Tag: links

Science and Technology links (June 15th 2019)

Science and Technology links (March 23rd 2019)

  1. Half of American households subscribe to “Amazon Prime”, a “club membership” for Amazon customers with monthly fees. And about half of these subscribes buy something from Amazon every week. If you are counting, this seems to imply that at least a quarter of all American households order something from Amazon every week.
  2. How do the preprints that researchers post online freely differ from genuine published articles that underwent peer review? Maybe less than you’d expect:

    our results show that quality of reporting in preprints in the life sciences is within a similar range as that of peer-reviewed articles

  3. Very low meat consumption might increase the long-term risk of dementia and Alzheimer’s.
  4. We appear to be no closer to find a cure for Alzheimer’s despite billions being spent each year in research and clinical trials. Lower writes:

    Something is wrong with the way we’re thinking about Alzheimer’s (…) It’s been wrong for a long time and that’s been clear for a long time. Do something else.

  5. Many researchers use “p values” (a statistical measure) to prove that their results are “significant”. Ioannidis argues that most research should not rely on p values.
  6. Eating nuts improves cognition (nuts make you smart).
  7. As we age, we become more prone to diabetes. According to an article in Nature, senescent cells in the immune system may lead to diabetes. Senescent cells that are cells that should be dead due to damage or too many divisions, but they refuse to die.
  8. Hospitalizations for heart attacks have declined by 38% in the last 20 years and mortality is at all time low. Though clinicians and health professionals take the credit, I am not convinced we understand the source of this progress.
  9. In stories, females identify more strongly with their own gender whereas males identify equally with either gender.
  10. Theranos was a large company that pretended to be able to do better blood tests. The company was backed by several granted patents. Yet we know that Theranos technology did not work. The problem we are facing now is that Theranos patents, granted on false pretenses and vague claims, remain valid and will hurt genuine inventors in the future. If we are to have patents at all, they should only be granted for inventions that work. Nazer argues that the patent system is broken.
  11. Smaller groups tend to create more innovative work, and larger groups less so.
  12. The bones of older people become fragile. A leading cause of this problem is the fact stem cells in our bones become less active. It appears that this is caused by excessive inflammation. We can create it in young mice by exposing them to the blood serum of old mice. We can also reverse it in old mice by using an anti-inflammatory drug (akin to aspirin).
  13. Gene therapy helped mice regain sight lost due to retinal degeneration. It could work in human beings too.
  14. Based on ecological models, scientists predicted over ten years ago that polar bear populations would soon collapse. That has not happened: there may be several times more polar bears than decades ago. It is true that ice coverage is lower than it has been historically due to climate change, but it is apparently incorrect to assume that polar bears need thick ice; they may in fact thrive when the ice is thin and the summers are long. Crowford, a zoologist and professor at the University of Victory tells the tale in her book The Polar Bear Catastrophe That Never Happened.

Science and Technology links (February 16th, 2019)

    1. In their new book Empty Planet, Bricker and Ibbitson argue that within the next 30 years, Earth’s population will start to rapidly decline. They believe that official population predictions overestimate future populations because they fail to fully take into account accelerating cultural changes.
    2. It is believed that senescent cells are a major driver of age-related conditions. Senescent cells often occur when cells are the results of too many divisions (beyond the Hayflick limit). Our hearts age, but their cells do not divide very much. That is a problem because our hearts have a limited ability to repair themselves (by creating new cells) but this should protect our hearts from senescent cells… Yet Anderson et al. found that there are senescent cells in the heart: basically cells can become senescent due to damage. What is more exciting is that they found that by clearing these cells in old mice, they could effectively rejuvenate their hearts. Furthermore, there is a growing number of therapies for removing senescent cells. Furthermore, there are ongoing (early) clinical trials to measure the effect of removing senescent cells in human beings. Initial results are encouraging:

      The doctors found that nine doses of the two pills over three weeks did seem to improve patients’ ability to walk a bit farther in the same amount of time, and several other measures of well-being.

      More trials will start this year.

    3. Goldacre et al. looked at how well the most prestigious journals handle the agreed upon set of standards for reporting scientific trials:

      All five journals were listed as endorsing CONSORT, but all exhibited extensive breaches of this guidance, and most rejected correction letters documenting shortcomings. Readers are likely to be misled by this discrepancy.

      (Source: A. Badia)

    4. A new drug appears to reverse age-related memory loss, in mice.

Science and Technology links (February 9th, 2019)

  1. Though deep learning has proven remarkably capable in many tasks like image classification, it is possible that the problems they are solving remarquably well are just simpler than we think:

    At its core our work shows that [neural networks] use the many weak statistical regularities present in natural images for classification and don’t make the jump towards object-level integration of image parts like humans.

    This challenges the view that deep learning is going to bring us much closer to human-level intelligence in the near future.

  2. Though we age, it is unclear how our bodies keep track of the time (assuming they do). Researchers claim that our blood cells could act as time keepers. When you transplant organs from a donor, they typically behave according to the age of the recipient. However, blood cells are an exception: they keep the same age as the donor. What would happen if we were to replace all blood cells in your body with younger or older ones?
  3. A tenth of all coal is used to make steel. This suggests that it might be harder than people expect to close coal mines and do away with fossil fuels entirely in the short or medium term.
  4. Elite powerlifters have suprising low testosterone (male homone) levels. This puts a dent in the theory that strong men have high testosterone levels.
  5. Chimpanzees learn to crack nuts faster than human beings. This challenges the model that human beings are cognitively superior.
  6. It seems that the male brain ages more rapidly than the female brain.
  7. Grant argues that vitamin D supplements reduce cancer rates, but that medicine is slow to accept it.
  8. Women prefer more masculine looking men in richer countries. I do not have any intuition as to why this might be.
  9. Geographers claim that the arrival of Europeans to America, and the subsequent reduction of population (due mostly to diseases) lead to a global cooling of worldwide temperatures. It seems highly speculative to me that there was any measurable effect.
  10. The New York Times has a piece of a billionnaire called Brutoco who says that “he spends much of his time flying around the world lecturing on climate change” and lives in a gorgeous villa surrounded by a golf course. There is no talk of his personal carbon footprint.

Science and Technology links (January 26th, 2019)

  1. We are training many more doctors (PhDs) than we need, when looking at the number of new faculty positions. In science, this has been true since at least the 1980s. It is not uncommon for even so-so faculty positions to receive dozens of top-notch applicants with PhDs. Yet it is often believed that for a new PhD, anything short of a professorship is a failure. Logically, PhD students should prepare for a job in industry and I often try to prepare my own students in this way. Some students believe that hinting that they need to prepare for an industry job is an insult. Jeff Dean is probably one of the ten most famous computer scientists in the world. He works for Google and he has a PhD. He wrote on Twitter:

    When I was finishing grad school, I was applying for both academic faculty positions and industrial research positions. Only got one academic interview (& offer), and not from a top- or even mid-tier place, so I went into industrial research. It’s turned out okay.

    My own unpopular view is that governments put too much money toward funding new PhDs. We confuse too easily training new PhDs with doing science. We generate many, many PhDs that are too often poorly prepared for the actual jobs they may find.

  2. Cape Town (South Africa) and Magadan (Russia) are 22 thousands kilometers apart. It would take two years to walk the distance. Though it is a long time, it also puts in perspective the fact that it often took hundreds of years for technological innovations to spread from one corner of the Earth to the other.
  3. We have no serious evidence that artificial sweeteners are harmful.
  4. The Guardian tells us that up to 1,500 private flights will bring world leaders to Davos to take urgent action on climate change. Al Gore, the author of the celebrated “Inconvenient Truth” documentary on climate change resides in a 10,000 square-foot home with eight bathrooms, he uses orders of magnitude more electricity than regular folks. He also charters private flights. Similarly, in my experience, climate-change researchers (including some close colleagues of mine) routinely fly to remote locations. The counterargument is usually that people buy carbon offsets. Roughly speaking, what these offsets do is, for example, pay for a poor village to receive a solar panel, thus replacing their inefficient CO2-emitting generator. That is what happens when these carbon offset programs are genuine and well managed. However, do these offets really work? That is, will the poor village with subsized electricity now use this new wealth to buy a new car? Who gets to measure the environmental effect of these carbon offsets, and what are their incentives? Anderson wrote an essay for Nature a few years ago on this topic:

    Offsetting is worse than doing nothing. It is without scientific legitimacy, is dangerously misleading and almost certainly contributes to a net increase in the absolute rate of global emissions growth.

    Corbera and Martin are similarly skeptical:

    carbon-offsetting activities have (…) not been able to meet their stated goals (…) the carbon-offset market is designed to serve polluters

    A major initiative to offset climate change is REDD: in short, rich countries pay poor countries to preserve their forests. The key idea, just like other carbon offsets, is that the rich country does not need to change its practices. In Why REDD will fail, DeShazo et al. explain why it may not work as you expect:

    the eventual goal of REDD is that developed countries will pay developing countries to protect and enhance their forests in order to offset carbon emissions. This practice allows developed countries to claim that they are reducing emissions when no actual reduction has taken place (…) should a developing country adopt REDD (…) this does not equate to a reduction in deforestation.

    Carbon offsets work in specific ways: they make some people feel better and allow virtue signalling. However, you should not believe that we could all live in mansions with eight bathrooms and fly private jets without increasing our carbon emissions, if only we paid for carbon offsets. You should not believe that researchers and world leaders can keep on organizing conferences at Davos without significant environmental impacts. These are extraordinary claims that require extraordinary evidence. They just happen to be convenient beliefs.

  5. As we age, our bones tend to break more easily. We also accumulate senescent cells: cells that should be dead but somehow survive. Though it is not yet ready for actual therapies, we now have technology to remove senescent cells. Farr and Khosla find that removing senescent cells in old mice prevent age-related bone loss and frailty.
  6. A bacteria that causes gum disease might cause Alzheimer’s.
  7. Scandinavians with weird names were more likely to emigrate to the United States. People with weird names would be more individualistic. Both times my wife was pregnant, I insisted on us picking original first names. I would define myself as an individualist.

Science and Technology links (December 1st 2018)

  1. Autism affects about 1% of the population and four times as many males as females.
  2. In older highly educated people, drinking 2 cups of coffee a day is associated with a reduced mortality rate of 22%. (This does not mean that drinking coffee makes you less likely to die, but it might.)
  3. Amazon, the e-commerce giant, is entering the chip-making business with its AWS Graviton processors, designed for cloud servers and based on an ARM architecture (like the processor in your phone). The initial reports are somewhat negative.
  4. Student assignments are graded automatically at the University of Cafornia Berkeley, and the result is that

    ratings for teaching effectiveness have reached their highest level ever in recent semesters.

    (Credit: S. Downes)

  5. A Chinese professor helped produced two genetically edited babies. The intention is that they be immune to HIV. Harvard’s professor George Church is supportive of this bold move.

Science and Technology links (November 18th 2018)

  1. It seems that reducing your carbohydrate (sugar) intake might be a good way to lose weight:

    lowering dietary carbohydrate increased energy expenditure during weight loss maintenance. This metabolic effect may improve the success of obesity treatment, especially among those with high insulin secretion.

    I should warn that this study refers to “lowering sugar” not getting rid of it entirely.

  2. 85% of the more than $100bn a year spent on medical research globally is wasted avoidably
  3. Collison and Nielsen write:

    science has slowed enormously per dollar or hour spent. That evidence demands a large-scale institutional response. It should be a major subject in public policy, and at grant agencies and universities

    While I accept their demonstration, it is not clear what (if anything in particular) is causing this lack of productivity.

    Collison and Nielsen fall short of offering a solution. Maybe we ought to reinvent discovery?

  4. A man is going to court so that he can be considered 20 years younger than what his birth date indicates.

Science and Technology links (November 10th, 2018)

  1. It already takes more energy to operate Bitcoin than to mine actual gold. Cryptocurrencies are responsible for millions of tons of CO2 emissions. (Source: Nature)
  2. “Half of countries have fertility rates below the replacement level, so if nothing happens the populations will decline in those countries” (source:BBC)
  3. According to Dickenson et al., 8.6% of us (7.0% of women and 10.3% of men) have difficulty controlling sexual urges and behaviors.
  4. A frequently prescribed drug family (statins) can increase your risk of suffering from ALS by a factor of 10 or 100.
  5. Countries were people are expected to live longest in 2040 are Spain, Japan, Singapore, Switzerland, Portugual, Italy, Israel, France, Luxembourgh, Australia. Not included in this list is the USA.
  6. Smart mirrors could monitor your mood, fitness, anxiety levels, heart rate, skin condition, and so forth.
  7. When you are trying to determine whether a drug is effective, it is tempting to look at published papers and see whether they all agree on the efficacity of the drug. This may be quite wrong: Turner et al. show a strong bias whereas negative results are never published.

    Studies viewed by the FDA as having negative or questionable results were, with 3 exceptions, either not published (22 studies) or published in a way that, in our opinion, conveyed a positive outcome (11 studies). According to the published literature, it appeared that 94% of the trials conducted were positive. By contrast, the FDA analysis showed that 51% were positive. Separate meta-analyses of the FDA and journal data sets showed that the increase in effect size ranged from 11 to 69% for individual drugs and was 32% overall.

    Simply put, it is far easier and profitable to publish positive results so that’s what you get.

    This means that, by default, you should always downgrade the optimism of the litterature.

    Simply put: don’t be too quick to believe what you read, even if it is comes in the form of a large set of peer-reviewed research papers.

  8. Richard Jones writes “Motivations for some of the most significant innovations weren’t economic“.
  9. Cable and satellite TV is going away.
  10. “What if what students really want is not to be learners, but alumni?” People will prefer an academically useless program from Harvard to a complete graduate program from a lowly school because they badly want to say that they went to Harvard.
  11. Drinking coffee abundantly protects from neurodegenerative diseases.

Science and Technology links (November 3rd, 2018)

  1. Bitcoin, the cryptocurrency, could greatly accelerate climate change, should it succeed beyond its current speculative state.
  2. Crows can solve novel problems very quickly with tools they have never seen before.
  3. The new video game Red Dead Redemption 2 made $725 million in three days.
  4. Tesla, the electric car company, is outselling Mercedes Benz and BMW while making a profit.
  5. Three paralyzed men are able to walk again thanks to spinal implants (source: New York Times). There are nice pictures.
  6. Human beings live longer today than ever. In the developed world, between 1960 and 2010, life expectancy at birth went up by nearly 20 years. It consistently goes up by about 0.12 years per year. However, it is not yet clear how aging and death have evolved over time. Some believe that there is a “compression” effect: more and more of us reach a maximum, and then we suddenly all die at around the same age. This would be consistent with a hard limit on human lifespan and I think it is the scenario most biologists would expect. There is also the opposite model: while most of us die at around the same age, some lucky ones survive much longer. According to Zuo et al. (PNAS) both models are incorrect statistically. Instead, the curve is advancing as a wave front. This means that as far as death is concerned, being 68 today is much like being 65 a generation ago. This is surprising.

    (…) we find no support for an approaching limit to human lifespan. Nor do our results suggest that endowments, biological or other, are a principal determinant of old-age survival.

    Assuming that Zuo et al. are correct, I do not think we have a biological model at the ready to explain this statistical phenomenon.

  7. Suppose that you gave a cocktail of drugs approved for human consumption to worms. By how much do you think you could extend their lifespan? The answer is at least by a factor of two. They tried their best cocktails with fruit flies and showed benefits there as well. It is much harder to manipulate the lifespan of large mammals like human beings, but these results support the theory that drug cocktails could increase human lifespans. They may already being doing so.
  8. Amazon is hiring fewer workers, maybe because it is getting better at automation. (speculative) It seems that Amazon is mostly denying the story, hinting that they are still creating more and more jobs.
  9. No primate except for human beings, undergoes menopause. Very few animals have menopause: primarily some whales and human beings. I don’t think we know why menopause evolved.
  10. Total direct greenhouse gas emissions from U.S. livestock have declined 11.3 percent since 1961, while production of livestock meat has more than doubled.
  11. Male and female animals respond very differently to anti-aging strategies and they age very differently:

    One particularly odd thing in humans is that though women live longer, they are nonetheless more prone to miserable but non-deadly ailments such as arthritis (…) Lethal illnesses such as heart disease and cancer strike men more often. Although Alzheimer’s strikes women more than men, for unknown reasons.

    We do not know why there is such a sharp difference between males and females regarding health and longevity. However, some believe that the current historical fact that women live many years more than men is due to the fact that antibiotics disproportionally helped the health of women.

  12. Vegans more frequently suffer from bone fractures.
  13. Teaching by presenting worked examples seems to be most efficient. Students get the best grades with the least work.This appears self-evident to me. It is curious why worked examples are not more prevalent in teaching.
  14. A company called Grifols claims to have a drug that can measurably slow down the progression of Alzheimer’s. For context, we currently have no therapy to slow or reverse Alzheimer’s, so even a small positive effect would be a tremendous breakthrough. However, there has been many, many false news regarding Alzheimer’s and this report appears quite preliminary.

Science and Technology links (July 15th, 2018)

  1. One of the problems that occur with aging is that your immune system becomes less efficient, less able to learn.
    If we could reverse this effect, it would be akin to rejuvenation. And it seems to be around the corner according to a new article published by Science:

    The objective of this phase 2a randomized, placebo-controlled clinical trial was to determine whether low-dose mTOR inhibitor therapy enhanced immune function and decreased infection rates in 264 elderly subjects given the study drugs for 6 weeks. A low-dose combination (…) was associated with a significant (P = 0.001) decrease in the rate of infections reported by elderly subjects for a year after study drug initiation. In addition, we observed an up-regulation of antiviral gene expression and an improvement in the response to influenza vaccination in this treatment group. Thus, selective TORC1 inhibition has the potential to improve immune function and reduce infections in the elderly.

  2. Nature reports on a technique that could massively accelerate artificial neural networks:

    Our method replaces artificial neural networks fully-connected layers with sparse ones before training, reducing quadratically the number of parameters, with no decrease in accuracy.

    Whether this makes it to production server is another story but “reducing quadratically the number of parameters” sounds impressive.

    In related news, you can run neural network software on DNA to recognize molecular patterns.

  3. We live longer and longer, but what good is that if your mind is not intact? Thankfully, between 2000 and 2010, most of the increase in life expectancy has been concentrated in cognitively healthy years in this 10 year period.
  4. As we age, we accumulate “old” cells called senescent cells. They should die but they fail to do so. It seems that senescent cells are really bad for us. Thankfully we can clear them out and get benefits, the evidence is growing:

    Here we demonstrate that transplanting relatively small numbers of senescent cells into young mice is sufficient to cause persistent physical dysfunction, as well as to spread cellular senescence to host tissues. Transplanting even fewer senescent cells had the same effect in older recipients and was accompanied by reduced survival, indicating the potency of senescent cells in shortening health- and lifespan. The senolytic cocktail, dasatinib plus quercetin, which causes selective elimination of senescent cells, decreased the number of naturally occurring senescent cells and their secretion of frailty-related proinflammatory cytokines in explants of human adipose tissue. Moreover, intermittent oral administration of senolytics to both senescent cell–transplanted young mice and naturally aged mice alleviated physical dysfunction and increased post-treatment survival by 36% while reducing mortality hazard to 65%.

  5. Vegetarian men are more likely to suffer from depression.
  6. Naked mole rats are ugly mammals that are interesting because they are largely immune to cancer and aging. Shar-Pei dogs are dogs with deeply wrinkled skin. Might they also be resistant to cancer? It looks like they are, indeed. However, sadly, Shar-Pei dogs are short lived due to other health problems.
  7. In England, more than half (57%) of those who die are older than 80.
  8. Australians show that you can wipe out disease-carrying mosquitoes using genetic engineering.
  9. A heart disease drug seems to be able to at least partially reverse Type 1 diabetes, in some cases:

    addition of once-daily oral verapamil may be a safe and effective novel approach to promote endogenous beta cell function and reduce insulin requirements and hypoglycemic episodes in adult individuals with recent-onset T1D.

    In related research, Omega-3 fatty acids could help with Type 1 diabetes.

  10. Though Siri and Alexa can understand what you are saying, most of the time, they cannot isolate your voice in a crowd of people talking. It is essentially an unsolved problem in speech recognition. It seems that some researchers made progress, bringing the error rate down from 90% to 30%, under some conditions. The problem remains unsolved (30% is high).