Crystals of xenon tetrafluoride (XeF4).

The noble gasses (helium, neon, argon, krypton, xenon, and radon) are elements notorious for not being very reactive- they have a full set of octet electrons, meaning they do not need to acquire a charge to become stable. For this reason they are commonly used to provide an inert atmosphere when air-sensitive chemical synthesis is done.

However, in 1962, chemist Neil Bartlett was successful in preparing the world’s first noble gas compound by combining xenon gas with platinum hexafluoride to obtain what had been proposed as Xe[PtF6], but has subsequently been proved to be a mxture of similar compounds.

I accredit the scientist Howard Claasen with the discovery of the first noble gas compound, because he was actually able to characterize what he synthesized. Claasen combined xenon and fluorine gas and exposed them to high temperatures to form XeF4- a colorless crystalline solid.

Other compounds of noble gasses have been made, many of them being hydrides or fluorides and some, especially those containing xenon which are possible to produce on a commercial scale can be used as extremely vauable fluorinating and oxidizing agents.

These pigs spend their life glowing in Taiwan.

This entry is particularly important, The discovery of the GFP won scientists Martin Chalfie, Osamu Shimomura, and Roger Tsien the 2008 Nobel Prize in Chemistry.

A protein isolated from jellyfish known as the GFP (green fluorescent protein) has the ability to make a variety of organisms glow when its nucleotide sequence is cloned and expressed. It’s mechanism of action is particularly interesting- GFP fluoresces when another related protein (aequorin) binds to calcium ions. Aequorin on its own fluoresces a blue color, but a transfer of light energy to the GFP shifts the fluorescence to produce a green color. Scientists have been able to modify the gene that expresses GFP to change the chromophore, producing proteins that glow a wide variety of colors. To observe their expression, the nucleotide sequence for the GFP has been cloned in many animals with the most peculiar being several green fluorescing pigs bred in Taiwan.

Mice and Zebrafish (a popular aquarium fish) have been bred so they express the GFP nucleotide sequence and are available at pet stores. They probably don’t live long, as I would imagine that there are probably some serious side-effects to possessing the ability to continuously glow. I also imagine they look pretty creepy. I certainly wouldn’t want to keep one in my home or I might convince myself that I was living within close proximity to Chernobyl.

A colony of this fungus residing in the Malheur National Forest in Oregon is believed to be the world’s largest organism. John Cage would be proud.

If classified as one single organism, a colony of the fungus Armillaria ostoye found in an Oregon forest would be considered the largest living thing on earth. The entire fungus spans 2200 acres and is believed to be around 2400 years old. This particular fungus is a nuisance to loggers, as its mycelium infects the wood of both hardwood and conifer trees.

Lucky for us, it’s edible although I’m not sure of how good it tastes.

A small piece of thulium metal

Aside from research usage, the element thulium has literally no commercial applications although it does possess some special properties that could be exploited in order to create efficient lasers and superconductors. Thulium is a rare-earth element, more precisely a lanthanide metal, meaning it occupies the f-block on the periodic table- an area ignored by many chemists for its lack of interesting chemical behavior. physicists, however, do have regard for these elements because many of them have remarkable magnetic properties, one of the most notable being neodymium, compounded with iron and boron for use in rare earth magnets and now commonly used for thousands of commercial applications. Interestingly enough, thulium itself has some very interesting magnetic properties- it displays ferromagnetic, antiferromagnetic, and paramagnetic ordering at different temperatures- properties typical of lanthanides.

Thulium is an uncommon element and is present in very minute amounts in rare earth minerals such as monazite (rare earth phosphate) and parisite (rare earth carbonate). Monazite is typically mined from sand deposits, where an extraction of this ore mineral is performed using density separative techniques. Since thulium is so similar in chemical behavior to the other rare earths, it is notoriously difficult to separate although new techniques have been developed to lower the cost of its extraction and refining. Thulium oxide produced in the refining process can be reduced to the element through a reduction with calcium metal.

Personally, I think people need to be more affectionate towards our trivalent lanthanide friend. There’s not enough love in the world of chemists for the obscure elements. Thulium, you can be my friend if you want to. I think you’re cool.

Thorny-headed worms infecting the gut of a bluefish. Gross!

Parasitic thorny-headed worms (phylum Acanthocephala) posess the unique ability to control the behavior of their host- the amphipod Gammarus lacustris by releasing serotonin- an important mood-affecting neurotransmitter. Excess serotonin affects amphipods by eliminating their photophobic behavior- these minute crustaceans will typically hide to avoid predation by marine birds. When excess serotonin is relaesed into the amphipod, this aversion to light is lost and they will often swim around in open water making them easy prey for the birds (notably ducks) which act as the secondary host for the parasite. Upon ingestion by a seabird, the thorny-headed worm enters its infective stage, known as a cystacanth, where it inhabits its gut, mates, and releases embryos that exit through the bird’s feces.

This is really a remarkable adaptation- not only do these parasites have an extremely complex lifecycle involving two hosts, they have the peculiar ability to modify the behavior of the intermediate host! Let’s just be glad that they don’t infect humans (or have been genetically modified to do so) or zombies could be a reality! Additionally, these things are really gross looking. A lot of parasites aren’t exactly cute and cuddly and these are especially nasty-looking little guys resembling a cross between a butterfly pupa and a maggot, but they’re still pretty cool albeit extremely disgusting.