far from new. In 1987 a letter was published in the New England Journal of Medicine suggesting exactly that, and studies done in the last fifteen years bear out that theory. While the methods used and areas studied (largely in Africa) varied, the conclusions were so striking that in at least one case a circumcision/HIV infection study was halted years early so the findings could be considered for public policy discussions. Depending on the area studied and the risk factors of those involved in the study, HIV infection rates were found to be as much as 50% lower among circumcised African men than their intact counterparts. Various attempts have been made to expand the conclusions of individual studies through meta-analysis papers and their conclusions found an even greater protective effect of circumcision when those studied were from high-risk populations.
So why not support a policy of encouraging circumcision in the United States? The same studies being reviewed by the CDC have some counterindications that are well worth considering in any kind of policy discussion.
First, the benefits of circumcision are greatly enhanced among high-risk populations. This means that for the average American man (whose risk is far, far lower than the average African man) the benefits are considerably lessened. This could well have something to do with the fact that an estimated 79% of American men are already circumcised – though as rates of circumcision have fallen to around 65% in the most recent surveys, that number is now trending downward. Secondly, use of barrier protection is far more prevalent in America among all demographics, another factor that reduces the positive impact of circumcision protection. Another risk factor related to the need for additional preventative measures against HIV infection – the rate of STDs causing lesions or ulcers, such as herpes or syphilis, which help HIV enter the body during sexual contact – is lower in America than in most African nations, and treatment for those afflictions is considerably more available. Finally, almost all the research done in this area has been performed in Africa. This means there is a possibility that things could be different among Caucasian populations, simply because they are biochemically distinct from non-Caucasians.
The need for additional research is clear. Until scientists can repeat the highly successful African studies in America, Europe, or ideally both – since circumcision is much less common in European nations than in America – the benefits of circumcision for Western populations will remain a question too open for a substantive policy debate to take place.
For more information:
CDC mulls routine circumcision of infants to reduce spread of HIV (NY Daily News, 25-Aug-09)
Circumcision and heterosexual transmission of HIV infection to men. (Fink, 1987)
Comparative investigation of Langerhans' cells and potential receptors for HIV in oral, genitourinary and rectal epithelia. (Hussain, 1995)
Male circumcision and risk of HIV infection in sub-Saharan Africa: a systematic review and meta-analysis. (Weiss, 2000)
Male circumcision for HIV prevention in young men in Kisumu, Kenya. (Bailey, 2007)
Langerhans cells.
© AQOS / P. Smalley (2009)
Reproduction with attribution is appreciation
Are HIV rates in the US substantial enough to merit a policy of circumcision?
Following evidence of the protective effect against HIV infection, recent news articles report that the CDC is mulling the idea of endorsing circumcision for all male infants born in the United States. But will it have that much impact?
First, the science: how does circumcision prevent HIV infection? HIV infections occur when the virus gains entry to cells by binding to a protein called CD4, found on the surface of cells. Cell types rich in CD4 are thus easier targets for a successful HIV infection. One such cell type is the Langerhans cell, a part of the primate epidermal tissue related to defending the body against invading microbes. As it happens, primate foreskin is rich in Langerhans cells, meaning plenty of CD4 protein for the AIDS virus to bind to and invade the body. By removing the foreskin through circumcision, an easy point of entry for the virus is blocked.
(Interestingly, CD4-rich Langerhans cells are found in human foreskin and vaginal tissues, but not in oral or rectal tissues. This suggests that HIV infections use a different biochemical route when introduced into the body through those tissues.)
The idea of reducing the risk of contracting HIV through circumcision is far from new. In 1987 a letter was published in the New England Journal of Medicine suggesting exactly that, and studies done in the last fifteen years bear out that theory. While the methods used and areas studied (largely in Africa) varied, the conclusions were so striking that in at least one case a circumcision/HIV infection study was halted years early so the findings could be considered for public policy discussions. Depending on the area studied and the risk factors of those involved in the study, HIV infection rates were found to be as much as 50% lower among circumcised African men than their intact counterparts. Various attempts have been made to expand the conclusions of individual studies through meta-analysis papers and their conclusions found an even greater protective effect of circumcision when those studied were from high-risk populations.
So why not support a policy of encouraging circumcision in the United States? The same studies being reviewed by the CDC have some counterindications that are well worth considering in any kind of policy discussion.
First, the benefits of circumcision are greatly enhanced among high-risk populations. This means that for the average American man (whose risk is far, far lower than the average African man) the benefits are considerably lessened. This could well have something to do with the fact that an estimated 79% of American men are already circumcised – though as rates of circumcision have fallen to around 65% in the most recent surveys, that number is now trending downward. Secondly, use of barrier protection is far more prevalent in America among all demographics, another factor that reduces the positive impact of circumcision protection. Another risk factor related to the need for additional preventative measures against HIV infection – the rate of STDs causing lesions or ulcers, such as herpes or syphilis, which help HIV enter the body during sexual contact – is lower in America than in most African nations, and treatment for those afflictions is considerably more available. Finally, almost all the research done in this area has been performed in Africa. This means there is a possibility that things could be different among Caucasian populations, simply because they are biochemically distinct from non-Caucasians.
The need for additional research is clear. Until scientists can repeat the highly successful African studies in America, Europe, or ideally both – since circumcision is much less common in European nations than in America – the benefits of circumcision for Western populations will remain a question too open for a substantive policy debate to take place.
For more information:
CDC mulls routine circumcision of infants to reduce spread of HIV (NY Daily News, 25-Aug-09)
Circumcision and heterosexual transmission of HIV infection to men. (Fink, 1987)
Comparative investigation of Langerhans' cells and potential receptors for HIV in oral, genitourinary and rectal epithelia. (Hussain, 1995)
Male circumcision and risk of HIV infection in sub-Saharan Africa: a systematic review and meta-analysis. (Weiss, 2000)
Male circumcision for HIV prevention in young men in Kisumu, Kenya. (Bailey, 2007)
Langerhans cells.
© AQOS / P. Smalley (2009)
Reproduction with attribution is appreciation
Thursday, August 20, 2009
Comets: Interstellar Johnny Appleseeds?
A QUANTUM OF SCIENCE
Are comets the disseminators of the seeds of life?
It was January 2, 2004. The NASA space probe known as Stardust passed through the tail of the Wild-2 comet, five years after the craft was launched on its mission to collect interstellar dust and particle samples from the tail, or coma, of the comet – particles that might well come from beyond Earth’s solar system. A specially-designed collector called an extra low density aerogel was used to capture the particles, and the probe’s camera took high-resolution images of the comet’s nucleus.
On January 15, 2006, the Stardust probe returned to Earth. A sonic boom and a fireball heralded its return over Utah’s Great Salt Lake desert. It was travelling at almost 29,000 miles per hour – the fastest re-entry speed into Earth's atmosphere ever achieved by a man-made object.
Since then, scientists in the Stardust Mission of NASA’s Jet Propulsion Laboratory have been hard at work analyzing the microscopic dust and particles it collected on its seven-year, three billion mile journey. And the results of that analysis are breathtaking.
Some things were expected. Silicate crystals had been predicted based on spectroscopic observations, but their presence confirmed not only those predictions but also the belief that the comet contained matter from outside the solar system.
Even more exciting, organic materials were detected. Astrobiologists have long been aware of aliphatic hydrocarbons (long chains of carbon and hydrogen) diffused throughout space, but the hydrocarbons found in the coma of Wild-2 were much longer than standard interstellar chains, indicating greater complexity. Methylamine and ethylamine, while simple molecules, were an exciting find as well because the nitrogen they contain is essential for life.
But on August 16, 2009, Dr. Jamie Elsila of NASA's Goddard Space Flight Center in Greenbelt, Maryland announced something astonishing. Scientists analyzing the Stardust samples had detected the presence of glycine, the simplest amino acid – and one of the critical building blocks of almost all life on Earth.
Rigorous testing was required in order to confirm this result. Every effort was made to ensure that "earth grime" did not contaminate the samples. The Johnson Space Center in Webster, Texas maintained the comet particles (it is also the home of most of the moon rocks recovered by the Apollo missions) and over 150 scientists from some of the most prestigious laboratories in the world helped with the analysis.
Among the tests they performed as confirmation of the results was an isotopic analysis. Isotopes of an element contain different numbers of neutrons than the most common version of that element, and the prevalence of different isotopes of a given element are well characterized. Using that information, scientists were able to confirm that the isotopic prevalence found in the glycine detected in the comet particles was not terrestrial contamination.
Where did the glycine come from, then? Theories abound, but the one with the greatest antiquity is the theory of panspermia (also known as exogenesis). First proposed in ancient Greece, many respected scientists since the Renaissance have expressed support for the idea that life came to Earth from outer space. This is one of the core areas of study in the field known as astrobiology, a multidisciplinary science that has existed formally since NASA established the first astrobiology program in 1960. Combining physics, astronomy, chemistry, biology and even more specialized sciences, astrobiology concerns itself with the study of the origin, evolution, distribution, and future of life in the universe.
The presence of even the simplest amino acid in the tail of a comet is a profound piece of evidence supporting the idea of panspermia. If this theory is correct, comets might well be the Johnny Appleseeds of the universe, slowly sowing their seeds of complex pre-biotic molecules throughout the galaxy – and suggesting that life on other worlds may be far more common than scientists once thought.
For more information:
NASA article on the discovery
http://www.nasa.gov/mission_pages/stardust/news/stardust_amino_acid.html
SCIENCE Magazine article on Wild-2 analysis (2006)
http://xray.physics.sunysb.edu/research/pdf_papers/2006/sandford_science_2006.pdf
More on the Wild-2 comet
http://en.wikipedia.org/wiki/Comet_Wild_2
More on Panspermia
http://en.wikipedia.org/wiki/Panspermia
More on Astrobiology:
http://en.wikipedia.org/wiki/Astrobiology
© AQOS / P. Smalley (2009)
Reproduction with attribution is appreciation
Are comets the disseminators of the seeds of life?
It was January 2, 2004. The NASA space probe known as Stardust passed through the tail of the Wild-2 comet, five years after the craft was launched on its mission to collect interstellar dust and particle samples from the tail, or coma, of the comet – particles that might well come from beyond Earth’s solar system. A specially-designed collector called an extra low density aerogel was used to capture the particles, and the probe’s camera took high-resolution images of the comet’s nucleus.
On January 15, 2006, the Stardust probe returned to Earth. A sonic boom and a fireball heralded its return over Utah’s Great Salt Lake desert. It was travelling at almost 29,000 miles per hour – the fastest re-entry speed into Earth's atmosphere ever achieved by a man-made object.
Since then, scientists in the Stardust Mission of NASA’s Jet Propulsion Laboratory have been hard at work analyzing the microscopic dust and particles it collected on its seven-year, three billion mile journey. And the results of that analysis are breathtaking.
Some things were expected. Silicate crystals had been predicted based on spectroscopic observations, but their presence confirmed not only those predictions but also the belief that the comet contained matter from outside the solar system.
Even more exciting, organic materials were detected. Astrobiologists have long been aware of aliphatic hydrocarbons (long chains of carbon and hydrogen) diffused throughout space, but the hydrocarbons found in the coma of Wild-2 were much longer than standard interstellar chains, indicating greater complexity. Methylamine and ethylamine, while simple molecules, were an exciting find as well because the nitrogen they contain is essential for life.
But on August 16, 2009, Dr. Jamie Elsila of NASA's Goddard Space Flight Center in Greenbelt, Maryland announced something astonishing. Scientists analyzing the Stardust samples had detected the presence of glycine, the simplest amino acid – and one of the critical building blocks of almost all life on Earth.
Rigorous testing was required in order to confirm this result. Every effort was made to ensure that "earth grime" did not contaminate the samples. The Johnson Space Center in Webster, Texas maintained the comet particles (it is also the home of most of the moon rocks recovered by the Apollo missions) and over 150 scientists from some of the most prestigious laboratories in the world helped with the analysis.
Among the tests they performed as confirmation of the results was an isotopic analysis. Isotopes of an element contain different numbers of neutrons than the most common version of that element, and the prevalence of different isotopes of a given element are well characterized. Using that information, scientists were able to confirm that the isotopic prevalence found in the glycine detected in the comet particles was not terrestrial contamination.
Where did the glycine come from, then? Theories abound, but the one with the greatest antiquity is the theory of panspermia (also known as exogenesis). First proposed in ancient Greece, many respected scientists since the Renaissance have expressed support for the idea that life came to Earth from outer space. This is one of the core areas of study in the field known as astrobiology, a multidisciplinary science that has existed formally since NASA established the first astrobiology program in 1960. Combining physics, astronomy, chemistry, biology and even more specialized sciences, astrobiology concerns itself with the study of the origin, evolution, distribution, and future of life in the universe.
The presence of even the simplest amino acid in the tail of a comet is a profound piece of evidence supporting the idea of panspermia. If this theory is correct, comets might well be the Johnny Appleseeds of the universe, slowly sowing their seeds of complex pre-biotic molecules throughout the galaxy – and suggesting that life on other worlds may be far more common than scientists once thought.
For more information:
NASA article on the discovery
http://www.nasa.gov/mission_pages/stardust/news/stardust_amino_acid.html
SCIENCE Magazine article on Wild-2 analysis (2006)
http://xray.physics.sunysb.edu/research/pdf_papers/2006/sandford_science_2006.pdf
More on the Wild-2 comet
http://en.wikipedia.org/wiki/Comet_Wild_2
More on Panspermia
http://en.wikipedia.org/wiki/Panspermia
More on Astrobiology:
http://en.wikipedia.org/wiki/Astrobiology
© AQOS / P. Smalley (2009)
Reproduction with attribution is appreciation
Friday, July 31, 2009
BS-o-meter: Detecting Pseudoscience
A QUANTUM OF SCIENCE
Pseudoscience is no joke.
While some of its claims may be laughable, countless otherwise intelligent people are taken in by claims of better health, extended life, or superior male equipment. Some of these "miracle cures" are harmless (except perhaps to your wallet) but others can be deadly – for instance, "energized water" made by adding the radioactive element radium! As consumers of not just materials but also of information, it is critical for everyone to be able to spot science scams when they come your way.
The single best piece of advice is simply this: Question. Be skeptical. Don’t believe everything you read, or take it at face value. Ask for references. Check the background. Read a book, or talk to an expert. Ask if someone is trying to make a buck – or a convert. And never forget that if it seems too good to be true, it probably is.
Common sense aside, here are some of the hallmarks of pseudoscience:
Use of vague, exaggerated or untestable claims. The language of science is that of objective, measurable quantities or verifiable characteristics. Good science also requires a narrow scope for its claims, and uses negative controls and blind tests to prevent it from reaching unjustified conclusions. Just what type of energy has been added to "energized water" anyway? Any claim that cannot be objectively measured or independently quantified is suggestive of pseudoscience.
Absence of authoritative references or citable sources. Scientists build on the work of those who came before them, and reference those sources extensively to show where their predecessors’ work ends and their own begins. By listing their sources, scientists establish their contribution in the context of previously tested and verified work in the same field, and present it for testing and verification by others. Any theory or claim lacking citations from established scientists in the same field should be viewed with extreme skepticism.
Unrepeatability or lack of openness to testing by other experts. The hallmark of science is reproducibility. If other scientists cannot replicate an experiment using the same conditions and materials described by the claimant, the claim is refuted. Pseudoscience often seeks evade this by making claims that are difficult or impossible to test and thus refute. Pseudoscience will sometimes make claims of "ancient knowledge" or "secret practices" from far-off lands, but these should be recognized as ways to convince the reader to be uncritical and accept the source’s claims without question.
Reductionism. In science, the simplest explanation is usually the correct one. This principle, known as Occam’s Razor, can be applied to any possible pseudoscientific claim as a way of discerning its value. If the explanation seems unduly complicated and unlikely, it is probably untrue.
Absence of progress. Science is constantly growing, learning, self-correcting and progressing. If a field does not constantly add to its body of knowledge, correct imperfections or errors in itself, or add further instances and explain further phenomena, chances are it is pseudoscience. For example, astrology today is almost identical to that of the last two millennia, and phrenology has not changed in the last 150 years since it first gained popularity.
Use of misleading language. Pseudoscience often seeks to cloak itself in the language of science and thus mislead the unsuspecting. This can be difficult for a non-scientist to detect or dispel, but overly-general terms such as "energy/energized" or overly-scientific terms such as "dihydrogen monoxide" (also know as H2O or water) are a sign of obfuscation and an attempt to mislead the reader. "Psi," "aura," "miracle," "natural" and "holistic" are other classic terms frequently misused in pseudoscientific claims.
Personalization of issues. Any theory that attracts extremists, the dogmatic, the charismatic, or that characterizes those who dispute it as enemies, is likely founded on pseudoscience. Often this is true of “scientific theories” propounded by extreme religious groups seeking to support a particular theology with something that sounds like science. Intelligent Design is one of the best examples of this – ultimately, this theory is not testable and thus cannot be the province of science, but rather of faith.
Claims of suppression, or of conspiracy to conceal or refute. Science is an open, peer-reviewed, transparent process – as it must be, in order to be cumulative and build upon itself. Real science is eagerly tested by others in the field, since it is either an innovation to be adopted or a fallacy to be exploded. It is only pseudoscience that shies away from peer review and independent testing. If a theory is supposedly being suppressed by the scientific establishment, it is likely to be in hiding from it instead.
Confirmation rather than refutation. In science, the burden of proof rests on those making a claim, not on the skeptic. Any theory that defies science to disprove it is likely to be pseudoscience.
Self-appointed experts and single-source theories. Successful scientific theories are tested by credentialed scientists and then used in their own work, leading to many examples and instances where it holds true. Often pseudoscience comes from someone lacking appropriate scientific credentials, or someone with unverifiable or obscure degrees from unlikely places. Also, if a theory is held only by a single person or a single group, and especially if that has been the case for an extended period of time, it is strongly suggestive of pseudoscience.
Association with financial gain. The adage ‘if it seems too good to be true, it probably is’ should be applied whenever claims of beneficial discoveries are purported. If a theory or claim is followed by an attempt to sell you a product or service purported to help you, especially in some subjective or non-quantifiable way, it is almost certainly pseudoscience and should be viewed with extreme skepticism.
For more information:
What is Pseudoscience?
H2O dot con: water-related pseudoscience, scams and quackery
Dowsing for Dollars – Fighting High-Tech Promises with Low-Tech Critical Thinking Skills
Crank dot net – a collection of scams and popular falsities on the web
© AQOS / P. Smalley (2009)
Reproduction with attribution is appreciation
Pseudoscience is no joke.
While some of its claims may be laughable, countless otherwise intelligent people are taken in by claims of better health, extended life, or superior male equipment. Some of these "miracle cures" are harmless (except perhaps to your wallet) but others can be deadly – for instance, "energized water" made by adding the radioactive element radium! As consumers of not just materials but also of information, it is critical for everyone to be able to spot science scams when they come your way.
The single best piece of advice is simply this: Question. Be skeptical. Don’t believe everything you read, or take it at face value. Ask for references. Check the background. Read a book, or talk to an expert. Ask if someone is trying to make a buck – or a convert. And never forget that if it seems too good to be true, it probably is.
Common sense aside, here are some of the hallmarks of pseudoscience:
Use of vague, exaggerated or untestable claims. The language of science is that of objective, measurable quantities or verifiable characteristics. Good science also requires a narrow scope for its claims, and uses negative controls and blind tests to prevent it from reaching unjustified conclusions. Just what type of energy has been added to "energized water" anyway? Any claim that cannot be objectively measured or independently quantified is suggestive of pseudoscience.
Absence of authoritative references or citable sources. Scientists build on the work of those who came before them, and reference those sources extensively to show where their predecessors’ work ends and their own begins. By listing their sources, scientists establish their contribution in the context of previously tested and verified work in the same field, and present it for testing and verification by others. Any theory or claim lacking citations from established scientists in the same field should be viewed with extreme skepticism.
Unrepeatability or lack of openness to testing by other experts. The hallmark of science is reproducibility. If other scientists cannot replicate an experiment using the same conditions and materials described by the claimant, the claim is refuted. Pseudoscience often seeks evade this by making claims that are difficult or impossible to test and thus refute. Pseudoscience will sometimes make claims of "ancient knowledge" or "secret practices" from far-off lands, but these should be recognized as ways to convince the reader to be uncritical and accept the source’s claims without question.
Reductionism. In science, the simplest explanation is usually the correct one. This principle, known as Occam’s Razor, can be applied to any possible pseudoscientific claim as a way of discerning its value. If the explanation seems unduly complicated and unlikely, it is probably untrue.
Absence of progress. Science is constantly growing, learning, self-correcting and progressing. If a field does not constantly add to its body of knowledge, correct imperfections or errors in itself, or add further instances and explain further phenomena, chances are it is pseudoscience. For example, astrology today is almost identical to that of the last two millennia, and phrenology has not changed in the last 150 years since it first gained popularity.
Use of misleading language. Pseudoscience often seeks to cloak itself in the language of science and thus mislead the unsuspecting. This can be difficult for a non-scientist to detect or dispel, but overly-general terms such as "energy/energized" or overly-scientific terms such as "dihydrogen monoxide" (also know as H2O or water) are a sign of obfuscation and an attempt to mislead the reader. "Psi," "aura," "miracle," "natural" and "holistic" are other classic terms frequently misused in pseudoscientific claims.
Personalization of issues. Any theory that attracts extremists, the dogmatic, the charismatic, or that characterizes those who dispute it as enemies, is likely founded on pseudoscience. Often this is true of “scientific theories” propounded by extreme religious groups seeking to support a particular theology with something that sounds like science. Intelligent Design is one of the best examples of this – ultimately, this theory is not testable and thus cannot be the province of science, but rather of faith.
Claims of suppression, or of conspiracy to conceal or refute. Science is an open, peer-reviewed, transparent process – as it must be, in order to be cumulative and build upon itself. Real science is eagerly tested by others in the field, since it is either an innovation to be adopted or a fallacy to be exploded. It is only pseudoscience that shies away from peer review and independent testing. If a theory is supposedly being suppressed by the scientific establishment, it is likely to be in hiding from it instead.
Confirmation rather than refutation. In science, the burden of proof rests on those making a claim, not on the skeptic. Any theory that defies science to disprove it is likely to be pseudoscience.
Self-appointed experts and single-source theories. Successful scientific theories are tested by credentialed scientists and then used in their own work, leading to many examples and instances where it holds true. Often pseudoscience comes from someone lacking appropriate scientific credentials, or someone with unverifiable or obscure degrees from unlikely places. Also, if a theory is held only by a single person or a single group, and especially if that has been the case for an extended period of time, it is strongly suggestive of pseudoscience.
Association with financial gain. The adage ‘if it seems too good to be true, it probably is’ should be applied whenever claims of beneficial discoveries are purported. If a theory or claim is followed by an attempt to sell you a product or service purported to help you, especially in some subjective or non-quantifiable way, it is almost certainly pseudoscience and should be viewed with extreme skepticism.
For more information:
What is Pseudoscience?
H2O dot con: water-related pseudoscience, scams and quackery
Dowsing for Dollars – Fighting High-Tech Promises with Low-Tech Critical Thinking Skills
Crank dot net – a collection of scams and popular falsities on the web
© AQOS / P. Smalley (2009)
Reproduction with attribution is appreciation
Monday, July 27, 2009
Telemedicine: Cell Phone Microscopy
A QUANTUM OF SCIENCE
Can technical innovations bring medical diagnostics anywhere a cell phone can go?
It is increasingly common for medical professionals to use images generated by light microscopy in the rapid evaluation and dissemination of a diagnosis of disease. This practice is so widespread that a medical communication standard has been adopted for using transferring digital images between doctors and institutions. This has resulted in improvements in rapid diagnosis of disease, but rural areas and developing nations lag far behind this due to the prohibitive cost of equipment and training required. Light microscopes and their more exotic cousins (dark-field, fluorescence microscopy, etc) are far from universal medical devices. Worse still for underserved regions, microscopy is an essential tool for diagnosis of diseases endemic to such areas. Tuberculosis, malaria and sickle-cell anemia are just a handful of the afflictions most easily characterized by microscopy, and which are also extremely common in developing nations.
What is strange and in this case fortunate is that rural areas and developing nations are being more quickly served by mobile phone providers, and thanks to this fact researchers in Berkeley, California were able to engineer a device that could interface with a standard cell phone to capture, analyze and transmit high-resolution microscopic images such that positive diagnoses could be made.
Using a Nokia phone equipped with only a 3.2-megapixel CMOS camera, scientists and engineers were able to construct a device consisting of two filters and three lenses that was capable of capturing high-quality microscopic images of blood (allowing positive diagnosis of malaria and sickle-cell anemia) and sputum (allowing positive diagnosis of tuberculosis). The latter required the addition of an LED emitting in the ultraviolet spectrum, permitting fluorescence microscopic images to be captured by the cell phone’s camera. While minimal image modification was required for the light microscopy images, even the fluorescence microscopy images needed only minor processing before they could be analyzed successfully.
The power and utility of this innovation of science and engineering cannot be easily overstated. For a relative pittance, the power of expensive and complex instruments requiring trained technicians to operate is now available to anyone with a cell phone. Soon, underserved rural areas and developing nations will have the possibility of rapid and high-accuracy diagnoses. With this piece of technical know-how the scientists, engineers and medical professionals of Berkeley have pushed back the darkness a little farther and paved the way for a better quality of life for many who suffer only because of where they happen to have been born.
For more information:
Mobile Phone Based Clinical Microscopy for Global Health Applications (Breslauer et al)
© AQOS / P. Smalley
Reproduction with attribution is appreciation
Can technical innovations bring medical diagnostics anywhere a cell phone can go?
It is increasingly common for medical professionals to use images generated by light microscopy in the rapid evaluation and dissemination of a diagnosis of disease. This practice is so widespread that a medical communication standard has been adopted for using transferring digital images between doctors and institutions. This has resulted in improvements in rapid diagnosis of disease, but rural areas and developing nations lag far behind this due to the prohibitive cost of equipment and training required. Light microscopes and their more exotic cousins (dark-field, fluorescence microscopy, etc) are far from universal medical devices. Worse still for underserved regions, microscopy is an essential tool for diagnosis of diseases endemic to such areas. Tuberculosis, malaria and sickle-cell anemia are just a handful of the afflictions most easily characterized by microscopy, and which are also extremely common in developing nations.
What is strange and in this case fortunate is that rural areas and developing nations are being more quickly served by mobile phone providers, and thanks to this fact researchers in Berkeley, California were able to engineer a device that could interface with a standard cell phone to capture, analyze and transmit high-resolution microscopic images such that positive diagnoses could be made.
Using a Nokia phone equipped with only a 3.2-megapixel CMOS camera, scientists and engineers were able to construct a device consisting of two filters and three lenses that was capable of capturing high-quality microscopic images of blood (allowing positive diagnosis of malaria and sickle-cell anemia) and sputum (allowing positive diagnosis of tuberculosis). The latter required the addition of an LED emitting in the ultraviolet spectrum, permitting fluorescence microscopic images to be captured by the cell phone’s camera. While minimal image modification was required for the light microscopy images, even the fluorescence microscopy images needed only minor processing before they could be analyzed successfully.
The power and utility of this innovation of science and engineering cannot be easily overstated. For a relative pittance, the power of expensive and complex instruments requiring trained technicians to operate is now available to anyone with a cell phone. Soon, underserved rural areas and developing nations will have the possibility of rapid and high-accuracy diagnoses. With this piece of technical know-how the scientists, engineers and medical professionals of Berkeley have pushed back the darkness a little farther and paved the way for a better quality of life for many who suffer only because of where they happen to have been born.
For more information:
Mobile Phone Based Clinical Microscopy for Global Health Applications (Breslauer et al)
© AQOS / P. Smalley
Reproduction with attribution is appreciation
Thursday, July 23, 2009
Biomining: Panning for Gold with Viruses
A QUANTUM OF SCIENCE
How can viruses solve an industrial mining problem?
One of the most abundant forms of life on earth is a humble virus called a bacteriophage. Phage for short, it exists only to infect bacteria; they are harmless to plants and animals. But scientists have long used phage as a way to search for special protein sequences with unique properties – in this case, the ability to selectively bind to specific metal ores.
An emerging technology, gold- and silver-binding phages were known in the literature but only as curiosities until a scientist at the University of British Columbia Institute of Mining Engineering wondered if he could find a phage that bound copper sulfide.
Industrial mining practices typically grind ore into a fine powder to aid in separating the ore of interest from other minerals. Special chemicals called flotation aids are added to this liquid slurry of various minerals and make the copper sulfide particles hydrophobic. These particles then adhere to bubbles in the slurry and float to the top, making a solid layer of the desired ore that can easily be extracted.
The problem comes in when very similar ores are present in the same slurry. To solve this problem, Dr. Scott Dunbar of UBC decided to search for a phage that selectively bound the mineral chalcopyrite (CuFeS2). In collaboration with scientists at the UBC’s Centre for Blood Research and the Department of Biochemistry and Molecular Biology, Dunbar found three unique phages that bound tightly and selectively to chalcopyrite, sphalerite (ZnS), or both. Using these selective phages, researchers were able to enrich ore slurries for the desired mineral ore, even in the presence of the other – in effect, panning for gold among the sand.
From this similarity the term biomining was coined.
Not only the mining industry may benefit from this advance. In addition to the reduction or elimination of flotation reagents from the industrial mining process (a potent source of environmentally unfriendly chemicals), this achievement demonstrates the potential for ore-binding phages as a powerful bioremediation technology. Heavy metals such as lead and cadmium could be more easily removed from contaminated soils using similar phages, and even some nuclear wastes might be amenable to biomining remediation. As an innovative technology, biomining has capabilities that are only just beginning to be imagined, let alone tapped.
For further information:
Virus may lend a hand in copper mining
Biomining with bacteriophage: Selectivity of displayed peptides for naturally occurring sphalerite and chalcopyrite (Curtis et al)
© A Quantum of Science / P. Smalley
Reproduction with attribution is appreciation
How can viruses solve an industrial mining problem?
One of the most abundant forms of life on earth is a humble virus called a bacteriophage. Phage for short, it exists only to infect bacteria; they are harmless to plants and animals. But scientists have long used phage as a way to search for special protein sequences with unique properties – in this case, the ability to selectively bind to specific metal ores.
An emerging technology, gold- and silver-binding phages were known in the literature but only as curiosities until a scientist at the University of British Columbia Institute of Mining Engineering wondered if he could find a phage that bound copper sulfide.
Industrial mining practices typically grind ore into a fine powder to aid in separating the ore of interest from other minerals. Special chemicals called flotation aids are added to this liquid slurry of various minerals and make the copper sulfide particles hydrophobic. These particles then adhere to bubbles in the slurry and float to the top, making a solid layer of the desired ore that can easily be extracted.
The problem comes in when very similar ores are present in the same slurry. To solve this problem, Dr. Scott Dunbar of UBC decided to search for a phage that selectively bound the mineral chalcopyrite (CuFeS2). In collaboration with scientists at the UBC’s Centre for Blood Research and the Department of Biochemistry and Molecular Biology, Dunbar found three unique phages that bound tightly and selectively to chalcopyrite, sphalerite (ZnS), or both. Using these selective phages, researchers were able to enrich ore slurries for the desired mineral ore, even in the presence of the other – in effect, panning for gold among the sand.
From this similarity the term biomining was coined.
Not only the mining industry may benefit from this advance. In addition to the reduction or elimination of flotation reagents from the industrial mining process (a potent source of environmentally unfriendly chemicals), this achievement demonstrates the potential for ore-binding phages as a powerful bioremediation technology. Heavy metals such as lead and cadmium could be more easily removed from contaminated soils using similar phages, and even some nuclear wastes might be amenable to biomining remediation. As an innovative technology, biomining has capabilities that are only just beginning to be imagined, let alone tapped.
For further information:
Virus may lend a hand in copper mining
Biomining with bacteriophage: Selectivity of displayed peptides for naturally occurring sphalerite and chalcopyrite (Curtis et al)
© A Quantum of Science / P. Smalley
Reproduction with attribution is appreciation
Tuesday, July 21, 2009
Quantum: Get Stung and Get Paid
A QUANTUM OF SCIENCE
Dr. Duffy wants to give you malaria.
Well, sort of.
Researchers at the Seattle Biomedical Research Institute have developed a weakened version of the malaria bug (Plasmodium falciparum) by deleting from its genome the genetic instructions that allow it to invade the liver and to reproduce. Now SBRI has been approved to conduct human trials using this "neutered" malaria, testing various drugs and vaccines for their effectiveness at blocking the parasite.
And volunteers will get paid somewhere between $2000 and $4000 for their trouble.
For more information:
Seattle Times article "You can get paid to catch malaria"
SBRI press release on the approval to conduct human trials with malaria vaccine
© A Quantum of Science / P. Smalley
Reproduction with attribution is appreciation
Dr. Duffy wants to give you malaria.
Well, sort of.
Researchers at the Seattle Biomedical Research Institute have developed a weakened version of the malaria bug (Plasmodium falciparum) by deleting from its genome the genetic instructions that allow it to invade the liver and to reproduce. Now SBRI has been approved to conduct human trials using this "neutered" malaria, testing various drugs and vaccines for their effectiveness at blocking the parasite.
And volunteers will get paid somewhere between $2000 and $4000 for their trouble.
For more information:
Seattle Times article "You can get paid to catch malaria"
SBRI press release on the approval to conduct human trials with malaria vaccine
© A Quantum of Science / P. Smalley
Reproduction with attribution is appreciation
Monday, July 20, 2009
Quantum: Less Antibiotique, merci
A QUANTUM OF SCIENCE
French government program educates about the danger of overuse of antibiotics
From 2002-2007 the French government has operated a program aimed at reducing the use of antibiotics for flu-like symptoms after a report came out showing that France used more antibiotics per capita than any other European nation. Called "Antibiotics are not Automatic" this program targeted overuse of antibiotics for flu-like symptoms, especially among the young. Now a report has been released showing the results of this program. Briefly, overall antibiotic use was down an average of 26% in all regions of the country and for all antibiotic categories (except quinolones). Remarkably, this reduction was even more pronounced among children (35%) and most of all in instances of those complaining of flu-like symptoms (45%). The important thing about this study is that broad health education can work on an entire population and over a reasonable period will result in major adjustment of behavior. Also worth noting is that the information used in the study was obtained through the online electronic database of French medical records, a system not unlike that which is being built by US government funding at present.
For more information:
Significant Reduction of Antibiotic Use in the Community after a Nationwide Campaign in France, 2002–2007 (Sabuncu et al)
© A Quantum of Science / P. Smalley
Reproduction with attribution is appreciation
French government program educates about the danger of overuse of antibiotics
From 2002-2007 the French government has operated a program aimed at reducing the use of antibiotics for flu-like symptoms after a report came out showing that France used more antibiotics per capita than any other European nation. Called "Antibiotics are not Automatic" this program targeted overuse of antibiotics for flu-like symptoms, especially among the young. Now a report has been released showing the results of this program. Briefly, overall antibiotic use was down an average of 26% in all regions of the country and for all antibiotic categories (except quinolones). Remarkably, this reduction was even more pronounced among children (35%) and most of all in instances of those complaining of flu-like symptoms (45%). The important thing about this study is that broad health education can work on an entire population and over a reasonable period will result in major adjustment of behavior. Also worth noting is that the information used in the study was obtained through the online electronic database of French medical records, a system not unlike that which is being built by US government funding at present.
For more information:
Significant Reduction of Antibiotic Use in the Community after a Nationwide Campaign in France, 2002–2007 (Sabuncu et al)
© A Quantum of Science / P. Smalley
Reproduction with attribution is appreciation
Tuesday, July 14, 2009
Quantum: Obesity fueled by reward-behavior gene
A QUANTUM OF SCIENCE
Obesity risk factor gene found to act in an unlikely place: our minds
Researchers analyzed the DNA of over 30,000 humans in 8 different studies and found three separate localed regions (or "loci") in their DNA where many of those studied had very similar subtle differences ("single-nucleotide polymorphisms"). The presence and number of copies of these genes with subtle differences correlated almost precisely with measurements of waist circumference, body mass index, and obesity. Two of these genes were known from other studies, but the newest gene, NRXN3, has a surprising role in the body. Instead of regulating the growth and proliferation of fat cells, or guiding the metabolic rate up or down, it acts on the central nervous system to modulate so-called "reward behavior," in which the brain receives positive feedback stimulation when a particular behavior is performed.
While these results are enlightening, they are not a genetic test for obesity risk nor even necessarily an indication that science is racing to "cure" obesity. But by understanding the underlying factors better, new strategies to address the expanding epidemic of obesity may be hastened. Moreover, NRXN3, is also associated with susceptibility to addiction and further research may reveal additional therapies to help affected individuals overcome that as well. What is more frightening is the knowledge of how similar those two scourges truly are - obesity as an addiction to food is a chilling idea.
For more information:
NRXN3 Is a Novel Locus for Waist Circumference: A Genome-Wide Association Study from the CHARGE Consortium (Nancy L. Heard-Costa et al)
© A Quantum of Science / P. Smalley
Reproduction with attribution is appreciation
Obesity risk factor gene found to act in an unlikely place: our minds
Researchers analyzed the DNA of over 30,000 humans in 8 different studies and found three separate localed regions (or "loci") in their DNA where many of those studied had very similar subtle differences ("single-nucleotide polymorphisms"). The presence and number of copies of these genes with subtle differences correlated almost precisely with measurements of waist circumference, body mass index, and obesity. Two of these genes were known from other studies, but the newest gene, NRXN3, has a surprising role in the body. Instead of regulating the growth and proliferation of fat cells, or guiding the metabolic rate up or down, it acts on the central nervous system to modulate so-called "reward behavior," in which the brain receives positive feedback stimulation when a particular behavior is performed.
While these results are enlightening, they are not a genetic test for obesity risk nor even necessarily an indication that science is racing to "cure" obesity. But by understanding the underlying factors better, new strategies to address the expanding epidemic of obesity may be hastened. Moreover, NRXN3, is also associated with susceptibility to addiction and further research may reveal additional therapies to help affected individuals overcome that as well. What is more frightening is the knowledge of how similar those two scourges truly are - obesity as an addiction to food is a chilling idea.
For more information:
NRXN3 Is a Novel Locus for Waist Circumference: A Genome-Wide Association Study from the CHARGE Consortium (Nancy L. Heard-Costa et al)
© A Quantum of Science / P. Smalley
Reproduction with attribution is appreciation
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