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Tuesday, November 24, 2015

Getting Testy for Selenium: The Brain-Testes Struggle for The Element with Atomic Number 34

      Selenium, from Selene, the Greek goddess of the moon, is a gray crystalline element with atomic number 34.

      A recent study shows that, in mice, both the brain and the testes compete for selenium when selenium is scarce.  In selenium-depleted male mice, testes use up most of the selenium, leaving the brain in the lurch, scientists report in the November 18, 2015, Journal of Neuroscience.

     Since most people in the U.S. get plenty of selenium via food grown in the selenium-rich Great Plains, the correlation of this issue from mice to human data has not been confirmed.

     In fact, selenium levels which are too high are more of an issue for human health. Levels higher than 400 mg (edit: 400 mcg) a day can lead to selenosis. Supplements have been purported to help with everything from increasing antioxidants to preventing lung cancer so that misuse of selenium supplements has become a problem.

       Selenium has also been studied for the treatment of dozens of conditions from asthma to arthritis to dandruff to infertility. However, the results have been inconclusive. Selenium is naturally occurring in many foods, most prominently in Brazil nuts and these foods:

       Selenium is also the name of a browser automation system released in mid-October of this year. The name Selenium comes from a joke made by one of the creators, in an email, mocking a competitor named Mercury, noting that you can cure mercury poisoning by taking selenium supplements. And a new name was jokingly born!

           Have you heard of selenium's "magical powers?" Have you discovered the browser automation system Selenium? And lastly, what is the coat doing on the first selenium image?

Almost a full moon out there,
Selene, er, Steph

Making "Function Boxes" with second graders--an introduction to algebra: Input and output on the construction paper strips with "magic" happening inside the shoebox. F(x) has a wonderful effect ;-).

Tuesday, November 17, 2015

Red Ember Mine in Massachusetts: "Gar"-net Almandine Versus Trout Almondine

     Red Ember Mine garnets were discovered in the last six years in the town of Erving in Franklin County in western Massachusetts.

     The spectacular gems are highlighted and backlit in the surrounding black graphite matrix in the above image. Without the backlighting they appear more purplish in color:

         Garnets are a group of nesosilicate minerals that are used both as gemstones and as abrasives. The 6 different types of garnets are pyrope, almandine, spessartine, grossular, uvarovite and andradite. The Red Ember Mine garnets are primarily almandine (hence "gar" (the fish) net almandine.) No, no fishnets are involved. ;-)

      The first three garnet types are in one solid solution series and the last three are in another. Neither series is associated with trout almondine :-).

      The word garnet is derived from its color. The deep red color of some garnets reminded the French of a red-skinned fruit. In early French, the fruit was called pomme grenate or "seedy apple." This later became pomegranate in English.

      The early French word grenate, meaning "seedy," is the source of the adjective grenat, meaning "red like a pomegranate." This word was then used as a noun to refer to the deep-red gemstone. When transferred into English, grenat became garnet. 

         As we've discussed here at PEOTS before, color is not a reliable mineral characteristic. Garnet actually occurs in a variety of colors from red to orange to yellow to green to indigo to violet. Blue garnets are extremely rare and tend toward indigo:

             A black to gray graphite matrix for garnets, as in western Massachusetts, 

shows off the garnets extraordinarily:

       Have you seen garnets in colors other than pomegranate? Or, perhaps, have you seen the Red Ember Mine garnets? I sense another field trip in our future. . .

        And here's an image of the "Subway Garnet" (or whatever you'd like to call it) found in Manhattan, NYC, and housed at the American Museum of Natural History:

Emberly yours,

P.S. Speaking of field trips, here are a few images of cryptobiotic soil from David in Utah as well as one bodacious cairn:


And multiple multiple cairns:

Tuesday, November 10, 2015

Coal "Miner's" Canyon, Arizona: Tuba City's Pancake Geology Surprise

        Whoa. This "striking" image was my first introduction to Coal Mine Canyon on the Navajo Indian Reservation near Tuba City, in northeast Arizona. Have you heard of this magical, amazingly-tinted place before? Ok, now I'm just making up words. . .

      Well, you know what I'm thinking, right? 

       Field trip! Mom and I were already planning a trip to the Great Sand Dunes, CO, and to Santa Fe, Taos, Abiquiu, and Albuquerque, NM, in the spring of 2016. What's another 320 miles further west of the Albuquerque when this adventure awaits?!

 Really, whoa.

      Whoa. Whoa. Whoa!


         Whew! Just had to get that awe out of my system. Wait, one more. . .

     It is a breath-taking, stark and yet inviting, clear example of "pancake geology, with oldest rocks on the bottom of the stack and youngest rocks on top." One may easily follow those red marker beds in the foreground of the above image all through the canyon. It's easy to see which way the beds are "striking" or trending and that these beds dip very little in any direction. Drop some water (or maple syrup ;-)) on top of one of those beds and it just sits there or dribbles ever do slowly down one side of the stack. . .


         More specifics on how to get to this spectacular edge of the Painted Desert in the vicinity of Georgia O'Keeffe country just to the east in NM are described in this link to lesser-known vistas of the southwestern U.S.

        Today's post honors my mom, June, recovering after 6 days in the cardiac unit (she is doing much better now) and my friend-since-second-grade, Liz, also recovering from recent surgery. The three of us will report on Coal Bed Canyon in the spring. . .and have a stack of pancakes, syrupy sweet, if that strikes our fancies ;-)..[We may need to bring our own real maple syrup, of course]. 

      Here's to much healing, Mom and Liz!

Love may be a many splendored thing . . . . .but geology is a many layered thing,


>>>>>> Chemistry Month with Kindergartners:

 "Is it Alive?: Honeycombs, Carbon-Rings, and Mystery Containers" <<<<<<<

Wednesday, November 4, 2015

Bioturbation: The Worms Crawl In, The Worms Crawl Out

       Bioturbation is the reworking of soils and sediments by animals (including worms, snakes, trilobites, and crustaceans) or plant roots. The worms crawl in, the worms crawl out in these churned, turned over and under soils: check out this bioturbation video and watch the burrowing worms in action.

         These ancient dirt churners were recently determined to have taken much longer to bioturbate than originally thought, by millions of years.

       "For years, scientists thought bioturbation commenced in earnest with the Cambrian Explosion, 541 million years ago, when the complexity and diversity of animal species began to expand dramatically."

        "But that wasn’t the case. In a new study published in the journal Nature Geoscience, researchers found that major bioturbation did not occur until at least 120 million years later, during the late Silurian Period."

      Dr. Lidya Tarhan and researchers at Yale University propose that "Delayed bioturbation may have been responsible for regulating marine sulfate and atmospheric oxygen levels. A previously proposed drop in surface oxygen levels may be tied to the onset of extensive bioturbation, given that “oxygen is directly tied to the burial of organic carbon,” Tarhan said. “Less burial of organic carbon, due to bioturbation, means that more oxygen is used to respire or burn through that carbon, and thus oxygen decreases.”"

      Thank heavens for worms and other bioturbators!

     And of course, there's evidence of mass bioturbation (wait for it. . .):

As the Worm Turns,

       I am not especially fond of the color pink, but I do like these kindergartners' style for our "NOVEMBER is CHEMISTRY MONTH" experiment with Chromatography and ROY G BIV.