adrian_b

The io_uring interface is preferable to classic syscalls for any kind of syscall that requires the kernel to perform a significant amount of work or to wait for some external events, so a long time could pass until the completion of the work or until the occurrence of the external events, and possibly for some auxiliary syscalls that modify settings relevant to the previous syscalls.

Many of the most important syscalls belong to this class, but most of them already have io_uring alternatives. Many other syscalls are not of this kind, so for them there is no reason to replace the traditional syscall interface.

For the syscalls appropriate for io_uring the essential characteristic is that their completions can occur in a different order than the submissions of their requests, which is why all previous methods of handling them were inefficient, because they required the user program to waste time with superfluous activities, instead of just picking the completion messages from a queue.

Where this out-of-order execution is not needed, invoking the syscalls in the same way as you invoke any user function is fine.

The initial implementation of io_uring lacked the alternatives for many important syscalls, but since then most of the holes have been filled.

Besides more obvious syscalls of the read/write type, which are used for files accessed in the classic way, in order to reach maximum performance with memory-mapped files the old "madvise" syscall must be replaced with IORING_OP_MADVISE, used with Linux-specific advices (MADV_COLD, MADV_PAGEOUT, MADV_POPULATE_READ, MADV_POPULATE_WRITE).

This wave of attacks against refrigerators started in USA with many refrigerators serving the personnel at several military bases, a couple of months ago.

Therefore even the US Army has not been better prepared than supermarket chains.

He bragged about it only after it became impossible to do the same.

They have probably chosen "V" for the English transliteration to avoid being confused with a bio-engineering company.

Laser projectors with light modulators based on nanotech mirrors have already replaced xenon arc lamps in some of their main applications, long ago.

Where you really need white light with a continuous spectrum, there are very few alternatives to arc lamps.

Some time ago there were published some interesting research results, which suggested that it is possible for incandescent lamps to make a comeback, this time at a efficiency comparable with white LEDs. That could be achieved with a carbon filament in a gas mixture that prevents evaporation, where all the inner walls of the lamp are very good mirrors for infrared light, but the front window of the lamp has an optical filter that passes visible light, while reflecting infrared light.

Such an incandescent lamp could have a much better efficiency than an arc lamp, and also a longer life (the very low efficiency of the traditional incandescent lamps is due to most of the energy being lost as infrared light).

It remains to be seen whether that research can lead to commercial products.

The drawings in the article show that the yellow goop is no longer there.

If they do not use a multiple LED structure but they still have a fluorescent conversion layer, the layer must be very thin and deposited on the top surface of the LED. It could consist of "quantum dots", like in some TV panels, i.e. very small crystals which emit light of a color depending on the composition and size of the nanocrystal when illuminated with ultraviolet or blue light.

However, "quantum dot" is a term that has already been used for a long time in marketing with the intention to suggest a superior technology. If they were using this, I expect that they would have bragged about it.

So from the wording of the press release I think that a multiple LED structure is more likely than a "quantum dot" conversion layer, even if the latter would provide both a better spectrum coverage and superior aging characteristics (by avoiding a color hue shift in old LEDs).

Presumably so, though the LEDs could be designed so that the peaks are relatively broad and overlapping, to give an acceptable spectrum coverage.

But the press release does not have any information about this, so the peaks could also be narrow, resulting in a poor CRI.

I believe that it is more likely to be something related to modern food processing than an environmental contaminant.

I had been obese for a long time, for more than a decade. During that time I did many failed attempts to lose weight, but eventually I did it in the right way and after about a year I had a weight more than 1.5 times lower than before.

That was more than a decade ago, and since then I kept whichever weight I desired. Nonetheless, to avoid gaining weight again, it was essential that I switched to eating only food that I cook myself from raw ingredients.

With the food that I cook myself, I plan the amount that I would eat and after eating that quantity I am satiated and I am not hungry during all day (I eat only twice daily, a breakfast after waking up and then the second meal in the evening).

On the other hand, if I eat food from a restaurant or ready-to-eat food from a supermarket, I am not satiated even after eating much greater quantities, and I become hungry again after a few hours.

The food that I cook myself has a greater percentage of protein and fat than typical for commercial food, only moderate salt, and most of it has no added sugar, but beyond that I have no clue where is the difference.

More protein and fat and less salt and sugar is likely to matter, but it cannot be a complete explanation, because there is a great difference even between the bread that I bake and commercial bread. My bread contains nothing else except flour, water, salt and yeast, but it is very tasty and after eating it I am satiated, while after eating a greater amount of commercial bread I would still want to eat more.

Copper has the advantage that unlike iron, which will be consumed completely by rust when exposed to humid air, the oxidation speed slows down with an increasing thickness of the oxidized layer (formed of copper carbonates), until further oxidation becomes negligible.

I would count "pipe" and "open" together as 0 (useful) syscalls, because both have been obsolete for a very long time (even if they occupy 2 slots in the syscall table and those 2 slots will remain occupied forever).

These 2 syscalls have a history typical for Linux syscalls, where frequently new syscall variants make completely obsolete their predecessors, but the old syscalls must still remain supported forever by the newer Linux kernels, to allow running legacy programs.

"pipe" has been obsoleted by "pipe2" (on 2008-10-09), which in turn has been obsoleted by "IORING_OP_PIPE".

"open" has been obsoleted by "openat", which in turn has been obsoleted by "IORING_OP_OPENAT".

Most users do not invoke Linux syscalls directly, but they use the standard C library, which has frequently shielded the end user from the evolution of the Linux syscalls. For instance, you might use the functions "open()" and "pipe()" in your C program, but the C library might invoke instead of those the more modern syscalls "openat" and "pipe2", after adjusting their parameters.

That's right.

Moreover, for a large number of traditional Linux syscalls (including the many variants of read/write/send/recv) there are now better alternatives that are invoked as subcommands of a single syscall: io_uring_enter.

The number of Linux syscalls depends on the architecture and on x86-64 there are over 450 Linux syscalls.

Nonetheless, about one third of those syscalls are obsolete (being replaced by newer improved syscalls), even if a large number of programs are still using them, and about one other third of them are rarely used in the environments familiar to most Linux users, like personal computers and small servers.

The obsolete syscalls inflate a lot the number of Linux syscalls, because there are a lot of syscalls that were originally defined with an inadequate set of parameters, then they were fixed by adding parameters or changing the meaning of the existing parameters. There are many syscalls were even 3 or 4 attempts were needed until reaching an acceptable definition for their parameters.

New programs should use only the newest improved syscalls, but the documentation of the Linux syscalls in various places is usually not up-to-date itself, so a lot of people are still using older syscalls, without being aware that they are suboptimal. So the obsolete syscalls will have to be supported forever by the Linux kernels (though in most cases when an obsolete syscall is invoked it just fills the parameters with adjusted values and then it jumps to the current syscall).

You are right that for any interplanetary human expedition a prerequisite is to be able to make a closed environment for humans, where carbon dioxide, water, food left-overs and almost all other waste products generated by humans are recycled, producing free oxygen, potable water and food.

However, this does not mean that other required technologies, like for transportation or for protection against dust, cannot be solved before.

I also agree that recycling technologies are actually more important than spacecraft technologies, because they are equally applicable on Earth, not only on the path to other planets or in bases established there.

I do not believe that interplanetary travel will be possible for humans otherwise than in spaceships with artificial gravity produced by rotation.

This not only would avoid the health problems (the experiments on mice in the ISS imply that a gravity as high as 2/3 of that of Earth might be necessary for preventing harmful effects during long-term missions) but it would also simplify many of the recycling technologies, because handling fluids and powders is difficult in weightlessness. It would also simplify the growing of plants or fungi.

That is only a problem of money.

In big cities there are a lot of people who, at least for a big part of the year, spend all their lives only inside their home apartment and inside their work office.

If someone had been willing to spend many times more money on a base in Antarctica, it could have been built to have a much greater interior space and with much more comfortable facilities, so that for the people living inside it there would not have been significant differences between living there and living in some big city of the Earth, especially now, when with modern communications they can speak face-to-face with anyone else on the Earth, at any time.

There are many tasks that are still impossible with the current knowledge and understanding, but making a closed human-sustaining environment and going to Mars are not among those.

These 2 tasks can be solved with only the current knowledge, but they depend on the solution of many technological problems that require only a lot of money and of work.

Only a fraction of the huge amounts of money that have been invested now in AI would suffice to solve these problems, if a serious effort would be done towards such goals.

Whether it is useful to spend so many resources on such goals is a different question, but developing the technologies for an almost-closed self-sustaining environment is something that certainly would also generate by-products that would be useful on Earth, not only in interplanetary expeditions.

Knowing even only the 1974 CRI of a light source is much better than knowing nothing about it.

A very good CRI does not guarantee a very good color reproduction, but a poor CRI guarantees a bad color reproduction.

The article does not explain what they use, but it seems to imply that there is no fluorescent conversion layer and the white light comes directly from the LED.

That could be done if the LED actually contains a multiple structure combining red, green and blue LEDs, but in the past such a combined LED had the disadvantage that in time the efficiency of the 3 components degraded at a different rate, which resulted in a color shift.

For now, the luminous efficiency of this LED is quite poor, unsuitable for lighting but only for indicator LEDs or display applications, but they claim that for such small LEDs even the traditional LEDs had poor efficiency and they hope to improve the efficiency later to more acceptable levels.

One more use of the classic secure password "123456" for a hidden account :-)

20% was the efficiency for very ancient engines.

Modern internal-combustion engines have 35% to 40% efficiency, with even efficiencies of over 50% for the very big 2-stroke Diesel engines used in ships.

Nonetheless that remains about half of the efficiency of electric vehicles and the energy efficiency of the latter can be greatly increased over this ratio by the recovery of the kinetic or gravitational energy, when braking or descending.

When you run inference yourself you have absolute control on what the model does.

The model itself is just dead weights, which cannot do any action by themselves.

All actions are done by your inference engine and harness, and you should take care about what you allow those to do.

Nutrients are divided into micronutrients, most of which are needed in quantities much smaller than 1 gram per day, i.e. vitamins, minerals, essential fatty acids and a few amino-acid derivatives, and macronutrients, which form the bulk of what you eat, i.e. carbohydrates, protein and fat.

What you mean is that modern wheat was selected for high production per area, which can be attained only when the seeds contain smaller amounts of micronutrients, so that their limited availability will not inhibit growth.

On the other hand, all plant seeds, including wheat seeds, in their dry form consist almost only of nutrients, unlike the other plant parts, which usually have very little nutrient content.

So wheat seeds and also the white flour made of them are very rich in nutrients, but only in 2 kinds of nutrients, starch and protein.

Animals, including humans, need a great number of essential nutrients in order to survive, around 50 different chemical substances.

White bread provides energy and protein that has a good amino-acid profile, except for low amounts of the amino acid lysine.

For complementary proteins and for the very small amounts of micronutrients that are required for a complete food, one must eat something else.

There exists no natural food that has a perfect composition that would allow humans to live eating only that (except mother milk for small babies).

So anyone must eat a combination of different kinds of foods. People who are rich might choose to eat some paleo diet or some keto diet and it is possible to conceive such diets that are healthy.

However most of the humans must allocate a limited budget for food, and within these constraints there are large areas in various places of the Earth, including Europe, where any healthy diet of optimum cost must include a non-negligible fraction of wheat.

For those who unfortunately suffer of celiac disease, a higher cost of food is unavoidable.

White flour has a slightly higher protein content (e.g. I bake bread from flour with 13% protein), but the important difference is that it is much cheaper, e.g. at least twice cheaper than whole wheat flour.

The reason for the price difference is unlikely to be due to a more expensive processing technology, but mostly from the economies of large scale processing, because the production of white flour is much greater.

Whole wheat flour has slightly higher amounts of the more valuable nutrients, but due to its high price it is an inefficient way to get those nutrients. A both cheaper and healthier diet can include white bread and larger amounts of other vegetables that are better sources of fiber, vitamins and minerals than whole wheat flour. (E.g. the food that I cook usually includes ingredients like lentils, carrots, parsnips, onions or garlic, broccoli or cauliflower, bell peppers, parsley or dill etc. Spending less on those in order to make more expensive whole wheat bread would provide much less desirable nutrients, so it would be a bad allocation of funds.)

After the appearance of durum wheat, and then of the bread wheat, the products made from emmer and einkorn (and later also from spelt) have always been more expensive, without having any decisive advantages.

Nonetheless, these minor varieties of wheat have remained important due to their ability to grow in soil or climate conditions where the more productive modern varieties of wheat fail.

So they were frequently used as "backup" crops, for the cases when bad weather or pests destroyed the main wheat crops.

As said in the parent article, they may become again more important where soil has been made worse by modern agricultural practices.

White bread is not devoid of nutritional value, because it is the cheapest source of proteins known to mankind. Legumes like lentils, beans or peas have a cost per protein content at least 2 to 2.5 times higher than wheat flour. Chicken meat and plant protein isolates have a cost per protein content at least 4 to 5 times higher than wheat flour.

White bread is also one of the cheapest sources of energy, though depending on the geographical location either maize or rice may be slightly cheaper sources of energy, but which provide much less protein.

Among cereal products, wheat bread has the highest protein content, except for oats, but oats are much more expensive per protein content.

If you eat white bread in preference to any other starchy products, like those based on rice, maize or potatoes, this ensures a higher protein intake per a given calories content, which enables a lower consumption of more expensive sources of proteins, like those based on legumes or on meat.

White bread cannot be the only food that one eats, because other kinds of foods must provide other nutrients, but it can provide at a minimum cost major fractions of the daily intake of proteins and energy.

After experimenting with many different healthy diets, I have settled on a variant that I consider optimal, where wheat bread that I bake myself at home typically provides about a third of my daily protein intake, so its nutritional value is quite important (and the fact that it is very tasty is a welcome bonus).

Unfortunately the article does not identify precisely the "miracle" wheat.

"Triticum turgidum" is ambiguous, because this wheat species has many different subspecies, with very different characteristics.

There are 2 important subspecies of "Triticum turgidum", emmer wheat, which was 1 of the 3 cereals domesticated at the beginning of the Neolithic (barley, einkorn wheat and emmer wheat), and durum wheat (a.k.a. pasta wheat or macaroni wheat), which was produced from emmer wheat by a genetic mutation, several thousand years after domestication.

From the article, it is not clear if the discussed wheat is just some cultivar of emmer wheat or it belongs to a more exotic subspecies of "Triticum turgidum".

Any references from the Bible are unlikely to describe anything else but some variety of emmer wheat.

While most wheat-based food is nowadays produced from either hexaploid bread wheat or tetraploid durum wheat, there are on the market various niche products (e.g. some kinds of biscuits) made from spelt wheat, emmer wheat or einkorn wheat (though the product labels frequently confuse the hexaploid spelt wheat with the tetraploid emmer wheat).

No, Einkorn is not the ancestor of all cultivated wheat varieties, unless you extend the history of wheat a very long time before domestication, when that becomes somewhat true, because the wild ancestor of emmer wheat was produced by genome duplication from a wild ancestor of einkorn wheat.

At the start of the Neolithic, besides barley, 2 species of wheat were domesticated separately and they evolved through domestication into einkorn wheat and emmer wheat.

Einkorn wheat has always remained a minor crop, while either barley or emmer was the major crop, depending on soil and climate. For instance in the early Ancient Greece barley was the most important, while in the early Roman Republic emmer was the more important. Later, emmer ("far" in Latin) was mostly replaced by durum wheat ("triticum" in Latin), and even later durum wheat was mostly replaced by the hexaploid bread wheat ("siligo" in Latin).

Besides the original emmer and einkorn, other wheat subspecies have appeared many thousands of years later after domestication, either through mutations, like the tetraploid durum wheat (pasta wheat) or through hybridization, like the hexaploid bread wheat (and also the hexaploid spelt wheat).

Arginine is a "conditionally essential" amino-acid, i.e. there are circumstances when the internal production is insufficient, so it must exist in food.

The need for arginine may exist during some illnesses and not for children in general, but for very young babies, especially for those born prematurely.

Whatever happened, it was temporary, because radio contact was established again after a 2-day pause.

A big unknown planet has crossed the path between Voyager 1 and the Earth, blocking the radio signals for 2 days !

(This is not impossible, because a planet so far away would have an extremely low angular velocity, so an occultation could take so long even for a not very big planet.)

While the conclusion that frequent ejaculation reduces the risk of prostate cancer was a rather obvious and expected result, what is quite surprising is that the frequency of ejaculations when young had a greater weight than the frequency of ejaculations in old age, despite the fact that what happened when young was separated by decades from the diagnostics of prostate cancer when old.