Starmer Shreds Repeal Bill. Barium, Breastfeeding, Neanderthals and Desmids

Desmid - Closterium species with barium sulfate crystals in vacuoles at ends

Hurricane Irma continues to barrel its way towards Florida, leaving mass destruction behind and mass evacuation ahead.

Notable Brexit article in Huffington Post and other news is Keith Starmer's devastating critique of the EU repeal bill (http://www.huffingtonpost.co.uk/entry/keir-starmer-brexit-bill_uk_59b1435ce4b0b5e531041cdc). He pointed out that the bill would effectively give ministers the right not just to change incorporated EU laws without  parliamentary approval. It could extend to ANY LAW that does not "a. Impose or create taxation, b. Make retrospective provision, c. Create a relevant criminal offence, or d. Amend, repeal or revoke the Human Rights Act 1998 or any subordinate legislation made under it." The debate will continue on Monday 11th and the bill will be put to the vote.

I processed yesterday's photographs of the desmids, sickle celled algae that were abundant in my little pond. Looking at the tips of the desmids, I could see the circular vacuoles which contained little particles that move around randomly due to Brownian motion when you look at the specimens live. These are apparently crystals of barium sulfate, more familiar as the white thick barium meal given to you when you have your stomach and intestines x-rayed, (to make them stand out. The barium sulfate absorbs x-rays). Why and how do desmids create crystals of barium sulfate in in their vacuoles? It took quite a bit of googling before I found some answers.

Soluble barium is present at low concentrations in food and water. It is harmful at high concentrations. When we take ingest it in a soluble form, it is readily absorbed and can end up in our teeth bones and teeth (http://www.who.int/water_sanitation_health/dwq/chemicals/barium.pdf). In fact, this was used to determine the breastfeeding habits of Neanderthals by looking at infant teeth. When in the womb, barium is prevented from crossing over to the baby. When breastfeeding begins, barium is taken up as a minor component of the calcium rich milk and is deposited in the infant teeth. When weaned, the amount of barium taken up decreases, so less is deposited in the teeth. Neanderthal children appeared to be weaned starting at about 7 months, with milk supplementation for a further 7 months. In humans in non-industrial societies, breastfeeding continues to an average age of about 2.5 years (https://www.nature.com/news/infant-tooth-reveals-neanderthal-breastfeeding-habits-1.13047). It is ironic that in our modern industrial society, we have reverted to a more Neanderthal breastfeeding strategy, with breastfeeding finishing soon after 6 months.

Back to the desmids. Desmids take up calcium, strontium and barium from the water they live in and export the mineral ions to the vacuoles. The vacuoles already have a high concentration of sulfate ions which react with the incoming minerals and produce sulfates of calcium, strontium and barium. Barium sulfate is practically insoluble and therefore precipitates, forming crystals. The strontium sulfate is slightly more soluble but can co-precipitate with the barium sulfate. The calcium sulfate remains in solution as it is water soluble. This accumulation of barium and strontium was of interest to a research group led by Derk Joester back in 2011. They were looking at using desmids for bioremediation, the removal of pollutants, such as radioactive strontium. https://helix.northwestern.edu/article/discerning-desmids.

The shape of the barium crystals is determined by the ratio of magnesium ions to sulfate ions. If the ratio is 1:1 or less, the crystals formed are rhombic, this is the form seen in Closterium, the desmids that I found.  If the magnesium ion:sulfate ratio is 10:1 or greater, then hexagonal crystals are formed, as in the desmid Micrasterias. http://rspb.royalsocietypublishing.org/content/238/1292/203