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Friday, February 22, 2013
Separated bike lanes, slower vehicle speeds greatly reduce bicycle injuries
Feb. 20, 2013 ? Using your bicycle to commute to work has numerous health and environmental benefits. Yet, the largest Canadian study on cycling injuries led by Ryerson University suggests cyclists are at risk of injury due to the lack of cycling infrastructure in large urban centres.
"Previous studies have focused on the measures such as helmets that reduce harm after a crash occurs," says Anne Harris, lead author of the study, who is an avid cyclist herself and an assistant professor with Ryerson's School of Occupational and Public Health. "Our study is one of the first to take a comprehensive look at how route infrastructure, particularly at intersections and major roadways, might influence the risk of cyclist injury in Canada."
North American cyclists are eight to 30 more times likely to be seriously injured while cycling than their counterparts in Germany, Denmark and The Netherlands. Harris says one explanation could be the availability of segregated bike lanes in those countries.
The major findings of the Ryerson's School of Occupational and Public Health study are:
Intersections -- safer
? Intersections at residential streets
? Cars travelling 30 km and under decreases the risk of injuring a cyclist by half
Intersections -- less safe
? Traffic circles: designed as a traffic calming measure, actually increase the risk of cyclist injuries. In the study, 19 out of 690 accidents occurred in Vancouver intersections with traffic circles
? Grade: roads that slope downhill are more dangerous than uphill roads
? Arriving at the intersection in the opposite direction of vehicular traffic
Non-intersections -- safer
? Separated bike lanes along major streets
? Bike routes with traffic diversion on local streets
? Bike-only paths separated from traffic
? Non-intersections -- less safe
? Streetcar tracks
? Downhill grade
? Construction at site
? Shared bike lanes or single bike lanes with parked cars present
The researchers also found that painted and shared bike lanes commonly found in Toronto offered no significant protection for cyclists.
"Our research demonstrates that transportation planners really need to segregate cyclists from motor vehicle traffic just as we use sidewalks to separate pedestrians," says Harris. "If people see cycling as a safer activity, they would be more encouraged to commute by bike, which makes them more active and healthy citizens."
Research Methodology
Harris and her co-authors, also cyclists, interviewed 690 cyclists injured in downtown Toronto and Vancouver between May 2008 and November 2009. According to Census data, nearly two per cent of people in Toronto and almost four percent in Vancouver commute by bicycle.
In the study, all of the cyclists sought medical attention at emergency departments with injuries ranging from minor to serious. Of the total number of cyclists, 211 were injured at intersections and 479 injured along roads or paths.
The researchers gathered two sets of data. First, they asked all of the cyclists to map the route they were injured on, and describe the details of their trip and their injury. Next, an observer visited one or two randomly selected locations along each route to coincide the injury site (if it was at an intersection or not). Specific details about each site were gathered such as the presence and type of bike lanes, grade of the road and traffic volume. Finally, the researchers performed statistical analyses to look at the relationship between route infrastructure and relative safety.
At the time of the study, both Toronto and Vancouver had cycling infrastructure typical of North American cities: shared bike lanes, local street bike paths, off-street paths and a few kilometres of physically separated bicycle routes beside major roads. Some of the features unique to Toronto were streetcar tracks on major streets, whereas traffic circles are common in Vancouver residential areas. Vancouver also has a helmet law for all ages, where it's optional for Toronto adult cyclists.
The study's co-authors are: University of British Columbia and University of Minnesota -- Conor Reynolds; University of British Columbia -- Kay Teschke , Peter Cripton, Hui Shen, Shelina Babul, Jeffrey Brubacher, Garth Hunte, Melody Monro; Simon Fraser University -- Meghan Winters; University of Toronto -- Mary Chipman, Lee Vernich; St. Michael's Hospital and University of Toronto -- Michael Cusimano; and University of Toronto and University Health Network -- Steven Friedman.
The study, published in the journal Injury Prevention, was funded by the Heart and Stroke Foundation of Canada and the Canadian Institutes of Health Research.
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The above story is reprinted from materials provided by Ryerson University.
Note: Materials may be edited for content and length. For further information, please contact the source cited above.
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Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.
Source: http://feeds.sciencedaily.com/~r/sciencedaily/living_well/~3/UhcfOHBgVYQ/130220131744.htm
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Online Learning Platform, edX, Goes International With The Addition Of Six New Schools
When it comes to online education and massive open online courses (a.k.a. "MOOCs"), Udacity and Coursera have stolen most of the attention. But they aren't the only two choices for voracious distance learners out there; in fact, the number of options has grown considerably.Source: http://feedproxy.google.com/~r/Techcrunch/~3/-iPVaBHjBdM/
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Thursday, February 21, 2013
The 'unparticle' might lurk in Earth's mantle
Marc Airhart (University of Texas at Austin) and Steve Jacobsen (Northwestern University)
Researchers used an experiment that relied on the electrons (red dots) in Earth's mantle to look for new particles, possibly the unparticle, that are tied to a new fundamental force of nature called the long-range spin-spin interaction (blue wavy lines). The white arcs represent Earth's magnetic field lines.
By Jesse Emspak
LiveScience
It's a good time to be a particle physicist. The long-sought Higgs boson particle seems finally to have been found at an accelerator in Geneva, and scientists are now hot on the trail of another tiny piece of the universe, this one tied to a new fundamental force of nature.
An experiment using the Earth itself as a source of electrons has narrowed down the search for a new force-bearing particle, placing tighter limits on how big the force it carries can be.
As an added bonus, if the new particle is real, it will shed light on processes and structures inside Earth, say study researchers from Amherst College and the University of Texas at Austin. The experimental results will appear in Friday's issue of the journal Science.
The new force of nature carries what is called long-range spin-spin interaction, said lead study author Larry Hunter, a physicist at Amherst. Short-range spin-spin interactions happen all the time: Magnets stick to the fridge because the electrons in the magnet and those in the fridge's steel exterior are all spinning around in the same direction. But longer-range spin-spin interactions are more mysterious. [Wacky Physics: The Coolest Little Particles in Nature]
The force would operate in addition to the four fundamental forces familiar to physicists: gravity, electromagnetism and the strong and weak nuclear forces. Some physicists think this new force exists because extending the Standard Model of particle physics ? a theory that defines the physics of the tiniest particles ? actually predicts as-yet undiscovered particles that would carry it.
The unparticle
There are three possibilities for where this force comes from. The first is a particle called the unparticle, which behaves like photons (light particles) in some ways, and like particles of matter in others. The second is one called the Z' (pronounced "Z-prime"), a lighter cousin of the Z boson that carries the weak nuclear force. Both unparticles and Z's arise from extensions of current physical theories. And the third possibility is that there is no new particle at all, but the theory of relativity has some component that is affecting spin.
The unparticle was first proposed in 2007 by Harvard physicist Howard Georgi. Particles have a definite mass, unless they are photons, which are massless. An electron or proton's mass can't change no matter how much momentum it has ? change the mass (and thus its energy) and you change the kind of particle it is. Unparticles would have a variable mass-energy.
Though scientists have not yet found a new particle tied to the force, they did see that the long-range spin-spin interaction had to be smaller by a factor of 1 million than earlier experiments showed. If the force exists, it is so tiny that the gravitational force between two particles such as an electron and a neutron is a million times stronger.
The normal, fridge magnet type of spin interactions, mediated by photons, operate only at very short distances. For example, magnetic forces drop as the inverse cube of distance ? go twice as far away and the strength of the force drops by a factor of eight. Long range spin-spin forces don't seem to decrease by anywhere near as much. Physicists have been looking for the particles that carry this kind of interaction for years, but haven't seen them. The Amherst experiment puts tighter limits on how strong the force is, which gives physicists a better idea of where to look.
Earth's electrons
Theorists had already known the force they were seeking would be weak and could only be detected over very long distances. So the scientists needed a creative way to look for it. They needed to find a place where tons of electrons were crowded together to produce a stronger signal.
"Electrons have a big magnetic moment," Hunter said. "They align better with the Earth's magnetic field, so they are the obvious choice." Anything that nudges the spins of electrons that line up with the Earth's magnetic field will change the energy of those spins by a small amount. [50 Amazing Facts About Planet Earth]
So the Amherst and University of Texas team decided to use the electrons that are in the mantle of the Earth, because there are a lot of them ? some 10^49. "People before prepared samples of spin-polarized neutrons and such," Hunter said. "Their source was close, and controllable. But I realized that with a bigger source you could get better sensitivity."
The reason is that even though only one in about 10 million mantle electrons will align their spin to the Earth's magnetic field, that leaves 10^42 of them. Even though it's not possible to control them the way one would in a lab, there are plenty to work with.
Electron map
The scientists first mapped out the spin directions and densities of electrons inside the Earth. The map was based on the work of Jung-Fu Lin, associate professor of geoscience at the University of Texas and a co-author of the new paper.
To make the map they used the known strength and direction of the Earth's magnetic field everywhere within the planet's mantle and crust. They used the map to calculate how much influence these electrons in the Earth would have had on spin-sensitive experiments that were done in Seattle and Amherst.?
The Amherst team then applied a magnetic field to a group of subatomic particles ? neutrons in this case ? and looked closely at their spins. The Seattle group looked at electrons.
The change in the energy of the spins in these experiments depended on the direction they were pointing. Spins rotate around the applied magnetic fields with a distinct frequency. If the electrons in the mantle are transmitting some force that affects them, it should show up as a change in that frequency of the particles in the lab.
Besides narrowing the search for new forces, the experiment also pointed to another way to study Earth's interior. Right now, models of Earth's interior sometimes give inconsistent answers as to why, for example, seismic waves propagate through the mantle the way they do. The fifth force would be a way to "read" the subatomic particles there ? and might help scientists understand the discrepancy. It would also help geoscientists see what type of iron is down there and the actual structure it has. "It would give us information that we mostly don't have access to," Lin said.
Editor's Note: This article has been updated to correct the last name of physicist Larry Hunter.
Follow LiveScience on Twitter @livescience. We're also on Facebook?and Google+.?
Copyright 2013 LiveScience, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.
Source: http://science.nbcnews.com/_news/2013/02/21/17047660-the-unparticle-might-lurk-in-earths-mantle?lite
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Hot Dad Alert! Chris Hemsworth Carries His Baby Girl
Chris Hemsworth steps out with his two leading ladies! Plus, see more photos of celebs spending time with their loved ones!
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Universal Background Checks Backed By Republican Rep. Joe Heck
WASHINGTON -- The prospects of passing an important part of President Barack Obama's gun control agenda improved a bit on Tuesday when a House Republican announced his support for universal background checks for firearm purchases.
"I think the idea of background checks across the board, I'm not opposed to them," Rep. Joe Heck (R-Nev.) told the Las Vegas Review-Journal. "And I disagree with people who say that this is going to be the first step to gun registration, which leads to gun confiscation. Look, about 40 percent of folks already undergo background checks when they get their guns. And that information is purged after a short period."
"Too many people just want to discount everything out of hand. And you can't. You've got to have a thoughtful discussion," he added. "You've got to look at what the definitions of each of these things are and how they will be applied before you say: 'I'm against universal background checks, or I'm against this, or I'm against that.' Look, we have a problem. Let's figure out the best way to address the problem. And to me the problem is.... making sure an individual who shouldn't have a weapon of any type ? because they have a propensity to commit a violent act ? doesn't get their hands on that weapon."
Heck's take on universal background checks, which have received the support of more than 90 percent of Americans in several public opinion polls, is notable for two reasons. The first is that he is among a small minority of Republicans who have now come out in favor of the proposal, which is the centerpiece of the president's plan to stem future gun violence and is the top legislative priority of gun control advocates. Secondly, it directly refutes the main talking point of the gun-rights lobby, which has warned that universal background checks will be a gateway to a federal registry of gun purchases and gun ownership.
The lawmakers drafting gun legislation are taking those concerns seriously enough that they're likely to include specific restrictions on what gun sellers can do with the information they gather through background checks. Heck is essentially saying that the fears driving those lawmakers to be so accommodating aren't entirely legitimate.
Other House Republicans who have hinted support for universal background checks include Reps. Mike Fitzpatrick (Pa.), Peter King (N.Y.), Peter Meehan (Pa.), Phil Gingrey (Ga.) and, to a lesser extent, Joe Duncan (Tenn.).
A request for comment from Heck's office asking for elaboration on his remarks to the Review-Journal was not immediately returned.
Also on HuffPost:
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Source: http://www.huffingtonpost.com/2013/02/20/universal-background-checks-joe-heck_n_2725239.html
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NASA Lost Communications With the International Space Station ...
At 9:45 this morning, during a software update to the International Space Station's flight computers, one system malfunctioned?causing a loss in communication between NASA on the ground and NASA in space. According to Expedition 34 commander Kevin Ford, "the station's status was fine and that the crew was doing well," NASA was able to learn as the ISS flew over Russian ground stations a bit before 11 am. According to CNN's Stephanie Gallman,?NASA will be able to communicate with the astronauts on board each time the ISS passes over Russian ground stations, every 90 minutes or so.?According to Gallman, "This is not an unprecedented event, but any loss of communications not good."?There are currently six men living on the space station, three Russian cosmonauts, two Americans, and one Canadian.
Update 12:44 EST: NASA says that communication has been restored.
Read more at The Atlantic.?
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