Fluoride and Fluorite: First Change since 1962: Decreased Levels of Recommended Fluoride in Drinking Water by the United States

          On Monday, April 27, 2015, the U. S. Department of Health and Human Services decreased the recommended amount of added fluorite in drinking water to about half the original recommendation. It is the first change in the recommended amount since 1962.

       
          The main documented side effect to over-fluoridation is fluorosis, a condition marked by white marks on the teeth. There are proven great benefits to low fluoride amounts to decreasing dental caries. Most people in the U. S are already getting fluoride directly on their teeth in the form of toothpaste and dental rinses. The NPR link above notes some believe fluoridation at higher levels is linked to other problems including thyroid issues, skeletal fluorosis, and ADHD.

           Much of the western world has already eliminated or decreased fluoride amounts in water supplies. There are some areas of the world that have naturally occurring fluoride which is over 1.5 mg/l (See world map here.) The high fluoride levels are linked to types of granite with the naturally occurring fluorite mineral (the purplish mineral in the pinkish granite below):

           The mineral fluorite, CaF2, is a member of the halide sequence.

          And, of course, fluorite is the namesake poster child for fluorescence under ultraviolet light:

          I am curious to hear about your views on the fluoride controversy. What is yours? Surely, the decreasing of the acceptable level by half is significant. 

Going with the fluo,

Steph

Capitanian: A Sixth Major Extinction 262 Million Years Ago?

      One of the first things geologists learn about is the major extinction at the end of the Permian Period (and Paleozoic Era) 250 million years ago. 96 percent of all species died during that mass extinction.

       Now geologists have discovered new evidence that may point to another extinction during the mid-Permian, 262 million years ago, just 12 million years before the major Permian-ending event. An April, 2015, Geologic Society of America (GSA) paper (Lead author David Bond) notes that the "Capitanian" saw the extinction of 87% of all brachiopod species.

        The Capitanian was named 20 years ago based on research in tropical to sub-tropical areas in China and elsewhere and believed originally to be more localized. Newest research in northern Norway suggests that this extinction may actually be more global (though several dissenters have commented on the publication in the well-respected GSA paper).

      
          Dr, Bond et al  write that the Capitanian extinction was likely triggered by the eruption of the Emeishan Traps, located in the southwestern Chinese province of Sichuan. Volcanic eruptions release large amounts of carbon dioxide, causing ocean acidification. Seafloor oxygen depletion may also have played a role.

             The major shift after the acidification and oxygen depletion was from domination of brachiopods to domination by bivalves after the Capitanian extinction:

      Brachiopods and bivalves differ in the number of adducting muscles, the way they eat, in their very classification, and in the symmetry of their shells. The two shells of bivalves are mirror images of each other; they are not in brachiopods.

          So, why were bivalves better suited than brachiopods for life after the Capitanian? Any guesses?

Shellfishly (and sleepily),

Steph

Exquisite Dating Tool: Zircons as Indicators of Earlier Closing of the Land Bridge Between North and South America

          New research indicates that the connection between North and South America was created 13-15 million years ago rather than 3-5 million years as previously thought. The age of zircons was the main indicator of the much older closing age. Here's an image of a  zircon (greenish elongate diamond) in crossed nichols polarization:

           Zircons are crystals that form when magma cools. Newly-formed zircons contain some uranium, but no lead.  Therefore, any lead found in an old zircon must have originated in the radioactive decay of uranium. Thus, zircons are a favorite tool for dating in geology. (as well as dinner and a movie ;-)).

          Zircons found in streams in Colombia and Panama have dated the closing of the gap and formation of the "land bridge" at 13-15 million years.

           The biggest mystery is why animals, especially mammals like this racoon ancestor, 

Chapalmalania, 

did not make the mass movement across the land bridge until 3-5 million years ago (as seen in the fossil record). Perhaps the "land bridge" was more like a series of volcanos with shallow waters in between so it took ten million years for a solid, continuous land bridge to form. 

            This research was performed by Camilo Montes et al. This article also contains a link to terror birds (if you dare). [And a new terror bird species has just been discovered as reported on April 13, 2015.]

             Any ideas as to what was going on in the 10 million years between the possible closing of the North and South American continents and the mass mammal migration (say that 5 times fast!)?

Zirconly,

Steph

Yawn, Yawn, Yawn: Emotional Closeness in Wolves and Other Species

     Here's hoping this post will make you yawn. 

       Researchers at the University of Tokyo collected data to show that yawns among wolves are related to emotional connection between individuals. The stronger the bond-- the more likely the yawn. The research is discussed here.

        There's evidence of interspecies transfer when it comes to yawns as well.

      

       Savor the etymology of yawn:

c.1300, yenen, yonen, from Old English ginian, gionian "open the mouth wide, yawn, gape," from Proto-Germanic *gin- (cognates: Old Norse gina "to yawn," Dutch geeuwen, Old High German ginen, German gähnen "to yawn"), from PIE *ghai- "to yawn, gape" (cognates: Old Church Slavonic zijajo "to gape," Lithuanian žioju, Czech zivati "to yawn," Greek khainein, Latin hiare "to yawn, gape," Sanskrit vijihite "to gape, be ajar"). Modern spelling is from 16c.

       May your day have lots of  yawns with whatever species you encounter today.

Here's to many more yawns,

Steph

And, seen at the Smith President's House yesterday (not far from the river otters):

Slab Melting: Quite Continental!

       Plate tectonics theory has generally espoused that all continental crust, rich in silica, has been recycled. 

     Virginia Technical University geologists have published research today indicating some of that continental crust may actually be new or "juvenile" crust.

       Some of the type areas for this discovery are in Costa Rica and Panama:

The March 31, 2015, research includes this description of continental and oceanic crust:

     "The researchers used geochemical and geophysical data to reconstruct the evolution what is now Costa Rica and Panama, which was generated when two oceanic plates collided and melted iron- and magnesium-rich oceanic crust over the past 70 million years."

      "Melting of the oceanic crust originally produced what today are the Galapagos islands, reproducing Achaean-like conditions to provide the "missing ingredient" in the generation of continental crust."

     "The researchers discovered the geochemical signature of erupted lavas reached continental crust-like composition about 10 million years ago. They tested the material and observed seismic waves traveling through the crust at velocities closer to the ones observed in continental crust worldwide."

        The study continues "It raises questions about the global impact newly generated continental crust has had over the ages, and the role it has played in the evolution of not just continents, but life itself. 

        For example, the formation of the Central American land bridge resulted in the closure of the seaway, which changed how the ocean circulated, separated marine species, and had a powerful impact on the climate on the planet."

        Older names for continental and oceanic crust are SIAL and SIMA, respectively. Sial is a short for silica aluminum (or aluminum silicate) and sima is short for silica magnesium (or magnesium silicate). The sial is less dense than the sima. And now, researchers have shown that some of that sial is juvenile. 

SIAL LATER!

Steph




        

A Picture a Day Picnic: Down the NASA Rabbit Hole with the Pelican Nebula and Opals

     Today I discovered this "A Picture a Day" site from NASA. Today's post on the Powers of Ten includes an intriguing video moving away and inward from a picnic by the powers of ten. Each post includes extraordinary images and descriptions by astronomers.

          The past posts from the NASA site lead you down many a fascinating rabbit hole. Click on the "Discover the Cosmos" link at the NASA site to enjoy exploring!

           The March 4, 2015, image from the NASA site of pillars and jets in the Pelican Nebula is particularly striking:

          And this particular Rabbit Hole led me to the Rabbit Hole Mine in Black Desert, Nevada, (red pin below) near the Burning Man Festival site. Based on what I know about the Burning Man Festival, their proximity cannot be an accident!

          The Rabbit Hole Mine is rich in sulphur, alunite, cinnabar, gypsum and opal.

           The powers of ten may also provide a colorful journey from opals to nebulae . . .and back, via the rabbit hole.

            Let me know your favorite past image on the NASA site. . .and do enjoy your trip down the rabbit hole. Please--come back!

Enjoy the ride,
Steph

Wearin' o' the Green: Malachite and Mallows

          On this St Paddy's day, malachite, especially this form of the copper carbonate  hydroxide replacing the limestone of stalactites or stalagmites, is our featured green mineral.

          Malachite's name derives from the Greek Μολοχίτης λίθος molochitis lithos, "mallow-green stone", from μολόχη molōchē, variant of μαλάχη malāchē, "mallow". The mineral was given this name due to its resemblance to the leaves of the mallow plant. You've likely seen these (marsh) mallows ;-) before:

            The resembance to other forms of malachite is remarkable:

           Malachite is fairly common and was used as a mineral pigment in green paints from antiquity until the 19th century. The pigment is moderately light-fast, very sensitive to acid, and varies in color.  

        It has also been used extensively in jewelry (with no shellacking ;-)):

          One of the greatest occurrences of malachite is in the Ural Mountains in Russia. It is mined fairly easily with other copper minerals, especially azurite.

           Uploading images on Blogger has been hiccuping here all night--must be the green beer at the local Irish pub.

              Enjoy all the green today and all the way into spring!

Happy St Paddy's Day all ye Malachites!

Steph

And footware for 3/17 is now easy as pi:

SpongeBob SquarePants Fungi (Really!) and Possible Sponge Precursor

          Spongiforma squarepantsii is a species of fungus, genus Spongiforma. It was found and described in 2011 in Malaysia. It produces sponge-like, rubbery orange fruit bodies that have a musky or fruity odor.

      And the name comes from the cartoon character SpongeBob SquarePants, of course.

      Like a sponge, these fungi resume their original shape if water is squeezed out. The spores, produced on the surfaces of the hollows of the sponge, are almond-shaped. 

       I discovered the Spongiforma squarepantsii fungi in researching this microfossil which may be a precursor [put your cursor in front ;-)] to the sponge family itself:

      This well-preserved 600-million-year-old fossil shows actual cells that make it an excellent candidate for an ancestor of sponge animals.

      The new discovery, named Eocyathispongia qiania, is a single fossil found in China. Yet its three tubular chambers arising from a base and its visible parts of cells resemble sponges according to  Zongjun Yin et al of the Chinese Academy of Sciences in Nanjing  in the yesterday's Proceedings of the National Academy of Sciences.

         Looking at the fossil with X-rays and scanning electron microscopy (SEM), the researchers saw cells that resemble modern sponges’ outer structural elements, called pinacocytes (still looking for a pinacolada connection there via pineapple bract structure ;-) ). 

          The link to the Science News article includes this description of this possible sponge ancestor:

         "Some surface cells are signs of pores, like those that let water swoosh into modern sponges. And a patch inside one of the tubes has pits encircled by raised collars. These could be an early version of the cells called choanocytes, distinctive cells in modern sponges that move water through the animal."

           Further examples and connections are needed to make a definitive connection from this single microfossil to the sponges. . .perhaps to SpongeRobert SquarishPants?

SBSP to all you fun guys,

Steph


          

Light: Particle/Wave? . . .Topographic Map?

      The first-ever image of light behaving as both a particle and a wave was published yesterday in Nature Communications and is shown below:

      This short summary article from Science Daily describes the procurement of the image by researchers at Ecole Polytechnique Fédérale de Lausanne. Quantum mechanics in bright , primary colors!

      The first thing I noted was the similarity to contour lines on topographic maps:

        Closing all those circles from contour lines/waves into pinnacles/particles brought me to Topo Gigio's brother, a quantum mechanic ;-) :

         

            Off to enjoy time with my brothers, my son, and my mom. 

            Happy March! Enjoy March fo(u)rth tomorrow, the most assertive day of the year and the anniversary of my son's beginning of his first trip around the sun. 

March Forth and Prosper,
Steph



         
      

From Bdellium to Bdelloid Rotifers: Scrabble and Science Merge

           The search for Scrabble words starting with 'bd' brought me to both bdellium and bdelloid rotors (and, ultimately, back to our tardigrade friends).          

          Bdellium is a semi-transparent oleo-gum resin extracted from Commiphora trees growing in Ethiopia, Erythrea and sub-Saharan Africa. It is also an ingredient in myrrh.

        

            Bdelloid rotifers or "bdelloids" are asexual minute invertebrates found in freshwater habitats worldwide. There are over 450 described species. 

      

           Bdelloids share the ability to survive in dry, harsh environments by entering a state of desiccation-induced dormancy (anhydrobiosis) at any life stage (similar to the topic of an earlier post, the tardigrades ). This photo of one bdelloid species brought me right back to those Michelin Man tardigrades. 

       Like tardigrades, bdelloid rotifers are microscopic organisms, typically between 150 and 700 µm in length. They are slightly too small to be seen with the naked eye.

        Bdelloids reproduce by ingesting the DNA of other organisms like bacteria, fungi, and algae as described here.

       Bedelloid is from the ancient Greek βδέλλα , bdélla, meaning “leech."

       It's my first experience with words starting with 'bd." How about you? Have you seen bdellium in the ingredients list for your myrrh or run into any of the 450 species of bdelloids?

Happy 'bday' bdelloids and bdellium,

Steph