Monthly Archives: February 2012

Colloquium or presentation, Physics and Astronomy at Western What's Happening

Physics & Astronomy Colloquium – next TUESDAY, 7th Feb. – DR. TODD STEVENS, Robarts

Poster: http://www.physics.uwo.ca/colloquia/Colloquia%20Notices/2011_2012/STEVENS%20Research%20Talk.pdf

 

Western University
DEPARTMENT OF PHYSICS AND ASTRONOMY

 

PHYSICS & ASTRONOMY COLLOQUIUM

 

Date:          Tuesday, 7th February 2011
Time:          1:30 p.m.
Location:    Physics & Astronomy Seminar Room 22

 

Dr. Todd Stevens
Robarts Research Institute
Imaging Research Laboratories

“Accelerated high angular resolution diffusion imaging using compressed sensing: Crossing fiber data you can trust in a time you can afford”

 

ABSTRACT

 

There are a large number of neuroscience and neurology applications that would benefit from robust functional brain connectivity information. To substantiate and enhance functional MRI (fMRI) analyses of neural circuitry, diffusion–weighted MRI can provide information about the underlying white matter connectivity architecture. However, conventional diffusion tensor imaging (DTI) techniques are not capable of characterizing the diffusion of voxels that contain multiple crossing fibers—a situation that is known to occur in up to 30% of voxels acquired with typical diffusion imaging resolutions. Consequently, network tractography information generated from DTI data is prone to inaccuracies.

High angular resolution diffusion imaging (HARDI) schemes more finely sample the diffusion field to allow for more complete characterization of intra–voxel crossing fibers. The principal drawback of HARDI techniques is long scan times that preclude the acquisition of both fMRI and diffusion data in a reasonable exam time. Advantageously, diffusion information is amenable to dramatic acquisition accelerations using a new approach called compressed sensing (CS). Using CS–based acquisitions, accurate tractography maps based on HARDI information can be acquired at the lower acquisition costs of typical DTI.

This talk will introduce the concepts of CS-HARDI as well as provide details on the development roadmap for establishing and validating this technique, and will briefly describe some potential applications of this technique in the context of existing research interests at Western.

Physics and Astronomy at Western Blog, Physics and Astronomy at Western What's Happening

Do the math first please! #Starbucks versus #TimHortons who’s cheaper? #caffeine

You are constantly bombarded with propaganda convincing you the Tim Horton’s is the warm-hearted little guy coffee maker for the people while rich people with money to burn go to Starbucks. While it is true that my Bob-Bodum-brewed cup of morning Kona is cheaper and much better than either, if you can’t roll your own I argue save money and go to Starbucks.

Huh? No, this has nothing to do about Tim’s changing the cup sizes around. Let’s compare the brews under the following assumption: we are drinking coffee for the caffeine. Taste is subjective, but caffeine is caffeine and if this isn’t a prime reason most of us are coffee drinkers, then I invite you to have a big mug of Joe right before bed. Ok, Mrs. Sica can do that but most of us can’t. And study after study shows that overall coffee has mostly positive health benefits.

So, a 20 oz Timmie’s (which I believe is now called a Large) is about $1.60 and has about 200 mg of caffeine. A Starbuck’s Venti is the same size and will set you back like $2.10, but has about 400 mg of caffeine. There you go, 25% more coin for a Bucky for 2x the buzz. Which coffee is the bargain!

Just found out that in comparing these numbers remember: your mileage may vary. Here’s an interesting story from NPR in the States about the large variations in caffeine content: http://www.npr.org/templates/story/story.php?storyId=6155178. For instance:

The study also found that Starbucks’ caffeinated breakfast blend, purchased at a Florida store, varied greatly in its caffeine content from day to day. One day, a 16-ounce cup had 259 milligrams of caffeine. Another day, the same size coffee contained 564 milligrams.

So given the error my initial reaction was to be safe and bring a thermos, but the article argues that more like 100 mg might be a optimum dose. Since they are still working on my new office here, maybe I can get them to plumb in some lines for a proper espresso maker so I can spread out my daily buzz!