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During the Bubonic Plague, doctors wore these bird-like masks to avoid becoming sick. They would fill the beaks with spices and rose petals, so they wouldn’t have to smell the rotting bodies. 

A theory during the Bubonic Plague was that the plague was caused by evil spirits. To scare the spirits away, the masks were intentionally designed to be creepy. 

Mission fucking accomplished

Okay so I love this but it doesn’t cover the half of why the design is awesome and actually borders on making sense.

It wasn’t just that they didn’t want to smell the infected and dead, they thought it was crucial to protecting themselves. They had no way of knowing about what actually caused the plague, and so one of the other theories was that the smell of the infected all by itself was evil and could transmit the plague. So not only would they fill their masks with aromatic herbs and flowers, they would also burn fires in public areas, so that the smell of the smoke would “clear the air”. This all related to the miasma theory of contagion, which was one of the major theories out there until the 19th century. And it makes sense, in a way. Plague victims smelled awful, and there’s a general correlation between horrible septic smells and getting horribly sick if you’re around what causes them for too long.

You can see now that we’ve got two different theories as to what caused the plague that were worked into the design. That’s because the whole thing was an attempt by the doctors to cover as many bases as they could think of, and we’re still not done.

The glass eyepieces. They were either darkened or red, not something you generally want to have to contend with when examining patients. But the plague might be spread by eye contact via the evil eye, so best to ward that off too.

The illustration shows a doctor holding a stick. This was an examination tool, that helped the doctors keep some distance between themselves and the infected. They already had gloves on, but the extra level of separation was apparently deemed necessary. You could even take a pulse with it. Or keep people the fuck away from you, which was apparently a documented use.

Finally, the robe. It’s not just to look fancy, the cloth was waxed, as were all of the rest of their clothes. What’s one of the properties of wax? Water-based fluids aren’t absorbed by it. This was the closest you could get to a sterile, fully protecting garment back then. Because at least one person along the line was smart enough to think “Gee, I’d really rather not have the stuff coming out of those weeping sores anywhere on my person”.

So between all of these there’s a real sense that a lot of real thought was put into making sure the doctors were protected, even if they couldn’t exactly be sure from what. They worked with what information they had. And frankly, it’s a great design given what was available! You limit exposure to aspirated liquids, limit exposure to contaminated liquids already present, you limit contact with the infected. You also don’t give fleas any really good place to hop onto. That’s actually useful.

Beyond that, there were contracts the doctors would sign before they even got near a patient. They were to be under quarantine themselves, they wouldn’t treat patients without a custodian monitoring them and helping when something had to be physically contacted, and they would not treat non-plague patients for the duration. There was an actual system in place by the time the plague doctors really became a thing to make sure they didn’t infect anyone either.

These guys were the product of the scientific process at work, and the scientific process made a bitchin’ proto-hazmat suit. And containment protocols!

reblogging for the sweet history lesson

sciencesoup:

Translation

In the process of transcription, an enzyme called RNA polymerase painstakingly copies a strand of DNA, and sends the freshly copied messenger out into the world, ready to tell ribosomes how to synthesise proteins.

Before we get onto how this is done, let’s take a look at what ribosomes are. The ribosome is a protein-making machine that’s actually made of RNA. It has two parts or subunits that bind on either side of the incoming mRNA: the small subunit reads the RNA, and the large subunit joins amino acids together to form a polypeptide chain.

But there’s a catch. Ribosomes don’t speak the same language as DNA does. If they were given the raw blueprints, it’d be like you opening up a box from IKEA and finding an instruction booklet written entirely in Swedish, without any pictures to stop you from attaching table legs upside down. Of course, if you were in that situation, you’d go to Google Translate to help get the information across—and ribosomes actually do the same thing. Well, almost.

The cell has to somehow interpret the genetic message from the sequences of nucleotides from the mRNA, and translate them into the amino acid sequence of a polypeptide. Our interpreter—the cell’s equivalent of Google Translate—is another handy RNA molecule called Transfer RNA (tRNA), which floats around in the cytoplasm. In basic terms, its function is to read the message on the mRNA molecule, then goes and fetches the right amino acids and gives them to the ribosome to attach into a polypeptide chain. It does this with the help of an enzyme called amino acetyl tRNA synthase, which helps match up the amino acid to the tRNA. There are twenty different types of synthase, one for each amino acid.

Basically, it turns the language of nucleic acids into the language of proteins.

But how does the tRNA know how to read the mRNA molecule?

Well, the sequence of bases on an mRNA molecule are arranged in a specific way—in a series of non-overlapping codons. A codon is a group of three nitrogenous bases that code for a specific amino acid. The code CUU (cytosine-uracil-uracil), for example, codes for the amino acid leucine.

image

There are different kinds of tRNA that bind to a specific amino acid. Each one has a specific three-nucleotide sequence called an anti-codon that matches up with the complementary mRNA codon.

Some codons don’t code for an amino acid but rather act as a stop or go signal. See, if you’ve got a bunch of bases that have to be read in particular groups, you want to make sure that your tRNA starts at the right spot. Otherwise, the reading frame gets shifted one or two bases over, and suddenly your tRNA is fetching the wrong amino acids and your protein is a complete disaster. There are three different “stop” codons (UAA, UAG, and UGA) and one “start” codon (AUG). These tell the tRNA where to start reading and where to stop reading.

However, as you may have noticed from the table above, there isn’t just one codon for each amino acid. There are 61 different ways you can arrange four nucleotides into groups of three, so there are 61 codons. This means that some codons code for more than one amino acid. As you may also have noticed, the codons that code for the same amino acid all have the same first two nucleotides—it’s only the third nucleotide that changes.

This is a really important point. It means that the third nucleotide in a codon isn’t really that important. Most of the time, you could change that nucleotide and the same amino acid will still be produced. If any of the other nucleotides were changed, this could fundamentally alter what the codon codes for—another, incorrect amino acid would then be added to the polypeptide chain, and it could have a huge effect on the function of the chain. This is a mutation. But if the mutation occurs in the third nucleotide, chances are, everything will be fine.

On that note, another important thing—there isn’t one tRNA molecule for each codon. There are only 45 different tRNAs, and some can bind to more than one codon. Again, this is because the third nucleotide is the most flexible, and less important.

Next: a look at the steps of protein synthesis.

Body images sourced from Wikimedia Commons

Further resources: Translation

Deep Water

science:

In March, a study reported an interesting finding: inside a diamond brought up from the depths of the Earth by a volcano in Brazil, a small piece of the mineral ringwoodite was found, and about one percent of its mass was accounted for by water bound in solid form inside the crystalline structure. Now, a study bringing together evidence from an array of seismic sensors across the United States and laboratory work simulating the conditions of the transition zone between the Earth’s upper and lower mantle, around 400-700 kilometers’ depth, suggests that this was no anomaly. The lab work suggests that, under the conditions of extreme pressure in the transition zone, ringwoodite can soak up more than one percent of its mass in water. When some of this ringwoodite is pushed down further into the lower mantle, it gets crushed into a different kind of mineral that can’t hold water. As a result, the rock “sweats” water, which is trapped in pockets deep beneath the surface.

The observations of seismic waves found changes in wave velocity consistent with such subterranean water. If 1% of the rock in the transition zone is water, that would be the equivalent of three times the mass of water in all of the oceans on the surface.

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