May 28th, 2009 ecoli
Some recent freakonomics blog posts of interest.
Much ado about steroids Some claim their steroid habits are safe
Most expensive health care in the world
I’m not sure I agree with this Times article. In this context health care may be over-utilized (and therefore more expensive) not because doctors are acting like entrepreneurs, but because they are acting like entrepreneurs without any regards to price signals. In other words, since everything is covered by insurance, people don’t care about price. (in addition to the fact that nobody wants to be involved in a malpractice suit, so unnecessary tests are ordered).
When consumers aren’t shopping around based on price signals, firms compete to offer the most frills, but not to keep costs down. Maybe the problem with health care isn’t innovative entrepreneurs but the lack of competitive markets (which won’t be solved by making the system universal).
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May 28th, 2009 ecoli
Dr. James Holland Jones has an (older) post on scientific uncertainty and fat tails on his monkey’s uncle blog. Its one of the better explanations I’ve read, so do your self a favor and get educated. He also asks:
As scientists with an interest in policy, how do we communicate this type of uncertainty?
Before you can even ask this question, you have to ask if scientists, biologists in particular, are even interested in communicating uncertainty. Statistics and math are just not stressed in undergrad bio courses, and not at all in high school, so students are coming up with very little conceptions about uncertainty in data. I admit to being guitly of this but, unlike myself, how many scientists are willing to learn? Do their egos permit discussing statistical uncertainty?
This reminds me of one of Jorge Chan’s PhD comics on the science news cycle:
The cycle is exacerbated even in the first step, when scientists are not even well trained to understand or compute uncertainty themselves.
Posted in education, link out, mathematics, musings | No Comments »
May 27th, 2009 ecoli
Even though I technically finished all my undergrad classes, I’m taking an undergrad class this summer, so I still have access to my uni’s library (thank god). Lets kick off the summer reading list:
Disease Evolution: Models, Concepts, and Data Analyses from the DIMACS Series
Growing Artificial Societies: Social Science from the Bottom Up
Learning Python
Fortunes of Liberalism, Essays by FA Hayek
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May 26th, 2009 ecoli
As someone who is about to lose their previous form of health care insurance coverage, I thought the front page “conversation” on scienceblogs is appropriate.
I don’t want to get into the specifics of the debate, but I thought it was especially interesting that the overwhelming perspective on scienceblogs.com is from the left ‘pro-universal’ side. What is it that makes scientists particularly liberal, especially on this issue? Consider that the economics of the issue is far from settled and that scientists are intimately familiar with the darkside of government funding.
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May 21st, 2009 ecoli
This is an interesting program that my friend forwarded to me via twitter.
The big difference between computer typing and typewriting is that there’s no deletion on the typewriter. You could scratch off/white out some letters, but any wide-scale revisions had to be completely re-done.
Writing on a manual [typewriter] makes you slower in a good way, I think. You don’t revise as much, you just think more, because you know you’re going to have to retype the entire fucking thing. Which is a big stop on just slapping anything down and playing with it.
- Will Self
It’s an interesting exercise, because you have to be really careful about the words you’re putting onto the paper, grammar, style, etc. I think practicing with this software is good for people (like myself) who have forgotten how to write carefully. Probably good practice for those timed in-class writing assignments.
The only downside is the program itself… it runs in Java and is a little annoying to use. Still worth fiddling with now and then.
Posted in technology | 3 Comments »
May 21st, 2009 ecoli
This is going to be a multi-part series. As usual, my source.
The way we model the spread of infectious diseases may seem counter intuitive at first. We’re not looking at the movements of the bug, itself but rather populations of individuals infected with a pathogens. We split a general population into different types and describe their infection status, as a group. We then express the frequency of infection/recovery as rates, proportional to that population.
This will become clear in a moment.
Imagine we have a population of individuals who are susceptible to some disease. The infection will be transmitted to some subset of those susceptible individuals at a certain rate, and they become infected. Now, for this model, we assume individuals do not recover, the infection is non-lethal and we will ignore natural birth and death rates of the population.
The schematic for this simple model follows:
where β is the rate of infection (transmission). Since infections spread directly from person to person, the effective population of infected individuals and susceptibles vary directly with the rate. The infection spreads faster if there are more susceptible and infected individuals. We can see the dynamics more effectively with a math model, however. We can describe this schematic with a differential equation:
since the population is closed, S + I = N => S = N – I so,
Lets take a look at this equation: we have linear function of the infected population, varying with βNI. The the stuff in the parenthesis looks like a “saturation” limiter. When the number of total individuals is much higher than the infected, I/N is a small number. 1 minus a small number is close to 1, and you get a linear picture. However, as I approaches N (it can never exceed in this case) I/N = 1. Since 1-1 = 0, growth becomes saturated and, eventually, becomes zero. This looks very much like the logistics equation of population growth (in quadrant 1):
This result is logical: No matter how fast the infection rate is, eventually you’ll run out of new individuals to infect.
This is the last mathbio post I’m going to make in a while, probably.
Posted in mathematics, microbiology | No Comments »
April 18th, 2009 ecoli
Who would have thought that paper made out of Wombat feces would be so popular. But what consumers want, consumers get, right?
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April 16th, 2009 ecoli
I saw a poster for this when I was at Carnegie Hall last week. Looks like the performance was this past Wednesday.
Definitely watch the video: Youtube Symphony Orchestra
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April 13th, 2009 ecoli
From Dr. Jekyll & Mrs. Hyde
I have been spending off hours on PubMed, trying to discover the rational basis for the host of rules pregnant women are adjured to obey:
–Don’t eat unpasteurized cheese (Brie, Gorgonzola, feta, chevre…all the good stuff)
–Don’t eat deli meats unless they’ve been heated to steaming
–Don’t even think about licking the bowl clean of cookie batter
–Sushi? Do you want the baby to die, or what?
–Lying on your back past the fourth month is going to give the critter brain damage
–A sip of wine? Why not just smoke crack and be done with it?
I’m not talking “old wives’ tales your grandmother produces.” These things are specifically listed as fetal death-traps in publications ranging from the leaflets I was handed at the ob-gyn to “What to Expect When You’re Expecting,” probably the single most popular pregnancy book available.
But here’s the funny thing. When you look for actual studies about these things on PubMed, you keep thinking that you’ve entered the wrong search terms, because so little comes up.
Expectant mothers are, generally, hypersensitive to urban legends and even random tidbits that sound like they could be scientifically plausible. Maybe they should chill out.
Posted in link out, medicine, musings | 1 Comment »
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