Thursday, December 15, 2011

Blog Crawl Gems

This Week's Treasures

First, an entertaining post by Thoughtomics:  “Yeti Crabs grow bacteria on their hairy claws”.  It seems Yeti crabs do their mysterious “dance” to provide nutrients to methane- and sulfur-metabolizing bacteria living on their claws.  So why would the crabs do this? ... to grow food.  [This makes me wonder why they are considered symbionts.  Are cattle symbiotic with humans?]  Included are several short videos of Yeti crabs “feeding” bacteria with their curious claw-waving, eating bacteria, and possibly fighting or mating.

Small Things Considered also posted about symbiosis and sulfur-oxidizing bacteria:  "A Wormful of Bugs".  Paracatenula is a flat worm that has no mouth nor gut but rather a sack filled with H2S-metabolizing bacteria that provide its food.  I won’t give away the rest of the story, it is much better told by Moselio Schaechter.  Symbiotic relationships with sulfur oxidizing bacteria are widespread, involving diverse organisms including ciliates, arthropods, mollusks, a variety of worms, and even an archeon ... and of course Yeti crabs.   And there are more wonderful surprises ahead I’m sure.

The Artful Amoeba has an interesting post about the hazards of air-borne Red Tide -- the Red Tide Tickle -- as well as some natural history of the blooms and the dinoflagellates involved.  The post ends with an inexplicable video of a dinoflagellate waving its flagella while Billy Holiday sings Lover-man, oh where can you be.

Moving to the geological ... surely the most puzzling post of the week was by Sandatlas, with photos of the crater-like Makhtesh Ramon in Israel.  The mystery is in the middle of the “crater” where there are outcrops of  columnar sandstone.  Columnar sandstone???  ... bizarre enough that readers quickly responded with comments and hypotheses, but still no explanation.  Surely there must be one ... ??

In "Why Sugar Makes Us Sleepy (And Protein Wakes Us Up)", Jonah Lehrer of The Frontal Cortex describes research on the effects of sugar vs protein on the neuropeptide orexin, the lack of which can make us tired and slow our metabolism, among other things.  And yes -- sugar ingestion results in decreased activity of orexin neurons, while protein stimulates them.  Now that we better understand the mechanisms underlying the drawbacks of refined sugar, maybe it will be easier to turn down that quick-but-short-lived energy boost for something more lasting.  Reach for the almonds!

Finally, way back on November 29 Botany Photo of the Day featured a black bear feasting on dandelions (Taraxacum officinale); dandelions are known to be tasty treats for bears (is there an orexin story here too?).

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