51吃瓜 of the Day
euxinia
noun
anoxia, or depletion of oxygen, in a body of water, along with a high level of hydrogen sulfide, a condition toxic to aquatic organisms.
More about euxinia
Euxinia 鈥渁noxia in a body of water鈥� is the namesake of the Latin term Pontus Eux墨nus 鈥渢he Black Sea,鈥� where euxinia is often found in the deeper water. The Latin name is adapted from Ancient Greek Pontos Eu虫别卯苍辞蝉, literally 鈥渉ospitable sea,鈥� but the story does not end there. It appears that the 别耻虫别卯苍辞蝉 portion, meaning 鈥渉ospitable鈥� and composed of eu- 鈥済ood鈥� and 虫别卯苍辞蝉 鈥渇oreign鈥� (a variant of 虫茅苍辞蝉; compare English xeno-), was originally a euphemism for Pontos A虫别卯苍辞蝉 鈥渋nhospitable sea.鈥� Alternatively, the meaning of the a虫别卯苍辞蝉 element could be folk etymology, that is, incorrectly derived from an unrelated term; the name for the Black Sea in Avestan, an ancient Indo-European language of the Iranian plateau, contained the element 补虫拧补脓苍补- 鈥渂lue, dark,鈥� and speakers of Ancient Greek could have misinterpreted this word as their own a虫别卯苍辞蝉. Euxinia was first recorded in English in the early 1950s.
how is euxinia used?
The result is that euxinia may be more widespread in the present-day oceans than previously thought 鈥�. The midwater oceanic oxygen minimum layers become especially important where they intersect the continental slope. The combination of suboxic overlying water and sulfide-producing sediments could result, in itself, in the development of extensive areas of oceanic euxinia. This does not seem to be happening at present, although it may have occurred in the past and, if the current global warming trends continue, may occur in the near future.
鈥淎fter oxygen in the ocean was used up to decompose organic material, microbes started to 鈥榖reathe鈥� sulfate and produced hydrogen sulfide, a gas that smells like rotten eggs and is poisonous to animals,鈥� said UC Riverside Earth system modeler Dominik H眉lse. As ocean photosynthesizers鈥攖he microbes and plants that form the base of the food chain鈥攔otted, other microbes quickly consumed the oxygen and left little of it for larger organisms. In the absence of oxygen, microbes consumed sulfate then expelled toxic, reeking hydrogen sulfide, or H2S, creating an even more extreme condition called euxinia.
euxinia
caoutchouc
noun
a highly elastic solid substance, light cream or dark amber in color, polymerized by the drying and coagulation of the latex or milky juice of rubber trees and plants.
More about caoutchouc
Caoutchouc 鈥渞ubber鈥� is a borrowing from French, which adapted the term from obsolete Spanish cauchuc (modern caucho), and from here is where the history becomes obscure. Because the Indigenous languages of the Americas have overall not received enough documentation and analysis, linguists assign caoutchouc to multiple possible languages, and there is substantial disagreement among sources. One proposal is that caoutchouc derives from Tupi, which we learned about from the recent 51吃瓜 of the Day maringouin. Another possibility is an origin in Carib, a language of the Cariban family with several thousand speakers in northern coastal South America. Some reputable sources claim a derivation from Quechua, which we learned about from the recent 51吃瓜 of the Day pampero, but other sources eliminate that connection outright. Perhaps the only way to find the true, incontrovertible origin of caoutchouc is to support research in Indigenous languages, especially because 2022 marks the beginning of the UNESCO . What we do know is that caoutchouc was first recorded circa 1770s.
how is caoutchouc used?
Rubber was not exactly new. It had long been known to [Indigenous] South Americans 鈥�. Some rubber made its way to Europe, but mostly as a curiosity. In the 1700s, a French explorer brought the name “caoutchouc” from a local language .鈥� The scientist Joseph Priestley bestowed its common name when he noticed it rubbed pencil marks off paper.
At five o’clock on the evening of the 10th of August they put into the island of Cocos. They there passed a 鈥渟eringal.鈥� This name is applied to a caoutchouc plantation, the caoutchouc being extracted from the 鈥渟eringueira鈥� tree …. It is said that, by negligence or bad management, the number of these trees is decreasing in the basin of the Amazon, but the forests of seringueira trees are still very considerable on the banks of the Madeira, Purus, and other tributaries.
caoutchouc
ultramafic
adjective
(of rocks) containing iron and magnesium, with little or no silica.
More about ultramafic
Ultramafic 鈥渃ontaining iron and magnesium鈥� is a compound of the combining form ultra- 鈥済oing beyond what is usual or ordinary鈥� and the adjective mafic 鈥渞elating to rocks rich in ferromagnesian materials.鈥� Ultra- is borrowed from the Latin preposition 耻濒迟谤腻 鈥渙n the far side (of), beyond,鈥� while mafic is a coinage based on magnesium and Latin ferrum 鈥渋谤辞苍.鈥� The ultimate origin of magnesium is the Ancient Greek phrase (h膿) 惭补驳苍脓蝉铆补 (l铆thos) 鈥渢he stone of Magnesia,鈥� in which 惭补驳苍脓蝉铆补 denotes an uncertain location in either modern-day Greece or Turkey. From this same source, English inherits magnet and manganese. Latin ferrum is the source of modern Romance terms for 鈥渋ron鈥� (compare French fer and Spanish hierro) and is of obscure origin, though one hypothesis connects ferrum to English brass, and another connects it to a Semitic source akin to Hebrew barzel 鈥渋谤辞苍.鈥� Ultramafic was first recorded in English in the early 1940s.
how is ultramafic used?
Huddled up next to a small slice of muskeg, the cliffs glowed in a strange light. This was ultramafic rock, Birdman told us, placing his hand on a slab. Volcanic intrusions, brimming with iron that stained the rock red. This type of rock was as substantial as we could hope for. Our feet would stick to it even at a dangerous angle, but in places the weather was slowly crumbling the rock into tiny pebbles. We would have to be careful. We would have to respect the rock.
ultramafic