Wikipedia:Reference desk/Archives/Science/2023 December 31

= December 31 =

Last year Q - Giant prokaryotes' strangeness
This bacterium and its relative T. namibiensis are truly gigantic - they dwarf many species of Protozoa (such as the Euglena) and invertebrates even though they are not eukaryotic. Obviously, being too large for a bacterium must lead to several problems (e.g the bigger the cell, the smaller the S-to-V ratio, which easily reduce the metabolism rate). However we knew that there are some special structures within the cells of these "giants" that help they overcoming these problems, such as the large aqueous sacs. My question: Is there any limit, theoretically speaking, to the maximum size that a prokaryote can grow, in the case these special structures are taken into account? What is the limit to the maximum size that a "normal" prokaryote (the one that doesn't possess any special structures) can grow? I have thought that in the later case, the limit should be some tens of μm, but I'm not sure. 2402:800:63AD:F268:1576:679F:2D64:9CC7 (talk) 12:09, 31 December 2023 (UTC)


 * According to there is increasing evidence of more prokaryotic compartmentalization and internal structure in at least some prokaryotes (not only Thiomargarita) than once thought. It is difficult to decide when organelles become "special". Here is a discussion of the size range of bacteria, mentioning several whose diameter is larger than some tens of μm.  --Lambiam 16:52, 31 December 2023 (UTC)
 * It is thought that the size limits are not so much physiological but ecological. Prior to the advent of the eukaryotes, there are possible fossils of possible bacteria that are macroscopic. The thinking is that in the absence of competition and predation from eukaryotes (and later, multicellular eukaryotes), bacteria could occupy larger niches. Abductive  (reasoning) 17:31, 31 December 2023 (UTC)
 * See also this science documentary. {The poster formerly known as 87.81.2309.195} 51.198.104.88 (talk) 01:54, 2 January 2024 (UTC)

US metric units
Are there any American websites that, at least consistently, use metric units as first or only units? --40bus (talk) 19:27, 31 December 2023 (UTC)
 * I'm not seeing anything on Google so far that directly answers that question. But it's a fair bet that any site that expects to sell something to Americans would probably have both units. ←Baseball Bugs What's up, Doc? carrots→ 22:42, 31 December 2023 (UTC)
 * Science related sales is a good bet. For most products, MilliporeSigma lists in metric units, and they are an American company. --OuroborosCobra (talk) 23:04, 31 December 2023 (UTC)
 * Mmh.. and is there any need to translate the French "trompe-l'oeil", in American English? No, about-us/life-science says they're at core, a European company. --Askedonty (talk) 00:54, 1 January 2024 (UTC)
 * That's a subsidiary company, and gets into the confusing issue of decades of mergers and such. Our article says it is an American company based out of Massachusetts. But, we then get into the whole history of there having been a Sigma Chemical Company founded in the US, an Aldrich company founded in the US, merging to create Sigma-Aldrich, another company named Millipore founded in the US, a company named Merck founded in Germany, Merck buying out Millipore at some point to make the company EMD Millipore, then Merck Millipore, then that merging with Sigma-Aldrich to become MilliporeSigma, which has been rebranded recently back to Sigma-Aldrich. This all took place over a span of some three centuries (though mostly in the last 70 or so years). That said, while having a parent company in Germany, it is still registered as a US company. Because reasons? --OuroborosCobra (talk) 15:34, 1 January 2024 (UTC)
 * They do not have to be EC compliant regarding all regulations? --Askedonty (talk) 20:14, 1 January 2024 (UTC)
 * ...that's a separate question. I've worked for an American based pharmaceutical that was a small business with no parent company and based entirely out of the United States, and it still followed ICH regulations even though the US is not an ICH member state. Pretty much all relevant job listings in US pharma will list needing an awareness of ICH as well as FDA and cGMP regulations. As for EC, are you referring to something like European Community number? If so, not necessarily. --OuroborosCobra (talk) 20:36, 2 January 2024 (UTC)
 * Although, since chemical drugs (pills) are or were going systematically through the process of milling, why would the pharmaceutical industry have found it had to be worried at complying shifting to mill-i-gram ? --Askedonty (talk) 01:20, 1 January 2024 (UTC)
 * Certainly the US Metric Association website does. --jpgordon&#x1d122;&#x1d106;&#x1D110;&#x1d107; 00:19, 1 January 2024 (UTC)