There are many other intolerances, e.g. coeliac disease and the many different kinds of food allergies.
Besides these cases, which are obvious due to immediate harm, and which are the reason for laws about food labeling that mentions lactose, gluten and various allergens, there is a lot of variability between humans in the efficiency of digesting various foods and in the capacity of absorption for various nutrients.
Some people are able to eat pretty much anything, while others are aware that they do not feel well after eating certain things, so they avoid them.
The most likely hypothesis about how humans have become the most efficient hunters of the planet does not pass through catching insects and very small animals, but through eating the remains of the big prey killed by carnivores.
There are various bits of evidence for this, like the higher stomach acidity of humans, which resembles that of carrion eaters, like hyenas.
It is plausible that the ability to throw sticks and stones was used initially for scaring other predators and make them abandon their prey, and only later, after hundreds of thousands of years of evolution, it became accurate enough to be usable for hunting living animals.
The ability to use stones to break the bones and eat the parts inaccessible for the carnivores who had killed the prey, i.e. marrow and brain, which are rich in hard to get nutrients, e.g. omega-3 fatty acids, is also presumed to have played an important role in the development of a bigger and bigger brain.
It is likely that the gangs of humans acted in a very similar way with the packs of hyenas, which acquire much of their food by scaring away from their prey the other predators, e.g. cheetahs, wild dogs, leopards and even lions. Moreover, similarly to humans, the most important ability of hyenas is not speed, but endurance when pursuing a possible prey that is tired or weakened, e.g. by wounds. While hyenas rely on their big teeth to chase the other predators, humans have relied on their ability to throw things at a distance, for the same purpose. While humans are quite bad at running, jumping, climbing or swimming, in comparison with most mammals, their throwing ability is unmatched by any other animal.
The "algal" omega-3 is not extracted from any algae, but it is extracted from certain cultivated strains of a fungus-like organism, Schizochytrium.
The cultivated strains have been selected and/or genetically engineered to have enhanced production of certain long-chain omega-3 fatty acids.
The composition of an "algal" oil ("algal" is the adjective derived from "alga", "algae" is the plural of "alga") depends on the particular strain that the vendor has used in production.
The first cultivated strains produced only DHA, but in recent years most vendors use strains that allow them to sell oil that has a mixture 2:1 of DHA and EPA, with minor quantities of other long-chain omega-3 fatty acids.
I do not think that growing is difficult, but extracting the oil from it in such a way that it will have a correct composition is likely to be impossible without complex chemical equipment.
For growing it would be difficult to obtain a good strain. The strains used by commercial producers were originally isolated from some mangrove forests or other such places on sea shores, but then they have passed through years of selection and/or gene manipulation. Even when a good strain would be available, a culture that is grown in less controlled conditions could be susceptible to being wiped out by a disease, I have no idea.
In any case, I think the difficulty is in the oil extraction, not in the culture. In industrial conditions the extraction could be made with supercritical carbon dioxide, for maximum cleanness of the extracted oil, but that would not be feasible at home. Using an organic solvent, like hexane, might be possible at home, but that would be dangerous and there is the risk of contamination of the edible oil with solvent residues.
Accurate chemical analysis of the oil would be needed, to determine the fatty acid profile and validate the extraction method.
I cannot read the whole article, but the abstract says nothing about ALA.
The abstract only partitions the omega-3 acids in DHA and non-DHA.
While non-DHA includes ALA, without any concrete evidence that ALA has some direct role, it is more likely that the correlation seen with non-DHA refers not to ALA, but to the other long-chain omega-3 fatty acids besides DHA.
Humans can elongate ALA into useful long-chain acids, but the efficiency of this is typically lower in males than in females and lower in old people than in young people. Usually pregnant women have the best conversion efficiency.
Unless you monitor your blood composition, you cannot know if eating ALA (e.g. flax seeds or oil, or walnuts) can be sufficient for you. If you are an older male, it is very likely that eating ALA cannot be enough for avoiding deficiency.
Schizochytrium oil with DHA and EPA, which is sold as "algal" omega-3, for a lack of a correct word that could be understood by the general population (Schizochytrium is not an alga), is very good and no fish are killed for it.
Nevertheless, it remains at least 3 times more expensive than a fish oil, e.g. cod liver oil (I mean price per content of omega-3 fatty acids, not per volume; when not diluted to fool the customers, "algal" oil has a double concentration in comparison with fish oil, i.e. 5 mL of "algal" oil are equivalent with 10 mL of fish oil).
Taking daily a decent dose of "algal" oil can be more expensive than the daily protein intake required by a human, if that is taken from cheap sources (e.g. legumes and chicken meat). Allocating a major part of the budget for food to a supplement taken in minute quantities seems excessive.
I am not aware of any serious reason for the high cost of "algal" oil. A decade ago, it was much more expensive, e.g. 8 times or more in comparison with cod liver oil. Then the price has dropped to 3 times, and then it has diminished no more, remaining at 3 times for 5 years or more.
I believe that it should be possible to further reduce the cost of "algal" oil to make it an acceptable substitute for fish oil, but it seems that the producers are content with their niche market of rich vegans and they do not make any effort to reduce the cost in order to enlarge their market.
I have taken occasionally "algal" oil, to test it, but as long as it remains a luxury food I cannot use it to replace the cod liver oil that I am taking regularly, despite desiring to do so.
I think that it is a health tax, as many things are. For what it's worth, it costs me 50 cents a day. I'm not sure what semantics about it not being a "true" algae has to do with anything, though. If it's a protist or an algae, I'm not sure what that information does other than muddy the waters for people forming an opinion on non-animal based omegas.
If you consume "algal" oil of 50 cents per day, that must be some kind of capsule with a small amount of oil, e.g. a few hundred mg of DHA+EPA.
This is much better than nothing, but it is far from a daily intake comparable to that of the populations who live in places with access to cheap sea fish, where such fish are a significant fraction of their food (e.g. Japan).
If your target is to match the diet of such populations, that means e.g. 5 mL per day of non-diluted "algal" oil, i.e. a teaspoon of such oil (or 10 mL of fish oil), which contains around 2 grams of long-chain omega-3 fatty acids.
That would be much more expensive when using "algal" oil, at least judging after the prices seen e.g. on Amazon.
In order to not scare the customers, many sources of "algal" oil have a similar price with fish oil, but only because they contain much less omega-3 fatty acids per capsule. If you read the fine print, then you discover the true price ratio.
It is impossible for sodium-ion batteries to reach the same energy density as the best lithium-ion batteries.
So lithium-ion batteries will never be replaced in smartphones or laptops by sodium-ion batteries.
But there are plenty of applications where the energy density of sodium-ion batteries is sufficient. Eventually sodium-ion batteries will be much cheaper and this is why they will replace lithium-ion batteries in all cheap cars and for most stationary energy storage (except when lower auto-discharge is desired).
Sodium has greater density than lithium, while most other materials used in a battery have similar densities regardless if sodium or lithium is used, so if a Na-ion battery and a LFP battery have about the same mass and stored energy, it is likely that the sodium-ion battery has a smaller volume.
that doesn't check out, capacity depends on surface area, if the element that is on the surface is heavier then, all other things equal, the battery will be heavier for same kWh.
Sodium would need to be more efficient to be lighter, which it isn't
The maximum deliverable power depends on electrode area, through the maximum current density.
The capacity of storing energy does not depend at all on area, but only on the mass of sodium contained in the battery and on the efficiency of using it (i.e. between full discharge and full charge not 100% of the sodium or lithium is cycled between the 2 oxidation states, but a fraction, e.g. 90%).
Any battery has both an energy density and a power density, which are weakly correlated and the correlation may have opposite signs, i.e. for some batteries it may be possible to increase the power density if the energy density is lowered and vice-versa.
For a given stored energy in kWh, the required mass of sodium is several times greater than the corresponding mass of lithium, by a factor that is the product of the atomic mass ratio with the ratio between the battery voltages. The voltages are similar, with a slight advantage for sodium, so the required mass of sodium is about 3 times the corresponding mass of lithium.
If the complete batteries have about the same mass, that means that other components of the sodium-ion battery are smaller and/or lighter.
I have no idea about the characteristics of these new sodium-ion batteries, but there is a great likelihood that they auto-discharge much faster than LFP batteries.
This means that if you do not use the car for some time, you may need to recharge it before you can use it again. This may be a problem if the car is left far from a charger.
Even if the degradation of the user interfaces is noticed especially by older people, I doubt that this has anything to do with them being old and I believe that it is caused only by them being more experienced, i.e. having seen more alternatives for user interfaces.
For several decades, I have used hundreds of different computers, from IBM mainframes, DEC minicomputers and early PCs with Intel 8080 or Motorola MC6800 until the latest computers with AMD Zen 5 or Intel Arrow Lake. I have used a variety of operating systems and user interfaces.
During the first decades, there has been a continuous and obvious improvement in user interfaces, so I never had any hesitation to switch to a new program with a completely different user interface for the same application, even every year or every few months, whenever such a change resulted in better results and productivity.
Nevertheless, an optimum seems to have been reached around 20 years ago, and since then more often than not I see only worse interfaces that make harder to do what was simpler previously, so there is no incentive for an "upgrade".
Therefore I indeed customize my GUIs in Linux to a mode that resembles much more older Windows or MacOS than their recent versions and which prioritizes instant responses and minimum distractions over the coolest look.
In the rare occasions when I find a program that does something in a better way than what I am using, I still switch immediately to it, no matter how different it may be in comparison with what I am familiar, so conservatism has nothing to do with preferring the older GUIs.
> Nevertheless, an optimum seems to have been reached around 20 years ago, and since then more often than not I see only worse interfaces that make harder
A consequence of having "UI designers" paid on salary instead of individual contract jobs that expire when the specific fix is complete. In order to preserve their continuing salary, the UI designers have to continue making changes for changes sake (so that the accounting dept. does not begin asking: "why are we paying salary for all these UI designers if they are not creating any output"). So combining reaching an optimum 20 years ago with the fact that the UI designers must make changes for the sake of change, results in the changes being sub-optimal.
> Nevertheless, an optimum seems to have been reached around 20 years ago, and since then more often than not I see only worse interfaces that make harder to do what was simpler previously, so there is no incentive for an "upgrade".
“I've come up with a set of rules that describe our reactions to technologies:
1. Anything that is in the world when you’re born is normal and ordinary and is just a natural part of the way the world works.
2. Anything that's invented between when you’re fifteen and thirty-five is new and exciting and revolutionary and you can probably get a career in it.
3. Anything invented after you're thirty-five is against the natural order of things.”
Alpha Centauri is a triple star, even if it is not the kind of three body system depicted in that story (mainly because one of the 3 stars is much smaller than the other 2, so it orbits stably around them like a very big and distant planet).
While the triple star Alpha Centauri does not have mass ratios between its stars that are compatible with the story plot, I think that ignoring this technical detail is a much less serious plot hole than those of the majority of the non-fantastic Hollywood movies, which are supposed to happen in the real world, but they still contain a lot of impossible actions.
Proxima orbits at a great distance from the inner pair of stars, around their center of mass. Proxima is also a small red dwarf star. This layout had to have been well-known by the time the book was written.
This is perhaps similar to the pursuit of "unobtainium" in Avatar.
Besides these cases, which are obvious due to immediate harm, and which are the reason for laws about food labeling that mentions lactose, gluten and various allergens, there is a lot of variability between humans in the efficiency of digesting various foods and in the capacity of absorption for various nutrients.
Some people are able to eat pretty much anything, while others are aware that they do not feel well after eating certain things, so they avoid them.
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