Friday, May 6, 2016

Quote of the Day

What propels an embryo from one stage to the next-and makes one species different from another-is not a blueprint but rather an enormous autonomous library of the instructions contained within its genome. Each gene does double duty, specifying both a recipe for a protein and a set of regulatory conditions for when and where it should be built. Taken together suites of these IF-THEN genes give cells the power to act as parts of complicated improvisational orchestras. Like real musicians, what they play depends on both their own artistic impulses and what the other members of the orchestra are playing. As we will see in the next chapter, every bit of this process-from the Cellular Big 4 to the combination of regulatory cues-holds as much for development of the brain as it does for the body.

- Gary Marcus, The Birth of the Mind: How a Tiny Number of Genes Creates The Complexities of Human Thought

Thursday, May 5, 2016

What I've Been Reading

Thousands of years after Aristotle’s seminal work on causality, hundreds of years after Hume gave us two definitions of it, and decades after automated inference became a possibility through powerful new computers, causality is still an unsolved problem. Humans are prone to seeing causality where it does not exist and our algorithms aren’t foolproof. Even worse, once we find a cause it’s still hard to use this information to prevent or produce an outcome because of limits on what information we can collect and how we can understand it. After looking at all the cases where methods haven’t worked and researchers and policy makers have gotten causality really wrong, you might wonder why you should bother.
          […]
Rather than giving up on causality, what we need to give up on is the idea of having a black box that takes some data straight from its source and emits a stream of causes with no need for interpretation or human intervention. Causal inference is necessary and possible, but it is not perfect and, most importantly, it requires domain knowledge.
Why: A Guide to Finding and Using Causes by Samantha Kleinber. Beautiful book, full of insights  not only for ML/AI aficionados but also to anyone who want to improve their knowledge about the world around them.

The main thing is to realize is that there is not just one method for all causal inference problems. None of the existing approaches can find causes without any errors in every single case (leaving out lot of opportunities for research). Some make more general claims than others, but these depend on assumptions that may not be true in reality. Instead of knowing about one method and using it diligently for every problem you have, you need a toolbox. Most methods can be adapted to fit most cases, but this will not be easiest or most efficient approach.

Given that there is not one perfect method, possibly the most important thing is to understand the limits of each. For instance, if your inferences are based on bivariate Granger causality, understand that you are finding a sort of direct correlation and consider the multivariate approach. Bayesian networks may be a good choice when the casual structure (connection between variables) is already known and you want to find its parameters (probability distribution) from some data. However, if time is important for the problem, dynamic Bayesian networks or methods that find the timing of casual relationships from the data may be more appropriate. Whether you data are continuous or discrete will narrow down your options, as many methods handle one or the other (but not both). If the data include large number of variables or you do not need the full structure, methods for calculating casual strength are more efficient than those that infer models.  However, when using these consider whether you will need to model interactions between causes to enable prediction. Thus causes are used for is as important as the available data in determining which methods to use. And finally, recognize that all the choices made in collecting and preparing data affect what inferences can be made. 


Quote of the Day

We have to change truth a little, in order to remember it.

- George Santayana

Wednesday, May 4, 2016

Quote of the Day

It’s not unusual for experts to totally miss the point of Ramanujan’s formulae. That happens over and over again. Everyone has four or five favorite examples when they’ll say, ‘I thought I understood this formula. I wrote papers on it, only to discover, five years later, that I’d missed the point.

- Ken Ono

Tuesday, May 3, 2016

In Celebration of Being Alive

More and more, as I near the end of my career as a heart surgeon, my thoughts have turned to the consideration of why people should suffer. Suffering seems so cruelly prevalent in the world today. Do you know that of the 125 million children born this year, 12 million are unlikely to reach the age of one and another six million will die before age of five? And, of the rest, many will end up as mental or physical cripples.

My gloomy thoughts probably stem from an accident I had few years ago. One minute I was crossing the street with my wife after a lovely meal together, and the next minute a car hit me and knocked me into my wife. She was thrown into the other lane and stuck by a car coming from the opposite direction.

During the next few days in the hospital I experienced not only agony and fear but also anger. I could not understand why my wife and I had to suffer. I had eleven broken ribs and a perforated lung. My wife had badly fractured shoulder. Over and over, I asked myself, why should this happen to us? I had work to do, after all; there were patients waiting for me to operate on them. My wife had a young baby who needed her care.

My father, had he still been alive, would have said: “My son, it is God’s will. That’s the way God tests you. Suffering ennobles you- makes you a better person.”

But as a doctor, I see nothing noble in a patient’s thrashing around in a sweat-soaked bed, mind clouded in agony. Nor can I see any nobility in the crying of a lonely child in a ward at night.

I had my first introduction to the suffering of children when I was a little boy. One day my father showed me a half-eaten, mouldy biscuit with two tiny tooth marks in it. And he told me about my brother, who had died several years earlier. He told me about the suffering of this child, who had been born with an abnormal heart. If he had been born today, probably someone could have corrected that heart problem, but in those days they didn’t have sophisticated heart surgery. And this mouldy biscuit was the last biscuit my brother had eaten before his death.

As a doctor, I have always found the suffering of children particularly heartbreaking- especially because of their total trust in doctors and nurses. They believe you are going to help them. If you can’t they accept their fate. They go through mutilating surgery, and afterwards they don’t complain.

One morning, several years ago, I witnessed what I call the Grand Prix of Cape Town’s Red Cross Children’s Hospital. It opened my eyes to the fact that I was missing something in all my thinking about suffering – something basic that was full of solace for me.

What happened there that morning was that a nurse had left a breakfast trolley unattended. And very soon this breakfast trolley was commandeered by an intrepid crew of two- a driver and a mechanic. The mechanic provided motor power by galloping along behind the trolley with his head down, while the driver, seated on the lower deck, held on with one hand and steered by scraping his foot on the floor. The choice of roles was easy, because the mechanic was totally blind and the driver had only one arm.

They put on quite a show that day. Judging by the laughter and shouts of encouragement from the rest of the patients, it was much better entertainment than anything anyone puts on at the Indianapolis 500 car race. There was grand finale of scattered plates and silverware before the nurses and ward sister caught up with them, scolded them and put them back to bed.

Let me tell about these two. The mechanic was all of seven years old. One night, when his mother and father were drunk, his mother threw a lantern at his father, missed and the lantern broke over the child’s head and shoulders. He suffered severe third-degree burns on the upper part of his body, and lost both his eyes. At the time of the Grand Prix, he was a walking horror, with a disfigured face and a long flap of skin hanging from the side of his neck to his body. As the wound healed around the neck, his jaw became gripped in a mass of fibrous tissue. The only way this little boy could open his mouth was to raise his head. When I stopped by to see him after the race, he said, “You know, we won.” And he was laughing.

The trolley’s driver I know better. A few years earlier I had successfully closed a hole in his heart. He had returned to the hospital because he had a malignant tumor of the bone. A few days before the race, his shoulder and arm were amputated. There was little hope of recovering. After the Grand Prix, he proudly informed me that the race was a success. The only problem was that the trolley’s wheels were not properly oiled, but he was a good driver, and he had full confidence in the mechanic.

Suddenly, I realized that these two children had given me a profound lesson in getting on with the business of living. Because the business of living is joy in the real sense of the word, not just something for pleasure, amusement, recreation. The business of living is the celebration of being alive.

I had been looking at suffering from the wrong end. You don’t become a better person because you are suffering; but you become a better person because you have experienced suffering. We can’t appreciate light if we haven’t known darkness. Nor can we appreciate warmth if we have never suffered cold. These children showed me that it’s not what you’ve lost that’s important. What is important is what you have left.


In Celebration of Being Alive,  Dr. Christian Bernard


Quote of the Day

It was not the feeling of completeness I so needed, but the feeling of not being empty.

- Jonathan Safran Foer

Monday, May 2, 2016

Quote of the Day

Ask the experimenters why they experiment on animals, and the answer is: "Because the animals are like us." Ask the experimenters why it is morally okay to experiment on animals, and the answer is: "Because the animals are not like us." Animal experimentation rests on a logical contradiction.


Charles R. Magel

Sunday, May 1, 2016

Quote of the Day

The difference between the poet and the mathematician is that the poet tries to get his head into the heavens while the mathematician tries to get the heavens into his head.

- G.K. Chesterton

Saturday, April 30, 2016

Wisdom Of The Week

Make no mistake: I am not suggesting that liberals adopt a fuzzy, gentler version of their politics. I am not suggesting they compromise their issues for the sake of playing nice. What I am suggesting is that they consider how the issues they actually fight for have drifted away from their egalitarian intentions.

I am suggesting that they notice how hating and ridiculing the people they say they want to help has led them to stop helping those people, too.

I am suggesting that in the case of a Kim Davis, liberalism resist the impulse to go beyond the necessary legal fight and explicitly delight in punishing an old foe.

I am suggesting that they instead wonder what it might be like to have little left but one's values; to wake up one day to find your whole moral order destroyed; to look around and see the representatives of a new order call you a stupid, hypocritical hick without bothering, even, to wonder how your corner of your poor state found itself so alienated from them in the first place. To work with people who do not share their values or their tastes, who do not live where they live or like what they like or know their Good Facts or their jokes.

This is not a call for civility. Manners are not enough. The smug style did not arise by accident, and it cannot be abolished with a little self-reproach. So long as liberals cannot find common cause with the larger section of the American working class, they will search for reasons to justify that failure. They will resent them. They will find, over and over, how easy it is to justify abandoning them further.They will choose the smug style.

Maybe the cycle is too deeply set already. Perhaps the divide, the disdain, the whole crack-up are inevitable. But if liberal good intentions are to make a play for a better future, they cannot merely recognize the ways they've come to hate their former allies. They must begin to mend the ways they lost them in the first place.


- The smug style in American liberalism

Quote of the Day

The technocratic illusion is that poverty results from a shortage of expertise, whereas poverty is really about a shortage of rights. The emphasis on the problem of expertise makes the problem of rights worse. The technical problems of the poor (and the absence of technical solutions for those problems) are a symptom of poverty, not a cause of poverty. This book argues that the cause of poverty is the absence of political and economic rights, the absence of a free political and economic system that would find the technical solutions to the poor’s problems. The dictator whom the experts expect will accomplish the technical fixes to technical problems is not the solution; he is the problem.

William Easterly, The Tyranny of Experts: Economists, Dictators, and the Forgotten Rights of the Poor