Your Wikipedia page references a paper in footnote 21 which says:
> "In developing nations, however, 70–90% of vitamin A is obtained from provitamin A carotenoids in plant foods"
and
> "Whereas retinoic acid can be produced from excentric cleavage of β-carotene in humans (31), it is generally considered a minor contributor to circulating concentrations, at least in normal, healthy persons"
Google tells me that "Two pathways have been suggested for the conversion of carotenoids to vitamin A in mammals, central cleavage and excentric cleavage".
Carotene conversion cannot both be "a minor contributor" to body levels of Vitamin A and also the main way billions of people get Vitamin A. So my guess is the Wikipedia page has mistakenly taken 'excentric cleavage' to be the only conversion method. Still, ignoring carotenes entirely, the referenced paper also says:
> "observational studies suggest that more than 75% of people may be routinely ingesting more than the recommended dietary allowance (RDA) for vitamin A"
> "Dietary vitamin A is obtained from preformed vitamin A (ie, retinyl esters from animal foods, fortified foods, and pharmaceutical supplements) as well as from provitamin A carotenoids from plant sources. Preformed vitamin A is efficiently absorbed and utilized by humans at absorption rates of 70–90%. Up to 75% of dietary vitamin A in Europe, the United States, and other industrialized nations is preformed vitamin A (1, 2), which is largely derived from multivitamins, fish liver oil, and the fortification of foods such as milk, butter, margarine, breakfast cereals, and some snack foods. In developing nations, however, 70–90% of vitamin A is obtained from provitamin A carotenoids in plant foods. These are absorbed much less efficiently, at rates of 20–50%, depending on each person’s vitamin A status and other dietary and nondietary factors (3, 4). The cleavage of provitamin A carotenoids to retinal is a highly regulated step, and vitamin A toxicity from provitamin A sources is largely impossible. In contrast, absorption and hepatic storage of preformed vitamin A occur very efficiently until a pathologic condition develops."
Indeed, but they neither explain nor cite what they mean for it to be "highly regulated" or how/why that means toxicity is largely impossible.
If you take "the cleavage of provitamin A carotenoids" and Ctrl+F for 'cleavage' or 'carotene' in that paper, the only other mentions are this:
> "An acute elevation of retinoids other than retinyl esters—eg, retinoic acid—occurs after the ingestion of a large amount of vitamin A, possibly because the intestinal absorptive capacity is overwhelmed, which leads to the oxidation of retinol to retinoic acid by the intestinal enterocytes (30) and to the rapid formation of retinoic acid from retinol in certain cells (5). Whereas retinoic acid can be produced from excentric cleavage of β-carotene in humans (31), it is generally considered a minor contributor to circulating concentrations, at least in normal, healthy persons."
That is, they only seem to be talking about excentric cleavage and not central cleavage. My limited understanding is that beta-carotene is roughly two retinoic acid molecules chained together, and cleaving them in half is what makes two retinoic acid molecules, and that non-central-cleaving would be different. See skeletal formula on right for these two pages:
(You can also wonder if beta carotene can produce 90% of circulating vitamin A in developing countries, whether getting lots of beta carotene in developed countries can raise the base level in the body, which then leads to easier overdose from preformed vitamin A)
Where can I get cheap recycled lead acid batteries?
I like them more the li-ion because they’re more forgiving to temperature changes and have a much lower chance of catching on fire
The recycling process isn’t direct battery-to-battery. The lead from old batteries is removed, purified, dried into ingots, then sold back to battery manufacturers to make new batteries. In other words, it’s likely that every lead acid battery you buy is made from recycled batteries.
The argument is not esoteric. An Apple employee working on a reverse engineered GPU driver might (intentionally or not) incorporate internal knowledge that they are contractually obligated to keep secret or write an implementation that is too close to proprietary code they had access to, to the point that it could be argued that it is a derived work.
This sort of thing has always been a concern for projects that re-implement some existing piece of software, e.g. there were concerns early on during development of the GNU project about people contributing after having been exposed to Unix source code. Similarly, it is an ongoing concern for the Wine project[1], as well as ReactOS. The later even had a code freeze and internal audit in 2006, after allegations came forward that code had been derived from disassembled Windows binaries[2].
Exactly! That’s why companies create a clone every time they hire someone, put a clone into vat, and upon person quitting, the person is disposed of and the clone is sent to his family to take upon his role, without leaking company’s internal knowledge.
I learned about this concept in college macroeconomics. I asked this exact question and the TA said “yeah I guess repaying debt is like destroying money” as if they had never thought of that before. The idea of lending money increasing the money supply is definitionally true.
Yes, the government doesn’t have a checking account. When it spends money, that money is created and its balance sheet grows. When it receives taxes the balance sheet shrinks as the money is destroyed. If there’s a gap it gets filled by issuing bonds. Thats the national debt. These are conventions, not absolute rules, so governments can go rogue but it doesn’t end well
> when debt is wiped out through bankruptcy that inflation remains
Bankruptcy is deflationary. The same way credit creation makes money bankruptcy (and any other reduction of debt, including through repayment) destroys it. It's why financial crises were often followed by deflation in gold-based economies.
It's a grovel-for-investor-dollars site that we've long pretended is for serious technical discussion. Comments should always be filtered through that lens.
Not sure if you're joking, but I remember noticing the same thing last time I spent time there (2017). Lumber yards tend to have a lot of lumber. It's kind of like when you drive by a feed lot and they have an implausible number of cows (the ones over in imperial valley amazed me). Also there's always tankers by my house in Manhattan Beach. These anecdotes are not economic indicators.
Idk, I’ve had bad handwriting my entire childhood and I still have bad handwriting now as an adult. I’ve (somewhat jokingly) announced that I am “illegible”. It isn’t a detriment to my day to day activities at all, because I can type sufficiently well
You are not required to present an annoying banner to the user. You could simply honor user-agents' DO NOT TRACK header and silently avoid setting tracking cookies and that would comply with the law.
According to the rules, accepting or refusing cookies should be equally difficult. Making them both difficult makes people not use your site, so the incentive should be to make both options easy if you follow the rules.
Malicious compliance is to make cookie acceptance much easier than refusal. Lack of oversight doesn’t punish this. Now, the incentive is to make life hard for people who decline cookies. That results in more annoying pop-ups.
also, session cookies for eg login and error tracing etc dont actually need a banner. you only need to use it if youre participating in the internet stalking behaviour by integrating eg google analytics and similar integrations
From Wikipedia
https://en.wikipedia.org/wiki/Hypervitaminosis_A
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