Science and Technology links (July 1st, 2017)

Canada is 150 years old today.

The iPhone is 10 years old this year. We can safely say that the iPhone 7 is over a hundred times faster, in almost every way than the original iPhone. Very few things get 100 times better over 10 years. You have to improve the performance by 60% each and every year.

Though mammals like us can heal injuries, there is often scarring. Scarring should be viewed as imperfect healing. It is not just a matter of looks, scars make your tissues less functional. As far skin healing is concerned, scientists have found a way to cause skin to heal without scarring, at least in mice.

Essentially, we can manipulate wound healing so that it leads to skin regeneration rather than scarring, (…) the secret is to regenerate hair follicles first. After that, the fat will regenerate in response to the signals from those follicles. (…) regenerating fat cells in skin can be beneficial for conditions beyond scarring. The process could potentially become a new anti-aging treatment, as the formation of deep wrinkles is thought to result from permanent loss of skin fat.

It seems that fasting (going without food) could be a key to regenerating your immune system:

The study has major implications for healthier aging, in which immune system decline contributes to increased susceptibility to disease as people age. By outlining how prolonged fasting cycles  periods of no food for two to four days at a time over the course of six months  kill older and damaged immune cells and generate new ones, the research also has implications for chemotherapy tolerance and for those with a wide range of immune system deficiencies, including autoimmunity disorders.

Chimpanzees are not that much stronger than we are:

But now a research team reports that contrary to this belief, chimp muscles’ maximum dynamic force and power output is just about 1.35 times higher than human muscle of similar size, a difference they call “modest” compared with historical, popular accounts of chimp “super strength,” being many times stronger than humans.

Human beings are optimized for high endurance:

The flip side is that humans, with a high percentage of slow-twitch fibers, are adapted for endurance, such as long-distance travel, at the expense of dynamic strength and power. When we compared chimps and humans to muscle fiber type data for other species we found that humans are the outlier, suggesting that selection for long distance, over-ground travel may have been important early in the evolution of our musculoskeletal system

So how do you fight a chimpanzee? I would guess that getting the fight to last as long as possible is your best bet as a human being. The chimpanzee will get exhausted first. So I would probably either keep the chimpanzee at bay or run away. If the chimpanzee pursues, I would just wear him down.

A few weeks ago, there was an article in Nature claiming that human lifespan is limited to 115 years. There are very few of us that can hope to ever reach 115 years of age at the present time, but the question is whether it will change. Some people believe that 115 years of age is a hard limit that cannot be exceeded. Several scientists have now issued counterpoints. Siegfried Hekimi from McGill University (Montreal) says that…

You can show the data are compatible with many different trajectories and not at all an ongoing plateau (…) by extending trend lines, we can show that maximum and average lifespans could continue to increase far into the foreseeable future. (…) If this trend continues and our life expectancy of the average person becomes 100, the longest person might make it to 150 (…)

Jim Vaupel from the Max Planck Institute writes:

The evidence points towards no looming limit. At present the balance of the evidence suggests that if there is a limit it is above 120, perhaps much above  and perhaps there is not a limit at all.

Maarten Rozing from the University of Copenhagen writes about a biological clock limiting our lifespan:

We now know not only that the idea of such a clock is highly implausible, but also that ageing is proving to be more amenable to change than used to be supposed

The rebuttals can be found in Nature:

Of course, the real answer is at this point is that we do not know how long human beings could live. This being said, Yuval Noah Harari makes a compelling case in his book Homo Deus: A Brief History of Tomorrow that homo sapiens has reached the end of the line. Very solid arguments can be made that, say, in 100 years, there won’t be any homo sapiens left on the planet. So it is entirely possible that we will never find out how long homo sapiens could live.

Daniel Lemire, "Science and Technology links (July 1st, 2017)," in Daniel Lemire's blog, June 30, 2017.

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Daniel Lemire

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

2 thoughts on “Science and Technology links (July 1st, 2017)”

  1. Suppose I have a wound on the palm of my hand. Will I need to grow hair on the palm of my hand in order to avoid a scar? I think I’d rather have a scar.

    1. Suppose I have a wound on the palm of my hand. Will I need to grow hair on the palm of my hand in order to avoid a scar? I think I’d rather have a scar.

      One would hope that they would use this trick to study the necessary signalling. Then you could just apply some topical medication on your injury.

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