Science and Technology links (August 24th, 2018)

  1. There is water on the surface of the Moon. This is important because if you want to build a long-term base on the Moon, having access to water is a great asset. Water can sustain life, but it can also be use to create fuel (e.g., hydrogen).
  2. Despite paying tens of thousands of dollars in tuition fees, despite being the very best students college have… a quarter of second-year medical students reported that they almost never attend class:

    Leaders in medical education have begun to scramble. Some medical schools, like Harvard, have done away with lectures for the most part.

    If you think that it is only medical students, it is not. A 2014 study found that Harvard students (some of the best and brightest) only have 60% attendance rate. That is, when you measure how often students attend classes in one of the best universities in the world, you find that 40% of the student skip any given class. That is despite the fact that some professors factor in class attendance in the grade.

  3. Some people associate crowded cities with poor living conditions. This is an incorrect intuition. Osaka (Japan) has a higher rating that Calgary in Canada. Calgary is a fantastic Canadian town, but it is not exactly crowded. Similarly, Toronto and Tokyo are tied as sone of the best cities in the world, despite having vastly different densities.
  4. John Ioannidis, a celebrated medical researcher, calls for us to stop using observational studies:

    Simply by observing what people eat and trying to link this to disease outcomes is moreover a waste of effort. These studies need to be largely abandoned. We’ve wasted enough resources and caused enough confusion, and now we need to refocus. Funds, resources and effort should be dispensed into fewer, better-designed, randomized trials.

    More formally, he writes:

    Some nutrition scientists and much of the public often consider epidemiologic associations of nutritional factors to represent causal effects that can inform public health policy and guidelines. However, the emerging picture of nutritional epidemiology is difficult to reconcile with good scientific principles.

    Archer et al. are equally critical:

    investigators engendered a fictional discourse on the health effects of dietary sugar, salt, fat and cholesterol when they failed to cite contrary evidence or address decades of research demonstrating the fatal measurement, analytic, and inferential flaws

    We are facing a serious problem: nutritional “science” is failing us. It is non-falsifiable, non-reproducible; it lacks rigour. It is “fake news”.

  5. With much fanfare, an article in the prestigious Lancet claims that “the level of consumption that minimises health loss is zero” using observational studies of alcohol use.Should you stop consuming alcohol if you do?

    First, we need to point out that these conclusions are based on observational studies. Some reputed scientists believe these studies are a waste of effort.

    Second, let us take the study at its words and assume that its conclusions are entirely correct. By their own reports, to experience one extra health problem, 25,000 people need to drink 10g of alcohol a day for a year. Or 1,600 people need to drink 20g of alcohol a day.

    Unless you drink far more than 20g of alcohol a day, you can be certain that alcohol is not going to kill you.

    David Spiegelhalter (a famous statistician) has a more in-depth analysis on his blog. He has other interesting blog posts including one where he demonstrates that drinking up to current guidelines linked to improved cognitive performance.

    Improved cognitive performance sounds good to me!

  6. Google’s Pixel 2 phone monitors music being played and automatically recognizes it. By itself, this is not impressive in 2018. What is more impressive is that this is done entirely using an onboard database residing on the phone.
  7. We can tell how “old” a cell is by how long its telomeres are. Telomere are the protective ends of chromosomes that grow shorter with each cell division, until the cell cannot divide anymore. Thankfully we can “rejuvenate” a cell using telomerase. Our cells normally do not use telomerase. Some cancers regularly use telomerase as well as stem cells. If your cells were to make more active use of telomerase, it can be argued that your cells would remain young. But some people fear that it might also make it more likely that you will die of cancer. In fact, some people believe that cell aging evolved to protect us from cancer. Yet there is not much evidence that it is the case, and rather more evidence that having short telomeres might increase your cancer rates. A recent study concludes once more than telomerase is safe:

    Given the potential cancer risk associated to telomerase expression in the organism, we set to analyze the effects of telomerase gene therapy in a lung cancer mouse model. Our work demonstrates that telomerase gene therapy does not aggravate the incidence, onset and progression of lung cancer in mice. These findings expand on the safety of AAV-mediated telomerase activation as a novel therapeutic strategy for the treatment of diseases associated to short telomeres.

    That is excellent news. We know how to administer telomerase. Telomerase extends the lifespan of mice.

  8. Clinical trials are supposed to be pre-registered. This means that ahead of time you must file in a report where you explain what you expect to find. Yet only about two-third of all clinical trials are pre-registered. Government and industrial trials are more likely the registered; academics are more likely to skip pre-registration. In effect, academics show less rigour.
  9. Rejuvenation of the brain via cell replacement to reverse age-related damage and functional decline appears to be as valid an approach as it is for most other organs and tissues.

Daniel Lemire, "Science and Technology links (August 24th, 2018)," in Daniel Lemire's blog, August 24, 2018.

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Daniel Lemire

A computer science professor at the University of Quebec (TELUQ).

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