Monthly Archives: October 2012

Sweet medical implants courtesy of liquorice

Leave a reply

As you have guessed, they are not making implants out of liquorice. Instead, they are using a chemical found in liquorice plants to make nanocoatings that could protect the biological components of medical implants from sterilization procedures. The Oct. 8, 2012 news item on ScienceDaily provides more detail,

Publishing their findings in the latest issue of Materials Today, a team of researchers from Germany and Austria explain how conventional sterilization techniques based on a blast of radiation, or exposure to toxic gas can damage the functional biological components of the device. The coating, containing a component found in liquorice and developed by German biotech company LEUKOCARE AG, protects these sensitive components.

Joachim Koch of the Georg-Speyer Haus, Institute for Biomedical Research in Frankfurt am Main in Germany and colleagues explain how medical devices and implants are increasingly functionalized using pharmacologically active proteins, antibodies and other biomolecules. Harsh sterilization procedures, including beta and gamma irradiation or exposure to toxic ethylene oxide can damage these sensitive molecules and render the device useless. However, without sterilization the patient is at risk of infection when the device is used or implanted.

The team has now successfully evaluated the nano-coating; a technology which employs a composition of stabilizing nano-molecules. One important ingredient is a compound known as glycyrrhizic acid, a natural, sweet-tasting chemical found in liquorice. Unlike other stabilizing approaches used in biopharmaceutical formulations, the nano-coating contains no sugars, sugar-alcohol compounds or proteins that might otherwise interfere with the biological activity of the device.

I found out a little more about the liquorice plant from this essay in Wikipedia (Note: I have removed links and footnotes),

Liquorice or licorice …  is the root of Glycyrrhiza glabra from which a somewhat sweet flavor can be extracted. The liquorice plant is a legume (related to beans and peas) that is native to southern Europe and parts of Asia. It is not botanically related to anise, star anise, or fennel, which are the sources of similar flavouring compounds. The word ‘liquorice’/’licorice’ is derived (via the Old French licoresse), from the Greek γλυκύρριζα (glukurrhiza), meaning “sweet root”,from γλυκύς (glukus), “sweet” + ῥίζα (rhiza), “root”, the name provided by Dioscorides.

…

Liquorice extract is produced by boiling liquorice root and subsequently evaporating most of the water, and is traded both in solid and syrup form. Its active principle is glycyrrhizin [emphasis mine], a sweetener between 30 to 50 times as sweet as sucrose, and which also has pharmaceutical effects.

Here’s a botanical illustration,

Glycyrrhiza glabra Fabaceae
Original book source: Prof. Dr. Otto Wilhelm Thomé Flora von Deutschland,
Österreich und der Schweiz 1885, Gera, Germany Permission granted to use under GFDL by Kurt Stueber (downloaded from http://en.wikipedia.org/wiki/File:Illustration_Glycyrrhiza_glabra0.jpg)

This undated posting* on the Georg-Speyer-Haus Institute for Biomedical Research website  describes the testing process the team used,

The team has tested the nano-coating by coupling and stabilizing an anti-inflammatory antibody, which may be used in therapy, to a porous polyurethane surface. This carrier acts as a surrogate for a medical device. Such a system might be used as a therapeutic implant to reduce inflammation caused by an overactive immune system in severely ill patients. The researchers found that even if the test device is blasted with radiation to sterilize it entirely, neither the nano-coating nor the proteins are damaged by the radiation and the activity of the device is maintained. “This nano-coating formulation can now be applied for the production of improved biofunctionalized medical devices such as bone implants, vascular stents, and wound dressings and will ease the application of biomedical combination products,” Koch explains.

There’s no indication as to when this nanocoating will appear on the market. For those interested in the technical details, here’s the open access article, Nano-coating protects biofunctional materials by Rupert Tscheliessnig, Martin Zornig, Eva M. Herzig, Katharina Luckerath, Jens Altrichter, Kristina Kemter, Adnana Paunel-Gorgulu, Tim Logters, Joachim Windolf, Silvia Pabisch, Jindrich Cinatl, Holger F. Rabenau, Alois Jungbauer, Peter Muller-Buschbaum, Martin Scholz, and Joachim Koch can be found in Materials Today (2012) 15(9), 394-404.

LEUKOCARE AG, the company the company that developed the liquorice-based coating can be found here.

Revising the view on genomes: mouse and human

Leave a reply

Researchers in Canada and the US have resolved a question about DNA and structural protein. From the Oct. 4, 2012 news release on EurekAlert,

Scientists in Canada and the United States have used three-dimensional imaging techniques to settle a long-standing debate about how DNA and structural proteins are packaged into chromatin fibres. The researchers, whose findings are published in EMBO [European Molecular Biology Organization] reports, reveal that the mouse genome consists of 10-nm chromatin fibres but did not find evidence for the wider 30-nm fibres that were previously thought to be important components of the DNA architecture.

Scientists were trying to understand how DNA can be packed into a cell,

“DNA is an exceptionally long molecule that can reach several metres in length. This means it needs to be packaged into a highly compact state to fit within the limited space of the cell nucleus,” said David Bazett-Jones, Senior Scientist at the Hospital for Sick Children, Toronto, and Professor at the University of Toronto, Canada. “For the past few decades, scientists have favoured structural models for chromatin organization where DNA is first wrapped around proteins in nucleosomes. In one possible model, the strand of repeating nucleosomes is wrapped further into a higher-order thick 30-nm fibre. In a second model, the 30-nm fibre is not required to compact the DNA. Differences between these models have implications for the way the cell regulates the transcription of genes.”

Scientists offer reasons for why they concluded Previous studies have suggested for a 30-nm fibre model in earlier studies,

The researchers offer several reasons for the observation of wider fibres in earlier studies. In some cases, the conditions outside of the cell, including those used in earlier studies where chromatin was extracted from the cell, may have given rise to structural artifacts. For some of the earlier spectroscopic studies, it may even be a question of poor resolution of existing 10-nm fibres.

Here’s what the scientists found,

“Our results revealed that the 30-nm chromatin fibre model is not consistent with the structure we found in our three-dimensional spectroscopic images,” said Bazett-Jones. “It was previously thought that the transition between thinner and thicker fibres represented a change from an active to repressed state of chromatin. However, our inability to detect 30-nm fibres in the mouse genome leads us to conclude that the transcriptional machinery has widespread access to the DNA packaged into chromatin fibres.”

The results are consistent with recent studies of the human genome which suggest that approximately 80% of the genome contains elements that are linked to biological function. Access to enhancers, promoters and other regulatory sequences on such a wide region of the genome means that all of these sites must be accessible. The 10-nm model of chromatin fibres provides sufficient access to DNA to allow potential target sites to be reached. The 30-nm model would not accommodate such widespread access.

You can read more about the research both in the EurekAlert news release or in the Oct. 5, 2012 news itemon Azonano. Or, you can read the article, Open and closed domains in the mouse genome are configured as 10-nm chromatin fibres, if you can get behind the paywall.

More questions about whether nanoparticles penetrate the skin

Leave a reply

The research from the University of Bath about nanoparticles not penetrating the skin has drawn some interest. In addition to the mention here yesterday, in this Oct. 3, 2012 posting, there was this Oct. 2, 2012 posting by Dexter Johnson at the Nanoclast blog on the IEEE [Institute of Electrical and Electronics Engineers] website. I have excerpted the first and last paragraphs of Dexter’s posting as they neatly present the campaign to regulate the use of  nanoparticles in cosmetics and the means by which science progresses, i.e. this study is not definitive,

For at least the last several years, NGO’s like Friends of the Earth (FoE) have been leveraging preliminary studies that indicated that nanoparticles might pass right through our skin to call for a complete moratorium on the use of any nanomaterials in sunscreens and cosmetics.

…

This latest UK research certainly won’t put this issue to rest. These experiments will need to be repeated and the results duplicated. That’s how science works. We should not be jumping to any conclusions that this research proves nanoparticles are absolutely safe any more than we should be jumping to the conclusion that they are a risk. Science cuts both ways.

Meanwhile a writer in Australia, Sarah Berry, takes a different approach in her Oct. 4, 2012 article for the Australian newspaper, the  Sydney Morning Herald,

“Breakthrough” claims by cosmetic companies aren’t all they’re cracked up to be, according to a new study.

Nanotechnology — the science of super-small particles — has featured in cosmetic formulations since the late ’80s. Brands claim the technology delivers the “deep-penetrating action” of vitamins and other “active ingredients”.

You may think you know what direction Berry is going to pursue but she swerves,

Dr Gregory Crocetti, a nanotechnology campaigner with Friends of the Earth Australia, was scathing of the study. “To conclude that nanoparticles do not penetrate human skin based on a short-term study using excised pig skin is highly irresponsible,” he said. “This is yet another example of short-term, in-vitro research that doesn’t reflect real-life conditions like skin flexing, and the fact that penetration enhancers are used in most cosmetics. There is an urgent need for more long-term studies that actually reflect realistic conditions.”

Professor Brian Gulson, from Macquarie University in NSW, was was similarly critical. The geochemist’s own study, from 2010 and in conjunction with CSIRO [Australia’s national science agency, the Commonwealth Scientific and Industrial Research Organization], found that small amounts of zinc particles in sunscreen “can pass through the protective layers of skin exposed to the sun in a real-life environment and be detected in blood and urine”.

Of the latest study he said: “Even though they used a sophisticated method of laser scanning confocal microscopy, their results only reinforced earlier studies [and had] no relevance to ‘real life’, especially to cosmetics, because they used polystyrene nanoparticles, and because they used excised (that is, ‘dead’) pig’s skin.”

I missed the fact that this study was an in vitro test, which is always less convincing than in vivo testing. In my Nov. 29, 2011 posting about some research into nano zinc oxide I mentioned in vitro vs. in vivo testing and Brian Gulson’s research,

I was able to access the study and while I’m not an expert by any means I did note that the study was ‘in vitro’, in this case, the cells were on slides when they were being studied. It’s impossible to draw hard and fast conclusions about what will happen in a body (human or otherwise) since there are other systems at work which are not present on a slide.

…

… here’s what Brian Gulson had to say about nano zinc oxide concentrations in his work and about a shortcoming in his study (from an Australian Broadcasting Corporation [ABC] Feb. 25, 2010 interviewwith Ashley Hall,

BRIAN GULSON: I guess the critical thing was that we didn’t find large amounts of it getting through the skin. The sunscreens contain 18 to 20 per cent zinc oxide usually and ours was about 20 per zinc. So that’s an awful lot of zinc you’re putting on the skin but we found tiny amounts in the blood of that tracer that we used.

ASHLEY HALL: So is it a significant amount?

BRIAN GULSON: No, no it’s really not.

ASHLEY HALL: But Brian Gulson is warning people who use a lot of sunscreen over an extended period that they could be at risk of having elevated levels of zinc.

BRIAN GULSON: Maybe with young children where you’re applying it seven days a week, it could be an issue but I’m more than happy to continue applying it to my grandchildren.

ASHLEY HALL: This study doesn’t shed any light on the question of whether the nano-particles themselves played a part in the zinc absorption.

BRIAN GULSON: That was the most critical thing. This isotope technique cannot tell whether or not it’s a zinc oxide nano-particle that got through skin or whether it’s just zinc that was dissolved up in contact with the skin and then forms zinc ions or so-called soluble ions. So that’s one major deficiency of our study.

Of course, I have a question about Gulson’s conclusion  that very little of the nano zinc oxide was penetrating the skin based on blood and urine samples taken over the course of the study. Is it possible that after penetrating the skin it was stored in the cells  instead of being eliminated?

It seems it’s not yet time to press the panic button since more research is needed for scientists to refine their understanding of nano zinc oxide and possible health effects from its use.

What I found most interesting in Berry’s article was the advice from the Friends of the Earth,

The contradictory claims about sunscreen can make it hard to know what to do this summer. Friends of the Earth Australia advise people to continue to be sun safe — seeking shade, wearing protective clothing, a hat and sunglasses and using broad spectrum SPF 30+ sunscreen.

This is a huge change in tone for that organization, which until now has been relentless in its anti nanosunscreen stance. Here they advise using a sunscreen and they don’t qualify it as they would usually by saying you should avoid nanosunscreens. I guess after the debacle earlier this year (mentioned in this Feb. 9, 2012 posting titled: Unintended consequences: Australians not using sunscreens to avoid nanoparticles?), they have reconsidered the intensity of their campaign.

For anyone interested in some of the history of the Friends of the Earth’s campaign and the NGO (non governemental organization) which went against the prevailing sentiment against nanosunscreen, I suggest reading Dexter’s posting in full and for those interested in the response from Australian scientists about this latest research, do read Berry’s article.

Can nanoparticles pass through the skin or not?

2 Replies

Researchers at the University of Bath (England) have proved that nanoparticles do not penetrate the skin, according to the Oct. 1, 2012 news item on Nanowerk,

 Research by scientists at the University of Bath is challenging claims that nanoparticles in medicated and cosmetic creams are able to transport and deliver active ingredients deep inside the skin.
Nanoparticles, which are tiny particles that are less than one hundredth of the thickness of a human hair, are used in sunscreens and some cosmetic and pharmaceutical creams.
The Bath study (“Objective assessment of nanoparticle disposition in mammalian skin after topical exposure”) discovered that even the tiniest of nanoparticles did not penetrate the skin’s surface.
These findings have implications for pharmaceutical researchers and cosmetic companies that design skin creams with nanoparticles that are supposed to transport ingredients to the deeper layers of the skin. [emphasis mine]

Back in July 2012, a research team at Northwestern University claimed to have successfully delivered gene regulation technology using moisturizers to penetrate the skin barrier, excerpted from my July 4, 2012 posting,

The news item originated from a July 2, 2012 news release, by Marla Paul for Northwestern University, which provides more details about the researchers,

“The technology developed by my collaborator Chad Mirkin and his lab is incredibly exciting because it can break through the skin barrier,” said co-senior author Amy S. Paller, M.D., the Walter J. Hamlin Professor, chair of dermatology and professor of pediatrics at Northwestern University Feinberg School of Medicine. She also is director of Northwestern’s Skin Disease Research Center.

…

A co-senior author of the paper, Mirkin is the George B. Rathmann Professor of Chemistry in the Weinberg College of Arts and Sciences and professor of medicine, chemical and biological engineering, biomedical engineering and materials science and engineering. He also is the director of Northwestern’s International Institute for Nanotechnology.

…

Interdisciplinary research is a hallmark of Northwestern. Paller and Mirkin said their work highlights the power of physician-scientists and scientists and engineers from other fields coming together to address a difficult medical problem.

“This all happened because of our world-class presence in both cancer nanotechnology and skin disease research,” Paller said. “In putting together the Skin Disease Research Center proposal, I reached out to Chad to see if his nanostructures might be applied to skin disease. We initially worked together through a pilot project of the center, and now the rest is history.”

There’s more about how the nanoscale structures make their way through the skin but it seems the team from the University of Bath are prepared to contradict this claim, from the University of Bath’s Oct. 1,2012 news release (which originated the news item on Nanowerk),

Research by scientists at the University of Bath is challenging claims that nanoparticles in medicated and cosmetic creams are able to transport and deliver active ingredients deep inside the skin.

…

The Bath study discovered that even the tiniest of nanoparticles did not penetrate the skin’s surface.

These findings have implications for pharmaceutical researchers and cosmetic companies that design skin creams with nanoparticles that are supposed to transport ingredients to the deeper layers of the skin.

However the findings will also allay safety concerns that potentially harmful nanoparticles such as those used in sunscreens can be absorbed into the body.

The scientists used a technique called laser scanning confocal microscopy to examine whether fluorescently-tagged polystyrene beads, ranging in size from 20 to 200 nanometers, were absorbed into the skin. [emphasis mine]

They found that even when the skin sample had been partially compromised by stripping the outer layers with adhesive tape, the nanoparticles did not penetrate the skin’s outer layer, known as the stratum corneum.

I note they tested nanostructures larger than 20 nanometers so it’s possible that nanostructures that measure less than 20 nanometers could penetrate skin, non? However, it seems the structure used to ‘penetrate’ the skin by the team Northwestern University are considerably larger (excerpted from my July 4, 2012 posting),

The topical delivery of gene regulation technology to cells deep in the skin is extremely difficult because of the formidable defenses skin provides for the body. The Northwestern approach takes advantage of drugs consisting of novel spherical arrangements of nucleic acids. These structures, each about 1,000 times smaller than the diameter of a human hair, have the unique ability to recruit and bind to natural proteins that allow them to traverse the skin and enter cells.

(Side note: I believe a structure 1,000 times smaller than the diameter of a human hair would be measured in microns not nanometers.) I gather it’s the use of the nucleic acids in specialized formulations by the Northwestern team which make nanoparticle entry past the skin possible which contrasts with the work done by the University of Bath researchers who tested nanoparticles in standard cosmetic formulations.

Evelyn Fox Keller live in person in Halifax, Nova Scotia and on livestreaming video on Oct. 30, 2012

1 Reply

I got this announcement yesterday (Oct. 2, 2012),

The Situating Science Strategic Knowledge Cluster, funded by the Social Sciences and Humanities Research Council of Canada, and its partners are pleased to announce Dr. Evelyn Fox Keller as the Situating Science Visiting Scholar in Halifax Oct. 15th-Nov.7th. During her stay, Dr. Keller will participate in a series of public events (below), including a special public evening lecture on Tuesday, Oct. 30th.

PARADIGM SHIFTS AND REVOLUTIONS IN CONTEMPORARY BIOLOGY
Dr. Evelyn Fox Keller,
Professor Emerita of History and Philosophy of Science, Massachusetts Institute of Technology
TUESDAY, OCTOBER 30th, 7PM Atlantic Time [for those of us on the West Coast that means 3 PM]
Alumni Hall, New Academic Building at the University of King’s College,
6350 Coburg Road., Halifax, NS
“Join” our Situating Science Page Facebook event
http://www.facebook.com/events/386348911437524/

WATCH LIVE ONLINE

For event poster, live online viewing and latest information on all her activities, please visit our website: www.situsci.ca.

Fifty years ago, Thomas Kuhn irrevocably transformed our thinking about the sciences with the publication of The Structure of Scientific Revolutions. For all his success, debate about the adequacy and applicability of his formulation persists to this day. Are there scientific revolutions in biology? Molecular genetics, for example, is currently undergoing a major transformation in its understanding of what genes are and of what role they play in an organism’s development and evolution. Is this a revolution? More specifically, is this a revolution of the sort that Kuhn had in mind? How is language used? What implications can we draw from this?

Dr. Keller is the recipient of the prestigious MacArthur ‘Genius’ Award and author of many influential works on science, society and modern biology such as: A Feeling for the Organism: The Life and Work of Barbara McClintock (1983), Reflections on Gender and Science (1985), Secrets of Life, Secrets of Death: Essays on Language, Gender, and Science (1992), The Century of the Gene (2000), Making Sense of Life: Explaining Biological Development with Models, Metaphors and Machines (2002) and The Mirage of a Space Between Nature and Nurture (2010).

From Oct. 15th to Nov. 7th, Dr. Keller will conduct research on genomic plasticity and developmental stability. She will be housed jointly at the University of King’s College and the Department of Biology at Dalhousie University and will engage in various disciplinary and interdisciplinary sessions with students, faculty and the public. She will then continue on to Montreal and Toronto for other events. Please visit our website for more on those events.

THIS EVENT AND HALIFAX VISIT ARE GENEROUSLY SUPPORTED BY:
Situating Science Strategic Knowledge Cluster; Evolution Studies Group (funded with assistance from Canadian Institute for Advanced Research, CIFAR); Canadian Institutes of Health Research Institute of Genetics Community Support Program, Dalhousie University Department of Biology, Department of Philosophy and Health Law Institute; University of King’s College President’s Office, History of Science and Technology Programme, Contemporary Studies Programme, and Centre for Interdisciplinary Research; Nova Scotia Institute of Science; Saint Mary’s University Department of Philosophy and Faculty of Science;  Mount Saint-Vincent NSERC Atlantic Chair for Women in Science and Engineering, Dean of Arts, and Science and Institute for Women, Gender and Social Justice.

For anyone who would like to learn a little more about Evelyn Fox Keller, I’ve found two articles, one written by Andrew Brown for the UK Guardian, Nov. 4, 2000, and another written by Cornelia Dean for the New York Times, April 12, 2005.

ETA Oct. 29, 2012: Oops! I see the date for the livestreamed event was incorrect in my heading. It has now been corrected from Oct. 20, 2012 to Oct. 30, 2012.

Unforgeable credit card and qubits?

Leave a reply

The headline for the news item on Nanowerk and for the originating news release says ‘unforgeable’ but the researchers are being a little more cautious as I’m also seeing the words ‘almost impossible’ and ‘high probability’ in the text.

First, here’s a bit more about the researchers and their paper in an Oct. 2, 2012 news item on Nanowerk,

A team of physicists at Max-Planck-Institute of Quantum Optics (Garching [MPQ]), Harvard University (Cambridge, USA), and California Institute of Technology (Pasadena, USA) has demonstrated that such [noise-tolerant] protocols can be made tolerant to noise while ensuring rigorous security at the same time (“Unforgeable noise-tolerant quantum tokens”).

The researchers seem to be relying on a principle that perhaps we could call ‘imperfection’. The Max Planck Institute of Quantum Optics’ Oct. 2, 2012 news release, which originated the news item, provides some context,

Whoever has paid a hotel bill by credit card knows about the pending danger: given away the numbers of the card, the bank account and so on, an adversary might be able to forge a duplicate, take all the money from the account and ruin the person. On the other hand, as first acknowledged by Stephen Wiesner in 1983, nature provides ways to prevent forging: it is, for example, impossible to clone quantum information which is stored on a qubit. So why not use these features for the safe verification of quantum money? While the digits printed on a credit card are quite robust to the usual wear and tear of normal use in a wallet, its quantum information counterparts are generally quite challenged by noise, decoherence and operational imperfections. Therefore it is necessary to lower the requirements on the authentication process. A team of physicists at Max-Planck-Institute of Quantum Optics (Garching), Harvard University (Cambridge, USA), and California Institute of Technology (Pasadena, USA) has demonstrated that such protocols can be made tolerant to noise while ensuring rigorous security at the same time (Proceedings of the National Academy of Science (PNAS), 18 September, 2012 [article behind a paywall]).

The researchers illustrated their news release with this image,

Figure: Illustration of a quantum bill (IN QUANTUM PHYSICS WE TRUST)
© background by vektorportal.com, collage by F. Pastwaski

I have worked as a technical writer for telecommunications companies and in fact started with a data communications company that specialized in software for the financial services sector. Consequently, I feel reasonably comfortable about presenting this very brief overview of what happens when you (a legitimate user) put your credit/charge card or your bank/direct pay card (e.g. Interac) into a reader at a store or bank as a little background information before you read more about the ‘quantum credit card’.

  • All cards have bits of information on the magnetic strip which identify you and your financial institutions, e.g. your name, MasterCard, (issued by) Bank of Montreal
  • That data along with whatever amount you wish to charge or withdraw from your bank account is relayed from the reader through various pieces of hardware and software both to and from your financial institutions.
  • The hardware and software used in the transaction all operate according to protocols (rules for handling data). Difference pieces of hardware can and often do  have different protocols as do the different pieces of software.
    • For example, if your cards and institutions are based in Mexico and you’re in India trying to charge a purchase, your data is being sent through the network set up by the various financial institutions (hardware and software) in India then eventually bounced to Mexico (it may not be direct) via satellite and sent through the networks in Mexico onto your institutions (hardware and software) and then back again. That’s a lot  of hardware and software and while some of it may operate according to the same protocols, it’s reasonable to assume there’ will be a lot of changes and imperfections will creep in and this is the source of at least some of what the engineers call ‘noise’.

What I’ve just described (as accurately as I can recall) is the process for a legitimate user. These researchers are trying to find a means of foiling illegitimate users, which shifts the focus. Now, if I understand the information in the news release properly, the researchers have devised and tested two protocols for their unforgeable credit card (from the news release),

In both approaches, the bank issues a token and sends it to the holder. The “identity” of the token can be encoded on photons transmitted via an optical fibre or on nuclear spins in a solid memory transferred to the holder. However, only the bank stores a full classical description of these quantum states.

In the approach denoted by “quantum ticket”, the holder has to return the token to the bank or another trusted verifier for validation. The verifier is willing to tolerate a certain fraction of errors which should be enough to accommodate the imperfections associated with encoding, storage and decoding of individual quantum bits. The only information returned to the holder is whether the ticket has been accepted or rejected. Thus it is “consumed” and no longer available to the holder. The scientists show that through such an approach, both the likelihood of rejecting the token from an honest user and that of accepting a counterfeit can be made negligible.

The second approach is the “classical verification quantum ticket”. In some cases it may be impossible that the quantum tickets are given back to the bank physically. Here the holder has to validate his quantum token remotely – by answering challenge questions. The group considers a scheme where the quantum information is organized in blocks of qubit pairs. A non-revealing challenge question consists of requesting the holder to use a specific measurement basis for each block. By doing so, the holder is capable of providing a correct answer, but the token is consumed. This excludes the possibility for a dishonest user to cheat by answering complementary questions. As before, the given tolerance threshold determines the number of correct answers that is necessary for the verification of the token. The block structure used for the tokens allows exponentially suppressing the undesired capability of a dishonest holder to answer two complementary questions while assuring a true holder’s token will be authenticated with a very high probability.

For both protocols a realistic noise tolerance can be achieved.  “We can deduce from theory that on average no more than 83% of the secret digits may be duplicated correctly by a counterfeiter. Under realistic conditions, we can assume that an honest participant should be able to recover 95% of the digits. If now the verifier sets the tolerance level to 90%, it will be almost impossible [emphasis mine] to accept fraudulent tokens or to reject an authentic holder,” Dr. Pastawski [Dr. Fernando Pastawski (MPQ)] explains.

I think they’re proposing two different approaches rather than the simultaneous use of two different protocols.

I’ve highlighted ‘almost impossible’ in the text of the news release as it is not the same thing as ‘impossible’ which is implied by the word ‘unforgeable’. It’s been my observation that whenever crime fighter types think they’ve devised a criminal-proof solution, criminals make a point of subverting the new technology.  In any event, we’re a long way from seeing these ‘unforgeable’ credit cards, from the news release,

“I expect to live to see such applications become commercially available. However quantum memory technology still needs to mature for such protocols to become viable,” the scientist [Pastawski] adds.

Antikythera; ancient computer and a 100 year adventure

Leave a reply

This post has been almost two years in the making, which seems laughable when considering that the story starts in 100 BCE (before the common era).

Picture ancient Greece and a Roman sailing ship holding an object we know as an Antikythera, named after the Greek island near where the ship was wrecked and where it lay undiscovered until 1900. From the Dec.10, 2010 posting by GrrlScientist on the Guardian science blogs,

Two years ago [2008], a paper was published in Nature describing the function of the oldest known scientific computer, a device built in Greece around 100 BCE. Recovered in 1901 from a shipwreck near the island of Antikythera, this mechanism had been lost and unknown for 2000 years. It took one century for scientists to understand its purpose: it is an astronomical clock that determines the positions of celestial bodies with extraordinary precision. In 2010, a fully-functional replica was constructed out of Lego.

Here’s the video mentioned by Grrl Scientist,

As noted in the video, it is a replica that requires twice as many gears as the original to make the same calculations. It seems we still haven’t quite caught up with the past.

Bob Yirka’s April 4, 2011 article for phys.org describes some of the research involved in decoding the mechanism,

If modern research is correct, the device worked by hand cranking a main dial to display a chosen date, causing the wheels and gears inside to display (via tabs on separate dials) the position of the sun, moon, and the five known planets at that time, for that date; a mechanical and technical feat that would not be seen again until the fourteenth century in Europe with precision clocks.

…

Now James Evans and his colleagues at the University of Puget Sound in Washington State, have shown that instead of trying to use the same kind of gear mechanism to account for the elliptical path the Earth takes around the sun, and subsequent apparent changes in speed, the inventor of the device may have taken a different tack, and that was to stretch or distort the zodiac on the dial face to change the width of the spaces on the face to make up for the slightly different amount of time that is represented as the hand moves around the face.

In a paper published in the Journal for the History of Astronomy, Evans describes how he and his team were able to examine x-rays taken of the corroded machine (69 then later 88 degrees of the circle) and discovered that the two circles that were used to represent the Zodiac and Egyptian calendar respectively, did indeed differ just enough to account for what appeared to be the irregular movement during different parts of the year.

Though not all experts agree on the findings, this new evidence does appear to suggest that an attempt was made by the early inventor to take into account the elliptical nature of the Earth orbiting the sun, no small thing.

Jenny Winder’s June 11, 2012 article for Universe Today and republished on phys.org provides more details about the gears and the theories behind the device,

The device is made of bronze and contains 30 gears though it may have had as many as 72 originally. Each gear was meticulously hand cut with between 15 and 223 triangular teeth, which were the key to discovering the mechanism’s various functions. It was based on theories of astronomy and mathematics developed by Greek astronomers who may have drawn from earlier Babylonian astronomical theories and its construction could be attributed to the astronomer Hipparchus or, more likely, Archimedes the famous Greek mathematician, physicist, engineer, inventor and astronomer. … [emphases mine]

I’ve highlighted the verbs which suggest they’re still conjecturing as to where the theories and knowledge to develop this ancient computer came from. Yirka’s article mentions that some folks believe that the Antikythera may be the result of alien visitations, along with the more academic guesses about the Babylonians and the Greeks.

I strongly recommend reading the articles and chasing down more videos about the Antikythera on Youtube as the story is fascinating and given the plethora of material (including a book and website by Jo Marchant, Decoding the Heavens), I don’t seem to be alone in my fascination.

2012 Canadian Science Policy Conference and thinking big about Canadian science culture and policy

2 Replies

The 2012 Canadian Science Policy Conference is coming up in Calgary, Alberta on Nov. 5-7, 2012. and FrogHeart will be there moderating the Thinking Big: Science Culture and Policy in Canada panel. More about that in a minute but first, here’s the announcement, which I received at about  12:30 pm PDT, Oct. 1, 2012 (so this is pretty fresh off the email) :

Minister of State for Science and Technology, the Hon. Gary Goodyear, and Alberta Minister of Enterprise and Advanced Education, the Hon. Stephen Khan, will be speaking at the CSPC 2012

Calgary, Alberta November 5th – 7th

TORONTO, ONTARIO–(Marketwire – Sept. 28, 2012) – CSPC 2012 is pleased to announce that the Hon. Gary Goodyear, Minister of State for Science and Technology will provide the opening keynote address on Monday, November 5th at 8:45 AM.

Also, the Hon. Stephen Khan, Alberta Minister of Enterprise and Advanced Education will provide a luncheon keynote speech on Tuesday, November 6th.

CSPC 2012 will feature an impressive program with more than 90 speakers – leaders of science and innovation – from industry, academia, the media and government. These include:

  • Hon. Moira Stilwell,  MLA, Minister of Social Development, BC
  • Bob Fessenden, Premier’s Council for Economic Strategy, Government of Alberta
  • Dan Wicklum, CEO, Canada Oil Sands Innovation Alliance, (COSIA)
  • Antonia Maioni, Incoming President, Canadian Federation for the Humanities and Social Sciences
  • Jeffrey Simpson, National Affairs Columnist, The Globe and Mail
  • Jay Ingram, Founder, Beakerhead, Science Journalist
  • Rory McAlpine, Vice President, Maple Leaf Foods
  • Mike Herrington, Executive Director, Global Entrepreneurship Monitor (GEM)
  • Richard Hawkins, Canada Research Chair, Science, Technology and Innovation Policy, University of Calgary

Keynote session: Pulling Together: “What is the appropriate division of labour between business, government, and the academy in advancing science-based innovation in Canada?” a dialogue with the three Honourary Co-Chairs:

  • The Hon. Preston Manning C.C., President & CEO, Manning Centre for Building Democracy
  • Dr. Eric Newell, Chancellor Emeritus, University of Alberta, Former Chair and CEO, Syncrude Canada Ltd.
  • M. Elizabeth Cannon, PhD, FCAE, FRSC, President and Vice-Chancellor, University of Calgary

Twenty-one panel sessions, reflecting the four conference themes, submitted from across the country and internationally, including:

  • Innovation, R&D, and Productivity in the Oil and Gas Sector
  • Dissecting Canada’s Science & Technology Landscape
  • Innovation and Agriculture and the Role of Policy
  • Next Generation e-Health: Integrating Research, Policy, Industry
  • Entrepreneurship as a vehicle for innovation
  • “Science Policy 101” workshop

For the complete agenda please go to http://www.cspc2012.ca/glance.php and for descriptions of all the panel discussions see http://www.cspc2012.ca/paneldescriptions.php.

Don’t miss Canada’s premiere science policy conference as it brings a spotlight to Western Canada!

Follow us on Twitter @sciencepolicy, Facebook, and LinkedIn for the latest in science policy news and conference updates.

Register Now!

Register today at https://www.verney.ca/cspc2012/registration/index.php to benefit from the Early Bird rate (ends October 1, 2012).

The Canadian conference has a major fan in David Bruggeman of the Pasco Phronesis blog as per his Aug. 28, 2012 posting titled ‘Where Canada Might Lead The World – The Fourth Canadian Science Policy Conference‘,

Later this year the fourth Canadian Science Policy Conference (CSPC) will take place in Alberta, Calgary.  I attended the first conference in 2009, when it was held in Toronto.  I found it quite valuable, and not being Canadian, I think that says something.  In the three years since the first conference, the number of presenters and panels has grown consistently, and I think the conference provides an important convening function for the nation’s researchers and practitioners interested in science policy.

I wish we had something like it in the United States. …

As for the Thinking big panel, here’s the description,

Science culture is more than encouraging kids to become scientists to insure our economic future; more than having people visit a science museum or centre and having fun; more than reading an interesting article in a newspaper or magazine about the latest whizbang breakthrough; more than educating people so they become scientifically literate and encourage ‘good’ science policies; it is a comprehensive approach to community- and society-building.

We live in a grand (in English, magnificent and en francais, big) country, the 2nd largest in the world and it behooves us all to be engaged in developing a vibrant science culture which includes

  • artists (performing and visual),
  • writers,
  • scientists,
  • children,
  • seniors,
  • games developers,
  • doctors,
  • business people,
  • elected officials,
  • philosophers,
  • government bureaucrats,
  • educators,
  • social scientists,
  • and others

as we grapple with 21st century scientific and technical developments.

As scientists work on prosthetic neurons for repair in people with Parkinsons and other neurological diseases, techniques for tissue engineering, self-cleaning windows, exponentially increased tracking capabilities for devices and goods tagged with RFID devices, engineered bacteria that produce petroleum and other products (US Defense Advanced Research Projects Living Foundries project), and more, Canadians will be challenged to understand and adapt to a future that can be only dimly imagined.

Composed of provocative thinkers from the worlds of science writing, science education, art/science work, and scientific endeavour, during this panel discussion they will offer their ideas and visions for a Canadian science culture and invite you to share yours. In addition to answering questions, each panelist will prepare their own question for audience members to answer.

The panelists are:

Marie-Claire Shanahan

Marie-Claire Shanahan is a professor of science education and science communication at the University of Alberta. She is interested in how and why students make decisions to pursue their interests science, in high schools, post-secondary education and informal science education. She also conducts research on interactions between readers and writers in online science communications.

Stephen Strauss

Stephen Strauss, Canadian Science Writers’ Association president, has been writing about science for 30 years. After receiving a B.A. (history) from the University of Colorado, he worked as an English teacher, a social worker, an editor before joining the Globe and Mail in 1979. He began writing about science there.

Since leaving the newspaper in 2004 he has written for the CBC.ca, Nature, New Scientist, The Canadian Medical Association Journal as well as authored books and book chapters. He has written for organizations such as the Canada Foundation for Innovation and the Government of Ontario and has won numerous awards.

Amber Didow

Amber Didow is the Executive Director for the Canadian Association of Science Centres. She has over 20 years experience in the non-profit sector and advancing informal education. She has worked within the Science Centre field for many years including the Saskatchewan Science Centre and Science World British Columbia.  Amber’s background includes new business development; educational outreach; programming with at-risk youth; creating community based science events; melding science with art and overseeing the creation and development of both permanent and travelling exhibitions. Amber has a strong passion for community development within the sector.

Maryse de la Giroday (moderator)

Maryse de la Giroday currently runs one of the largest and longest running Canadian science blogs (frogheart.ca) where she writes commentary on  nanotechnology, science policy, science communication, society, and the arts. With a BA in Communication (Simon Fraser University, Canada) and an MA in Creative Writing and New Media (De Montfort University, UK), she combines education and training in the social sciences and humanities with her commitment as an informed member of the science public. An independent scholar, she has presented at international conferences on topics of nanotechnology, storytelling, and memristors.

Dr. Moira Stilwell, MLA

Dr. Moira Stilwell was appointed Minister of Social Development  for the province of British Columbia in September 2012. Elected MLA for Vancouver-Langara in the 2009 provincial general election. She previously served as Parliamentary Secretary for Industry, Research and Innovation to the Minister of Jobs, Tourism and Innovation and Parliamentary Secretary to the Minister of Health with a focus on Health Innovation. She also served as Vice Chair of the Cabinet Committee on Jobs and Economic Growth. In her first cabinet appointment, she served as Minister of Advanced Education and Labour Market Development from June 2009 to October 2010.

Prior to her political career, Stilwell graduated from the University of Calgary Medical School. She received further training in nuclear medicine at the University of British Columbia and in radiology at the University of Toronto after that. She served for several years as the Head of Nuclear Medicine at St. Paul’s Hospital, Vancouver, Surrey Memorial Hospital, and Abbotsford Regional Hospital and Cancer Clinic but left all those positions in 2009 to run for public office.

The driving force behind the province’s Year of Science in BC (2010-11) initiative for schools, Stilwell has a passionate interest and commitment to integrating science awareness and culture in government, education, and society.

Rob Annan

Rob is the Director of Policy, Research and Evaluation at Mitacs, a leading Canadian not-for-profit that supports innovation through skills development, research, and collaboration between students, researchers, and industry. Mitacs supports research across sciences, humanities and social sciences and understands that innovation often occurs at the intersection of science and culture. Mitacs’ approach to innovation is reflected in our outreach activities, most notably Math Out Loud – a theatre musical designed to inspire Canadian students to understand and appreciate the mathematics that surround them. Inspired by Laval University’s renowned Professor of Mathematics Jean-Marie De Koninck and produced by Academy Award winner Dale Hartleben, Math Out Loud explores the relationships between math and culture as an effective outreach tool.

Prior to joining Mitacs, Rob worked as a consultant to universities, researchers and non-profit agencies for strategic planning and policy, and was active as a blogger on science policy issues in Canada. Rob embodies the intersection of arts and science, with a PhD in Biochemistry from McGill University, a BSc in Biology from UVic and a BA in English from Queen’s University.

Hope to see you at the conference!

Graphene, replacing silicon, and epitaxial growth

Leave a reply

Researchers in Norway have created a semiconductor on a graphene substrate—absolutely no silicon in the substrate. From the Sept. 28, 2012 news item on Nanowerk,

Norwegian researchers are the world’s first to develop a method for producing semiconductors from graphene. This finding may revolutionise the technology industry.
The method involves growing semiconductor-nanowires on graphene. To achieve this, researchers “bomb” the graphene surface with gallium atoms and arsenic molecules, thereby creating a network of minute nanowires.
The result is a one-micrometre thick hybrid material which acts as a semiconductor. By comparison, the silicon semiconductors in use today are several hundred times thicker. The semiconductors’ ability to conduct electricity may be affected by temperature, light or the addition of other atoms.

The Research Council of Norway’s Sept.28, 2012 news release, which originated the news item, offers this,

Graphene is the thinnest material known, and at the same time one of the strongest. It consists of a single layer of carbon atoms and is both pliable and transparent. The material conducts electricity and heat very effectively. And perhaps most importantly, it is very inexpensive to produce.

“Given that it’s possible to make semiconductors out of graphene instead of silicon, we can make semiconductor components that are both cheaper and more effective than the ones currently on the market,” explains Helge Weman of the Norwegian University of Science and Technology (NTNU). Dr Weman is behind the breakthrough discovery along with Professor Bjørn-Ove Fimland.

“A material comprising a pliable base that is also transparent opens up a world of opportunities, one we have barely touched the surface of,” says Dr Weman. “This may bring about a revolution in the production of solar cells and LED components. Windows in traditional houses could double as solar panels or a TV screen. Mobile phone screens could be wrapped around the wrist like a watch. In short, the potential is tremendous.”

The researchers have patented this work and founded a startup company, CrayoNano. They provide a video animation of the process,

The narrator mentions epataxial growth and the gallium arsenide nanowires being grown on the graphene substrate. For anyone not familiar with ‘epataxial growth’, I found a definition in another Sept. 28, 2012 news item about graphene research on Nanowerk,

One of the best ways of producing high quality graphene is to grow it epitaxially (in layers) from crystals of silicon carbide. For use in electronic devices, it is important to be able to count the number of graphene layers that are grown, as single and double layers of graphene have different electrical properties.

This research out of the UK is based on using silicon as a substrate and you can find out more (excerpted from the  news item about the National Physical Laboratory’s graphene research on Nanowerk),

Recent National Physical Laboratory research, published in the Journal of Applied Physics (“Identification of epitaxial graphene domains and adsorbed species in ambient conditions using quantified topography measurements” [open access]), looked at different topography approaches of determining graphene thickness and investigated the factors that can influence the accuracy of the results, such as atmospheric water and other adsorbates on the graphene surface.

Getting back to graphene substrates, the Research Council of Norway’s news release provides the reminder that this research is about business,

The researchers will now begin to create prototypes directed towards specific areas of application. They have been in contact with giants in the electronics industry such as Samsung and IBM. “There is tremendous interest in producing semiconductors out of graphene, so it shouldn’t be difficult to find collaborative partners,” Dr Weman adds.

The researchers are hoping to have the new semiconductor hybrid materials on the commercial market in roughly five years.

Dexter Johnson in a Sept. 28, 2012 posting on his Nanoclast blog, which is hosted by the IEEE (Institute of Electrical and Electronics Engineers), provides some business perspective,

Weman notes: “Companies like IBM and Samsung are driving this development in the search for a replacement for silicon in electronics as well as for new applications, such as flexible touch screens for mobile phones. Well, they need not wait any more. Our invention fits perfectly with the production machinery they already have. We make it easy for them to upgrade consumer electronics to a level where design has no limits.”

As magnanimous as Weman’s invitation sounds, one can’t help but think it comes from concern. The prospect of a five-year-development period before a product gets to market might be somewhat worrying for a group of scientists who just launched a new startup. A nice licensing agreement from one of the big electronics companies must look appealing right about now.

Health science writing? Australian writer accuses gym equipment of killing you through nanotechnology

Leave a reply

Toby McCasker’s Sept. 30, 2012 article for news.com.au  is one of the more peculiar pieces I’ve seen about nanotechnology and its dangers. From the article,

Is gym equipment killing you?

THE nanofibres that make up sports and gym equipment just might be doing you more harm than good.

McCasker then blesses us with this wonderful, wonderful passage where he explains his concern,

Why is this (maybe) bad? Nanotechnology sounds awesome, after all. Very cyberpunk. Inject them into your dude piston and become a thrumming love-machine, all that. [emphases mine] They’re maybe bad because researchers from the University of Edinburgh in the UK have just discovered that some nanofibres bear a resemblance to asbestos fibres, which can cause lung cancer.

You can’t inject nanotechnology. Since it’s a field of study,  it would be the equivalent of injecting biology or quantum mechanics.

As for nanotechnology being cyberpunk, here’s how Cyberpunk is defined  in The Free Dictionary,

Noun   1.         cyberpunk – a programmer who breaks into computer systems in order to steal or change or destroy information as a form of cyber-terrorism

cyber-terrorist, hacker

act of terrorism, terrorism, terrorist act – the calculated use of violence (or the threat of violence) against civilians in order to attain goals that are political or religious or ideological in nature; this is done through intimidation or coercion or instilling fear

coder, computer programmer, programmer, software engineer – a person who designs and writes and tests computer programs

terrorist – a radical who employs terror as a political weapon; usually organizes with other terrorists in small cells; often uses religion as a cover for terrorist activities

2.         cyberpunk – a writer of science fiction set in a lawless subculture of an oppressive society dominated by computer technology

author, writer – writes (books or stories or articles or the like) professionally (for pay)

3.         cyberpunk – a genre of fast-paced science fiction involving oppressive futuristic computerized societies

science fiction – literary fantasy involving the imagined impact of science on society

The closest definition that fits McCasker’s usage is this description (the passage by Lawrence Person) of cyberpunk, a post-modern science fiction genre, in Wikipedia,

Cyberpunk plots often center on a conflict among hackers, artificial intelligences, and megacorporations, and tend to be set in a near-future Earth, rather than the far-future settings or galactic vistas found in novels such as Isaac Asimov’s Foundation or Frank Herbert’s Dune. The settings are usually post-industrial dystopias but tend to be marked by extraordinary cultural ferment and the use of technology in ways never anticipated by its creators (“the street finds its own uses for things”). Much of the genre’s atmosphere echoes film noir, and written works in the genre often use techniques from detective fiction.

“Classic cyberpunk characters were marginalized, alienated loners who lived on the edge of society in generally dystopic futures where daily life was impacted by rapid technological change, an ubiquitous datasphere of computerized information, and invasive modification of the human body.” – Lawrence Person

It’s the part about “invasive modification of the human body” which seems closest to McCasker’s ” inject them into your dude piston”  (dude piston is my new favourite phrase).

As for the reference to nanofibres, McCasker is correct. There are carbon nanotubes that resemble asbestos fibres and there is concern for anyone who may ingest them. As far as I know, the people at greatest risk would be workers who are exposed to the carbon nanotubes directly. I have not heard of anyone getting sick because of their golf clubs where carbon nanotubes are often used to make them lighter and stronger.

The research (mentioned in my Aug. 22, 2012 posting)  at the University of Edinburgh that McCasker cites is important because it adds to a body of substantive research work on this issue regarding carbon nanotubes, asbestos, and the possibility of mesothelioma and bears no mention of gym equipment.