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Showing posts from July, 2018

Childhood Adversity and Brain Development

Stress in early childhood produces a flood of glucocorticoids that permanently damages brain development, resulting in impaired cognition and emotional regulation.
Thus, childhood adversity can atrophy and blunt the functioning of the hippocampus and frontal cortex. But it’s the opposite in the amygdala— lots of adversity and the amygdala becomes larger and hyperreactive. One consequence is increased risk of anxiety disorders; when coupled with the poor frontocortical development, it explains problems with emotion and behavior regulation, especially impulse control.  Sapolsky, Robert M.. Behave: The Biology of Humans at Our Best and Worst (p. 251). Penguin Publishing Group. Kindle Edition.  The worst stressor seems to be an abusive mother, or being separated from the mother at an early age, but all sorts of other adversity (poverty, lead poisoning, etc.) seem to have similar results.

Big Brains

Humans have relatively big brains - even modern humans with our brains 25% smaller than that of a Neandertal.  Our eighty-six billion or so neurons sounds impressive compared to a fruit fly's 250,000, but maybe not so much so compared to the honeybee's roughly 1 million.  After all, we weigh about a million times as much as a honeybee, but our neuron count is less than 100,000 times larger.  So who's the real brainiac?  On an absolute size scale, our brains and neuron count are dwarfed by the brains of elephants and whales.  Numerous birds best us on the brain size to body size scale, as do many primates.

So why are we driving all them and perhaps ourselves to extinction, instead of vice-versa?  The answer probably lies in our exceptional capabilities to cooperate and in our technology.  Of course ants and bees are at least equally good at cooperation, but they are too small to control fire.  Fire is not available to whales either.

Fugget About It

In addition to remembering stuff, our brains are busy forgetting about other stuff.  It turns out that forgetting is not a purely accidental process, its an active process, pruning the memory collection.  Memories deemed useless, obsolete or significantly redundant are actively suppressed.  Interestingly enough, these processes seem to be essentially the same in the 250,000 neuron fruit-fly brain and our own with roughly 86 billion neurons.

This process is discussed in Spolsky's Behave, a book I've been reading and writing about lately, but some new research is featured in Quanta here.
One form of active forgetting that scientists formally identified in 2017is called intrinsic forgetting. It involves a certain subset of cells in the brain — which Ronald Davis and Yi Zhong, who wrote the paper that introduced the idea, casually call “forgetting cells” — that degrade the engrams in memory cells. There are others.  It seems that at least initially, memories are merely suppressed r…

Choosing

Steve Hsu has been considering correlations between a polygenic index and college completion rate.  It appears that the genes are rather predictive of college completion.  Steve constructs this scenario:
You are an IVF physician advising parents who have exactly 2 viable embryos, ready for implantation. The parents want to implant only one embryo.  All genetic and morphological information about the embryos suggest that they are both viable, healthy, and free of elevated disease risk.

However, embryo A has polygenic score (as in figure above) in the lowest quintile (elevated risk of struggling in school) while embryo B has polygenic score in the highest quintile (less than average risk of struggling in school). We could sharpen the question by assuming, e.g., that embryo A has score in the bottom 1% while embryo B is in the top 1%.

You have no other statistical or medical information to differentiate between the two embryos.

What do you tell the parents? Do you inform them about the polyg…

Neural Adolescence

Humans have achieved 85% of adult brain volume by age two, but the brain is not fully "wired" until the mid-twenties, long after sexual and other physical maturity.  This has important consequences. Think about this— adolescence and early adulthood are the times when someone is most likely to kill, be killed, leave home forever, invent an art form, help overthrow a dictator, ethnically cleanse a village, devote themselves to the needy, become addicted, marry outside their group, transform physics, have hideous fashion taste, break their neck recreationally, commit their life to God, mug an old lady, or be convinced that all of history has converged to make this moment the most consequential, the most fraught with peril and promise, the most demanding that they get involved and make a difference. In other words, it’s the time of life of maximal risk taking, novelty seeking, and affiliation with peers. All because of that immature frontal cortex. Sapolsky, Robert M.. Behave: …

Slow Burn

While temperatures around the world are setting record highs, wildfires, and killing vulnerable people, the Arctic is having a relatively slow melt year.  No doubt this will be seized on by the usual suspects to "prove" that the long promised "recovery" is here, all the larger melts (at this point) are from the last eleven years, so it surely looks a lot more like a fluctuation.

ET - Where Are You?

The second most famous idea in extraterrestrial biology is the Drake Equation.  The idea of the Drake Equation is to express the probability of finding ETs as a product of presumably independent factors (fraction of stars with planet, fraction of planets suitable for life, probability of life arising on a suitable planet, etc.)  When the equation was first written down, none of these factors were known.  We now know that planets are common - there are many billions in our galaxy and perhaps trillions.  We can't be sure yet, but it looks like something like a billion ought to be broadly suitable for life.

The fact that life arose nearly as soon as it possibly could have on Earth suggests but doesn't prove that life is likely to arise on suitable planets.  Experimental biophysics and biochemistry seem to be converging on an explanation of how life arose one Earth, but large - enormous - uncertainties remain.  Much of this uncertainty could be removed if we were to find other lif…

Are The Robots Still Coming?

Today's US economy is robust by almost any standard.  Unemployment is very low and help wanted signs are plentiful.  So is concern about robots taking everybody's job overblown?  Well, maybe, so far.

On the other hand, wages are barely rising, which is nice for employers but not so much for workers.  This is surprising in a red hot economy.  So what is going on?

There are a few possibilities.  The great recession of 2007-2010 left a huge pool of discouraged workers who were not even trying to find work and who are just now entering the labor pool.  International competition continues to put downward pressure on jobs.  Also, automation of many traditionally high-pay factory jobs means that increased production doesn't automatically boost average pay.  Jared Bernstein, writing in the NYT, finds another reason: 40 years of Republican and corporatist suppression of organized labor.

Unsurprisingly, traditionally low paying jobs like food service have been slower to automate.  I…

Bend it Like Ronaldo

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Fernando has asserted that Ronaldo wasn't good at bending balls over opponents, and in fact usually shot under jumping opponents.  Nope.  I've looked at all 60 Ronaldo free kick goals.  Most are over.  Many are around or through or off deflections.  Maybe five could be considered under, but make your own count: here they are.


Why Cops Shoot Unarmed Black People

It's a tragically familiar scenario: a policeman stops a black person, they reach for wallet and driver's licence, or for their cell phone, and get shot to death.  Why does that happen, and what can we do about it?

The policeman's best defense might be "my amygdala made me do it." The brain has at least two circuits for processing threats.  In the first, the information goes to the amygdala, a threat is registered, and sent to the prefrontal cortex for further processing.  There the threat is evaluated and instructions are sent to the motor neurons for a response.  In the second, the alarms that go off in the amygdala are so strong that prefrontal processing is skipped, and the motor neurons are activated immediately, saving roughly 700 milliseconds.  The penalty for speedy evaluation is loss of accuracy: that cell phone or wallet might be evaluated as a gun.  This kind of fatal error probably happens more to blacks because policemen - even black policemen - find…

Whom?

The equilibrium or balance, so to speak, between his intellectual faculties and animal propensities, seems to have been destroyed. He is fitful, irreverent, indulging at times in the grossest profanity (which was not previously his custom), manifesting but little deference for his fellows, impatient of restraint or advice when it conflicts with his desires, at times pertinaciously obstinate, yet capricious and vacillating, devising many plans of future operations, which are no sooner arranged than they are abandoned in turn for others appearing more feasible.  Sapolsky, Robert M.. Behave: The Biology of Humans at Our Best and Worst (pp. 70-71). Penguin Publishing Group. Kindle Edition.  Phineas Gage, after having a 13 pound iron tamping rod blown through his skull in a blasting accident.  What is DT's excuse?

The Child Psychopath

Psychopathy seems to manifest itself early in childhood - perhaps as early as two or three, according to this article in The Atlantic by Barbara Bradley Hagerty.  The term of art for these children is "callous and unemotional child," partly because nobody wants to label young children with such a sinister diagnosis and partly because some of them seem to grow out of it or at least become functional adults.  The cause is unknown but there are clear physical and physiological correlates to go along with the behavioral traits.
The first abnormality appears in the limbic system, the set of brain structures involved in, among other things, processing emotions. In a psychopath’s brain, this area contains less gray matter. “It’s like a weaker muscle,” Kiehl says. A psychopath may understand, intellectually, that what he is doing is wrong, but he doesn’t feel it. “Psychopaths know the words but not the music” is how Kiehl describes it. “They just don’t have the same circuitry.” They …

Property and Collectivism

Let me argue a couple of somewhat unpopular propositions.

1)Property is the greatest restriction on commerce ever invented.  Aside from spouses, children, and what a person could carry, property emerged with farming and agriculture.  It was a necessary invention, since without a claim on the produce of farming, no one could be persuaded to undertake the vast labor entailed in planting and tending animals.  It was also the foundation of inequality though, since ownership of land isn't infinitely divisible if farming is to be practical.  One probably can't say that war first occurred with farming, but it, with the increased fecundity it enabled, produced more mouths than could be fed, and made it urgent to get more land by stealing somebody else's.  Like other restrictions on commerce, property probably decreased net (biological) efficiency, but in this case reserved more of it for human consumption.

2)The corporation is one of the most successful collectivist inventions.  O…

Why Not Free Trade?

I previously mentioned the big reason for free trade: economic efficiency.  Let me mention some types of restriction and the reasons for them.  One obvious one is the protection of so-called intellectual property.  In truly free trade, pirated software (movies etc) would pass unrestricted through international barriers, and so would dangerous products like terrorist bombs, banned drugs and weapons, unsafe pharmaceuticals, and technologies crucial for dangerous weaponry.

Another big and important reason for justifying trade restrictions is promotion of domestic industries.  The so-called Asian Tigers, from Japan to China, all built their industrial and technological bases by restricting foreign imports.  So did the United States 200 years ago.  Tariffs can promote local capital accumulation at the cost of local consumption.

Most of these types of restrictions on trade are aimed at promoting the competitive position or safety of the nation and its population.  Economists, who naturally …

Time to Slam the Door on Cryptocurrencies?

The revelation that the GRU used cryptocurrencies to facilitate and hide their hacking into the US 2016 election is one more reason to consider shutting them down.  Cryptocurrencies exist because some clever computer guys figured out how to use cryptographic principles to hide transactions.  Unfortunately, the principle applications are criminal: money laundering, tax evasion, and financing illegal operations like spying, sabotage, and terrorism.

There are a variety of good reasons why governments seized control of money, and we now have some more.  Aside from the previously mentioned benefits, banning them would save hella electricity.

Free Trade

Most economists like free trade for a very simple reason: other things being equal, it leads to production and delivery of the most goods at the lowest cost.  A lot of other people don't like free trade, mostly merchants and manufacturers who would prefer less competition.  They also are pretty good a mobilizing their own workers, who also don't want competition.  Perfect free trade is an ideal, never perfectly achieved, but until Donald Trump took a  wrecking ball to international trade, the world had approximated it probably more closely than ever before.

Adam Smith's The Wealth of Nations could be considered the founding document of modern capitalism, and Smith was a strong advocate of free trade, but even he noted some exceptions.  Aside from the parochial interests noted above, there are other objections to completely free trade.  More stuff for everybody is nice, but anyone with a knowledge of history or biology knows that you need more than that to survive.  Smith m…

No Salvation

I recently watched a few episodes of the television show Salvation, a science fiction, disaster thriller with soap opera overtones.  It's a Deep Impact knock-off - MIT grad student discovers asteroid headed for Earth, improbable conspiracies of silence are revealed, beautiful people fall into bed with each other.

I know that appreciating this sort of thing requires a big effort at suspension of disbelief, and I was prepared to ignore to ignore giant plot holes, the grad student's attempts to solve the 3-body problem using "gravimetric data" (WTF?), and the Elon Musk type inventor demanding and getting billions to develop a Newton's Third Law violating EM drive, but they managed to break me anyway.

The last straw was the arrogant and pig-headed government scientist (all the scientists here are dull, arrogant, pig-headed, and spend a lot of time saying "you're insane," mostly to the Elon Musky guy) declaring that they would crash a Jupiter probe into …

Too Good

Croatia was just a it too good for England.  England could neither defend its early lead or capitalize on several good chances.  Croatia consistently played with more energy and was much better at holding the ball.  Way too many bad giveaways for England.

France looks better, but who knows now?

France

France has got to be the world cup favorite now, but it certainly did not look overpowering against Belgium.  In fact, if the ref hadn't missed two obvious fouls just outside the penalty box, the result might have been rather different.  Belgium's stars missed some clear chances too.

Holy Water

Apparently the Hindu Nationalist government of India is promoting the "discovery" of the ancient river that features strongly in the Vedas, the Saraswati.  They claim to have found its ancient course and have dug some ditches and holes, finding groundwater.  Some are promoting this water as a universal cure all.  Hindu Nationalism is deeply tied the mythology of the Hindu religion, and deeply invested in some rather credulous interpretations of those myths.

The attachment to religious mythology is convenient since it permits unlimited glorification of the accomplishments of Indian civilization in the past, including the invention of agriculture and even nuclear weapons in ancient times.  It also fosters a festering resentment of India's place in the world today.  To an outsider, this seems silly.  The very real and verified accomplishments of Indian civilization, in literature, mathematics, technology and philosophy are enough for any nation to be proud of.  Conjuring up…

Astro FOTD: Why Are Galaxies Spirals?

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The spiral galaxies like M31 (Andromeda) and our own Milky Way are among the most beautiful objects in the sky.  OK, we can't really see the shape of our own galaxy very well due to being in it, but I'm sure that it's wicked awesome.  What gives them their shape is their spin, and the fact that angular momentum is conserved.  So why do they spin?



Before trying to answer that, I should point out that not all galaxies do spin, at least not enough to give them that disk-like or spiral shape.  Many galaxies, including the very biggest ones, are ellipticals, and some of them have almost no spin, with the motions of their stars very nearly random.

Galaxies are believed to have formed quite early in the history of the universe when ordinary matter, having cooled enough for the electrons and nuclei to condense into neutral atoms, fell into the gravitational potential wells formed by dark matter out of primordial fluctuations, forming clouds of hydrogen and helium of about a trilli…

You're a Queer One, Jimmy Jordan*

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Jim Jordan, attack dog for Trumpistan and possible candidate for Speaker of the House, has run into a bit of flak on his own history.  Jordan is famous for his attacks on the Department of Justice, Robert Mueller, Rod Rosenstein, and any other threat to the Trump-Putin love fest.  He's not especially bright, but he is a real asshole, at least in his Committee hearings.

His problem is that he spent 8 years as an assistant wrestling coach at Ohio State, when, as has been revealed, the team was mired in a "cesspool of sexual deviancy and molestation" led by two team doctors.  Jordan has denied knowing anything about it, but several team members have now called him a liar.

William Saletan points out that even if what he now claims were true, his own standards in attacking his foes condemn him.  Item 1 of several:

1. You’re responsible for what happens on your watch. In 2013, Jordan berated then-FBI Director Robert Mueller for not knowing details about an FBI investigation of t…

Free Willy

Sabine H. is thinking about free will again.  I tend to be suspicious of such endeavors, mainly because I have no idea what she, or any of the philosophically inclined,  mean by the concept.  If I understand her, she thinks will can't be free if the outcomes of decision making are determined either randomly or by deterministic physical processes.  She thinks there might be an exception if the decision functions have a "singularity" beyond which they can't be continued.  Some think that some solutions of the Navier-Stokes equations might have this character.

My personal approach is that she has defined "free will" out of existence.  Most of us have no trouble distinguishing between things we do that are done under compulsion from those that are freely chosen.  If you imagine a universe that has only deterministic and random things in it, then will and decisions will be built out of those elements.

Suppose you imagine some transcendent entity that is unbound …

Bad Actor: Hamming it Up

A classic error of the beginning actor is "overselling the event."  The World pretty much agrees that Neymar is a superb soccer player, but a bunch of acting coaches say that he's a pretty bad actor.  His antics after getting stepped on didn't just offend football fans.  I personally hoped that the referee would take out a gun and shoot him, just to put the poor lad out of his misery.  No staged death scene in my memory has been so pathetic or ridiculous.

After a hard tackle, he rolled over so many times that I thought that he might be auditioning for a role as hedgehog croquet ball in Alice in Wonderland.

Democratic Socialism and Capitalism

Alexandria Ocasio-Cortez shocked her establishment Democratic opponent with her victory and also disturbed the Zeitgeist by proclaiming herself a Democratic Socialist.  So far as I can tell, the Democratic Socialist program is warm, fuzzy and vague.  Some purported details:
Today, thousands of DSA members across the country are organizing for Medicare for All, rent control, abolishing ICE, a federal jobs guarantee, tuition-free college, free and legal abortions, a fighting labor movement, and ending police violence and mass incarceration, climate devastation, and war. For me, some of these ideas are good (Medicare for All, tuition-free public colleges, legal abortions, addressing climate change), some are bad (rent control, abolishing ICE), some are highly problematic (federal jobs guarantee) and others hopelessly unrealistic (ending police violence and war).  I would like to see a stronger labor movement (but fighting won't help), curbs on police violence, and far less incarcerati…

Where is James Bond Now that Britain Really Needs Him?

Trump's favorite terrorist seems to have poisoned another couple of Brits, perhaps unintentionally.  I expect Britain to wring its hands, pout, and impose some symbolic sanctions.  Would M have had a better idea?  Something like whacking a couple of P's oligarchical buddies, while spreading rumors that they had had a falling out with the big dog?

First We Kill All the Venezuelans ...

We read that Trump was eager to invade Venezuela. While this would likely have gratified Fernando, I doubt that Venezuelans would have appreciated it much - there is nothing quite like a foreign invasion to unify a people. Doubtless the conflict would have attracted every leftist on the continent, killed thousands or hundreds of thousands of Venezuelans, and gotten a lot of US embassies burned, but installing a right-wing pro-US government might have been a lot tougher.

On the plus side, it probably would have gotten Trump impeached.

Caste, Class and Social Hierarchy

It's a curious fact that agricultural societies, unlike hunter-gathering societies, have nearly always been hierarchical. In Wikipedia's definition, Caste is a form of social stratification characterized by endogamy, hereditary transmission of a lifestyle which often includes an occupation, status in a hierarchy, customary social interaction, and exclusion.[1][2] Although caste systems exist in various regions, its paradigmatic ethnographic example is the division of Indian society into rigid social groups, with roots in India's ancient history and persisting until today; Indian society has long been divided into thousands or perhaps tens of thousands of endogamous castes called jati. These are very ancient, with at least some jati having practiced endogamy for 2000 years or more. While India is the most famous example, rather analogous institutions exist or did exist very widely. Certain castes in Ethiopia appear to be twice as old (4000 years) according to genetic…

Spain vs. Russia

It would be hard to argue that the best team won, but by the end, Russia felt like the most deserving team. (1-1 game, 4-3 Russia on tiebreak penalties). I found it weirdly gratifying that Spain's strategy of boring Russia and us to death failed. I imagine that the results would have been rather different if my formula for resolving ties with 7 v. 7 play had been followed. The last save was amazing.