The age of machine learning

It is not (yet?) the age of machines, but it is the age of machine learning.

That is, if we are to believe the science headlines of the past five years or so. Machine learning — I’ll use it here interchangeably with ‘narrow’ AI, which is not exactly correct, but makes for easier reading — has been making inroads into many fields.

Several recent machine learning advances are mentioned in some of my earlier posts.

(Warning: link fest! The previous posts I am referring to: general science and art, but also more specifically, the use of AI in historical research, genetic enhancement, mental health, aging research (including the development of ‘aging clocks’), video game ecology, Hollywood, astrobiology, epidemiology, stock markets, and the job market.) …

Protein, bro

Have you heard the latest magic word in dietville, fitnesstown, and healthcity? That’s right, protein. We’ve got everything, from protein ice cream to protein pizza, each of which comes with the promise of losing fat and building muscle. Magic, I tell you.

Or maybe it’s just good marketing.

Of course, protein is important (but you’re probably already getting enough of it). As one of the three macronutrients (besides carbohydrates and fats), protein fulfils a variety of functions in our bodies. Any fervent gym-goer will be able to tell you that protein is important for building muscle. …

Proverb, schmoverb

You can’t buy health.

Well, that’s not entirely or fully accurate. In some (many?) cases, you can.

Let’s try again.

Health is wealth.

Maybe. Sometimes. Perhaps.

Third time’s a charm?

Someone else’s health is wealth.

Aha, now we’re on to something.

But first, big caveat: health and disease are (in)famously nebulous concepts. These concepts can be shaped by culture, available pharmaceutics, and subjective experience. To keep things from becoming annoyingly complex, let’s define health as something like ‘a person’s pain-free ability to perform day-to-day actions with most biochemical parameters falling somewhere within the 95% interval of the bell curve describing each’s distribution across the population’. …

During the global pandemic, COVID-19 has been barreling through nursing homes. The number of infections and deaths there is staggering.

It’s easy to say in hindsight, but we should’ve seen this coming.

People of advanced age, often with underlying health conditions, living close together in the same building. A better target for COVID-19 couldn’t have been imagined.

Let’s make it worse, shall we? Nursing homes also tend to be understaffed. As a result, the staff is overworked. Add to that the fact that the necessary protective measures make the staff’s job even harder and time consuming, and the recipe for disaster is complete. And what if a staff member is infected. Stay home and make the work of their colleagues even harder? Come to work and risk infecting residents? …

Energy going down

Did you ever notice how most small children seem to have boundless energy? They sit down for a few minutes, then — bam! — running circles at full speed until their parents lose their minds and their breath.

And did you ever notice how people of old age seem to have little energy? The older we become, the more even doing nothing tires us.

(Of course, there are strong individual differences, hence my use of the word ‘most’ twice above. There are ten-year-old couch potatoes and eighty-year-old surfers.)

When we talk about energy in our bodies, we need to talk about the mitochondria, often called the ‘batteries’ or ‘energy factories’ in our cells. …

Cancer and humans

Following heart disease, cancer is the second leading cause of death worldwide (on global average, about 1 in 5 of us will have to face these rebellious cells). Cancer occurs when a cell begins to divide uncontrollably and foregoes the normal rules of growth and development.

(For a short story about the life of a cancer cell, check out ‘Divide and Conquer’.)

At its root, the cause of cancer is a collection of mutations. Mutations happen when something goes wrong with copying the DNA during cell division. (That doesn’t mean that all mutations are bad, but that’s another story.)

There are also external substances that cause mutations. Excessive exposure to UV light (such as blaring sunlight or, even worse, tanning beds) is strongly linked to an increased chance of developing skin cancer, and things such as air pollution and processed meat, are linked to lung cancer and colorectal cancer, respectively. Our gut microbiome influences cancer risk as well, and could even be leveraged to improve chemotherapy. …

Wine, peanut butter, and chocolate

Most kids, at some point, want to grow up (foolish, I know that now). But no one wants to grow old. After all, where’s the fun in feeling your body crumble?

So, since at least 4,000 BC, humanity has been on the lookout for the elixir of life. No success so far.

At the current state of knowledge, for all of us a declining immune system, increased risk for cancer increases, muscle loss, stiff joints, loose connective tissue, and a memory with increasing holes await.

Yet we remain undeterred in the quest for immortality (or at least a longer, healthy life). …

A CRISPR primer

The story of CRISPR’s development as gene editing tool begins in 1987. In that years, scientists identified specific DNA sequences in bacteria.

These DNA sequences are short, clustered together, the same if you read them from front to back or back to front (palindromic), repeated, and regularly interrupted by other DNA chunks. Hence, CRISPR: clustered regularly interspaced short palindromic repeats.

Twenty years later, researchers figured out that CRISPR sequences are important parts of bacterial immune systems and protect bacteria against repeated virus infections. The bacteria become able to quickly recognize a second infection by a virus through integrating bits of virus DNA (from the first infection) into their genome. …