7th September 2019, 3 min read

Science and Technology links (September 7th 2019)

1. In a small clinical trial, scientists administered some “anti-aging” therapies to people between their fifties and sixties. They used growth hormone to regenerate the thymus, part of our immune system which is nearly all gone when people reach 50 years old. They complemented this therapy with anti-diabetes drugs (dehydroepiandrosterone and metformin) as an attempt to compensate for the fact that growth hormone is pro-diabetic. The researchers found that in a majority of the participants, the thymus was indeed regenerated: to my knowledge, this is a breakthrough in human beings (we only knew that in worked in animal models). Further, using an epigenetic clock, they found that participants’ biological age was reversed, by 2.5 years on average. The result persisted six months after stopping the trial. The surprising results should be viewed with caution given that it was a small trial with no control. Nevertheless, to my knowledge, it is the first time that biological aging has been reversed in human beings following a supervised therapy. The article is short and readable. (Source: Nature)
2. Researchers found out how to edit large pieces of DNA, making it potentially easier than before to construct synthetic genomes. (Source: Science)
3. Mathematician Hanna Fry on statin drugs:
   

Of a thousand people who take statins for five years, the drugs will help only eighteen to avoid a major heart attack or stroke.

1. Chronological aging (how many years you lived) and biological aging (loss of fitness with time) differ. There is apparently a tendency for human beings to biologically age slower. The trend was confirmed between 1988 and 2010. Older men benefited most from this trend. I do not think that we fully understand this phenomenon.
2. A woman received a cornea made from reprogrammed stem cells.
3. Drones are used in China to spray insecticides more efficiently than farmers can.
4. If you go Harvard University, you will have access to the best teaching and best professors, won’t you? Not so fast write Hacker and Dreifus:
   

At Harvard, even untenured asssistant professors get a fully paid year to complete a promotion-worthy book. Thus in a recent year, of its history department’s six assistant professors, only two were on hand to teach classes. In Harvard’s department of philosophy that same year, almost half of its full-time faculty were away on sabbaticals. Of course it was the students who paid. Many of their undergraduate courses were canceled or given by one-year visitors unfamiliar with the byways of the university.

Harvard undergraduate students give their professors C- on classroom performance.

1. Regarding anxiety, no psychological interventions had greater effects compared with placebo.
2. Men who are avid consumers of pornography are no more sexist or misogynistic than the general public. In fact, pornography users hold more gender egalitarian views.
3. A new drug was developed quickly using deep learning.
4. A software program can pass an 8th grade science test.
5. Our cells can replicate only so many times before their telomeres are too short. To keep on dividing, cells must use an enzyme called telomerase. It was believed until now that, except for cancer, most of our cells (somatic cells) did not use telomerase. It appears that this belief is wrong: when our cells have short telomeres, they will sometimes use telomerase to protect themselves.