Nuisance

Got to the office this morning to have my IM client inform me that my AIM screen name is signed in from two locations. Presumably I left Pidgin running on my laptop last night. I thought I’d be able to ssh into it and kill the process, but…well; I can certainly ssh into my desktop, and though my laptop has a DHCP-assigned IP rather than a fixed address and cannot have login requests forwarded from the router, I can scan my LAN from my desktop (which I am accessing through ssh) using nmap to find all active hosts on the LAN. Connect to what I find from my desktop, and—curses! My laptop, of course, is not running sshd.

I wonder how many IMs will go astray today?

On vaccines and autism

The traditional argument against the claim that vaccines cause autism is that it’s bunk because there’s no evidence that it’s so, and that the perceived increase in autism prevalence is due to diagnostic substitution and changes in diagnostic criteria. This is most likely true, but somehow not very comforting (even if it makes sense to teachers…), and diagnostic substitution and critereon changes are fairly obscure: They don’t (in themselves) prove that there has been no increase; they merely make it impossible to tell by looking at prevalence data alone.

A more recent study by the British NHS did something different, and provided data completely consistent with this theory, but perhaps more digestible. They measured autism prevalence across age cohorts. If vaccines did cause autism, then the increase in vaccination over the past few decades should correlate to an increase in autism, which would be reflected in an age skew among the autistic: More young people should be autistic than old people, because old people would have been adults by the time mandatory vaccinations were introduced!

Unsurprisingly, it was found that autism prevalence is not associated with age cohorts: The rate is a constant 1% regardless of age (1.8% in men, 0.2% in women). As Dr. Steve Novella put it,

This is vital blow to the vaccine-autism hypothesis, because the vaccine schedule has been increasing over the last 20 years, the MMR was introduced in the early 1990s, and thimerosal exposure has risen and then fallen to almost nothing. Throughout all of these changes, autism rates have remained stable. This is important because in order to demonstrate toxicity you need to demonstrate a dose-response – the higher the exposure to the alleged toxin the greater the risk or severity of the disease or disorder you think is caused by the toxin. This burden of proof was met for smoking and lung cancer – there is a clear dose-risk response. This is no detectable dose-risk link between vaccines and autism.

It will be interesting to see how the antivaxers attempt to explain this away.