Daniel Lemire's blog

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Science and Technology links (March 17, 2017)

We live in a world where the most powerful companies in the world have super smart people working on trying to emulate human intelligence in machines. Yann LeCun, a Frenchman who directs Facebook’s artificial intelligence research group, tells us that, soon, computers could acquire what he calls “common sense”. I can’t resist pointing out that this would put machines ahead of most human beings. Kidding aside, it seems that the goal is to produce software that can act as if it understood the world we live in. There is a ball up in the air? It is going to come down. Someone dressed in dark is waiting in an alley? He might be waiting to mug someone. Instead of having to train machines for specific tasks, and having them perform well only on these specific tasks, the goal would be to start with software that can reason about the world, and then build on that. Want to build an automated vacuum cleaner? Want it to stop whenever someone enters the room? Maybe in the future, software will be smart enough to understand well enough what “someone enters the room” means without months of tweaking and training. Given that software can be copied inexpensively if one company succeeds at building one such general-purpose engine, it could quickly apply it to a wide range of problems, creating specialist engines like my automated vacuum cleaner. In 2017, that’s still science fiction but people like LeCun are not clowns: they got tangible results in the past. People use their ideas to solve real problems, in the real world. So who knows?

In Myths that will not die, Megan Scudellari review a few scientific myths that you may believe:

  • Screening saves lives for all types of cancer. The truth is that cancer screening is often negative. The story usually goes that if they catch cancer early, your chance of survival goes up. The problem is that many cancers will kill you no matter what, knowing about them early just makes your miserable longer. And lots of cancers would not have killed you anyhow, so you are just going to go through stress and painful therapies for no good reason.
  • Antioxidants are good. You should eat your fruits and vegetables. Take your vitamins. It is full of antioxidants. And so on. The idea underneath is that your body is like an automobile and it is “oxidizing” (rusting).You can actually see this process: gray hair is a form of oxidation. This was one of the flawed theory of why we age: oxidation kills us. Take antioxidants and you will prevent this process. Not so fast! Your body has pretty good antioxidants. Taking more may not help, it may even cause some slight harm. If anything, free radicals, in moderation, might be good for you.
  • Human beings have exceptionally large brains. We are pretty much in line with other primates. However, our brains are configured somewhat differently.- Individuals learn best when taught in their learning style. This is pure junk. There is no such thing as a “visual learner”. That people keep on insisting that it must be, despite all the scientific evidence being against it… is really puzzling.- The human population is growing exponentially and we are doomed. The richer a country is, the slower its population grows. Advanced countries like Germany and Japan have a population decline. Because the world is getting richer, all continents but Africa will reach a population plateau within a few decades. Even Africa will catch up. Meanwhile, we produce, today, enough food to feed 10 or 12 billion people. So yes, there will be more human beings alive in 50 years, but there may actually be fewer in 100 years. Meanwhile, having more people means to have more engineers and scientists, more entrepreneurs, more astronauts.

By the way, by mere extrapolation, it is quite certain, I think, that there won’t be anything that we would recognize as “human” in a couple of centuries… if technology keeps getting better. Any long-term doomsday scenario that ignores technology as a factor is just ridiculous.

The diseases of old age are tremendously expensive. Dementia, the diseases affecting cognition are particularly cruel and expensive:

The worldwide costs of dementia were estimated at United States (US) $818 billion in 2015, an increase of 35% since 2010 (…) The threshold of US $1 trillion will be crossed by 2018.

It is hard to wrap our head around how much of an expense that is. Let me try. If we did not have to pay for dementia, we could afford five million well-paid researchers, engineers, and scientists at 200k$ a year each. Care to wonder what 5 million of them could achieve every single year? I don’t know if we will have cures for dementia in 10 or 20 years, but if we do, we will be immensely richer.

Regarding Parkinson’s… the terrible disease that makes people shake uncontrollably, lose the ability to speak normally… Ok. So right now, there is nothing we can do to reverse or slow this disease, at best we can help control the damages. We need to do better. Almost every day, there is a grand proclamation that a cure is around the corner, but it always disappoints. The latest one I have seen is nilotinib. It is a drug used to treat some cancers. It turns out that it has another great benefit: it boost autophagy. Autophagy is the process by which your body “eats itself”. I know it sounds bad, but that’s actually a great thing if you are a multicellular organism. The idea is that repair is too hard, so what the body does is to eat the broken stuff and then use the byproduct to rebuild anew. If you could crank up autophagy, you would assuredly be healthier. So, they think that in cases of Parkinson’s, the body faces an accumulation of garbage that is so bad that it leads to cell death. If you could convince the body to eat up the garbage, you might be able to stop the progression of the disease. It would not, by itself, reverse Parkinson’s, but once the damage stops worsening, the body can be given a chance to route around the damage, and we could start thinking about damage-repair therapies. As it stands, with damages accumulating at a high rate, there is little we can do until we slow it down. Anyhow, in mice designed to suffer from Parkinson’s, nilotinib stops the disease. There are now large clinical trials to see if it works in human beings. Could a cure for Parkinson’s be around the corner?

Technology is very much about globalization. Many people are concerned, for example, with the fact that the United States is running trade deficits year after year. To put it in simple terms, Americans buy many good from China, but China buys comparatively fewer goods from the USA. Could this go on forever? Economist Scott Sumner explain that it can:

A common mistake made by famous economists is to confuse statistical measures (…) with the theoretical concept (…). In terms of pure economic theory, the US sale of an LA house to a Chinese investor is just as much an “export” as the sale of a mobile home that is actually shipped overseas. But one is counted as an export and one is not.

It is a common problem in science that we measure something that differs from our model. The difference appears irrelevant until it is not.

Ever since I was a teenager, I have been told that cholesterol causes heart disease. Statins, a family of drugs to drastically lower cholesterol, is making pharmaceutical companies very rich. A controversial study published last year suggests that lowering cholesterol might be vain:

What we found in our detailed systematic review was that older people with high LDL (low-density lipoprotein) levels, the so-called “bad” cholesterol, lived longer and had less heart disease.

Lowering cholesterol with medications for primary cardiovascular prevention in those aged over 60 is a total waste of time and resources, whereas altering your lifestyle is the single most important way to achieve a good quality of life

This does not mean that statins do not have benefits. They seem to be working for men who have had a prior cardiovascular incident. However, do they work because they lower cholesterol? This being said, taking low-dose aspirin has also some benefits regarding cardiovascular health, and it is much cheaper. Both aspirins and statins have side-effects, of course.

Going to space is bad for your health. It seems to cause some form of accelerated aging. The effect remains even if you keep astronauts active (through special exercises) and if you shield them as best as possible from radiation. (Spending a month in space does not expose you to more radiation that what flight crew experience in a lifetime, yet pilots do not suffer from accelerated aging.) There are many unknowns in part due to the fact that there are very few astronauts. We know that all of them are closely monitored for health problems. Surprisingly, up until now, retired astronauts did not receive government-paid health care. Given that they are effectively Guinee pigs and living science experiments, I would have thought that they were covered. This is about to change.

IBM claims that it is reaching human-like speech recognition levels on some very difficult tests.

Last year, IBM announced a major milestone in conversational speech recognition: a system that achieved a 6.9 percent word error rate. Since then, we have continued to push the boundaries of speech recognition, and today we’ve reached a new industry record of 5.5 percent.

It seems that human parity would be 5.1 percent. So we are really close to human parity. Maybe next year? I tend to be skeptical of such announcements, whether they come from IBM, Microsoft or Google. I much prefer to assess deployed technologies and it is clear that neither Google nor Apple is at human-level speech recognition. So let us take this with a grain of salt, for now.

I take most of the academic research with a large grain of salt. My experience is that, too often, I can’t reproduce the work of my peers. Sometimes they flat out lie about their methods, but most often, they were just careless. I am sure my own work has problems, but I am have worked hard to ensure that all my papers are backed by freely available code and data. This way, at least, it is often easy to check my work. We already know that most psychology studies cannot be replicated. What about cancer research? Cancer research is the best-funded research, period. If Computer Science is a house in the suburbs, cancer is the Trump tower. If anything should be top notch, it is cancer research. Yet it does not look good:

Glenn Begley and Lee Ellis from Amgen said that the firm could only confirm the findings in 6 out of 53 landmark cancer papers—just 11 percent. Perhaps, they wrote, that might explain why “our ability to translate cancer research to clinical success has been remarkably low.”

If you asked 20 different labs to replicate a paper, you’d end up with 10 different methodologies that aren’t really comparable. (…) If people had deposited raw data and full protocols at the time of publication, we wouldn’t have to go back to the original authors (…)

Simply put, we are paying for research papers, and so we get them, but little else. To turn things around, scientists need to have skin the game. If their work does not lead to a cure, and it won’t if it is not reproducible, they need to pay a price. On the topic of cancer, some researchers claim that they have figured out how to block the spread of cancer by disabling Death Receptor 6 (in mice, at least). Who comes up with these names? Anyhow, cancer is mostly a dangerous disease because it spreads. If tumors remained where they are, they would either not cause much harm, or be easy to manage (or remove). Sadly, many cancers tend to spread uncontrollably through our blood stream. It seems that it punches through the walls of blood vessels and moves on from there. Speculatively, we could maybe disable this ability in cancer is make it a much less dangerous disease. Maybe. But can we reproduce the Death Receptor 6 experiments?

The lack of reproducibility also plagues gerontology and development biology. Researchers have been studying the lifespan of short-lived worms for decades. At a high-level, this is compelling research. Take a compound, bath worms in it, and see whether they live shorter or longer. If biology had maximized lifespans, then it would be very hard to find compounds that prolong life, but it is not so hard in practice. What is hard is to get the same compound to extend the life of worms robustly across different species of worms and in a way that competing labs can reproduce. Lucanic et al. showed that one compound (and only one in their test) robustly extended the lifespan of a wide variety of worms: Thioflavin T. What is this magical compound and can you order it online? It is a fluorogenic dye that is routinely used in medical research. Don’t drink the stuff just yet. On a related note, methylene blue, another dye, has also been reported to have great health properties. Here is a vision for you: the world is filled with ageless centenarians, but they are either dyed in yellow, blue or green. So maybe you want to remain healthy for a long time with something less colorful and easier to find. What about baking soda? Scientists who want to be taken seriously, call the stuff NaHCO3. Wesson in Is NaHCO3 an antiaging elixir? tells us that it maybe be good for our health:

Emerging evidence supports that the largely acid-producing diets of developed societies induce a pathological tissue milieu that contributes to premature death, mediated in part through vascular injury, including vascular calcification.

Speaking for myself, before I start consuming large quantities of baking soda, I’ll expect scientists to make a very convincing case. The stuff does not taste very good.

To remain youthful longer, maybe you do not need to do anything at all. Stenzaltz tell us that we are aging slower as time passes, in the following sense:

the generation of American men who fought in World War II and are now in their 90s lived, on average, about eight years longer than their great-grandfathers who fought in the Civil War, once they reached adulthood.
According to the 1985 United States Health Interview Survey 23 percent of Americans aged 50 to 64 reported limitations on daily activities due to chronic illness; in 2014, this was down to 16 percent
Perhaps most striking, a new study has discovered that over the past two decades the incidence of new dementia cases has dropped by 20 percent. Men in the United Kingdom develop dementia today at the same rate as men five years younger in the 1990s (…)

It is fairly easy to see why people who fought in the WW II would be healthier than previous generations: they had access to inexpensive antibiotics. Antibiotics are our first line of defense against infectious diseases. Yet it is much less clear why people in their fifties would be healthier today than they would have been in the 1980s. Why would dementia rates fall? It demands an explanation and I see none being offered.

DNA is used by biology as an information storage mechanism, not unlike our digital storage devices. It seems that we could back up the entire Internet on a gram of DNA. The real challenge, of course, would be to access the information quickly. Biology is often not in a hurry. Google users are. Pangloss has a nice review of the technology where he hammers the point that it is just too expensive to write data to DNA:

Although this is useful research, the fact remains that DNA data storage requires a reduction in relative synthesis cost of at least 6 orders of magnitude over the next decade to be competitive with conventional media, and that currently the relative write cost is increasing, not decreasing.

There is an emerging consensus that as we age, our blood acquires a high level of harmful factors. These factors may not be harmful by themselves, but having too much of it for a long time could be detrimental to our bodies. We are seeing the first glimpses at technology to block or remove the bad stuff from old blood:

Yousef has found that the amount of a protein called VCAM1 in the blood increases with age. In people over the age of 65, the levels of this protein are 30 per cent higher than in under-25s.

To test the effect of VCAM1, Yousef injected young mice with blood plasma taken from older mice. Sure enough, they showed signs of aging (…) Blood plasma from old people had the same effect on mice. (…)

These effects were prevented when Yousef injected a compound that blocks VCAM1. When the mice were given this antibody before or at the same time as old blood, they were protected from its harmful effects.

So we can envision therapies that “rejuvenate” our blood. And no, it won’t involve drinking the blood of the young. Rather you could imagine a device that would scan your blood, determine that you have too much of protein X and decide to remove some of it to bring it back to a youthful level. Still science fiction, but I bet that we shall be trying it out on mice soon.

A nasty problem that affects some of us is retinal degeneration. Basically, you start to have a hard time seeing, you go to your doctor, and he tells you that your retina is going to shred, and it is only going to get worse. “Go buy a white cane now.” That would not be a good day. If your retina degenerates on its own, it is not like glasses will help you. But Yu et al. showed that you could use a nifty new gene therapy to prevent retinal degeneration. Basically, they reprogram the cells, in vivo, and all is well. It works in mice.

On the topic of the retina, three ladies went to a clinic in Florida for macular degeneration, a form of age-related retinal degeneration. They paid $5000 for an experimental stem-cell therapy and came out blind. The experimental therapy is not the problem per se, one has to try new things from time to time. If you are going blind and someone suggests you try something that might restore your eyesight… wouldn’t you want to try it? At some point, you have little to lose and much to gain. Moreover, some people might be motivated by the fact that they help advance science. The real problems arise because the therapy was not administered in a sensible fashion. For example, they treated both eyes at the same time. That’s obviously unnecessarily dangerous. They also charged the patients for something that is an experiment. Again, that’s less than ideal. For unproven therapies, you’d really prefer not to charge your Guinee pigs for the experiment. Stem cells have great potential in medicine, but we are not yet at the point where we can do in vivo regeneration of organs. At least, we can’t do it safely.

So having children is stressful and a lot of work. It is hard. But did you know that parents live longer? Evidently, having to work hard is not a negative when it comes to health and longevity.

Is the Sun bad or good for your skin? It may depend on the wavelength. High-frequency light (UV-A and UV-B) seems to be bad (burns, cancer, wrinkles and so forth), hence the ubiquitous sunscreen, but low-frequency (infrared) light might be good for us:

In the last decade, it has been proposed that the sun’s IR-A wavelengths might be deleterious to human skin and that sunscreens, in addition to their desired effect to protect against UV-B and UV-A, should also protect against IR-A (…) IR-A might even precondition the skin–a process called photo prevention–from an evolutionary standpoint since exposure to early morning IR-A wavelengths in sunlight may ready the skin for the coming mid-day deleterious UVR. Consequently, IR-A appears to be the solution, not the problem. It does more good than bad for the skin.

So maybe you should get an infrared lamp to improve your skin? Sounds less painful than having to eat baking soda.