Study shows medical marijuana laws reduce traffic deaths

Leads to lower consumption of alcohol

DENVER (Nov. 29, 2011) – A groundbreaking new study shows that laws legalizing medical marijuana have resulted in a nearly nine percent drop in traffic deaths and a five percent reduction in beer sales.

"Our research suggests that the legalization of medical marijuana reduces traffic fatalities through reducing alcohol consumption by young adults," said Daniel Rees, professor of economics at the University of Colorado Denver who co-authored the study with D. Mark Anderson, assistant professor of economics at Montana State University.

The researchers collected data from a variety of sources including the National Survey on Drug Use and Health, the Behavioral Risk Factor Surveillance System, and the Fatality Analysis Reporting System.

The study is the first to examine the relationship between the legalization of medical marijuana and traffic deaths.

"We were astounded by how little is known about the effects of legalizing medical marijuana," Rees said. "We looked into traffic fatalities because there is good data, and the data allow us to test whether alcohol was a factor."

Anderson noted that traffic deaths are significant from a policy standpoint.

"Traffic fatalities are an important outcome from a policy perspective because they represent the leading cause of death among Americans ages five to 34," he said.

The economists analyzed traffic fatalities nationwide, including the 13 states that legalized medical marijuana between 1990 and 2009. In those states, they found evidence that alcohol consumption by 20- through 29-year-olds went down, resulting in fewer deaths on the road.

The economists noted that simulator studies conducted by previous researchers suggest that drivers under the influence of alcohol tend to underestimate how badly their skills are impaired. They drive faster and take more risks. In contrast, these studies show that drivers under the influence of marijuana tend to avoid risks. However, Rees and Anderson cautioned that legalization of medical marijuana may result in fewer traffic deaths because it's typically used in private, while alcohol is often consumed at bars and restaurants.

"I think this is a very timely study given all the medical marijuana laws being passed or under consideration," Anderson said. "These policies have not been research-based thus far and our research shows some of the social effects of these laws. Our results suggest a direct link between marijuana and alcohol consumption."

The study also examined marijuana use in three states that legalized medical marijuana in the mid-2000s, Montana, Rhode Island, and Vermont. Marijuana use by adults increased after legalization in Montana and Rhode Island, but not in Vermont. There was no evidence that marijuana use by minors increased.

Opponents of medical marijuana believe that legalization leads to increased use of marijuana by minors.

According to Rees and Anderson, the majority of registered medical marijuana patients in Arizona and Colorado are male. In Arizona, 75 percent of registered patients are male; in Colorado, 68 percent are male. Many are under the age of 40. For instance, 48 percent of registered patients in Montana are under 40.

"Although we make no policy recommendations, it certainly appears as though medical marijuana laws are making our highways safer," Rees said.

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The study is entitled, "Medical Marijuana Laws, Traffic Fatalities, and Alcohol Consumption." It can be found at:http://www.iza.org/en/webcontent/personnel/photos/index_html?key=4915

Source: Eureka Alert!

A revolution in knot theory

Providence, RI--- In the 19th century, Lord Kelvin made the inspired guess that elements are knots in the "ether". Hydrogen would be one kind of knot, oxygen a different kind of knot---and so forth throughout the periodic table of elements. This idea led Peter Guthrie Tait to prepare meticulous and quite beautiful tables of knots, in an effort to elucidate when two knots are truly different. From the point of view of physics, Kelvin and Tait were on the wrong track: the atomic viewpoint soon made the theory of ether obsolete. But from the mathematical viewpoint, a gold mine had been discovered: The branch of mathematics now known as "knot theory" has been burgeoning ever since.

This knot has Gauss code O1U2O3U1O2U3.

In his article "The Combinatorial Revolution in Knot Theory", to appear in the December 2011 issue of the Notices of the AMS,, Sam Nelson describes a novel approach to knot theory that has gained currency in the past several years and the mysterious new knot-like objects discovered in the process.

As sailors have long known, many different kinds of knots are possible; in fact, the variety is infinite. A *mathematical* knot can be imagined as a knotted circle: Think of a pretzel, which is a knotted circle of dough, or a rubber band, which is the "un-knot" because it is not knotted. Mathematicians study the patterns, symmetries, and asymmetries in knots and develop methods for distinguishing when two knots are truly different.

Mathematically, one thinks of the string out of which a knot is formed as being a one-dimensional object, and the knot itself lives in three-dimensional space. Drawings of knots, like the ones done by Tait, are projections of the knot onto a two-dimensional plane. In such drawings, it is customary to draw over-and-under crossings of the string as broken and unbroken lines. If three or more strands of the knot are on top of each other at single point, we can move the strands slightly without changing the knot so that every point on the plane sits below at most two strands of the knot. A planar knot diagram is a picture of a knot, drawn in a two-dimensional plane, in which every point of the diagram represents at most two points in the knot. Planar knot diagrams have long been used in mathematics as a way to represent and study knots.

As Nelson reports in his article, mathematicians have devised various ways to represent the information contained in knot diagrams. One example is the Gauss code, which is a sequence of letters and numbers wherein each crossing in the knot is assigned a number and the letter O or U, depending on whether the crossing goes over or under. The Gauss code for a simple knot might look like this: O1U2O3U1O2U3.

In the mid-1990s, mathematicians discovered something strange. There are Gauss codes for which it is impossible to draw planar knot diagrams but which nevertheless behave like knots in certain ways. In particular, those codes, which Nelson calls *nonplanar Gauss codes*, work perfectly well in certain formulas that are used to investigate properties of knots. Nelson writes: "A planar Gauss code always describes a [knot] in three-space; what kind of thing could a nonplanar Gauss code be describing?" As it turns out, there are "virtual knots" that have legitimate Gauss codes but do not correspond to knots in three-dimensional space. These virtual knots can be investigated by applying combinatorial techniques to knot diagrams.

Just as new horizons opened when people dared to consider what would happen if -1 had a square root---and thereby discovered complex numbers, which have since been thoroughly explored by mathematicians and have become ubiquitous in physics and engineering---mathematicians are finding that the equations they used to investigate regular knots give rise to a whole universe of "generalized knots" that have their own peculiar qualities. Although they seem esoteric at first, these generalized knots turn out to have interpretations as familiar objects in mathematics. "Moreover," Nelson writes, "classical knot theory emerges as a special case of the new generalized knot theory."

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Related to this subject are an upcoming issue of the Journal of Knot Theory and its Ramifications, devoted to virtual knot theory, and the upcoming Knots in Washington conference at George Washington University, December 2-4, 2011, which will focus on on "Categorification of Knots, Algebras, and Quandles; Quantum Computing".

Courtesy of Eureka Alert!

Is sustainability science really a science? Los Alamos and Indiana University researchers say yes.

LOS ALAMOS, New Mexico, November 22, 2011—The idea that one can create a field of science out of thin air, just because of societal and policy need, is a bold concept.  But for the emerging field of sustainability science, sorting among theoretical and applied scientific disciplines, making sense of potentially divergent theory, practice and policy, the gamble has paid off.

In the current issue of theProceedings of the National Academy of Sciences, scientists from Los Alamos National Laboratory, Santa Fe Institute, and Indiana University analyzed the field’s temporal evolution, geographic distribution, disciplinary composition, and collaboration structure.

"We don’t know if sustainability science will solve the essential problems it seeks to address, but there is a legitimate scientific practice in place now," said Luís Bettencourt of Los Alamos National Laboratory and Santa Fe Institute, first author on the paper, "Evolution and structure of sustainability science.

The team’s work shows that although sustainability science has been growing explosively since the late 1980s, only in the last decade has the field matured into a cohesive area of science. Thanks to the emergence of a giant component of scientific collaboration spanning the globe and an array of diverse traditional disciplines, there is now an integrated scientific field of sustainability science as an unusual, inclusive, and ubiquitous scientific practice.

The researchers used an exhaustive literature search to determine if the field can truly be categorized as a legitimate science, using population modeling and documenting technical papers’ evolution over time, worldwide author distribution, range of sciences involved, and the collaboration structure of the participants. Many of these techniques form the basis of a new science of science, which allows researchers to analyze and predict the development of scientific and technological fields.

The researchers ask, “How has it been changing, and who are its contributors in terms of geographic and disciplinary composition? Most important, is the field fulfilling its ambitious program of generating a new synthesis of social, biological, and applied disciplines, and is it spanning locations that have both the capabilities and needs for its insights?”

Bettencourt said that they concluded that the field is both applied and basic, spanning worldwide institutions, governments, and corporations, but the key is the collaboration network that evolved in about the year 2000. “This has never been done, starting a worldwide scientific field defined mainly by the need for informed global social practice and policy,” Bettencourt said, “but sustainability science shows that it can be done.”

• Interactive graphic available: Global collaboration network of sustainability science. The maps show number of authors in cities worldwide (red columns) and their coauthorship networks (green lines). Thicker lines indicate a greater number of collaborations between places. The interactive Google Earth map is available athttp://www.santafe.edu/~bettencourt/sustainability/.
• Authors: Luís M. A. Bettencourt, Santa Fe Institute and Los Alamos National Laboratory Theoretical Division; and Jasleen Kaur, Center for Complex Networks and Systems Research, School of Informatics and Computing, Indiana University, Bloomington, Indiana.

About Los Alamos National Laboratory

Los Alamos National Laboratory, a multidisciplinary research institution engaged in strategic science on behalf of national security, is operated by Los Alamos National Security, LLC, a team composed of Bechtel National, the University of California, The Babcock & Wilcox Company, and URS for the Department of Energy's National Nuclear Security Administration.

Los Alamos enhances national security by ensuring the safety and reliability of the U.S. nuclear stockpile, developing technologies to reduce threats from weapons of mass destruction, and solving problems related to energy, environment, infrastructure, health, and global security concerns.

LANL news media contacts: Nancy Ambrosiano, (505) 667-0471, nwa@lanl.gov

Curtesy of

Los Alamos National Laboratory NEWS CENTER

Molecules to Medicine: Should pepper spray be put on (clinical) trial?

Pepper spray is all over the news, following the Occupy Wall Street protests, particularly following the widely disseminated images and videos of protestors being sprayed in NY, Portland, andUCDavis.
Before that, I knew and occasionally used its main ingredient, capsaicin, as a treatment for my patients with shingles, an extremely painful Herpes zoster infection. And I knew about the many of the serious side effects of pepper spray, well-described by Deborah Blum.
Recently though, other questions arose, like “How was this learned?”. So off I went, looking for clinical trials to see what, if anything, had been studied, beyond the individual patient, poison control, and toxicology reports. Here’s what I learned:

There are reports of the efficacy of capsaicin in crowd control, but little regarding trials of exposures. Perhaps this is because pepper spray is regulated by the Environmental Protection Agency, as a pesticide and not by the FDA.

The concentration of capsaicin in bear spray is 1-2%; it is 10-30% in “personal defense sprays.”

While the police might feel reassured by the study, “The effect of oleoresin capsicum “pepper” spray inhalation on respiratory function,” I was not. This study met the “gold standard” of clinical trials, in that it was a “randomized, cross-over controlled trial to assess the effect of Oleoresin capsicum (OC) spray inhalation on respiratory function by itself and combined with restraint.” However, while the OC exposure showed no ill effect, only 34 volunteers were exposed to only 1 sec of Cap-Stun 5.5%OC spray by inhalation “from 5 ft away as they might in the field setting (as recommended by both manufacturer and local police policies).”

By contrast, an ACLU report, “Pepper Spray Update: More Fatalities, More Questions” found, in just two years, 26 deaths after OC spraying, noting that death was more likely if the victim was also restrained. This translated to 1 death per 600 times police used spray. (The cause of death was not firmly linked to the OC). According to the ACLU, “an internal memorandum produced by the largest supplier of pepper spray to the California police and civilian markets” concludes that there may be serious risks with more than a 1 sec spray. A subsequent Department of Justice study examined another 63 deaths after pepper spray during arrests; the spray was felt to be a “contributing factor” in several.

A review in 1996 by the Division of Epidemiology of the NC DHHS and OSHA concluded that exposure to OC spray during police training constituted an unacceptable health risk.

Surveillance into crowd control agents examined reports to the British National Poisons Information Service, finding more late (>6 hour) adverse events than had been previously noted, especially skin reactions (blistering, rashes).

Studies have, understandably, more looked at treatment than at systematically exploring toxic effects of pepper spray. An uncontrolled California Poison Control study of 64 patients with exposure to capsaicin (as spray or topically as a cream) showed benefit with topically applied antacids, especially if applied soon after exposure.

In a randomized clinical trial, 47 subjects were assigned to a placebo, a topical nonsteroidal anti-inflammatory agent, or a topical anesthetic. The only group with significant symptomatic improvement in pain received proparacaine hydrochloride 0.5%–and only 55% had decreased pain with treatment.

Another randomized controlled trial looked at 49 volunteers who were treated with one of five treatment groups(aluminum hydroxide–magnesium hydroxide [Maalox], 2% lidocaine gel, baby shampoo, milk, or water). There was a significant difference in pain with more rapid treatment, but not between the groups.

I was most impressed with the efforts of the Black Cross Health Collective in Portland, Oregon. These activists have been thoughtfully approaching studying treatments for pepper spray exposures with published clinical trial protocols, where each volunteer also serves as their own control. Capsaicin is applied to each arm; a “subject-blinded” treatment is applied to one arm, and differences in pain responses are recorded. I love that they are looking for evidenced based solutions.

So far, antacids have been the most effective.

Suggestions for further study

Pepper spray causes inflammation and swelling—particularly a danger for those with underlying asthma or emphysema. In fact, the Department of Justice report notes that in two of 63 clearly documented deaths, the subjects were asthmatic. If they don’t already, police need to have protocols in place to identify and treat “sprayees” who have these pre-existing conditions that predispose them to serious harm from the spray. This particularly holds true for people also at risk for respiratory compromise from being restrained, on other drugs, or with obesity. The study of restrained healthy volunteers exposed to small amounts of capsaicin is simply not applicable to the general population. Also, given that these compounds appear to have delayed effects, there should be legally required medical monitoring of “sprayees” at regular and frequent intervals for at least 24 hours—by someone competent. (Iraq war veteran Kayvan Sabehgi could easily have died from the lacerated spleen sustained in his beating by police. It was 18 hours before he was taken to the hospital, after the jail’s nurse reportedly only offered him a suppository for his abdominal pain. There is also an, as yet unconfirmed report, of a miscarriage after the Portland, Oregon OWS protest last week).

Unfortunately, there is an urgent need for clinical trials in this area—both retrospective assessments of “sprayees” health outcomes, and prospective randomized trials [like the trial done on subjects' arms] to elucidate the effects of various capsaicin concentrations, carrier solvents and propellents and to identify the most effective treatments for each mixture. Until those can be done, there should be a thorough outcomes registry kept, with standardized data being obtained on all those subsequent to being pepper-sprayed.

Sadly, I’m sure the Black Cross and others in the Occupy Wall Street movement will have too many opportunities to test therapies against painful crowd-control chemicals. Studies will be difficult because the settings are largely uncontrolled and because the sprays have different concentrations of capsaicin, carrier solvents, and propellants.

Until then, there should be a moratorium on the use of pepper spray or other “non-lethal” chemicals by police, except in clearly life-threatening confrontations, due to the high number of associated deaths until the risks are better understood?

Perhaps Kamran Loghman, who helped the FBI weaponize pepper spray, will be dismayed enough at the “inappropriate and improper use of chemical agents” to help the Black Cross develop effective antidotes…One can only hope.

Courtesy of Scientific American guest blogger Judy Stone

EVERYTHING FROM NOTHING - the empty set axiom and construction of numbers in mathematics

THE mathematicians' version of nothing is the empty set. This is a collection that doesn't actually contain anything, such as my own collection of vintage Rolls-Royces. The empty set may seem a bit feeble, but appearances deceive; it provides a vital building block for the whole of mathematics.

Click on image to enlarge

It all started in the late 1800s. While most mathematicians were busy adding a nice piece of furniture, a new room, even an entire storey to the growing mathematical edifice, a group of worrywarts started to fret about the cellar. Innovations like non-Euclidean geometry and Fourier analysis were all very well - but were the underpinnings sound? To prove they were, a basic idea needed sorting out that no one really understood. Numbers.

Sure, everyone knew how to do sums. Using numbers wasn't the problem. The big question was what they were. You can show someone two sheep, two coins, two albatrosses, two galaxies. But can you show them two?

The symbol "2"? That's a notation, not the number itself. Many cultures use a different symbol. The word "two"? No, for the same reason: in other languages it might be deux or zwei or futatsu. For thousands of years humans had been using numbers to great effect; suddenly a few deep thinkers realised no one had a clue what they were.

An answer emerged from two different lines of thought: mathematical logic, and Fourier analysis, in which a complex waveform describing a function is represented as a combination of simple sine waves. These two areas converged on one idea. Sets.

A set is a collection of mathematical objects - numbers, shapes, functions, networks, whatever. It is defined by listing or characterising its members. "The set with members 2, 4, 6, 8" and "the set of even integers between 1 and 9" both define the same set, which can be written as {2, 4, 6, 8}.

Around 1880 the mathematician Georg Cantor developed an extensive theory of sets. He had been trying to sort out some technical issues in Fourier analysis related to discontinuities - places where the waveform makes sudden jumps. His answer involved the structure of the set of discontinuities. It wasn't the individual discontinuities that mattered, it was the whole class of discontinuities.

How many dwarfs?

One thing led to another. Cantor devised a way to count how many members a set has, by matching it in a one-to-one fashion with a standard set. Suppose, for example, the set is {Doc, Grumpy, Happy, Sleepy, Bashful, Sneezy, Dopey}. To count them we chant "1, 2, 3..." while working along the list: Doc (1), Grumpy (2), Happy (3), Sleepy (4), Bashful (5), Sneezy (6) Dopey (7). Right: seven dwarfs. We can do the same with the days of the week: Monday (1), Tuesday (2), Wednesday (3), Thursday (4), Friday (5), Saturday (6), Sunday (7).

Another mathematician of the time, Gottlob Frege, picked up on Cantor's ideas and thought they could solve the big philosophical problem of numbers. The way to define them, he believed, was through the process of deceptively simple process of counting.

What do we count? A collection of things - a set. How do we count it? By matching the things in the set with a standard set of known size. The next step was simple but devastating: throw away the numbers. You could use the dwarfs to count the days of the week. Just set up the correspondence: Monday (Doc), Tuesday (Grumpy)... Sunday (Dopey). There are Dopey days in the week. It's a perfectly reasonable alternative number system. It doesn't (yet) tell us what a number is, but it gives a way to define "same number". The number of days equals the number of dwarfs, not because both are seven, but because you can match days to dwarfs.

What, then, is a number? Mathematical logicians realised that to define the number 2, you need to construct a standard set which intuitively has two members. To define 3, use a standard set with three numbers, and so on. But which standard sets to use? They have to be unique, and their structure should correspond to the process of counting. This was where the empty set came in and solved the whole thing by itself.

Zero is a number, the basis of our entire number system (see "Zero's convoluted history"). So it ought to count the members of a set. Which set? Well, it has to be a set with no members. These aren't hard to think of: "the set of all honest bankers", perhaps, or "the set of all mice weighing 20 tonnes". There is also a mathematical set with no members: the empty set. It is unique, because all empty sets have exactly the same members: none. Its symbol, introduced in 1939 by a group of mathematicians that went by the pseudonym Nicolas Bourbaki, is ?. Set theory needs ? for the same reason that arithmetic needs 0: things are a lot simpler if you include it. In fact, we can define the number 0 as the empty set.

What about the number 1? Intuitively, we need a set with exactly one member. Something unique. Well, the empty set is unique. So we define 1 to be the set whose only member is the empty set: in symbols, {?}. This is not the same as the empty set, because it has one member, whereas the empty set has none. Agreed, that member happens to be the empty set, but there is one of it. Think of a set as a paper bag containing its members. The empty set is an empty paper bag. The set whose only member is the empty set is a paper bag containing an empty paper bag. Which is different: it's got a bag in it (see diagram).

The key step is to define the number 2. We need a uniquely defined set with two members. So why not use the only two sets we've mentioned so far: ? and {?}? We therefore define 2 to be the set {?, {?}}. Which, thanks to our definitions, is the same as {0, 1}.

Now a pattern emerges. Define 3 as {0, 1, 2}, a set with three members, all of them already defined. Then 4 is {0, 1, 2, 3}, 5 is {0, 1, 2, 3, 4}, and so on. Everything traces back to the empty set: for instance, 3 is {?, {?}, {?, {?}}} and 4 is {?, {?}, {?, {?}}, {?, {?}, {?, {?}}}}. You don't want to see what the number of dwarfs looks like.

The building materials here are abstractions: the empty set and the act of forming a set by listing its members. But the way these sets relate to each other leads to a well-defined construction for the number system, in which each number is a specific set that intuitively has that number of members. The story doesn't stop there. Once you've defined the positive whole numbers, similar set-theoretic trickery defines negative numbers, fractions, real numbers (infinite decimals), complex numbers... all the way to the latest fancy mathematical concept in quantum theory or whatever.

So now you know the dreadful secret of mathematics: it's all based on nothing.

Ian Stewart is emeritus professor of mathematics at the University of Warwick, UK

Cuortesy of New Scientist