Daniel Lemire's blog

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Science and Technology links (September 2 2023)

  1. Physicists have a published a paper with 5154 authors. The list of authors takes 24 pages out of the 33 pages. The lesson is that if someone tell you that they have published an important paper, you should ask how many authors there were and what their exact role was.
  2. Vegatarians are at higher risk for hip fracture.
  3. Virgin Galatic brings private customers to space.
  4. Quercetin, a commonly available supplement, appears to reduce blood pressure and improve the lipid profile in human beings. (Quercetin is relatively expensive in Canada.)
  5. Scientists increasingly talk with certitude, they increasingly avoid words such as might or probably. It seems that it might be part of an effort to promote the research. In effect, science writing might be adapting strategies from marketing.
  6. I have long accepted the fact that if you encourage students to think that they can grow their abilities by hard work, they will better results. Macnamara and Burgoyne find that this result may not hold:

We conclude that apparent effects of growth mindset interventions on academic achievement are likely attributable to inadequate study design, reporting flaws, and bias.

  1. Heterochronic parabiosis is the process by which you connect the blood vessels of old and young animals (typically mice). Researchers ran a heterochronic parabiosis experiment over a long period of time (3 months) and they found that the old mice that have benefited from heterochronic parabiosis lived longer than control old mice. Furthermore, the treated old mice appeared rejuvenated, and the rejuvenation was still visible two months after the treatment. It seems that heterochronic parabiosis made the old mice younger at the level of gene expression. The approach is unlikely to be used on human beings as is. You would not want to connect the blood vessels of young human beings and old human beings for extended periods of times. However, it is a proof of principle. It seems that you can rejuvenate old animals by acting on the composition of their blood.
  2. Researchers used young blood plasma from pigs to seemingly rejuvenate old rats.
  3. A specific compound, AOH1996, appears to selectively kill cancer cells without side effect:

We report a small molecule inhibitor, AOH1996, of a cancer-associated isoform of PCNA (caPCNA), which notably, almost completely inhibits the growth of xenograft tumors without causing any discernible toxicity to experimental animals. (Gu et al., 2023)

  1. Old people tend to become frail, a process called sarcopenia. Though the most obvious effect is a loss of muscle mass, the muscle quality is also decreased. It is possible that the loss of muscle might a consequence of a loss of nerves in the muscles. Tezze et al. (2023) find that metformin and galantamine treat sarcopenia in old mice. Galantamine has been used to treat some of the side effects of Alzheimer’s whereas metformin is routinely used to treat diabetes.
  2. It seems that a significant fraction (e.g., 40%) of the measured warming in the recent decades could be explained by the urban effect: thermometers that were once located in the country become surrounded by a warm city.
  3. Naked mole rates are nearly ageless, they don’t age the way we do. Researchers have transfered a gene from naked mole rates to mice and found that they were able to increase the longevity of mice.
  4. The placebo effect is the phenomenon where people who receive a bogus treatment get better, despite the lack of actual drug. Two doctors (Hróbjartsson and Gøtzsche) suggest that there is not much of placebo effect outside small effect in the context of pain management.
  5. The number of natural disasters is not increasing.
  6. Used coffee grounds make strong concrete.
  7. China restricts how long young people can play video games. Their policies appear to be ineffectual: young people in China still play a lot of video games.
  8. Aging is conserved across mammalian species at select regions of the DNA. Thus if we rejuvenate some animals at the gene expression level, it is credible that it could extend to other animals.
  9. Psychiatrists choosing a treatment for themselves predominantly selected a different treatment than the one recommended to patients by participants asked in the regular recommendation role. Psychiatrists preferred the lless invasive options for themselves (i.e. watchful waiting) whereas they recommended the more invasive ones for the patient (i.e. antidepressants and depot injections).