Things I've Learned: Sinistral Shells, Sweet Potatoes, & the Peace Sign

This week is my last one on ENT before I move onto my next rotation. With Tuesday off for Remembrance Day it's been a short one. Here are five non-ENT related things I've learned:

1. peace sign -- I learned on Remembrance Day that the peace sign originated as the logo of the 1958 British Campaign for Nuclear Disarmament (CND). It is a combination of the semaphore symbols "N" and "D".

   

   (http://funguerilla.com/wp-content/uploads/2010/05/Peace.jpg)

2. flag semaphore -- There's a scene in Anne of Green Gables (the movie, not the book) where Diana signals to Anne with two flags from across a field. Though Diana may not have been using standard semaphore, it's the scene that plays in my mind when I think of flag semaphore. For non-Anne fans, perhaps you're familiar with the Beatles album Help!, whose cover features the band members spelling out the title in semaphore. This telegraphy system, used widely in the maritime world of the 1800s, represents 30 alphabet characters and numbers by different positioning of two square hand-held flags (or rods, arms, ...anything will do!).

   

   (http://ehps4l.edublogs.org/files/2013/04/semaphore-alphabet-vector-112690-pfchez.jpg)

   

   (http://en.wikipedia.org/wiki/Help!_(album)#mediaviewer/File:Help.jpg)
3. sinistral shells -- In All The Light We Cannot See, Anthony Doerr writes: "...certain things compel people. Pearls, for example, and sinistral shells, shells with a left-handed opening." I turned to Wikipedia to find out why sinistral shells were so special. I learned that being asymmetrical, gastropod shells possess chirality (handedness). Over 90% are dextral (right-handed), though a small minority of species are sinistral (left-handed). Rarely species are found with mixed coiling, due to sinistral or dextral mutants. You can bet I'm going to pay attention to chirality the next time I see a shell!

   

   sinistral (left) & dextral (right) chiralities
   (http://en.wikipedia.org/wiki/Sinistral_and_dextral#mediaviewer/File:Neptunea_-_links%26rechts_gewonden.jpg)

4. yams vs. sweet potatoes -- I've always used these terms interchangeably, but when asked about the difference by @naturesteaparty on my Instagram photo of yam fries, I had to look it up. I stand corrected: I made sweet potato fries. Yams are edible tubers of the family Dioscoreaceae. Sweet potatoes, often referred to (incorrectly!) as yams in North America, are actually members of a different family. As shown by this Wikipedia table, it's not quite a "potayto, potahto" situation:

   

   (http://en.wikipedia.org/wiki/Yam_(vegetable))

   

   yam (left) & sweet potato (right)
   (http://www.ncsweetpotatoes.com/sweet-potatoes-101/difference-between-yam-and-sweet-potato/)

5. heat cramps vs. muscle cramps -- Heat cramps are painful irregular muscle spasms that usually arise from intense exercise in hot environments, particularly in the setting of inadequate fluid intake and electrolyte imbalance. The treatment is rest and rehydration with juice or an electrolyte-containing sports drink. A muscle cramp, or charley horse, is when a muscle suddenly contracts involuntarily, often secondary to overuse. A quick way to tell them apart? Massage exacerbates heat cramps, but alleviates muscle cramps!

What interesting stuff did you learn this week?