Daniel Lemire's blog

, 4 min read

Science and Technology links (June 16th, 2017)

How much bandwidth do we have? It seems that each of our eyes has 1 megabyte per second. That’s about 100GB per day assuming you close one of your eyes and you never sleep.

I found a fascinating article on “academic urban legends” including the myth that spinach is a good source of iron:

First, it falsified an idea that I had carried with me since I was a child, that spinach is an excellent source of iron. The most striking thing, however, was that a single decimal point, misplaced 80 years ago, had affected not just myself and my now deceased parents, but also a large number of others in what we place on our table.

(Read the whole article, it is not as simple as a decimal point.)
(via John D. Cook)

There is an app for the Apple Watch called cardiogram that is taking the wearers of the watch by storm:

Cardiogram uses the Apple Watch’s built-in heart sensor to give you advice about heart health — for instance, showing when you’re unusually stressed out by checking your heart rate.

I really need to get myself one of these watches!

As we age, we tend to lose muscle mass, to get weaker. The process is not entirely well understood, but it seems that it could be mediated at least in part by a loss of activity… As we age, we exercise less and this leads to detrimental changes in our metabolism. There is some hard evidence for this theory:

(…) we find that sedentary but not active humans display an age-related decline in the mitochondrial protein that is associated with muscle loss.

(via P. D. Mangan)

China just switched on the world’s largest floating solar power plant. It is still tiny (40MW) in comparison with many conventional power plants.

You can find melatonin at your local drug store or you can order it from Amazon. Many people take it at night to help them sleep. It seems that it could prevent neurological diseases. I sleep very well, so I am not tempted to take melatonin, but if I ever have trouble sleeping, I might quickly change my mind.

WordPress (the company) is shutting down its San Francisco office because employees never show up, preferring to work from home. I tend to work mostly from home myself, and I might never leave my home, except that I have graduate students and postdoctoral fellows to meet, and I am also department chair, so I have to show up for meetings from time to time. This being said, for programming or writing, I am far more productive at home. If I were a full-time programmer, I would certainly expect my employer to let me work from home. Somewhat ironically, it is part of my job to try to entice graduate students to show up to our lab.

When your skin gets red and your body aches, you are probably suffering from inflammation. It is a crude response from our immune system that helps us fight viruses and bacterias. We can suppress inflammation using something as simple as aspirin. However, inflammation is also involved in tissue repair. A recent paper shows that a protein that drives inflammation is critical for muscle regeneration. Perutz wrote in Nature:

The number of scientists in the biomedical field is growing exponentially (…)

Peter Rothman comments:

Contrary to some assertions, exponential advances in science and technology are not due to some fundamental law of nature but rather the exponential increase in the number of scientists doing science. (…) Biological research progress doesn’t generally scale with computer chip density although some specific areas might scale with available computational power. In other areas, you still need to spend a large number of hours in the lab actually doing the work.

Science, even medical science, is not homogeneous. Many areas of science advance at a breakneck speed, even when relatively few people are involved. Back in 2012, doing gene editing was science-fiction for most people, but today high school students can do it, affordably. Back a few years ago, advanced computing applications such as face recognition required a Ph.D. in the field and advanced mathematics… whereas today you can get it done in a few hours using free software libraries. Meanwhile, other research areas, like cancer research, remain painfully slow and expensive. What we hope is that the areas that make rapid progress can rescue the slow moving fields. This has happened time and time again in our history. That is, it would have been useless for the Roman Empire to try to build the Internet. No matter how much they would have invested, the progress would have been non-existent. However, the Roman Empire could have benefited greatly from an industrial revolution.

Senescent cells are “old” cells that won’t die. We now have the technology to kill them, albeit that’s not yet perfected to the point where your doctor can get rid of your senescent cells. What do senescent cells do? A lot of bad. A recent article shows that senescent cells drive the “fatty liver” disease.