100 Greatest Discoveries by the Discovery Channel (2004-2005) Updated 2024-12-15 +Created 1970-01-01
Hosted by Bill Nye.
Physics topics:
- Galileo: objects of different masses fall at the same speed, hammer and feather experiment
- Newton: gravity, linking locally observed falls and the movement of celestial bodies
- TODO a few more
- superconductivity, talk only at Fermilab accelerator, no re-enactment even...
- quark, interview with Murray Gell-Mann, mentions it was "an off-beat field, one wasn't encouraged to work on that". High level blablabla obviously.
- fundamental interactions, notably weak interaction and strong interaction, interview with Michio Kaku. When asked "How do we know that the weak force is there?" the answer is: "We observe radioactive decay with a Geiger counter". Oh, come on!
biology topics:
- Leeuwenhoek microscope and the discovery of microorganisms, and how pond water is not dead, but teeming with life. No sample of course.
- 1831 Robert Brown cell nucleus in plants, and later Theodor Schwann in tadpoles. This prepared the path for the idea that "all cells come from other cells", and the there seemed to be an unifying theme to all life: the precursor to DNA discoveries. Re-enactment, yay.
- 1971 Carl Woese and the discovery of archaea
Genetics:
- Mendel. Reenactment.
- 1909 Thomas Hunt Morgan with Drosophila melanogaster. Reenactment. Genes are in Chromosomes. He observed that a trait was linked to sex, and it was already known that sex was related to chromosomes.
- 1935 George Beadle and the one gene one enzyme hypothesis by shooting X-rays at bread mold
- 1942 Barbara McClintock, at Cold Spring Harbor Laboratory
- 1952 Hershey–Chase experiment. Determined that DNA is what transmits genetic information, not protein, by radioactive labelling both protein and DNA in two sets of bacteriophages. They observed that only the DNA radioactive material was passed forward.
- Crick Watson
- messenger RNA, no specific scientist, too many people worked on it, done partially with bacteriophage experiments
- 1968 Nirenberg genetic code
- 1972 Hamilton O. Smith and the discovery of restriction enzymes by observing that they were part of anti bacteriophage immune-system present in bacteria
- alternative splicing
- RNA interference
- Human Genome Project, interview with Craig Venter.
Medicine:
- blood circulation
- anesthesia
- X-ray
- germ theory of disease, with examples from Ignaz Semmelweis and Pasteur
- 1796 Edward Jenner discovery of vaccination by noticing that cowpox cowpox infected subjects were immune
- vitamin by observing scurvy and beriberi in sailors, confirmed by Frederick Gowland Hopkins on mice experiments
- Fleming, Florey and Chain and the discovery of penicillin
- Prontosil
- diabetes and insulin
Good website, with poems in Chinese, pinyin and commented translation. Well done!
100 poems website 100tangpoems.wordpress.com/2023/02/27/pure-and-fair/
100 poems website 100tangpoems.wordpress.com/2023/02/27/pure-and-fair/
As mentioned at hero108.fandom.com/wiki/The_108_Heroes there are only 3 women amongst the 108:
- 59 Hu Sanniang
- 101 Gu Dasao
- 103 Sun Erniang. She's the human flesh mantou lady!
To Ernest Lawrence for the cyclotron.
This website used to allow embedding text messages with OP_RETURN, here's an archive from 2015: web.archive.org/web/20150718052659/http://eternitywall.it/
As of January 2024, it seems to read-only mode, where it simply indexes matching transactions that were made via other means: web.archive.org/web/20230929075331/https://eternitywall.it/
A Reddit announcement from July 2015: www.reddit.com/r/Bitcoin/comments/3dxy9f/eternity_wall_messages_lasting_forever/
There were 3191 hits for the search term:in our data starting with tx a3b3af21514bd79a4cbcac9916a8514636a72d813539192214542fd85247082e (2015-06-24):up to the last entry on tx 28820bc14cf2cfda58ecbc9ac6df3f41a1cb90f4246543f01ba42a5e9dac3cf8 (2023-06-15)no doubt initials of 4 Chinesepeople. A blood brother oath comes to mind, akin to the Oath of the Peach Garden. Will these four be the ones to take down the evil dictator Xi Jinping?
git grep '\bEW 'EW Eternity wall is live
EW May our friendship endure, signed by hg, kty, wjj, and xyz.
The very first message gives away the name of what we assume is a web-based upload system, "EW" being its advertisement signature added to every message.
Running shows that the messages are encoded with OP_RETURN:
bitcoin-cli:bitcoin-core.cli getrawtransaction a3b3af21514bd79a4cbcac9916a8514636a72d813539192214542fd85247082e true "vout": [
{
"value": 0.00000000,
"n": 0,
"scriptPubKey": {
"asm": "OP_RETURN 455720457465726e6974792077616c6c206973206c697665One cool thing we did in this procedure was to use magnetic separation with magnetic beads to further concentrate the DNA: Figure 1. "GE MagRack 6 pipetting.".
The beads are coated to stick to the DNA, which allows us to easily extract the DNA from the rest of the solution. This is cool, but bio people are borderline obsessed by those beads! Go figure!
Then we prepared the DNA for sequencing with the Oxford Nanopore specific part: Oxford Nanopore SQK-LSK109 Ligation Sequencing Kit.
Here some of the steps required a bit more of vortexing for mixing the reagents, and for this we used the VELP Scientifica WIZARD IR Infrared Vortex Mixer which appears to be quicker to use and not as strong as the Vortex Genie 2 previously used to break up the cells:
After all that was done, the DNA of the several 400 ml water bottles and hours of hard purification labour were contained in one single Eppendorf!
Has as a double cover.
NCBI entry: www.ncbi.nlm.nih.gov/gene/945803.
Part of a reaction that produces threonine.
This protein is an enzyme. The UniProt entry clearly shows the chemical reactions that it catalyses. In this case, there are actually two! It can either transforming the metabolite:Also interestingly, we see that both of those reaction require some extra energy to catalyse, one needing adenosine triphosphate and the other nADP+.
- "L-homoserine" into "L-aspartate 4-semialdehyde"
- "L-aspartate" into "4-phospho-L-aspartate"
TODO: any mention of how much faster it makes the reaction, numerically?
Since this is an enzyme, it would also be interesting to have a quick search for it in the KEGG entry starting from the organism: www.genome.jp/pathway/eco01100+M00022 We type in the search bar "thrA", it gives a long list, but the last entry is our "thrA". Selecting it highlights two pathways in the large graph, so we understand that it catalyzes two different reactions, as suggested by the protein name itself (fused blah blah). We can now hover over:Note that common cofactor are omitted, since we've learnt from the UniProt entry that this reaction uses ATP.
- the edge: it shows all the enzymes that catalyze the given reaction. Both edges actually have multiple enzymes, e.g. the L-Homoserine path is also catalyzed by another enzyme called metL.
- the node: they are the metabolites, e.g. one of the paths contains "L-homoserine" on one node and "L-aspartate 4-semialdehyde"
If we can now click on the L-Homoserine edge, it takes us to: www.genome.jp/entry/eco:b0002+eco:b3940. Under "Pathway" we see an interesting looking pathway "Glycine, serine and threonine metabolism": www.genome.jp/pathway/eco00260+b0002 which contains a small manually selected and extremely clearly named subset of the larger graph!
But looking at the bottom of this subgraph (the UI is not great, can't Ctrl+F and enzyme names not shown, but the selected enzyme is slightly highlighted in red because it is in the URL www.genome.jp/pathway/eco00260+b0002 vs www.genome.jp/pathway/eco00260) we clearly see that thrA, thrB and thrC for a sequence that directly transforms "L-aspartate 4-semialdehyde" into "Homoserine" to "O-Phospho-L-homoserine" and finally tothreonine. This makes it crystal clear that they are not just located adjacently in the genome by chance: they are actually functionally related, and likely controlled by the same transcription factor: when you want one of them, you basically always want the three, because you must be are lacking threonine. TODO find transcription factor!
The UniProt entry also shows an interactive browser of the tertiary structure of the protein. We note that there are currently two sources available: X-ray crystallography and AlphaFold. To be honest, the AlphaFold one looks quite off!!!
By inspecting the FASTA for the entire genome, or by using the NCBI open reading frame tool, we see that this gene lies entirely in its own open reading frame, so it is quite boring
From the FASTA we see that the very first three Codons at position 337 arewhere
ATG CGA GTGATG is the start codon, and CGA GTG should be the first two that actually go into the protein:ecocyc.org/gene?orgid=ECOLI&id=ASPKINIHOMOSERDEHYDROGI-MONOMER mentions that the enzime is most active as protein complex with four copies of the same protein:TODO image?
Aspartate kinase I / homoserine dehydrogenase I comprises a dimer of ThrA dimers. Although the dimeric form is catalytically active, the binding equilibrium dramatically favors the tetrameric form. The aspartate kinase and homoserine dehydrogenase activities of each ThrA monomer are catalyzed by independent domains connected by a linker region.
With all this ready, we opened the Nanopore flow cell, which is the 500 dollar consumable piece that goes in the sequencer.
We then had to pipette the final golden Eppendorf into the flow cell. My anxiety levels were going through the roof: Figure 4. "Oxford nanopore MinION flow cell pipette loading.".
At this point bio people start telling lab horror stories of expensive solutions being spilled and people having to recover them from fridge walls, or of how people threw away golden Eppendorfs and had to pick them out of trash bins with hundreds of others looking exactly the same etc. (but also how some discoveries were made like this). This reminded Ciro of: youtu.be/89UNPdNtOoE?t=919 Alfred Maddock's plutonium spill horror story.
Luckily this time, it worked out!
We then just had to connect the MinION to the computer, and wait for 2 days.
During this time, the DNA would be sucked through the pores.
As can be seen from Video 1. "Oxford Nanopore MinION software channels pannel on Mac." the software tells us which pores are still working.
Pores go bad sooner or later randomly, until there are none left, at which point we can stop the process and throw the flow cell away.
48 hours was expected to be a reasonable time until all pores went bad, and so we called it a day, and waited for an email from the PuntSeq team telling us how things went.
We reached a yield of 16 billion base pairs out of the 30Gbp nominal maximum, which the bio people said was not bad.
Their status is a mess as of 2020s, with several systems ongoing. Long live the "original" collegiate university!
Aaron, Ciro Santilli will complete your quest to make eduction free. Just legally this time, with the and with the Creative Commons license you helped to create.
Ciro likes how The Internet's Own Boy (2014) explains how Aaron felt like high school was bullshit, and that he could learn whatever he wanted from books, which is one of Ciro's key feelings.
It also mentions how he was a natural teacher from a very early age.
The degree of some algebraic structure is some parameter that describes the structure. There is no universal definition valid for all structures, it is a per structure type thing.
This is particularly useful when talking about structures with an infinite number of elements, but it is sometimes also used for finite structures.
Examples:
- the dihedral group of degree n acts on n elements, and has order 2n
- the parameter that characterizes the size of the general linear group is called the degree of that group, i.e. the dimension of the underlying matrices
There are unlisted articles, also show them or only show them.