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Archaeal ribosomes are like eukaryotic not bacterial forms

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Jenny
1379116.  Sun Apr 11, 2021 9:34 am Reply with quote

Cele I remember that when my first husband went to university in 1966 to study Chemistry, one of the first things he was told was to forget everything he'd learned at A level. Sounds as if it was similar in your field? Or did that happen to be a particularly turbulent time in the world of science studies?

 
Celebaelin
1379142.  Sun Apr 11, 2021 12:28 pm Reply with quote

Without knowing what your late husband had been told I can't really comment but the stuff I'm talking about wasn't even touched on at school when I was doing A Levels and some of it (e.g. the bit that's actually correct up to a point) wasn't yet taught at Masters level (and probably still isn't).

I was reading around the work to a fairly wide extent when studying for my masters and the bit I'm referring to was covered to a greater or lesser degree of accuracy in all the non-standard texts related to one particular aspect of the course and even in the standard texts in a mystifyingly oblique way (such that you could miss it if you weren't actively looking for it).

In the end to stand a chance of understanding the derivation I had to hunt down the original 1935 paper - which was no easy task when 50% of the sources who cite the reference actually get the citation wrong. Not only that but initially I had to re-order it from the library - they claimed they'd put it in my pigeon hole but if they did some p.o.s. nicked it before I picked it up; eventually I did get hold of a copy however.

Cutting edge stuff that was over 60 years old at that point!

 
Dix
1379149.  Sun Apr 11, 2021 1:20 pm Reply with quote

I think it' s fairly common that the introduction level of "stuff" uses simplified explanations that aren't the whole truth by quite some way.
A relation who studied chemistry at uni once said to me that the courses were broadly looking at the same questions as always, it's just that the answers got more and more complicated.

 
Celebaelin
1379260.  Mon Apr 12, 2021 12:47 pm Reply with quote

That's also in many ways how science develops - that is as long as the initial premise is accepted and assuming subsequent refinements are necessary.

In the case of Higbie, Dankwerts etc it strikes me that the data from actual stirred tanks will effect results depending on the ratio of the volume of the tank to the internal surfaces (both static material size and effective surface due to impeller speed through the liquid). As far as I can tell from what I can find on the web this hasn't been looked at yet.

 
suze
1379289.  Mon Apr 12, 2021 4:45 pm Reply with quote

Celebaelin wrote:
In the case of Higbie, Dankwerts etc it strikes me that the data from actual stirred tanks will effect results depending on the ratio of the volume of the tank to the internal surfaces (both static material size and effective surface due to impeller speed through the liquid). As far as I can tell from what I can find on the web this hasn't been looked at yet.


Then arse into gear, and here lies your next project!

Do a proper literature search, and if this piece of work really hasn't been done then get writing a PhD proposal!

 
Celebaelin
1379295.  Mon Apr 12, 2021 9:27 pm Reply with quote

I can't afford to fund myself through another research degree but if it is indeed a thus far unconsidered idea it would be more like Post Doctoral research in search of a specific proposal with a testable hypothesis and/or equation (and hopefully a central thrust which would still be informative in the event of a negative result). A PhD by publication along the way would be my preference.

UCL (again) would be the ideal place and much as it is a great environment to work in (i.e. not a campus University) London as a whole is horribly expensive; when HS2 is in place it will make the commute itself totally doable though - NEC to Euston in a projected 38 mins.

I should clarify my meaning regarding that previous post as I edited it and it got a bit jumbled up.

Celebaelin almost wrote:
In the case of Higbie, Dankwerts etc it strikes me that the results from actual stirred tanks will be affected by the ratio of the volume of the tank to the internal surfaces (both static, material size and effects due to the rate of impeller movement through the liquid and eg drive shaft rotation). As far as I can tell from what I can find on the web this hasn't been looked at yet.

 
Celebaelin
1379316.  Tue Apr 13, 2021 6:40 am Reply with quote

I've actually been thinking about this and a more global approach to mass transfer is needed here than just examining the contribution of the boundary effects between bulk fluid and vessel walls etc.

You'd have to look at mixing anyway (KLA will vary with impeller speed) and the way I'd propose to do that would open up the possibility of looking at helical cooling coil function as well; I nearly went into more detail but it'd be copyright of QI if I did so I won't.


Last edited by Celebaelin on Tue Apr 13, 2021 1:51 pm; edited 1 time in total

 
PDR
1379320.  Tue Apr 13, 2021 7:12 am Reply with quote

suze wrote:
But for a much bigger thing, the Norsemen were there five hundred years before him. When I was in school that was treated as fantasy fiction. It gets slightly more coverage by now, but it's still taught very much as a footnote to Columbus - when in fact, it ought to be the story and Columbus the footnote.


If we made that adjustment then presumably we would have to re-name "Columbia" to "Norsia". That would mean that the seat of the federal government was in the District of Norsia, which would explain a lot.

PDR

 
PDR
1379321.  Tue Apr 13, 2021 7:24 am Reply with quote

Celebaelin wrote:
Another one in biochemistry is Michaelis-Menten Enzyme Kinetics.

Not merely out of date but WRONG. So very, very wrong.


The same could be said of the "different path distance" explanation of wing lift, which has been out of date for over a hundred years and conflicts with (or fails to predict/explain) so many measurable, observable phenomena. It fails to describe drag in any manner which produces meaningful calculations, it also denies the Kutta condition even though it is directly and repeatably observable in a wind tunnel, and it fails to explain why lift increases linearly with angle of attack (a fundamental feature of aerodynamics without which aeroplanes wouldn't fly).

Another feature taught in history classes is that many of the first settlers headed for the New World in search f religious freedom, when the reality is precisely the opposite. They actually headed west to escape the depravity (in their view) of growing secularism and token religious observance with the intention of establishing "proper" strict, god-fearing theocracies.

Much of what is taught in schools doesn't really stand scrutiny. Should we blame the teachers?

<runs away, cackling manically>

PDR

 
PDR
1379324.  Tue Apr 13, 2021 7:48 am Reply with quote

suze wrote:
But for a much bigger thing, the Norsemen were there five hundred years before him. When I was in school that was treated as fantasy fiction.


This is an extremely sensitive area, because some archaeological studies have found evidence that may even support a suggestion that the *original* pre- and proto-human inhabitation of north america came from scandinavians who had walked across the ice and/or got there by sea (or possibly even across a land-bridge depending on which dates you want to believe). The same evidence suggests (but doesn't prove) that the ancestors of the current "native americans" came from south america and killed/pushed out the scandi-original communities.

This would be an extremely controversial finding. Even if we assume the scandiwegians wouldn't press a claim for reparations and restitution of their sovereignty in north-east america, such a finding would at a stroke invalidate the claims of the "native americans". And that would remove the justification for special treatment like autonomous reservations, access to federal financial support etc. That's why investigation of historical artefacts in north america often attracts a veritable blitz of litigious estoppelling...

PDR

 
suze
1379343.  Tue Apr 13, 2021 10:12 am Reply with quote

The received wisdom for most of the C20 was that the first human settlement of the American continent happened ~17,000 years ago. Those settlers entered via the Bering Land Bridge from what is now Siberia, and gradually worked their ways east and south. It is usually suggested that it couldn't have been very much earlier because of glaciers which would have prevented much southward progress.

Over the last couple of decades that has been called into question. Almost all of the claims for earlier human habitation are disputed, and some of them look a lot like deliberate falsehoods, but there is some evidence which could be interpreted as indicating a human presence ~35,000 years ago. If it is so - and I'm skeptical - the obvious explanation is that these folks crossed over one glacial cycle earlier.

But as far as I know, there is no serious dispute over the method of entry - the Bering Land Bridge - or the origin of those who made the crossing - Siberia.


To be sure, there are a dozen claims of pre-Norse trips from the rest of the world to America. Chinese in Mexico, West Africans in Mexico, Japanese in Ecuador, Indians (by which I mean people from India) in Guatemala, baseball-playing Irish monks, you name it. None stands up to much scrutiny, and in any case only one is represented as having happened before the crossings of the Bering Land Bridge.


The one is known as the Solutrean Hypothesis, and asserts that people from what are now France and Spain (the Solutrean Culture) went to America across the North Atlantic ~20,000 years ago. You could write a book about it, and another book about why it's highly implausible - and several versions of both of those books exist.

But just two objections to it from me. One, what is known of the Solutreans in Europe of that era suggests that they hadn't invented boats yet. That makes crossing the North Atlantic kinda tricky.

Two, one thing they had invented in Europe was cave painting - and yet they didn't do any in America. In all seriousness, the proponents of the Solutrean Hypothesis explain this by asserting that the people who went to America were outcasts from mainstream society, rejected because they were no good at painting. Of course!

Some - by no means all - of the proponents of the Solutrean Hypothesis are white supremacists. As PDR suggests, if white people from France and Spain had been in America before those pesky "red" people from Siberia, then the latter group couldn't say they were there first.

Just one problem with this. Being white was probably a Scandiwegian innovation, but it didn't happen until ~8,000 years ago. The Solutreans were probably of what we now view as South Asian appearance.

 
Jenny
1379345.  Tue Apr 13, 2021 10:56 am Reply with quote

I'm currently listening on audiobook to Isabelle Wilkerson's book Caste, in which she argues that there was no real concept of race as such being allied to colour of skin before black African slavery as it was practiced from the 17th century onwards in North America. There was certainly slavery, but she argues that this was the first time it was linked to physical appearance. On the other hand, the caste system is long and well established in many cultures, particularly Indian, and she regards slavery and its aftermath including the condition of people of colour in the USA as being essentially part of a caste system.

 
PDR
1379349.  Tue Apr 13, 2021 11:29 am Reply with quote

I remember hearing of a case ("Kennewick Man"?) where an ancient skeleton was found, but the local tribe claimed ownership. The Army was involved for some reason I forget, and they took custody of the skeleton while it went through the courts to determine whether detailed analysis was allowed.

Although it was not disclosed until years later, the local military commander took it upon himself to be "sensitive" to the wishes of the tribe, and allowed them to conduct some ceremonies over the remains. The ceremonies included some sort of reblooding ritual which involved smearing the bones with fresh blood from the tribe. At a later date the court ordered a specific DNA test to be conducted to determine whether there was much connection between the skeleton and the current tribe. Unsurprisingly these tests returned a strong connection, so the court ruled that the skeleton was a tribal elder. The tribe then took it and reburied it in an undisclosed location (even though burial was not a part of their tradition). Of course when it finally came out that the tests were invalid due to contamination with modern blood it was too late, and the tribe claimed no one knew where the body was any more, so that was that.

PDR

 
Leith
1379383.  Tue Apr 13, 2021 6:42 pm Reply with quote

Jenny wrote:
I'm currently listening on audiobook to Isabelle Wilkerson's book Caste, in which she argues that there was no real concept of race as such being allied to colour of skin before black African slavery as it was practiced from the 17th century onwards in North America.

That seems a widely held view now on the origins of harmful perceptions of race in the European diasporas. David Olusoga and Adam Rutherford have written in a similar vein.

Pseudo-scientific philosophies of racial hierarchy emerged during the enlightenment, formulated by the likes of Linneaus, Kant and Voltaire. Although Voltaire, and Kant in his later years, spoke strongly against slavery, their theories of race were seized upon by slavers like Edward Long to justify and promote slavery.

There has always been tribalism, prejudice and fear of the other in human societies, but many historians argue that weaponized forms of society-wide prejudice along racial lines aren't widely seen in the European world prior to their adoption as pro-slavery, and subsequently pro-colonization propaganda. Extreme acts of subjugation require extreme justifications, I suppose.

It's not necessarily unique to European oppression. You see some evidence of racial hierarchies used to justify slavery in the medieval Islamic empires in the writings of Avicenna / Ibn Sina, but it's the European enlightenment version that leaves a visible legacy in the societies of Europe and its former dominions.

 
ABD
1380277.  Mon Apr 26, 2021 4:38 pm Reply with quote

Since this is a chat discussing both archaea and the Norse, I think it's the perfect place to bring up the superphylum Asgard. It includes Heimdalarchaeota, Thorarchaeota, Lokiarchaeota, and Odinarchaeota. I just learned about its existence the other day and was mildly amused for the rest of class.

 

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