Bill’s comment on my previous post reminded me of a book I read a few years ago, Aging With Grace by David Snowdon. The author describes what he learned about aging and especially about Alzheimer’s disease by studying a community…
Monthly Archives: June 2008
Brain plasticity
Today’s Big Ideas podcast carried a lecture by Norman Doidge on neuroplasticity, the recently-discovered ability of the brain to rewire itself. Doidge relates several amazing stories of people who have recovered from severe strokes or other brain injuries by developing detours around the…
Tips for using regular expressions
Jeff Atwood just posted a good article on regular expressions. Not the syntax of regular expressions but rather the strategy of when and how to use them.
Wine, Beer, and Statistics
William Gosset discovered the t-distribution while working for the Guinness brewing company. Because his employer prevented employees from publishing papers, Gosset published his research under the pseudonym Student. That’s why his distribution is often called Student’s t-distribution. This story is fairly well…
Two definitions of expectation
In an introductory probability class, the expected value of a random variable X is defined as where fX is the probability density function of X. I’ll call this the analytical definition. In a more advanced class the expected value of…
Why computer scientists count from zero
In my previous post, cohort assignments in clinical trials, I mentioned in passing how you could calculate cohort numbers from accrual numbers if the world were simpler than it really is. Suppose you want to treat patients in groups of 3.…
Cohort assignments in clinical trials
Cohorts are very simple in theory but messy in practice. In a clinical trial, a cohort is a group of patients who receive the same treatment. For example, in dose-finding trials, it is very common to treat patients in groups of…
Posted in Clinical trials
Monitoring legacy code that fails silently
Clift Norris and I just posted an article on CodeProject entitled Monitoring Unreliable Scheduled Tasks about some software Clift wrote to resolve problems we had calling some legacy software that would fail silently. His software adds from the outside monitoring and…
Fasting may reduce chemotherapy side-effects
Chemotherapy harms cancer cells as well as normal cells. Chemotherapy is designed to be more harmful to cancer cells than to normal cells, but the damage to normal cells can be brutal. New studies suggest that fasting prior to receiving…
Saving energy by tolerating mistakes
Computer chips can use significantly less energy if they don’t have to be correct all the time. That’s the idea behind PCMOS — probabilistic complementary metal-oxide semiconductor technology. Here’s an excerpt from Technology Review’s article on PCMOS. [Inventor Krishna] Palem’s…
Posted in Computing
Why functional programming hasn't taken off
Bjarne Stroustrup made a comment in an interview about functional programming. He said advocates of functional programming have been in charge of computer science departments for 30 years now, and yet functional programming has hardly been used outside academia. Maybe…
Probability approximations
When I took my first probability course, it seemed like there were an infinite number of approximation theorems to learn, all mysterious. Looking back, there were probably only two or three, and they don’t need to be mysterious. For example,…
Attention span by nationality
The Code Wizard blog posted some anecdotal evidence of attention span varying as a function of nationality. The author looked through the visitor statistics on his blog and observed that Americans spend less time per page than visitors from other countries.…
Posted in Uncategorized
What makes the Mentos-Diet Coke trick work
The American Journal of Physics has an article in the June issue about the physics of dropping Mentos into Diet Coke. The spectacular result depends on physical characteristics of the Mentos, not their chemical composition. Here’s an explanation from the…
Posted in Science
Bugs in food and software
What is an acceptable probability of finding bug parts in a box of cereal? You can’t say zero. As the acceptable probability goes to zero, the price of a box of cereal goes to infinity. In practice, the FDA sets…
